[igt-dev] [PATCH i-g-t 1/1] lib: Help static analyzers figure out the execution flow

[Daniel Vetter]

On Tue, Oct 30, 2018 at 04:15:08PM +0200, Petri Latvala wrote:
> When running any kind of static analysis on IGT, one tends to drown in
> warnings about using uninitialized variables in subtests, because
> static analysis is unable to figure out that igt_fixture blocks are
> always entered if a subtest block is entered. Aid the discovery of
> correct execution flow by making static analysis always enter all
> igt_fixture blocks and all subtest blocks.
> 
> Automatic discovery of static analyzers is done for Clang, Coverity
> and Klocwork, using macros found by quick googling. For explicit
> control on possible other analyzers, defining STATIC_ANALYSIS_BUILD=1
> manually will activate this hack.
> 
> Signed-off-by: Petri Latvala <petri.latvala at intel.com>

I guess if it helps, this makes sense.

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
> lib/igt_core.h | 25 ++++++++++++++++++-------
>  1 file changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/igt_core.h b/lib/igt_core.h
> index b80e1702..0f643f6b 100644
> --- a/lib/igt_core.h
> +++ b/lib/igt_core.h
> @@ -46,6 +46,14 @@
>  #endif
>  
>  
> +#ifndef STATIC_ANALYSIS_BUILD
> +#if defined(__clang_analyzer__) || defined(__COVERITY__) || defined(__KLOCWORK__)
> +#define STATIC_ANALYSIS_BUILD 1
> +#else
> +#define STATIC_ANALYSIS_BUILD 0
> +#endif
> +#endif
> +
>  extern const char* __igt_test_description __attribute__((weak));
>  extern bool __igt_plain_output;
>  extern char *igt_frame_dump_path;
> @@ -109,9 +117,10 @@ void __igt_fixture_end(void) __attribute__((noreturn));
>   * blocks should be annotated with igt_fixture.
>   */
>  #define igt_fixture for (volatile int igt_tokencat(__tmpint,__LINE__) = 0; \
> +                         STATIC_ANALYSIS_BUILD || ( \
>  			 igt_tokencat(__tmpint,__LINE__) < 1 && \
>  			 __igt_fixture() && \
> -			 (sigsetjmp(igt_subtest_jmpbuf, 1) == 0); \
> +			 (sigsetjmp(igt_subtest_jmpbuf, 1) == 0)); \
>  			 igt_tokencat(__tmpint,__LINE__) ++, \
>  			 __igt_fixture_complete())
>  
> @@ -169,15 +178,17 @@ bool __igt_run_subtest(const char *subtest_name);
>   *
>   * This is a simpler version of igt_subtest_f()
>   */
> -#define igt_subtest(name) for (; __igt_run_subtest((name)) && \
> -				   (sigsetjmp(igt_subtest_jmpbuf, 1) == 0); \
> -				   igt_success())
> +#define igt_subtest(name) for (; STATIC_ANALYSIS_BUILD ||		\
> +				       (__igt_run_subtest((name)) &&	\
> +					(sigsetjmp(igt_subtest_jmpbuf, 1) == 0)); \
> +                                  igt_success())
>  #define __igt_subtest_f(tmp, format...) \
>  	for (char tmp [256]; \
> -	     snprintf( tmp , sizeof( tmp ), \
> +	     STATIC_ANALYSIS_BUILD || \
> +	     ((snprintf( tmp , sizeof( tmp ), \
>  		      format), \
> -	     __igt_run_subtest( tmp ) && \
> -	     (sigsetjmp(igt_subtest_jmpbuf, 1) == 0); \
> +	       __igt_run_subtest( tmp )) && \
> +	      (sigsetjmp(igt_subtest_jmpbuf, 1) == 0)); \
>  	     igt_success())
>  
>  /**
> -- 
> 2.18.0
> 
> _______________________________________________
> igt-dev mailing list
> igt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/igt-dev

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch