[mptre]

The first argument to mmap() was marked as direction="in", causing constParameterPointer to suggest declaring it as pointer to const. However, with MAP_FIXED any existing mapping at addr is replaced, so the pointed-to memory is effectively modified. Drop the direction from the first argument of mmap() in bsd.cfg and posix.cfg, and mmap64() in posix.cfg.

[dmcppcheck]

AI review

The fix is incomplete. cfg/gnu.cfg also defines mmap (around line 1989), and its arg 1 still has direction="in". When gnu.cfg is loaded, the false positive is still reported: with --library=gnu, and also with --library=posix --library=gnu and --library=gnu --library=posix. On Linux, gnu.cfg is normally loaded, so most users of this check will still get the warning. The fix needs the same one-line change in gnu.cfg and a matching test in test/cfg/gnu.c. mmap64 is fixed in every load order, since only posix.cfg defines it.

The change also removes a false uninitvar on char buf[100]; mmap(buf, ...), which is a good side effect. Uninitialized pointer arguments are still reported. I found no other problems.

Testing

I built cppcheck from both pr/ and base/.

test/cfg/runtests.sh passes for posix.c, bsd.c and gnu.c on the PR build. pkg-config is missing here, so the script skipped its compiler syntax checks.

Test file scratch/t1.c:

#include <sys/mman.h>
void f1(void *addr) {
    (void)mmap(addr, 0x1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, 0, 0);
}
void f2(char *addr) {
    (void)mmap64(addr, 0x1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, 0, 0);
}
void f4(void) {
    char buf[100];
    (void)mmap(buf, 0x1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, 0, 0);
}
void f5(void) {
    char *p;
    (void)mmap(p, 0x1000, PROT_READ, MAP_PRIVATE | MAP_FIXED, 0, 0);
}

Results:

• --library=posix and --library=bsd: the PR fixes constParameterPointer for f1 and f2. The constVariable/uninitvar warnings on buf go away, and uninitvar on p is still reported.
• gnu.cfg loaded: the false positive remains. Command and output:

$ pr/cppcheck -q --enable=style --library=gnu t1.c
t1.c:2:15: style: Parameter 'addr' can be declared as pointer to const [constParameterPointer]
t1.c:12:10: style: Variable 'buf' can be declared as const array [constVariable]
t1.c:13:16: error: Uninitialized variable: buf [uninitvar]

• --library=posix --library=gnu (either order): the PR still reports constParameterPointer for f1 (mmap), but no longer for f2 (mmap64). The output for f1 is the same as in base.

---

Automated review of 4a06233 by Claude. The pull request was built and tested locally.

[mptre]

Sorry, fix pushed.

[dmcppcheck]

AI review

I found no new problems. The earlier review said cfg/gnu.cfg also needed the fix, and the PR now has it. The constParameterPointer false positive on the addr argument of mmap()/mmap64() is gone with posix, bsd and gnu, and with posix,gnu and gnu,posix loaded together. uninitvar on an uninitialized pointer passed as addr is still reported.

Testing

• Build: I built cppcheck in pr/ with make -j8 cppcheck. It built cleanly.

• cfg tests: bash test/cfg/runtests.sh test/cfg/posix.c, test/cfg/bsd.c and test/cfg/gnu.c all printed SUCCESS and exited with 0. The script skipped its compiler syntax checks because pkg-config is not installed here.

• Scratch test: scratch/t.c has these functions:

  • void f1(void *addr) calls mmap(addr, ..., MAP_FIXED, ...).
  • void f2(char *addr) calls mmap64(addr, ...).
  • f3 passes an uninitialized char *p to mmap.
  • f4 stores the mmap result in a local.

  I ran pr/cppcheck -q --enable=style --library=X t.c with X = posix, bsd, gnu, posix,gnu and gnu,posix.

• Results:

  • No constParameterPointer is reported for f1 or f2 with any of these.
  • uninitvar on p in f3 is still reported every time.
  • The posix leak checks (leakReturnValNotUsed, memleak) still work.

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Automated review of 634e4ed by Claude. The pull request was built and tested locally.