gcc: enable stripping for cross-compilers

With explicit support for distinction between Host and Target strip paths
we can now safely strip ELF binaries with their according strip tools
without fear of damaging binaries due to architecture mismatch.

Closure size change for `pkgsCross.mingwW64.gcc12Stdenv.cc.cc`:

    # before:
    $ nix path-info -Sh $(nix-build -A pkgsCross.mingwW64.gcc12Stdenv.cc.cc) | unnix
    /<<NIX>>/x86_64-w64-mingw32-stage-final-gcc-debug-12.1.0           2.5G

    # after:
    $ nix path-info -Sh $(nix-build -A pkgsCross.mingwW64.gcc12Stdenv.cc.cc) | unnix
    /<<NIX>>/x86_64-w64-mingw32-stage-final-gcc-12.1.0         1.5G

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

@@ -24,9 +24,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -86,7 +83,7 @@ let majorVersion = "10";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -231,9 +228,11 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
-
-  installTargets = optional stripped "install-strip";
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
@@ -274,8 +273,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -24,9 +24,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -92,7 +89,7 @@ let majorVersion = "11";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -239,9 +236,11 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
-
-  installTargets = optional stripped "install-strip";
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
@@ -282,8 +281,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -24,9 +24,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -89,7 +86,7 @@ let majorVersion = "12";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -234,9 +231,11 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
-
-  installTargets = optional stripped "install-strip";
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
@@ -277,8 +276,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -28,9 +28,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform == stdenv.buildPlatform
-          && stdenv.targetPlatform == stdenv.hostPlatform
 , gnused ? null
 , buildPackages
 }:
@@ -124,7 +121,7 @@ in
 assert x11Support -> (filter (x: x == null) ([ gtk2 libart_lgpl ] ++ xlibs)) == [];
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -238,12 +235,14 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   doCheck = false; # requires a lot of tools, causes a dependency cycle for stdenv
 
-  installTargets = optional stripped "install-strip";
-
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
 
@@ -297,8 +296,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -28,9 +28,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform == stdenv.buildPlatform
-          && stdenv.targetPlatform == stdenv.hostPlatform
 , gnused ? null
 , buildPackages
 }:
@@ -140,7 +137,7 @@ in
 assert x11Support -> (filter (x: x == null) ([ gtk2 libart_lgpl ] ++ xlibs)) == [];
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -258,12 +255,14 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   doCheck = false; # requires a lot of tools, causes a dependency cycle for stdenv
 
-  installTargets = optional stripped "install-strip";
-
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
 
@@ -316,8 +315,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -31,9 +31,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -121,7 +118,7 @@ in
 assert x11Support -> (filter (x: x == null) ([ gtk2 libart_lgpl ] ++ xlibs)) == [];
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -270,12 +267,14 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   doCheck = false; # requires a lot of tools, causes a dependency cycle for stdenv
 
-  installTargets = optional stripped "install-strip";
-
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
 
@@ -328,8 +327,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -21,9 +21,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -94,7 +91,7 @@ let majorVersion = "7";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -237,12 +234,14 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   doCheck = false; # requires a lot of tools, causes a dependency cycle for stdenv
 
-  installTargets = optional stripped "install-strip";
-
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
 
@@ -282,8 +281,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -21,9 +21,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -78,7 +75,7 @@ let majorVersion = "8";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -218,9 +215,11 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
-
-  installTargets = optional stripped "install-strip";
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
@@ -261,8 +260,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

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

@@ -24,9 +24,6 @@
 , libcCross ? null
 , threadsCross ? null # for MinGW
 , crossStageStatic ? false
-, # Strip kills static libs of other archs (hence no cross)
-  stripped ? stdenv.hostPlatform.system == stdenv.buildPlatform.system
-          && stdenv.targetPlatform.system == stdenv.hostPlatform.system
 , gnused ? null
 , cloog # unused; just for compat with gcc4, as we override the parameter on some places
 , buildPackages
@@ -89,7 +86,7 @@ let majorVersion = "9";
 in
 
 stdenv.mkDerivation ({
-  pname = "${crossNameAddon}${name}${if stripped then "" else "-debug"}";
+  pname = "${crossNameAddon}${name}";
   inherit version;
 
   builder = ../builder.sh;
@@ -233,9 +230,11 @@ stdenv.mkDerivation ({
     (targetPlatform == hostPlatform && hostPlatform == buildPlatform)
     (if profiledCompiler then "profiledbootstrap" else "bootstrap");
 
-  dontStrip = !stripped;
-
-  installTargets = optional stripped "install-strip";
+  inherit
+    (import ../common/strip-attributes.nix { inherit stdenv; })
+    stripDebugList
+    stripDebugListTarget
+    preFixup;
 
   # https://gcc.gnu.org/install/specific.html#x86-64-x-solaris210
   ${if hostPlatform.system == "x86_64-solaris" then "CC" else null} = "gcc -m64";
@@ -276,8 +275,7 @@ stdenv.mkDerivation ({
   meta = {
     homepage = "https://gcc.gnu.org/";
     license = lib.licenses.gpl3Plus;  # runtime support libraries are typically LGPLv3+
-    description = "GNU Compiler Collection, version ${version}"
-      + (if stripped then "" else " (with debugging info)");
+    description = "GNU Compiler Collection, version ${version}";
 
     longDescription = ''
       The GNU Compiler Collection includes compiler front ends for C, C++,

pkgs/development/compilers/gcc/builder.sh

@@ -147,11 +147,6 @@ if test "$noSysDirs" = "1"; then
     fi
 fi
 
-if [ -n "${targetConfig-}" ]; then
-    # if stripping gcc, include target directory too
-    stripDebugList="${stripDebugList-lib lib32 lib64 libexec bin sbin} $targetConfig"
-fi
-
 eval "$oldOpts"
 
 providedPreConfigure="$preConfigure";

pkgs/development/compilers/gcc/common/strip-attributes.nix

@@ -0,0 +1,53 @@
+{ stdenv }:
+
+{
+  # Note [Cross-compiler stripping]
+  # gcc requires delicate stripping as it installs ELF files for both
+  # HOST and TARGET platforms. It requires according strip tool otherwise
+  # strip could remove sections it's not aware of.
+  # Example ARM breakage by x86_64 strip: https://bugs.gentoo.org/697428
+  #
+  # Let's recap the file layout for directories with object files for a
+  # cross-compiler (host != target):
+  # `- bin: HOST
+  #    lib/*.{a,o}: HOST
+  #      `- gcc/<TARGET>/<VERSION>/*.{a,o}: TARGET
+  #                               `- plugin/: HOST
+  #  `- lib{,32,64,x32}: symlink to lib or identical layout
+  #  `- libexec/: HOST
+  #  `- <TARGET>/: TARGET
+  #
+  # (host == target) has identical directory layout.
+
+  # The rest of stripDebugList{Host,Target} will be populated in
+  # postInstall.
+  stripDebugList = [ "bin" "libexec" ];
+  stripDebugListTarget = [ stdenv.targetPlatform.config ];
+
+  preFixup = ''
+    # Populate most delicated lib/ part of stripDebugList{,Target}
+    updateDebugListPaths() {
+      local oldOpts
+      oldOpts="$(shopt -p nullglob)" || true
+      shopt -s nullglob
+
+      pushd $out
+
+      local -ar hostFiles=(
+        lib{,32,64}/*.{a.o}
+        lib{,32,64}/gcc/${stdenv.targetPlatform.config}/*/plugin
+      )
+      local -ar targetFiles=(
+        lib{,32,64}/gcc/${stdenv.targetPlatform.config}/*/*.{a.o}
+      )
+
+      stripDebugList="$stripDebugList ''${hostFiles[*]}"
+      stripDebugListTarget="$stripDebugListTarget ''${targetFiles[*]}"
+
+      popd
+
+      eval "$oldOpts"
+    }
+    updateDebugListPaths
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -12955,9 +12955,9 @@ with pkgs;
   clangMultiStdenv = overrideCC stdenv buildPackages.clang_multi;
   multiStdenv = if stdenv.cc.isClang then clangMultiStdenv else gccMultiStdenv;
 
-  gcc_debug = lowPrio (wrapCC (gcc.cc.override {
-    stripped = false;
-  }));
+  gcc_debug = lowPrio (wrapCC (gcc.cc.overrideAttrs (_: {
+    dontStrip = true;
+  })));
 
   gccCrossLibcStdenv = overrideCC stdenv buildPackages.gccCrossStageStatic;