spirv-link generates invalid debug ids with non semantic shader debug info

[danginsburg]

I have two valid SPIR-V files (pass spirv-val) with non-semantic shader debug info that when linked together with spirv-link generate invalid SPIR-V with the following error:

error: line 6093: ID '5071[%5071]' has not been defined
  %5070 = OpExtInst %void %1 DebugLine %449 %465 %465 %5071 %_arr_v2float_int_3

This leads to a crash later on when I run the spirv-opt aggressive DCE pass on it. I am unable to provide the shaders publicly, but I will provide them in private to @jeremy-lunarg. I'm filing the issue publicly so that it is tracked.

The repro steps are:

spirv-link test_spirv_link_0.spv test_spirv_link_1.spv --create-library -o test.spv
spirv-val test.spv
error: line 6093: ID '5071[%5071]' has not been defined
  %5070 = OpExtInst %void %1 DebugLine %449 %465 %465 %5071 %_arr_v2float_int_3

[pierremoreau]

Yes, there is an issue where the code updating the IDs does not run on debug-line instructions. I have a fix ready, but still need to add new tests to validate it.

[pierremoreau]

@jeremy-lunarg I won’t have time to finish the MR tonight, but if you want to give the fix a try locally, you simply need to change this line to }, true);.