[Mesa-dev] [PATCH 2/4] glsl: trivial change of the file extension matching

[Ian Romanick]

On 05/30/2017 03:45 PM, Vlad Golovkin wrote:
> ---
>  src/compiler/glsl/standalone.cpp | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/src/compiler/glsl/standalone.cpp b/src/compiler/glsl/standalone.cpp
> index 52554bb92a..b9cee23642 100644
> --- a/src/compiler/glsl/standalone.cpp
> +++ b/src/compiler/glsl/standalone.cpp
> @@ -459,19 +459,22 @@ standalone_compile_shader(const struct standalone_options *_options,
>        if (len < 6)
>           goto fail;
>  
> -      const char *const ext = & files[i][len - 5];
> +      const char *ext = & files[i][len - 5];
>        /* TODO add support to read a .shader_test */
> -      if (strncmp(".vert", ext, 5) == 0 || strncmp(".glsl", ext, 5) == 0)
> +      if (*ext != '.')
> +         goto fail;
> +      ++ext;
> +      if (memcmp("vert", ext, 4) == 0 || memcmp("glsl", ext, 4) == 0)

This is not the same.  If ext points at a NUL character that is, say, at
the end of page, you don't get to look at the next 3 bytes, and memcmp
may well do that.  There is no guarantee that memcmp will not access
beyond the first mismatched byte.

>  	 shader->Type = GL_VERTEX_SHADER;
> -      else if (strncmp(".tesc", ext, 5) == 0)
> +      else if (memcmp("tesc", ext, 4) == 0)
>  	 shader->Type = GL_TESS_CONTROL_SHADER;
> -      else if (strncmp(".tese", ext, 5) == 0)
> +      else if (memcmp("tese", ext, 4) == 0)
>  	 shader->Type = GL_TESS_EVALUATION_SHADER;
> -      else if (strncmp(".geom", ext, 5) == 0)
> +      else if (memcmp("geom", ext, 4) == 0)
>  	 shader->Type = GL_GEOMETRY_SHADER;
> -      else if (strncmp(".frag", ext, 5) == 0)
> +      else if (memcmp("frag", ext, 4) == 0)
>  	 shader->Type = GL_FRAGMENT_SHADER;
> -      else if (strncmp(".comp", ext, 5) == 0)
> +      else if (memcmp("comp", ext, 4) == 0)
>           shader->Type = GL_COMPUTE_SHADER;
>        else
>           goto fail;
>