| Summary: | modf, modff, modfl: help GCC with argument checking | ||
|---|---|---|---|
| Product: | glibc | Reporter: | Bruno Haible <bruno> |
| Component: | math | Assignee: | Andreas Jaeger <aj> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | drepper.fsp |
| Priority: | P2 | Flags: | fweimer:
security-
|
| Version: | 2.11 | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
Thanks. I send a patch to libc-alpha for this. Changed in git. |
The second argument of the functions modf, modff, modfl must not be a NULL pointer, according to POSIX, and the glibc implementation also does not allow a NULL pointer. It would be useful to allow GCC to give a warning when someone passes a NULL literal to these functions. How to reproduce: ==================== foo.c ======================== #include <math.h> #include <stddef.h> int main () { return ! modf (2.4, NULL); } =================================================== $ gcc -Wall foo.c Expected result: foo.c: In function 'main': foo.c:6:3: warning: null argument where non-null required (argument 2) Actual result: No diagnostic. The fix should be easy: Add a properly conditionalized __attribute__ ((__nonnull__ (2))) to glibc/math/bits/mathcalls.h line 116.