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| author | Eric Blake <eblake@redhat.com> | 2020-06-29 11:28:04 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-07-10 18:02:18 -0400 |
| commit | 6553aa1d1166b4257f1294b898fc9f09e7276639 (patch) | |
| tree | 7ff7b21a4d7d41b6c0b69687fbd9d3e2523e259a /include/qemu/osdep.h | |
| parent | b16c0e20c74218f2d69710cedad11da7dd4d2190 (diff) | |
| download | qemu-6553aa1d1166b4257f1294b898fc9f09e7276639.zip qemu-6553aa1d1166b4257f1294b898fc9f09e7276639.tar.gz qemu-6553aa1d1166b4257f1294b898fc9f09e7276639.tar.bz2 | |
coverity: provide Coverity-friendly MIN_CONST and MAX_CONST
Coverity has problems seeing through __builtin_choose_expr, which
result in it abandoning analysis of later functions that utilize a
definition that used MIN_CONST or MAX_CONST, such as in qemu-file.c:
50 DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
CID 1429992 (#1 of 1): Unrecoverable parse warning (PARSE_ERROR)1.
expr_not_constant: expression must have a constant value
As has been done in the past (see 07d66672), it's okay to dumb things
down when compiling for static analyzers. (Of course, now the
syntax-checker has a false positive on our reference to
__COVERITY__...)
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: CID 1429992, CID 1429995, CID 1429997, CID 1429999
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200629162804.1096180-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/qemu/osdep.h')
| -rw-r--r-- | include/qemu/osdep.h | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 0d26a1b..0fc206a 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -250,7 +250,8 @@ extern int daemon(int, int); * Note that neither form is usable as an #if condition; if you truly * need to write conditional code that depends on a minimum or maximum * determined by the pre-processor instead of the compiler, you'll - * have to open-code it. + * have to open-code it. Sadly, Coverity is severely confused by the + * constant variants, so we have to dumb things down there. */ #undef MIN #define MIN(a, b) \ @@ -258,22 +259,28 @@ extern int daemon(int, int); typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ _a < _b ? _a : _b; \ }) -#define MIN_CONST(a, b) \ - __builtin_choose_expr( \ - __builtin_constant_p(a) && __builtin_constant_p(b), \ - (a) < (b) ? (a) : (b), \ - ((void)0)) #undef MAX #define MAX(a, b) \ ({ \ typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ _a > _b ? _a : _b; \ }) -#define MAX_CONST(a, b) \ + +#ifdef __COVERITY__ +# define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) +# define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) +#else +# define MIN_CONST(a, b) \ + __builtin_choose_expr( \ + __builtin_constant_p(a) && __builtin_constant_p(b), \ + (a) < (b) ? (a) : (b), \ + ((void)0)) +# define MAX_CONST(a, b) \ __builtin_choose_expr( \ __builtin_constant_p(a) && __builtin_constant_p(b), \ (a) > (b) ? (a) : (b), \ ((void)0)) +#endif /* * Minimum function that returns zero only if both values are zero. |