SPIR-V/Vulkan specialization constants are not generated in SPIRV when -allow-glsl is set

[andreasschultes]

SPIR-V/Vulkan specialization constants are not generated in SPIRV when -allow-glsl is set.

${SLANGC} ${SHADER_FILE} -target spirv -I${SOURCE_ROOT} ${SHADER_INCLUDE_DIRS} -DdebugPrintfEXT -depfile ${SPIRV}.d -o ${SPIRV}

generates the SpecId "OpDecorate %a SpecId 5"

${SLANGC} ${SHADER_FILE} -target spirv -allow-glsl -I${SOURCE_ROOT} ${SHADER_INCLUDE_DIRS} -DdebugPrintfEXT -depfile ${SPIRV}.d -o ${SPIRV}

uses the default values and the constants are optimised out

[csyonghe]

Can you share with us the shader code that canbe used to reproduce this issue?

[andreasschultes]

The test case for specialization constants reproduce this with the parameter -target spirv -allow-glsl -o test.spv
https://github.com/shader-slang/slang/blob/master/tests/spirv/specialization-constant.slang