[Bug gdb/28426] Step reverse over line with multiple executable statements

["vries at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=28426

Tom de Vries <vries at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vries at gcc dot gnu.org

--- Comment #1 from Tom de Vries <vries at gcc dot gnu.org> ---
Created attachment 14415
  --> https://sourceware.org/bugzilla/attachment.cgi?id=14415&action=edit
reproduce.sh

I've written a reproducer script reproducer.sh (generating test.c and gdb.in)
based on comment #0.

I first tried with gcc 7.5.0, but that one does not emit column info by
default, so I added -gcolumn-info:
...
$ gcc -g test.c ; readelf -wl a.out | grep -i column
$
$ gcc -g test.c -gcolumn-info ; readelf -wl a.out | grep -i column
  [0x0000010f]  Set column to 1
  [0x0000011d]  Set column to 7
  [0x00000120]  Set column to 8
  [0x00000125]  Set column to 20
  [0x00000128]  Set column to 8
  [0x0000012c]  Set column to 10
  [0x0000012f]  Set column to 1
...

Then, I used "b *main" to start at line 2 (otherwise, on x86_64-linux, it
starts at line 3).

Still, it doesn't reproduce for me with current trunk and x86_64-linux:
...
$ ./reproduce.sh
  ...
+b *main
Breakpoint 1 at 0x400497: file test.c, line 2.
+run

Breakpoint 1, main () at test.c:2
2       {
+record
+target record-full
+step
3         int b[2] = {5,8};
+step
5         b[0] = 1;
+step
6         b[1] = 2;
+step
8         b[0] = 6;   b[1] = 9;         /* generic statement, end part two */
+step
10        b[1] = 10;
+step
11        b[0] = 20;
+step
13        return 0;
+set exec-dir reverse
+step
11        b[0] = 20;
+step
10        b[1] = 10;
+step
8         b[0] = 6;   b[1] = 9;         /* generic statement, end part two */
+step
6         b[1] = 2;
+step
5         b[0] = 1;
+step
3         int b[2] = {5,8};
+step

No more reverse-execution history.
main () at test.c:2
2       {
...
in other words, after 7 steps forward and 7 steps back I end up at the same
point where I started: line 2.

That's both with gcc 7.5.0 and gcc 12.2.1.

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