[binutils-gdb] Fix gdb.reverse/finish-reverse-bkpt.exp

[Yao Qi <qiyao at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c8064e7e9b4d7d9cc29a613af899a7739df60be6

commit c8064e7e9b4d7d9cc29a613af899a7739df60be6
Author: Yao Qi <yao.qi@linaro.org>
Date:   Thu Apr 7 17:06:14 2016 +0100

    Fix gdb.reverse/finish-reverse-bkpt.exp
    
    I see the following fail on aarch64-linux
    
     break void_func
     Breakpoint 2 at 0x4007a0: file gdb/testsuite/gdb.reverse/finish-reverse.c, line 44.
     (gdb) PASS: gdb.reverse/finish-reverse-bkpt.exp: set breakpoint on void_func
     continue
     Continuing.
    
     Breakpoint 2, void_func () at gdb/testsuite/gdb.reverse/finish-reverse.c:44^M
     44        void_test = 1;                /* VOID FUNC */^M
     (gdb) PASS: gdb.reverse/finish-reverse-bkpt.exp: continue to breakpoint: void_func
     break *void_func^M
     Note: breakpoint 2 also set at pc 0x4007a0.^M
     Breakpoint 3 at 0x4007a0: file gdb/testsuite/gdb.reverse/finish-reverse.c, line 44.
     (gdb) PASS: gdb.reverse/finish-reverse-bkpt.exp: set breakpoint at void_func's entry
     reverse-finish^M
     Run back to call of #0  void_func () at gdb/testsuite/gdb.reverse/finish-reverse.c:44
     main (argc=1, argv=0x7ffffffb78) at gdb/testsuite/gdb.reverse/finish-reverse.c:98
     98        void_func ();                                 /* call to void_func */^M
     (gdb) FAIL: gdb.reverse/finish-reverse-bkpt.exp: reverse-finish from void_func trips breakpoint at entry
    
    The test assumes that brekapoints on "void_func" and "*void_func" are
    set on different places because of function prologue.  However, on
    aarch64-linux, there is no prologue in void_func, so two breakpoints
    are set at the same place (0x4007a0).
    
    (gdb) disassemble void_func
    Dump of assembler code for function void_func:
       0x00000000004007a0 <+0>:	adrp	x0, 0x410000
       0x00000000004007a4 <+4>:	add	x0, x0, #0xc14
       0x00000000004007a8 <+8>:	mov	w1, #0x1
       0x00000000004007ac <+12>:	str	w1, [x0]
       0x00000000004007b0 <+16>:	ret
    
    The fix to this problem is to single step forward before setting
    breakpoint on *void_func.
    
    gdb/testsuite:
    
    2016-04-07  Yao Qi  <yao.qi@linaro.org>
    
    	* gdb.reverse/finish-reverse-bkpt.exp: Use temporary breakpoint.
    	Execute "si" command.

Diff:
---
 gdb/testsuite/ChangeLog                           | 5 +++++
 gdb/testsuite/gdb.reverse/finish-reverse-bkpt.exp | 9 +++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index a044d5a..e00afa7 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2016-04-07  Yao Qi  <yao.qi@linaro.org>
 
+	* gdb.reverse/finish-reverse-bkpt.exp: Use temporary breakpoint.
+	Execute "si" command.
+
+2016-04-07  Yao Qi  <yao.qi@linaro.org>
+
 	* gdb.reverse/next-reverse-bkpt-over-sr.exp: Match the breakpoint
 	number instead of the comments on some line.
 
diff --git a/gdb/testsuite/gdb.reverse/finish-reverse-bkpt.exp b/gdb/testsuite/gdb.reverse/finish-reverse-bkpt.exp
index ccc332d..1dff8e1 100644
--- a/gdb/testsuite/gdb.reverse/finish-reverse-bkpt.exp
+++ b/gdb/testsuite/gdb.reverse/finish-reverse-bkpt.exp
@@ -40,11 +40,16 @@ if [supports_process_record] {
 }
 
 set breakloc [gdb_get_line_number "VOID FUNC" "$srcfile"]
-gdb_test "break void_func" \
-    "Breakpoint $decimal at .*$srcfile, line $breakloc\." \
+gdb_test "tbreak void_func" \
+    "Temporary breakpoint $decimal at .*$srcfile, line $breakloc\." \
     "set breakpoint on void_func"
 gdb_continue_to_breakpoint "void_func" ".*$srcfile:$breakloc.*"
 
+# We stop at the brekapoint on void_func, but breakpoint on
+# *void_func will be set at the same place if function void_func doesn't
+# have prologue.  One step forward to avoid this.
+gdb_test "si"
+
 gdb_test "break \*void_func" \
     "Breakpoint $decimal at .*" \
     "set breakpoint at void_func's entry"