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| author | Arnaud Lacombe <lacombar@gmail.com> | 2011-11-23 13:05:53 -0500 |
|---|---|---|
| committer | Michal Marek <mmarek@suse.cz> | 2012-01-15 00:17:18 +0100 |
| commit | 37ae2d5998aa29d8bf52f124199a21341bc6d18d (patch) | |
| tree | 95cb787bfcb7340caaa1f20513b3f22edef886aa /scripts | |
| parent | e2aef4d33ac43ec45e4fc2903288030d7f464832 (diff) | |
| download | lwn-37ae2d5998aa29d8bf52f124199a21341bc6d18d.tar.gz lwn-37ae2d5998aa29d8bf52f124199a21341bc6d18d.zip | |
kbuild: Fix compiler warning with assertion when calling 'fwrite'
Reinhard Tartler discovered a corner case of calling xfwrite() where the
length of the string is zero.
Arnaud Lacombe suggested to use assertion for the corner case, as
fwrite(3) is currently used:
1) in comment printers. Empty comment are not allowed.
2) in a callback passed to expr_print(), where the string printed is
either NULL OR non-empty.
3) in the lexer, auto-generated, and unused.
I feel using assertion is a good solution:
1) It cleanly takes care of the above-mentioned corner case.
2) It can be easily disabled by defining NDEBUG.
3) It asserts xfwrite() is simply a wrapper for fwrite().
Reported-by: Reinhard Tartler <Reinhard.Tartler@informatik.uni-erlangen.de>
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/kconfig/expr.h | 1 | ||||
| -rw-r--r-- | scripts/kconfig/lkc.h | 6 |
2 files changed, 5 insertions, 2 deletions
diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 80fce57080cc..d4ecce8bc3a6 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -10,6 +10,7 @@ extern "C" { #endif +#include <assert.h> #include <stdio.h> #ifndef __cplusplus #include <stdbool.h> diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h index b633bdb9f3d4..c18f2bd9c095 100644 --- a/scripts/kconfig/lkc.h +++ b/scripts/kconfig/lkc.h @@ -90,8 +90,10 @@ struct conf_printer { /* confdata.c and expr.c */ static inline void xfwrite(const void *str, size_t len, size_t count, FILE *out) { - if (fwrite(str, len, count, out) < count) - fprintf(stderr, "\nError in writing or end of file.\n"); + assert(len != 0); + + if (fwrite(str, len, count, out) != count) + fprintf(stderr, "Error in writing or end of file.\n"); } /* menu.c */ |