Re: [PATCH] [WIP] Port feature/native-comp to Windows.

["Nicolas Bértolo" <nicolasbertolo@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 377 bytes --]

> Right, I think at least on MS-Windows we need to do that.  On Posix
> platforms, Emacs will be able to start if there's no libgccjit (and
> will crash if it attempts to call any of its functions), so it might
> be a good idea to use dlopen/dlsym there as well.  But on Windows it
> is IMO critical.

The attached patch does implement dynamic loading of libgccjit in Windows.

[-- Attachment #2: 0001-Load-libgccjit-dynamically-in-Windows.patch --]
[-- Type: application/octet-stream, Size: 19705 bytes --]

From edea454459bbf434241a9f2299cb5032d4412723 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=A1s=20B=C3=A9rtolo?= <nicolasbertolo@gmail.com>
Date: Mon, 11 May 2020 20:43:06 -0300
Subject: [PATCH] Load libgccjit dynamically in Windows.

* configure.ac: don't add linker flags if compiling on Windows.
* lisp/term/w32-win.el: Map 'gccjit to "libgccjit.dll" in
`dynamic-library-alist`.
* src/comp.c: Add declarations of used libgccjit functions using
DEF_DLL_FN. Add calls to load_gccjit_if_necessary() where necessary.
* src/w32fns.c: Add Qgccjit symbol.
---
 configure.ac         |   5 +-
 lisp/term/w32-win.el |   3 +-
 src/comp.c           | 304 +++++++++++++++++++++++++++++++++++++++++++
 src/w32fns.c         |   1 +
 4 files changed, 311 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 23b94cf6ca..97639fdfba 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3793,7 +3793,10 @@ AC_DEFUN
       [AC_LINK_IFELSE([libgccjit_smoke_test], [], [libgccjit_not_found])])
     LIBS=$emacs_save_LIBS
     HAVE_NATIVE_COMP=yes
-    LIBGCCJIT_LIB="-lgccjit -ldl"
+    # mingw32 loads the library dynamically.
+    if test "${opsys}" != "mingw32"; then
+      LIBGCCJIT_LIB="-lgccjit -ldl"
+    fi
     COMP_OBJ="comp.o"
     AC_DEFINE(HAVE_NATIVE_COMP, 1, [Define to 1 if you have the libgccjit library (-lgccjit).])
 fi
diff --git a/lisp/term/w32-win.el b/lisp/term/w32-win.el
index 5901e0295e..6b9716ca30 100644
--- a/lisp/term/w32-win.el
+++ b/lisp/term/w32-win.el
@@ -289,7 +289,8 @@ libgnutls-version
        '(libxml2 "libxml2-2.dll" "libxml2.dll")
        '(zlib "zlib1.dll" "libz-1.dll")
        '(lcms2 "liblcms2-2.dll")
-       '(json "libjansson-4.dll")))
+       '(json "libjansson-4.dll")
+       '(gccjit "libgccjit.dll")))
 
 ;;; multi-tty support
 (defvar w32-initialized nil
diff --git a/src/comp.c b/src/comp.c
index 69525acfc0..d7fd408366 100644
--- a/src/comp.c
+++ b/src/comp.c
@@ -36,6 +36,291 @@
 #include "blockinput.h"
 #include "sha512.h"
 
+\f
+/********************************/
+/* Dynamic loading of libgccjit */
+/********************************/
+
+#ifdef WINDOWSNT
+# include "w32common.h"
+bool gccjit_initialized;
+
+/* In alphabetical order */
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_rvalue_from_int,
+            (gcc_jit_context *ctxt, gcc_jit_type *numeric_type, int value));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_lvalue_as_rvalue,
+            (gcc_jit_lvalue *lvalue));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_rvalue_access_field,
+            (gcc_jit_rvalue *struct_or_union, gcc_jit_location *loc,
+             gcc_jit_field *field));
+DEF_DLL_FN (void, gcc_jit_block_add_comment,
+            (gcc_jit_block *block, gcc_jit_location *loc, const char *text));
+DEF_DLL_FN (void, gcc_jit_context_release, (gcc_jit_context *ctxt));
+DEF_DLL_FN (const char *, gcc_jit_context_get_first_error,
+            (gcc_jit_context *ctxt));
+DEF_DLL_FN (gcc_jit_block *, gcc_jit_function_new_block,
+            (gcc_jit_function *func, const char *name));
+DEF_DLL_FN (gcc_jit_context *, gcc_jit_context_acquire, (void));
+DEF_DLL_FN (gcc_jit_field *, gcc_jit_context_new_field,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_type *type,
+             const char *name));
+DEF_DLL_FN (gcc_jit_function *, gcc_jit_context_get_builtin_function,
+            (gcc_jit_context *ctxt, const char *name));
+DEF_DLL_FN (gcc_jit_function *, gcc_jit_context_new_function,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             enum gcc_jit_function_kind kind, gcc_jit_type *return_type,
+             const char *name, int num_params, gcc_jit_param **params,
+             int is_variadic));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_context_new_array_access,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_rvalue *ptr,
+             gcc_jit_rvalue *index));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_context_new_global,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             enum gcc_jit_global_kind kind, gcc_jit_type *type,
+             const char *name));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_function_new_local,
+            (gcc_jit_function *func, gcc_jit_location *loc, gcc_jit_type *type,
+             const char *name));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_lvalue_access_field,
+            (gcc_jit_lvalue *struct_or_union, gcc_jit_location *loc,
+             gcc_jit_field *field));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_param_as_lvalue, (gcc_jit_param *param));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_rvalue_dereference,
+            (gcc_jit_rvalue *rvalue, gcc_jit_location *loc));
+DEF_DLL_FN (gcc_jit_lvalue *, gcc_jit_rvalue_dereference_field,
+            (gcc_jit_rvalue *ptr, gcc_jit_location *loc, gcc_jit_field *field));
+DEF_DLL_FN (gcc_jit_param *, gcc_jit_context_new_param,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_type *type,
+             const char *name));
+DEF_DLL_FN (gcc_jit_param *, gcc_jit_function_get_param,
+            (gcc_jit_function *func, int index));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_binary_op,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             enum gcc_jit_binary_op op, gcc_jit_type *result_type,
+             gcc_jit_rvalue *a, gcc_jit_rvalue *b));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_call,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             gcc_jit_function *func, int numargs , gcc_jit_rvalue **args));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_call_through_ptr,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             gcc_jit_rvalue *fn_ptr, int numargs, gcc_jit_rvalue **args));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_comparison,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             enum gcc_jit_comparison op, gcc_jit_rvalue *a, gcc_jit_rvalue *b));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_rvalue_from_long,
+            (gcc_jit_context *ctxt, gcc_jit_type *numeric_type, long value));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_rvalue_from_ptr,
+            (gcc_jit_context *ctxt, gcc_jit_type *pointer_type, void *value));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_context_new_unary_op,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             enum gcc_jit_unary_op op, gcc_jit_type *result_type,
+             gcc_jit_rvalue *rvalue));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_lvalue_get_address,
+            (gcc_jit_lvalue *lvalue, gcc_jit_location *loc));
+DEF_DLL_FN (gcc_jit_rvalue *, gcc_jit_param_as_rvalue, (gcc_jit_param *param));
+DEF_DLL_FN (gcc_jit_struct *, gcc_jit_context_new_opaque_struct,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name));
+DEF_DLL_FN (gcc_jit_struct *, gcc_jit_context_new_struct_type,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name,
+             int num_fields, gcc_jit_field **fields));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_context_get_int_type,
+            (gcc_jit_context *ctxt, int num_bytes, int is_signed));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_context_get_type,
+            (gcc_jit_context *ctxt, enum gcc_jit_types type_));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_context_new_array_type,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             gcc_jit_type *element_type, int num_elements));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_context_new_function_ptr_type,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc,
+             gcc_jit_type *return_type, int num_params,
+             gcc_jit_type **param_types, int is_variadic));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_context_new_union_type,
+            (gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name,
+             int num_fields, gcc_jit_field **fields));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_rvalue_get_type, (gcc_jit_rvalue *rvalue));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_struct_as_type,
+            (gcc_jit_struct *struct_type));
+DEF_DLL_FN (gcc_jit_type *, gcc_jit_type_get_pointer, (gcc_jit_type *type));
+DEF_DLL_FN (void, gcc_jit_block_add_assignment,
+            (gcc_jit_block *block, gcc_jit_location *loc, gcc_jit_lvalue *lvalue,
+             gcc_jit_rvalue *rvalue));
+DEF_DLL_FN (void, gcc_jit_block_add_eval,
+            (gcc_jit_block *block, gcc_jit_location *loc,
+             gcc_jit_rvalue *rvalue));
+DEF_DLL_FN (void, gcc_jit_block_end_with_conditional,
+            (gcc_jit_block *block, gcc_jit_location *loc,
+             gcc_jit_rvalue *boolval, gcc_jit_block *on_true,
+             gcc_jit_block *on_false));
+DEF_DLL_FN (void, gcc_jit_block_end_with_jump,
+            (gcc_jit_block *block, gcc_jit_location *loc,
+             gcc_jit_block *target));
+DEF_DLL_FN (void, gcc_jit_block_end_with_return,
+            (gcc_jit_block *block, gcc_jit_location *loc,
+             gcc_jit_rvalue *rvalue));
+DEF_DLL_FN (void, gcc_jit_block_end_with_void_return,
+            (gcc_jit_block *block, gcc_jit_location *loc));
+DEF_DLL_FN (void, gcc_jit_context_compile_to_file,
+            (gcc_jit_context *ctxt, enum gcc_jit_output_kind output_kind,
+             const char *output_path));
+DEF_DLL_FN (void, gcc_jit_context_dump_reproducer_to_file,
+            (gcc_jit_context *ctxt, const char *path));
+DEF_DLL_FN (void, gcc_jit_context_dump_to_file,
+            (gcc_jit_context *ctxt, const char *path, int update_locations));
+DEF_DLL_FN (void, gcc_jit_context_set_bool_option,
+            (gcc_jit_context *ctxt, enum gcc_jit_bool_option opt, int value));
+DEF_DLL_FN (void, gcc_jit_context_set_int_option,
+            (gcc_jit_context *ctxt, enum gcc_jit_int_option opt, int value));
+DEF_DLL_FN (void, gcc_jit_context_set_logfile,
+            (gcc_jit_context *ctxt, FILE *logfile, int flags, int verbosity));
+DEF_DLL_FN (void, gcc_jit_struct_set_fields,
+            (gcc_jit_struct *struct_type, gcc_jit_location *loc, int num_fields,
+             gcc_jit_field **fields));
+
+static bool
+init_gccjit_functions(void)
+{
+  HMODULE library;
+
+  if (!(library = w32_delayed_load (Qgccjit)))
+    {
+      return false;
+    }
+
+  /* In alphabetical order */
+  LOAD_DLL_FN(library, gcc_jit_block_add_assignment);
+  LOAD_DLL_FN(library, gcc_jit_block_add_comment);
+  LOAD_DLL_FN(library, gcc_jit_block_add_eval);
+  LOAD_DLL_FN(library, gcc_jit_block_end_with_conditional);
+  LOAD_DLL_FN(library, gcc_jit_block_end_with_jump);
+  LOAD_DLL_FN(library, gcc_jit_block_end_with_return);
+  LOAD_DLL_FN(library, gcc_jit_block_end_with_void_return);
+  LOAD_DLL_FN(library, gcc_jit_context_acquire);
+  LOAD_DLL_FN(library, gcc_jit_context_compile_to_file);
+  LOAD_DLL_FN(library, gcc_jit_context_dump_reproducer_to_file);
+  LOAD_DLL_FN(library, gcc_jit_context_dump_to_file);
+  LOAD_DLL_FN(library, gcc_jit_context_get_builtin_function);
+  LOAD_DLL_FN(library, gcc_jit_context_get_first_error);
+  LOAD_DLL_FN(library, gcc_jit_context_get_int_type);
+  LOAD_DLL_FN(library, gcc_jit_context_get_type);
+  LOAD_DLL_FN(library, gcc_jit_context_new_array_access);
+  LOAD_DLL_FN(library, gcc_jit_context_new_array_type);
+  LOAD_DLL_FN(library, gcc_jit_context_new_binary_op);
+  LOAD_DLL_FN(library, gcc_jit_context_new_call);
+  LOAD_DLL_FN(library, gcc_jit_context_new_call_through_ptr);
+  LOAD_DLL_FN(library, gcc_jit_context_new_comparison);
+  LOAD_DLL_FN(library, gcc_jit_context_new_field);
+  LOAD_DLL_FN(library, gcc_jit_context_new_function);
+  LOAD_DLL_FN(library, gcc_jit_context_new_function_ptr_type);
+  LOAD_DLL_FN(library, gcc_jit_context_new_global);
+  LOAD_DLL_FN(library, gcc_jit_context_new_opaque_struct);
+  LOAD_DLL_FN(library, gcc_jit_context_new_param);
+  LOAD_DLL_FN(library, gcc_jit_context_new_rvalue_from_int);
+  LOAD_DLL_FN(library, gcc_jit_context_new_rvalue_from_long);
+  LOAD_DLL_FN(library, gcc_jit_context_new_rvalue_from_ptr);
+  LOAD_DLL_FN(library, gcc_jit_context_new_struct_type);
+  LOAD_DLL_FN(library, gcc_jit_context_new_unary_op);
+  LOAD_DLL_FN(library, gcc_jit_context_new_union_type);
+  LOAD_DLL_FN(library, gcc_jit_context_release);
+  LOAD_DLL_FN(library, gcc_jit_context_set_bool_option);
+  LOAD_DLL_FN(library, gcc_jit_context_set_int_option);
+  LOAD_DLL_FN(library, gcc_jit_context_set_logfile);
+  LOAD_DLL_FN(library, gcc_jit_function_get_param);
+  LOAD_DLL_FN(library, gcc_jit_function_new_block);
+  LOAD_DLL_FN(library, gcc_jit_function_new_local);
+  LOAD_DLL_FN(library, gcc_jit_lvalue_access_field);
+  LOAD_DLL_FN(library, gcc_jit_lvalue_as_rvalue);
+  LOAD_DLL_FN(library, gcc_jit_lvalue_get_address);
+  LOAD_DLL_FN(library, gcc_jit_param_as_lvalue);
+  LOAD_DLL_FN(library, gcc_jit_param_as_rvalue);
+  LOAD_DLL_FN(library, gcc_jit_rvalue_access_field);
+  LOAD_DLL_FN(library, gcc_jit_rvalue_dereference);
+  LOAD_DLL_FN(library, gcc_jit_rvalue_dereference_field);
+  LOAD_DLL_FN(library, gcc_jit_rvalue_get_type);
+  LOAD_DLL_FN(library, gcc_jit_struct_as_type);
+  LOAD_DLL_FN(library, gcc_jit_struct_set_fields);
+  LOAD_DLL_FN(library, gcc_jit_type_get_pointer);
+
+  return true;
+}
+
+/* In alphabetical order */
+#define gcc_jit_block_add_assignment fn_gcc_jit_block_add_assignment
+#define gcc_jit_block_add_comment fn_gcc_jit_block_add_comment
+#define gcc_jit_block_add_eval fn_gcc_jit_block_add_eval
+#define gcc_jit_block_end_with_conditional fn_gcc_jit_block_end_with_conditional
+#define gcc_jit_block_end_with_jump fn_gcc_jit_block_end_with_jump
+#define gcc_jit_block_end_with_return fn_gcc_jit_block_end_with_return
+#define gcc_jit_block_end_with_void_return fn_gcc_jit_block_end_with_void_return
+#define gcc_jit_context_acquire fn_gcc_jit_context_acquire
+#define gcc_jit_context_compile_to_file fn_gcc_jit_context_compile_to_file
+#define gcc_jit_context_dump_reproducer_to_file fn_gcc_jit_context_dump_reproducer_to_file
+#define gcc_jit_context_dump_to_file fn_gcc_jit_context_dump_to_file
+#define gcc_jit_context_get_builtin_function fn_gcc_jit_context_get_builtin_function
+#define gcc_jit_context_get_first_error fn_gcc_jit_context_get_first_error
+#define gcc_jit_context_get_int_type fn_gcc_jit_context_get_int_type
+#define gcc_jit_context_get_type fn_gcc_jit_context_get_type
+#define gcc_jit_context_new_array_access fn_gcc_jit_context_new_array_access
+#define gcc_jit_context_new_array_type fn_gcc_jit_context_new_array_type
+#define gcc_jit_context_new_binary_op fn_gcc_jit_context_new_binary_op
+#define gcc_jit_context_new_call fn_gcc_jit_context_new_call
+#define gcc_jit_context_new_call_through_ptr fn_gcc_jit_context_new_call_through_ptr
+#define gcc_jit_context_new_comparison fn_gcc_jit_context_new_comparison
+#define gcc_jit_context_new_field fn_gcc_jit_context_new_field
+#define gcc_jit_context_new_function fn_gcc_jit_context_new_function
+#define gcc_jit_context_new_function_ptr_type fn_gcc_jit_context_new_function_ptr_type
+#define gcc_jit_context_new_global fn_gcc_jit_context_new_global
+#define gcc_jit_context_new_opaque_struct fn_gcc_jit_context_new_opaque_struct
+#define gcc_jit_context_new_param fn_gcc_jit_context_new_param
+#define gcc_jit_context_new_rvalue_from_int fn_gcc_jit_context_new_rvalue_from_int
+#define gcc_jit_context_new_rvalue_from_long fn_gcc_jit_context_new_rvalue_from_long
+#define gcc_jit_context_new_rvalue_from_ptr fn_gcc_jit_context_new_rvalue_from_ptr
+#define gcc_jit_context_new_struct_type fn_gcc_jit_context_new_struct_type
+#define gcc_jit_context_new_unary_op fn_gcc_jit_context_new_unary_op
+#define gcc_jit_context_new_union_type fn_gcc_jit_context_new_union_type
+#define gcc_jit_context_release fn_gcc_jit_context_release
+#define gcc_jit_context_set_bool_option fn_gcc_jit_context_set_bool_option
+#define gcc_jit_context_set_int_option fn_gcc_jit_context_set_int_option
+#define gcc_jit_context_set_logfile fn_gcc_jit_context_set_logfile
+#define gcc_jit_function_get_param fn_gcc_jit_function_get_param
+#define gcc_jit_function_new_block fn_gcc_jit_function_new_block
+#define gcc_jit_function_new_local fn_gcc_jit_function_new_local
+#define gcc_jit_lvalue_access_field fn_gcc_jit_lvalue_access_field
+#define gcc_jit_lvalue_as_rvalue fn_gcc_jit_lvalue_as_rvalue
+#define gcc_jit_lvalue_get_address fn_gcc_jit_lvalue_get_address
+#define gcc_jit_param_as_lvalue fn_gcc_jit_param_as_lvalue
+#define gcc_jit_param_as_rvalue fn_gcc_jit_param_as_rvalue
+#define gcc_jit_rvalue_access_field fn_gcc_jit_rvalue_access_field
+#define gcc_jit_rvalue_dereference fn_gcc_jit_rvalue_dereference
+#define gcc_jit_rvalue_dereference_field fn_gcc_jit_rvalue_dereference_field
+#define gcc_jit_rvalue_get_type fn_gcc_jit_rvalue_get_type
+#define gcc_jit_struct_as_type fn_gcc_jit_struct_as_type
+#define gcc_jit_struct_set_fields fn_gcc_jit_struct_set_fields
+#define gcc_jit_type_get_pointer fn_gcc_jit_type_get_pointer
+
+#endif
+
+static bool
+load_gccjit_if_necessary(bool mandatory)
+{
+#ifdef WINDOWSNT
+  if (!gccjit_initialized)
+    {
+      Lisp_Object status;
+      gccjit_initialized = init_gccjit_functions ();
+      status = gccjit_initialized ? Qt : Qnil;
+      Vlibrary_cache = Fcons (Fcons (Qjson, status), Vlibrary_cache);
+    }
+
+  if (mandatory && !gccjit_initialized)
+    xsignal1(Qnative_compiler_error, build_string("libgccjit not found"));
+
+  return gccjit_initialized;
+#else
+  return true;
+#endif
+}
+
+\f
 /* C symbols emitted for the load relocation mechanism.  */
 #define CURRENT_THREAD_RELOC_SYM "current_thread_reloc"
 #define PURE_PTR_SYM "pure_ptr"
@@ -3328,6 +3613,8 @@ DEFUN ("comp--init-ctxt", Fcomp__init_ctxt, Scomp__init_ctxt,
        doc: /* Initialize the native compiler context. Return t on success.  */)
      (void)
 {
+  load_gccjit_if_necessary(true);
+
   if (comp.ctxt)
     {
       xsignal1 (Qnative_ice,
@@ -3474,6 +3761,8 @@ DEFUN ("comp--release-ctxt", Fcomp__release_ctxt, Scomp__release_ctxt,
        doc: /* Release the native compiler context.  */)
      (void)
 {
+  load_gccjit_if_necessary(true);
+
   if (comp.ctxt)
     gcc_jit_context_release (comp.ctxt);
 
@@ -3490,6 +3779,8 @@ DEFUN ("comp--compile-ctxt-to-file", Fcomp__compile_ctxt_to_file,
        doc: /* Compile as native code the current context to file.  */)
      (Lisp_Object base_name)
 {
+  load_gccjit_if_necessary(true);
+
   CHECK_STRING (base_name);
 
   gcc_jit_context_set_int_option (comp.ctxt,
@@ -3660,6 +3951,9 @@ maybe_defer_native_compilation (Lisp_Object function_name,
       fflush (f);
     }
 #endif
+  if (!load_gccjit_if_necessary(false))
+    return;
+
   if (!comp_deferred_compilation
       || noninteractive
       || !NILP (Vpurify_flag)
@@ -3928,6 +4222,15 @@ DEFUN ("native-elisp-load", Fnative_elisp_load, Snative_elisp_load, 1, 2, 0,
   return Qt;
 }
 
+DEFUN ("native-comp-available-p", Fnative_comp_available_p,
+       Snative_comp_available_p, 0, 0, 0,
+       doc: /* Returns t if native compilation of Lisp files is available in
+this instance of Emacs. */)
+  (void)
+{
+  return load_gccjit_if_necessary(false) ? Qt : Qnil;
+}
+
 \f
 void
 syms_of_comp (void)
@@ -4039,6 +4342,7 @@ syms_of_comp (void)
   defsubr (&Scomp__register_subr);
   defsubr (&Scomp__late_register_subr);
   defsubr (&Snative_elisp_load);
+  defsubr (&Snative_comp_available_p);
 
   staticpro (&comp.exported_funcs_h);
   comp.exported_funcs_h = Qnil;
diff --git a/src/w32fns.c b/src/w32fns.c
index e595b0285a..eeb73489dd 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -10462,6 +10462,7 @@ syms_of_w32fns (void)
   DEFSYM (Qzlib, "zlib");
   DEFSYM (Qlcms2, "lcms2");
   DEFSYM (Qjson, "json");
+  DEFSYM (Qgccjit, "gccjit");
 
   Fput (Qundefined_color, Qerror_conditions,
 	pure_list (Qundefined_color, Qerror));
-- 
2.25.1.windows.1