testsuite: i386 regression for funcargs.exp

3ca22649a6dfeb71058c33be4d0542b98f1f0ff5 is the first bad commit
commit 3ca22649a6dfeb71058c33be4d0542b98f1f0ff5
Author: Simon Marchi <simon.marchi@polymtl.ca>
Date:   Mon Dec 21 12:51:54 2015 -0500
    Remove HP-UX references fom testsuite
@@ -1013,13 +1013,6 @@ proc localvars_in_indirect_call { } {
     #

     gdb_test_multiple "finish" "finish from indirectly called function" {
-       -re "\\(\\*pointer_to_call0a\\) \\(c, s, i, l\\);.*First.*$gdb_prompt $" {
-           #On hppa2.0w-hp-hpux11.00, gdb finishes at one line earlier than
-           #hppa1.1-hp-hpux11.00. Therefore, an extra "step" is necessary
-           #to continue the test.
-           send_gdb "step\n"
-           exp_continue
-	}
        -re ".*\\(\\*pointer_to_call0a\\) \\(c, s, i, l\\);.*Second.*$gdb_prompt $" {
            pass "finish from indirectly called function"
       	}

->

 finish^M
 Run till exit from #0  call0a (c=97 'a', s=1, i=2, l=3) at ./gdb.base/funcargs.c:82^M
 0x0804a189 in main () at ./gdb.base/funcargs.c:583^M
 583	  (*pointer_to_call0a) (c, s, i, l);    /* First step into call0a.  */^M
-(gdb) step^M
-584	  (*pointer_to_call0a) (c, s, i, l);    /* Second step into call0a.  */^M
-(gdb) PASS: gdb.base/funcargs.exp: finish from indirectly called function
+(gdb) FAIL: gdb.base/funcargs.exp: finish from indirectly called function
 step^M
-call0a (c=97 'a', s=1, i=2, l=3) at ./gdb.base/funcargs.c:82^M
-82	  c = 'a';^M
-(gdb) PASS: gdb.base/funcargs.exp: stepping into indirectly called function
+584	  (*pointer_to_call0a) (c, s, i, l);    /* Second step into call0a.  */^M
+(gdb) FAIL: gdb.base/funcargs.exp: stepping into indirectly called function

At least on x86_64 with testsuite in -m32 (expecting native i386 would be the
same).

Pedro Alves:

The difference is that with newer GCC there's an extra instruction
after the call which is still assigned to line 583:

$ diff -up /tmp/4.8.3 /tmp/6.0.0 -U 1000
--- /tmp/4.8.3  2016-01-11 12:37:39.611089156 +0000
+++ /tmp/6.0.0  2016-01-11 13:21:00.021127976 +0000
@@ -1,27 +1,30 @@
 583       (*pointer_to_call0a) (c, s, i, l);    /* First step into call0a.  */
    mov    0x804d060,%ebx
    mov    0x804d050,%ecx
    movzwl 0x804d040,%eax
    movswl %ax,%edx
    movzbl 0x804d030,%eax
    movsbl %al,%eax
-   mov    %ebx,0xc(%esp)
-   mov    %ecx,0x8(%esp)
-   mov    %edx,0x4(%esp)
-   mov    %eax,(%esp)
-   mov    0x7c(%esp),%eax
+   push   %ebx
+   push   %ecx
+   push   %edx
+   push   %eax
+   mov    -0x1c(%ebp),%eax
    call   *%eax
+   add    $0x10,%esp

 584	   (*pointer_to_call0a) (c, s, i, l);    /* Second step into call0a.  */
    mov    0x804d060,%ebx
    mov    0x804d050,%ecx
    movzwl 0x804d040,%eax
    movswl %ax,%edx
    movzbl 0x804d030,%eax
    movsbl %al,%eax
-   mov    %ebx,0xc(%esp)
-   mov    %ecx,0x8(%esp)
-   mov    %edx,0x4(%esp)
-   mov    %eax,(%esp)
-   mov    0x7c(%esp),%eax
+   push   %ebx
+   push   %ecx
+   push   %edx
+   push   %eax
+   mov    -0x1c(%ebp),%eax
    call   *%eax
+   add    $0x10,%esp
+

I don't know why -m32 changed to push/add instead of mov while 64-bit hasn't.

This is most likely needed on non-x86 ports as well.

gdb/testsuite/ChangeLog
2016-01-11  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* gdb.base/funcargs.exp (finish from indirectly called function):
	Reintroduce the case for 'First'.

1 files changed, 7 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/funcargs.exp b/gdb/testsuite/gdb.base/funcargs.exp
index e5b6ced..792ca9e 100644
--- a/gdb/testsuite/gdb.base/funcargs.exp
+++ b/gdb/testsuite/gdb.base/funcargs.exp
@@ -1013,6 +1013,13 @@ proc localvars_in_indirect_call { } {
     #
 
     gdb_test_multiple "finish" "finish from indirectly called function" {
+	-re "\\(\\*pointer_to_call0a\\) \\(c, s, i, l\\);.*First.*$gdb_prompt $" {
+	    # If the branch instruction is not the last instruction in the
+	    # function call line, we'll stop at that line, and need an extra
+	    # "step" to continue the test.
+	    send_gdb "step\n"
+	    exp_continue
+	}
 	-re ".*\\(\\*pointer_to_call0a\\) \\(c, s, i, l\\);.*Second.*$gdb_prompt $" {
 	    pass "finish from indirectly called function"
 	}