[bug#57050] [PATCH v4 05/14] gnu: racket: Adjust patch for "/bin/sh" in rktio.

[Philip McGrath <philip@philipmcgrath.com>]

Use '_PATH_BSHELL' instead of a custom preprocessor macro. This may not
be The Right Thing in the long term, but it at least avoids a
proliferation of 'CPPFLAGS'.

* gnu/packages/patches/racket-minimal-sh-via-rktio.patch: Rename to ...
* gnu/packages/patches/racket-rktio-bin-sh.patch: ... this, and change
to use '_PATH_BSHELL'.
* gnu/local.mk (dist_patch_DATA): Update accordingly.
* gnu/packages/racket.scm (%racket-origin)[patches]: Likewise.
(racket-vm-common-configure-flags): Stop setting 'CPPFLAGS'. Change to a
constant instead of a function, since we no longer need the delay.
(racket-vm-cgc, racket-vm-bc,
racket-vm-cs)[arguments]<#:configure-flags>: Update accordingly.
[inputs]: Remove 'bash-minimal'.
---
 gnu/local.mk                                  |  2 +-
 ...-rktio.patch => racket-rktio-bin-sh.patch} | 60 +++++++++----------
 gnu/packages/racket.scm                       | 15 ++---
 3 files changed, 35 insertions(+), 42 deletions(-)
 rename gnu/packages/patches/{racket-minimal-sh-via-rktio.patch => racket-rktio-bin-sh.patch} (54%)

diff --git a/gnu/local.mk b/gnu/local.mk
index 558fed8a0d..fae32a11e5 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -1768,7 +1768,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ripperx-missing-file.patch		\
   %D%/packages/patches/rpcbind-CVE-2017-8779.patch		\
   %D%/packages/patches/rtags-separate-rct.patch			\
-  %D%/packages/patches/racket-minimal-sh-via-rktio.patch	\
+  %D%/packages/patches/racket-rktio-bin-sh.patch		\
   %D%/packages/patches/remake-impure-dirs.patch			\
   %D%/packages/patches/restic-0.9.6-fix-tests-for-go1.15.patch	\
   %D%/packages/patches/retroarch-LIBRETRO_DIRECTORY.patch	\
diff --git a/gnu/packages/patches/racket-minimal-sh-via-rktio.patch b/gnu/packages/patches/racket-rktio-bin-sh.patch
similarity index 54%
rename from gnu/packages/patches/racket-minimal-sh-via-rktio.patch
rename to gnu/packages/patches/racket-rktio-bin-sh.patch
index 6bc2ee8331..ec6f0d9c56 100644
--- a/gnu/packages/patches/racket-minimal-sh-via-rktio.patch
+++ b/gnu/packages/patches/racket-rktio-bin-sh.patch
@@ -1,7 +1,7 @@
-From 3574b567c486d264d680a37586436c3b5a8cb978 Mon Sep 17 00:00:00 2001
+From 6a553f24439fe64fd3a2f0b5902f00590ca4241f Mon Sep 17 00:00:00 2001
 From: Philip McGrath <philip@philipmcgrath.com>
 Date: Thu, 4 Mar 2021 04:11:50 -0500
-Subject: [PATCH] patch rktio_process for "/bin/sh" on Guix
+Subject: [PATCH] rktio: patch rktio_process for "/bin/sh" on Guix
 
 Racket provides the functions `system` and `process`,
 which execute shell commands using `sh` (or `cmd` on Windows).
@@ -12,37 +12,38 @@ This patch adds a special case for "/bin/sh" to `rktio_process`,
 the C function that implements the core of `system`, `process`,
 and related Racket functions.
 
-Guix should enable the special case by defining the C preprocessor
-macro `GUIX_RKTIO_PATCH_BIN_SH` with the path to `sh` in the store.
 If:
 
-    1. The `GUIX_RKTIO_PATCH_BIN_SH` macro is defined; and
+    1. The nonstandard but ubiquitous macro `_PATH_BSHELL` from
+       <paths.h> is defined; and
 
     2. `rktio_process` is called with the exact path "/bin/sh"; and
 
-    3. The path specified by `GUIX_RKTIO_PATCH_BIN_SH` does exists;
+    3. The file specified by `_PATH_BSHELL` exists;
 
-then `rktio_process` will execute the file specified
-by `GUIX_RKTIO_PATCH_BIN_SH` instead of "/bin/sh".
+then `rktio_process` will execute the file specified by `_PATH_BSHELL`
+instead of "/bin/sh".
 
-Compared to previous attempts to patch the Racket sources,
-making this change at the C level is both:
-
-    - More comprehensive: it catches all attempts to execute "/bin/sh",
-      without having to track down the source of every occurance; and
-
-    - Less intrusive: by guarding the special case with a C preprocessor
-      conditional and a runtime check that the file in the store exists,
-      we make it much less likely that it will "leak" out of Guix.
+Checking that the path specified by `_PATH_BSHELL` exists safeguards
+against obscure errors if attempting to use stand-alone executables
+built by the patched Racket in non-Guix envoronments.
 ---
- racket/src/rktio/rktio_process.c | 21 ++++++++++++++++++++-
- 1 file changed, 20 insertions(+), 1 deletion(-)
+ racket/src/rktio/rktio_process.c | 17 ++++++++++++++++-
+ 1 file changed, 16 insertions(+), 1 deletion(-)
 
 diff --git a/racket/src/rktio/rktio_process.c b/racket/src/rktio/rktio_process.c
-index 89202436c0..465ebdd5c5 100644
+index fafaf728c1..796ebc59ce 100644
 --- a/racket/src/rktio/rktio_process.c
 +++ b/racket/src/rktio/rktio_process.c
-@@ -1224,12 +1224,14 @@ int rktio_process_allowed_flags(rktio_t *rktio)
+@@ -9,6 +9,7 @@
+ # include <sys/wait.h>
+ # include <errno.h>
+ # include <unistd.h>
++# include <paths.h> /* PATCHED for Guix */
+ # ifdef USE_ULIMIT
+ #  include <ulimit.h>
+ # endif
+@@ -1301,12 +1302,14 @@ int rktio_process_allowed_flags(rktio_t *rktio)
  /*========================================================================*/
  
  rktio_process_result_t *rktio_process(rktio_t *rktio,
@@ -58,22 +59,17 @@ index 89202436c0..465ebdd5c5 100644
    rktio_process_result_t *result;
    intptr_t to_subprocess[2], from_subprocess[2], err_subprocess[2];
    int pid;
-@@ -1255,6 +1257,23 @@ rktio_process_result_t *rktio_process(rktio_t *rktio,
+@@ -1333,6 +1336,18 @@ rktio_process_result_t *rktio_process(rktio_t *rktio,
    int i;
  #endif
  
 +/* BEGIN PATCH for Guix */
-+#if defined(GUIX_RKTIO_PATCH_BIN_SH)
-+# define GUIX_AS_a_STR_HELPER(x) #x
-+# define GUIX_AS_a_STR(x) GUIX_AS_a_STR_HELPER(x)
-+  /* A level of indirection makes `#` work as needed: */
++#if defined(_PATH_BSHELL)
 +  command =
 +      ((0 == strcmp(_guix_orig_command, "/bin/sh"))
-+       && rktio_file_exists(rktio, GUIX_AS_a_STR(GUIX_RKTIO_PATCH_BIN_SH)))
-+      ? GUIX_AS_a_STR(GUIX_RKTIO_PATCH_BIN_SH)
++       && rktio_file_exists(rktio, _PATH_BSHELL))
++      ? _PATH_BSHELL
 +      : _guix_orig_command;
-+# undef GUIX_AS_a_STR
-+# undef GUIX_AS_a_STR_HELPER
 +#else
 +  command = _guix_orig_command;
 +#endif
@@ -82,6 +78,8 @@ index 89202436c0..465ebdd5c5 100644
    /* avoid compiler warnings: */
    to_subprocess[0] = -1;
    to_subprocess[1] = -1;
+
+base-commit: 9d228d16fb99c274c964e5bef93e97333888769f
 -- 
-2.21.1 (Apple Git-122.3)
+2.32.0
 
diff --git a/gnu/packages/racket.scm b/gnu/packages/racket.scm
index 3399bcc3fe..319f63f9d2 100644
--- a/gnu/packages/racket.scm
+++ b/gnu/packages/racket.scm
@@ -36,7 +36,6 @@ (define-module (gnu packages racket)
   #:use-module (ice-9 match)
   #:use-module (gnu packages)
   #:use-module (gnu packages autotools)
-  #:use-module (gnu packages bash)
   #:use-module (gnu packages chez)
   #:use-module (gnu packages compression)
   #:use-module (gnu packages databases)
@@ -212,7 +211,7 @@ (define %racket-origin
     (sha256
      (base32 "0f9zyhdvbh4xsndrqjzl85j5ziz0rmqi676g9s1lw3h3skq2636h"))
     (file-name (git-file-name "racket" %racket-version))
-    (patches (search-patches "racket-minimal-sh-via-rktio.patch"))
+    (patches (search-patches "racket-rktio-bin-sh.patch"))
     (modules '((guix build utils)))
     (snippet
      #~(begin
@@ -232,8 +231,7 @@ (define %racket-origin
          ;; Unbundle libffi.
          (delete-file-recursively "racket/src/bc/foreign/libffi")))))
 
-(define (racket-vm-common-configure-flags)
-  ;; under a lambda abstraction to avoid evaluating bash-minimal too early.
+(define racket-vm-common-configure-flags
   #~`(,@(cond
          ((false-if-exception
            (search-input-file %build-inputs "/bin/libtool"))
@@ -248,8 +246,6 @@ (define (racket-vm-common-configure-flags)
                (list (string-append "--enable-racket=" racket))))
          (else
           '()))
-      ,(string-append "CPPFLAGS=-DGUIX_RKTIO_PATCH_BIN_SH="
-                      #$(file-append bash-minimal "/bin/sh"))
       "--disable-strip"
       ;; Using --enable-origtree lets us distinguish the VM from subsequent
       ;; layers and produces a build with the shape expected by tools such as
@@ -267,7 +263,6 @@ (define-public racket-vm-cgc
      (version %racket-version)
      (source %racket-origin)
      (inputs (list ncurses ;; <- common to all variants (for #%terminal)
-                   bash-minimal ;; <- common to all variants (for `system`)
                    libffi)) ;; <- only for BC variants
      (native-inputs (list libtool)) ;; <- only for BC variants
      (outputs '("out" "debug"))
@@ -276,7 +271,7 @@ (define-public racket-vm-cgc
       (list
        #:configure-flags
        #~(cons "--enable-cgcdefault"
-               #$(racket-vm-common-configure-flags))
+               #$racket-vm-common-configure-flags)
        ;; Tests are in packages like racket-test-core and
        ;; main-distribution-test that aren't part of the main
        ;; distribution.
@@ -359,7 +354,7 @@ (define-public racket-vm-bc
      (substitute-keyword-arguments (package-arguments racket-vm-cgc)
        ((#:configure-flags _ '())
         #~(cons "--enable-bconly"
-                #$(racket-vm-common-configure-flags)))))
+                #$racket-vm-common-configure-flags))))
     (synopsis "Racket BC [3M] implementation")
     (description "The Racket BC (``before Chez'' or ``bytecode'')
 implementation was the default before Racket 8.0.  It uses a compiler written
@@ -405,7 +400,7 @@ (define-public racket-vm-cs
                                 #$(this-package-native-input
                                    "chez-scheme-for-racket")
                                 "/bin/scheme")
-                 #$(racket-vm-common-configure-flags)))))
+                 #$racket-vm-common-configure-flags))))
     (synopsis "Racket CS implementation")
     (description "The Racket CS implementation, which uses ``Chez Scheme'' as
 its core compiler and runtime system, has been the default Racket VM
-- 
2.32.0