HLSL: regression test for library-mode emission (#2626)

This removes the need for a special case for default_entry_point and correctly handles exports that call other exports.

Author: castano

reference/shaders-hlsl/asm/lib/multi-export.asm.lib

@@ -0,0 +1,17 @@
+uint add_one(uint x)
+{
+    return x + 1u;
+}
+
+uint helper_add(uint a, uint b)
+{
+    return a + b;
+}
+
+uint add_two(uint y)
+{
+    uint _22 = y;
+    uint _23 = 2u;
+    return helper_add(_22, _23);
+}
+

shaders-hlsl/asm/lib/multi-export.asm.lib

@@ -0,0 +1,54 @@
+; SPIR-V
+; Version: 1.5
+; Generator: Khronos SPIR-V Tools Assembler; 0
+; Bound: 40
+; Schema: 0
+               OpCapability Linkage
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpSource HLSL 630
+               OpName %add_one "add_one"
+               OpName %x "x"
+               OpName %add_two "add_two"
+               OpName %y "y"
+               OpName %helper_add "helper_add"
+               OpName %a "a"
+               OpName %b "b"
+               OpDecorate %add_one LinkageAttributes "add_one" Export
+               OpDecorate %add_two LinkageAttributes "add_two" Export
+       %uint = OpTypeInt 32 0
+     %uint_1 = OpConstant %uint 1
+     %uint_2 = OpConstant %uint 2
+%_ptr_Function_uint = OpTypePointer Function %uint
+       %fn1 = OpTypeFunction %uint %_ptr_Function_uint
+       %fn2 = OpTypeFunction %uint %_ptr_Function_uint %_ptr_Function_uint
+
+ %helper_add = OpFunction %uint None %fn2
+          %a = OpFunctionParameter %_ptr_Function_uint
+          %b = OpFunctionParameter %_ptr_Function_uint
+       %h_bb = OpLabel
+       %h_av = OpLoad %uint %a
+       %h_bv = OpLoad %uint %b
+      %h_sum = OpIAdd %uint %h_av %h_bv
+               OpReturnValue %h_sum
+               OpFunctionEnd
+
+    %add_one = OpFunction %uint None %fn1
+          %x = OpFunctionParameter %_ptr_Function_uint
+       %o_bb = OpLabel
+       %o_xv = OpLoad %uint %x
+        %o_r = OpIAdd %uint %o_xv %uint_1
+               OpReturnValue %o_r
+               OpFunctionEnd
+
+    %add_two = OpFunction %uint None %fn1
+          %y = OpFunctionParameter %_ptr_Function_uint
+       %t_bb = OpLabel
+     %t_arg1 = OpVariable %_ptr_Function_uint Function
+     %t_arg2 = OpVariable %_ptr_Function_uint Function
+       %t_yv = OpLoad %uint %y
+               OpStore %t_arg1 %t_yv
+               OpStore %t_arg2 %uint_2
+        %t_r = OpFunctionCall %uint %helper_add %t_arg1 %t_arg2
+               OpReturnValue %t_r
+               OpFunctionEnd

test_shaders.py

@@ -470,6 +470,11 @@ def validate_shader_hlsl(shader, force_no_external_validation, paths):
         test_glslang = False
     if '.task' in shader or '.mesh' in shader:
         test_glslang = False
+    if shader_is_library(shader):
+        # Library HLSL output has no entry point; glslangValidator's -e main
+        # would fail. Skip the round-trip — the output is meant to be
+        # included by HLSL/GLSL source rather than compiled standalone.
+        test_glslang = False
 
     hlsl_args = [paths.glslang, '--amb', '-e', 'main', '-D', '--target-env', 'vulkan1.1', '-V', shader]
     if '.sm30.' in shader:
@@ -522,7 +527,12 @@ def cross_compile_hlsl(shader, spirv, opt, force_no_external_validation, iterati
     spirv_16 = '.spv16.' in shader
     spirv_14 = '.spv14.' in shader
 
-    if spirv_16:
+    if shader_is_library(shader):
+        # Library modules use the Linkage capability, which is rejected
+        # by Vulkan target envs. Use a universal/spv target instead.
+        spirv_env = 'spv1.5'
+        glslang_env = 'spirv1.5'
+    elif spirv_16:
         spirv_env = 'spv1.6'
         glslang_env = 'vulkan1.3'
     elif spirv_14:
@@ -551,7 +561,14 @@ def cross_compile_hlsl(shader, spirv, opt, force_no_external_validation, iterati
 
     sm = shader_to_sm(shader)
 
-    hlsl_args = [spirv_cross_path, '--entry', 'main', '--output', hlsl_path, spirv_path, '--hlsl-enable-compat', '--hlsl', '--shader-model', sm, '--iterations', str(iterations)]
+    # Library SPIR-V modules (e.g. dxc -T lib_6_*) have no OpEntryPoint;
+    # skip the --entry flag for those so spirv-cross does not try to
+    # select an entry point that does not exist.
+    is_library = shader_is_library(shader)
+    hlsl_args = [spirv_cross_path]
+    if not is_library:
+        hlsl_args += ['--entry', 'main']
+    hlsl_args += ['--output', hlsl_path, spirv_path, '--hlsl-enable-compat', '--hlsl', '--shader-model', sm, '--iterations', str(iterations)]
     if '.line.' in shader:
         hlsl_args.append('--emit-line-directives')
     if '.flatten.' in shader:
@@ -845,6 +862,12 @@ def shader_is_eliminate_dead_variables(shader):
 def shader_is_spirv(shader):
     return '.asm.' in shader
 
+def shader_is_library(shader):
+    # SPIR-V library module: no OpEntryPoint, exports declared via
+    # OpDecorate ... LinkageAttributes ... Export. Recognised by the
+    # `.lib` filename suffix (e.g. foo.asm.lib).
+    return shader.endswith('.lib')
+
 def shader_is_invalid_spirv(shader):
     return '.invalid.' in shader