Re: [PATCH] Guard longjmp in test to not inf loop [PR114720]

[Richard Biener]

On Mon, Apr 15, 2024 at 2:35 PM Jørgen Kvalsvik  wrote:
>
> Guard the longjmp to not infinitely loop. The longjmp (jump) function is
> called unconditionally to make test flow simpler, but the jump
> destination would return to a point in main that would call longjmp
> again. The longjmp is really there to exercise the then-branch of
> setjmp, to verify coverage is accurately counted in the presence of
> complex edges.

OK

> PR gcov-profile/114720
>
> gcc/testsuite/ChangeLog:
>
> * gcc.misc-tests/gcov-22.c: Guard longjmp to not loop.
> ---
>  gcc/testsuite/gcc.misc-tests/gcov-22.c | 14 +-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/gcc/testsuite/gcc.misc-tests/gcov-22.c 
> b/gcc/testsuite/gcc.misc-tests/gcov-22.c
> index 641791a7223..7ca78467ca3 100644
> --- a/gcc/testsuite/gcc.misc-tests/gcov-22.c
> +++ b/gcc/testsuite/gcc.misc-tests/gcov-22.c
> @@ -87,7 +87,19 @@ setdest ()
>  void
>  jump ()
>  {
> -longjmp (dest, 1);
> +/* Protect the longjmp so it will only be done once.  The whole purpose 
> of
> +   this function is to help test conditions and instrumentation around
> +   setjmp and its complex edges, as both branches should count towards
> +   coverage, even when one is taken through longjmp.  If the jump is not
> +   guarded it can cause an infinite loop as setdest returns to a point in
> +   main before jump (), leading to an infinite loop.  See PR
> +   gcov-profile/114720.  */
> +static int called_once = 0;
> +if (!called_once) /* conditions(suppress) */
> +{
> +   called_once = 1;
> +   longjmp (dest, 1);
> +}
>  }
>
>  int
> --
> 2.30.2
>

[PATCH] Guard longjmp in test to not inf loop [PR114720]

[Jørgen Kvalsvik]

Guard the longjmp to not infinitely loop. The longjmp (jump) function is
called unconditionally to make test flow simpler, but the jump
destination would return to a point in main that would call longjmp
again. The longjmp is really there to exercise the then-branch of
setjmp, to verify coverage is accurately counted in the presence of
complex edges.

PR gcov-profile/114720

gcc/testsuite/ChangeLog:

* gcc.misc-tests/gcov-22.c: Guard longjmp to not loop.
---
 gcc/testsuite/gcc.misc-tests/gcov-22.c | 14 +-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.misc-tests/gcov-22.c 
b/gcc/testsuite/gcc.misc-tests/gcov-22.c
index 641791a7223..7ca78467ca3 100644
--- a/gcc/testsuite/gcc.misc-tests/gcov-22.c
+++ b/gcc/testsuite/gcc.misc-tests/gcov-22.c
@@ -87,7 +87,19 @@ setdest ()
 void
 jump ()
 {
-longjmp (dest, 1);
+/* Protect the longjmp so it will only be done once.  The whole purpose of
+   this function is to help test conditions and instrumentation around
+   setjmp and its complex edges, as both branches should count towards
+   coverage, even when one is taken through longjmp.  If the jump is not
+   guarded it can cause an infinite loop as setdest returns to a point in
+   main before jump (), leading to an infinite loop.  See PR
+   gcov-profile/114720.  */
+static int called_once = 0;
+if (!called_once) /* conditions(suppress) */
+{
+   called_once = 1;
+   longjmp (dest, 1);
+}
 }
 
 int
-- 
2.30.2