Front-end infrastructure: Encapsulate semantic-level questions/actions about const/temp.

Much about const or temp is mechanical, about actual declaration,
while much is semantic, about something higher level.  This commit
checks every use everywhere, and for the high-level ones, substitutes
an encapsulated version instead.

SPIRV/GlslangToSpv.cpp

@@ -1629,7 +1629,7 @@ spv::Id TGlslangToSpvTraverser::createSpvVariable(const glslang::TIntermSymbol*
     // First, steer off constants, which are not SPIR-V variables, but 
     // can still have a mapping to a SPIR-V Id.
     // This includes specialization constants.
-    if (node->getQualifier().storage == glslang::EvqConst) {
+    if (node->getQualifier().isConstant()) {
         return createSpvSpecConstant(*node);
     }
 
@@ -3732,7 +3732,7 @@ void TGlslangToSpvTraverser::addMemberDecoration(spv::Id id, int member, spv::De
 //  - when running into a non-spec-constant, switch to createSpvConstant()
 spv::Id TGlslangToSpvTraverser::createSpvSpecConstant(const glslang::TIntermTyped& node)
 {
-    assert(node.getQualifier().storage == glslang::EvqConst);
+    assert(node.getQualifier().isConstant());
 
     if (! node.getQualifier().specConstant) {
         // hand off to the non-spec-constant path

Test/baseResults/310.comp.out

@@ -337,7 +337,7 @@ ERROR: node is still EOpNull!
 0:201              1 (const int)
 0:201          Constant:
 0:201            2 (const int)
-0:202      Test condition and select (layout(column_major shared ) temp highp float)
+0:202      Test condition and select (temp highp float)
 0:202        Condition
 0:202        'b' (temp bool)
 0:202        true case
@@ -764,7 +764,7 @@ ERROR: node is still EOpNull!
 0:201              1 (const int)
 0:201          Constant:
 0:201            2 (const int)
-0:202      Test condition and select (layout(column_major shared ) temp highp float)
+0:202      Test condition and select (temp highp float)
 0:202        Condition
 0:202        'b' (temp bool)
 0:202        true case

glslang/Include/Types.h

@@ -411,6 +411,19 @@ public:
         clearLayout();
     }
 
+    // Drop just the storage qualification, which perhaps should 
+    // never be done, as it is fundamentally inconsistent, but need to
+    // explore what downstream consumers need.
+    // E.g., in a deference, it is an inconsistency between:
+    // A) partially dereferenced resource is still in the storage class it started in
+    // B) partially dereferenced resource is a new temporary object
+    // If A, then nothing should change, if B, then everything should change, but this is half way.
+    void makePartialTemporary()
+    {
+        storage      = EvqTemporary;
+        specConstant = false;
+    }
+
     TStorageQualifier   storage   : 6;
     TBuiltInVariable    builtIn   : 8;
     TPrecisionQualifier precision : 3;

glslang/MachineIndependent/Intermediate.cpp

@@ -822,7 +822,7 @@ TIntermTyped* TIntermediate::addSelection(TIntermTyped* cond, TIntermTyped* true
     // Make a selection node.
     //
     TIntermSelection* node = new TIntermSelection(cond, trueBlock, falseBlock, trueBlock->getType());
-    node->getQualifier().storage = EvqTemporary;
+    node->getQualifier().makeTemporary();
     node->setLoc(loc);
     node->getQualifier().precision = std::max(trueBlock->getQualifier().precision, falseBlock->getQualifier().precision);
 

glslang/MachineIndependent/ParseHelper.cpp

@@ -484,7 +484,7 @@ TIntermTyped* TParseContext::handleBracketDereference(const TSourceLoc& loc, TIn
     TIntermTyped* result = nullptr;
 
     int indexValue = 0;
-    if (index->getQualifier().storage == EvqConst) {
+    if (index->getQualifier().isConstant()) {
         indexValue = index->getAsConstantUnion()->getConstArray()[0].getIConst();
         checkIndex(loc, base->getType(), indexValue);
     }
@@ -495,7 +495,7 @@ TIntermTyped* TParseContext::handleBracketDereference(const TSourceLoc& loc, TIn
             error(loc, " left of '[' is not of type array, matrix, or vector ", base->getAsSymbolNode()->getName().c_str(), "");
         else
             error(loc, " left of '[' is not of type array, matrix, or vector ", "expression", "");
-    } else if (base->getType().getQualifier().storage == EvqConst && index->getQualifier().storage == EvqConst)
+    } else if (base->getType().getQualifier().isFrontEndConstant() && index->getQualifier().isFrontEndConstant())
         return intermediate.foldDereference(base, indexValue, loc);
     else {
         // at least one of base and index is variable...
@@ -503,7 +503,7 @@ TIntermTyped* TParseContext::handleBracketDereference(const TSourceLoc& loc, TIn
         if (base->getAsSymbolNode() && isIoResizeArray(base->getType()))
             handleIoResizeArrayAccess(loc, base);
 
-        if (index->getQualifier().storage == EvqConst) {
+        if (index->getQualifier().isConstant()) {
             if (base->getType().isImplicitlySizedArray())
                 updateImplicitArraySize(loc, base, indexValue);
             result = intermediate.addIndex(EOpIndexDirect, base, index, loc);
@@ -541,10 +541,10 @@ TIntermTyped* TParseContext::handleBracketDereference(const TSourceLoc& loc, TIn
     } else {
         // Insert valid dereferenced result
         TType newType(base->getType(), 0);  // dereferenced type
-        if (base->getType().getQualifier().storage == EvqConst && index->getQualifier().storage == EvqConst)
+        if (base->getType().getQualifier().isFrontEndConstant() && index->getQualifier().isFrontEndConstant())
             newType.getQualifier().storage = EvqConst;
         else
-            newType.getQualifier().storage = EvqTemporary;
+            newType.getQualifier().makePartialTemporary();
         result->setType(newType);
 
         if (anyIndexLimits)
@@ -587,7 +587,7 @@ void TParseContext::handleIndexLimits(const TSourceLoc& /*loc*/, TIntermTyped* b
         (! limits.generalVariableIndexing && ! base->getType().getQualifier().isUniformOrBuffer() &&
                                              ! base->getType().getQualifier().isPipeInput() &&
                                              ! base->getType().getQualifier().isPipeOutput() &&
-                                               base->getType().getQualifier().storage != EvqConst) ||
+                                             ! base->getType().getQualifier().isConstant()) ||
         (! limits.generalVaryingIndexing && (base->getType().getQualifier().isPipeInput() ||
                                                 base->getType().getQualifier().isPipeOutput()))) {
         // it's too early to know what the inductive variables are, save it for post processing
@@ -849,7 +849,7 @@ TIntermTyped* TParseContext::handleDotDereference(const TSourceLoc& loc, TInterm
             }
         }
         if (fieldFound) {
-            if (base->getType().getQualifier().storage == EvqConst)
+            if (base->getType().getQualifier().isFrontEndConstant())
                 result = intermediate.foldDereference(base, member, loc);
             else {
                 blockMemberExtensionCheck(loc, base, field);
@@ -2039,7 +2039,7 @@ void TParseContext::rValueErrorCheck(const TSourceLoc& loc, const char* op, TInt
 //
 void TParseContext::constantValueCheck(TIntermTyped* node, const char* token)
 {
-    if (node->getQualifier().storage != EvqConst)
+    if (! node->getQualifier().isConstant())
         error(node->getLoc(), "constant expression required", token, "");
 }
 
@@ -2204,6 +2204,7 @@ bool TParseContext::constructorError(const TSourceLoc& loc, TIntermNode* node, T
 
     int size = 0;
     bool constType = true;
+    bool specConstType = true;
     bool full = false;
     bool overFull = false;
     bool matrixInMatrix = false;
@@ -2232,12 +2233,17 @@ bool TParseContext::constructorError(const TSourceLoc& loc, TIntermNode* node, T
         if (op != EOpConstructStruct && ! type.isArray() && size >= type.computeNumComponents())
             full = true;
 
-        if (function[arg].type->getQualifier().storage != EvqConst)
+        if (! function[arg].type->getQualifier().isConstant())
             constType = false;
+        if (! function[arg].type->getQualifier().isSpecConstant())
+            specConstType = false;
     }
 
-    if (constType)
+    if (constType) {
         type.getQualifier().storage = EvqConst;
+        if (specConstType)
+            type.getQualifier().specConstant = true;
+    }
 
     if (type.isArray()) {
         if (function.getParamCount() == 0) {
@@ -3147,7 +3153,7 @@ void TParseContext::nonInitConstCheck(const TSourceLoc& loc, TString& identifier
     //
     if (type.getQualifier().storage == EvqConst ||
         type.getQualifier().storage == EvqConstReadOnly) {
-        type.getQualifier().storage = EvqTemporary;
+        type.getQualifier().makeTemporary();
         error(loc, "variables with qualifier 'const' must be initialized", identifier.c_str(), "");
     }
 }
@@ -4848,7 +4854,7 @@ TIntermNode* TParseContext::executeInitializer(const TSourceLoc& loc, TIntermTyp
     if (! initializer) {
         // error recovery; don't leave const without constant values
         if (qualifier == EvqConst)
-            variable->getWritableType().getQualifier().storage = EvqTemporary;
+            variable->getWritableType().getQualifier().makeTemporary();
         return nullptr;
     }
 
@@ -4868,21 +4874,22 @@ TIntermNode* TParseContext::executeInitializer(const TSourceLoc& loc, TIntermTyp
         }
     }
 
-    // Uniform and global consts require a constant initializer
+    // Uniforms require a compile-time constant initializer
-    if (qualifier == EvqUniform && initializer->getType().getQualifier().storage != EvqConst) {
+    if (qualifier == EvqUniform && ! initializer->getType().getQualifier().isFrontEndConstant()) {
         error(loc, "uniform initializers must be constant", "=", "'%s'", variable->getType().getCompleteString().c_str());
-        variable->getWritableType().getQualifier().storage = EvqTemporary;
+        variable->getWritableType().getQualifier().makeTemporary();
         return nullptr;
     }
-    if (qualifier == EvqConst && symbolTable.atGlobalLevel() && initializer->getType().getQualifier().storage != EvqConst) {
+    // Global consts require a constant initializer (specialization constant is okay)
+    if (qualifier == EvqConst && symbolTable.atGlobalLevel() && ! initializer->getType().getQualifier().isConstant()) {
         error(loc, "global const initializers must be constant", "=", "'%s'", variable->getType().getCompleteString().c_str());
-        variable->getWritableType().getQualifier().storage = EvqTemporary;
+        variable->getWritableType().getQualifier().makeTemporary();
         return nullptr;
     }
 
     // Const variables require a constant initializer, depending on version
     if (qualifier == EvqConst) {
-        if (initializer->getType().getQualifier().storage != EvqConst) {
+        if (! initializer->getType().getQualifier().isConstant()) {
             const char* initFeature = "non-constant initializer";
             requireProfile(loc, ~EEsProfile, initFeature);
             profileRequires(loc, ~EEsProfile, 420, E_GL_ARB_shading_language_420pack, initFeature);
@@ -4894,7 +4901,7 @@ TIntermNode* TParseContext::executeInitializer(const TSourceLoc& loc, TIntermTyp
         //
         // "In declarations of global variables with no storage qualifier or with a const
         // qualifier any initializer must be a constant expression."
-        if (symbolTable.atGlobalLevel() && initializer->getType().getQualifier().storage != EvqConst) {
+        if (symbolTable.atGlobalLevel() && ! initializer->getType().getQualifier().isConstant()) {
             const char* initFeature = "non-constant global initializer";
             if (relaxedErrors())
                 warn(loc, "not allowed in this version", initFeature, "");
@@ -4910,7 +4917,7 @@ TIntermNode* TParseContext::executeInitializer(const TSourceLoc& loc, TIntermTyp
         if (! initializer || ! initializer->getAsConstantUnion() || variable->getType() != initializer->getType()) {
             error(loc, "non-matching or non-convertible constant type for const initializer",
                   variable->getType().getStorageQualifierString(), "");
-            variable->getWritableType().getQualifier().storage = EvqTemporary;
+            variable->getWritableType().getQualifier().makeTemporary();
             return nullptr;
         }