Allow the .cfi_sections directive to be reissued provided that CFI generation has not yet started.

	PR gas/19614
	* dw2gencfi.c (cfi_sections_set): Delay setting this variable
	until it is actually used.
	(cfi_set_sections): Set cfi_sections_set to true.
	(dot_cfi_startproc): Likewise.
	(dot_cfi_endproc): Likewise.
	(dot_cfi_fde_data): Likewise.
	(cfi_finish): Likewise.
	(dot_cfi_sections): Do not set cfi_sections_set.
	* doc/as.texinfo (.cfi_sections): Note that targets can provide
	their own cfi section name.  Also note that the directive can be
	reissued provided that CFI generation has not started.
	* testsuite/gas/mips/compact-eh-err2.s: Add .cfi_startproc and
	.cfi_endproc directives so that the redefinition of .cfi_sections
	will trigger the generation of the error message.
	* testsuite/gas/mips/compact-eh-err2.l: Update expected line
	number of error message.

5 files changed, 38 insertions, 2 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 1d6a178..c72e504 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,23 @@
+2016-02-11  Nick Clifton  <nickc@redhat.com>
+
+	PR gas/19614
+	* dw2gencfi.c (cfi_sections_set): Delay setting this variable
+	until it is actually used.
+	(cfi_set_sections): Set cfi_sections_set to true.
+	(dot_cfi_startproc): Likewise.
+	(dot_cfi_endproc): Likewise.
+	(dot_cfi_fde_data): Likewise.
+	(cfi_finish): Likewise.
+	(dot_cfi_sections): Do not set cfi_sections_set.
+	* doc/as.texinfo (.cfi_sections): Note that targets can provide
+	their own cfi section name.  Also note that the directive can be
+	reissued provided that CFI generation has not started.
+	* testsuite/gas/mips/compact-eh-err2.s: Add .cfi_startproc and
+	.cfi_endproc directives so that the redefinition of .cfi_sections
+	will trigger the generation of the error message.
+	* testsuite/gas/mips/compact-eh-err2.l: Update expected line
+	number of error message.
+
 2016-02-10  Claudiu Zissulescu  <claziss@synopsys.com>
 	    Janek van Oirschot <jvanoirs@synopsys.com>
 
diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo
index 90611a3..917781b 100644
--- a/gas/doc/as.texinfo
+++ b/gas/doc/as.texinfo
@@ -4683,6 +4683,14 @@ directive is not used is @code{.cfi_sections .eh_frame}.
 On targets that support compact unwinding tables these can be generated
 by specifying @code{.eh_frame_entry} instead of @code{.eh_frame}.
 
+Some targets may support an additional name, such as @code{.c6xabi.exidx}
+which is used by the @value{TIC6X} target.
+
+The @code{.cfi_sections} directive can be repeated, with the same or different
+arguments, provided that CFI generation has not yet started.  Once CFI
+generation has started however the section list is fixed and any attempts to
+redefine it will result in an error.
+
 @subsection @code{.cfi_startproc [simple]}
 @cindex @code{cfi_startproc} directive
 @code{.cfi_startproc} is used at the beginning of each function that
diff --git a/gas/dw2gencfi.c b/gas/dw2gencfi.c
index 195013b..c66402d 100644
--- a/gas/dw2gencfi.c
+++ b/gas/dw2gencfi.c
@@ -509,6 +509,7 @@ void
 cfi_set_sections (void)
 {
   frchain_now->frch_cfi_data->cur_fde_data->sections = all_cfi_sections;
+  cfi_sections_set = TRUE;
 }
 
 /* Universal functions to store new instructions.  */
@@ -1248,7 +1249,6 @@ dot_cfi_sections (int ignored ATTRIBUTE_UNUSED)
   demand_empty_rest_of_line ();
   if (cfi_sections_set && cfi_sections != sections)
     as_bad (_("inconsistent uses of .cfi_sections"));
-  cfi_sections_set = TRUE;
   cfi_sections = sections;
 }
 
@@ -1284,6 +1284,7 @@ dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED)
     }
   demand_empty_rest_of_line ();
 
+  cfi_sections_set = TRUE;
   all_cfi_sections |= cfi_sections;
   cfi_set_sections ();
   frchain_now->frch_cfi_data->cur_cfa_offset = 0;
@@ -1310,6 +1311,7 @@ dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED)
 
   demand_empty_rest_of_line ();
 
+  cfi_sections_set = TRUE;
   if ((cfi_sections & CFI_EMIT_target) != 0)
     tc_cfi_endproc (last_fde);
 }
@@ -1372,6 +1374,7 @@ dot_cfi_fde_data (int ignored ATTRIBUTE_UNUSED)
 
   last_fde = frchain_now->frch_cfi_data->cur_fde_data;
 
+  cfi_sections_set = TRUE;
   if ((cfi_sections & CFI_EMIT_target) != 0
       || (cfi_sections & CFI_EMIT_eh_frame_compact) != 0)
     {
@@ -2223,6 +2226,7 @@ cfi_finish (void)
   if (all_fde_data == 0)
     return;
 
+  cfi_sections_set = TRUE;
   if ((all_cfi_sections & CFI_EMIT_eh_frame) != 0
       || (all_cfi_sections & CFI_EMIT_eh_frame_compact) != 0)
     {
@@ -2408,6 +2412,7 @@ cfi_finish (void)
       flag_traditional_format = save_flag_traditional_format;
     }
 
+  cfi_sections_set = TRUE;
   if ((all_cfi_sections & CFI_EMIT_debug_frame) != 0)
     {
       int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1;
diff --git a/gas/testsuite/gas/mips/compact-eh-err2.l b/gas/testsuite/gas/mips/compact-eh-err2.l
index c52976a..11e9b8e 100644
--- a/gas/testsuite/gas/mips/compact-eh-err2.l
+++ b/gas/testsuite/gas/mips/compact-eh-err2.l
@@ -1,2 +1,2 @@
 .*: Assembler messages:
-.*:7: Error: inconsistent uses of .cfi_sections
+.*:8: Error: inconsistent uses of .cfi_sections
diff --git a/gas/testsuite/gas/mips/compact-eh-err2.s b/gas/testsuite/gas/mips/compact-eh-err2.s
index acf83d1..2ce265a 100644
--- a/gas/testsuite/gas/mips/compact-eh-err2.s
+++ b/gas/testsuite/gas/mips/compact-eh-err2.s
@@ -4,4 +4,7 @@
 	.align	2
 	.globl	_Z3fooi
 	.cfi_sections .eh_frame_entry
+	.cfi_startproc
 	.cfi_sections .eh_frame
+	.cfi_endproc
+