gnat12: Add support for x86_64-darwin

pkgs/development/compilers/gcc/10/default.nix

···
 
   preConfigure = (import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
   }) + ''
     ln -sf ${libxcrypt}/include/crypt.h libsanitizer/sanitizer_common/crypt.h
   '';

pkgs/development/compilers/gcc/11/default.nix

···
 
   preConfigure = (import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
   }) + ''
     ln -sf ${libxcrypt}/include/crypt.h libsanitizer/sanitizer_common/crypt.h
   '';

pkgs/development/compilers/gcc/12/default.nix

···
         })
       ]
 
+      # Fix detection of bootstrap compiler Ada support (cctools as) on Nix Darwin
+      ++ optional (stdenv.isDarwin && langAda) ../ada-cctools-as-detection-configure.patch
+
       # Obtain latest patch with ../update-mcfgthread-patches.sh
       ++ optional (!crossStageStatic && targetPlatform.isMinGW && threadsCross.model == "mcf") ./Added-mcf-thread-model-support-from-mcfgthread.patch;
 
···
 
   preConfigure = (import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
   }) + ''
     ln -sf ${libxcrypt}/include/crypt.h libsanitizer/sanitizer_common/crypt.h
   '';

pkgs/development/compilers/gcc/4.8/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform langJava langGo crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform langJava langGo crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/4.9/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform langJava langGo crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform langJava langGo crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/6/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform gnatboot langJava langAda langGo crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform gnatboot langJava langAda langGo crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/7/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform langGo crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform langGo crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/8/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform langGo crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform langGo crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/9/default.nix

···
 
   preConfigure = import ../common/pre-configure.nix {
     inherit lib;
-    inherit version targetPlatform hostPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
+    inherit version targetPlatform hostPlatform buildPlatform gnatboot langAda langGo langJit crossStageStatic enableMultilib;
   };
 
   dontDisableStatic = true;

pkgs/development/compilers/gcc/ada-cctools-as-detection-configure.patch

···
+As originally implemented, the error message check
+described in the configure script
+breaks detection of Ada compiler support on x86_64-darwin,
+because the assembler in the version of cctools currently used
+unconditionally emits a deprecation message to stdout,
+with no way to disable it.
+
+Furthermore, GCC 3.4 was the minimum version needed to build GNAT
+as far back as GCC 4.4 (see the GCC git repo, tags/releases/gcc-4.4.0,
+gcc/doc/install.texi, lines 2052-2053 [1]);
+GCC 3.4 is newer than any of the broken GCC versions
+that the configure script works around
+(see the part of the comment in the configure script
+before the context in the patch below),
+and GCC 4.4 is older than any GCC that Nix currently packages (GCC 4.8).
+
+We therefore choose to not check for error messages,
+and just check for an error code.
+There's no harm in still checking for an object file being created, though.
+
+[1]: https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/doc/install.texi;h=6bdfbece981f7fb6c26da672d45e5d3ba7879c69;hb=b7fc996728085c0591ea7c5d0e1c84a8f6a29bd8#l2052
+--- a/configure        2022-08-19 18:09:52.000000000 +1000
++++ b/configure        2022-12-26 17:30:49.000000000 +1100
+@@ -5622,8 +5622,7 @@
+ # Other compilers, like HP Tru64 UNIX cc, exit successfully when
+ # given a .adb file, but produce no object file.  So we must check
+ # if an object file was really produced to guard against this.
+-errors=`(${CC} -c conftest.adb) 2>&1 || echo failure`
+-if test x"$errors" = x && test -f conftest.$ac_objext; then
++if ${CC} -c conftest.adb && test -f conftest.$ac_objext; then
+   acx_cv_cc_gcc_supports_ada=yes
+ fi
+ rm -f conftest.*

pkgs/development/compilers/gcc/common/pre-configure.nix

···
-{ lib, version, hostPlatform, targetPlatform
+{ lib, version, buildPlatform, hostPlatform, targetPlatform
 , gnatboot ? null
 , langAda ? false
 , langJava ? false
···
   export lib=$out;
 '' + lib.optionalString langAda ''
   export PATH=${gnatboot}/bin:$PATH
+''
+
+# On x86_64-darwin, the gnatboot bootstrap compiler that we need to build a
+# native GCC with Ada support emits assembly that is accepted by the Clang
+# integrated assembler, but not by the GNU assembler in cctools-port that Nix
+# usually in the x86_64-darwin stdenv.  In particular, x86_64-darwin gnatboot
+# emits MOVQ as the mnemonic for quadword interunit moves, such as between XMM
+# and general registers (e.g "movq %xmm0, %rbp"); the cctools-port assembler,
+# however, only recognises MOVD for such moves.
+#
+# Therefore, for native x86_64-darwin builds that support Ada, we have to use
+# the Clang integrated assembler to build (at least stage 1 of) GCC, but have to
+# target GCC at the cctools-port GNU assembler.  In the wrapped x86_64-darwin
+# gnatboot, the former is provided as `as`, while the latter is provided as
+# `gas`.
+#
++ lib.optionalString (
+    langAda
+    && buildPlatform == hostPlatform
+    && hostPlatform == targetPlatform
+    && targetPlatform.isx86_64
+    && targetPlatform.isDarwin
+  ) ''
+  export AS_FOR_BUILD=${gnatboot}/bin/as
+  export AS_FOR_TARGET=${gnatboot}/bin/gas
 ''
 
 # NOTE 2020/3/18: This environment variable prevents configure scripts from

pkgs/top-level/all-packages.nix

···
          && stdenv.buildPlatform == stdenv.hostPlatform
       then buildPackages.gnatboot12
       else buildPackages.gnat12;
+    stdenv =
+      if stdenv.hostPlatform == stdenv.targetPlatform
+         && stdenv.buildPlatform == stdenv.hostPlatform
+         && stdenv.buildPlatform.isDarwin
+         && stdenv.buildPlatform.isx86_64
+      then overrideCC stdenv gnatboot12
+      else stdenv;
   });
 
   gnatboot = gnatboot12;