Refine .cfi_sections check to only consider compact eh_frame

The .cfi_sections directive can be safely used multiple times
with different sections named at any time unless the compact form
of exception handling is requested after CFI information has
been emitted.  Only the compact form of CFI information changes
the way in which CFI is generated and therefore cannot be
retrospectively requested after generating CFI information.

gas/

	PR gas/20648
	* dw2gencfi.c (dot_cfi_sections): Refine the check for
	inconsistent .cfi_sections to only consider compact vs non
	compact forms.
	* testsuite/gas/cfi/cfi-common-9.d: New file.
	* testsuite/gas/cfi/cfi-common-9.s: New file.
	* testsuite/gas/cfi/cfi.exp: Run new test.

Author: mfortune

gas/ChangeLog

@@ -1,3 +1,13 @@
+2016-10-06  Matthew Fortune  <[email protected]>
+
+	PR gas/20648
+	* dw2gencfi.c (dot_cfi_sections): Refine the check for
+	inconsistent .cfi_sections to only consider compact vs non
+	compact forms.
+	* testsuite/gas/cfi/cfi-common-9.d: New file.
+	* testsuite/gas/cfi/cfi-common-9.s: New file.
+	* testsuite/gas/cfi/cfi.exp: Run new test.
+
 2016-10-06  Alan Modra  <[email protected]>
 
 	* app.c: Add missing fall through comments.

gas/dw2gencfi.c

@@ -1269,7 +1269,10 @@ dot_cfi_sections (int ignored ATTRIBUTE_UNUSED)
       }
 
   demand_empty_rest_of_line ();
-  if (cfi_sections_set && cfi_sections != sections)
+  if (cfi_sections_set
+      && (sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact))
+      && (cfi_sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact))
+	 != (sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact)))
     as_bad (_("inconsistent uses of .cfi_sections"));
   cfi_sections = sections;
 }

gas/testsuite/gas/cfi/cfi-common-9.d

@@ -0,0 +1,23 @@
+#objdump: -Wf
+#name: CFI common 9
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: .*
+  Data alignment factor: .*
+  Return address column: .*
+  Augmentation data:     [01]b
+
+  DW_CFA_nop
+  DW_CFA_nop
+  DW_CFA_nop
+
+00000014 0+00(10|18|1c|20) 0+0018 FDE cie=0+0000 pc=.*
+
+  DW_CFA_nop
+  DW_CFA_nop
+  DW_CFA_nop
+#...

gas/testsuite/gas/cfi/cfi-common-9.s

@@ -0,0 +1,4 @@
+	.cfi_sections .eh_frame
+	.cfi_startproc simple
+	.cfi_sections .debug_frame
+	.cfi_endproc

gas/testsuite/gas/cfi/cfi.exp

@@ -136,4 +136,5 @@ if { ![istarget "hppa64*-*"] } then {
   }
   run_dump_test "cfi-common-7"
   run_dump_test "cfi-common-8"
+  run_dump_test "cfi-common-9"
 }