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Fix string/tester.c build with GCC 8 [committed]
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Cc: <msebor at gmail dot com>
- Date: Tue, 14 Nov 2017 17:53:14 +0000
- Subject: Fix string/tester.c build with GCC 8 [committed]
- Authentication-results: sourceware.org; auth=none
GCC 8 warns about more cases of string functions truncating their
output or not copying a trailing NUL byte.
This patch fixes testsuite build failures caused by such warnings in
string/tester.c. In general, the warnings are disabled around the
relevant calls using DIAG_* macros, since the relevant cases are being
deliberately tested. In one case, the warning is with
-Wstringop-overflow= instead of -Wstringop-truncation; in that case,
the conditional is __GNUC_PREREQ (7, 0) (being the version where
-Wstringop-overflow= was introduced), to allow the conditional to be
removed sooner, since it's harmless to disable the warning for a
GCC version where it doesn't actually occur. In the case of warnings
for strncpy calls in test_memcmp, the calls in question are changed to
use memcpy, as they don't copy a trailing NUL and the point of that
code is to test memcmp rather than strncpy.
Tested (compilation) with GCC 8 for x86_64-linux-gnu with
build-many-glibcs.py (in conjunction with Martin's patch to allow
glibc to build). Committed.
2017-11-14 Joseph Myers <joseph@codesourcery.com>
* string/tester.c (test_stpncpy): Disable -Wstringop-truncation
for stpncpy calls for GCC 8.
(test_strncat): Disable -Wstringop-truncation warning for strncat
calls for GCC 8. Disable -Wstringop-overflow= warning for one
strncat call for GCC 7.
(test_strncpy): Disable -Wstringop-truncation warning for strncpy
calls for GCC 8.
(test_memcmp): Use memcpy instead of strncpy for calls not copying
trailing NUL.
diff --git a/string/tester.c b/string/tester.c
index 4b928b4..66b1151 100644
--- a/string/tester.c
+++ b/string/tester.c
@@ -264,8 +264,15 @@ test_stpncpy (void)
{
it = "stpncpy";
memset (one, 'x', sizeof (one));
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+ /* GCC 8 warns about stpncpy truncating output; this is deliberately
+ tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
check (stpncpy (one, "abc", 2) == one + 2, 1);
check (stpncpy (one, "abc", 3) == one + 3, 2);
+ DIAG_POP_NEEDS_COMMENT;
check (stpncpy (one, "abc", 4) == one + 3, 3);
check (one[3] == '\0' && one[4] == 'x', 4);
check (stpncpy (one, "abcd", 5) == one + 4, 5);
@@ -420,13 +427,27 @@ test_strncat (void)
equal (one, "cd", 9);
(void) strcpy (one, "ab");
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+ /* GCC 8 warns about strncat truncating output; this is deliberately
+ tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
(void) strncat (one, "cdef", 2);
+ DIAG_POP_NEEDS_COMMENT;
equal (one, "abcd", 10); /* Count-limited. */
(void) strncat (one, "gh", 0);
equal (one, "abcd", 11); /* Zero count. */
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (7, 0)
+ /* GCC 8 warns about strncat bound equal to source length; this is
+ deliberately tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-overflow=");
+#endif
(void) strncat (one, "gh", 2);
+ DIAG_POP_NEEDS_COMMENT;
equal (one, "abcdgh", 12); /* Count and length equal. */
DIAG_PUSH_NEEDS_COMMENT;
@@ -523,11 +544,25 @@ test_strncpy (void)
equal (one, "abc", 2); /* Did the copy go right? */
(void) strcpy (one, "abcdefgh");
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+ /* GCC 8 warns about strncpy truncating output; this is deliberately
+ tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
(void) strncpy (one, "xyz", 2);
+ DIAG_POP_NEEDS_COMMENT;
equal (one, "xycdefgh", 3); /* Copy cut by count. */
(void) strcpy (one, "abcdefgh");
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+ /* GCC 8 warns about strncpy truncating output; this is deliberately
+ tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
(void) strncpy (one, "xyz", 3); /* Copy cut just before NUL. */
+ DIAG_POP_NEEDS_COMMENT;
equal (one, "xyzdefgh", 4);
(void) strcpy (one, "abcdefgh");
@@ -542,7 +577,14 @@ test_strncpy (void)
equal (one+5, "fgh", 9);
(void) strcpy (one, "abc");
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (8, 0)
+ /* GCC 8 warns about strncpy truncating output; this is deliberately
+ tested here. */
+ DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-truncation");
+#endif
(void) strncpy (one, "xyz", 0); /* Zero-length copy. */
+ DIAG_POP_NEEDS_COMMENT;
equal (one, "abc", 10);
(void) strncpy (one, "", 2); /* Zero-length source. */
@@ -1151,8 +1193,8 @@ test_memcmp (void)
{
char *a = one + i;
char *b = two + i;
- strncpy(a, "--------11112222", 16);
- strncpy(b, "--------33334444", 16);
+ memcpy(a, "--------11112222", 16);
+ memcpy(b, "--------33334444", 16);
check(memcmp(b, a, 16) > 0, cnt++);
check(memcmp(a, b, 16) < 0, cnt++);
}
--
Joseph S. Myers
joseph@codesourcery.com