gnumake: do not use MAKE_CXX

Removes unnecessary C++ compiler reference when CXX environment variable is set to an absolute path.
2024-08-17 22:40:12 +03:00
parent e0626c756e
commit 3f648e2891
2 changed files with 68 additions and 2 deletions
@@ -1,7 +1,7 @@
 { lib
 , stdenv
 , fetchurl
-, updateAutotoolsGnuConfigScriptsHook
+, autoreconfHook
 , guileSupport ? false, guile
 # avoid guile depend on bootstrap to prevent dependency cycles
 , inBootstrap ? false
@@ -24,6 +24,8 @@ stdenv.mkDerivation rec {

  # to update apply these patches with `git am *.patch` to https://git.savannah.gnu.org/git/make.git
  patches = [
+    # See patch message.
+    ./make-cxx.patch
    # Replaces /bin/sh with sh, see patch file for reasoning
    ./0001-No-impure-bin-sh.patch
    # Purity: don't look for library dependencies (of the form `-lfoo') in /lib
@@ -32,7 +34,7 @@ stdenv.mkDerivation rec {
    ./0002-remove-impure-dirs.patch
  ];

-  nativeBuildInputs = [ updateAutotoolsGnuConfigScriptsHook ] ++ lib.optionals guileEnabled [ pkg-config ];
+  nativeBuildInputs = [ autoreconfHook pkg-config ];
  buildInputs = lib.optionals guileEnabled [ guile ];

  configureFlags = lib.optional guileEnabled "--with-guile"
@@ -0,0 +1,64 @@
+Do not search for a C++ compiler and set MAKE_CXX.
+
+Removes unnecessary reference to C++ compiler if CXX is set to an
+absolute path. If CXX is not an absolute path, we avoid defaulting CXX
+to a compiler name that was used to build the package.
+
+Context: GNU Make defines default values for CC, CXX and other
+environment variables. For CXX, it usually defaults to g++, however,
+FreeBSD and OpenBSD no longer ship GCC as a system compiler (and use
+Clang instead). For C compiler, POSIX standardizes the name to be "cc",
+but there is no such standard for C++ compiler name. As a fix, GNU Make
+uses CXX set for build as a default (via MAKE_CXX preprocessor macro in
+the source code).
+
+We revert the change that added this behavior and set the default to c++
+or g++ that does not depend on the build platform.
+
+In stdenv, CXX environment variable is always defined and overrides the
+default value.
+
+References:
+• https://savannah.gnu.org/bugs/?63668
+• https://git.savannah.gnu.org/cgit/make.git/commit/?id=ffa28f3914ff402b3915f75e4fed86ac6fb1449d
+
+--- a/configure.ac
+++ b/configure.ac
+@@ -37,6 +37,4 @@ AM_INIT_AUTOMAKE([1.16.1 foreign -Werror -Wall])
+ # Checks for programs.
+ AC_USE_SYSTEM_EXTENSIONS
+ AC_PROG_CC
+-AC_PROG_CXX
+-AC_DEFINE_UNQUOTED(MAKE_CXX, ["$CXX"], [Default C++ compiler.])
+
+--- a/src/default.c
+++ b/src/default.c
+@@ -528,22 +528,15 @@ static const char *default_variables[] =
+ #ifdef GCC_IS_NATIVE
+     "CC", "gcc",
+     "OBJC", "gcc",
+# ifdef __MSDOS__
+    "CXX", "gpp",       /* g++ is an invalid name on MSDOS */
+# else
+    "CXX", "g++",
+# endif /* __MSDOS__ */
+ #else
+     "CC", "cc",
+     "OBJC", "cc",
+    "CXX", "c++",
+ #endif
+-#ifdef MAKE_CXX
+-    "CXX", MAKE_CXX,
+-#else
+-# ifdef GCC_IS_NATIVE
+-#  ifdef __MSDOS__
+-    "CXX", "gpp",       /* g++ is an invalid name on MSDOS */
+-#  else
+-    "CXX", "gcc",
+-#  endif /* __MSDOS__ */
+-# else
+-    "CXX", "g++",
+-# endif
+-#endif
+     /* This expands to $(CO) $(COFLAGS) $< $@ if $@ does not exist,
+        and to the empty string if $@ does exist.  */