How can I run GCC/Clang for static analysis? (warnings only)

Question

Without compiling code, I would like GCC or Clang to report warnings.
Is it possible to run the compiler for static analysis only?
I can't find a way to pass the compiler warning flags and tell it not to compile.

edit: just found that clang has a static analyser

@KerrekSB perfect! thank you – Trevor Hickey Dec 28 '12 at 16:51 — Trevor Hickey, Dec 28 '12 at 16:51
@KerrekSB: Move it to answer :) – Jack Dec 28 '12 at 19:25 — Jack, Dec 28 '12 at 19:25

score 17 · Accepted Answer · answered Dec 28 '12 at 20:44

17

Both GCC and Clang have an option -fsyntax-only that makes the compiler only perform syntax checking without any actual compilation.

answered Dec 28 '12 at 20:44

Kerrek SB

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However it's important to note that the flag is a lot more useful for clang, for G++ it doesn't do template instantiation, which means lots of possible diagnostics are missed – Jonathan Wakely Dec 28 '12 at 22:06

score 3 · Answer 2 · answered Dec 29 '12 at 09:18

In addition to the other replies, gcc is doing some analysis during compilation (and even during some optimization passes). So you could discard the generated code and still get all the warnings with e.g. gcc -Wall -O -c code.c -o /dev/null

Notice that you could extend GCC with your additional passes doing some additional, application specific, checks and warnings, e.g. with MELT (a high level domain specific language to extend GCC).

If you want strong static analysis and are willing to give additional annotations for that purpose consider also Frama C.

How can I run GCC/Clang for static analysis? (warnings only)

2 Answers2

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