re PR debug/40521 (-g causes GCC to generate .eh_frame)

	PR debug/40521
	* configure.ac (HAVE_GAS_CFI_SECTIONS_DIRECTIVE): New test.
	* configure: Regenerated.
	* config.in: Regenerated.
	* dwarf2out.c (dwarf2out_do_cfi_asm): Return false if
	!HAVE_GAS_CFI_SECTIONS_DIRECTIVE and not emitting .eh_frame.
	(dwarf2out_init): If HAVE_GAS_CFI_SECTIONS_DIRECTIVE and
	not emitting .eh_frame, emit .cfi_sections .debug_frame
	directive.

From-SVN: r152414

gcc/ChangeLog

 2009-10-02  Jakub Jelinek  <jakub@redhat.com>
 
+	PR debug/40521
+	* configure.ac (HAVE_GAS_CFI_SECTIONS_DIRECTIVE): New test.
+	* configure: Regenerated.
+	* config.in: Regenerated.
+	* dwarf2out.c (dwarf2out_do_cfi_asm): Return false if
+	!HAVE_GAS_CFI_SECTIONS_DIRECTIVE and not emitting .eh_frame.
+	(dwarf2out_init): If HAVE_GAS_CFI_SECTIONS_DIRECTIVE and
+	not emitting .eh_frame, emit .cfi_sections .debug_frame
+	directive.
+
 	PR debug/41404
 	PR debug/41353
 	* cfgexpand.c (expand_debug_expr) <case STRING_CST>: Don't create

gcc/config.in

@@ -887,6 +887,12 @@
 #endif
 
 
+/* Define 0/1 if your assembler supports .cfi_sections. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GAS_CFI_SECTIONS_DIRECTIVE
+#endif
+
+
 /* Define if your assembler supports the .loc discriminator sub-directive. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_GAS_DISCRIMINATOR

gcc/configure

@@ -21542,6 +21542,42 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for cfi sections directive" >&5
+$as_echo_n "checking assembler for cfi sections directive... " >&6; }
+if test "${gcc_cv_as_cfi_sections_directive+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_cfi_sections_directive=no
+  if test x$gcc_cv_as != x; then
+    echo '	.text
+	.cfi_sections .debug_frame, .eh_frame
+	.cfi_startproc
+	.cfi_endproc' > conftest.s
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_cfi_sections_directive=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_cfi_sections_directive" >&5
+$as_echo "$gcc_cv_as_cfi_sections_directive" >&6; }
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_GAS_CFI_SECTIONS_DIRECTIVE `if test $gcc_cv_as_cfi_sections_directive = yes;
+    then echo 1; else echo 0; fi`
+_ACEOF
+
+
 # GAS versions up to and including 2.11.0 may mis-optimize
 # .eh_frame data.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for eh_frame optimization" >&5

gcc/configure.ac

@@ -2301,6 +2301,17 @@ AC_DEFINE_UNQUOTED(HAVE_GAS_CFI_PERSONALITY_DIRECTIVE,
     then echo 1; else echo 0; fi`],
   [Define 0/1 if your assembler supports .cfi_personality.])
 
+gcc_GAS_CHECK_FEATURE([cfi sections directive],
+  gcc_cv_as_cfi_sections_directive, ,,
+[	.text
+	.cfi_sections .debug_frame, .eh_frame
+	.cfi_startproc
+	.cfi_endproc])
+AC_DEFINE_UNQUOTED(HAVE_GAS_CFI_SECTIONS_DIRECTIVE,
+  [`if test $gcc_cv_as_cfi_sections_directive = yes;
+    then echo 1; else echo 0; fi`],
+  [Define 0/1 if your assembler supports .cfi_sections.])
+
 # GAS versions up to and including 2.11.0 may mis-optimize
 # .eh_frame data.
 gcc_GAS_CHECK_FEATURE(eh_frame optimization, gcc_cv_as_eh_frame,

gcc/dwarf2out.c

@@ -179,6 +179,16 @@ dwarf2out_do_cfi_asm (void)
   if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
     return false;
 
+  if (!HAVE_GAS_CFI_SECTIONS_DIRECTIVE)
+    {
+#ifdef TARGET_UNWIND_INFO
+      return false;
+#else
+      if (USING_SJLJ_EXCEPTIONS || (!flag_unwind_tables && !flag_exceptions))
+	return false;
+#endif
+    }
+
   saved_do_cfi_asm = true;
   return true;
 }
@@ -18628,6 +18638,16 @@ dwarf2out_init (const char *filename ATTRIBUTE_UNUSED)
       switch_to_section (cold_text_section);
       ASM_OUTPUT_LABEL (asm_out_file, cold_text_section_label);
     }
+
+#ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE
+  if (dwarf2out_do_cfi_asm ())
+    {
+#ifndef TARGET_UNWIND_INFO
+      if (USING_SJLJ_EXCEPTIONS || (!flag_unwind_tables && !flag_exceptions))
+#endif
+	fprintf (asm_out_file, "\t.cfi_sections\t.debug_frame\n");
+    }
+#endif
 }
 
 /* A helper function for dwarf2out_finish called through