[gcc/devel/omp/gcc-16] OpenMP: Add omp_get_device_distances routine: Gracefully handle failure to open Linux sysfs file for

https://gcc.gnu.org/g:566ad013548bd977f29f4b677a16867af71e33e4

commit 566ad013548bd977f29f4b677a16867af71e33e4
Author: Thomas Schwinge <[email protected]>
Date:   Tue Jun 30 08:55:08 2026 +0200

    OpenMP: Add omp_get_device_distances routine: Gracefully handle failure to open Linux sysfs file for NUMA node [PR125877]
    
    Fix-up for commit 8af1592882509fbead16e30fd2d056330a9609e4
    "OpenMP: Add omp_get_device_distances routine [PR125877]".  Without this,
    'libgomp/config/linux/numa.c:gomp_get_numa_distance' faults when trying to
    'fscanf' from the null pointer upon 'fopen' failure.
    
            PR libgomp/125877
            libgomp/
            * config/linux/numa.c (gomp_get_numa_distance): Gracefully handle
            failure to open Linux sysfs file for NUMA node.
    
    (cherry picked from commit c1c66ede4052c2697f3dd17b80f8b80ff3fc2368)

Diff:
---
 libgomp/config/linux/numa.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libgomp/config/linux/numa.c b/libgomp/config/linux/numa.c
index d43b34b98dd1..a3d84870e6e8 100644
--- a/libgomp/config/linux/numa.c
+++ b/libgomp/config/linux/numa.c
@@ -85,6 +85,11 @@ gomp_get_numa_distance (int node1, int node2)
 	    return -1;
 	  int distance = -1;
 	  FILE *in = fopen (filename, "r");
+	  if (!in)
+	    {
+	      free (numa_distances);
+	      return -1;
+	    }
 	  for (int j = 0; j < cnt; j++)
 	    {
 	      fscanf (in, "%d", &distance);