dprintf-posix, fprintf-posix: Avoid test failures with ASAN

[Bruno Haible]

With the clang17 address sanitizer and UB sanitizer, I'm seeing these two
test failures:

FAIL: test-dprintf-posix2.sh
FAIL: test-fprintf-posix3.sh

The cause is that the malloc (10000000) call returns NULL. The test cannot
work in this circumstance.


2024-05-09  Bruno Haible  <br...@clisp.org>

        dprintf-posix, fprintf-posix: Avoid test failures with ASAN.
        * tests/test-dprintf-posix2.c (main): Skip the test if ASAN is enabled.
        * tests/test-fprintf-posix3.c (main): Likewise.
        * tests/test-dprintf-posix2.sh: Update.
        * tests/test-fprintf-posix3.sh: Likewise.

diff --git a/tests/test-dprintf-posix2.c b/tests/test-dprintf-posix2.c
index 8eb8643762..3263072ebd 100644
--- a/tests/test-dprintf-posix2.c
+++ b/tests/test-dprintf-posix2.c
@@ -20,6 +20,21 @@
 
 #include <stdio.h>
 
+/* Skip this test when an address sanitizer is in use, since it would fail.  */
+#ifndef __has_feature
+# define __has_feature(a) 0
+#endif
+#if defined __SANITIZE_ADDRESS__ || __has_feature (address_sanitizer)
+
+int
+main ()
+{
+  fprintf (stderr, "Skipping test: address sanitizer's malloc behaves 
differently\n");
+  return 80;
+}
+
+#else
+
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -92,7 +107,7 @@ main (int argc, char *argv[])
       if (memory == NULL)
         return 1;
       memset (memory, 17, MAX_ALLOC_TOTAL);
-      result = 80;
+      result = 81;
     }
   else
     {
@@ -117,3 +132,5 @@ main (int argc, char *argv[])
 
   return result;
 }
+
+#endif /* ! address sanitizer enabled */
diff --git a/tests/test-dprintf-posix2.sh b/tests/test-dprintf-posix2.sh
index 7a548188f3..12e25bc318 100755
--- a/tests/test-dprintf-posix2.sh
+++ b/tests/test-dprintf-posix2.sh
@@ -4,7 +4,7 @@
 
 (${CHECKER} ./test-dprintf-posix2${EXEEXT} 0
  result=$?
- if test $result != 77 && test $result != 79 && test $result != 80; then 
result=1; fi
+ if test $result != 77 && test $result != 79 && test $result != 80 && test 
$result != 81; then result=1; fi
  exit $result
 ) 2>/dev/null
 malloc_result=$?
@@ -16,6 +16,10 @@ if test $malloc_result = 79; then
   echo "Skipping test: cannot trust address space size when running under QEMU"
   exit 77
 fi
+if test $malloc_result = 80; then
+  echo "Skipping test: address sanitizer's malloc behaves differently"
+  exit 77
+fi
 
 ${CHECKER} ./test-dprintf-posix2${EXEEXT} 1 > /dev/null
 result=$?
@@ -27,7 +31,7 @@ if test $result != 0; then
   exit 1
 fi
 
-if test $malloc_result = 80; then
+if test $malloc_result = 81; then
   echo "Skipping test: get_rusage_as() doesn't work"
   exit 77
 fi
diff --git a/tests/test-fprintf-posix3.c b/tests/test-fprintf-posix3.c
index 3a2ba7f926..f2d31e71ac 100644
--- a/tests/test-fprintf-posix3.c
+++ b/tests/test-fprintf-posix3.c
@@ -38,6 +38,21 @@ main ()
 
 #else
 
+/* Skip this test when an address sanitizer is in use, since it would fail.  */
+#ifndef __has_feature
+# define __has_feature(a) 0
+#endif
+#if defined __SANITIZE_ADDRESS__ || __has_feature (address_sanitizer)
+
+int
+main ()
+{
+  fprintf (stderr, "Skipping test: address sanitizer's malloc behaves 
differently\n");
+  return 80;
+}
+
+#else
+
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -109,7 +124,7 @@ main (int argc, char *argv[])
       if (memory == NULL)
         return 1;
       memset (memory, 17, MAX_ALLOC_TOTAL);
-      result = 80;
+      result = 81;
     }
   else
     {
@@ -135,4 +150,5 @@ main (int argc, char *argv[])
   return result;
 }
 
+#endif /* ! address sanitizer enabled */
 #endif /* !macOS */
diff --git a/tests/test-fprintf-posix3.sh b/tests/test-fprintf-posix3.sh
index a79273ee2e..2fe1f27d40 100755
--- a/tests/test-fprintf-posix3.sh
+++ b/tests/test-fprintf-posix3.sh
@@ -4,7 +4,7 @@
 
 (${CHECKER} ./test-fprintf-posix3${EXEEXT} 0
  result=$?
- if test $result != 77 && test $result != 78 && test $result != 79 && test 
$result != 80; then result=1; fi
+ if test $result != 77 && test $result != 78 && test $result != 79 && test 
$result != 80 && test $result != 81; then result=1; fi
  exit $result
 ) 2>/dev/null
 malloc_result=$?
@@ -20,6 +20,10 @@ if test $malloc_result = 79; then
   echo "Skipping test: cannot trust address space size when running under QEMU"
   exit 77
 fi
+if test $malloc_result = 80; then
+  echo "Skipping test: address sanitizer's malloc behaves differently"
+  exit 77
+fi
 
 ${CHECKER} ./test-fprintf-posix3${EXEEXT} 1 > /dev/null
 result=$?