https://gcc.gnu.org/g:2e2959e1447562b11093474a0ae7a004e523335d

commit 2e2959e1447562b11093474a0ae7a004e523335d
Author: Olivier Hainque <[email protected]>
Date:   Sat Dec 13 04:10:57 2025 -0300

    Introduce x86_64-linux-gnum32
    
    Enable a 32-bit "native" toolchain on x86_64-linux-gnu, i.e., one that
    targets -m32 by default, despite supporting and potentially running in
    64-bit mode.  Adjust libada and gnattools build machinery to support
    this configuration in both bootstrap and non-bootstrap modes.
    
    Co-Authored-By: Alexandre Oliva <[email protected]>
    
    for  gcc/ChangeLog
    
            * config.gcc [x86_64-*-*]: Match *m32 target, default to m32
            abi.  Accept 32 or m32 for --with-abi.
    
    for  gcc/ada/ChangeLog
    
            * gcc-interface/Make-lang.in (m32_target): Set.
            (not_m32_target, native_target, native_gnattools1): Set.
            (ADA_TOOLS_FLAGS_TO_PASS, gnattools): Handle x86_64 natives
            defaulting to -m32 as cross for gnattools.
            * gcc-interface/Makefile.in (target_cpu): Set to i686 for
            x86_64 configurations defaulting to -m32.
    
    for  gnattools/ChangeLog
    
            * configure.ac (default_gnattools_target): Use gnattools-cross
            when not bootstrapping x86_64 configurations defaulting to
            -m32.
            * configure: Rebuild.

Diff:
---
 gcc/ada/gcc-interface/Make-lang.in | 25 +++++++++++++++++++------
 gcc/ada/gcc-interface/Makefile.in  |  7 +++++++
 gcc/config.gcc                     | 25 +++++++++++++++++++++++++
 gnattools/configure                | 10 ++++++++++
 gnattools/configure.ac             | 10 ++++++++++
 5 files changed, 71 insertions(+), 6 deletions(-)

diff --git a/gcc/ada/gcc-interface/Make-lang.in 
b/gcc/ada/gcc-interface/Make-lang.in
index e768ef60ddf7..c264caa4c94e 100644
--- a/gcc/ada/gcc-interface/Make-lang.in
+++ b/gcc/ada/gcc-interface/Make-lang.in
@@ -192,10 +192,20 @@ GNATLS_FOR_HOST   = $(subst gnatmake,gnatls,$(GNATMAKE))
 
 # There are too many Ada sources to check against here.  Let's
 # always force the recursive make.
+
+# A native x86_64 compiler defaulting to -m32 is not suitable to build
+# 64bit host tools.  Arrange to build the tools with the base compiler
+# in this case, as we do for cross configurations.
+
+m32_target=$(filter x86_64%m32, $(target))
+not_m32_target=$(if $(m32_target),,$(target))
+
 ifeq ($(build), $(host))
-  ifeq ($(host), $(target))
-    # This is a regular native. So use the compiler from our current build
-    # tree.
+  native_target=$(filter $(host), $(target))
+
+  ifneq ($(and $(native_target), $(not_m32_target)),)
+    # This is a regular native. Use the compiler from our
+    # current build tree.
     ADA_TOOLS_FLAGS_TO_PASS=\
         CC="../../xgcc -B../../" \
         CXX="$(CXX)" \
@@ -205,8 +215,8 @@ ifeq ($(build), $(host))
         GNATLINK="../../gnatlink" \
         GNATBIND="../../gnatbind"
   else
-    # This is a regular cross compiler. Use the native compiler to compile
-    # the tools.
+    # This is a regular cross compiler or a 64bit native defaulting to -m32.
+    # Use the base native compiler to compile the tools.
 
     # put the host RTS dir first in the PATH to hide the default runtime
     # files that are among the sources
@@ -792,8 +802,11 @@ gnatbind$(exeext): ada/b_gnatb.o $(CONFIG_H) 
$(GNATBIND_OBJS) $(EXTRA_HOST_OBJS)
        +$(GCC_LINK) -o $@ $(CFLAGS) ada/b_gnatb.o $(GNATBIND_OBJS) 
$(EXTRA_HOST_OBJS) ggc-none.o libcommon-target.a $(LIBS) $(SYSLIBS) $(GNATLIB)
 
 # use target-gcc target-gnatmake target-gnatbind target-gnatlink
+
+native_gnattools1=$(if $(not_m32_target),gnattools1,gnattools1-re)
+
 gnattools: $(CONFIG_H) prefix.o force
-       $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) gnattools1
+       $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) $(native_gnattools1)
        $(MAKE) -C ada $(ADA_TOOLS_FLAGS_TO_PASS) gnattools2
 
 regnattools:
diff --git a/gcc/ada/gcc-interface/Makefile.in 
b/gcc/ada/gcc-interface/Makefile.in
index f37893e93fee..2eadf996a1a7 100644
--- a/gcc/ada/gcc-interface/Makefile.in
+++ b/gcc/ada/gcc-interface/Makefile.in
@@ -358,6 +358,13 @@ ifeq ($(strip $(filter-out x86_64 linux-gnux32%, 
$(target_cpu) $(target_os))),)
   endif
 endif
 
+# The x86_64-*m32 compilers are x86_64 compilers defaulting to -m32
+ifeq ($(strip $(filter-out x86_64 %m32, $(target_cpu) $(target_os))),)
+  ifneq ($(strip $(MULTISUBDIR)),/64)
+    target_cpu:=i686
+  endif
+endif
+
 # Configuration of host tools
 
 # Under linux, host tools need to be linked with -ldl
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 836cdff6317b..a94bb0161dcf 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -677,6 +677,28 @@ i[34567]86-*-*)
 x86_64-*-darwin*)
        ;;
 x86_64-*-*)
+        # Pick a default with_abi and with_multilib_list for m32
+        # restricted toolchains
+        case ${target} in
+        *m32)
+               case ${with_abi} in
+               "" | 32 | m32)
+                       with_abi=m32
+                       ;;
+               *)
+                       echo "Invalid --with-abi=$with_abi for m32 target"
+                       exit 1
+              esac
+              case ${with_multilib_list} in
+              default | *m32*)
+                       ;;
+              *)
+                       echo "Invalid multilib list for m32 target"
+                       exit 1
+              esac
+              ;;
+       esac
+
        case ${with_abi} in
        "")
                if test "x$with_multilib_list" = xmx32; then
@@ -691,6 +713,9 @@ x86_64-*-*)
        x32 | mx32)
                tm_file="i386/biarchx32.h ${tm_file}"
                ;;
+       32 | m32)
+               tm_defines="${tm_defines} TARGET_BI_ARCH=1"
+               ;;
        *)
                echo "Unknown ABI used in --with-abi=$with_abi"
                exit 1
diff --git a/gnattools/configure b/gnattools/configure
index b3b6aab1b72e..a089a034ca16 100755
--- a/gnattools/configure
+++ b/gnattools/configure
@@ -3683,6 +3683,16 @@ fi
 # ../gcc/ada/gcc-interface/config-lang.in as well.
 if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
   default_gnattools_target="gnattools-native"
+  # When natively-building x86_64-*-gnum32 tools without bootstrap,
+  # use the native toolchain to build gnattools, expecting its
+  # libraries to be compatible with whichever multilib was used to
+  # build other tools.  This requires the compiler being built to be
+  # gnatbind-compatible with the one used for the build.
+  case $enable_bootstrap/$target in
+    no/x86_64-*-gnum32)
+      default_gnattools_target="gnattools-cross"
+      ;;
+  esac
 else
   default_gnattools_target="gnattools-cross"
 fi
diff --git a/gnattools/configure.ac b/gnattools/configure.ac
index ff07179b3ba8..adbdc8996db6 100644
--- a/gnattools/configure.ac
+++ b/gnattools/configure.ac
@@ -125,6 +125,16 @@ AC_SUBST(LD_PICFLAG)
 # ../gcc/ada/gcc-interface/config-lang.in as well.
 if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
   default_gnattools_target="gnattools-native"
+  # When natively-building x86_64-*-gnum32 tools without bootstrap,
+  # use the native toolchain to build gnattools, expecting its
+  # libraries to be compatible with whichever multilib was used to
+  # build other tools.  This requires the compiler being built to be
+  # gnatbind-compatible with the one used for the build.
+  case $enable_bootstrap/$target in
+    no/x86_64-*-gnum32)
+      default_gnattools_target="gnattools-cross"
+      ;;
+  esac
 else
   default_gnattools_target="gnattools-cross"
 fi

Reply via email to