From: Efraim Flashner <efraim@flashner.co.il>
To: 74609@debbugs.gnu.org
Cc: aaron.covrig.us@ieee.org, ludo@gnu.org,
unmush <unmush@hashbang.sh>,
richard@freakingpenguin.com, unmush@proton.me, janneke@gnu.org
Subject: [bug#74609] [PATCH 18/21] gnu: Add mono-pre-5.10.0.
Date: Mon, 16 Dec 2024 19:26:41 +0200 [thread overview]
Message-ID: <3cbfc5b25a94ed1a917791c8f79b692b6c78b2b2.1734369314.git.efraim@flashner.co.il> (raw)
In-Reply-To: <cover.1734369314.git.efraim@flashner.co.il>
From: unmush <unmush@hashbang.sh>
* gnu/packages/dotnet.scm
(mono-pre-5.10.0-external-repo-specs, mono-pre-5.10.0): New variables.
* gnu/packages/patches/mono-mcs-patches-from-5.10.0.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register new patch.
Change-Id: Ie78dce071032b6743b6e4c2eb58e43bc89e6a1d1
---
gnu/local.mk | 1 +
gnu/packages/dotnet.scm | 73 +
.../mono-mcs-patches-from-5.10.0.patch | 4218 +++++++++++++++++
3 files changed, 4292 insertions(+)
create mode 100644 gnu/packages/patches/mono-mcs-patches-from-5.10.0.patch
diff --git a/gnu/local.mk b/gnu/local.mk
index 2b1a6f7c782..c58bfe73cdb 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1829,6 +1829,7 @@ dist_patch_DATA = \
%D%/packages/patches/mono-4.9.0-fix-runtimemetadataversion.patch \
%D%/packages/patches/mono-5.4.0-patches.patch \
%D%/packages/patches/mono-5.8.0-patches.patch \
+ %D%/packages/patches/mono-mcs-patches-from-5.10.0.patch \
%D%/packages/patches/mosaicatcher-unbundle-htslib.patch \
%D%/packages/patches/mrrescue-support-love-11.patch \
%D%/packages/patches/mtools-mformat-uninitialized.patch \
diff --git a/gnu/packages/dotnet.scm b/gnu/packages/dotnet.scm
index 82fc2033707..414e955340f 100644
--- a/gnu/packages/dotnet.scm
+++ b/gnu/packages/dotnet.scm
@@ -1398,3 +1398,76 @@ (define-public mono-5.8.0
" "
top "/mcs/class/lib/build/mcs.exe")
make-flags)))))))))))
+
+(define mono-pre-5.10.0-external-repo-specs
+ '(("api-doc-tools" "d03e819838c6241f92f90655cb448cc47c9e8791"
+ "1riki79f3ig3cxigviss81dz601hn92a1gifglm0mzjbs76sf3fj"
+ #:recursive? #t)
+ ("api-snapshot" "627333cae84f02a36ee9ca605c96dac4557d9f35"
+ "0p9c6brxiwx38yvaf55jd0l1mxfj3b5ah0xas2hv6frkz80yrqdl")
+ ("aspnetwebstack" "e77b12e6cc5ed260a98447f609e887337e44e299"
+ "0rks344qr4fmp3fs1264d2qkmm348m8d1kjd7z4l94iiirwn1fq1")
+ (("reference-assemblies" "binary-reference-assemblies")
+ "9c5cc7f051a0bba2e41341a5baebfc4d2c2133ef"
+ "14bfn1qvni8gyfxjwmvykyjjy3j5ng4fnbljdadi9dm4b9al0wg1")
+ ("bockbuild" "29022af5d8a94651b2eece93f910559b254ec3f0"
+ "0lclc1smmrj6xw32dll073mxw4ddiixv9arv02yw3w5h135ay7w4")
+ ("boringssl" "3e0770e18835714708860ba9fe1af04a932971ff"
+ "139a0gl91a52k2r6na6ialzkqykaj1rk88zjrkaz3sdxx7nmmg6y")
+ ("cecil" "bc11f472954694ebd92ae4956f110c1036a7c2e0"
+ "122nnp5pcnw18pj6amnqkqxlrmapd4vy9xs65hd0bqyqjh56bwnd")
+ (("cecil" "cecil-legacy") "33d50b874fd527118bc361d83de3d494e8bb55e1"
+ "1p4hl1796ib26ykyf5snl6cj0lx0v7mjh0xqhjw6qdh753nsjyhb")
+ ("corefx" "cb1b049c95227465c1791b857cb5ba86385d9f29"
+ "1pr0qjlgxf63zs1g80gqd6x3qhlgb0wlcc8zm8z8am5aywrvgb53")
+ ("corert" "48dba73801e804e89f00311da99d873f9c550278"
+ "1zw47jf4cwqmaixylisxi73xf6cap41bwf9vlmpxanzxaqklzsvk")
+ ("ikdasm" "465c0815558fd43c0110f8d00fc186ac0044ac6a"
+ "0xir7pcgq04hb7s8g9wsqdrypb6l29raj3iz5rcqzdm0056k75w2")
+ (("ikvm-fork" "ikvm") "847e05fced5c9a41ff0f24f1f9d40d5a8a5772c1"
+ "1fl9bm3lmzf8iqv3x4iqkz9fc54mwdvrxisxg2nvwwcsi4saffpi")
+ ("linker" "99354bf5c13b8055209cb082cddc50c8047ab088"
+ "05zlajnqf83xfvn2whh9nql6j85sq12aw26sqmyqz7zcpml171mj")
+ ("Newtonsoft.Json" "471c3e0803a9f40a0acc8aeceb31de6ff93a52c4"
+ "0dgngd5hqk6yhlg40kabn6qdnknm32zcx9q6bm2w31csnsk5978s")
+ (("NuGet.BuildTasks" "nuget-buildtasks")
+ "b58ba4282377bcefd48abdc2d62ce6330e079abe"
+ "1say03fnqkjsx97zacany3sa5j4mhfk827hkwp23ib02q18f7lvp")
+ (("NUnitLite" "nunit-lite") "764656cdafdb3acd25df8cb52a4e0ea14760fccd"
+ "0pc7lk3p916is8cn4ngaqvjlmlzv3vvjpyksy4pvb3qb5iiaw0vq")
+ ;; ("roslyn-binaries" "1904c7d0682a878e2d25b4d49f3475d12fbb9cc6"
+ ;; "")
+ ("rx" "b29a4b0fda609e0af33ff54ed13652b6ccf0e05e"
+ "1n1jwhmsbkcv2d806immcpzkb72rz04xy98myw355a8w5ah25yiv")
+ ;; ("xunit-binaries" "d4433b0972f40cb3efaa3fbba52869bde5df8fa8"
+ ;; "")
+ ))
+
+(define-public mono-pre-5.10.0
+ (let ((commit "3e9d7d6e9cf8dc33eb29c497c350a1cd7df3a057")
+ (version "5.8.0.129")
+ (revision "0"))
+ (package
+ (inherit mono-5.8.0)
+ (version (git-version version revision commit))
+ (name "mono")
+ (source (origin
+ (method git-fetch)
+ (uri
+ (git-reference
+ (url "https://gitlab.winehq.org/mono/mono.git")
+ (commit commit)))
+ (file-name (git-file-name name version))
+ (sha256
+ (base32
+ "0m8i0zgzh0fgb3ssy95v9czk1c0rl76q0jj7834s5fjnkdj8l4jb"))
+ (modules '((guix build utils)
+ (ice-9 string-fun)))
+ (snippet #~(begin
+ #$(add-external-repos
+ mono-pre-5.10.0-external-repo-specs)
+ #$@prepare-mono-source-0))
+ (patches
+ (search-patches "mono-mcs-patches-from-5.10.0.patch"))))
+ (native-inputs (modify-inputs (package-native-inputs mono-5.8.0)
+ (replace "mono" mono-5.8.0))))))
diff --git a/gnu/packages/patches/mono-mcs-patches-from-5.10.0.patch b/gnu/packages/patches/mono-mcs-patches-from-5.10.0.patch
new file mode 100644
index 00000000000..41dfed7df7f
--- /dev/null
+++ b/gnu/packages/patches/mono-mcs-patches-from-5.10.0.patch
@@ -0,0 +1,4218 @@
+Includes the following commits:
+6f5bfe5cf5a
+3812d1c13fc
+a80f3d0d87c
+b2f051f0b19
+2a202a8478b
+4d7d1606d73
+d9970305731
+94e80fc8d7f
+0b9280083a9
+07d1e5f36a5
+5f279f14aa2
+889421f3bef
+f4c0fd3dc11
+71df5c63b46
+d6e5bf16782
+207f5c2cd6d
+c512752a416
+9aca8d5fe4b
+diff --git a/mcs/class/Mono.CSharp/Test/Evaluator/TypesTest.cs b/mcs/class/Mono.CSharp/Test/Evaluator/TypesTest.cs
+index 97f9e047e6d..f8bf63455de 100644
+--- a/mcs/class/Mono.CSharp/Test/Evaluator/TypesTest.cs
++++ b/mcs/class/Mono.CSharp/Test/Evaluator/TypesTest.cs
+@@ -131,5 +131,17 @@ namespace MonoTests.EvaluatorTest
+ {
+ Evaluator.Run ("public class TestClass { private TestEnum _te; public string Get() { return _te.ToString(); } } public enum TestEnum { First, Second }");
+ }
++
++ [Test]
++ public void EnumTypeWithOrderDependency ()
++ {
++ Evaluator.Run ("public class TestClass { public enum TestEnum { Val1, Val2, Val3 } public TestEnum test; public TestClass() { test = TestEnum.Val3; } }");
++ object res = Evaluator.Evaluate ("new TestClass()");
++
++ var fields = res.GetType ().GetFields ();
++ foreach (var field in fields) {
++ Console.WriteLine ($"{field.Name} = {field.MemberType}");
++ }
++ }
+ }
+ }
+\ No newline at end of file
+diff --git a/mcs/errors/cs0023-30.cs b/mcs/errors/cs0023-30.cs
+new file mode 100644
+index 00000000000..fc19cc24e3e
+--- /dev/null
++++ b/mcs/errors/cs0023-30.cs
+@@ -0,0 +1,11 @@
++// CS0023: The `is' operator cannot be applied to operand of type `default'
++// Line: 9
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main ()
++ {
++ bool d = default is C;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0029-39.cs b/mcs/errors/cs0029-39.cs
+new file mode 100644
+index 00000000000..0ed200036dc
+--- /dev/null
++++ b/mcs/errors/cs0029-39.cs
+@@ -0,0 +1,15 @@
++// CS0029: Cannot implicitly convert type `S' to `object'
++// Line: 13
++// Compiler options: -langversion:latest
++
++public ref struct S
++{
++}
++
++class Test
++{
++ public static void Main ()
++ {
++ object o = new S ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0029-40.cs b/mcs/errors/cs0029-40.cs
+new file mode 100644
+index 00000000000..6d9167c31fa
+--- /dev/null
++++ b/mcs/errors/cs0029-40.cs
+@@ -0,0 +1,19 @@
++// CS0029: Cannot implicitly convert type `S' to `System.ValueType'
++// Line: 16
++// Compiler options: -langversion:latest
++
++using System;
++
++public ref struct S
++{
++}
++
++class Test
++{
++ public static void Main ()
++ {
++ var s = default (S);
++ ValueType s2 = s;
++ var res = default (S).ToString ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0029-41.cs b/mcs/errors/cs0029-41.cs
+new file mode 100644
+index 00000000000..1a65f52f737
+--- /dev/null
++++ b/mcs/errors/cs0029-41.cs
+@@ -0,0 +1,12 @@
++// CS0029: Cannot implicitly convert type `System.TypedReference' to `object'
++// Line: 10
++
++using System;
++
++class Test
++{
++ public static void Main ()
++ {
++ var res = default (TypedReference).ToString ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0029-42.cs b/mcs/errors/cs0029-42.cs
+new file mode 100644
+index 00000000000..c7671000c76
+--- /dev/null
++++ b/mcs/errors/cs0029-42.cs
+@@ -0,0 +1,10 @@
++// CS0029: Cannot implicitly convert type `string' to `int'
++// Line: 8
++
++class C
++{
++ void Exists (int _)
++ {
++ _ = "2";
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0030-17.cs b/mcs/errors/cs0030-17.cs
+new file mode 100644
+index 00000000000..b72b8bf71e5
+--- /dev/null
++++ b/mcs/errors/cs0030-17.cs
+@@ -0,0 +1,15 @@
++// CS0030: Cannot convert type `object' to `S'
++// Line: 13
++// Compiler options: -langversion:latest
++
++ref struct S
++{
++}
++
++class X
++{
++ public static void Foo (object o)
++ {
++ var res = (S) o;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0103-18.cs b/mcs/errors/cs0103-18.cs
+new file mode 100644
+index 00000000000..8cec755d23d
+--- /dev/null
++++ b/mcs/errors/cs0103-18.cs
+@@ -0,0 +1,10 @@
++// CS0103: The name `_' does not exist in the current context
++// Line: 8
++
++class C
++{
++ void Test ()
++ {
++ _.ToString ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0123-10.cs b/mcs/errors/cs0123-10.cs
+new file mode 100644
+index 00000000000..43d5e5d6368
+--- /dev/null
++++ b/mcs/errors/cs0123-10.cs
+@@ -0,0 +1,18 @@
++// CS0123: A method or delegate `object.ToString()' parameters do not match delegate `System.Func<string>()' parameters
++// Line: 16
++// Compiler options: -langversion:latest
++
++using System;
++
++public ref struct S
++{
++}
++
++class Test
++{
++ public static void Main ()
++ {
++ var s = new S ();
++ Func<string> f = s.ToString;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0123-11.cs b/mcs/errors/cs0123-11.cs
+new file mode 100644
+index 00000000000..427b628c159
+--- /dev/null
++++ b/mcs/errors/cs0123-11.cs
+@@ -0,0 +1,12 @@
++// CS0123: A method or delegate `object.ToString()' parameters do not match delegate `System.Func<string>()' parameters
++// Line: 16
++
++using System;
++
++class Test
++{
++ public static void Main ()
++ {
++ Func<string> f = default (TypedReference).ToString;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0133-2.cs b/mcs/errors/cs0133-2.cs
+index b7a37182d73..48488876f7e 100644
+--- a/mcs/errors/cs0133-2.cs
++++ b/mcs/errors/cs0133-2.cs
+@@ -1,4 +1,4 @@
+-// CS0133: The expression being assigned to `c' must be constant
++// CS0133: The expression being assigned to `c' must be a constant or default value
+ // Line: 10
+
+ class C
+diff --git a/mcs/errors/cs0133-3.cs b/mcs/errors/cs0133-3.cs
+index caae3bde68c..2f7dac6880d 100644
+--- a/mcs/errors/cs0133-3.cs
++++ b/mcs/errors/cs0133-3.cs
+@@ -1,5 +1,5 @@
+-// CS0133: The expression being assigned to `Foo' must be constant
+-// Line: 12
++// CS0133: The expression being assigned to `Foo' must be a constant or default value
++// Line: 8
+
+ class T
+ {
+diff --git a/mcs/errors/cs0133-4.cs b/mcs/errors/cs0133-4.cs
+index 41fe639b446..54162d544ca 100644
+--- a/mcs/errors/cs0133-4.cs
++++ b/mcs/errors/cs0133-4.cs
+@@ -1,4 +1,4 @@
+-// CS0133: The expression being assigned to `S.pathName' must be constant
++// CS0133: The expression being assigned to `S.pathName' must be a constant or default value
+ // Line: 12
+ // Compiler options: -unsafe
+
+diff --git a/mcs/errors/cs0133-5.cs b/mcs/errors/cs0133-5.cs
+index a49f265c690..32e6bfdf416 100644
+--- a/mcs/errors/cs0133-5.cs
++++ b/mcs/errors/cs0133-5.cs
+@@ -1,4 +1,4 @@
+-// CS0133: The expression being assigned to `b' must be constant
++// CS0133: The expression being assigned to `b' must be a constant or default value
+ // Line: 8
+
+ class X
+diff --git a/mcs/errors/cs0133-6.cs b/mcs/errors/cs0133-6.cs
+index a523169cdbd..28448dd6de8 100644
+--- a/mcs/errors/cs0133-6.cs
++++ b/mcs/errors/cs0133-6.cs
+@@ -1,4 +1,4 @@
+-// CS0133: The expression being assigned to `o' must be constant
++// CS0133: The expression being assigned to `o' must be a constant or default value
+ // Line: 8
+
+ class X
+diff --git a/mcs/errors/cs0133-7.cs b/mcs/errors/cs0133-7.cs
+index 10d82d9fe5e..024bc148229 100644
+--- a/mcs/errors/cs0133-7.cs
++++ b/mcs/errors/cs0133-7.cs
+@@ -1,4 +1,4 @@
+-// CS0133: The expression being assigned to `o' must be constant
++// CS0133: The expression being assigned to `o' must be a constant or default value
+ // Line: 8
+
+ class X
+diff --git a/mcs/errors/cs0133.cs b/mcs/errors/cs0133.cs
+index 094194deabb..f0dda9ee3cb 100644
+--- a/mcs/errors/cs0133.cs
++++ b/mcs/errors/cs0133.cs
+@@ -1,5 +1,6 @@
+-// CS0133: The expression being assigned to `x' must be constant
+-// Line: 6
++// CS0133: The expression being assigned to `x' must be a constant or default value
++// Line: 7
++
+ class X {
+ X (int arg)
+ {
+diff --git a/mcs/errors/cs0306-4.cs b/mcs/errors/cs0306-4.cs
+new file mode 100644
+index 00000000000..4653512e55b
+--- /dev/null
++++ b/mcs/errors/cs0306-4.cs
+@@ -0,0 +1,15 @@
++// CS0306: The type `S' may not be used as a type argument
++// Line: 13
++// Compiler options: -langversion:latest
++
++public ref struct S
++{
++}
++
++class Test<T>
++{
++ public static void Foo ()
++ {
++ Test<S> local;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0611-3.cs b/mcs/errors/cs0611-3.cs
+new file mode 100644
+index 00000000000..6eda773dd24
+--- /dev/null
++++ b/mcs/errors/cs0611-3.cs
+@@ -0,0 +1,15 @@
++// CS0611: Array elements cannot be of type `S'
++// Line: 13
++// Compiler options: -langversion:latest
++
++public ref struct S
++{
++}
++
++class Test
++{
++ public static void Main ()
++ {
++ var x = new S[0];
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs0815-9.cs b/mcs/errors/cs0815-9.cs
+new file mode 100644
+index 00000000000..f54703349be
+--- /dev/null
++++ b/mcs/errors/cs0815-9.cs
+@@ -0,0 +1,11 @@
++// CS0815: An implicitly typed local variable declaration cannot be initialized with `default'
++// Line: 9
++// Compiler options: -langversion:latest
++
++static class X
++{
++ public static void Main ()
++ {
++ var x = default;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs1502-11.cs b/mcs/errors/cs1502-11.cs
+deleted file mode 100644
+index 82dcb3a2c17..00000000000
+--- a/mcs/errors/cs1502-11.cs
++++ /dev/null
+@@ -1,11 +0,0 @@
+-// CS1502: The best overloaded method match for `string.String(char*)' has some invalid arguments
+-// Line: 8
+-
+-class C
+-{
+- static string Prop {
+- get {
+- return new string ("s");
+- }
+- }
+-}
+diff --git a/mcs/errors/cs1599-2.cs b/mcs/errors/cs1599-2.cs
+index 941ff6bb0d6..28aa05b2ed3 100644
+--- a/mcs/errors/cs1599-2.cs
++++ b/mcs/errors/cs1599-2.cs
+@@ -1,4 +1,4 @@
+-// CS1599: Method or delegate cannot return type `System.ArgIterator'
++// CS1599: The return type of `System.ArgIterator' is not allowed
+ // Line: 8
+
+ using System;
+diff --git a/mcs/errors/cs1599-3.cs b/mcs/errors/cs1599-3.cs
+index e4869dcaf70..9d378099d82 100644
+--- a/mcs/errors/cs1599-3.cs
++++ b/mcs/errors/cs1599-3.cs
+@@ -1,4 +1,4 @@
+-// CS1599: Method or delegate cannot return type `System.ArgIterator'
++// CS1599: The return type of `System.ArgIterator' is not allowed
+ // Line: 8
+
+ using System;
+diff --git a/mcs/errors/cs1599-4.cs b/mcs/errors/cs1599-4.cs
+new file mode 100644
+index 00000000000..358eee59a13
+--- /dev/null
++++ b/mcs/errors/cs1599-4.cs
+@@ -0,0 +1,12 @@
++// CS1599: The return type of `System.TypedReference' is not allowed
++// Line: 8
++
++using System;
++
++public class Program
++{
++ public static TypedReference operator + (int a, Program b)
++ {
++ throw new ApplicationException ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs1599.cs b/mcs/errors/cs1599.cs
+index 5cef32d7f97..871d9fb3e7a 100644
+--- a/mcs/errors/cs1599.cs
++++ b/mcs/errors/cs1599.cs
+@@ -1,4 +1,4 @@
+-// CS1599: Method or delegate cannot return type `System.TypedReference'
++// CS1599: The return type of `System.TypedReference' is not allowed
+ // Line: 8
+
+ using System;
+diff --git a/mcs/errors/cs1644-57.cs b/mcs/errors/cs1644-57.cs
+new file mode 100644
+index 00000000000..7ee98373080
+--- /dev/null
++++ b/mcs/errors/cs1644-57.cs
+@@ -0,0 +1,7 @@
++// CS1644: Feature `ref structs' cannot be used because it is not part of the C# 7.0 language specification
++// Line: 5
++// Compiler options: -langversion:7
++
++ref struct S
++{
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs1644-58.cs b/mcs/errors/cs1644-58.cs
+new file mode 100644
+index 00000000000..e994cf338bd
+--- /dev/null
++++ b/mcs/errors/cs1644-58.cs
+@@ -0,0 +1,8 @@
++// CS1644: Feature `default literal' cannot be used because it is not part of the C# 7.0 language specification
++// Line: 7
++// Compiler options: -langversion:7
++
++class X
++{
++ int i = default;
++}
+diff --git a/mcs/errors/cs1644-59.cs b/mcs/errors/cs1644-59.cs
+new file mode 100644
+index 00000000000..2f8aed6b958
+--- /dev/null
++++ b/mcs/errors/cs1644-59.cs
+@@ -0,0 +1,13 @@
++// CS1644: Feature `readonly references' cannot be used because it is not part of the C# 7.0 language specification
++// Line: 9
++// Compiler options: -langversion:7
++
++class X
++{
++ int i;
++
++ ref readonly int Test ()
++ {
++ return ref i;
++ }
++}
+diff --git a/mcs/errors/cs1644-60.cs b/mcs/errors/cs1644-60.cs
+new file mode 100644
+index 00000000000..ca9547bc561
+--- /dev/null
++++ b/mcs/errors/cs1644-60.cs
+@@ -0,0 +1,11 @@
++// CS1644: Feature `discards' cannot be used because it is not part of the C# 6.0 language specification
++// Line: 9
++// Compiler options: -langversion:6
++
++class X
++{
++ int Test ()
++ {
++ _ = 2;
++ }
++}
+diff --git a/mcs/errors/cs1738-2.cs b/mcs/errors/cs1738-2.cs
+index f59221f4c7a..44b3f6d1b14 100644
+--- a/mcs/errors/cs1738-2.cs
++++ b/mcs/errors/cs1738-2.cs
+@@ -1,4 +1,4 @@
+-// CS1738: Named arguments must appear after the positional arguments
++// CS1738: Named arguments must appear after the positional arguments when using language version older than 7.2
+ // Line: 13
+
+ using System;
+diff --git a/mcs/errors/cs1738-3.cs b/mcs/errors/cs1738-3.cs
+index 53c4efc3553..901ac0e5d59 100644
+--- a/mcs/errors/cs1738-3.cs
++++ b/mcs/errors/cs1738-3.cs
+@@ -1,4 +1,4 @@
+-// CS1738: Named arguments must appear after the positional arguments
++// CS1738: Named arguments must appear after the positional arguments when using language version older than 7.2
+ // Line: 14
+
+ class C
+diff --git a/mcs/errors/cs1738.cs b/mcs/errors/cs1738.cs
+index dab9a61160b..537bc17b917 100644
+--- a/mcs/errors/cs1738.cs
++++ b/mcs/errors/cs1738.cs
+@@ -1,4 +1,4 @@
+-// CS1738: Named arguments must appear after the positional arguments
++// CS1738: Named arguments must appear after the positional arguments when using language version older than 7.2
+ // Line: 12
+
+ class C
+diff --git a/mcs/errors/cs1983.cs b/mcs/errors/cs1983.cs
+index a2ef6c150d6..76d2db4e677 100644
+--- a/mcs/errors/cs1983.cs
++++ b/mcs/errors/cs1983.cs
+@@ -1,4 +1,4 @@
+-// CS1983: The return type of an async method must be void, Task, or Task<T>
++// CS1983: The return type of an async method must be void or task type
+ // Line: 6
+
+ class C
+diff --git a/mcs/errors/cs4012-3.cs b/mcs/errors/cs4012-3.cs
+new file mode 100644
+index 00000000000..fb3d1dc276f
+--- /dev/null
++++ b/mcs/errors/cs4012-3.cs
+@@ -0,0 +1,19 @@
++// CS4012: Parameters or local variables of type `S' cannot be declared in async methods or iterators
++// Line: 16
++// Compiler options: -langversion:latest
++
++using System;
++using System.Threading.Tasks;
++
++public ref struct S
++{
++}
++
++class C
++{
++ public async void Test ()
++ {
++ var tr = new S ();
++ await Task.Factory.StartNew (() => 6);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8175-2.cs b/mcs/errors/cs8175-2.cs
+new file mode 100644
+index 00000000000..27c4babf8bf
+--- /dev/null
++++ b/mcs/errors/cs8175-2.cs
+@@ -0,0 +1,19 @@
++// CS8175: Cannot use by-reference variable `s' inside an anonymous method, lambda expression, or query expression
++// Line: 17
++// Compiler options: -langversion:latest
++
++using System;
++
++public ref struct S
++{
++}
++
++class Test
++{
++ public static void Main ()
++ {
++ var s = new S ();
++
++ Action a = () => Console.WriteLine (s);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8183.cs b/mcs/errors/cs8183.cs
+new file mode 100644
+index 00000000000..f9e9004b737
+--- /dev/null
++++ b/mcs/errors/cs8183.cs
+@@ -0,0 +1,11 @@
++// CS8183: Cannot infer the type of implicitly-typed discard
++// Line: 9
++// Compiler options: -langversion:7.2
++
++class X
++{
++ public static void Main ()
++ {
++ _ = default;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8184.cs b/mcs/errors/cs8184.cs
+new file mode 100644
+index 00000000000..19a4685d7bd
+--- /dev/null
++++ b/mcs/errors/cs8184.cs
+@@ -0,0 +1,10 @@
++// CS8184: A deconstruction cannot mix declarations and expressions on the left-hand-side
++// Line: 8
++
++class X
++{
++ public static void Main ()
++ {
++ (int a, b) = (1, 2);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8207.cs b/mcs/errors/cs8207.cs
+new file mode 100644
+index 00000000000..31090948b45
+--- /dev/null
++++ b/mcs/errors/cs8207.cs
+@@ -0,0 +1,19 @@
++// CS8207: An expression tree cannot contain a discard
++// Line: 11
++
++using System;
++using System.Linq.Expressions;
++
++class X
++{
++ void Test ()
++ {
++ Expression<Func<bool>> e = () => TryGetValue (out _);
++ }
++
++ bool TryGetValue (out int arg)
++ {
++ arg = 3;
++ return true;
++ }
++}
+diff --git a/mcs/errors/cs8209.cs b/mcs/errors/cs8209.cs
+new file mode 100644
+index 00000000000..3a46a206c8e
+--- /dev/null
++++ b/mcs/errors/cs8209.cs
+@@ -0,0 +1,10 @@
++// CS8209: Cannot assign void to a discard
++// Line: 8
++
++class C
++{
++ public static void Main ()
++ {
++ _ = Main ();
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8310.cs b/mcs/errors/cs8310.cs
+new file mode 100644
+index 00000000000..134624c03b7
+--- /dev/null
++++ b/mcs/errors/cs8310.cs
+@@ -0,0 +1,11 @@
++// CS8310: Operator `+' cannot be applied to operand `default'
++// Line: 9
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main ()
++ {
++ int h = 1 + default;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8311.cs b/mcs/errors/cs8311.cs
+new file mode 100644
+index 00000000000..5b35229442d
+--- /dev/null
++++ b/mcs/errors/cs8311.cs
+@@ -0,0 +1,12 @@
++// CS8311: Cannot use a default literal as an argument to a dynamically dispatched operation
++// Line: 10
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main ()
++ {
++ dynamic d = null;
++ d.M2 (default);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8312.cs b/mcs/errors/cs8312.cs
+new file mode 100644
+index 00000000000..d2ad3f52f02
+--- /dev/null
++++ b/mcs/errors/cs8312.cs
+@@ -0,0 +1,12 @@
++// CS8312: Use of default literal is not valid in this context
++// Line: 9
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main ()
++ {
++ foreach (var x in default) {
++ }
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8315.cs b/mcs/errors/cs8315.cs
+new file mode 100644
+index 00000000000..c40bf8613b4
+--- /dev/null
++++ b/mcs/errors/cs8315.cs
+@@ -0,0 +1,11 @@
++// CS8315: Operator `==' is ambiguous on operands `default' and `default'
++// Line: 9
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main ()
++ {
++ bool d = default == default;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8323.cs b/mcs/errors/cs8323.cs
+new file mode 100644
+index 00000000000..c6c9309ec0d
+--- /dev/null
++++ b/mcs/errors/cs8323.cs
+@@ -0,0 +1,15 @@
++// CS8323: Named argument `str' is used out of position but is followed by positional argument
++// Line: 9
++// Compiler options: -langversion:7.2
++
++class X
++{
++ public static void Main ()
++ {
++ Test (str: "", "");
++ }
++
++ static void Test (int arg, string str)
++ {
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8324.cs b/mcs/errors/cs8324.cs
+new file mode 100644
+index 00000000000..8a0be1aefb9
+--- /dev/null
++++ b/mcs/errors/cs8324.cs
+@@ -0,0 +1,12 @@
++// CS8324: Named argument specifications must appear after all fixed arguments have been specified in a dynamic invocation
++// Line: 10
++// Compiler options: -langversion:7.2
++
++class C
++{
++ void M ()
++ {
++ dynamic d = new object ();
++ d.M (arg: 1, "");
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8343.cs b/mcs/errors/cs8343.cs
+new file mode 100644
+index 00000000000..b6aa8e83a09
+--- /dev/null
++++ b/mcs/errors/cs8343.cs
+@@ -0,0 +1,12 @@
++// CS8343: `S': ref structs cannot implement interfaces
++// Line: 7
++// Compiler options: -langversion:latest
++
++using System;
++
++public ref struct S : IDisposable
++{
++ public void Dispose ()
++ {
++ }
++}
+diff --git a/mcs/errors/cs8345-2.cs b/mcs/errors/cs8345-2.cs
+new file mode 100644
+index 00000000000..3f6137b1b56
+--- /dev/null
++++ b/mcs/errors/cs8345-2.cs
+@@ -0,0 +1,12 @@
++// CS8345: Field or auto-implemented property cannot be of type `S' unless it is an instance member of a ref struct
++// Line: 11
++// Compiler options: -langversion:latest
++
++public ref struct S
++{
++}
++
++ref struct Test
++{
++ static S field;
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8345.cs b/mcs/errors/cs8345.cs
+new file mode 100644
+index 00000000000..0b5bd05518f
+--- /dev/null
++++ b/mcs/errors/cs8345.cs
+@@ -0,0 +1,12 @@
++// CS8345: Field or auto-implemented property cannot be of type `S' unless it is an instance member of a ref struct
++// Line: 11
++// Compiler options: -langversion:latest
++
++public ref struct S
++{
++}
++
++struct Test
++{
++ S field;
++}
+\ No newline at end of file
+diff --git a/mcs/errors/cs8346.cs b/mcs/errors/cs8346.cs
+new file mode 100644
+index 00000000000..58e22a2ae7f
+--- /dev/null
++++ b/mcs/errors/cs8346.cs
+@@ -0,0 +1,13 @@
++// CS8346: Cannot convert a stackalloc expression of type `byte' to type `System.Span<int>'
++// Line: 11
++// Compiler options: -langversion:7.2
++
++using System;
++
++class X
++{
++ public static void Main ()
++ {
++ Span<int> stackSpan = stackalloc byte[1];
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/mcs/argument.cs b/mcs/mcs/argument.cs
+index 8421b4dfbfc..5b1003dbadf 100644
+--- a/mcs/mcs/argument.cs
++++ b/mcs/mcs/argument.cs
+@@ -106,11 +106,6 @@ namespace Mono.CSharp
+
+ public virtual Expression CreateExpressionTree (ResolveContext rc)
+ {
+- if (Type.Kind == MemberKind.ByRef) {
+- rc.Report.Error (8153, Expr.Location, "An expression tree lambda cannot contain a call to a method, property, or indexer that returns by reference");
+- return null;
+- }
+-
+ if (ArgType == AType.Default)
+ rc.Report.Error (854, Expr.Location, "An expression tree cannot contain an invocation which uses optional parameter");
+
+diff --git a/mcs/mcs/assign.cs b/mcs/mcs/assign.cs
+index a07c8c0ef39..596623feae4 100644
+--- a/mcs/mcs/assign.cs
++++ b/mcs/mcs/assign.cs
+@@ -391,9 +391,21 @@ namespace Mono.CSharp {
+ return System.Linq.Expressions.Expression.Assign (target_object, source_object);
+ }
+
+- protected virtual Expression ResolveConversions (ResolveContext ec)
++ protected virtual Expression ResolveConversions (ResolveContext rc)
+ {
+- source = Convert.ImplicitConversionRequired (ec, source, target.Type, source.Location);
++ var ttype = target.Type;
++ var stackAlloc = source as StackAlloc;
++ if (stackAlloc != null && ttype.Arity == 1 && ttype.GetDefinition () == rc.Module.PredefinedTypes.SpanGeneric.TypeSpec &&
++ rc.Module.Compiler.Settings.Version >= LanguageVersion.V_7_2) {
++
++ var etype = ttype.TypeArguments [0];
++ var stype = ((PointerContainer)source.Type).Element;
++ if (etype == stype && stackAlloc.ResolveSpanConversion (rc, ttype)) {
++ return this;
++ }
++ }
++
++ source = Convert.ImplicitConversionRequired (rc, source, ttype, source.Location);
+ if (source == null)
+ return null;
+
+diff --git a/mcs/mcs/async.cs b/mcs/mcs/async.cs
+index fd6499346e8..643aed5e568 100644
+--- a/mcs/mcs/async.cs
++++ b/mcs/mcs/async.cs
+@@ -628,58 +628,112 @@ namespace Mono.CSharp
+
+ protected override bool DoDefineMembers ()
+ {
+- PredefinedType builder_type;
+- PredefinedMember<MethodSpec> bf;
+- PredefinedMember<MethodSpec> bs;
+- PredefinedMember<MethodSpec> sr;
+- PredefinedMember<MethodSpec> se;
+- PredefinedMember<MethodSpec> sm;
++ TypeSpec bt;
+ bool has_task_return_type = false;
+- var pred_members = Module.PredefinedMembers;
++ var istate_machine = Module.PredefinedTypes.IAsyncStateMachine;
++ MethodSpec set_statemachine;
+
+- if (return_type.Kind == MemberKind.Void) {
+- builder_type = Module.PredefinedTypes.AsyncVoidMethodBuilder;
+- bf = pred_members.AsyncVoidMethodBuilderCreate;
+- bs = pred_members.AsyncVoidMethodBuilderStart;
+- sr = pred_members.AsyncVoidMethodBuilderSetResult;
+- se = pred_members.AsyncVoidMethodBuilderSetException;
+- sm = pred_members.AsyncVoidMethodBuilderSetStateMachine;
+- } else if (return_type == Module.PredefinedTypes.Task.TypeSpec) {
+- builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilder;
+- bf = pred_members.AsyncTaskMethodBuilderCreate;
+- bs = pred_members.AsyncTaskMethodBuilderStart;
+- sr = pred_members.AsyncTaskMethodBuilderSetResult;
+- se = pred_members.AsyncTaskMethodBuilderSetException;
+- sm = pred_members.AsyncTaskMethodBuilderSetStateMachine;
+- task = pred_members.AsyncTaskMethodBuilderTask.Get ();
++ if (return_type.IsCustomTaskType ()) {
++ //
++ // TODO: Would be nice to cache all this on per-type basis
++ //
++ var btypes = Compiler.BuiltinTypes;
++ bt = return_type.MemberDefinition.GetAsyncMethodBuilder ();
++ TypeSpec bt_inflated;
++ if (return_type.IsGeneric) {
++ bt_inflated = bt.MakeGenericType (Module, bt.MemberDefinition.TypeParameters);
++ } else {
++ bt_inflated = bt;
++ }
++
++ var set_result_sign = MemberFilter.Method ("SetResult", 0, ParametersCompiled.CreateFullyResolved (bt.MemberDefinition.TypeParameters), btypes.Void);
++ set_result = new PredefinedMember<MethodSpec> (Module, bt, set_result_sign).Resolve (Location);
++
++ var set_exception_sign = MemberFilter.Method ("SetException", 0, ParametersCompiled.CreateFullyResolved (btypes.Exception), btypes.Void);
++ set_exception = new PredefinedMember<MethodSpec> (Module, bt, set_exception_sign).Resolve (Location);
++
++ var builder_factory_sign = MemberFilter.Method ("Create", 0, ParametersCompiled.EmptyReadOnlyParameters, bt_inflated);
++ builder_factory = new PredefinedMember<MethodSpec> (Module, bt, builder_factory_sign).Resolve (Location);
++ if (builder_factory?.IsStatic == false)
++ throw new NotImplementedException ("report better error message");
++
++ var builder_start_sign = MemberFilter.Method ("Start", 1, new ParametersImported (
++ new [] {
++ new ParameterData (null, Parameter.Modifier.REF),
++ },
++ new [] {
++ new TypeParameterSpec (0, null, SpecialConstraint.None, Variance.None, null),
++ }, false),
++ btypes.Void);
++ builder_start = new PredefinedMember<MethodSpec> (Module, bt, builder_start_sign).Resolve (Location);
++
++ if (!istate_machine.Define ())
++ return false;
++
++ var set_statemachine_sign = MemberFilter.Method ("SetStateMachine", 0, ParametersCompiled.CreateFullyResolved (istate_machine.TypeSpec), btypes.Void);
++ set_statemachine = new PredefinedMember<MethodSpec> (Module, bt, set_statemachine_sign).Resolve (Location); ;
++
++ var task_sign = MemberFilter.Property ("Task", return_type.MemberDefinition as TypeSpec);
++ task = new PredefinedMember<PropertySpec> (Module, bt, task_sign).Resolve (Location);
++
++ if (set_result == null || set_exception == null || builder_factory == null || builder_start == null || set_statemachine == null || task == null ||
++ !Module.PredefinedTypes.INotifyCompletion.Define ()) {
++ return false;
++ }
++
++ has_task_return_type = return_type.IsGeneric;
+ } else {
+- builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilderGeneric;
+- bf = pred_members.AsyncTaskMethodBuilderGenericCreate;
+- bs = pred_members.AsyncTaskMethodBuilderGenericStart;
+- sr = pred_members.AsyncTaskMethodBuilderGenericSetResult;
+- se = pred_members.AsyncTaskMethodBuilderGenericSetException;
+- sm = pred_members.AsyncTaskMethodBuilderGenericSetStateMachine;
+- task = pred_members.AsyncTaskMethodBuilderGenericTask.Get ();
+- has_task_return_type = true;
+- }
++ PredefinedType builder_type;
++ PredefinedMember<MethodSpec> bf;
++ PredefinedMember<MethodSpec> bs;
++ PredefinedMember<MethodSpec> sr;
++ PredefinedMember<MethodSpec> se;
++ PredefinedMember<MethodSpec> sm;
++ var pred_members = Module.PredefinedMembers;
++
++ if (return_type.Kind == MemberKind.Void) {
++ builder_type = Module.PredefinedTypes.AsyncVoidMethodBuilder;
++ bf = pred_members.AsyncVoidMethodBuilderCreate;
++ bs = pred_members.AsyncVoidMethodBuilderStart;
++ sr = pred_members.AsyncVoidMethodBuilderSetResult;
++ se = pred_members.AsyncVoidMethodBuilderSetException;
++ sm = pred_members.AsyncVoidMethodBuilderSetStateMachine;
++ } else if (return_type == Module.PredefinedTypes.Task.TypeSpec) {
++ builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilder;
++ bf = pred_members.AsyncTaskMethodBuilderCreate;
++ bs = pred_members.AsyncTaskMethodBuilderStart;
++ sr = pred_members.AsyncTaskMethodBuilderSetResult;
++ se = pred_members.AsyncTaskMethodBuilderSetException;
++ sm = pred_members.AsyncTaskMethodBuilderSetStateMachine;
++ task = pred_members.AsyncTaskMethodBuilderTask.Get ();
++ } else {
++ builder_type = Module.PredefinedTypes.AsyncTaskMethodBuilderGeneric;
++ bf = pred_members.AsyncTaskMethodBuilderGenericCreate;
++ bs = pred_members.AsyncTaskMethodBuilderGenericStart;
++ sr = pred_members.AsyncTaskMethodBuilderGenericSetResult;
++ se = pred_members.AsyncTaskMethodBuilderGenericSetException;
++ sm = pred_members.AsyncTaskMethodBuilderGenericSetStateMachine;
++ task = pred_members.AsyncTaskMethodBuilderGenericTask.Get ();
++ has_task_return_type = true;
++ }
+
+- set_result = sr.Get ();
+- set_exception = se.Get ();
+- builder_factory = bf.Get ();
+- builder_start = bs.Get ();
++ set_result = sr.Get ();
++ set_exception = se.Get ();
++ builder_factory = bf.Get ();
++ builder_start = bs.Get ();
+
+- var istate_machine = Module.PredefinedTypes.IAsyncStateMachine;
+- var set_statemachine = sm.Get ();
+-
+- if (!builder_type.Define () || !istate_machine.Define () || set_result == null || builder_factory == null ||
+- set_exception == null || set_statemachine == null || builder_start == null ||
+- !Module.PredefinedTypes.INotifyCompletion.Define ()) {
+- Report.Error (1993, Location,
+- "Cannot find compiler required types for asynchronous functions support. Are you targeting the wrong framework version?");
+- return base.DoDefineMembers ();
+- }
++ set_statemachine = sm.Get ();
++
++ if (!builder_type.Define () || !istate_machine.Define () || set_result == null || builder_factory == null ||
++ set_exception == null || set_statemachine == null || builder_start == null ||
++ !Module.PredefinedTypes.INotifyCompletion.Define ()) {
++ Report.Error (1993, Location,
++ "Cannot find compiler required types for asynchronous functions support. Are you targeting the wrong framework version?");
++ return base.DoDefineMembers ();
++ }
+
+- var bt = builder_type.TypeSpec;
++ bt = builder_type.TypeSpec;
++ }
+
+ //
+ // Inflate generic Task types
+@@ -825,9 +879,26 @@ namespace Mono.CSharp
+ predefined = unsafeVersion ? pm.AsyncVoidMethodBuilderOnCompletedUnsafe : pm.AsyncVoidMethodBuilderOnCompleted;
+ } else if (return_type == Module.PredefinedTypes.Task.TypeSpec) {
+ predefined = unsafeVersion ? pm.AsyncTaskMethodBuilderOnCompletedUnsafe : pm.AsyncTaskMethodBuilderOnCompleted;
+- } else {
++ } else if (return_type.IsGenericTask) {
+ predefined = unsafeVersion ? pm.AsyncTaskMethodBuilderGenericOnCompletedUnsafe : pm.AsyncTaskMethodBuilderGenericOnCompleted;
+ has_task_return_type = true;
++ } else {
++ var parameters = new ParametersImported (
++ new [] {
++ new ParameterData (null, Parameter.Modifier.REF),
++ new ParameterData (null, Parameter.Modifier.REF)
++ },
++ new [] {
++ new TypeParameterSpec (0, null, SpecialConstraint.None, Variance.None, null),
++ new TypeParameterSpec (1, null, SpecialConstraint.None, Variance.None, null)
++ }, false);
++
++ var on_completed_sign = unsafeVersion ?
++ MemberFilter.Method ("AwaitUnsafeOnCompleted", 2, parameters, Compiler.BuiltinTypes.Void) :
++ MemberFilter.Method ("AwaitOnCompleted", 2, parameters, Compiler.BuiltinTypes.Void);
++
++ predefined = new PredefinedMember<MethodSpec> (Module, return_type.MemberDefinition.GetAsyncMethodBuilder (), on_completed_sign);
++ has_task_return_type = return_type.IsGeneric;
+ }
+
+ var on_completed = predefined.Resolve (Location);
+@@ -887,11 +958,14 @@ namespace Mono.CSharp
+ // stateMachine.$builder.Start<{storey-type}>(ref stateMachine);
+ //
+ instance.AddressOf (ec, AddressOp.Store);
+- ec.Emit (OpCodes.Ldflda, builder_field);
++
++ bool struct_builder = builder.MemberType.IsStruct;
++
++ ec.Emit (struct_builder ? OpCodes.Ldflda : OpCodes.Ldfld, builder_field);
+ if (Task != null)
+ ec.Emit (OpCodes.Dup);
+ instance.AddressOf (ec, AddressOp.Store);
+- ec.Emit (OpCodes.Call, builder_start.MakeGenericMethod (Module, instance.Type));
++ ec.Emit (struct_builder ? OpCodes.Call : OpCodes.Callvirt, builder_start.MakeGenericMethod (Module, instance.Type));
+
+ //
+ // Emits return stateMachine.$builder.Task;
+@@ -1029,4 +1103,20 @@ namespace Mono.CSharp
+ EmitAssign (ec, new NullConstant (type, loc), false, false);
+ }
+ }
++
++ static class TypeSpecAsyncExtensions
++ {
++ public static bool IsCustomTaskType (this TypeSpec type)
++ {
++ // LAMESPEC: Arity is not mentioned
++ if (type.Arity > 1)
++ return false;
++
++ var amb = type.MemberDefinition.GetAsyncMethodBuilder ();
++ if (amb == null)
++ return false;
++
++ return amb.Arity == type.Arity;
++ }
++ }
+ }
+diff --git a/mcs/mcs/attribute.cs b/mcs/mcs/attribute.cs
+index 3ff2d68ccb5..83d403118ad 100644
+--- a/mcs/mcs/attribute.cs
++++ b/mcs/mcs/attribute.cs
+@@ -789,6 +789,17 @@ namespace Mono.CSharp {
+ return ((BoolConstant) pos_args[0].Expr).Value;
+ }
+
++ public TypeSpec GetAsyncMethodBuilderValue ()
++ {
++ if (!arg_resolved)
++ Resolve ();
++
++ if (resolve_error)
++ return null;
++
++ return GetArgumentType ();
++ }
++
+ public TypeSpec GetCoClassAttributeValue ()
+ {
+ if (!arg_resolved)
+@@ -1754,9 +1765,11 @@ namespace Mono.CSharp {
+
+ // New in .NET 4.7
+ public readonly PredefinedTupleElementNamesAttribute TupleElementNames;
++ public readonly PredefinedAttribute AsyncMethodBuilder;
+
+ // New in .NET 4.7.1
+ public readonly PredefinedAttribute IsReadOnly;
++ public readonly PredefinedAttribute IsByRefLike;
+
+ //
+ // Optional types which are used as types and for member lookup
+@@ -1837,8 +1850,10 @@ namespace Mono.CSharp {
+ CallerLineNumberAttribute = new PredefinedAttribute (module, "System.Runtime.CompilerServices", "CallerLineNumberAttribute");
+ CallerFilePathAttribute = new PredefinedAttribute (module, "System.Runtime.CompilerServices", "CallerFilePathAttribute");
+
++ AsyncMethodBuilder = new PredefinedAttribute (module, "System.Runtime.CompilerServices", "AsyncMethodBuilderAttribute");
+ TupleElementNames = new PredefinedTupleElementNamesAttribute (module, "System.Runtime.CompilerServices", "TupleElementNamesAttribute");
+ IsReadOnly = new PredefinedAttribute (module, "System.Runtime.CompilerServices", "IsReadOnlyAttribute");
++ IsByRefLike = new PredefinedAttribute (module, "System.Runtime.CompilerServices", "IsByRefLikeAttribute");
+
+ // TODO: Should define only attributes which are used for comparison
+ const System.Reflection.BindingFlags all_fields = System.Reflection.BindingFlags.Public |
+diff --git a/mcs/mcs/class.cs b/mcs/mcs/class.cs
+index 9afb32c6fe5..6b1adc297a3 100644
+--- a/mcs/mcs/class.cs
++++ b/mcs/mcs/class.cs
+@@ -224,6 +224,24 @@ namespace Mono.CSharp
+ }
+ }
+
++ public void CloseContainerEarlyForReflectionEmit ()
++ {
++ if (containers != null) {
++ foreach (TypeContainer tc in containers) {
++ //
++ // SRE requires due to internal checks that any field of enum type is
++ // baked. We close all enum types before closing any other types to
++ // workaround this limitation
++ //
++ if (tc.Kind == MemberKind.Enum) {
++ tc.CloseContainer ();
++ } else {
++ tc.CloseContainerEarlyForReflectionEmit ();
++ }
++ }
++ }
++ }
++
+ public virtual void CreateMetadataName (StringBuilder sb)
+ {
+ if (Parent != null && Parent.MemberName != null)
+@@ -1102,6 +1120,18 @@ namespace Mono.CSharp
+ member.GenerateDocComment (builder);
+ }
+
++ public TypeSpec GetAsyncMethodBuilder ()
++ {
++ if (OptAttributes == null)
++ return null;
++
++ Attribute a = OptAttributes.Search (Module.PredefinedAttributes.AsyncMethodBuilder);
++ if (a == null)
++ return null;
++
++ return a.GetAsyncMethodBuilderValue ();
++ }
++
+ public TypeSpec GetAttributeCoClass ()
+ {
+ if (OptAttributes == null)
+@@ -2171,7 +2201,7 @@ namespace Mono.CSharp
+
+ public override void Emit ()
+ {
+- if (Interfaces != null) {
++ if (Interfaces != null && (ModFlags & Modifiers.PRIVATE) == 0) {
+ foreach (var iface in Interfaces) {
+ if (iface.HasNamedTupleElement) {
+ throw new NotImplementedException ("named tuples for .interfaceimpl");
+@@ -3023,7 +3053,8 @@ namespace Mono.CSharp
+ Modifiers.INTERNAL |
+ Modifiers.UNSAFE |
+ Modifiers.PRIVATE |
+- Modifiers.READONLY;
++ Modifiers.READONLY |
++ Modifiers.REF;
+
+ public Struct (TypeContainer parent, MemberName name, Modifiers mod, Attributes attrs)
+ : base (parent, name, attrs, MemberKind.Struct)
+@@ -3139,6 +3170,9 @@ namespace Mono.CSharp
+ if ((ModFlags & Modifiers.READONLY) != 0)
+ Module.PredefinedAttributes.IsReadOnly.EmitAttribute (TypeBuilder);
+
++ if ((ModFlags & Modifiers.REF) != 0)
++ Module.PredefinedAttributes.IsByRefLike.EmitAttribute (TypeBuilder);
++
+ CheckStructCycles ();
+
+ base.Emit ();
+@@ -3213,6 +3247,10 @@ namespace Mono.CSharp
+ protected override TypeSpec[] ResolveBaseTypes (out FullNamedExpression base_class)
+ {
+ var ifaces = base.ResolveBaseTypes (out base_class);
++ if (ifaces != null && (ModFlags & Modifiers.REF) != 0) {
++ Report.Error (8343, Location, "`{0}': ref structs cannot implement interfaces", GetSignatureForError ());
++ }
++
+ base_type = Compiler.BuiltinTypes.ValueType;
+ return ifaces;
+ }
+@@ -3915,7 +3953,7 @@ namespace Mono.CSharp
+
+ protected void IsTypePermitted ()
+ {
+- if (MemberType.IsSpecialRuntimeType) {
++ if (MemberType.IsSpecialRuntimeType || MemberType.IsByRefLike) {
+ if (Parent is StateMachine) {
+ Report.Error (4012, Location,
+ "Parameters or local variables of type `{0}' cannot be declared in async methods or iterators",
+@@ -3924,6 +3962,19 @@ namespace Mono.CSharp
+ Report.Error (4013, Location,
+ "Local variables of type `{0}' cannot be used inside anonymous methods, lambda expressions or query expressions",
+ MemberType.GetSignatureForError ());
++ } else if (MemberType.IsByRefLike) {
++ if ((ModFlags & (Modifiers.ABSTRACT | Modifiers.EXTERN)) != 0)
++ return;
++
++ if ((ModFlags & Modifiers.AutoProperty) == 0 && this is Property)
++ return;
++
++ if ((ModFlags & Modifiers.STATIC) == 0 && (Parent.ModFlags & Modifiers.REF) != 0)
++ return;
++
++ Report.Error (8345, Location,
++ "Field or auto-implemented property cannot be of type `{0}' unless it is an instance member of a ref struct",
++ MemberType.GetSignatureForError ());
+ } else {
+ Report.Error (610, Location,
+ "Field or property cannot be of type `{0}'", MemberType.GetSignatureForError ());
+diff --git a/mcs/mcs/const.cs b/mcs/mcs/const.cs
+index 046aec24c1b..658f15ec57a 100644
+--- a/mcs/mcs/const.cs
++++ b/mcs/mcs/const.cs
+@@ -206,7 +206,9 @@ namespace Mono.CSharp {
+ c = field.ConvertInitializer (rc, c);
+
+ if (c == null) {
+- if (TypeSpec.IsReferenceType (field.MemberType))
++ if (expr is DefaultLiteralExpression) {
++ // It's handled bellow in New.Constantify
++ } else if (TypeSpec.IsReferenceType (field.MemberType))
+ Error_ConstantCanBeInitializedWithNullOnly (rc, field.MemberType, expr.Location, GetSignatureForError ());
+ else if (!(expr is Constant))
+ Error_ExpressionMustBeConstant (rc, expr.Location, GetSignatureForError ());
+diff --git a/mcs/mcs/convert.cs b/mcs/mcs/convert.cs
+index b11477c1043..ae153fc49e8 100644
+--- a/mcs/mcs/convert.cs
++++ b/mcs/mcs/convert.cs
+@@ -392,6 +392,9 @@ namespace Mono.CSharp {
+ if (!TypeSpec.IsValueType (expr_type))
+ return null;
+
++ if (expr_type.IsByRefLike)
++ return null;
++
+ return expr == null ? EmptyExpression.Null : new BoxedCast (expr, target_type);
+
+ case BuiltinTypeSpec.Type.Enum:
+@@ -816,7 +819,7 @@ namespace Mono.CSharp {
+ if (expr_type == target_type)
+ return true;
+
+- if (expr_type == InternalType.ThrowExpr)
++ if (expr_type == InternalType.ThrowExpr || expr_type == InternalType.DefaultType)
+ return target_type.Kind != MemberKind.InternalCompilerType;
+
+ if (target_type.IsNullableType)
+@@ -1478,6 +1481,10 @@ namespace Mono.CSharp {
+ return target_type.Kind == MemberKind.InternalCompilerType ? null : EmptyCast.Create (expr, target_type);
+ }
+
++ if (expr_type == InternalType.DefaultType) {
++ return new DefaultValueExpression (new TypeExpression (target_type, expr.Location), expr.Location).Resolve (ec);
++ }
++
+ if (target_type.IsNullableType)
+ return ImplicitNulableConversion (ec, expr, target_type);
+
+@@ -1967,7 +1974,7 @@ namespace Mono.CSharp {
+ // From object or dynamic to any reference type or value type (unboxing)
+ //
+ if (source_type.BuiltinType == BuiltinTypeSpec.Type.Object || source_type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
+- if (target_type.IsPointer)
++ if (target_type.IsPointer || target_type.IsByRefLike)
+ return null;
+
+ return
+diff --git a/mcs/mcs/cs-parser.jay b/mcs/mcs/cs-parser.jay
+index 2868d2fd8f6..4d6fcb44c0d 100644
+--- a/mcs/mcs/cs-parser.jay
++++ b/mcs/mcs/cs-parser.jay
+@@ -169,7 +169,8 @@ namespace Mono.CSharp
+ %token CONST
+ %token CONTINUE
+ %token DECIMAL
+-%token DEFAULT
++%token DEFAULT
++%token DEFAULT_VALUE
+ %token DELEGATE
+ %token DO
+ %token DOUBLE
+@@ -336,6 +337,7 @@ namespace Mono.CSharp
+ %token DEFAULT_COLON
+ %token OPEN_BRACKET_EXPR
+ %token OPEN_PARENS_DECONSTRUCT
++%token REF_STRUCT
+
+ // Make the parser go into eval mode parsing (statements and compilation units).
+ %token EVAL_STATEMENT_PARSER
+@@ -863,7 +865,7 @@ attribute_arguments
+ }
+
+ Arguments args = ((Arguments) o [0]);
+- if (args.Count > 0 && !($3 is NamedArgument) && args [args.Count - 1] is NamedArgument)
++ if (lang_version < LanguageVersion.V_7_2 && args.Count > 0 && !($3 is NamedArgument) && args [args.Count - 1] is NamedArgument)
+ Error_NamedArgumentExpected ((NamedArgument) args [args.Count - 1]);
+
+ args.Add ((Argument) $3);
+@@ -1015,17 +1017,34 @@ primary_constructor_body
+ }
+ ;
+
++struct_keyword
++ : STRUCT
++ {
++ $$ = null;
++ }
++ | REF_STRUCT
++ {
++ if (lang_version < LanguageVersion.V_7_2) {
++ FeatureIsNotAvailable (GetLocation ($1), "ref structs");
++ }
++
++ $$ = this;
++ }
++ ;
++
+ struct_declaration
+ : opt_attributes
+ opt_modifiers
+ opt_partial
+- STRUCT
++ struct_keyword
+ type_declaration_name
+ {
+ var mods = (Modifiers) $2;
+ if ((mods & Modifiers.READONLY) != 0 && lang_version < LanguageVersion.V_7_2) {
+ FeatureIsNotAvailable (GetLocation ($4), "readonly structs");
+ }
++ if ($4 != null)
++ mods |= Modifiers.REF;
+
+ lexer.ConstraintsParsing = true;
+ valid_param_mod = ParameterModifierType.PrimaryConstructor;
+@@ -1071,7 +1090,7 @@ struct_declaration
+ }
+ $$ = pop_current_class ();
+ }
+- | opt_attributes opt_modifiers opt_partial STRUCT error
++ | opt_attributes opt_modifiers opt_partial struct_keyword error
+ {
+ Error_SyntaxError (yyToken);
+ }
+@@ -1384,6 +1403,18 @@ ref_member_type
+
+ $$ = new ReferenceTypeExpr ((FullNamedExpression) $3, GetLocation ($1));
+ }
++ | REF READONLY
++ {
++ lexer.parsing_generic_declaration = true;
++ }
++ type
++ {
++ if (lang_version < LanguageVersion.V_7_2) {
++ FeatureIsNotAvailable (GetLocation ($2), "readonly references");
++ }
++
++ $$ = new ReferenceTypeExpr ((FullNamedExpression) $4, true, GetLocation ($1));
++ }
+ ;
+
+ method_header
+@@ -3448,6 +3479,7 @@ primary_expression
+ | anonymous_method_expression
+ | undocumented_expressions
+ | interpolated_string
++ | default_literal
+ ;
+
+ type_name_expression
+@@ -3824,7 +3856,7 @@ argument_list
+ | argument_list COMMA argument
+ {
+ Arguments list = (Arguments) $1;
+- if (list [list.Count - 1] is NamedArgument)
++ if (lang_version < LanguageVersion.V_7_2 && list [list.Count - 1] is NamedArgument)
+ Error_NamedArgumentExpected ((NamedArgument) list [list.Count - 1]);
+
+ list.Add ((Argument) $3);
+@@ -3969,7 +4001,7 @@ expression_list_arguments
+ | expression_list_arguments COMMA expression_list_argument
+ {
+ Arguments args = (Arguments) $1;
+- if (args [args.Count - 1] is NamedArgument && !($3 is NamedArgument))
++ if (lang_version < LanguageVersion.V_7_2 && args [args.Count - 1] is NamedArgument && !($3 is NamedArgument))
+ Error_NamedArgumentExpected ((NamedArgument) args [args.Count - 1]);
+
+ args.Add ((Argument) $3);
+@@ -4386,7 +4418,7 @@ anonymous_method_signature
+ ;
+
+ default_value_expression
+- : DEFAULT open_parens_any type CLOSE_PARENS
++ : DEFAULT_VALUE open_parens_any type CLOSE_PARENS
+ {
+ if (lang_version < LanguageVersion.ISO_2)
+ FeatureIsNotAvailable (GetLocation ($1), "default value expression");
+@@ -4396,6 +4428,16 @@ default_value_expression
+ }
+ ;
+
++default_literal
++ : DEFAULT
++ {
++ if (lang_version < LanguageVersion.V_7_1)
++ FeatureIsNotAvailable (GetLocation ($1), "default literal");
++
++ $$ = new DefaultLiteralExpression (GetLocation ($1));
++ }
++ ;
++
+ unary_expression
+ : primary_expression
+ | BANG prefixed_unary_expression
+@@ -4750,7 +4792,7 @@ pattern_list
+ | pattern_list COMMA pattern_argument
+ {
+ Arguments args = (Arguments) $1;
+- if (args [args.Count - 1] is NamedArgument && !($3 is NamedArgument))
++ if (lang_version < LanguageVersion.V_7_2 && args [args.Count - 1] is NamedArgument && !($3 is NamedArgument))
+ Error_NamedArgumentExpected ((NamedArgument) args [args.Count - 1]);
+
+ args.Add ((Argument) $3);
+@@ -5067,17 +5109,25 @@ assignment_expression
+ $$ = new CompoundAssign (Binary.Operator.ExclusiveOr, (Expression) $1, (Expression) $3);
+ lbag.AddLocation ($$, GetLocation ($2));
+ }
+- | OPEN_PARENS_DECONSTRUCT deconstruct_exprs CLOSE_PARENS ASSIGN expression
++ | OPEN_PARENS_DECONSTRUCT deconstruct_assignment CLOSE_PARENS ASSIGN expression
+ {
+ if (lang_version < LanguageVersion.V_7)
+ FeatureIsNotAvailable (GetLocation ($1), "tuples");
+
+- var exprs = (List<Expression>) $2;
++ var exprs = (List<Expression>) $2;
++ $$ = new TupleDeconstruct (exprs, (Expression) $5, GetLocation ($4));
++ }
++ | OPEN_PARENS_DECONSTRUCT deconstruct_declaration CLOSE_PARENS ASSIGN expression
++ {
++ if (lang_version < LanguageVersion.V_7)
++ FeatureIsNotAvailable (GetLocation ($1), "tuples");
++
++ var exprs = (List<BlockVariable>) $2;
+ $$ = new TupleDeconstruct (exprs, (Expression) $5, GetLocation ($4));
+ }
+ ;
+
+-deconstruct_exprs
++deconstruct_assignment
+ : expression COMMA expression
+ {
+ $$ = new List<Expression> () {
+@@ -5085,7 +5135,7 @@ deconstruct_exprs
+ (Expression) $3
+ };
+ }
+- | deconstruct_exprs COMMA expression
++ | deconstruct_assignment COMMA expression
+ {
+ var src = (List<Expression>) $1;
+ src.Add ((Expression) $3);
+@@ -5093,6 +5143,43 @@ deconstruct_exprs
+ }
+ ;
+
++deconstruct_declaration
++ : variable_type identifier_inside_body
++ {
++ var lt = (LocatedToken) $2;
++ var li = new LocalVariable (current_block, lt.Value, lt.Location);
++ current_block.AddLocalName (li);
++ $$ = new List<BlockVariable> (2) {
++ new BlockVariable ((FullNamedExpression) $1, li)
++ };
++ }
++ | deconstruct_declaration COMMA variable_type identifier_inside_body
++ {
++ var lt = (LocatedToken) $4;
++ var li = new LocalVariable (current_block, lt.Value, lt.Location);
++ current_block.AddLocalName (li);
++
++ var src = (List<BlockVariable>) $1;
++ src.Add (new BlockVariable ((FullNamedExpression) $3, li));
++ $$ = src;
++ }
++ | deconstruct_declaration COMMA identifier_inside_body
++ {
++ var lt = (LocatedToken) $3;
++ var li = new LocalVariable (current_block, lt.Value, lt.Location);
++
++ if (lt.Value != "_") {
++ report.Error (8184, lt.Location, "A deconstruction cannot mix declarations and expressions on the left-hand-side");
++ } else {
++ li.Type = InternalType.Discard;
++ }
++
++ var src = (List<BlockVariable>) $1;
++ src.Add (new BlockVariable (new TypeExpression (li.Type, lt.Location), li));
++ $$ = src;
++ }
++ ;
++
+ lambda_parameter_list
+ : lambda_parameter
+ {
+@@ -6008,6 +6095,28 @@ block_variable_declaration
+ lbag.AddLocation ($$, GetLocation ($7));
+ }
+ }
++ | REF READONLY variable_type identifier_inside_body
++ {
++ if (lang_version < LanguageVersion.V_7_2) {
++ FeatureIsNotAvailable (GetLocation ($2), "readonly references");
++ }
++
++ var lt = (LocatedToken) $4;
++ var li = new LocalVariable (current_block, lt.Value, LocalVariable.Flags.ByRef | LocalVariable.Flags.ReadonlyMask, lt.Location);
++ current_block.AddLocalName (li);
++ current_variable = new BlockVariable ((FullNamedExpression) $3, li);
++ }
++ opt_local_variable_initializer opt_variable_declarators SEMICOLON
++ {
++ $$ = current_variable;
++ current_variable = null;
++ if ($6 != null) {
++ lbag.AddLocation ($$, PopLocation (), GetLocation ($8));
++ } else {
++ report.Error (8174, GetLocation ($3), "A declaration of a by-reference variable must have an initializer");
++ lbag.AddLocation ($$, GetLocation ($8));
++ }
++ }
+ ;
+
+ opt_local_variable_initializer
+@@ -7731,7 +7840,7 @@ void Warning_EmptyStatement (Location loc)
+
+ void Error_NamedArgumentExpected (NamedArgument a)
+ {
+- report.Error (1738, a.Location, "Named arguments must appear after the positional arguments");
++ report.Error (1738, a.Location, "Named arguments must appear after the positional arguments when using language version older than 7.2");
+ }
+
+ void Error_MissingInitializer (Location loc)
+@@ -8255,6 +8364,7 @@ static string GetTokenName (int token)
+ case Token.CONTINUE:
+ return "continue";
+ case Token.DEFAULT:
++ case Token.DEFAULT_VALUE:
+ return "default";
+ case Token.DELEGATE:
+ return "delegate";
+@@ -8334,6 +8444,7 @@ static string GetTokenName (int token)
+ case Token.STATIC:
+ return "static";
+ case Token.STRUCT:
++ case Token.REF_STRUCT:
+ return "struct";
+ case Token.SWITCH:
+ return "switch";
+diff --git a/mcs/mcs/cs-tokenizer.cs b/mcs/mcs/cs-tokenizer.cs
+index d6d00d31400..37edb5c1224 100644
+--- a/mcs/mcs/cs-tokenizer.cs
++++ b/mcs/mcs/cs-tokenizer.cs
+@@ -716,9 +716,18 @@ namespace Mono.CSharp
+ res = Token.EXTERN_ALIAS;
+ break;
+ case Token.DEFAULT:
+- if (peek_token () == Token.COLON) {
+- token ();
+- res = Token.DEFAULT_COLON;
++ switch (peek_token ()) {
++ case Token.COLON:
++ // Special case: foo == null ? default : 1;
++ if (current_token != Token.INTERR) {
++ token ();
++ res = Token.DEFAULT_COLON;
++ }
++ break;
++ case Token.OPEN_PARENS:
++ case Token.OPEN_PARENS_CAST:
++ res = Token.DEFAULT_VALUE;
++ break;
+ }
+ break;
+ case Token.WHEN:
+@@ -812,10 +821,12 @@ namespace Mono.CSharp
+ PushPosition ();
+
+ next_token = token ();
+- bool ok = (next_token == Token.CLASS) ||
+- (next_token == Token.STRUCT) ||
+- (next_token == Token.INTERFACE) ||
+- (next_token == Token.VOID);
++ bool ok =
++ next_token == Token.CLASS ||
++ next_token == Token.STRUCT ||
++ next_token == Token.INTERFACE ||
++ next_token == Token.VOID ||
++ next_token == Token.REF_STRUCT;
+
+ PopPosition ();
+
+@@ -903,6 +914,12 @@ namespace Mono.CSharp
+ break;
+ }
+
++ break;
++ case Token.REF:
++ if (peek_token () == Token.STRUCT) {
++ token ();
++ res = Token.REF_STRUCT;
++ }
+ break;
+ }
+
+@@ -1094,6 +1111,7 @@ namespace Mono.CSharp
+ case Token.UNCHECKED:
+ case Token.UNSAFE:
+ case Token.DEFAULT:
++ case Token.DEFAULT_VALUE:
+ case Token.AWAIT:
+
+ //
+@@ -1273,14 +1291,21 @@ namespace Mono.CSharp
+
+ return false;
+ case Token.OPEN_PARENS:
+- if (!parsing_generic_declaration)
+- return false;
+-
++ int parens_count = 1;
+ while (true) {
+ switch (token ()) {
+ case Token.COMMA:
+ // tuple declaration after <
+- return true;
++ if (parens_count == 1)
++ return true;
++ continue;
++ case Token.OPEN_PARENS:
++ ++parens_count;
++ continue;
++ case Token.CLOSE_PARENS:
++ if (--parens_count <= 0)
++ return false;
++ continue;
+ case Token.OP_GENERICS_GT:
+ case Token.EOF:
+ return false;
+@@ -1380,6 +1405,7 @@ namespace Mono.CSharp
+ case Token.NEW:
+ case Token.INTERPOLATED_STRING:
+ case Token.THROW:
++ case Token.DEFAULT_COLON:
+ next_token = Token.INTERR;
+ break;
+
+@@ -3502,6 +3528,7 @@ namespace Mono.CSharp
+ case Token.SWITCH:
+ case Token.USING:
+ case Token.DEFAULT:
++ case Token.DEFAULT_VALUE:
+ case Token.DELEGATE:
+ case Token.OP_GENERICS_GT:
+ case Token.REFVALUE:
+@@ -3963,26 +3990,29 @@ namespace Mono.CSharp
+ {
+ int d;
+
+- // Save current position and parse next token.
+- PushPosition ();
+- int generic_dimension = 0;
+- if (parse_less_than (ref generic_dimension)) {
+- if (parsing_generic_declaration && (parsing_generic_declaration_doc || token () != Token.DOT)) {
+- d = Token.OP_GENERICS_LT_DECL;
+- } else {
+- if (generic_dimension > 0) {
+- val = generic_dimension;
+- DiscardPosition ();
+- return Token.GENERIC_DIMENSION;
+- }
++ if (current_token != Token.OPERATOR) {
++ // Save current position and parse next token.
++ PushPosition ();
++ int generic_dimension = 0;
++ if (parse_less_than (ref generic_dimension)) {
++ if (parsing_generic_declaration && (parsing_generic_declaration_doc || token () != Token.DOT)) {
++ d = Token.OP_GENERICS_LT_DECL;
++ } else {
++ if (generic_dimension > 0) {
++ val = generic_dimension;
++ DiscardPosition ();
++ return Token.GENERIC_DIMENSION;
++ }
+
+- d = Token.OP_GENERICS_LT;
++ d = Token.OP_GENERICS_LT;
++ }
++ PopPosition ();
++ return d;
+ }
++
+ PopPosition ();
+- return d;
+ }
+
+- PopPosition ();
+ parsing_generic_less_than = 0;
+
+ d = peek_char ();
+diff --git a/mcs/mcs/delegate.cs b/mcs/mcs/delegate.cs
+index 80eb7e265f1..52cee8f3455 100644
+--- a/mcs/mcs/delegate.cs
++++ b/mcs/mcs/delegate.cs
+@@ -188,8 +188,8 @@ namespace Mono.CSharp {
+
+ CheckProtectedModifier ();
+
+- if (Compiler.Settings.StdLib && ret_type.IsSpecialRuntimeType) {
+- Method.Error1599 (Location, ret_type, Report);
++ if (ret_type.IsSpecialRuntimeType && Compiler.Settings.StdLib) {
++ Method.Error_ReturnTypeCantBeRefAny (Location, ret_type, Report);
+ return false;
+ }
+
+@@ -338,6 +338,8 @@ namespace Mono.CSharp {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder);
+ } else if (rtype.HasDynamicElement) {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder, rtype, Location);
++ } else if (rtype is ReadOnlyReferenceContainer) {
++ Module.PredefinedAttributes.IsReadOnly.EmitAttribute (CreateReturnBuilder ().Builder);
+ }
+
+ if (rtype.HasNamedTupleElement) {
+@@ -603,8 +605,14 @@ namespace Mono.CSharp {
+ }
+
+ var expr = method_group.InstanceExpression;
+- if (expr != null && (expr.Type.IsGenericParameter || !TypeSpec.IsReferenceType (expr.Type)))
++ if (expr != null && (expr.Type.IsGenericParameter || !TypeSpec.IsReferenceType (expr.Type))) {
++ if (expr.Type.IsByRefLike || expr.Type.IsSpecialRuntimeType) {
++ // CSC: Should be better error code
++ Error_ConversionFailed (ec, delegate_method, null);
++ }
++
+ method_group.InstanceExpression = new BoxedCast (expr, ec.BuiltinTypes.Object);
++ }
+
+ eclass = ExprClass.Value;
+ return this;
+diff --git a/mcs/mcs/dynamic.cs b/mcs/mcs/dynamic.cs
+index fd4662b2fed..f8314b2f3cd 100644
+--- a/mcs/mcs/dynamic.cs
++++ b/mcs/mcs/dynamic.cs
+@@ -279,11 +279,19 @@ namespace Mono.CSharp
+
+ protected bool DoResolveCore (ResolveContext rc)
+ {
++ int i = 0;
+ foreach (var arg in arguments) {
+ if (arg.Type == InternalType.VarOutType) {
+ // Should be special error message about dynamic dispatch
+ rc.Report.Error (8197, arg.Expr.Location, "Cannot infer the type of implicitly-typed out variable `{0}'", ((DeclarationExpression) arg.Expr).Variable.Name);
++ } else if (arg.Type == InternalType.DefaultType) {
++ rc.Report.Error (8311, arg.Expr.Location, "Cannot use a default literal as an argument to a dynamically dispatched operation");
+ }
++
++ // Forced limitation because Microsoft.CSharp needs to catch up
++ if (i > 0 && arguments [i - 1] is NamedArgument && !(arguments [i] is NamedArgument))
++ rc.Report.Error (8324, loc, "Named argument specifications must appear after all fixed arguments have been specified in a dynamic invocation");
++ ++i;
+ }
+
+ if (rc.CurrentTypeParameters != null && rc.CurrentTypeParameters[0].IsMethodTypeParameter)
+diff --git a/mcs/mcs/ecore.cs b/mcs/mcs/ecore.cs
+index 34ff9a30dab..20ee9e73b19 100644
+--- a/mcs/mcs/ecore.cs
++++ b/mcs/mcs/ecore.cs
+@@ -255,7 +255,7 @@ namespace Mono.CSharp {
+
+ public void Error_ExpressionMustBeConstant (ResolveContext rc, Location loc, string e_name)
+ {
+- rc.Report.Error (133, loc, "The expression being assigned to `{0}' must be constant", e_name);
++ rc.Report.Error (133, loc, "The expression being assigned to `{0}' must be a constant or default value", e_name);
+ }
+
+ public void Error_ConstantCanBeInitializedWithNullOnly (ResolveContext rc, TypeSpec type, Location loc, string name)
+@@ -2957,6 +2957,13 @@ namespace Mono.CSharp {
+ if ((restrictions & MemberLookupRestrictions.NameOfExcluded) == 0 && Name == "nameof")
+ return new NameOf (this);
+
++ if ((restrictions & MemberLookupRestrictions.ReadAccess) == 0 && Name == "_") {
++ if (rc.Module.Compiler.Settings.Version < LanguageVersion.V_7)
++ rc.Report.FeatureIsNotAvailable (rc.Module.Compiler, loc, "discards");
++
++ return new Discard (loc).Resolve (rc);
++ }
++
+ if (errorMode) {
+ if (variable_found) {
+ rc.Report.Error (841, loc, "A local variable `{0}' cannot be used before it is declared", Name);
+@@ -4029,6 +4036,13 @@ namespace Mono.CSharp {
+ return Methods.First ().GetSignatureForError ();
+ }
+
++ static MethodSpec CandidateDevirtualization (TypeSpec type, MethodSpec method)
++ {
++ // Assumes no generics get involved
++ var filter = new MemberFilter (method.Name, method.Arity, MemberKind.Method, method.Parameters, null);
++ return MemberCache.FindMember (type, filter, BindingRestriction.InstanceOnly | BindingRestriction.OverrideOnly | BindingRestriction.DeclaredOnly) as MethodSpec;
++ }
++
+ public override Expression CreateExpressionTree (ResolveContext ec)
+ {
+ if (best_candidate == null) {
+@@ -4177,6 +4191,22 @@ namespace Mono.CSharp {
+ }
+
+ InstanceExpression.Resolve (ec, ResolveFlags.VariableOrValue | ResolveFlags.MethodGroup | ResolveFlags.Type);
++
++ var expr_type = InstanceExpression.Type;
++ if ((expr_type.IsByRefLike || expr_type.IsSpecialRuntimeType) && best_candidate.DeclaringType != expr_type) {
++ MethodSpec devirt = null;
++ if ((best_candidate.Modifiers & (Modifiers.VIRTUAL | Modifiers.ABSTRACT | Modifiers.OVERRIDE)) != 0) {
++ devirt = CandidateDevirtualization (expr_type, best_candidate);
++ }
++
++ if (devirt == null) {
++ // CSC: Should be better error message
++ ec.Report.Error (29, InstanceExpression.Location, "Cannot implicitly convert type `{0}' to `{1}'",
++ InstanceExpression.Type.GetSignatureForError (), best_candidate.DeclaringType.GetSignatureForError ());
++ } else {
++ best_candidate = devirt;
++ }
++ }
+ }
+ }
+
+@@ -5419,7 +5449,7 @@ namespace Mono.CSharp {
+ }
+
+ if (arg_type != parameter) {
+- if (arg_type == InternalType.VarOutType)
++ if (arg_type == InternalType.VarOutType || arg_type == InternalType.Discard)
+ return 0;
+
+ var ref_arg_type = arg_type as ReferenceContainer;
+@@ -6028,6 +6058,11 @@ namespace Mono.CSharp {
+ continue;
+ }
+
++ if (arg_type == InternalType.Discard) {
++ a.Expr.Type = pt;
++ continue;
++ }
++
+ var ref_arg_type = arg_type as ReferenceContainer;
+ if (ref_arg_type != null) {
+ if (ref_arg_type.Element != pt)
+@@ -6061,9 +6096,15 @@ namespace Mono.CSharp {
+ else
+ ec.Report.SymbolRelatedToPreviousError (member);
+
+- ec.Report.Error (1744, na.Location,
+- "Named argument `{0}' cannot be used for a parameter which has positional argument specified",
+- na.Name);
++ if (name_index > a_idx) {
++ ec.Report.Error (8323, na.Location,
++ "Named argument `{0}' is used out of position but is followed by positional argument",
++ na.Name);
++ } else {
++ ec.Report.Error (1744, na.Location,
++ "Named argument `{0}' cannot be used for a parameter which has positional argument specified",
++ na.Name);
++ }
+ }
+ }
+
+@@ -7350,6 +7391,9 @@ namespace Mono.CSharp {
+ if (!ResolveGetter (ec))
+ return null;
+
++ if (type.Kind == MemberKind.ByRef)
++ return ByRefDereference.Create (this).Resolve (ec);
++
+ return this;
+ }
+
+@@ -7359,12 +7403,11 @@ namespace Mono.CSharp {
+ Error_NullPropagatingLValue (rc);
+
+ if (right_side == EmptyExpression.OutAccess) {
+- if (best_candidate?.MemberType.Kind == MemberKind.ByRef) {
+- if (Arguments?.ContainsEmitWithAwait () == true) {
+- rc.Report.Error (8178, loc, "`await' cannot be used in an expression containing a call to `{0}' because it returns by reference",
+- GetSignatureForError ());
+- }
++ if (OverloadResolve (rc, null) == null)
++ return null;
+
++ if (best_candidate?.MemberType.Kind == MemberKind.ByRef) {
++ getter = CandidateToBaseOverride (rc, best_candidate.Get);
+ return this;
+ }
+
+@@ -7396,7 +7439,7 @@ namespace Mono.CSharp {
+
+ if (best_candidate.MemberType.Kind == MemberKind.ByRef) {
+ getter = CandidateToBaseOverride (rc, best_candidate.Get);
+- return ByRefDereference.Create(this).Resolve(rc);
++ return ByRefDereference.Create (this).Resolve (rc);
+ }
+
+ rc.Report.Error (200, loc, "Property or indexer `{0}' cannot be assigned to (it is read-only)",
+diff --git a/mcs/mcs/eval.cs b/mcs/mcs/eval.cs
+index 60e0c6d64a0..075697bb1df 100644
+--- a/mcs/mcs/eval.cs
++++ b/mcs/mcs/eval.cs
+@@ -788,6 +788,7 @@ namespace Mono.CSharp
+ return null;
+ }
+
++ module.CloseContainerEarlyForReflectionEmit ();
+ module.CloseContainer ();
+ if (host != null)
+ host.CloseContainer ();
+diff --git a/mcs/mcs/expression.cs b/mcs/mcs/expression.cs
+index 732ee3ee934..518ccc8ef43 100644
+--- a/mcs/mcs/expression.cs
++++ b/mcs/mcs/expression.cs
+@@ -1220,6 +1220,7 @@ namespace Mono.CSharp
+ expr = expr.ResolveLValue (ec, expr);
+ } else {
+ ec.Report.Error (1059, loc, "The operand of an increment or decrement operator must be a variable, property or indexer");
++ return null;
+ }
+
+ //
+@@ -1477,6 +1478,11 @@ namespace Mono.CSharp
+ return null;
+ }
+
++ if (expr.Type == InternalType.DefaultType) {
++ Error_OperatorCannotBeApplied (rc, loc, OperatorName, expr.Type);
++ return null;
++ }
++
+ return this;
+ }
+
+@@ -4304,9 +4310,32 @@ namespace Mono.CSharp
+ CheckOutOfRangeComparison (ec, rc, left.Type);
+ }
+
+- if (left.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic || right.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
++ var ltype = left.Type;
++ var rtype = right.Type;
++ if (ltype.BuiltinType == BuiltinTypeSpec.Type.Dynamic || rtype.BuiltinType == BuiltinTypeSpec.Type.Dynamic)
+ return DoResolveDynamic (ec);
+
++ //
++ // Only default with == and != is explicitly allowed
++ //
++ if (ltype == InternalType.DefaultType || rtype == InternalType.DefaultType) {
++ if ((Oper & Operator.EqualityMask) == 0) {
++ ec.Report.Error (8310, loc, "Operator `{0}' cannot be applied to operand `default'", OperName (Oper));
++ return null;
++ }
++
++ if (ltype == rtype) {
++ ec.Report.Error (8315, loc, "Operator `{0}' is ambiguous on operands `default' and `default'", OperName (Oper));
++ return null;
++ }
++
++ if (rtype == InternalType.DefaultType) {
++ right = new DefaultValueExpression (new TypeExpression (ltype, right.Location), right.Location).Resolve (ec);
++ } else {
++ left = new DefaultValueExpression (new TypeExpression (rtype, left.Location), left.Location).Resolve (ec);
++ }
++ }
++
+ return DoResolveCore (ec, left, right);
+ }
+
+@@ -6744,10 +6773,14 @@ namespace Mono.CSharp
+ ec.Report.Error (1764, loc,
+ "Cannot use fixed variable `{0}' inside an anonymous method, lambda expression or query expression",
+ GetSignatureForError ());
+- } else if (local_info.IsByRef) {
+- ec.Report.Error (8175, loc,
+- "Cannot use by-reference variable `{0}' inside an anonymous method, lambda expression, or query expression",
+- GetSignatureForError ());
++ } else if (local_info.IsByRef || local_info.Type.IsByRefLike) {
++ if (ec.CurrentAnonymousMethod is StateMachineInitializer) {
++ // It's reported later as 4012/4013
++ } else {
++ ec.Report.Error (8175, loc,
++ "Cannot use by-reference variable `{0}' inside an anonymous method, lambda expression, or query expression",
++ GetSignatureForError ());
++ }
+ }
+
+ if (ec.IsVariableCapturingRequired) {
+@@ -6783,7 +6816,9 @@ namespace Mono.CSharp
+ local_info.SetIsUsed ();
+
+ if (local_info.IsReadonly && !ec.HasAny (ResolveContext.Options.FieldInitializerScope | ResolveContext.Options.UsingInitializerScope)) {
+- if (rhs == EmptyExpression.LValueMemberAccess) {
++ if (local_info.IsByRef) {
++ // OK because it cannot be reassigned
++ } else if (rhs == EmptyExpression.LValueMemberAccess) {
+ // CS1654 already reported
+ } else {
+ int code;
+@@ -7175,8 +7210,7 @@ namespace Mono.CSharp
+ {
+ var sn = expr as SimpleName;
+ if (sn != null && sn.Name == "var" && sn.Arity == 0 && arguments?.Count > 1) {
+- var targets = new List<Expression> (arguments.Count);
+- var variables = new List<LocalVariable> (arguments.Count);
++ var variables = new List<BlockVariable> (arguments.Count);
+ foreach (var arg in arguments) {
+ var arg_sn = arg.Expr as SimpleName;
+ if (arg_sn == null || arg_sn.Arity != 0) {
+@@ -7186,12 +7220,10 @@ namespace Mono.CSharp
+
+ var lv = new LocalVariable (rc.CurrentBlock, arg_sn.Name, arg.Expr.Location);
+ rc.CurrentBlock.AddLocalName (lv);
+- variables.Add (lv);
+-
+- targets.Add (new LocalVariableReference (lv, arg_sn.Location));
++ variables.Add (new BlockVariable (new VarExpr (lv.Location), lv));
+ }
+
+- var res = new TupleDeconstruct (targets, variables, right_side, loc);
++ var res = new TupleDeconstruct (variables, right_side, loc);
+ return res.Resolve (rc);
+ }
+
+@@ -7306,15 +7338,8 @@ namespace Mono.CSharp
+
+ eclass = ExprClass.Value;
+
+- if (type.Kind == MemberKind.ByRef) {
+- if (rhs == null && arguments?.ContainsEmitWithAwait () == true) {
+- ec.Report.Error (8178, loc, "`await' cannot be used in an expression containing a call to `{0}' because it returns by reference",
+- GetSignatureForError ());
+- }
+-
+- if (rhs != EmptyExpression.OutAccess)
+- return ByRefDereference.Create (this).Resolve (ec);
+- }
++ if (type.Kind == MemberKind.ByRef && rhs != EmptyExpression.OutAccess)
++ return ByRefDereference.Create (this).Resolve (ec);
+
+ return this;
+ }
+@@ -9034,7 +9059,7 @@ namespace Mono.CSharp
+ if (eclass == ExprClass.Unresolved)
+ ResolveBase (ec);
+
+- if (type.IsClass || type.IsReadOnly) {
++ if (type.IsClass || (type.IsReadOnly && !ec.HasSet (ResolveContext.Options.ConstructorScope))) {
+ if (right_side == EmptyExpression.UnaryAddress)
+ ec.Report.Error (459, loc, "Cannot take the address of `this' because it is read-only");
+ else if (right_side == EmptyExpression.OutAccess)
+@@ -9908,7 +9933,7 @@ namespace Mono.CSharp
+ public static bool IsValidDotExpression (TypeSpec type)
+ {
+ const MemberKind dot_kinds = MemberKind.Class | MemberKind.Struct | MemberKind.Delegate | MemberKind.Enum |
+- MemberKind.Interface | MemberKind.TypeParameter | MemberKind.ArrayType;
++ MemberKind.Interface | MemberKind.TypeParameter | MemberKind.ArrayType | MemberKind.ByRef;
+
+ return (type.Kind & dot_kinds) != 0 || type.BuiltinType == BuiltinTypeSpec.Type.Dynamic;
+ }
+@@ -11614,7 +11639,7 @@ namespace Mono.CSharp
+ }
+
+ if (single_spec != null && single_spec.Dimension > 0) {
+- if (type.IsSpecialRuntimeType) {
++ if (type.IsSpecialRuntimeType || type.IsByRefLike) {
+ ec.Module.Compiler.Report.Error (611, loc, "Array elements cannot be of type `{0}'", type.GetSignatureForError ());
+ } else if (type.IsStatic) {
+ ec.Module.Compiler.Report.SymbolRelatedToPreviousError (type);
+@@ -11650,6 +11675,13 @@ namespace Mono.CSharp
+ class ReferenceTypeExpr : TypeExpr
+ {
+ FullNamedExpression element;
++ readonly bool readOnly;
++
++ public ReferenceTypeExpr (FullNamedExpression element, bool readOnly, Location loc)
++ : this (element, loc)
++ {
++ this.readOnly = readOnly;
++ }
+
+ public ReferenceTypeExpr (FullNamedExpression element, Location loc)
+ {
+@@ -11664,14 +11696,17 @@ namespace Mono.CSharp
+ return null;
+
+ eclass = ExprClass.Type;
+- type = ReferenceContainer.MakeType (mc.Module, type);
++ type = readOnly ?
++ ReadOnlyReferenceContainer.MakeType (mc.Module, type) :
++ ReferenceContainer.MakeType (mc.Module, type);
+
+ return type;
+ }
+
+ public override string GetSignatureForError ()
+ {
+- return "ref " + element.GetSignatureForError ();
++ var prefix = readOnly ? "ref " : "ref readonly ";
++ return prefix + element.GetSignatureForError ();
+ }
+
+ public override object Accept (StructuralVisitor visitor)
+@@ -11783,6 +11818,7 @@ namespace Mono.CSharp
+ TypeSpec otype;
+ Expression texpr;
+ Expression count;
++ MethodSpec ctor;
+
+ public StackAlloc (Expression type, Expression count, Location l)
+ {
+@@ -11852,6 +11888,11 @@ namespace Mono.CSharp
+ int size = BuiltinTypeSpec.GetSize (otype);
+
+ count.Emit (ec);
++ bool count_on_stack = false;
++ if (ctor != null && !ExpressionAnalyzer.IsInexpensiveLoad (count)) {
++ ec.Emit (OpCodes.Dup);
++ count_on_stack = true;
++ }
+
+ if (size == 0)
+ ec.Emit (OpCodes.Sizeof, otype);
+@@ -11860,6 +11901,19 @@ namespace Mono.CSharp
+
+ ec.Emit (OpCodes.Mul_Ovf_Un);
+ ec.Emit (OpCodes.Localloc);
++
++ if (ctor != null) {
++ if (!count_on_stack)
++ count.Emit (ec);
++ ec.Emit (OpCodes.Newobj, ctor);
++ }
++ }
++
++ public override void Error_ValueCannotBeConverted (ResolveContext rc, TypeSpec target, bool expl)
++ {
++ var etype = ((PointerContainer)type).Element;
++ rc.Report.Error (8346, loc, "Cannot convert a stackalloc expression of type `{0}' to type `{1}'",
++ etype.GetSignatureForError (), target.GetSignatureForError ());
+ }
+
+ protected override void CloneTo (CloneContext clonectx, Expression t)
+@@ -11873,6 +11927,16 @@ namespace Mono.CSharp
+ {
+ return visitor.Visit (this);
+ }
++
++ public bool ResolveSpanConversion (ResolveContext rc, TypeSpec spanType)
++ {
++ ctor = MemberCache.FindMember (spanType, MemberFilter.Constructor (ParametersCompiled.CreateFullyResolved (PointerContainer.MakeType (rc.Module, rc.Module.Compiler.BuiltinTypes.Void), rc.Module.Compiler.BuiltinTypes.Int)), BindingRestriction.DeclaredOnly) as MethodSpec;
++ if (ctor == null)
++ return false;
++
++ this.type = spanType;
++ return true;
++ }
+ }
+
+ //
+@@ -13093,6 +13157,12 @@ namespace Mono.CSharp
+ expr.Emit (ec);
+ }
+
++ public override Expression CreateExpressionTree (ResolveContext rc)
++ {
++ rc.Report.Error (8153, Location, "An expression tree lambda cannot contain a call to a method, property, or indexer that returns by reference");
++ return null;
++ }
++
+ public void Emit (EmitContext ec, bool leave_copy)
+ {
+ Emit (ec);
+@@ -13133,6 +13203,11 @@ namespace Mono.CSharp
+
+ public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
+ {
++ if (expr.ContainsEmitWithAwait ()) {
++ rc.Report.Error (8178, loc, "`await' cannot be used in an expression containing a call to `{0}' because it returns by reference",
++ expr.GetSignatureForError ());
++ }
++
+ return DoResolve (rc);
+ }
+
+@@ -13149,4 +13224,98 @@ namespace Mono.CSharp
+ return visitor.Visit (this);
+ }
+ }
++
++ class DefaultLiteralExpression : Expression
++ {
++ public DefaultLiteralExpression (Location loc)
++ {
++ this.loc = loc;
++ }
++
++ public override Expression CreateExpressionTree (ResolveContext ec)
++ {
++ throw new NotImplementedException ();
++ }
++
++ protected override Expression DoResolve (ResolveContext rc)
++ {
++ type = InternalType.DefaultType;
++ eclass = ExprClass.Value;
++ return this;
++ }
++
++ public override void Emit (EmitContext ec)
++ {
++ throw new NotSupportedException ();
++ }
++ }
++
++ class Discard : Expression, IAssignMethod, IMemoryLocation
++ {
++ public Discard (Location loc)
++ {
++ this.loc = loc;
++ }
++
++ public override Expression CreateExpressionTree (ResolveContext rc)
++ {
++ rc.Report.Error (8207, loc, "An expression tree cannot contain a discard");
++ return null;
++ }
++
++ protected override Expression DoResolve (ResolveContext rc)
++ {
++ type = InternalType.Discard;
++ eclass = ExprClass.Variable;
++ return this;
++ }
++
++ public override Expression DoResolveLValue (ResolveContext rc, Expression right_side)
++ {
++ if (right_side.Type == InternalType.DefaultType) {
++ rc.Report.Error (8183, loc, "Cannot infer the type of implicitly-typed discard");
++ type = InternalType.ErrorType;
++ return this;
++ }
++
++ if (right_side.Type.Kind == MemberKind.Void) {
++ rc.Report.Error (8209, loc, "Cannot assign void to a discard");
++ type = InternalType.ErrorType;
++ return this;
++ }
++
++ if (right_side != EmptyExpression.OutAccess) {
++ type = right_side.Type;
++ }
++
++ return this;
++ }
++
++ public override void Emit (EmitContext ec)
++ {
++ throw new NotImplementedException ();
++ }
++
++ public void Emit (EmitContext ec, bool leave_copy)
++ {
++ throw new NotImplementedException ();
++ }
++
++ public void EmitAssign (EmitContext ec, Expression source, bool leave_copy, bool isCompound)
++ {
++ if (leave_copy)
++ source.Emit (ec);
++ else
++ source.EmitSideEffect (ec);
++ }
++
++ public void AddressOf (EmitContext ec, AddressOp mode)
++ {
++ var temp = ec.GetTemporaryLocal (type);
++ ec.Emit (OpCodes.Ldloca, temp);
++
++ // TODO: Should free it on next statement but don't have mechanism for that yet
++ // ec.FreeTemporaryLocal (temp, type);
++ }
++ }
+ }
+diff --git a/mcs/mcs/generic.cs b/mcs/mcs/generic.cs
+index 625cd0c773f..ec2965df63b 100644
+--- a/mcs/mcs/generic.cs
++++ b/mcs/mcs/generic.cs
+@@ -693,6 +693,11 @@ namespace Mono.CSharp {
+ GetSignatureForError (), mc.GetSignatureForError (), input_variance, gtype_variance, parameters);
+ }
+
++ public TypeSpec GetAsyncMethodBuilder ()
++ {
++ return null;
++ }
++
+ public TypeSpec GetAttributeCoClass ()
+ {
+ return null;
+@@ -2292,7 +2297,7 @@ namespace Mono.CSharp {
+ ok = false;
+ }
+
+- if (te.IsPointer || te.IsSpecialRuntimeType) {
++ if (te.IsPointer || te.IsSpecialRuntimeType || te.IsByRefLike) {
+ ec.Module.Compiler.Report.Error (306, args[i].Location,
+ "The type `{0}' may not be used as a type argument",
+ te.GetSignatureForError ());
+@@ -3102,7 +3107,7 @@ namespace Mono.CSharp {
+ //
+ // Some types cannot be used as type arguments
+ //
+- if ((bound.Type.Kind == MemberKind.Void && !voidAllowed) || bound.Type.IsPointer || bound.Type.IsSpecialRuntimeType ||
++ if ((bound.Type.Kind == MemberKind.Void && !voidAllowed) || bound.Type.IsPointer || bound.Type.IsSpecialRuntimeType || bound.Type.IsByRefLike ||
+ bound.Type == InternalType.MethodGroup || bound.Type == InternalType.AnonymousMethod || bound.Type == InternalType.VarOutType ||
+ bound.Type == InternalType.ThrowExpr)
+ return;
+@@ -3110,6 +3115,9 @@ namespace Mono.CSharp {
+ if (bound.Type.IsTupleType && TupleLiteral.ContainsNoTypeElement (bound.Type))
+ return;
+
++ if (bound.Type == InternalType.DefaultType)
++ return;
++
+ var a = bounds [index];
+ if (a == null) {
+ a = new List<BoundInfo> (2);
+diff --git a/mcs/mcs/import.cs b/mcs/mcs/import.cs
+index 1cddf7c01f4..f7c4fd74b08 100644
+--- a/mcs/mcs/import.cs
++++ b/mcs/mcs/import.cs
+@@ -975,6 +975,10 @@ namespace Mono.CSharp
+ mod |= Modifiers.READONLY;
+ }
+
++ if (HasAttribute (CustomAttributeData.GetCustomAttributes (type), "IsByRefLikeAttribute", CompilerServicesNamespace)) {
++ mod |= Modifiers.REF;
++ }
++
+ break;
+ }
+ }
+@@ -1401,6 +1405,7 @@ namespace Mono.CSharp
+ public string DefaultIndexerName;
+ public bool? CLSAttributeValue;
+ public TypeSpec CoClass;
++ public TypeSpec AsyncMethodBuilder;
+
+ static bool HasMissingType (ConstructorInfo ctor)
+ {
+@@ -1522,6 +1527,20 @@ namespace Mono.CSharp
+ bag.CoClass = importer.ImportType ((MetaType) a.ConstructorArguments[0].Value);
+ continue;
+ }
++
++ if (name == "AsyncMethodBuilderAttribute") {
++ if (dt.Namespace != "System.Runtime.CompilerServices")
++ continue;
++
++ if (HasMissingType (a.Constructor))
++ continue;
++
++ if (bag == null)
++ bag = new AttributesBag ();
++
++ bag.AsyncMethodBuilder = importer.ImportType ((MetaType)a.ConstructorArguments [0].Value);
++ continue;
++ }
+ }
+ }
+
+@@ -2129,6 +2148,14 @@ namespace Mono.CSharp
+ }
+ }
+
++ public TypeSpec GetAsyncMethodBuilder ()
++ {
++ if (cattrs == null)
++ ReadAttributes ();
++
++ return cattrs.AsyncMethodBuilder;
++ }
++
+ public TypeSpec GetAttributeCoClass ()
+ {
+ if (cattrs == null)
+@@ -2445,6 +2472,11 @@ namespace Mono.CSharp
+
+ #endregion
+
++ public TypeSpec GetAsyncMethodBuilder ()
++ {
++ return null;
++ }
++
+ public TypeSpec GetAttributeCoClass ()
+ {
+ return null;
+diff --git a/mcs/mcs/membercache.cs b/mcs/mcs/membercache.cs
+index eebf71b844b..ca05d2d7afc 100644
+--- a/mcs/mcs/membercache.cs
++++ b/mcs/mcs/membercache.cs
+@@ -309,7 +309,6 @@ namespace Mono.CSharp {
+ //
+ if (!BuiltinTypeSpec.IsPrimitiveType (dt) || dt.BuiltinType == BuiltinTypeSpec.Type.Char) {
+ switch (dt.BuiltinType) {
+- case BuiltinTypeSpec.Type.String:
+ case BuiltinTypeSpec.Type.Delegate:
+ case BuiltinTypeSpec.Type.MulticastDelegate:
+ break;
+@@ -317,6 +316,9 @@ namespace Mono.CSharp {
+ if (name == Operator.GetMetadataName (Operator.OpType.Implicit) || name == Operator.GetMetadataName (Operator.OpType.Explicit)) {
+ state |= StateFlags.HasConversionOperator;
+ } else {
++ if (dt.BuiltinType == BuiltinTypeSpec.Type.String)
++ break;
++
+ state |= StateFlags.HasUserOperator;
+ }
+
+diff --git a/mcs/mcs/method.cs b/mcs/mcs/method.cs
+index ccd4898e91c..1fca10dd6d0 100644
+--- a/mcs/mcs/method.cs
++++ b/mcs/mcs/method.cs
+@@ -701,6 +701,10 @@ namespace Mono.CSharp {
+ if (MemberType.IsStatic) {
+ Error_StaticReturnType ();
+ }
++
++ if (MemberType.IsSpecialRuntimeType && Compiler.Settings.StdLib) {
++ Error_ReturnTypeCantBeRefAny (Location, ReturnType, Report);
++ }
+ }
+
+ public override void Emit ()
+@@ -716,6 +720,8 @@ namespace Mono.CSharp {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder);
+ } else if (ReturnType.HasDynamicElement) {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder, ReturnType, Location);
++ } else if (ReturnType is ReadOnlyReferenceContainer) {
++ Module.PredefinedAttributes.IsReadOnly.EmitAttribute (CreateReturnBuilder ().Builder);
+ }
+
+ if (ReturnType.HasNamedTupleElement) {
+@@ -764,6 +770,11 @@ namespace Mono.CSharp {
+ GetSignatureForError ());
+ }
+
++ public static void Error_ReturnTypeCantBeRefAny (Location loc, TypeSpec t, Report Report)
++ {
++ Report.Error (1599, loc, "The return type of `{0}' is not allowed", t.GetSignatureForError ());
++ }
++
+ public bool IsPartialDefinition {
+ get {
+ return (ModFlags & Modifiers.PARTIAL) != 0 && Block == null;
+@@ -1231,11 +1242,6 @@ namespace Mono.CSharp {
+ "Introducing `Finalize' method can interfere with destructor invocation. Did you intend to declare a destructor?");
+ }
+
+- if (Compiler.Settings.StdLib && ReturnType.IsSpecialRuntimeType) {
+- Error1599 (Location, ReturnType, Report);
+- return false;
+- }
+-
+ if (CurrentTypeParameters == null) {
+ if (base_method != null && !IsExplicitImpl) {
+ if (parameters.Count == 1 && ParameterTypes[0].BuiltinType == BuiltinTypeSpec.Type.Object && MemberName.Name == "Equals")
+@@ -1261,8 +1267,9 @@ namespace Mono.CSharp {
+ if ((ModFlags & Modifiers.ASYNC) != 0) {
+ if (ReturnType.Kind != MemberKind.Void &&
+ ReturnType != Module.PredefinedTypes.Task.TypeSpec &&
+- !ReturnType.IsGenericTask) {
+- Report.Error (1983, Location, "The return type of an async method must be void, Task, or Task<T>");
++ !ReturnType.IsGenericTask &&
++ !ReturnType.IsCustomTaskType ()) {
++ Report.Error (1983, Location, "The return type of an async method must be void or task type");
+ }
+
+ block = (ToplevelBlock) block.ConvertToAsyncTask (this, Parent.PartialContainer, parameters, ReturnType, null, Location);
+@@ -1396,11 +1403,6 @@ namespace Mono.CSharp {
+ return base.EnableOverloadChecks (overload);
+ }
+
+- public static void Error1599 (Location loc, TypeSpec t, Report Report)
+- {
+- Report.Error (1599, loc, "Method or delegate cannot return type `{0}'", t.GetSignatureForError ());
+- }
+-
+ protected override bool ResolveMemberType ()
+ {
+ if (CurrentTypeParameters != null) {
+@@ -2467,6 +2469,8 @@ namespace Mono.CSharp {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder);
+ } else if (ReturnType.HasDynamicElement) {
+ Module.PredefinedAttributes.Dynamic.EmitAttribute (CreateReturnBuilder ().Builder, ReturnType, Location);
++ } else if (ReturnType is ReadOnlyReferenceContainer) {
++ Module.PredefinedAttributes.IsReadOnly.EmitAttribute (CreateReturnBuilder ().Builder);
+ }
+
+ if (ReturnType.HasNamedTupleElement) {
+diff --git a/mcs/mcs/modifiers.cs b/mcs/mcs/modifiers.cs
+index bfae5985a03..926ab5d1848 100644
+--- a/mcs/mcs/modifiers.cs
++++ b/mcs/mcs/modifiers.cs
+@@ -53,6 +53,7 @@ namespace Mono.CSharp
+ DEBUGGER_HIDDEN = 0x400000,
+ DEBUGGER_STEP_THROUGH = 0x800000,
+ AutoProperty = 0x1000000,
++ REF = 0x2000000,
+
+ AccessibilityMask = PUBLIC | PROTECTED | INTERNAL | PRIVATE,
+ AllowedExplicitImplFlags = UNSAFE | EXTERN,
+diff --git a/mcs/mcs/module.cs b/mcs/mcs/module.cs
+index 00afac6c604..2293d825b36 100644
+--- a/mcs/mcs/module.cs
++++ b/mcs/mcs/module.cs
+@@ -265,6 +265,7 @@ namespace Mono.CSharp
+ readonly Dictionary<ArrayContainer.TypeRankPair, ArrayContainer> array_types;
+ readonly Dictionary<TypeSpec, PointerContainer> pointer_types;
+ readonly Dictionary<TypeSpec, ReferenceContainer> reference_types;
++ readonly Dictionary<TypeSpec, ReadOnlyReferenceContainer> readonly_reference_types;
+ readonly Dictionary<TypeSpec, MethodSpec> attrs_cache;
+ readonly Dictionary<TypeSpec, AwaiterDefinition> awaiters;
+ readonly Dictionary<TypeSpec, TypeInfo> type_info_cache;
+@@ -301,6 +302,7 @@ namespace Mono.CSharp
+ array_types = new Dictionary<ArrayContainer.TypeRankPair, ArrayContainer> ();
+ pointer_types = new Dictionary<TypeSpec, PointerContainer> ();
+ reference_types = new Dictionary<TypeSpec, ReferenceContainer> ();
++ readonly_reference_types = new Dictionary<TypeSpec, ReadOnlyReferenceContainer> ();
+ attrs_cache = new Dictionary<TypeSpec, MethodSpec> ();
+ awaiters = new Dictionary<TypeSpec, AwaiterDefinition> ();
+ type_info_cache = new Dictionary<TypeSpec, TypeInfo> ();
+@@ -427,6 +429,12 @@ namespace Mono.CSharp
+ }
+ }
+
++ internal Dictionary<TypeSpec, ReadOnlyReferenceContainer> ReadonlyReferenceTypesCache {
++ get {
++ return readonly_reference_types;
++ }
++ }
++
+ internal Dictionary<TypeSpec, TypeInfo> TypeInfoCache {
+ get {
+ return type_info_cache;
+diff --git a/mcs/mcs/parameter.cs b/mcs/mcs/parameter.cs
+index 2bd2a498a91..cc10eee162b 100644
+--- a/mcs/mcs/parameter.cs
++++ b/mcs/mcs/parameter.cs
+@@ -1447,7 +1447,7 @@ namespace Mono.CSharp {
+
+ expr = Child;
+
+- if (!(expr is Constant || expr is DefaultValueExpression || (expr is New && ((New) expr).IsGeneratedStructConstructor))) {
++ if (!(expr is Constant || expr is DefaultValueExpression || expr is DefaultLiteralExpression || (expr is New && ((New) expr).IsGeneratedStructConstructor))) {
+ if (!(expr is ErrorExpression)) {
+ rc.Report.Error (1736, Location,
+ "The expression being assigned to optional parameter `{0}' must be a constant or default value",
+diff --git a/mcs/mcs/statement.cs b/mcs/mcs/statement.cs
+index 58ba2795e4b..9c51128548f 100644
+--- a/mcs/mcs/statement.cs
++++ b/mcs/mcs/statement.cs
+@@ -1160,7 +1160,8 @@ namespace Mono.CSharp {
+ //
+ if (ec.CurrentAnonymousMethod is AsyncInitializer) {
+ var storey = (AsyncTaskStorey) ec.CurrentAnonymousMethod.Storey;
+- if (storey.ReturnType == ec.Module.PredefinedTypes.Task.TypeSpec) {
++ var s_return_type = storey.ReturnType;
++ if (s_return_type == ec.Module.PredefinedTypes.Task.TypeSpec) {
+ //
+ // Extra trick not to emit ret/leave inside awaiter body
+ //
+@@ -1168,8 +1169,8 @@ namespace Mono.CSharp {
+ return true;
+ }
+
+- if (storey.ReturnType.IsGenericTask)
+- block_return_type = storey.ReturnType.TypeArguments[0];
++ if (s_return_type.IsGenericTask || (s_return_type.Arity == 1 && s_return_type.IsCustomTaskType ()))
++ block_return_type = s_return_type.TypeArguments[0];
+ }
+
+ if (ec.CurrentIterator != null) {
+@@ -1220,7 +1221,7 @@ namespace Mono.CSharp {
+ return false;
+ }
+
+- if (!async_type.IsGenericTask) {
++ if (!async_type.IsGeneric) {
+ if (this is ContextualReturn)
+ return true;
+
+@@ -2368,7 +2369,12 @@ namespace Mono.CSharp {
+ if (initializer == null)
+ return null;
+
+- var c = initializer as Constant;
++ Constant c;
++ if (initializer.Type == InternalType.DefaultType)
++ c = New.Constantify (li.Type, initializer.Location);
++ else
++ c = initializer as Constant;
++
+ if (c == null) {
+ initializer.Error_ExpressionMustBeConstant (bc, initializer.Location, li.Name);
+ return null;
+@@ -2407,14 +2413,14 @@ namespace Mono.CSharp {
+ AddressTaken = 1 << 2,
+ CompilerGenerated = 1 << 3,
+ Constant = 1 << 4,
+- ForeachVariable = 1 << 5,
+- FixedVariable = 1 << 6,
+- UsingVariable = 1 << 7,
++ ForeachVariable = 1 << 5 | ReadonlyMask,
++ FixedVariable = 1 << 6 | ReadonlyMask,
++ UsingVariable = 1 << 7 | ReadonlyMask,
+ IsLocked = 1 << 8,
+ SymbolFileHidden = 1 << 9,
+ ByRef = 1 << 10,
+
+- ReadonlyMask = ForeachVariable | FixedVariable | UsingVariable
++ ReadonlyMask = 1 << 20
+ }
+
+ TypeSpec type;
+@@ -2534,7 +2540,7 @@ namespace Mono.CSharp {
+
+ public bool IsFixed {
+ get {
+- return (flags & Flags.FixedVariable) != 0;
++ return (flags & Flags.FixedVariable) == Flags.FixedVariable;
+ }
+ set {
+ flags = value ? flags | Flags.FixedVariable : flags & ~Flags.FixedVariable;
+@@ -2672,7 +2678,7 @@ namespace Mono.CSharp {
+
+ public string GetReadOnlyContext ()
+ {
+- switch (flags & Flags.ReadonlyMask) {
++ switch (flags & (Flags.ForeachVariable | Flags.FixedVariable | Flags.UsingVariable)) {
+ case Flags.FixedVariable:
+ return "fixed variable";
+ case Flags.ForeachVariable:
+@@ -8191,7 +8197,9 @@ namespace Mono.CSharp {
+ }
+
+ if (iface_candidate == null) {
+- if (expr.Type != InternalType.ErrorType) {
++ if (expr.Type == InternalType.DefaultType) {
++ rc.Report.Error (8312, loc, "Use of default literal is not valid in this context");
++ } else if (expr.Type != InternalType.ErrorType) {
+ rc.Report.Error (1579, loc,
+ "foreach statement cannot operate on variables of type `{0}' because it does not contain a definition for `{1}' or is inaccessible",
+ expr.Type.GetSignatureForError (), "GetEnumerator");
+diff --git a/mcs/mcs/tuples.cs b/mcs/mcs/tuples.cs
+index bb7faf734df..901efdc9541 100644
+--- a/mcs/mcs/tuples.cs
++++ b/mcs/mcs/tuples.cs
+@@ -432,7 +432,7 @@ namespace Mono.CSharp
+ {
+ Expression source;
+ List<Expression> targetExprs;
+- List<LocalVariable> variablesToInfer;
++ List<BlockVariable> variables;
+ Expression instance;
+
+ public TupleDeconstruct (List<Expression> targetExprs, Expression source, Location loc)
+@@ -442,10 +442,11 @@ namespace Mono.CSharp
+ this.loc = loc;
+ }
+
+- public TupleDeconstruct (List<Expression> targetExprs, List<LocalVariable> variables, Expression source, Location loc)
+- : this (targetExprs, source, loc)
++ public TupleDeconstruct (List<BlockVariable> variables, Expression source, Location loc)
+ {
+- this.variablesToInfer = variables;
++ this.source = source;
++ this.variables = variables;
++ this.loc = loc;
+ }
+
+ public override Expression CreateExpressionTree (ResolveContext ec)
+@@ -469,9 +470,18 @@ namespace Mono.CSharp
+ var src_type = src.Type;
+
+ if (src_type.IsTupleType) {
+- if (src_type.Arity != targetExprs.Count) {
++ int target_count;
++
++ if (targetExprs == null) {
++ target_count = variables.Count;
++ targetExprs = new List<Expression> (target_count);
++ } else {
++ target_count = targetExprs.Count;
++ }
++
++ if (src_type.Arity != target_count) {
+ rc.Report.Error (8132, loc, "Cannot deconstruct a tuple of `{0}' elements into `{1}' variables",
+- src_type.Arity.ToString (), targetExprs.Count.ToString ());
++ src_type.Arity.ToString (CultureInfo.InvariantCulture), target_count.ToString (CultureInfo.InvariantCulture));
+ return null;
+ }
+
+@@ -482,27 +492,44 @@ namespace Mono.CSharp
+ instance = expr_variable.CreateReferenceExpression (rc, loc);
+ }
+
+- for (int i = 0; i < targetExprs.Count; ++i) {
++ for (int i = 0; i < target_count; ++i) {
+ var tle = src_type.TypeArguments [i];
+
+- var lv = variablesToInfer? [i];
+- if (lv != null) {
+- if (InternalType.HasNoType (tle)) {
+- rc.Report.Error (8130, Location, "Cannot infer the type of implicitly-typed deconstruction variable `{0}'", lv.Name);
+- lv.Type = InternalType.ErrorType;
++ if (variables != null) {
++ var variable = variables [i].Variable;
++
++ if (variable.Type == InternalType.Discard) {
++ variables [i] = null;
++ targetExprs.Add (EmptyExpressionStatement.Instance);
+ continue;
+ }
+
+- lv.Type = tle;
+- lv.PrepareAssignmentAnalysis ((BlockContext) rc);
+- }
++ var variable_type = variables [i].TypeExpression;
++
++ targetExprs.Add (new LocalVariableReference (variable, variable.Location));
++
++ if (variable_type is VarExpr) {
++ if (InternalType.HasNoType (tle)) {
++ rc.Report.Error (8130, Location, "Cannot infer the type of implicitly-typed deconstruction variable `{0}'", variable.Name);
++ tle = InternalType.ErrorType;
++ }
+
++ variable.Type = tle;
++ } else {
++ variable.Type = variable_type.ResolveAsType (rc);
++ }
++
++ variable.PrepareAssignmentAnalysis ((BlockContext)rc);
++ }
+
+ var element_src = tupleLiteral == null ? new MemberAccess (instance, NamedTupleSpec.GetElementPropertyName (i)) : tupleLiteral.Elements [i].Expr;
+ targetExprs [i] = new SimpleAssign (targetExprs [i], element_src).Resolve (rc);
+ }
+
+ eclass = ExprClass.Value;
++
++ // TODO: The type is same only if there is no target element conversion
++ // var res = (/*byte*/ b, /*short*/ s) = (2, 4);
+ type = src.Type;
+ return this;
+ }
+@@ -527,11 +554,24 @@ namespace Mono.CSharp
+
+ public override void Emit (EmitContext ec)
+ {
+- throw new NotImplementedException ();
++ if (instance != null)
++ ((ExpressionStatement)source).EmitStatement (ec);
++
++ foreach (ExpressionStatement expr in targetExprs)
++ expr.Emit (ec);
++
++ var ctor = MemberCache.FindMember (type, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly | BindingRestriction.InstanceOnly) as MethodSpec;
++ ec.Emit (OpCodes.Newobj, ctor);
+ }
+
+ public override void EmitStatement (EmitContext ec)
+ {
++ if (variables != null) {
++ foreach (var lv in variables) {
++ lv?.Variable.CreateBuilder (ec);
++ }
++ }
++
+ if (instance != null)
+ ((ExpressionStatement) source).EmitStatement (ec);
+
+@@ -549,9 +589,6 @@ namespace Mono.CSharp
+ if (leave_copy)
+ throw new NotImplementedException ();
+
+- foreach (var lv in variablesToInfer)
+- lv.CreateBuilder (ec);
+-
+ EmitStatement (ec);
+ }
+
+@@ -563,11 +600,11 @@ namespace Mono.CSharp
+
+ public void SetGeneratedFieldAssigned (FlowAnalysisContext fc)
+ {
+- if (variablesToInfer == null)
++ if (variables == null)
+ return;
+
+- foreach (var lv in variablesToInfer)
+- fc.SetVariableAssigned (lv.VariableInfo);
++ foreach (var lv in variables)
++ fc.SetVariableAssigned (lv.Variable.VariableInfo);
+ }
+ }
+ }
+\ No newline at end of file
+diff --git a/mcs/mcs/typemanager.cs b/mcs/mcs/typemanager.cs
+index b6aff14e1c0..7a16cda2774 100644
+--- a/mcs/mcs/typemanager.cs
++++ b/mcs/mcs/typemanager.cs
+@@ -242,6 +242,7 @@ namespace Mono.CSharp
+
+ // C# 7.0
+ public readonly PredefinedType[] Tuples;
++ public readonly PredefinedType SpanGeneric;
+
+ public PredefinedTypes (ModuleContainer module)
+ {
+@@ -301,6 +302,8 @@ namespace Mono.CSharp
+ FormattableString = new PredefinedType (module, MemberKind.Class, "System", "FormattableString");
+ FormattableStringFactory = new PredefinedType (module, MemberKind.Class, "System.Runtime.CompilerServices", "FormattableStringFactory");
+
++ SpanGeneric = new PredefinedType (module, MemberKind.Struct, "System", "Span", 1);
++
+ //
+ // Define types which are used for comparison. It does not matter
+ // if they don't exist as no error report is needed
+@@ -348,6 +351,8 @@ namespace Mono.CSharp
+ if (pt.Define ())
+ pt.TypeSpec.IsTupleType = true;
+ }
++
++ SpanGeneric.Define ();
+ }
+ }
+
+@@ -430,6 +435,7 @@ namespace Mono.CSharp
+ ArrayEmpty = new PredefinedMember<MethodSpec> (module, types.Array,
+ MemberFilter.Method ("Empty", 1, ParametersCompiled.EmptyReadOnlyParameters, null));
+
++ // TODO: Must me static
+ AsyncTaskMethodBuilderCreate = new PredefinedMember<MethodSpec> (module, types.AsyncTaskMethodBuilder,
+ MemberFilter.Method ("Create", 0, ParametersCompiled.EmptyReadOnlyParameters, types.AsyncTaskMethodBuilder.TypeSpec));
+
+@@ -485,6 +491,7 @@ namespace Mono.CSharp
+ AsyncTaskMethodBuilderTask = new PredefinedMember<PropertySpec> (module, types.AsyncTaskMethodBuilder,
+ MemberFilter.Property ("Task", null));
+
++ // TODO: Must me static
+ AsyncTaskMethodBuilderGenericCreate = new PredefinedMember<MethodSpec> (module, types.AsyncTaskMethodBuilderGeneric,
+ MemberFilter.Method ("Create", 0, ParametersCompiled.EmptyReadOnlyParameters, types.AsyncVoidMethodBuilder.TypeSpec));
+
+@@ -542,6 +549,7 @@ namespace Mono.CSharp
+ AsyncTaskMethodBuilderGenericTask = new PredefinedMember<PropertySpec> (module, types.AsyncTaskMethodBuilderGeneric,
+ MemberFilter.Property ("Task", null));
+
++ // TODO: Must me static
+ AsyncVoidMethodBuilderCreate = new PredefinedMember<MethodSpec> (module, types.AsyncVoidMethodBuilder,
+ MemberFilter.Method ("Create", 0, ParametersCompiled.EmptyReadOnlyParameters, types.AsyncVoidMethodBuilder.TypeSpec));
+
+@@ -1006,9 +1014,6 @@ namespace Mono.CSharp
+
+ public T Resolve (Location loc)
+ {
+- if (member != null)
+- return member;
+-
+ if (Get () != null)
+ return member;
+
+diff --git a/mcs/mcs/typespec.cs b/mcs/mcs/typespec.cs
+index d14e1ead3e3..a58a0fe5178 100644
+--- a/mcs/mcs/typespec.cs
++++ b/mcs/mcs/typespec.cs
+@@ -225,6 +225,8 @@ namespace Mono.CSharp
+ }
+ }
+
++ public bool IsByRefLike => (modifiers & Modifiers.REF) != 0;
++
+ //
+ // Returns true for instances of System.Threading.Tasks.Task<T>
+ //
+@@ -1452,6 +1454,7 @@ namespace Mono.CSharp
+ int TypeParametersCount { get; }
+ TypeParameterSpec[] TypeParameters { get; }
+
++ TypeSpec GetAsyncMethodBuilder ();
+ TypeSpec GetAttributeCoClass ();
+ string GetAttributeDefaultMember ();
+ AttributeUsageAttribute GetAttributeUsage (PredefinedAttribute pa);
+@@ -1461,6 +1464,29 @@ namespace Mono.CSharp
+
+ class InternalType : TypeSpec, ITypeDefinition
+ {
++ sealed class InternalTypeAssembly : IAssemblyDefinition
++ {
++ public static readonly InternalTypeAssembly Instance = new InternalTypeAssembly ();
++
++ public string FullName => throw new NotImplementedException ();
++
++ public bool IsCLSCompliant => false;
++
++ public bool IsMissing => false;
++
++ public string Name => throw new NotImplementedException ();
++
++ public byte [] GetPublicKeyToken ()
++ {
++ throw new NotImplementedException ();
++ }
++
++ public bool IsFriendAssemblyTo (IAssemblyDefinition assembly)
++ {
++ return false;
++ }
++ }
++
+ public static readonly InternalType AnonymousMethod = new InternalType ("anonymous method");
+ public static readonly InternalType Arglist = new InternalType ("__arglist");
+ public static readonly InternalType MethodGroup = new InternalType ("method group");
+@@ -1470,6 +1496,8 @@ namespace Mono.CSharp
+ public static readonly InternalType ErrorType = new InternalType ("<error>");
+ public static readonly InternalType VarOutType = new InternalType ("var out");
+ public static readonly InternalType ThrowExpr = new InternalType ("throw expression");
++ public static readonly InternalType DefaultType = new InternalType ("default");
++ public static readonly InternalType Discard = new InternalType ("discard");
+
+ readonly string name;
+
+@@ -1494,7 +1522,7 @@ namespace Mono.CSharp
+
+ IAssemblyDefinition ITypeDefinition.DeclaringAssembly {
+ get {
+- throw new NotImplementedException ();
++ return InternalTypeAssembly.Instance;
+ }
+ }
+
+@@ -1561,6 +1589,11 @@ namespace Mono.CSharp
+
+ #region ITypeDefinition Members
+
++ TypeSpec ITypeDefinition.GetAsyncMethodBuilder ()
++ {
++ return null;
++ }
++
+ TypeSpec ITypeDefinition.GetAttributeCoClass ()
+ {
+ return null;
+@@ -1614,7 +1647,7 @@ namespace Mono.CSharp
+
+ public static bool HasNoType (TypeSpec type)
+ {
+- return type == AnonymousMethod || type == MethodGroup || type == NullLiteral || type == ThrowExpr;
++ return type == AnonymousMethod || type == MethodGroup || type == NullLiteral || type == ThrowExpr || type == DefaultType;
+ }
+ }
+
+@@ -1749,6 +1782,11 @@ namespace Mono.CSharp
+ }
+ }
+
++ public TypeSpec GetAsyncMethodBuilder ()
++ {
++ return null;
++ }
++
+ public TypeSpec GetAttributeCoClass ()
+ {
+ return Element.MemberDefinition.GetAttributeCoClass ();
+@@ -1996,9 +2034,10 @@ namespace Mono.CSharp
+ [System.Diagnostics.DebuggerDisplay("{DisplayDebugInfo()}")]
+ class ReferenceContainer : ElementTypeSpec
+ {
+- ReferenceContainer (TypeSpec element)
++ protected ReferenceContainer (TypeSpec element)
+ : base (MemberKind.ByRef, element, null)
+ {
++ cache = null;
+ }
+
+ public override IList<TypeSpec> Interfaces {
+@@ -2039,6 +2078,39 @@ namespace Mono.CSharp
+
+ return pc;
+ }
++
++ protected override void InitializeMemberCache(bool onlyTypes)
++ {
++ cache = Element.MemberCache;
++ }
++ }
++
++ [System.Diagnostics.DebuggerDisplay ("{DisplayDebugInfo()}")]
++ class ReadOnlyReferenceContainer : ReferenceContainer
++ {
++ public ReadOnlyReferenceContainer (TypeSpec element)
++ : base (element)
++ {
++ }
++
++ string DisplayDebugInfo ()
++ {
++ return "ref readonly " + GetSignatureForError ();
++ }
++
++ public new static ReferenceContainer MakeType (ModuleContainer module, TypeSpec element)
++ {
++ if (element.Kind == MemberKind.ByRef)
++ throw new ArgumentException ();
++
++ ReadOnlyReferenceContainer pc;
++ if (!module.ReadonlyReferenceTypesCache.TryGetValue (element, out pc)) {
++ pc = new ReadOnlyReferenceContainer (element);
++ module.ReadonlyReferenceTypesCache.Add (element, pc);
++ }
++
++ return pc;
++ }
+ }
+
+ class PointerContainer : ElementTypeSpec
+diff --git a/mcs/tests/gtest-409.cs b/mcs/tests/gtest-409.cs
+index 8db59d7e48d..606ae3685d1 100644
+--- a/mcs/tests/gtest-409.cs
++++ b/mcs/tests/gtest-409.cs
+@@ -1,3 +1,4 @@
++// Compiler options: -langversion:latest
+ using System;
+
+ //
+@@ -175,6 +176,11 @@ public class ConditionalParsing
+ var x = args ?.2f : -.2f;
+ }
+
++ void Test_23 (string args)
++ {
++ var x = args == null ? default : 1;
++ }
++
+ static void Helper<T> (T arg)
+ {
+ }
+diff --git a/mcs/tests/test-948.cs b/mcs/tests/test-948.cs
+new file mode 100644
+index 00000000000..34b3ab9a0c4
+--- /dev/null
++++ b/mcs/tests/test-948.cs
+@@ -0,0 +1,16 @@
++// Compiler options: -langversion:7.2 -unsafe
++
++using System;
++
++class X
++{
++ public static void Main ()
++ {
++ Span<int> stackSpan = stackalloc int[100];
++ }
++
++ unsafe void Foo ()
++ {
++
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-async-94.cs b/mcs/tests/test-async-94.cs
+new file mode 100644
+index 00000000000..ce9a30409bb
+--- /dev/null
++++ b/mcs/tests/test-async-94.cs
+@@ -0,0 +1,127 @@
++using System;
++using System.Threading.Tasks;
++using System.Runtime.CompilerServices;
++
++[AsyncMethodBuilder (typeof(MyTaskMethodBuilder<>))]
++class MyTask<T>
++{
++}
++
++[AsyncMethodBuilder (typeof(MyTaskMethodBuilder))]
++class MyTask
++{
++}
++
++class MyTaskMethodBuilder
++{
++ public static MyTaskMethodBuilder Create()
++ {
++ return null;
++ }
++
++ public MyTask Task {
++ get {
++ return null;
++ }
++ }
++
++ public void SetException (Exception exception)
++ {
++
++ }
++
++ public void SetResult ()
++ {
++
++ }
++
++ public void AwaitOnCompleted<TAwaiter, TStateMachine> (ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine> (ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void Start<TStateMachine> (ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void SetStateMachine (IAsyncStateMachine stateMachine)
++ {
++
++ }
++}
++
++class MyTaskMethodBuilder<T>
++{
++ public static MyTaskMethodBuilder<T> Create()
++ {
++ return null;
++ }
++
++ public MyTask<T> Task {
++ get {
++ return null;
++ }
++ }
++
++ public void SetException (Exception exception)
++ {
++
++ }
++
++ public void SetResult (T result)
++ {
++
++ }
++
++ public void AwaitOnCompleted<TAwaiter, TStateMachine> (ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : INotifyCompletion where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine> (ref TAwaiter awaiter, ref TStateMachine stateMachine) where TAwaiter : ICriticalNotifyCompletion where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void Start<TStateMachine> (ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine
++ {
++
++ }
++
++ public void SetStateMachine (IAsyncStateMachine stateMachine)
++ {
++
++ }
++}
++
++class X
++{
++ public async MyTask Test ()
++ {
++ await Task.Delay (1);
++ }
++
++ public async MyTask<int> Test2 ()
++ {
++ await Task.Delay (1);
++ return 2;
++ }
++
++ public async ValueTask<string> Test3 ()
++ {
++ await Task.Delay (1);
++ return "as";
++ }
++
++ public static void Main ()
++ {
++ var x = new X ();
++ var r1 = x.Test3 ().Result;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-default-01.cs b/mcs/tests/test-default-01.cs
+new file mode 100644
+index 00000000000..823e33c451b
+--- /dev/null
++++ b/mcs/tests/test-default-01.cs
+@@ -0,0 +1,52 @@
++// Compiler options: -langversion:latest
++
++static class X
++{
++ const int c1 = default;
++ const int c2 = default (int);
++
++ public static void Main ()
++ {
++ int a = default;
++ var b = (int) default;
++ const int c = default;
++ var d = new[] { 1, default };
++ dynamic e = default;
++ int f = checked (default);
++ (int a, int b) g = (1, default);
++ var h = 1 != default;
++ var i = default == M4 ();
++ }
++
++ static int M1 ()
++ {
++ return default;
++ }
++
++ static void M2 ()
++ {
++ try {
++ throw new System.Exception ();
++ } catch (System.Exception) when (default) {
++ }
++
++ if (default) {
++ }
++ }
++
++ static void M3 (int x = default)
++ {
++ }
++
++ static System.Func<int> M4 ()
++ {
++ return () => default;
++ }
++}
++/*
++enum E
++{
++ A = default,
++ B = default + 1
++}
++*/
+\ No newline at end of file
+diff --git a/mcs/tests/test-default-02.cs b/mcs/tests/test-default-02.cs
+new file mode 100644
+index 00000000000..0039782e5f2
+--- /dev/null
++++ b/mcs/tests/test-default-02.cs
+@@ -0,0 +1,33 @@
++// Compiler options: -langversion:latest
++
++class C
++{
++ static void Main()
++ {
++ M (default, 1);
++
++ M2 (default);
++ M2 (null);
++
++ var res = Test (default);
++ }
++
++
++ static void M<T> (T x, T y)
++ {
++ }
++
++ static void M2 (params object[] x)
++ {
++ }
++
++ static byte[] Test (S<byte> x)
++ {
++ return null;
++ }
++}
++
++struct S<T>
++{
++
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-discards-01.cs b/mcs/tests/test-discards-01.cs
+new file mode 100644
+index 00000000000..54cf29779c6
+--- /dev/null
++++ b/mcs/tests/test-discards-01.cs
+@@ -0,0 +1,36 @@
++using System;
++
++class X
++{
++ public static void Main ()
++ {
++ string s = null;
++
++ _ = 1;
++ {
++ char _ = '4';
++ }
++
++ _ = TestValue ();
++
++ _ = _ = s;
++
++ byte k1;
++ var s1 = (k1, _) = (1, s);
++
++ Func<object> l1 = () => _ = (_, _) = (1, s);
++
++ TryGetValue (out _);
++ }
++
++ static bool TryGetValue (out int arg)
++ {
++ arg = 3;
++ return true;
++ }
++
++ static int TestValue ()
++ {
++ return 4;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-named-11.cs b/mcs/tests/test-named-11.cs
+new file mode 100644
+index 00000000000..a01d2883b9c
+--- /dev/null
++++ b/mcs/tests/test-named-11.cs
+@@ -0,0 +1,13 @@
++// Compiler options: -langversion:7.2
++
++class X
++{
++ public static void Main ()
++ {
++ Test (arg: 1, "");
++ }
++
++ static void Test (int arg, string str)
++ {
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-readonly-02.cs b/mcs/tests/test-readonly-02.cs
+new file mode 100644
+index 00000000000..231b8cd8fda
+--- /dev/null
++++ b/mcs/tests/test-readonly-02.cs
+@@ -0,0 +1,27 @@
++// Compiler options: -langversion:latest
++using System;
++
++public delegate ref readonly int D (int x);
++
++class X
++{
++ public static void Main ()
++ {
++
++ }
++
++ Guid g;
++
++ ref readonly Guid TestMethod ()
++ {
++ return ref g;
++ }
++
++ ref readonly Guid TestProp {
++ get {
++ ref readonly var rg = ref g;
++ return ref rg;
++ }
++ }
++
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-readonly-03.cs b/mcs/tests/test-readonly-03.cs
+new file mode 100644
+index 00000000000..14cb958b41a
+--- /dev/null
++++ b/mcs/tests/test-readonly-03.cs
+@@ -0,0 +1,16 @@
++// Compiler options: -langversion:latest
++using System;
++
++readonly struct S
++{
++ static S shared = new S ();
++
++ public S (int arg)
++ {
++ this = shared;
++ }
++
++ public static void Main ()
++ {
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-ref-07.cs b/mcs/tests/test-ref-07.cs
+new file mode 100644
+index 00000000000..4aa16579752
+--- /dev/null
++++ b/mcs/tests/test-ref-07.cs
+@@ -0,0 +1,30 @@
++// Compiler options: -langversion:latest
++
++public readonly partial ref struct Test
++{
++ public static void Main ()
++ {
++ var m = new Test ();
++ m.Method ();
++ }
++
++ Test Method ()
++ {
++ return new Test ();
++ }
++}
++
++ref struct Second
++{
++ Test field;
++}
++
++public abstract class P
++{
++ public abstract Test Span { get; }
++}
++
++public interface II
++{
++ Test Span { get; }
++}
+diff --git a/mcs/tests/test-ref-08.cs b/mcs/tests/test-ref-08.cs
+new file mode 100644
+index 00000000000..f4ff50f4c5c
+--- /dev/null
++++ b/mcs/tests/test-ref-08.cs
+@@ -0,0 +1,101 @@
++using System;
++
++namespace ClassLibrary1
++{
++ public class C
++ {
++
++ class B
++ {
++ int v;
++ public ref int this[int index]
++ {
++ get
++ {
++ return ref v;
++ }
++ }
++ }
++
++
++ class Gen<T> where T : struct
++ {
++ T v;
++ public ref T this[int index]
++ {
++ get
++ {
++ return ref v;
++ }
++ }
++ }
++
++ struct Val
++ {
++ }
++
++ class BB
++ {
++ Val v;
++ public ref Val this[int index]
++ {
++ get
++ {
++ return ref v;
++ }
++ }
++ }
++
++ void MM ()
++ {
++ var bbb = new BB();
++ Val v1 = bbb[0];
++ bbb[1] = v1;
++
++ ref Val v2 = ref bbb[2];
++ bbb[2] = v2;
++ }
++
++ static int[] a = new int[1];
++ public static void Main()
++ {
++ var bb = new B();
++ int b = 1;
++ bb[0] = b;
++ a[0] = Add2(ref b, 2);
++
++ var bbb = new BB();
++ bbb[0] = new Val();
++
++ var v = new Val();
++ bbb[1] = v;
++
++ var v2 = bbb[2];
++
++ bbb[3] = v2;
++
++
++ bbb[3] = bbb[2];
++
++
++
++ var ggg = new Gen<Val>();
++ ggg[0] = new Val();
++
++ var g = new Val();
++ ggg[1] = v;
++
++ var g2 = ggg[2];
++
++ ggg[3] = v2;
++
++
++ ggg[3] = ggg[2];
++ }
++
++ public static ref int Add2(ref int a, int b)
++ {
++ return ref a;
++ }
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-ref-09.cs b/mcs/tests/test-ref-09.cs
+new file mode 100644
+index 00000000000..5d0e89e5c1a
+--- /dev/null
++++ b/mcs/tests/test-ref-09.cs
+@@ -0,0 +1,12 @@
++struct rigidbody { public float x; }
++
++class Program
++{
++ static rigidbody a;
++ static ref rigidbody property_returning_struct_by_ref => ref a;
++
++ static void Main()
++ {
++ System.Console.WriteLine (property_returning_struct_by_ref.x);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-ref-10.cs b/mcs/tests/test-ref-10.cs
+new file mode 100644
+index 00000000000..88e201d3174
+--- /dev/null
++++ b/mcs/tests/test-ref-10.cs
+@@ -0,0 +1,24 @@
++// Compiler options: -langversion:latest
++
++using System;
++
++ref struct ValueStringBuilder
++{
++ public override string ToString ()
++ {
++ return "aaa";
++ }
++}
++
++
++class X
++{
++ public static int Main ()
++ {
++ var s = new ValueStringBuilder ();
++ if (s.ToString () != "aaa")
++ return 1;
++
++ return 0;
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-tuple-07.cs b/mcs/tests/test-tuple-07.cs
+new file mode 100644
+index 00000000000..cc7ce5837ce
+--- /dev/null
++++ b/mcs/tests/test-tuple-07.cs
+@@ -0,0 +1,16 @@
++using System;
++using System.Collections.Generic;
++
++// Parser tests
++
++class ParserTest
++{
++ IEnumerable<(Object vertex, int distance)> Test ()
++ {
++ return null;
++ }
++
++ public static void Main ()
++ {
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/test-tuple-09.cs b/mcs/tests/test-tuple-09.cs
+new file mode 100644
+index 00000000000..3f15cae6cf1
+--- /dev/null
++++ b/mcs/tests/test-tuple-09.cs
+@@ -0,0 +1,19 @@
++using System;
++
++class TupleDeconstructionDeclaration
++{
++ public static int Main ()
++ {
++ (string s, long l) = GetValues ();
++ (var vs, var vl) = GetValues ();
++ (object o, var vl2) = GetValues ();
++ (string ds, _) = GetValues ();
++
++ return 0;
++ }
++
++ static (string, long) GetValues ()
++ {
++ return ("a", 3);
++ }
++}
+\ No newline at end of file
+diff --git a/mcs/tests/ver-il-net_4_x.xml b/mcs/tests/ver-il-net_4_x.xml
+index c2c98123305..4dbc7042a8a 100644
+--- a/mcs/tests/ver-il-net_4_x.xml
++++ b/mcs/tests/ver-il-net_4_x.xml
+@@ -14659,6 +14659,9 @@
+ <method name="Void Test_22(Boolean)" attrs="129">
+ <size>24</size>
+ </method>
++ <method name="Void Test_23(System.String)" attrs="129">
++ <size>16</size>
++ </method>
+ </type>
+ </test>
+ <test name="gtest-410.cs">
+@@ -52808,6 +52811,19 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-948.cs">
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>16</size>
++ </method>
++ <method name="Void Foo()" attrs="129">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-95.cs">
+ <type name="X">
+ <method name="Int32 Main()" attrs="150">
+@@ -66893,6 +66909,117 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-async-94.cs">
++ <type name="MyTask`1[T]">
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="MyTask">
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="MyTaskMethodBuilder">
++ <method name="MyTaskMethodBuilder Create()" attrs="150">
++ <size>10</size>
++ </method>
++ <method name="MyTask get_Task()" attrs="2182">
++ <size>10</size>
++ </method>
++ <method name="Void SetException(System.Exception)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void SetResult()" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void AwaitOnCompleted[TAwaiter,TStateMachine](TAwaiter ByRef, TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void AwaitUnsafeOnCompleted[TAwaiter,TStateMachine](TAwaiter ByRef, TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void Start[TStateMachine](TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="MyTaskMethodBuilder`1[T]">
++ <method name="MyTaskMethodBuilder`1[T] Create()" attrs="150">
++ <size>10</size>
++ </method>
++ <method name="MyTask`1[T] get_Task()" attrs="2182">
++ <size>10</size>
++ </method>
++ <method name="Void SetException(System.Exception)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void SetResult(T)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void AwaitOnCompleted[TAwaiter,TStateMachine](TAwaiter ByRef, TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void AwaitUnsafeOnCompleted[TAwaiter,TStateMachine](TAwaiter ByRef, TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void Start[TStateMachine](TStateMachine ByRef)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="134">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="X">
++ <method name="MyTask Test()" attrs="134">
++ <size>33</size>
++ </method>
++ <method name="MyTask`1[System.Int32] Test2()" attrs="134">
++ <size>33</size>
++ </method>
++ <method name="System.Threading.Tasks.ValueTask`1[System.String] Test3()" attrs="134">
++ <size>33</size>
++ </method>
++ <method name="Void Main()" attrs="150">
++ <size>23</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="X+<Test>c__async0">
++ <method name="Void MoveNext()" attrs="486">
++ <size>157</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="486">
++ <size>13</size>
++ </method>
++ </type>
++ <type name="X+<Test2>c__async1">
++ <method name="Void MoveNext()" attrs="486">
++ <size>165</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="486">
++ <size>13</size>
++ </method>
++ </type>
++ <type name="X+<Test3>c__async2">
++ <method name="Void MoveNext()" attrs="486">
++ <size>169</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="486">
++ <size>13</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-cls-00.cs">
+ <type name="CLSCLass_6">
+ <method name="Void add_Disposed(Delegate)" attrs="2182">
+@@ -68527,6 +68654,47 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-default-01.cs">
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>53</size>
++ </method>
++ <method name="Int32 M1()" attrs="145">
++ <size>10</size>
++ </method>
++ <method name="Void M2()" attrs="145">
++ <size>31</size>
++ </method>
++ <method name="Void M3(Int32)" attrs="145">
++ <size>2</size>
++ </method>
++ <method name="System.Func`1[System.Int32] M4()" attrs="145">
++ <size>38</size>
++ </method>
++ <method name="Int32 <M4>m__0()" attrs="145">
++ <size>9</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-default-02.cs">
++ <type name="C">
++ <method name="Void Main()" attrs="145">
++ <size>36</size>
++ </method>
++ <method name="Void M[T](T, T)" attrs="145">
++ <size>2</size>
++ </method>
++ <method name="Void M2(System.Object[])" attrs="145">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ <method name="Byte[] Test(S`1[System.Byte])" attrs="145">
++ <size>10</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-dictinit-01.cs">
+ <type name="Program">
+ <method name="Int32 Main()" attrs="145">
+@@ -68610,6 +68778,30 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-discards-01.cs">
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>63</size>
++ </method>
++ <method name="Boolean TryGetValue(Int32 ByRef)" attrs="145">
++ <size>13</size>
++ </method>
++ <method name="Int32 TestValue()" attrs="145">
++ <size>10</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="X+<Main>c__AnonStorey0">
++ <method name="System.Object <>m__0()" attrs="131">
++ <size>25</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-ex-filter-01.cs">
+ <type name="X">
+ <method name="Int32 Main()" attrs="150">
+@@ -70689,6 +70881,19 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-named-11.cs">
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>13</size>
++ </method>
++ <method name="Void Test(Int32, System.String)" attrs="145">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-nameof-01.cs">
+ <type name="X">
+ <method name="Int32 Main()" attrs="150">
+@@ -72778,6 +72983,49 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-readonly-02.cs">
++ <type name="D">
++ <method name="Int32& Invoke(Int32)" attrs="454">
++ <size>0</size>
++ </method>
++ <method name="System.IAsyncResult BeginInvoke(Int32, System.AsyncCallback, System.Object)" attrs="454">
++ <size>0</size>
++ </method>
++ <method name="Int32& EndInvoke(System.IAsyncResult)" attrs="454">
++ <size>0</size>
++ </method>
++ <method name="Void .ctor(Object, IntPtr)" attrs="6278">
++ <size>0</size>
++ </method>
++ </type>
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>2</size>
++ </method>
++ <method name="System.Guid& TestMethod()" attrs="129">
++ <size>15</size>
++ </method>
++ <method name="System.Guid& get_TestProp()" attrs="2177">
++ <size>17</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-readonly-03.cs">
++ <type name="S">
++ <method name="Void Main()" attrs="150">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor(Int32)" attrs="6278">
++ <size>13</size>
++ </method>
++ <method name="Void .cctor()" attrs="6289">
++ <size>15</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-ref-01.cs">
+ <type name="X">
+ <method name="Void Main()" attrs="150">
+@@ -72906,6 +73154,95 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-ref-07.cs">
++ <type name="Test">
++ <method name="Void Main()" attrs="150">
++ <size>18</size>
++ </method>
++ <method name="Test Method()" attrs="129">
++ <size>18</size>
++ </method>
++ </type>
++ <type name="P">
++ <method name="Test get_Span()" attrs="3526">
++ <size>0</size>
++ </method>
++ <method name="Void .ctor()" attrs="6276">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-ref-08.cs">
++ <type name="ClassLibrary1.C">
++ <method name="Void MM()" attrs="129">
++ <size>60</size>
++ </method>
++ <method name="Void Main()" attrs="150">
++ <size>245</size>
++ </method>
++ <method name="Int32& Add2(Int32 ByRef, Int32)" attrs="150">
++ <size>10</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ <method name="Void .cctor()" attrs="6289">
++ <size>12</size>
++ </method>
++ </type>
++ <type name="ClassLibrary1.C+B">
++ <method name="Int32& get_Item(Int32)" attrs="2182">
++ <size>15</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="ClassLibrary1.C+Gen`1[T]">
++ <method name="T& get_Item(Int32)" attrs="2182">
++ <size>15</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="ClassLibrary1.C+BB">
++ <method name="Val& get_Item(Int32)" attrs="2182">
++ <size>15</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-ref-09.cs">
++ <type name="Program">
++ <method name="rigidbody& get_property_returning_struct_by_ref()" attrs="2193">
++ <size>13</size>
++ </method>
++ <method name="Void Main()" attrs="145">
++ <size>17</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-ref-10.cs">
++ <type name="ValueStringBuilder">
++ <method name="System.String ToString()" attrs="198">
++ <size>14</size>
++ </method>
++ </type>
++ <type name="X">
++ <method name="Int32 Main()" attrs="150">
++ <size>47</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-static-using-01.cs">
+ <type name="A.B.X">
+ <method name="Int32 Test()" attrs="150">
+@@ -73374,6 +73711,56 @@
+ </method>
+ </type>
+ </test>
++ <test name="test-tuple-07.cs">
++ <type name="ParserTest">
++ <method name="System.Collections.Generic.IEnumerable`1[System.ValueTuple`2[System.Object,System.Int32]] Test()" attrs="129">
++ <size>10</size>
++ </method>
++ <method name="Void Main()" attrs="150">
++ <size>2</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-tuple-08.cs">
++ <type name="X">
++ <method name="Void Main()" attrs="150">
++ <size>19</size>
++ </method>
++ <method name="System.Threading.Tasks.Task Test()" attrs="129">
++ <size>41</size>
++ </method>
++ <method name="System.Threading.Tasks.Task`1[System.ValueTuple`2[System.Int32,System.Int32]] Waiting()" attrs="129">
++ <size>21</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ <type name="X+<Test>c__async0">
++ <method name="Void MoveNext()" attrs="486">
++ <size>212</size>
++ </method>
++ <method name="Void SetStateMachine(System.Runtime.CompilerServices.IAsyncStateMachine)" attrs="486">
++ <size>13</size>
++ </method>
++ </type>
++ </test>
++ <test name="test-tuple-09.cs">
++ <type name="TupleDeconstructionDeclaration">
++ <method name="Int32 Main()" attrs="150">
++ <size>99</size>
++ </method>
++ <method name="System.ValueTuple`2[System.String,System.Int64] GetValues()" attrs="145">
++ <size>21</size>
++ </method>
++ <method name="Void .ctor()" attrs="6278">
++ <size>7</size>
++ </method>
++ </type>
++ </test>
+ <test name="test-var-01.cs">
+ <type name="Test">
+ <method name="Int32 Main()" attrs="150">
--
Efraim Flashner <efraim@flashner.co.il> אפרים פלשנר
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next prev parent reply other threads:[~2024-12-16 17:30 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-29 15:05 [bug#74609] [PATCH] Adding a fully-bootstrapped mono unmush via Guix-patches via
2024-12-05 6:21 ` Aaron Covrig via Guix-patches via
2024-12-05 22:07 ` Richard Sent
2024-12-13 7:47 ` Ludovic Courtès
2024-12-13 12:13 ` Janneke Nieuwenhuizen
2024-12-13 21:22 ` Ludovic Courtès
2024-12-16 17:26 ` [bug#74609] [PATCH 00/21] mono bootstrap Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 01/21] gnu: Add treecc Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 02/21] gnu: Add pnet-git Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 03/21] gnu: Add pnetlib-git Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 04/21] gnu: Add mono-1.2.6 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 05/21] gnu: Add mono-1.9.1 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 06/21] gnu: Add mono-2.4.2 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 07/21] gnu: Add mono-2.6.4 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 08/21] gnu: Add mono-2.11.4 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 09/21] gnu: Add mono-3.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 10/21] gnu: Add mono-3.12.1 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 11/21] gnu: Add mono-4.9.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 12/21] gnu: Add mono-5.0.1 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 13/21] gnu: Add mono-5.1.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 14/21] gnu: Add mono-5.2.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 15/21] gnu: Add mono-5.4.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 16/21] gnu: Add mono-pre-5.8.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 17/21] gnu: Add mono-5.8.0 Efraim Flashner
2024-12-16 17:26 ` Efraim Flashner [this message]
2024-12-16 17:26 ` [bug#74609] [PATCH 19/21] gnu: Add mono-5.10.0 Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 20/21] gnu: Add libgdiplus Efraim Flashner
2024-12-16 17:26 ` [bug#74609] [PATCH 21/21] gnu: Add mono-6.12.0 Efraim Flashner
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