[Mesa-dev] [PATCH 3/3] glsl: Fix forward NULL dereference coverity warning

[Iago Toral]

Ian, you wrote the original code, so you might want to have a look at
this one just in case I missed something even if piglit does not
complain. In any case, I guess that either the code or the comment
should be fixed.

Iago

On Mon, 2015-09-28 at 12:59 +0200, Iago Toral Quiroga wrote:
> The comment says that it should be impossible for decl_type to be NULL
> here, so don't try to handle the case where it is, simply add an assert.
> 
> >>>     CID 1324977:  Null pointer dereferences  (FORWARD_NULL)
> >>>     Comparing "decl_type" to null implies that "decl_type" might be null.
> 
> No piglit regressions observed.
> ---
>  src/glsl/ast_to_hir.cpp | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
> index b8d66dd..1259d50 100644
> --- a/src/glsl/ast_to_hir.cpp
> +++ b/src/glsl/ast_to_hir.cpp
> @@ -5732,17 +5732,16 @@ ast_process_structure_or_interface_block(exec_list *instructions,
>            * is_interface case, will have resulted in compilation having
>            * already halted due to a syntax error.
>            */
> -         const struct glsl_type *field_type =
> -            decl_type != NULL ? decl_type : glsl_type::error_type;
> +         assert(decl_type);
>  
> -         if (is_interface && field_type->contains_opaque()) {
> +         if (is_interface && decl_type->contains_opaque()) {
>              YYLTYPE loc = decl_list->get_location();
>              _mesa_glsl_error(&loc, state,
>                               "uniform/buffer in non-default interface block contains "
>                               "opaque variable");
>           }
>  
> -         if (field_type->contains_atomic()) {
> +         if (decl_type->contains_atomic()) {
>              /* From section 4.1.7.3 of the GLSL 4.40 spec:
>               *
>               *    "Members of structures cannot be declared as atomic counter
> @@ -5753,7 +5752,7 @@ ast_process_structure_or_interface_block(exec_list *instructions,
>                               "shader storage block or uniform block");
>           }
>  
> -         if (field_type->contains_image()) {
> +         if (decl_type->contains_image()) {
>              /* FINISHME: Same problem as with atomic counters.
>               * FINISHME: Request clarification from Khronos and add
>               * FINISHME: spec quotation here.
> @@ -5784,8 +5783,8 @@ ast_process_structure_or_interface_block(exec_list *instructions,
>                               "to struct or interface block members");
>           }
>  
> -         field_type = process_array_type(&loc, decl_type,
> -                                         decl->array_specifier, state);
> +         const struct glsl_type *field_type =
> +            process_array_type(&loc, decl_type, decl->array_specifier, state);
>           fields[i].type = field_type;
>           fields[i].name = decl->identifier;
>           fields[i].location = -1;