Add TEST_CC and TEST_CXX support

Support testing glibc build with a different C compiler or a different
C++ compiler with

$ ../glibc-VERSION/configure TEST_CC="gcc-6.4.1" TEST_CXX="g++-6.4.1"

1. Add LIBC_TRY_CC_AND_TEST_CC_OPTION, LIBC_TRY_CC_AND_TEST_CC_COMMAND
and LIBC_TRY_CC_AND_TEST_LINK to test both CC and TEST_CC.
2. Add check and xcheck targets to Makefile.in and override build compiler
options with ones from TEST_CC and TEST_CXX.

Tested on Fedora 41/x86-64:

1. Building with GCC 14.2.1 and testing with GCC 6.4.1 and GCC 11.2.1.
2. Building with GCC 15 and testing with GCC 6.4.1.

Support for GCC versions older than GCC 6.2 may need to change the test
sources.  Other targets may need to update configure.ac under sysdeps and
modify Makefile.in to override target build compiler options.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Sam James <sam@gentoo.org>

1 files changed, 293 insertions, 36 deletions

diff --git a/configure b/configure
index e99c0d23af..fbfe849474 100755
--- a/configure
+++ b/configure
@@ -620,6 +620,9 @@ DEFINES
 static_nss
 profile
 libc_cv_multidir
+libc_cv_test_x86_have_amx_tile
+test_enable_cet
+libc_cv_test_cc_mprefer_vector_width
 shared
 static
 ldd_rewrite_script
@@ -641,15 +644,21 @@ fortify_source
 no_fortify_source
 libc_cv_fortify_source
 enable_fortify_source
+libc_cv_test_supported_fortify_source
 have_selinux
 have_libcap
 have_libaudit
 LIBGD
+libc_cv_test_cc_wimplicit_fallthrough
 libc_cv_cc_loop_to_function
+libc_cv_test_cc_signaling_nans
 libc_cv_cc_submachine
 libc_cv_cc_nofma
+libc_cv_test_wno_ignored_attributes
+libc_cv_test_mtls_descriptor
 libc_cv_has_glob_dat
 libc_cv_fpie
+libc_cv_test_static_pie
 libc_cv_z_execstack
 ASFLAGS_config
 libc_cv_cc_with_libunwind
@@ -704,12 +713,14 @@ man_pages_version
 rtld_early_cflags
 extra_nonshared_cflags
 sysheaders
+TEST_CXX
 ac_ct_CXX
 CXXFLAGS
 CXX
 CPP
 cross_compiling
 BUILD_CC
+TEST_CC
 OBJEXT
 ac_ct_CC
 CPPFLAGS
@@ -819,10 +830,12 @@ CFLAGS
 LDFLAGS
 LIBS
 CPPFLAGS
+TEST_CC
 CPP
 CXX
 CXXFLAGS
-CCC'
+CCC
+TEST_CXX'
 ac_subdirs_all=''
 
 # Initialize some variables set by options.
@@ -1523,9 +1536,11 @@ Some influential environment variables:
   LIBS        libraries to pass to the linker, e.g. -l<library>
   CPPFLAGS    (Objective) C/C++ preprocessor flags, e.g. -I<include dir> if
               you have headers in a nonstandard directory <include dir>
+  TEST_CC     C compiler for testing
   CPP         C preprocessor
   CXX         C++ compiler command
   CXXFLAGS    C++ compiler flags
+  TEST_CXX    C++ compiler for testing
 
 Use these variables to override the choices made by 'configure' or to help
 it to find libraries and programs with nonstandard names/locations.
@@ -3806,6 +3821,10 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+
+if test -z "$TEST_CC"; then
+  TEST_CC="$CC"
+fi
 if test $host != $build; then
   for ac_prog in gcc cc
 do
@@ -4280,6 +4299,14 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
+
+if test -z "$TEST_CXX"; then
+  saved_CXX=
+  TEST_CXX="$CXX"
+else
+  saved_CXX="$CXX"
+  CXX="$TEST_CXX"
+fi
 # It's useless to us if it can't link programs (e.g. missing -lstdc++).
 
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $CXX can link programs" >&5
@@ -4357,6 +4384,9 @@ if test $libc_cv_cxx_link_ok != yes
 then :
   CXX=
 fi
+if test -n "$saved_CXX"; then
+  CXX="$saved_CXX"
+fi
 
 if test "`cd $srcdir; pwd -P`" = "`pwd -P`"; then
   as_fn_error $? "you must configure in a separate build directory" "$LINENO" 5
@@ -7103,6 +7133,7 @@ printf "%s\n" "$libc_linker_feature" >&6; }
 config_vars="$config_vars
 have-no-dynamic-linker = $libc_cv_no_dynamic_linker"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -static-pie" >&5
 printf %s "checking for -static-pie... " >&6; }
 if test ${libc_cv_static_pie+y}
@@ -7120,15 +7151,49 @@ then :
 else case e in #(
   e) libc_cv_static_pie=no ;;
 esac
-fi
- ;;
+fi ;;
 esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_static_pie" >&5
 printf "%s\n" "$libc_cv_static_pie" >&6; }
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_static_pie=$libc_cv_static_pie
+else
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -static-pie in testing" >&5
+printf %s "checking for -static-pie in testing... " >&6; }
+if test ${libc_cv_test_static_pie+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if { ac_try='${CC-cc} -static-pie -xc /dev/null -S -o /dev/null'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+then :
+  libc_cv_test_static_pie=yes
+else case e in #(
+  e) libc_cv_test_static_pie=no
+ ;;
+esac
+fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_static_pie" >&5
+printf "%s\n" "$libc_cv_test_static_pie" >&6; }
+
+CC="$saved_CC"
+
+fi
+
 config_vars="$config_vars
 have-static-pie = $libc_cv_static_pie"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -fpie" >&5
 printf %s "checking for -fpie... " >&6; }
 if test ${libc_cv_fpie+y}
@@ -7190,70 +7255,144 @@ fi
 printf "%s\n" "$libc_cv_has_glob_dat" >&6; }
 
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for tls descriptor support" >&5
-printf %s "checking for tls descriptor support... " >&6; }
-if test ${libc_cv_mtls_descriptor+y}
-then :
-  printf %s "(cached) " >&6
-else case e in #(
-  e) cat > conftest.c <<EOF
+conftest_code="
 __thread int i;
 void foo (void)
 {
   i = 10;
 }
+"
+
+cat > conftest.c <<EOF
+$conftest_code
 EOF
-if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -fPIC -mtls-dialect=$mtls_descriptor -nostdlib -nostartfiles
-		   -shared conftest.c -o conftest 1>&5'
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for tls descriptor support" >&5
+printf %s "checking for tls descriptor support... " >&6; }
+if test ${libc_cv_mtls_descriptor+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)   if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -fPIC -mtls-dialect=$mtls_descriptor -nostdlib -nostartfiles -shared conftest.c -o conftest 1>&5'
   { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
   (eval $ac_try) 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; }
-then
-  libc_cv_mtls_descriptor=$mtls_descriptor
-else
-  libc_cv_mtls_descriptor=no
-fi
-rm -f conftest* ;;
+  then
+    libc_cv_mtls_descriptor=$mtls_descriptor
+  else
+    libc_cv_mtls_descriptor=no
+  fi
+ ;;
 esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_mtls_descriptor" >&5
 printf "%s\n" "$libc_cv_mtls_descriptor" >&6; }
-config_vars="$config_vars
-have-mtls-descriptor = $libc_cv_mtls_descriptor"
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_mtls_descriptor=$libc_cv_mtls_descriptor
+else
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if -Wno-ignored-attributes is required for aliases" >&5
-printf %s "checking if -Wno-ignored-attributes is required for aliases... " >&6; }
-if test ${libc_cv_wno_ignored_attributes+y}
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for tls descriptor support in testing" >&5
+printf %s "checking for tls descriptor support in testing... " >&6; }
+if test ${libc_cv_test_mtls_descriptor+y}
 then :
   printf %s "(cached) " >&6
 else case e in #(
-  e) cat > conftest.c <<EOF
+  e)       if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -fPIC -mtls-dialect=$mtls_descriptor -nostdlib -nostartfiles -shared conftest.c -o conftest 1>&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+      then
+	libc_cv_test_mtls_descriptor=$mtls_descriptor
+      else
+	libc_cv_test_mtls_descriptor=no
+      fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_mtls_descriptor" >&5
+printf "%s\n" "$libc_cv_test_mtls_descriptor" >&6; }
+
+CC="$saved_CC"
+
+fi
+rm -f conftest*
+config_vars="$config_vars
+have-mtls-descriptor = $libc_cv_mtls_descriptor"
+
+
+conftest_code="
 void __foo (void)
 {
 }
 extern __typeof (__foo) foo __attribute__ ((weak, alias ("__foo")));
 extern __typeof (__foo) bar __attribute__ ((weak, alias ("foo")));
+"
+
+cat > conftest.c <<EOF
+$conftest_code
 EOF
-libc_cv_wno_ignored_attributes=""
-if ! { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -Werror -c conftest.c'
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if -Wno-ignored-attributes is required for aliases" >&5
+printf %s "checking if -Wno-ignored-attributes is required for aliases... " >&6; }
+if test ${libc_cv_wno_ignored_attributes+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)   if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -c -Werror -Wno-ignored-attributes conftest.c -o conftest 1>&5'
   { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
   (eval $ac_try) 2>&5
   ac_status=$?
   printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
   test $ac_status = 0; }; }
-then
-  libc_cv_wno_ignored_attributes="-Wno-ignored-attributes"
-fi
-rm -f conftest* ;;
+  then
+    libc_cv_wno_ignored_attributes="-Wno-ignored-attributes"
+  else
+    libc_cv_wno_ignored_attributes=
+  fi
+ ;;
 esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_wno_ignored_attributes" >&5
 printf "%s\n" "$libc_cv_wno_ignored_attributes" >&6; }
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_wno_ignored_attributes=$libc_cv_wno_ignored_attributes
+else
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if -Wno-ignored-attributes is required for aliases in testing" >&5
+printf %s "checking if -Wno-ignored-attributes is required for aliases in testing... " >&6; }
+if test ${libc_cv_test_wno_ignored_attributes+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)       if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -c -Werror -Wno-ignored-attributes conftest.c -o conftest 1>&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+      then
+	libc_cv_test_wno_ignored_attributes="-Wno-ignored-attributes"
+      else
+	libc_cv_test_wno_ignored_attributes=
+      fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_wno_ignored_attributes" >&5
+printf "%s\n" "$libc_cv_test_wno_ignored_attributes" >&6; }
+
+CC="$saved_CC"
+
+fi
+rm -f conftest*
 config_vars="$config_vars
 config-cflags-wno-ignored-attributes = $libc_cv_wno_ignored_attributes"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether cc puts quotes around section names" >&5
 printf %s "checking whether cc puts quotes around section names... " >&6; }
 if test ${libc_cv_have_section_quotes+y}
@@ -7405,6 +7544,7 @@ printf "%s\n" "$libc_cv_cc_submachine" >&6; }
 fi
 
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for compiler option that -fsignaling-nans" >&5
 printf %s "checking for compiler option that -fsignaling-nans... " >&6; }
 if test ${libc_cv_cc_signaling_nans+y}
@@ -7422,15 +7562,48 @@ then :
 else case e in #(
   e) libc_cv_cc_signaling_nans= ;;
 esac
-fi
- ;;
+fi ;;
 esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_signaling_nans" >&5
 printf "%s\n" "$libc_cv_cc_signaling_nans" >&6; }
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_cc_signaling_nans=$libc_cv_cc_signaling_nans
+else
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for compiler option that -fsignaling-nans in testing" >&5
+printf %s "checking for compiler option that -fsignaling-nans in testing... " >&6; }
+if test ${libc_cv_test_cc_signaling_nans+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if { ac_try='${CC-cc} -Werror -fsignaling-nans -xc /dev/null -S -o /dev/null'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+then :
+  libc_cv_test_cc_signaling_nans=-fsignaling-nans
+else case e in #(
+  e) libc_cv_test_cc_signaling_nans= ;;
+esac
+fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_cc_signaling_nans" >&5
+printf "%s\n" "$libc_cv_test_cc_signaling_nans" >&6; }
+
+CC="$saved_CC"
+
+fi
+
 config_vars="$config_vars
 config-cflags-signaling-nans = $libc_cv_cc_signaling_nans"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking if $CC accepts -fno-tree-loop-distribute-patterns with \
 __attribute__ ((__optimize__))" >&5
 printf %s "checking if $CC accepts -fno-tree-loop-distribute-patterns with \
@@ -7465,6 +7638,7 @@ if test $libc_cv_cc_loop_to_function = yes; then
 fi
 
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -Wimplicit-fallthrough" >&5
 printf %s "checking for -Wimplicit-fallthrough... " >&6; }
 if test ${libc_cv_cc_wimplicit_fallthrough+y}
@@ -7480,17 +7654,50 @@ else case e in #(
 then :
   libc_cv_cc_wimplicit_fallthrough=-Wimplicit-fallthrough
 else case e in #(
-  e) libc_cv_cc_wimplicit_fallthrough= ;;
+  e) libc_cv_cc_wimplicit_fallthrough=-Wimplicit-fallthrough ;;
 esac
-fi
- ;;
+fi ;;
 esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_wimplicit_fallthrough" >&5
 printf "%s\n" "$libc_cv_cc_wimplicit_fallthrough" >&6; }
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_cc_wimplicit_fallthrough=$libc_cv_cc_wimplicit_fallthrough
+else
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for -Wimplicit-fallthrough in testing" >&5
+printf %s "checking for -Wimplicit-fallthrough in testing... " >&6; }
+if test ${libc_cv_test_cc_wimplicit_fallthrough+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) if { ac_try='${CC-cc} -Werror -Wimplicit-fallthrough -xc /dev/null -S -o /dev/null'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+then :
+  libc_cv_test_cc_wimplicit_fallthrough=-Wimplicit-fallthrough
+else case e in #(
+  e) libc_cv_test_cc_wimplicit_fallthrough= ;;
+esac
+fi ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_cc_wimplicit_fallthrough" >&5
+printf "%s\n" "$libc_cv_test_cc_wimplicit_fallthrough" >&6; }
+
+CC="$saved_CC"
+
+fi
+
 config_vars="$config_vars
 cc-option-wimplicit-fallthrough = $libc_cv_cc_wimplicit_fallthrough"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for libgd" >&5
 printf %s "checking for libgd... " >&6; }
 if test "$with_gd" != "no"; then
@@ -7721,6 +7928,7 @@ fi
 no_fortify_source="-U_FORTIFY_SOURCE"
 fortify_source="${no_fortify_source}"
 
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for maximum supported _FORTIFY_SOURCE level" >&5
 printf %s "checking for maximum supported _FORTIFY_SOURCE level... " >&6; }
 if test ${libc_cv_supported_fortify_source+y}
@@ -7728,7 +7936,7 @@ then :
   printf %s "(cached) " >&6
 else case e in #(
   e)
-    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
 int
@@ -7753,6 +7961,50 @@ esac
 fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_supported_fortify_source" >&5
 printf "%s\n" "$libc_cv_supported_fortify_source" >&6; }
+if test "$TEST_CC" = "$CC"; then
+  libc_cv_test_supported_fortify_source=$libc_cv_supported_fortify_source
+else
+
+saved_CC="$CC"
+CC="$TEST_CC"
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for maximum supported _FORTIFY_SOURCE level in testing" >&5
+printf %s "checking for maximum supported _FORTIFY_SOURCE level in testing... " >&6; }
+if test ${libc_cv_test_supported_fortify_source+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e)
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+__builtin_dynamic_object_size("", 0)
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"
+then :
+  libc_cv_test_supported_fortify_source=3
+else case e in #(
+  e) libc_cv_test_supported_fortify_source=2 ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+     ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_test_supported_fortify_source" >&5
+printf "%s\n" "$libc_cv_test_supported_fortify_source" >&6; }
+
+CC="$saved_CC"
+
+fi
+
+
 
 case $enable_fortify_source in #(
   yes) :
@@ -8244,6 +8496,11 @@ fi
 config_vars="$config_vars
 enable-static-pie = $libc_cv_static_pie"
 
+# Support configure.ac under sysdeps.
+
+
+
+
 # Set the `multidir' variable by grabbing the variable from the compiler.
 # We do it once and save the result in a generated makefile.
 libc_cv_multidir=`${CC-cc} $CFLAGS $CPPFLAGS -print-multi-directory`