[PATCH, committed] Set SECTION_EXCLUDE flag for LTO sections.

[Ilya Verbin <iverbin at gmail dot com>]

Hello,

This patch sets SECTION_EXCLUDE flag for LTO sections in lhd_begin_section and
fixes the corresponding gcc_GAS_CHECK_FEATURE.

Approved here: https://gcc.gnu.org/ml/gcc-patches/2014-10/msg01535.html
Bootstrapped and regtested on i686-linux and x86_64-linux, committed to trunk.

  -- Ilya


2014-10-19  Ilya Verbin  <ilya.verbin@intel.com>

gcc/
	* configure: Regenerate.
	* configure.ac: Move the test for section attribute specifier "e" in GAS
	out to all i[34567]86-*-* | x86_64-*-* targets and add --fatal-warnings.
	* langhooks.c (lhd_begin_section): Set SECTION_EXCLUDE flag.
	* varasm.c (default_elf_asm_named_section): Guard SECTION_EXCLUDE with
	ifdef HAVE_GAS_SECTION_EXCLUDE.

---

diff --git a/gcc/configure b/gcc/configure
index bd1215d..16f128f 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -24676,9 +24676,12 @@ $as_echo "$as_me: WARNING: LTO for $target requires binutils >= 2.20.1, but vers
 	      ;;
 	  esac
 	fi
-	# Test if the assembler supports the section flag 'e' for specifying
-	# an excluded section.
-	{ $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for .section with e" >&5
+	;;
+    esac
+
+    # Test if the assembler supports the section flag 'e' for specifying
+    # an excluded section.
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for .section with e" >&5
 $as_echo_n "checking assembler for .section with e... " >&6; }
 if test "${gcc_cv_as_section_has_e+set}" = set; then :
   $as_echo_n "(cached) " >&6
@@ -24691,7 +24694,7 @@ fi
   elif test x$gcc_cv_as != x; then
     $as_echo '.section foo1,"e"
 .byte 0,0,0,0' > conftest.s
-    if { ac_try='$gcc_cv_as $gcc_cv_as_flags  -o conftest.o conftest.s >&5'
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags --fatal-warnings -o conftest.o conftest.s >&5'
   { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
   (eval $ac_try) 2>&5
   ac_status=$?
@@ -24714,8 +24717,6 @@ cat >>confdefs.h <<_ACEOF
 #define HAVE_GAS_SECTION_EXCLUDE `if test $gcc_cv_as_section_has_e = yes; then echo 1; else echo 0; fi`
 _ACEOF
 
-	;;
-    esac
 
     { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for filds and fists mnemonics" >&5
 $as_echo_n "checking assembler for filds and fists mnemonics... " >&6; }
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 8f7c814..35ce9ee 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -3799,18 +3799,19 @@ foo:	nop
 	      ;;
 	  esac
 	fi
-	# Test if the assembler supports the section flag 'e' for specifying
-	# an excluded section.
-	gcc_GAS_CHECK_FEATURE([.section with e], gcc_cv_as_section_has_e,
-	  [2,22,51],,
-[.section foo1,"e"
-.byte 0,0,0,0])
-	AC_DEFINE_UNQUOTED(HAVE_GAS_SECTION_EXCLUDE,
-	  [`if test $gcc_cv_as_section_has_e = yes; then echo 1; else echo 0; fi`],
-          [Define if your assembler supports specifying the section flag e.])
 	;;
     esac
 
+    # Test if the assembler supports the section flag 'e' for specifying
+    # an excluded section.
+    gcc_GAS_CHECK_FEATURE([.section with e], gcc_cv_as_section_has_e,
+      [2,22,51], [--fatal-warnings],
+[.section foo1,"e"
+.byte 0,0,0,0])
+    AC_DEFINE_UNQUOTED(HAVE_GAS_SECTION_EXCLUDE,
+      [`if test $gcc_cv_as_section_has_e = yes; then echo 1; else echo 0; fi`],
+      [Define if your assembler supports specifying the section flag e.])
+
     gcc_GAS_CHECK_FEATURE([filds and fists mnemonics],
        gcc_cv_as_ix86_filds,,,
        [filds mem; fists mem],,
diff --git a/gcc/langhooks.c b/gcc/langhooks.c
index 7d4c294..4bdeaa0 100644
--- a/gcc/langhooks.c
+++ b/gcc/langhooks.c
@@ -660,7 +660,7 @@ lhd_begin_section (const char *name)
     saved_section = text_section;
 
   /* Create a new section and switch to it.  */
-  section = get_section (name, SECTION_DEBUG, NULL);
+  section = get_section (name, SECTION_DEBUG | SECTION_EXCLUDE, NULL);
   switch_to_section (section);
 }
 
diff --git a/gcc/varasm.c b/gcc/varasm.c
index abb743b..4ae9d58 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -6141,8 +6141,10 @@ default_elf_asm_named_section (const char *name, unsigned int flags,
 
   if (!(flags & SECTION_DEBUG))
     *f++ = 'a';
+#if defined (HAVE_GAS_SECTION_EXCLUDE) && HAVE_GAS_SECTION_EXCLUDE == 1
   if (flags & SECTION_EXCLUDE)
     *f++ = 'e';
+#endif
   if (flags & SECTION_WRITE)
     *f++ = 'w';
   if (flags & SECTION_CODE)
-- 
1.7.1