diff options
| -rw-r--r-- | ChangeLog | 12 | ||||
| -rw-r--r-- | include/libc-internal.h | 31 | ||||
| -rw-r--r-- | stdio-common/bug21.c | 9 | ||||
| -rw-r--r-- | stdio-common/scanf14.c | 21 |
4 files changed, 73 insertions, 0 deletions
@@ -1,3 +1,15 @@ +2014-12-10 Joseph Myers <joseph@codesourcery.com> + + * include/libc-internal.h (DIAG_PUSH_NEEDS_COMMENT): New macro. + (DIAG_POP_NEEDS_COMMENT): Likewise. + (_DIAG_STR1): Likewise. + (_DIAG_STR): Likewise. + (DIAG_IGNORE_NEEDS_COMMENT): Likewise. + * stdio-common/bug21.c: Include <libc-internal.h>. + (do_test): Disable -Wformat around call to sscanf. + * stdio-common/scanf14.c: Include <libc-internal.h>. + (main): Disable -Wformat around some calls to scanf functions. + 2014-12-09 Torvald Riegel <triegel@redhat.com> * sysdeps/unix/sysv/linux/sh/pthread_once.S: Remove file. diff --git a/include/libc-internal.h b/include/libc-internal.h index 2ced1c1..bca59a4 100644 --- a/include/libc-internal.h +++ b/include/libc-internal.h @@ -76,4 +76,35 @@ extern void __init_misc (int, char **, char **); #define ignore_value(x) \ ({ __typeof__ (x) __ignored_value = (x); (void) __ignored_value; }) +/* The macros to control diagnostics are structured like this, rather + than a single macro that both pushes and pops diagnostic state and + takes the affected code as an argument, because the GCC pragmas + work by disabling the diagnostic for a range of source locations + and do not work when all the pragmas and the affected code are in a + single macro expansion. */ + +/* Push diagnostic state. */ +#define DIAG_PUSH_NEEDS_COMMENT _Pragma ("GCC diagnostic push") + +/* Pop diagnostic state. */ +#define DIAG_POP_NEEDS_COMMENT _Pragma ("GCC diagnostic pop") + +#define _DIAG_STR1(s) #s +#define _DIAG_STR(s) _DIAG_STR1(s) + +/* Ignore the diagnostic OPTION. VERSION is the most recent GCC + version for which the diagnostic has been confirmed to appear in + the absence of the pragma (in the form MAJOR.MINOR for GCC 4.x, + just MAJOR for GCC 5 and later). Uses of this pragma should be + reviewed when the GCC version given is no longer supported for + building glibc; the version number should always be on the same + source line as the macro name, so such uses can be found with grep. + Uses should come with a comment giving more details of the + diagnostic, and an architecture on which it is seen if possibly + optimization-related and not in architecture-specific code. This + macro should only be used if the diagnostic seems hard to fix (for + example, optimization-related false positives). */ +#define DIAG_IGNORE_NEEDS_COMMENT(version, option) \ + _Pragma (_DIAG_STR (GCC diagnostic ignored option)) + #endif /* _LIBC_INTERNAL */ diff --git a/stdio-common/bug21.c b/stdio-common/bug21.c index d22b9c1..ca27272 100644 --- a/stdio-common/bug21.c +++ b/stdio-common/bug21.c @@ -1,4 +1,5 @@ #include <stdio.h> +#include <libc-internal.h> static int do_test (void) @@ -6,7 +7,15 @@ do_test (void) static const char buf[] = " "; char *str; + /* GCC in C99 mode treats %a as the C99 format expecting float *, + but glibc with _GNU_SOURCE treats %as as the GNU allocation + extension, so resulting in "warning: format '%a' expects argument + of type 'float *', but argument 3 has type 'char **'". This + applies to the other %as, %aS and %a[] formats below as well. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat"); int r = sscanf (buf, "%as", &str); + DIAG_POP_NEEDS_COMMENT; printf ("%d %p\n", r, str); return r != -1 || str != NULL; diff --git a/stdio-common/scanf14.c b/stdio-common/scanf14.c index 6ca5c7c..cffccb0 100644 --- a/stdio-common/scanf14.c +++ b/stdio-common/scanf14.c @@ -2,6 +2,7 @@ #include <stdlib.h> #include <string.h> #include <wchar.h> +#include <libc-internal.h> #define FAIL() \ do { \ @@ -23,6 +24,13 @@ main (void) FAIL (); else if (f != 0.25 || memcmp (c, "s x", 3) != 0) FAIL (); + /* GCC in C99 mode treats %a as the C99 format expecting float *, + but glibc with _GNU_SOURCE treats %as as the GNU allocation + extension, so resulting in "warning: format '%a' expects argument + of type 'float *', but argument 3 has type 'char **'". This + applies to the other %as, %aS and %a[] formats below as well. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat"); if (sscanf (" 1.25s x", "%as%2c", &sp, c) != 2) FAIL (); else @@ -32,10 +40,14 @@ main (void) memset (sp, 'x', sizeof "1.25s"); free (sp); } + DIAG_POP_NEEDS_COMMENT; if (sscanf (" 2.25s x", "%las%2c", &d, c) != 2) FAIL (); else if (d != 2.25 || memcmp (c, " x", 2) != 0) FAIL (); + /* See explanation above. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat"); if (sscanf (" 3.25S x", "%4aS%3c", &lsp, c) != 2) FAIL (); else @@ -54,6 +66,7 @@ main (void) memset (sp, 'x', sizeof "4.25"); free (sp); } + DIAG_POP_NEEDS_COMMENT; if (sscanf ("5.25[0-9.] x", "%la[0-9.]%2c", &d, c) != 2) FAIL (); else if (d != 5.25 || memcmp (c, " x", 2) != 0) @@ -82,6 +95,9 @@ main (void) FAIL (); if (fseek (fp, 0, SEEK_SET) != 0) FAIL (); + /* See explanation above. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat"); if (fscanf (fp, "%as%2c", &sp, c) != 2) FAIL (); else @@ -91,11 +107,15 @@ main (void) memset (sp, 'x', sizeof "1.25s"); free (sp); } + DIAG_POP_NEEDS_COMMENT; if (freopen (fname, "r", stdin) == NULL) FAIL (); else { + /* See explanation above. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wformat"); if (scanf ("%as%2c", &sp, c) != 2) FAIL (); else @@ -105,6 +125,7 @@ main (void) memset (sp, 'x', sizeof "1.25s"); free (sp); } + DIAG_POP_NEEDS_COMMENT; } fclose (fp); |