diff options
Diffstat (limited to 'make.h')
| -rw-r--r-- | make.h | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -299,6 +299,17 @@ extern char *alloca (); # endif /* HAVE_ALLOCA_H. */ #endif /* GCC. */ +/* ISDIGIT offers the following features: + - Its arg may be any int or unsigned int; it need not be an unsigned char. + - It's guaranteed to evaluate its argument exactly once. + NOTE! Make relies on this behavior, don't change it! + - It's typically faster. + Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that + only '0' through '9' are digits. Prefer ISDIGIT to isdigit() unless + it's important to use the locale's definition of `digit' even when the + host does not conform to Posix. */ +#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9) + #ifndef iAPX286 # define streq(a, b) \ ((a) == (b) || \ |