feat: add option to map unused uniforms

glslang/CInterface/glslang_c_interface.cpp

@@ -397,6 +397,10 @@ GLSLANG_EXPORT void glslang_shader_set_options(glslang_shader_t* shader, int opt
         shader->shader->setInvertY(true);
     }
 
+    if (options & GLSLANG_SHADER_MAP_UNUSED_UNIFORMS) {
+        shader->shader->setMapUnusedUniforms();
+    }
+    
 #ifdef ENABLE_HLSL
     if (options & GLSLANG_SHADER_HLSL_IO_MAPPING) {
         shader->shader->setHlslIoMapping(true);

glslang/Include/glslang_c_shader_types.h

@@ -212,9 +212,10 @@ typedef enum {
     GLSLANG_SHADER_AUTO_MAP_LOCATIONS = (1 << 1),
     GLSLANG_SHADER_VULKAN_RULES_RELAXED = (1 << 2),
     GLSLANG_SHADER_INVERT_Y = (1 << 3),
+    GLSLANG_SHADER_MAP_UNUSED_UNIFORMS = (1 << 4),
 #ifdef ENABLE_HLSL
-    GLSLANG_SHADER_HLSL_IO_MAPPING = (1 << 4),
+    GLSLANG_SHADER_HLSL_IO_MAPPING = (1 << 5),
-    GLSLANG_SHADER_HLSL_FLATTEN_UNIFORM_ARRAYS = (1 << 5),
+    GLSLANG_SHADER_HLSL_FLATTEN_UNIFORM_ARRAYS = (1 << 6),
 #endif
     LAST_ELEMENT_MARKER(GLSLANG_SHADER_COUNT),
 } glslang_shader_options_t;

glslang/MachineIndependent/ShaderLang.cpp

@@ -1843,6 +1843,8 @@ void TShader::setShiftUavBinding(unsigned int base)     { setShiftBinding(EResUa
 void TShader::setShiftSsboBinding(unsigned int base)    { setShiftBinding(EResSsbo, base); }
 // Enables binding automapping using TIoMapper
 void TShader::setAutoMapBindings(bool map)              { intermediate->setAutoMapBindings(map); }
+void TShader::setMapUnusedUniforms()                    { intermediate->setMapUnusedUniforms(); }
+
 // Enables position.Y output negation in vertex shader
 
 // Fragile: currently within one stage: simple auto-assignment of location

glslang/MachineIndependent/iomapper.cpp

@@ -885,6 +885,8 @@ bool TDefaultIoResolverBase::doAutoBindingMapping() const { return referenceInte
 
 bool TDefaultIoResolverBase::doAutoLocationMapping() const { return referenceIntermediate.getAutoMapLocations(); }
 
+bool TDefaultIoResolverBase::doMapUnusedUniforms() const { return referenceIntermediate.getMapUnusedUniforms(); }
+
 TDefaultIoResolverBase::TSlotSet::iterator TDefaultIoResolverBase::findSlot(int set, int slot) {
     return std::lower_bound(slots[set].begin(), slots[set].end(), slot);
 }
@@ -1230,7 +1232,7 @@ int TDefaultGlslIoResolver::resolveBinding(EShLanguage stage, TVarEntryInfo& ent
                     ent.newBinding = iter->second;
                 }
             }
-            if (!hasBinding && (ent.live && doAutoBindingMapping())) {
+            if (!hasBinding && ((ent.live || doMapUnusedUniforms()) && doAutoBindingMapping())) {
                 // find free slot, the caller did make sure it passes all vars with binding
                 // first and now all are passed that do not have a binding and needs one
                 int binding = getFreeSlot(resourceKey, getBaseBinding(stage, resource, set), numBindings);
@@ -1408,7 +1410,7 @@ struct TDefaultIoResolver : public TDefaultIoResolverBase {
             if (type.getQualifier().hasBinding()) {
                 return ent.newBinding = reserveSlot(
                            set, getBaseBinding(stage, resource, set) + type.getQualifier().layoutBinding, numBindings);
-            } else if (ent.live && doAutoBindingMapping()) {
+            } else if ((ent.live || doMapUnusedUniforms()) && doAutoBindingMapping()) {
                 // find free slot, the caller did make sure it passes all vars with binding
                 // first and now all are passed that do not have a binding and needs one
                 return ent.newBinding = getFreeSlot(set, getBaseBinding(stage, resource, set), numBindings);
@@ -1490,7 +1492,7 @@ struct TDefaultHlslIoResolver : public TDefaultIoResolverBase {
         if (resource < EResCount) {
             if (type.getQualifier().hasBinding()) {
                 return ent.newBinding = reserveSlot(set, getBaseBinding(stage, resource, set) + type.getQualifier().layoutBinding);
-            } else if (ent.live && doAutoBindingMapping()) {
+            } else if ((ent.live || doMapUnusedUniforms()) && doAutoBindingMapping()) {
                 // find free slot, the caller did make sure it passes all vars with binding
                 // first and now all are passed that do not have a binding and needs one
                 return ent.newBinding = getFreeSlot(set, getBaseBinding(stage, resource, set));

glslang/MachineIndependent/iomapper.h

@@ -72,6 +72,7 @@ public:
     virtual TResourceType getResourceType(const glslang::TType& type) = 0;
     bool doAutoBindingMapping() const;
     bool doAutoLocationMapping() const;
+    bool doMapUnusedUniforms() const;
     TSlotSet::iterator findSlot(int set, int slot);
     bool checkEmpty(int set, int slot);
     bool validateInOut(EShLanguage /*stage*/, TVarEntryInfo& /*ent*/) override { return true; }

glslang/MachineIndependent/localintermediate.h

@@ -344,6 +344,7 @@ public:
         numTaskEXTPayloads(0),
         autoMapBindings(false),
         autoMapLocations(false),
+        mapUnusedUniforms(false),
         flattenUniformArrays(false),
         useUnknownFormat(false),
         hlslOffsets(false),
@@ -1008,6 +1009,9 @@ public:
         else
             return pos->second;
     }
+
+    void setMapUnusedUniforms() { mapUnusedUniforms = true; }
+    bool getMapUnusedUniforms() const { return mapUnusedUniforms; }
 #ifdef ENABLE_HLSL
     void setHlslFunctionality1() { hlslFunctionality1 = true; }
     bool getHlslFunctionality1() const { return hlslFunctionality1; }
@@ -1237,6 +1241,7 @@ protected:
     std::vector<std::string> resourceSetBinding;
     bool autoMapBindings;
     bool autoMapLocations;
+    bool mapUnusedUniforms;
     bool flattenUniformArrays;
     bool useUnknownFormat;
     bool hlslOffsets;

glslang/Public/ShaderLang.h

@@ -491,6 +491,7 @@ public:
     GLSLANG_EXPORT void setResourceSetBinding(const std::vector<std::string>& base);
     GLSLANG_EXPORT void setAutoMapBindings(bool map);
     GLSLANG_EXPORT void setAutoMapLocations(bool map);
+    GLSLANG_EXPORT void setMapUnusedUniforms();
     GLSLANG_EXPORT void addUniformLocationOverride(const char* name, int loc);
     GLSLANG_EXPORT void setUniformLocationBase(int base);
     GLSLANG_EXPORT void setInvertY(bool invert);