utils: fix --flags/--thissystem when using a fake fsroot or cpuid directory

fsroot and cpuid are implemented in tools using environment variables
(those debug cases are not in the API since v2).
Those backends forced by environment variable override the normal
topology thissystem flag that may be set with set_flags() in the API
and with --flags or --thissystem in cli tools. One must use the
HWLOC_THISSYSTEM envvar to force the this system flag.
Implement this automatically in the tools (common helpers).

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

Author: bgoglin

utils/hwloc/hwloc-calc.c

@@ -255,7 +255,7 @@ int main(int argc, char *argv[])
     hwloc_topology_set_all_types_filter(topology, HWLOC_TYPE_FILTER_KEEP_ALL); \
     hwloc_topology_set_flags(topology, flags); \
     if (input) { \
-      err = hwloc_utils_enable_input_format(topology, input, &input_format, verbose, callname); \
+      err = hwloc_utils_enable_input_format(topology, flags, input, &input_format, verbose, callname); \
       if (err) return EXIT_FAILURE; \
     } \
     err = hwloc_topology_load(topology); \

utils/hwloc/hwloc-distrib.c

@@ -200,7 +200,7 @@ int main(int argc, char *argv[])
     cpuset = malloc(n * sizeof(hwloc_bitmap_t));
 
     if (input) {
-      err = hwloc_utils_enable_input_format(topology, input, &input_format, verbose, callname);
+      err = hwloc_utils_enable_input_format(topology, flags, input, &input_format, verbose, callname);
       if (err) {
 	free(cpuset);
 	return EXIT_FAILURE;

utils/hwloc/hwloc-info.c

@@ -524,7 +524,7 @@ main (int argc, char *argv[])
   hwloc_topology_set_flags(topology, flags);
 
   if (input) {
-    err = hwloc_utils_enable_input_format(topology, input, &input_format, verbose_mode, callname);
+    err = hwloc_utils_enable_input_format(topology, flags, input, &input_format, verbose_mode, callname);
     if (err)
       return err;
   }

utils/hwloc/misc.h

@@ -217,7 +217,7 @@ hwloc_utils_autodetect_input_format(const char *input, int verbose)
 }
 
 static __hwloc_inline int
-hwloc_utils_enable_input_format(struct hwloc_topology *topology,
+hwloc_utils_enable_input_format(struct hwloc_topology *topology, unsigned long flags,
 				const char *input,
 				enum hwloc_utils_input_format *input_format,
 				int verbose, const char *callname)
@@ -258,6 +258,9 @@ hwloc_utils_enable_input_format(struct hwloc_topology *topology,
       fprintf(stderr, "Cannot force linux component first because HWLOC_COMPONENTS environment variable is already set to %s.\n", env);
     else
       putenv((char *) "HWLOC_COMPONENTS=linux,pci,stop");
+    /* normally-set flags are overriden by envvar-forced backends */
+    if (flags & HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM)
+      putenv((char *) "HWLOC_THISSYSTEM=1");
 #else /* HWLOC_LINUX_SYS */
     fprintf(stderr, "This installation of hwloc does not support changing the file-system root, sorry.\n");
     exit(EXIT_FAILURE);
@@ -280,6 +283,9 @@ hwloc_utils_enable_input_format(struct hwloc_topology *topology,
       fprintf(stderr, "Cannot force x86 component first because HWLOC_COMPONENTS environment variable is already set to %s.\n", env);
     else
       putenv((char *) "HWLOC_COMPONENTS=x86,stop");
+    /* normally-set flags are overriden by envvar-forced backends */
+    if (flags & HWLOC_TOPOLOGY_FLAG_IS_THISSYSTEM)
+      putenv((char *) "HWLOC_THISSYSTEM=1");
 #else
     fprintf(stderr, "This installation of hwloc does not support loading from a cpuid dump, sorry.\n");
     exit(EXIT_FAILURE);

utils/lstopo/lstopo.c

@@ -1126,7 +1126,7 @@ main (int argc, char *argv[])
   }
 
   if (input) {
-    err = hwloc_utils_enable_input_format(topology, input, &input_format, loutput.verbose_mode > 1, callname);
+    err = hwloc_utils_enable_input_format(topology, flags, input, &input_format, loutput.verbose_mode > 1, callname);
     if (err)
       goto out_with_topology;
   }