[Mesa-dev] [PATCH v2 2/2] glsl: raise warning when using uninitialized variables

[Alejandro Piñeiro]

I will take a look to this one today.

Thanks for pointing it

On 18/04/16 00:47, Ilia Mirkin wrote:
> On Mon, Mar 28, 2016 at 2:50 PM, Alejandro Piñeiro <apinheiro at igalia.com> wrote:
>> v2:
>>  * Take into account out varyings too (Timothy Arceri)
>>  * Fix style (Timothy Arceri)
>>  * Use a new ast_expression variable, instead of an
>>    ast_expression::hir new parameter (Timothy Arceri)
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94129
>> ---
>>  src/compiler/glsl/ast_to_hir.cpp | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
>> index eb45f29..e38ab10 100644
>> --- a/src/compiler/glsl/ast_to_hir.cpp
>> +++ b/src/compiler/glsl/ast_to_hir.cpp
>> @@ -1901,6 +1901,13 @@ ast_expression::do_hir(exec_list *instructions,
>>        if (var != NULL) {
>>           var->data.used = true;
>>           result = new(ctx) ir_dereference_variable(var);
>> +
>> +         if ((var->data.mode == ir_var_auto || var->data.mode == ir_var_shader_out)
>> +             && !this->is_lhs
>> +             && result->variable_referenced()->data.assigned != true) {
>> +            _mesa_glsl_warning(&loc, state, "`%s' used uninitialized",
>> +                               this->primary_expression.identifier);
> This also appears to warn in the case of
>
> void foo(out float x) { x = 1.0; }
>
> float bar;
> foo(bar);
>
> It thinks that bar is being used uninitialized. How do we fix this? It
> happens a ton in Talos Principle.
>
>   -ilia
>