https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97774
Bug ID: 97774
Summary: Incorrect line info for try/catch
Product: gcc
Version: 7.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
[ This PR is FTR, it's already fixed. ]
Consider this test-case, minimized from gdb.cp/gdb9593.cc (
https://src.fedoraproject.org/rpms/gdb/blob/master/f/gdb-archer-vla-tests.patch
):
...
$ cat -n test.cc
1 void
2 function1 (void)
3 {
4 throw 20;
5 }
6
7 int
8 main (void)
9 {
10 try
11 {
12 function1 ();
13 }
14 catch (int x)
15 {
16 }
17
18 return 0;
19 }
...
We compile using gcc 7.5.0:
...
$ g++ -g test.cc -save-temps -dA
...
When trying to step over function1 using next, we end up on line 18, and not at
the start of line 18 (given the $hex prefix):
...
$ gdb a.out -ex start -ex next
Reading symbols from a.out...
Temporary breakpoint 1 at 0x4007b5: file test.cc, line 12.
Starting program: a.out
Temporary breakpoint 1, main () at test.cc:12
12 function1 ();
0x00000000004007c1 18 return 0;
(gdb)
...
This is caused by the following.
There's a .loc for line 18 after the call to function1, but then we jump away
to label .L9:
...
# test.cc:12
.loc 1 12 0
call _Z9function1v
.LEHE0:
# BLOCK 3 seq:1
# PRED: 2 (FALLTHRU) 6 [100.0%]
.L7:
# test.cc:18
.loc 1 18 0
movl $0, %eax
# SUCC: 7 [100.0%]
jmp .L9
# BLOCK 4 seq:2
# PRED: 2 (ABNORMAL,ABNORMAL_CALL,EH)
.L8:
cmpq $1, %rdx
...
Since there's no other loc before the insn at .L8, it's considered to be part
of line 18.
