Re: [PATCH] Fix possible alignment issue with dw2-dir-file-name test case

[Pedro Alves <palves at redhat dot com>]

On 01/10/2014 02:53 PM, Jan Kratochvil wrote:
> On Fri, 10 Jan 2014 15:30:46 +0100, Andreas Arnez wrote:
>> It's certainly simpler.  Maybe Jan can explain why the functions had
>> been declared static?
>>
>> Your patch fixes the FAILs for me, so if there's no reason for the
>> static-ness, then I agree we should go with that.
> 
> The Pedro's patch should be OK, there is nothing magic there.
> 

Thanks.

On 01/10/2014 03:32 PM, Pedro Alves wrote:
> On 01/10/2014 02:30 PM, Andreas Arnez wrote:
>>
>> Your patch fixes the FAILs for me, so if there's no reason for the
>> static-ness, then I agree we should go with that.
>
> OK, I'll merge it with Andreas' commit log, and push it in in a sec.

(Eh, I had meant to send that as reply to Jan, but somehow managed
to botch it.)

Here's what I pushed.

--------
From: Andreas Arnez <arnez@linux.vnet.ibm.com>
Date: Fri, 10 Jan 2014 15:37:36 +0000
Subject: [PATCH] Since upstream gcc has recently increased the function
 alignment on S390, the dw2-dir-file-name test case fails in
 the first gdb_continue_to_breakpoint.  Indeed, the
 breakpoint is now placed into the alignment gap *before*
 the actual function.

This happens because the test case declares the respective "*_start"
symbol as a "loose" label before the function definition, and the
compiler inserts the alignment between that label and the function
itself.

The "*_start" symbols were only necessary because FUNC made the
function static.  The fix makes the functions extern instead, thus
making the "*_start" labels unnecessary.

testsuite/
2014-01-10  Andreas Arnez  <arnez@linux.vnet.ibm.com>
	    Pedro Alves <palves@redhat.com>

	* gdb.dwarf2/dw2-dir-file-name.c (FUNC): Remove "*_start" symbol.
	Make "name" extern.
	* gdb.dwarf2/dw2-dir-file-name.exp (out_cu, out_line): Replace
	references to ${name}_start by references to ${name}.
---
 gdb/testsuite/ChangeLog                        | 8 ++++++++
 gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c   | 3 +--
 gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp | 6 +++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 2bfeec1..904cca7 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2014-01-10  Andreas Arnez  <arnez@linux.vnet.ibm.com>
+	    Pedro Alves <palves@redhat.com>
+
+	* gdb.dwarf2/dw2-dir-file-name.c (FUNC): Remove "*_start" symbol.
+	Make "name" extern.
+	* gdb.dwarf2/dw2-dir-file-name.exp (out_cu, out_line): Replace
+	references to ${name}_start by references to ${name}.
+
 2014-01-10  Joel Brobecker  <brobecker@adacore.com>

 	* gdb.ada/pp-rec-component.exp: Remove path from "source" test.
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
index 21a4d2a..2b9cc6a 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
+++ b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c
@@ -64,8 +64,7 @@ FUNC (compdir_absolute_ldir_absolute_file_absolute_same)	\
 FUNC (compdir_absolute_ldir_absolute_file_absolute_different)

 #define FUNC(name)					\
-  asm (#name "_start: .globl " #name "_start\n");	\
-  static void						\
+  void							\
   name (void)						\
   {							\
     v++;						\
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
index 7f29581..e523e89 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
+++ b/gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp
@@ -54,7 +54,7 @@ proc out_cu { name cu_dir cu_name line_dir line_name } {
 	.ascii	\"GNU C\\0\"			/* DW_AT_producer */
 	.byte	2				/* DW_AT_language (DW_LANG_C) */
 	.4byte	.Lline_${name}_begin		/* DW_AT_stmt_list */
-	.4byte	${name}_start			/* DW_AT_low_pc */
+	.4byte	${name}			/* DW_AT_low_pc */
 	.4byte	${name}_end			/* DW_AT_high_pc */
 "
     if { $cu_dir != "" } {
@@ -65,7 +65,7 @@ proc out_cu { name cu_dir cu_name line_dir line_name } {

 	.uleb128	3			/* Abbrev: DW_TAG_subprogram */
 	.asciz		\"${name}\"		/* DW_AT_name */
-	.4byte		${name}_start		/* DW_AT_low_pc */
+	.4byte		${name}		/* DW_AT_low_pc */
 	.4byte		${name}_end		/* DW_AT_high_pc */

 	.byte		0			/* End of children of CU */
@@ -122,7 +122,7 @@ proc out_line { name cu_dir cu_name line_dir line_name } {
 	.byte		0	/* DW_LNE_set_address */
 	.uleb128	5
 	.byte		2
-	.4byte		${name}_start
+	.4byte		${name}
 	.byte		1	/* DW_LNS_copy */
 	.byte		3	/* DW_LNS_advance_line */
 	.sleb128	1	/* ... to 1000 */
-- 
1.7.11.7