[Mesa-dev] [PATCH] glsl: add null pointer check in print_without_declaration()

[Brian Paul]

On 03/31/2017 12:01 AM, Nicolai Hähnle wrote:
> On 31.03.2017 05:21, Brian Paul wrote:
>> To avoid/fix a segmentation fault when running the stand-alone GLSL
>> compiler utility for cases such as the Mesa demos toyball test:
>>
>> glsl_compiler --dump-builder --version 120 CH11-toyball.vert
>> CH11-toyball.frag
>> ---
>>  src/compiler/glsl/ir_builder_print_visitor.cpp | 4 +++-
>>  1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/compiler/glsl/ir_builder_print_visitor.cpp
>> b/src/compiler/glsl/ir_builder_print_visitor.cpp
>> index 825dbe1..164a237 100644
>> --- a/src/compiler/glsl/ir_builder_print_visitor.cpp
>> +++ b/src/compiler/glsl/ir_builder_print_visitor.cpp
>> @@ -581,7 +581,9 @@
>> ir_builder_print_visitor::print_without_declaration(const
>> ir_expression *ir)
>>           const struct hash_entry *const he =
>>              _mesa_hash_table_search(index_map, ir->operands[i]);
>>
>> -         print_without_indent("r%04X", (unsigned)(uintptr_t) he->data);
>> +         if (he) {
>> +            print_without_indent("r%04X", (unsigned)(uintptr_t)
>> he->data);
>> +         }
>
> Is the output still usable in this case? I don't quite understand the
> use case and how this case can happen.

I didn't dig either and would appreciate any feedback.  I'm merely 
trying to avoid a segfault (found while debugging the MinGW optimization 
issue).

-Brian