gcc: build with --enable-default-pie configure option

Rather than implementing this at the wrapper level (which has been
attempted but not merged in # 252310 and # 205031), configuring GCC
directly with --enable-default-pie is simple and matches mainstream
distribution practices. Packages that cannot build with PIE can
explicitly pass -no-pie when needed, and mostly already do
due to the prevalence of GCCs built with this flag.

Requires followup to decide what to do with "pie" flag.

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

@@ -20,6 +20,7 @@
   enablePlugin,
   disableGdbPlugin ? !enablePlugin,
   enableShared,
+  enableDefaultPie,
   targetPrefix,
 
   langC,
@@ -279,6 +280,9 @@ let
       "libat_cv_have_ifunc=no"
       "--disable-gnu-indirect-function"
     ]
+    ++ lib.optionals enableDefaultPie [
+      "--enable-default-pie"
+    ]
     ++ lib.optionals langJit [
       "--enable-host-shared"
     ]

pkgs/development/compilers/gcc/default.nix

@@ -19,6 +19,7 @@
   cargo,
   staticCompiler ? false,
   enableShared ? stdenv.targetPlatform.hasSharedLibraries,
+  enableDefaultPie ? true,
   enableLTO ? stdenv.hostPlatform.hasSharedLibraries,
   texinfo ? null,
   perl ? null, # optional, for texi2pod (then pod2man)
@@ -137,6 +138,7 @@ let
       darwin
       disableBootstrap
       disableGdbPlugin
+      enableDefaultPie
       enableLTO
       enableMultilib
       enablePlugin

pkgs/development/compilers/gcc/ng/common/gcc/default.nix

@@ -193,6 +193,7 @@ stdenv.mkDerivation (finalAttrs: {
     "--disable-multilib"
     "--disable-nls"
     "--disable-shared"
+    "--enable-default-pie"
     "--enable-languages=${
       lib.concatStrings (
         lib.intersperse "," (

pkgs/development/libraries/gcc/libgcc/default.nix

@@ -54,9 +54,10 @@ stdenv.mkDerivation (finalAttrs: {
     # Drop in libiberty, as external builds are not expected
     cd "$buildRoot"
     (
-      mkdir -p build-${stdenv.buildPlatform.config}/libiberty/
+      mkdir -p "build-${stdenv.buildPlatform.config}/libiberty/pic"
-      cd build-${stdenv.buildPlatform.config}/libiberty/
+      cd "build-${stdenv.buildPlatform.config}/libiberty/"
-      ln -s ${buildPackages.libiberty}/lib/libiberty.a ./
+      ln -s "${buildPackages.libiberty}/lib/libiberty.a" ./
+      ln -s "${buildPackages.libiberty}/lib/libiberty_pic.a" pic/libiberty.a
     )
     mkdir -p "$buildRoot/gcc"
     cd "$buildRoot/gcc"

pkgs/stdenv/linux/default.nix

@@ -425,6 +425,11 @@ assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
               #   ...-binutils-patchelfed-ld-2.40/bin/ld: ...-xgcc-13.0.0/libexec/gcc/x86_64-unknown-linux-gnu/13.0.1/liblto_plugin.so:
               #     error loading plugin: ...-bootstrap-tools/lib/libpthread.so.0: undefined symbol: __libc_vfork, version GLIBC_PRIVATE
               enableLTO = false;
+
+              # relocatable libs may not be available in the bootstrap
+              # which will cause compilation to fail with
+              # configure: error: C compiler cannot create executables
+              enableDefaultPie = false;
             }
           )).overrideAttrs
             (a: {