gnattools build machinery uses just-build xgcc and xg++ as $(CC) and
$(CXX) in native builds. However, if C and C++ languages are not
enabled, it won't find them. So, enable C and C++ if Ada is enabled.
Most of the time, this is probably no big deal: C is always enabled
anyway, and C++ is already enabled for bootstraps.
We need not enable those for cross builds, however. At first I just
took the logic from gnattools/configure, but found it to be lacking:
it would use the just-built tools even in cross-back settings, whose
tools just built for the host would not run on the build machine. So
I've narrowed down the test to rely on autoconf-detected cross-ness
(build->host only), but also to ensure that host matches build, and
that target matches host.
I've considered sourcing ada/config-lang.in from within
gnattools/configure, and testing lang_requires as set by it, so as to
avoid a duplication of tests that ought to remain in sync, but decided
it would be too fragile, as ada/config-lang.in does not expect srcdir
to refer to gnattools.
Please let me know if there are objections to this change in the next
few days, e.g., if enabling C and C++ for an Ada-only build is too
onerous. It is certainly possible to rework gnattools build machinery
so that it uses CC and CXX as detected by the top-level configure if we
can't find xgcc and xg++ in ../gcc. At least in cross builds, we
already require build-time Ada tools to have the same version as that
we're cross-building, so we might as well use preexisting gcc and g++
under the same requirements.
for gcc/ada/gcc-interface/ChangeLog
PR ada/81878
* config-lang.in (lang_requires): Set to "c c++" when
gnattools wants it.
for gnattools/ChangeLog
PR ada/81878
* configure.ac (default_gnattools_target): Do not mistake
just-built host tools as native in cross-back toolchains.
* configure: Rebuilt.
---
gcc/ada/gcc-interface/config-lang.in | 9 +++++++++
gnattools/configure | 32 ++++++++++++++++++++++----------
gnattools/configure.ac | 30 +++++++++++++++++++++---------
3 files changed, 52 insertions(+), 19 deletions(-)
diff --git a/gcc/ada/gcc-interface/config-lang.in
b/gcc/ada/gcc-interface/config-lang.in
index 5dc77df282ce..8eacf7bb870e 100644
--- a/gcc/ada/gcc-interface/config-lang.in
+++ b/gcc/ada/gcc-interface/config-lang.in
@@ -34,6 +34,15 @@ gtfiles="\$(srcdir)/ada/gcc-interface/ada-tree.h
\$(srcdir)/ada/gcc-interface/gi
outputs="ada/gcc-interface/Makefile ada/Makefile"
+# gnattools native builds use both $(CC) and $(CXX), see PR81878.
+# This is not too onerous: C is always enabled anyway, and C++ is
+# always enabled for bootstrapping. Use here the same logic used in
+# gnattools/configure to decide whether to use -native or -cross tools
+# for the build.
+if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
+ lang_requires="c c++"
+fi
+
target_libs="target-libada"
lang_dirs="gnattools"
diff --git a/gnattools/configure b/gnattools/configure
index ccb512e39b6b..c2d755b723a9 100755
--- a/gnattools/configure
+++ b/gnattools/configure
@@ -584,6 +584,7 @@ PACKAGE_URL=
ac_unique_file="Makefile.in"
ac_subst_vars='LTLIBOBJS
LIBOBJS
+default_gnattools_target
warn_cflags
OBJEXT
EXEEXT
@@ -595,7 +596,6 @@ CC
ADA_CFLAGS
EXTRA_GNATTOOLS
TOOLS_TARGET_PAIRS
-default_gnattools_target
LN_S
target_noncanonical
host_noncanonical
@@ -2050,15 +2050,6 @@ $as_echo "no, using $LN_S" >&6; }
fi
-# Determine what to build for 'gnattools'
-if test $build = $target ; then
- # Note that build=target is almost certainly the wrong test; FIXME
- default_gnattools_target="gnattools-native"
-else
- default_gnattools_target="gnattools-cross"
-fi
-
-
# Target-specific stuff (defaults)
TOOLS_TARGET_PAIRS=
@@ -2134,6 +2125,8 @@ esac
# From user or toplevel makefile.
+# This is testing the CC passed from the toplevel Makefile, not the
+# one we will select below.
ac_ext=c
ac_cpp='$CPP $CPPFLAGS'
ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
@@ -2929,6 +2922,25 @@ if test "x$GCC" = "xyes"; then
fi
+# Determine what to build for 'gnattools'. Test after the above,
+# because testing for CC sets the final value of cross_compiling, even
+# if we end up using a different CC. We want to build
+# gnattools-native when: (a) this is a native build, i.e.,
+# cross_compiling=no, otherwise we know we cannot run binaries
+# produced by the toolchain used for the build, not even the binaries
+# created within ../gcc/; (b) build and host are the same, otherwise
+# this is to be regarded as a cross build environment even if it seems
+# that we can run host binaries; (c) host and target are the same,
+# otherwise the tools in ../gcc/ generate code for a different
+# platform. If you change this test, be sure to adjust
+# ../gcc/ada/gcc-interface/config-lang.in as well.
+if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
+ default_gnattools_target="gnattools-native"
+else
+ default_gnattools_target="gnattools-cross"
+fi
+
+
# Output: create a Makefile.
ac_config_files="$ac_config_files Makefile"
diff --git a/gnattools/configure.ac b/gnattools/configure.ac
index 0a94224a5362..40d015ce8b0d 100644
--- a/gnattools/configure.ac
+++ b/gnattools/configure.ac
@@ -51,15 +51,6 @@ ACX_NONCANONICAL_TARGET
# Need to pass this down for now :-P
AC_PROG_LN_S
-# Determine what to build for 'gnattools'
-if test $build = $target ; then
- # Note that build=target is almost certainly the wrong test; FIXME
- default_gnattools_target="gnattools-native"
-else
- default_gnattools_target="gnattools-cross"
-fi
-AC_SUBST([default_gnattools_target])
-
# Target-specific stuff (defaults)
TOOLS_TARGET_PAIRS=
AC_SUBST(TOOLS_TARGET_PAIRS)
@@ -135,6 +126,8 @@ esac
# From user or toplevel makefile.
AC_SUBST(ADA_CFLAGS)
+# This is testing the CC passed from the toplevel Makefile, not the
+# one we will select below.
AC_PROG_CC
warn_cflags=
if test "x$GCC" = "xyes"; then
@@ -142,6 +135,25 @@ if test "x$GCC" = "xyes"; then
fi
AC_SUBST(warn_cflags)
+# Determine what to build for 'gnattools'. Test after the above,
+# because testing for CC sets the final value of cross_compiling, even
+# if we end up using a different CC. We want to build
+# gnattools-native when: (a) this is a native build, i.e.,
+# cross_compiling=no, otherwise we know we cannot run binaries
+# produced by the toolchain used for the build, not even the binaries
+# created within ../gcc/; (b) build and host are the same, otherwise
+# this is to be regarded as a cross build environment even if it seems
+# that we can run host binaries; (c) host and target are the same,
+# otherwise the tools in ../gcc/ generate code for a different
+# platform. If you change this test, be sure to adjust
+# ../gcc/ada/gcc-interface/config-lang.in as well.
+if test "x$cross_compiling/$build/$host" = "xno/$host/$target" ; then
+ default_gnattools_target="gnattools-native"
+else
+ default_gnattools_target="gnattools-cross"
+fi
+AC_SUBST([default_gnattools_target])
+
# Output: create a Makefile.
AC_CONFIG_FILES([Makefile])
--
Alexandre Oliva, freedom fighter https://FSFLA.org/blogs/lxo
Be the change, be Free! FSF Latin America board member
GNU Toolchain Engineer Free Software Evangelist
Hay que enGNUrecerse, pero sin perder la terGNUra jamás-GNUChe
