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

[Pedro Alves <palves@redhat.com>]

On 01/08/2014 06:00 PM, Andreas Arnez wrote:
> 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 fix defines the "*_start" symbol as a global alias to the
> function instead.

It seems the _start symbol only needs to exist because
the functions were declared static:

> -#define FUNC(name)					\
> -  asm (#name "_start: .globl " #name "_start\n");	\
> -  static void						\
> -  name (void)						\

But I see nothing that needs them to be static.  This
seems simpler to me:

---
 gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.c   | 3 +--
 gdb/testsuite/gdb.dwarf2/dw2-dir-file-name.exp | 6 +++---
 2 files changed, 4 insertions(+), 5 deletions(-)

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