Re:Was the iOS SSL Flaw Deliberate?
by hengheng on Thursday February 27, 2014 @11:03AM
(#7312872)
Honest question, what are decent tools to find bugs like this in C code nowadays? I was saddened to read that gcc cannot check for unreachable code.
[ Parent
| on HN ]
The -Wunreachable-code flag does work in clang, to some extent at least (I have a rather old version here so YMMV). Other tools that may help:
The clang static analyzer: http://clang-analyzer.llvm.org
Valgrind: http://www.valgrind.org
Address Sanitizer: http://clang.llvm.org/docs/AddressSanitizer.html
The various -fsanitize options in clang (undefined behaviours, integer overflows etc): http://clang.llvm.org/docs/UsersManual.html#id28
There is a list here:
http://en.wikipedia.org/wiki/List_of_tools_for_static_code_a...
Also there is oclint not listed there, which is pretty amazing, but it has a strange notation for ignoring wqrnings. splint is pretty good too though and still supports the legacy lint stuff like /* NOTREACHED /
BSD lint seems to work still (though it looks like the lintlib is no longer built on FreeBSD and stdlib is not lint clean!) but even it would have caught this gotofail:
01: #include <stdlib.h>
02:
03: int
04: main(int argc, char *argv[])
05: {
06: if (argc == 0)
07: goto fail;
08: goto fail;
09:
10: exit(0);
11:
12:
13: fail:
14: exit(1);
15: }
$ lint a.c
a.c:
stdlib.h(286): warning: ANSI C does not support 'long long' [265]
stdlib.h(287): warning: ANSI C does not support 'long long' [265]
stdlib.h(287): warning: ANSI C does not support 'long long' [265]
a.c(10): warning: statement not reached [193]
a.c(15): warning: function main falls off bottom without returning value [217]
a.c(4): warning: argument argv unused in function main [231]
_types.h(61): warning: struct __timer never defined [233]
_types.h(62): warning: struct __mq never defined [233]
lint: cannot find llib-lc.ln
Lint pass2:
exit used( a.c(10) ), but not defined
$ cc a.c
$ ./a.out
$ echo $?
1