Add GL_EXT_texture_shadow_lod support

Closes #3302.

Test/baseResults/spv.ext.texture_shadow_lod.error.frag.out

@@ -0,0 +1,6 @@
+spv.ext.texture_shadow_lod.error.frag
+ERROR: 0:11: 'textureLod' : required extension not requested: GL_EXT_texture_shadow_lod
+ERROR: 1 compilation errors.  No code generated.
+
+
+SPIR-V is not generated for failed compile or link

Test/baseResults/spv.ext.texture_shadow_lod.frag.out

@@ -0,0 +1,94 @@
+spv.ext.texture_shadow_lod.frag
+// Module Version 10000
+// Generated by (magic number): 8000b
+// Id's are bound by 59
+
+                              Capability Shader
+                              Capability SampledCubeArray
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "main" 8 16
+                              ExecutionMode 4 OriginUpperLeft
+                              Source GLSL 450
+                              SourceExtension  "GL_EXT_texture_shadow_lod"
+                              Name 4  "main"
+                              Name 8  "c"
+                              Name 12  "s2da"
+                              Name 16  "tc"
+                              Name 24  "sca"
+                              Name 47  "sc"
+                              Decorate 8(c) Location 0
+                              Decorate 12(s2da) DescriptorSet 0
+                              Decorate 12(s2da) Binding 0
+                              Decorate 16(tc) Location 0
+                              Decorate 24(sca) DescriptorSet 0
+                              Decorate 24(sca) Binding 1
+                              Decorate 47(sc) DescriptorSet 0
+                              Decorate 47(sc) Binding 2
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypePointer Output 6(float)
+            8(c):      7(ptr) Variable Output
+               9:             TypeImage 6(float) 2D depth array sampled format:Unknown
+              10:             TypeSampledImage 9
+              11:             TypePointer UniformConstant 10
+        12(s2da):     11(ptr) Variable UniformConstant
+              14:             TypeVector 6(float) 4
+              15:             TypePointer Input 14(fvec4)
+          16(tc):     15(ptr) Variable Input
+              18:    6(float) Constant 0
+              21:             TypeImage 6(float) Cube depth array sampled format:Unknown
+              22:             TypeSampledImage 21
+              23:             TypePointer UniformConstant 22
+         24(sca):     23(ptr) Variable UniformConstant
+              30:             TypeInt 32 1
+              31:             TypeVector 30(int) 2
+              32:     30(int) Constant 0
+              33:   31(ivec2) ConstantComposite 32 32
+              44:             TypeImage 6(float) Cube depth sampled format:Unknown
+              45:             TypeSampledImage 44
+              46:             TypePointer UniformConstant 45
+          47(sc):     46(ptr) Variable UniformConstant
+         4(main):           2 Function None 3
+               5:             Label
+              13:          10 Load 12(s2da)
+              17:   14(fvec4) Load 16(tc)
+              19:    6(float) CompositeExtract 17 3
+              20:    6(float) ImageSampleDrefImplicitLod 13 17 19 Bias 18
+                              Store 8(c) 20
+              25:          22 Load 24(sca)
+              26:   14(fvec4) Load 16(tc)
+              27:    6(float) ImageSampleDrefImplicitLod 25 26 18
+                              Store 8(c) 27
+              28:          10 Load 12(s2da)
+              29:   14(fvec4) Load 16(tc)
+              34:    6(float) CompositeExtract 29 3
+              35:    6(float) ImageSampleDrefImplicitLod 28 29 34 ConstOffset 33
+                              Store 8(c) 35
+              36:          10 Load 12(s2da)
+              37:   14(fvec4) Load 16(tc)
+              38:    6(float) CompositeExtract 37 3
+              39:    6(float) ImageSampleDrefImplicitLod 36 37 38 Bias ConstOffset 18 33
+                              Store 8(c) 39
+              40:          10 Load 12(s2da)
+              41:   14(fvec4) Load 16(tc)
+              42:    6(float) CompositeExtract 41 3
+              43:    6(float) ImageSampleDrefExplicitLod 40 41 42 Lod 18
+                              Store 8(c) 43
+              48:          45 Load 47(sc)
+              49:   14(fvec4) Load 16(tc)
+              50:    6(float) CompositeExtract 49 3
+              51:    6(float) ImageSampleDrefExplicitLod 48 49 50 Lod 18
+                              Store 8(c) 51
+              52:          22 Load 24(sca)
+              53:   14(fvec4) Load 16(tc)
+              54:    6(float) ImageSampleDrefExplicitLod 52 53 18 Lod 18
+                              Store 8(c) 54
+              55:          10 Load 12(s2da)
+              56:   14(fvec4) Load 16(tc)
+              57:    6(float) CompositeExtract 56 3
+              58:    6(float) ImageSampleDrefExplicitLod 55 56 57 Lod ConstOffset 18 33
+                              Store 8(c) 58
+                              Return
+                              FunctionEnd

Test/spv.ext.texture_shadow_lod.error.frag

@@ -0,0 +1,13 @@
+#version 450
+
+layout(binding = 0) uniform sampler2DArrayShadow s2da;
+
+layout(location = 0) out vec4 c_out;
+
+layout(location = 0) in vec4 tc;
+
+void main()
+{
+    float c = textureLod(s2da, tc, 0);
+    c_out = vec4(c);
+}

Test/spv.ext.texture_shadow_lod.frag

@@ -0,0 +1,21 @@
+#version 450
+#extension GL_EXT_texture_shadow_lod : enable
+
+layout(binding = 0) uniform sampler2DArrayShadow s2da;
+layout(binding = 1) uniform samplerCubeArrayShadow sca;
+layout(binding = 2) uniform samplerCubeShadow sc;
+
+layout(location = 0) out float c;
+
+layout(location = 0) in vec4 tc;
+
+void main() {
+    c = texture(s2da, tc, 0.0);
+    c = texture(sca, tc, 0.0, 0.0);
+    c = textureOffset(s2da, tc, ivec2(0.0));
+    c = textureOffset(s2da, tc, ivec2(0.0), 0.0);
+    c = textureLod(s2da, tc, 0.0);
+    c = textureLod(sc, tc, 0.0);
+    c = textureLod(sca, tc, 0.0, 0.0);
+    c = textureLodOffset(s2da, tc, 0.0, ivec2(0.0));
+}

glslang/MachineIndependent/Initialize.cpp

@@ -4820,6 +4820,33 @@ void TBuiltIns::initialize(int version, EProfile profile, const SpvVersion& spvV
             "\n");
     }
 
+    // GL_EXT_texture_shadow_lod overloads
+    if (profile == EEsProfile) { // ES
+        if (version >= 300) {
+            commonBuiltins.append("float texture(sampler2DArrayShadow, vec4, float);"
+                                  "float textureOffset(sampler2DArrayShadow, vec4, ivec2, float);"
+                                  "float textureLod(sampler2DArrayShadow, vec4, float);"
+                                  "float textureLodOffset(sampler2DArrayShadow, vec4, float, ivec2);"
+                                  "\n");
+        }
+        if (version >= 320) {
+            commonBuiltins.append("float texture(samplerCubeArrayShadow, vec4, float, float);"
+                                  "float textureLod(samplerCubeShadow, vec4, float);"
+                                  "float textureLod(samplerCubeArrayShadow, vec4, float, float);"
+                                  "\n");
+        }
+    } else if (version >= 130) { // Desktop
+        commonBuiltins.append("float texture(sampler2DArrayShadow, vec4, float);"
+                              "float texture(samplerCubeArrayShadow, vec4, float, float);"
+                              "float textureOffset(sampler2DArrayShadow, vec4, ivec2);"
+                              "float textureOffset(sampler2DArrayShadow, vec4, ivec2, float);"
+                              "float textureLod(sampler2DArrayShadow, vec4, float);"
+                              "float textureLod(samplerCubeShadow, vec4, float);"
+                              "float textureLod(samplerCubeArrayShadow, vec4, float, float);"
+                              "float textureLodOffset(sampler2DArrayShadow, vec4, float, ivec2);"
+                              "\n");
+    }
+
     //============================================================================
     //
     // Standard Uniforms
@@ -8741,6 +8768,36 @@ void TBuiltIns::identifyBuiltIns(int version, EProfile profile, const SpvVersion
             symbolTable.setFunctionExtensions("textureBlockMatchSADQCOM", 1, &E_GL_QCOM_image_processing);
             symbolTable.setFunctionExtensions("textureBlockMatchSSDQCOM", 1, &E_GL_QCOM_image_processing);
         }
+
+        // GL_EXT_texture_shadow_lod
+        // NOTE: These are the mangled names of individual overloads, since this extension adds overloads for
+        //       existing built-in functions.
+        if (profile == EEsProfile) {
+            if (version >= 300) {
+                symbolTable.setSingleFunctionExtensions("texture(sAS21;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("textureOffset(sAS21;vf4;vi2;f1;", 1,
+                                                        &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("textureLod(sAS21;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("textureLodOffset(sAS21;vf4;f1;vi2;", 1,
+                                                        &E_GL_EXT_texture_shadow_lod);
+            }
+            if (version >= 320) {
+                symbolTable.setSingleFunctionExtensions("texture(sASC1;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("texture(sASC1;vf4;f1;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("textureLod(sASC1;vf4;f1;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+                symbolTable.setSingleFunctionExtensions("textureLod(sSC1;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            }
+        } else if (version >= 130) {
+            symbolTable.setSingleFunctionExtensions("texture(sAS21;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("texture(sASC1;vf4;f1;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureOffset(sAS21;vf4;vi2;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureOffset(sAS21;vf4;vi2;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureLod(sAS21;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureLod(sASC1;vf4;f1;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureLod(sSC1;vf4;f1;", 1, &E_GL_EXT_texture_shadow_lod);
+            symbolTable.setSingleFunctionExtensions("textureLodOffset(sAS21;vf4;f1;vi2;", 1,
+                                                    &E_GL_EXT_texture_shadow_lod);
+        }
         break;
 
     case EShLangCompute:

glslang/MachineIndependent/SymbolTable.cpp

@@ -318,6 +318,16 @@ void TSymbolTableLevel::setFunctionExtensions(const char* name, int num, const c
     }
 }
 
+// Make a single function require an extension(s). i.e., this will only set the extensions for the symbol that matches 'name' exactly.
+// This is different from setFunctionExtensions, which uses std::map::lower_bound to effectively set all symbols that start with 'name'.
+// Should only be used for a version/profile that actually needs the extension(s).
+void TSymbolTableLevel::setSingleFunctionExtensions(const char* name, int num, const char* const extensions[])
+{
+    if (auto candidate = level.find(name); candidate != level.end()) {
+        candidate->second->setExtensions(num, extensions);
+    }
+}
+
 //
 // Make all symbols in this table level read only.
 //

glslang/MachineIndependent/SymbolTable.h

@@ -571,6 +571,7 @@ public:
 
     void relateToOperator(const char* name, TOperator op);
     void setFunctionExtensions(const char* name, int num, const char* const extensions[]);
+    void setSingleFunctionExtensions(const char* name, int num, const char* const extensions[]);
     void dump(TInfoSink& infoSink, bool complete = false) const;
     TSymbolTableLevel* clone() const;
     void readOnly();
@@ -872,6 +873,12 @@ public:
             table[level]->setFunctionExtensions(name, num, extensions);
     }
 
+    void setSingleFunctionExtensions(const char* name, int num, const char* const extensions[])
+    {
+        for (unsigned int level = 0; level < table.size(); ++level)
+            table[level]->setSingleFunctionExtensions(name, num, extensions);
+    }
+
     void setVariableExtensions(const char* name, int numExts, const char* const extensions[])
     {
         TSymbol* symbol = find(TString(name));

glslang/MachineIndependent/Versions.cpp

@@ -359,6 +359,7 @@ void TParseVersions::initializeExtensionBehavior()
     extensionBehavior[E_GL_EXT_opacity_micromap]            = EBhDisable;
     extensionBehavior[E_GL_EXT_ray_tracing_position_fetch]  = EBhDisable;
     extensionBehavior[E_GL_EXT_shader_tile_image]           = EBhDisable;
+    extensionBehavior[E_GL_EXT_texture_shadow_lod]          = EBhDisable;
 
     // OVR extensions
     extensionBehavior[E_GL_OVR_multiview]                = EBhDisable;

glslang/MachineIndependent/Versions.h

@@ -333,6 +333,8 @@ const char* const E_GL_EXT_shader_atomic_float2 = "GL_EXT_shader_atomic_float2";
 
 const char* const E_GL_EXT_shader_tile_image = "GL_EXT_shader_tile_image";
 
+const char* const E_GL_EXT_texture_shadow_lod = "GL_EXT_texture_shadow_lod";
+
 // Arrays of extensions for the above AEP duplications
 
 const char* const AEP_geometry_shader[] = { E_GL_EXT_geometry_shader, E_GL_OES_geometry_shader };

gtests/Spv.FromFile.cpp

@@ -526,6 +526,8 @@ INSTANTIATE_TEST_SUITE_P(
         "spv.atomicAdd.bufferReference.comp",
         "spv.fragmentShaderBarycentric3.frag",
         "spv.fragmentShaderBarycentric4.frag",
+        "spv.ext.texture_shadow_lod.frag",
+        "spv.ext.texture_shadow_lod.error.frag",
     })),
     FileNameAsCustomTestSuffix
 );