mpaland/printf

Mark the variadic *printf functions with __attribute__((format)).

svkampen opened this issue · 2 comments

svkampen commented

The format attribute marks a variadic function as taking a format string and corresponding arguments which should be type-checked against the format string. Marking printf_, sprintf_, etc. this way allows compilers to issue warnings when the supplied arguments do not have the correct type, as they would for the standard library functions.

The code change is very small, and currently implemented in svkampen@ba025a5 svkampen@d8aeaa9 (see comments below). I've guarded the __attribute__ declarations with #ifdef __GNUC__ ... #endif, so that they don't interfere with compilers that don't support them.

joshklod commented

The v*printf-style functions can also be marked using

format(<archetype>, <string-index>, 0)

to check the format string itself for errors. See the same link.

svkampen commented

Thanks, I must have glossed over that while reading the documentation... I've updated my branch - svkampen@d8aeaa9 now contains the attributes for all of the functions.

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