[glibc] scripts: Fix fortify checks if compiler does not support _FORTIFY_SOURCE=3

[glibc] scripts: Fix fortify checks if compiler does not support _FORTIFY_SOURCE=3

[Adhemerval Zanella]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a3090c2c98facbab3d47aa23a94f8d2caeb78d71

commit a3090c2c98facbab3d47aa23a94f8d2caeb78d71
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Thu Jul 20 11:35:54 2023 -0300

    scripts: Fix fortify checks if compiler does not support _FORTIFY_SOURCE=3
    
    The 30379efad1 added _FORTIFY_SOURCE checks without check if compiler
    does support all used fortify levels.  This patch fixes it by first
    checking at configure time the maximum support fortify level and using
    it instead of a pre-defined one.
    
    Checked on x86_64 with gcc 11, 12, and 13.
    
    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    Tested-by: Florian Weimer <fweimer@redhat.com>

Diff:
---
 Makefile                           |  4 ++--
 Rules                              |  4 ++--
 configure                          | 28 ++++++++++++----------------
 configure.ac                       | 13 +++++++------
 scripts/check-installed-headers.sh | 11 +++++++----
 5 files changed, 30 insertions(+), 30 deletions(-)

diff --git a/Makefile b/Makefile
index f324df7a1f..c6d4817a9e 100644
--- a/Makefile
+++ b/Makefile
@@ -545,7 +545,7 @@ tests-special += $(objpfx)check-installed-headers-c.out
 libof-check-installed-headers-c := testsuite
 $(objpfx)check-installed-headers-c.out: \
     scripts/check-installed-headers.sh $(headers)
-	$(SHELL) $(..)scripts/check-installed-headers.sh c \
+	$(SHELL) $(..)scripts/check-installed-headers.sh c $(supported-fortify) \
 	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
 	  $(headers) > $@; \
 	$(evaluate-test)
@@ -555,7 +555,7 @@ tests-special += $(objpfx)check-installed-headers-cxx.out
 libof-check-installed-headers-cxx := testsuite
 $(objpfx)check-installed-headers-cxx.out: \
     scripts/check-installed-headers.sh $(headers)
-	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
+	$(SHELL) $(..)scripts/check-installed-headers.sh c++ $(supported-fortify) \
 	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
 	  $(headers) > $@; \
 	$(evaluate-test)
diff --git a/Rules b/Rules
index 5e945d7347..279ae490ac 100644
--- a/Rules
+++ b/Rules
@@ -85,7 +85,7 @@ tests-special += $(objpfx)check-installed-headers-c.out
 libof-check-installed-headers-c := testsuite
 $(objpfx)check-installed-headers-c.out: \
     $(..)scripts/check-installed-headers.sh $(headers)
-	$(SHELL) $(..)scripts/check-installed-headers.sh c \
+	$(SHELL) $(..)scripts/check-installed-headers.sh c $(supported-fortify) \
 	  "$(CC) $(filter-out -std=%,$(CFLAGS)) -D_ISOMAC $(+includes)" \
 	  $(headers) > $@; \
 	$(evaluate-test)
@@ -97,7 +97,7 @@ tests-special += $(objpfx)check-installed-headers-cxx.out
 libof-check-installed-headers-cxx := testsuite
 $(objpfx)check-installed-headers-cxx.out: \
     $(..)scripts/check-installed-headers.sh $(headers)
-	$(SHELL) $(..)scripts/check-installed-headers.sh c++ \
+	$(SHELL) $(..)scripts/check-installed-headers.sh c++ $(supported-fortify) \
 	  "$(CXX) $(filter-out -std=%,$(CXXFLAGS)) -D_ISOMAC $(+includes)" \
 	  $(headers) > $@; \
 	$(evaluate-test)
diff --git a/configure b/configure
index d2a0eb9734..4ef387146d 100755
--- a/configure
+++ b/configure
@@ -7610,9 +7610,9 @@ fi
 no_fortify_source="-Wp,-U_FORTIFY_SOURCE"
 fortify_source="${no_fortify_source}"
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for __builtin_dynamic_object_size" >&5
-printf %s "checking for __builtin_dynamic_object_size... " >&6; }
-if test ${libc_cv___builtin_dynamic_object_size+y}
+{ printf "%s\n" "$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}
 then :
   printf %s "(cached) " >&6
 else $as_nop
@@ -7630,30 +7630,24 @@ __builtin_dynamic_object_size("", 0)
 _ACEOF
 if ac_fn_c_try_link "$LINENO"
 then :
-  libc_cv___builtin_dynamic_object_size=yes
-         if test "$enable_fortify_source" = yes
-then :
-  enable_fortify_source=3
-fi
+  libc_cv_supported_fortify_source=3
 else $as_nop
-  libc_cv___builtin_dynamic_object_size=no
-         if test "$enable_fortify_source" = yes
-then :
-  enable_fortify_source=2
-fi
+  libc_cv_supported_fortify_source=2
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.beam \
     conftest$ac_exeext conftest.$ac_ext
 
 fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv___builtin_dynamic_object_size" >&5
-printf "%s\n" "$libc_cv___builtin_dynamic_object_size" >&6; }
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_cv_supported_fortify_source" >&5
+printf "%s\n" "$libc_cv_supported_fortify_source" >&6; }
 
 case $enable_fortify_source in #(
+  yes) :
+    libc_cv_fortify_source=yes enable_fortify_source=$libc_cv_supported_fortify_source ;; #(
   1|2) :
     libc_cv_fortify_source=yes ;; #(
   3) :
-    if test "$libc_cv___builtin_dynamic_object_size" = yes
+    if test $libc_cv_supported_fortify_source = 3
 then :
   libc_cv_fortify_source=yes
 else $as_nop
@@ -7673,6 +7667,8 @@ fi
 
 
 
+config_vars="$config_vars
+supported-fortify = $libc_cv_supported_fortify_source"
 
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether the assembler requires one version per symbol" >&5
 printf %s "checking whether the assembler requires one version per symbol... " >&6; }
diff --git a/configure.ac b/configure.ac
index f508a3722b..12d1f50b14 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1578,17 +1578,17 @@ dnl support it
 no_fortify_source="-Wp,-U_FORTIFY_SOURCE"
 fortify_source="${no_fortify_source}"
 
-AC_CACHE_CHECK([for __builtin_dynamic_object_size], [libc_cv___builtin_dynamic_object_size], [
+AC_CACHE_CHECK([for maximum supported _FORTIFY_SOURCE level],
+	       [libc_cv_supported_fortify_source], [
     AC_LINK_IFELSE([AC_LANG_PROGRAM([], [__builtin_dynamic_object_size("", 0)])],
-        [libc_cv___builtin_dynamic_object_size=yes
-         AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=3])],
-        [libc_cv___builtin_dynamic_object_size=no
-         AS_IF([test "$enable_fortify_source" = yes], [enable_fortify_source=2])])
+        [libc_cv_supported_fortify_source=3],
+        [libc_cv_supported_fortify_source=2])
 ])
 
 AS_CASE([$enable_fortify_source],
+        [yes], [libc_cv_fortify_source=yes enable_fortify_source=$libc_cv_supported_fortify_source],
         [1|2], [libc_cv_fortify_source=yes],
-        [3], [AS_IF([test "$libc_cv___builtin_dynamic_object_size" = yes],
+        [3], [AS_IF([test $libc_cv_supported_fortify_source = 3],
                     [libc_cv_fortify_source=yes],
                     [AC_MSG_ERROR([Compiler doesn't provide necessary support for _FORTIFY_SOURCE=3])])],
         [libc_cv_fortify_source=no])
@@ -1601,6 +1601,7 @@ AC_SUBST(enable_fortify_source)
 AC_SUBST(libc_cv_fortify_source)
 AC_SUBST(no_fortify_source)
 AC_SUBST(fortify_source)
+LIBC_CONFIG_VAR([supported-fortify], [$libc_cv_supported_fortify_source])
 
 dnl Starting with binutils 2.35, GAS can attach multiple symbol versions
 dnl to one symbol (PR 23840).
diff --git a/scripts/check-installed-headers.sh b/scripts/check-installed-headers.sh
index 23506a2514..ee9f534ab0 100644
--- a/scripts/check-installed-headers.sh
+++ b/scripts/check-installed-headers.sh
@@ -29,11 +29,12 @@ cxx_modes="-std=c++98 -std=gnu++98 -std=c++11 -std=gnu++11"
 # These are probably the most commonly used three.
 lib_modes="-D_DEFAULT_SOURCE=1 -D_GNU_SOURCE=1 -D_XOPEN_SOURCE=700"
 
-# Also check for fortify modes, since it might be enabled as default.
-fortify_modes="1 2 3"
+# Also check for fortify modes, since it might be enabled as default.  The
+# maximum value to be checked is define by maximum_fortify argument.
+fortify_modes=""
 
 if [ $# -lt 3 ]; then
-    echo "usage: $0 c|c++ \"compile command\" header header header..." >&2
+    echo "usage: $0 c|c++ maximum_fortify \"compile command\" header header header..." >&2
     exit 2
 fi
 case "$1" in
@@ -50,6 +51,8 @@ case "$1" in
         exit 2;;
 esac
 shift
+fortify_modes=$(seq -s' ' 1 $1)
+shift
 cc_cmd="$1"
 shift
 trap "rm -f '$cih_test_c'" 0
@@ -104,7 +107,6 @@ EOF
     for lang_mode in "" $lang_modes; do
         for lib_mode in "" $lib_modes; do
             for fortify_mode in "" $fortify_modes; do
-                echo :::: $lang_mode $lib_mode $fortify_mode
                 if [ -z "$lib_mode" ]; then
                     expanded_lib_mode='/* default library mode */'
                 else
@@ -114,6 +116,7 @@ EOF
                 if [ ! -z $fortify_mode ]; then
                     fortify_mode="#define _FORTIFY_SOURCE $fortify_mode"
                 fi
+                echo :::: $lang_mode $lib_mode $fortify_mode
                 cat >"$cih_test_c" <<EOF
 /* These macros may have been defined on the command line.  They are
    inappropriate for this test.  */