//
// Create loop nodes.
//
TIntermNode* TIntermediate::addLoop(TIntermNode* body, TIntermTyped* test, TIntermTyped* terminal, bool testFirst, TSourceLoc line)
{
TIntermNode* node = new TIntermLoop(body, test, terminal, testFirst);
node->setLine(line);
return node;
}
// Takes an expression like "f(x)" and creates a dependency graph like
// "x -> argument 0 -> function call".
void TDependencyGraphBuilder::visitFunctionCall(TIntermAggregate* intermFunctionCall)
{
TGraphFunctionCall* functionCall = mGraph->createFunctionCall(intermFunctionCall);
// Run through the function call arguments.
int argumentNumber = 0;
TIntermSequence& intermArguments = intermFunctionCall->getSequence();
for (TIntermSequence::const_iterator iter = intermArguments.begin();
iter != intermArguments.end();
++iter, ++argumentNumber)
{
TNodeSetMaintainer nodeSetMaintainer(this);
TIntermNode* intermArgument = *iter;
intermArgument->traverse(this);
if (TParentNodeSet* argumentNodes = mNodeSets.getTopSet()) {
TGraphArgument* argument = mGraph->createArgument(intermFunctionCall, argumentNumber);
connectMultipleNodesToSingleNode(argumentNodes, argument);
argument->addDependentNode(functionCall);
}
}
// Push the leftmost symbol of this function call into the current set of dependent symbols to
// represent the result of this function call.
// Thus, an expression like "y = f(x)" will yield a dependency graph like
// "x -> argument 0 -> function call -> y".
// This line essentially passes the function call node back up to an earlier visitAssignment
// call, which will create the connection "function call -> y".
mNodeSets.insertIntoTopSet(functionCall);
}
//
// Create loop nodes.
//
TIntermNode* TIntermediate::addLoop(TLoopType type, TIntermNode* init, TIntermTyped* cond, TIntermTyped* expr, TIntermNode* body, TSourceLoc line)
{
TIntermNode* node = new TIntermLoop(type, init, cond, expr, body);
node->setLine(line);
return node;
}
bool isChildofMain(TIntermNode *node, TIntermNode *root)
{
TIntermNode *main = getFunctionBySignature(MAIN_FUNC_SIGNATURE, root);
if (!main) {
dbgPrint(DBGLVL_ERROR, "CodeTools - could not find main function\n");
exit(1);
}
TIntermAggregate *aggregate;
if (!(aggregate = main->getAsAggregate())) {
dbgPrint(DBGLVL_ERROR, "CodeTools - main is not Aggregate\n");
exit(1);
}
TIntermSequence sequence = aggregate->getSequence();
TIntermSequence::iterator sit;
for(sit = sequence.begin(); sit != sequence.end(); sit++) {
if (*sit == node) {
return true;
}
}
return false;
}
// Map I/O variables to provided offsets, and make bindings for
// unbound but live variables.
//
// Returns false if the input is too malformed to do this.
bool TIoMapper::addStage(EShLanguage stage, TIntermediate &intermediate, TInfoSink &infoSink, TIoMapResolver *resolver)
{
// Trivial return if there is nothing to do.
if (intermediate.getShiftSamplerBinding() == 0 &&
intermediate.getShiftTextureBinding() == 0 &&
intermediate.getShiftImageBinding() == 0 &&
intermediate.getShiftUboBinding() == 0 &&
intermediate.getAutoMapBindings() == false &&
resolver == nullptr)
return true;
if (intermediate.getNumEntryPoints() != 1 || intermediate.isRecursive())
return false;
TIntermNode* root = intermediate.getTreeRoot();
if (root == nullptr)
return false;
// if no resolver is provided, use the default resolver with the given shifts and auto map settings
TDefaultIoResolver defaultResolver;
if (resolver == nullptr) {
defaultResolver.baseSamplerBinding = intermediate.getShiftSamplerBinding();
defaultResolver.baseTextureBinding = intermediate.getShiftTextureBinding();
defaultResolver.baseImageBinding = intermediate.getShiftImageBinding();
defaultResolver.baseUboBinding = intermediate.getShiftUboBinding();
defaultResolver.doAutoMapping = intermediate.getAutoMapBindings();
resolver = &defaultResolver;
}
TVarLiveMap varMap;
TVarGatherTraverser iter_binding_all(intermediate, varMap, true);
TVarGatherTraverser iter_binding_live(intermediate, varMap, false);
root->traverse(&iter_binding_all);
iter_binding_live.pushFunction(intermediate.getEntryPointMangledName().c_str());
while (!iter_binding_live.functions.empty()) {
TIntermNode* function = iter_binding_live.functions.back();
iter_binding_live.functions.pop_back();
function->traverse(&iter_binding_live);
}
// sort entries by priority. see TVarEntryInfo::TOrderByPriority for info.
std::sort(varMap.begin(), varMap.end(), TVarEntryInfo::TOrderByPriority());
bool hadError = false;
TResolverAdaptor doResolve(stage, *resolver, infoSink, hadError);
std::for_each(varMap.begin(), varMap.end(), doResolve);
if (!hadError) {
// sort by id again, so we can use lower bound to find entries
std::sort(varMap.begin(), varMap.end(), TVarEntryInfo::TOrderById());
TVarSetTraverser iter_iomap(intermediate, varMap);
root->traverse(&iter_iomap);
}
return !hadError;
}
bool ValidateLimitations::validateForLoopCond(TIntermLoop *node,
int indexSymbolId)
{
TIntermNode *cond = node->getCondition();
if (cond == NULL)
{
error(node->getLine(), "Missing condition", "for");
return false;
}
//
// condition has the form:
// loop_index relational_operator constant_expression
//
TIntermBinary *binOp = cond->getAsBinaryNode();
if (binOp == NULL)
{
error(node->getLine(), "Invalid condition", "for");
return false;
}
// Loop index should be to the left of relational operator.
TIntermSymbol *symbol = binOp->getLeft()->getAsSymbolNode();
if (symbol == NULL)
{
error(binOp->getLine(), "Invalid condition", "for");
return false;
}
if (symbol->getId() != indexSymbolId)
{
error(symbol->getLine(),
"Expected loop index", symbol->getSymbol().c_str());
return false;
}
// Relational operator is one of: > >= < <= == or !=.
switch (binOp->getOp())
{
case EOpEqual:
case EOpNotEqual:
case EOpLessThan:
case EOpGreaterThan:
case EOpLessThanEqual:
case EOpGreaterThanEqual:
break;
default:
error(binOp->getLine(),
"Invalid relational operator",
GetOperatorString(binOp->getOp()));
break;
}
// Loop index must be compared with a constant.
if (!isConstExpr(binOp->getRight()))
{
error(binOp->getLine(),
"Loop index cannot be compared with non-constant expression",
symbol->getSymbol().c_str());
return false;
}
return true;
}
int ValidateLimitations::validateForLoopInit(TIntermLoop *node)
{
TIntermNode *init = node->getInit();
if (init == NULL)
{
error(node->getLine(), "Missing init declaration", "for");
return -1;
}
//
// init-declaration has the form:
// type-specifier identifier = constant-expression
//
TIntermAggregate *decl = init->getAsAggregate();
if ((decl == NULL) || (decl->getOp() != EOpDeclaration))
{
error(init->getLine(), "Invalid init declaration", "for");
return -1;
}
// To keep things simple do not allow declaration list.
TIntermSequence &declSeq = decl->getSequence();
if (declSeq.size() != 1)
{
error(decl->getLine(), "Invalid init declaration", "for");
return -1;
}
TIntermBinary *declInit = declSeq[0]->getAsBinaryNode();
if ((declInit == NULL) || (declInit->getOp() != EOpInitialize))
{
error(decl->getLine(), "Invalid init declaration", "for");
return -1;
}
TIntermSymbol *symbol = declInit->getLeft()->getAsSymbolNode();
if (symbol == NULL)
{
error(declInit->getLine(), "Invalid init declaration", "for");
return -1;
}
// The loop index has type int or float.
TBasicType type = symbol->getBasicType();
if ((type != EbtInt) && (type != EbtFloat))
{
error(symbol->getLine(),
"Invalid type for loop index", getBasicString(type));
return -1;
}
// The loop index is initialized with constant expression.
if (!isConstExpr(declInit->getRight()))
{
error(declInit->getLine(),
"Loop index cannot be initialized with non-constant expression",
symbol->getSymbol().c_str());
return -1;
}
return symbol->getId();
}
void TDependencyGraphBuilder::visitAggregateChildren(TIntermAggregate* intermAggregate)
{
TIntermSequence& sequence = intermAggregate->getSequence();
for(TIntermSequence::const_iterator iter = sequence.begin(); iter != sequence.end(); ++iter)
{
TIntermNode* intermChild = *iter;
intermChild->traverse(this);
}
}
//
// Create loop nodes.
//
TIntermNode *TIntermediate::addLoop(
TLoopType type, TIntermNode *init, TIntermTyped *cond, TIntermTyped *expr,
TIntermNode *body, const TSourceLoc &line)
{
TIntermNode *node = new TIntermLoop(type, init, cond, expr, ensureSequence(body));
node->setLine(line);
return node;
}
int ForLoopUnroll::getLoopIncrement(TIntermLoop* node)
{
TIntermNode* expr = node->getExpression();
ASSERT(expr != NULL);
// for expression has one of the following forms:
// loop_index++
// loop_index--
// loop_index += constant_expression
// loop_index -= constant_expression
// ++loop_index
// --loop_index
// The last two forms are not specified in the spec, but I am assuming
// its an oversight.
TIntermUnary* unOp = expr->getAsUnaryNode();
TIntermBinary* binOp = unOp ? NULL : expr->getAsBinaryNode();
TOperator op = EOpNull;
TIntermConstantUnion* incrementNode = NULL;
if (unOp != NULL) {
op = unOp->getOp();
} else if (binOp != NULL) {
op = binOp->getOp();
ASSERT(binOp->getRight() != NULL);
incrementNode = binOp->getRight()->getAsConstantUnion();
ASSERT(incrementNode != NULL);
}
int increment = 0;
// The operator is one of: ++ -- += -=.
switch (op) {
case EOpPostIncrement:
case EOpPreIncrement:
ASSERT((unOp != NULL) && (binOp == NULL));
increment = 1;
break;
case EOpPostDecrement:
case EOpPreDecrement:
ASSERT((unOp != NULL) && (binOp == NULL));
increment = -1;
break;
case EOpAddAssign:
ASSERT((unOp == NULL) && (binOp != NULL));
increment = evaluateIntConstant(incrementNode);
break;
case EOpSubAssign:
ASSERT((unOp == NULL) && (binOp != NULL));
increment = - evaluateIntConstant(incrementNode);
break;
default:
ASSERT(false);
}
return increment;
}
size_t FindMainIndex(TIntermBlock *root)
{
const TIntermSequence &sequence = *root->getSequence();
for (size_t index = 0; index < sequence.size(); ++index)
{
TIntermNode *node = sequence[index];
TIntermFunctionDefinition *nodeFunction = node->getAsFunctionDefinition();
if (nodeFunction != nullptr && nodeFunction->getFunction()->isMain())
{
return index;
}
}
return std::numeric_limits<size_t>::max();
}
bool ScalarizeVecAndMatConstructorArgs::visitAggregate(Visit visit, TIntermAggregate *node)
{
if (visit == PreVisit)
{
switch (node->getOp())
{
case EOpSequence:
mSequenceStack.push_back(TIntermSequence());
{
for (TIntermSequence::const_iterator iter = node->getSequence()->begin();
iter != node->getSequence()->end(); ++iter)
{
TIntermNode *child = *iter;
ASSERT(child != NULL);
child->traverse(this);
mSequenceStack.back().push_back(child);
}
}
if (mSequenceStack.back().size() > node->getSequence()->size())
{
node->getSequence()->clear();
*(node->getSequence()) = mSequenceStack.back();
}
mSequenceStack.pop_back();
return false;
case EOpConstructVec2:
case EOpConstructVec3:
case EOpConstructVec4:
case EOpConstructBVec2:
case EOpConstructBVec3:
case EOpConstructBVec4:
case EOpConstructIVec2:
case EOpConstructIVec3:
case EOpConstructIVec4:
if (ContainsMatrixNode(*(node->getSequence())))
scalarizeArgs(node, false, true);
break;
case EOpConstructMat2:
case EOpConstructMat3:
case EOpConstructMat4:
if (ContainsVectorNode(*(node->getSequence())))
scalarizeArgs(node, true, false);
break;
default:
break;
}
}
return true;
}
bool ValidateLimitations::visitLoop(Visit, TIntermLoop *node)
{
if (!validateLoopType(node))
return false;
if (!validateForLoopHeader(node))
return false;
TIntermNode *body = node->getBody();
if (body != NULL)
{
mLoopStack.push(node);
body->traverse(this);
mLoopStack.pop();
}
// The loop is fully processed - no need to visit children.
return false;
}
// static
bool ValidateLimitations::IsLimitedForLoop(TIntermLoop *loop)
{
// The shader type doesn't matter in this case.
ValidateLimitations validate(GL_FRAGMENT_SHADER, nullptr);
validate.mValidateIndexing = false;
validate.mValidateInnerLoops = false;
if (!validate.validateLoopType(loop))
return false;
if (!validate.validateForLoopHeader(loop))
return false;
TIntermNode *body = loop->getBody();
if (body != nullptr)
{
validate.mLoopStack.push(loop);
body->traverse(&validate);
validate.mLoopStack.pop();
}
return (validate.mNumErrors == 0);
}
bool ValidateLimitations::visitLoop(Visit, TIntermLoop* node)
{
if (!validateLoopType(node))
return false;
TLoopInfo info;
memset(&info, 0, sizeof(TLoopInfo));
info.loop = node;
if (!validateForLoopHeader(node, &info))
return false;
TIntermNode* body = node->getBody();
if (body != NULL) {
mLoopStack.push_back(info);
body->traverse(this);
mLoopStack.pop_back();
}
// The loop is fully processed - no need to visit children.
return false;
}
bool RegenerateStructNames::visitAggregate(Visit, TIntermAggregate *aggregate)
{
ASSERT(aggregate);
switch (aggregate->getOp())
{
case EOpSequence:
++mScopeDepth;
{
TIntermSequence &sequence = *(aggregate->getSequence());
for (size_t ii = 0; ii < sequence.size(); ++ii)
{
TIntermNode *node = sequence[ii];
ASSERT(node != NULL);
node->traverse(this);
}
}
--mScopeDepth;
return false;
default:
return true;
}
}
void ForLoopUnroll::FillLoopIndexInfo(TIntermLoop* node, TLoopIndexInfo& info)
{
ASSERT(node->getType() == ELoopFor);
ASSERT(node->getUnrollFlag());
TIntermNode* init = node->getInit();
ASSERT(init != NULL);
TIntermAggregate* decl = init->getAsAggregate();
ASSERT((decl != NULL) && (decl->getOp() == EOpDeclaration));
TIntermSequence& declSeq = decl->getSequence();
ASSERT(declSeq.size() == 1);
TIntermBinary* declInit = declSeq[0]->getAsBinaryNode();
ASSERT((declInit != NULL) && (declInit->getOp() == EOpInitialize));
TIntermSymbol* symbol = declInit->getLeft()->getAsSymbolNode();
ASSERT(symbol != NULL);
ASSERT(symbol->getBasicType() == EbtInt);
info.id = symbol->getId();
ASSERT(declInit->getRight() != NULL);
TIntermConstantUnion* initNode = declInit->getRight()->getAsConstantUnion();
ASSERT(initNode != NULL);
info.initValue = evaluateIntConstant(initNode);
info.currentValue = info.initValue;
TIntermNode* cond = node->getCondition();
ASSERT(cond != NULL);
TIntermBinary* binOp = cond->getAsBinaryNode();
ASSERT(binOp != NULL);
ASSERT(binOp->getRight() != NULL);
ASSERT(binOp->getRight()->getAsConstantUnion() != NULL);
info.incrementValue = getLoopIncrement(node);
info.stopValue = evaluateIntConstant(
binOp->getRight()->getAsConstantUnion());
info.op = binOp->getOp();
}
bool ElseBlockRewriter::visitAggregate(Visit visit, TIntermAggregate *node)
{
switch (node->getOp())
{
case EOpSequence:
{
for (size_t statementIndex = 0; statementIndex != node->getSequence().size(); statementIndex++)
{
TIntermNode *statement = node->getSequence()[statementIndex];
TIntermSelection *selection = statement->getAsSelectionNode();
if (selection && selection->getFalseBlock() != NULL)
{
node->getSequence()[statementIndex] = rewriteSelection(selection);
delete selection;
}
}
}
break;
default: break;
}
return true;
}
TIntermNode *TCompiler::compileTreeImpl(const char *const shaderStrings[],
size_t numStrings,
const int compileOptions)
{
clearResults();
ASSERT(numStrings > 0);
ASSERT(GetGlobalPoolAllocator());
// Reset the extension behavior for each compilation unit.
ResetExtensionBehavior(extensionBehavior);
// First string is path of source file if flag is set. The actual source follows.
size_t firstSource = 0;
if (compileOptions & SH_SOURCE_PATH)
{
mSourcePath = shaderStrings[0];
++firstSource;
}
TIntermediate intermediate(infoSink);
TParseContext parseContext(symbolTable, extensionBehavior, intermediate, shaderType, shaderSpec,
compileOptions, true, infoSink, getResources());
parseContext.setFragmentPrecisionHighOnESSL1(fragmentPrecisionHigh);
SetGlobalParseContext(&parseContext);
// We preserve symbols at the built-in level from compile-to-compile.
// Start pushing the user-defined symbols at global level.
TScopedSymbolTableLevel scopedSymbolLevel(&symbolTable);
// Parse shader.
bool success =
(PaParseStrings(numStrings - firstSource, &shaderStrings[firstSource], nullptr, &parseContext) == 0) &&
(parseContext.getTreeRoot() != nullptr);
shaderVersion = parseContext.getShaderVersion();
if (success && MapSpecToShaderVersion(shaderSpec) < shaderVersion)
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "unsupported shader version";
success = false;
}
TIntermNode *root = nullptr;
if (success)
{
mPragma = parseContext.pragma();
if (mPragma.stdgl.invariantAll)
{
symbolTable.setGlobalInvariant();
}
root = parseContext.getTreeRoot();
root = intermediate.postProcess(root);
// Highp might have been auto-enabled based on shader version
fragmentPrecisionHigh = parseContext.getFragmentPrecisionHigh();
// Disallow expressions deemed too complex.
if (success && (compileOptions & SH_LIMIT_EXPRESSION_COMPLEXITY))
success = limitExpressionComplexity(root);
// Create the function DAG and check there is no recursion
if (success)
success = initCallDag(root);
if (success && (compileOptions & SH_LIMIT_CALL_STACK_DEPTH))
success = checkCallDepth();
// Checks which functions are used and if "main" exists
if (success)
{
functionMetadata.clear();
functionMetadata.resize(mCallDag.size());
success = tagUsedFunctions();
}
if (success && !(compileOptions & SH_DONT_PRUNE_UNUSED_FUNCTIONS))
success = pruneUnusedFunctions(root);
// Prune empty declarations to work around driver bugs and to keep declaration output simple.
if (success)
PruneEmptyDeclarations(root);
if (success && shaderVersion == 300 && shaderType == GL_FRAGMENT_SHADER)
success = validateOutputs(root);
if (success && shouldRunLoopAndIndexingValidation(compileOptions))
success = validateLimitations(root);
if (success && (compileOptions & SH_TIMING_RESTRICTIONS))
success = enforceTimingRestrictions(root, (compileOptions & SH_DEPENDENCY_GRAPH) != 0);
if (success && shaderSpec == SH_CSS_SHADERS_SPEC)
rewriteCSSShader(root);
// Unroll for-loop markup needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_INTEGER_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kIntegerIndex,
shouldRunLoopAndIndexingValidation(compileOptions));
root->traverse(&marker);
}
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_SAMPLER_ARRAY_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kSamplerArrayIndex,
shouldRunLoopAndIndexingValidation(compileOptions));
root->traverse(&marker);
if (marker.samplerArrayIndexIsFloatLoopIndex())
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "sampler array index is float loop index";
success = false;
}
}
// Built-in function emulation needs to happen after validateLimitations pass.
if (success)
{
initBuiltInFunctionEmulator(&builtInFunctionEmulator, compileOptions);
builtInFunctionEmulator.MarkBuiltInFunctionsForEmulation(root);
}
// Clamping uniform array bounds needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_CLAMP_INDIRECT_ARRAY_BOUNDS))
arrayBoundsClamper.MarkIndirectArrayBoundsForClamping(root);
// gl_Position is always written in compatibility output mode
if (success && shaderType == GL_VERTEX_SHADER &&
((compileOptions & SH_INIT_GL_POSITION) ||
(outputType == SH_GLSL_COMPATIBILITY_OUTPUT)))
initializeGLPosition(root);
// This pass might emit short circuits so keep it before the short circuit unfolding
if (success && (compileOptions & SH_REWRITE_DO_WHILE_LOOPS))
RewriteDoWhile(root, getTemporaryIndex());
if (success && (compileOptions & SH_UNFOLD_SHORT_CIRCUIT))
{
UnfoldShortCircuitAST unfoldShortCircuit;
root->traverse(&unfoldShortCircuit);
unfoldShortCircuit.updateTree();
}
if (success && (compileOptions & SH_REMOVE_POW_WITH_CONSTANT_EXPONENT))
{
RemovePow(root);
}
if (success && shouldCollectVariables(compileOptions))
{
collectVariables(root);
if (compileOptions & SH_ENFORCE_PACKING_RESTRICTIONS)
{
success = enforcePackingRestrictions();
if (!success)
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "too many uniforms";
}
}
if (success && shaderType == GL_VERTEX_SHADER &&
(compileOptions & SH_INIT_VARYINGS_WITHOUT_STATIC_USE))
initializeVaryingsWithoutStaticUse(root);
}
if (success && (compileOptions & SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS))
{
ScalarizeVecAndMatConstructorArgs scalarizer(
shaderType, fragmentPrecisionHigh);
root->traverse(&scalarizer);
}
if (success && (compileOptions & SH_REGENERATE_STRUCT_NAMES))
{
RegenerateStructNames gen(symbolTable, shaderVersion);
root->traverse(&gen);
}
}
SetGlobalParseContext(NULL);
if (success)
return root;
return NULL;
}
// Create loop nodes
TIntermNode* ir_add_loop(TLoopType type, TIntermTyped* cond, TIntermTyped* expr, TIntermNode* body, TSourceLoc line)
{
TIntermNode* node = new TIntermLoop(type, cond, expr, body);
node->setLine(line);
return node;
}
bool TOutputGLSLBase::visitAggregate(Visit visit, TIntermAggregate *node)
{
bool visitChildren = true;
TInfoSinkBase &out = objSink();
bool useEmulatedFunction = (visit == PreVisit && node->getUseEmulatedFunction());
switch (node->getOp())
{
case EOpSequence:
// Scope the sequences except when at the global scope.
if (mDepth > 0)
{
out << "{\n";
}
incrementDepth(node);
for (TIntermSequence::const_iterator iter = node->getSequence()->begin();
iter != node->getSequence()->end(); ++iter)
{
TIntermNode *curNode = *iter;
ASSERT(curNode != NULL);
curNode->traverse(this);
if (isSingleStatement(curNode))
out << ";\n";
}
decrementDepth();
// Scope the sequences except when at the global scope.
if (mDepth > 0)
{
out << "}\n";
}
visitChildren = false;
break;
case EOpPrototype:
// Function declaration.
ASSERT(visit == PreVisit);
{
const TType &type = node->getType();
writeVariableType(type);
if (type.isArray())
out << arrayBrackets(type);
}
out << " " << hashFunctionNameIfNeeded(node->getNameObj());
out << "(";
writeFunctionParameters(*(node->getSequence()));
out << ")";
visitChildren = false;
break;
case EOpFunction: {
// Function definition.
ASSERT(visit == PreVisit);
{
const TType &type = node->getType();
writeVariableType(type);
if (type.isArray())
out << arrayBrackets(type);
}
out << " " << hashFunctionNameIfNeeded(node->getNameObj());
incrementDepth(node);
// Function definition node contains one or two children nodes
// representing function parameters and function body. The latter
// is not present in case of empty function bodies.
const TIntermSequence &sequence = *(node->getSequence());
ASSERT((sequence.size() == 1) || (sequence.size() == 2));
TIntermSequence::const_iterator seqIter = sequence.begin();
// Traverse function parameters.
TIntermAggregate *params = (*seqIter)->getAsAggregate();
ASSERT(params != NULL);
ASSERT(params->getOp() == EOpParameters);
params->traverse(this);
// Traverse function body.
TIntermAggregate *body = ++seqIter != sequence.end() ?
(*seqIter)->getAsAggregate() : NULL;
visitCodeBlock(body);
decrementDepth();
// Fully processed; no need to visit children.
visitChildren = false;
break;
}
case EOpFunctionCall:
// Function call.
if (visit == PreVisit)
out << hashFunctionNameIfNeeded(node->getNameObj()) << "(";
else if (visit == InVisit)
out << ", ";
else
out << ")";
break;
case EOpParameters:
// Function parameters.
ASSERT(visit == PreVisit);
out << "(";
writeFunctionParameters(*(node->getSequence()));
out << ")";
visitChildren = false;
break;
case EOpDeclaration:
// Variable declaration.
if (visit == PreVisit)
{
const TIntermSequence &sequence = *(node->getSequence());
const TIntermTyped *variable = sequence.front()->getAsTyped();
writeVariableType(variable->getType());
out << " ";
mDeclaringVariables = true;
}
else if (visit == InVisit)
{
out << ", ";
mDeclaringVariables = true;
}
else
{
mDeclaringVariables = false;
}
break;
case EOpInvariantDeclaration:
// Invariant declaration.
ASSERT(visit == PreVisit);
{
const TIntermSequence *sequence = node->getSequence();
ASSERT(sequence && sequence->size() == 1);
const TIntermSymbol *symbol = sequence->front()->getAsSymbolNode();
ASSERT(symbol);
out << "invariant " << hashVariableName(symbol->getSymbol());
}
visitChildren = false;
break;
case EOpConstructFloat:
writeConstructorTriplet(visit, node->getType(), "float");
break;
case EOpConstructVec2:
writeConstructorTriplet(visit, node->getType(), "vec2");
break;
case EOpConstructVec3:
writeConstructorTriplet(visit, node->getType(), "vec3");
break;
case EOpConstructVec4:
writeConstructorTriplet(visit, node->getType(), "vec4");
break;
case EOpConstructBool:
writeConstructorTriplet(visit, node->getType(), "bool");
break;
case EOpConstructBVec2:
writeConstructorTriplet(visit, node->getType(), "bvec2");
break;
case EOpConstructBVec3:
writeConstructorTriplet(visit, node->getType(), "bvec3");
break;
case EOpConstructBVec4:
writeConstructorTriplet(visit, node->getType(), "bvec4");
break;
case EOpConstructInt:
writeConstructorTriplet(visit, node->getType(), "int");
break;
case EOpConstructIVec2:
writeConstructorTriplet(visit, node->getType(), "ivec2");
break;
case EOpConstructIVec3:
writeConstructorTriplet(visit, node->getType(), "ivec3");
break;
case EOpConstructIVec4:
writeConstructorTriplet(visit, node->getType(), "ivec4");
break;
case EOpConstructUInt:
writeConstructorTriplet(visit, node->getType(), "uint");
break;
case EOpConstructUVec2:
writeConstructorTriplet(visit, node->getType(), "uvec2");
break;
case EOpConstructUVec3:
writeConstructorTriplet(visit, node->getType(), "uvec3");
break;
case EOpConstructUVec4:
writeConstructorTriplet(visit, node->getType(), "uvec4");
break;
case EOpConstructMat2:
writeConstructorTriplet(visit, node->getType(), "mat2");
break;
case EOpConstructMat2x3:
writeConstructorTriplet(visit, node->getType(), "mat2x3");
break;
case EOpConstructMat2x4:
writeConstructorTriplet(visit, node->getType(), "mat2x4");
break;
case EOpConstructMat3x2:
writeConstructorTriplet(visit, node->getType(), "mat3x2");
break;
case EOpConstructMat3:
writeConstructorTriplet(visit, node->getType(), "mat3");
break;
case EOpConstructMat3x4:
writeConstructorTriplet(visit, node->getType(), "mat3x4");
break;
case EOpConstructMat4x2:
writeConstructorTriplet(visit, node->getType(), "mat4x2");
break;
case EOpConstructMat4x3:
writeConstructorTriplet(visit, node->getType(), "mat4x3");
break;
case EOpConstructMat4:
writeConstructorTriplet(visit, node->getType(), "mat4");
break;
case EOpConstructStruct:
{
const TType &type = node->getType();
ASSERT(type.getBasicType() == EbtStruct);
TString constructorName = hashName(type.getStruct()->name());
writeConstructorTriplet(visit, node->getType(), constructorName.c_str());
break;
}
case EOpOuterProduct:
writeBuiltInFunctionTriplet(visit, "outerProduct(", useEmulatedFunction);
break;
case EOpLessThan:
writeBuiltInFunctionTriplet(visit, "lessThan(", useEmulatedFunction);
break;
case EOpGreaterThan:
writeBuiltInFunctionTriplet(visit, "greaterThan(", useEmulatedFunction);
break;
case EOpLessThanEqual:
writeBuiltInFunctionTriplet(visit, "lessThanEqual(", useEmulatedFunction);
break;
case EOpGreaterThanEqual:
writeBuiltInFunctionTriplet(visit, "greaterThanEqual(", useEmulatedFunction);
break;
case EOpVectorEqual:
writeBuiltInFunctionTriplet(visit, "equal(", useEmulatedFunction);
break;
case EOpVectorNotEqual:
writeBuiltInFunctionTriplet(visit, "notEqual(", useEmulatedFunction);
break;
case EOpComma:
writeTriplet(visit, "(", ", ", ")");
break;
case EOpMod:
writeBuiltInFunctionTriplet(visit, "mod(", useEmulatedFunction);
break;
case EOpModf:
writeBuiltInFunctionTriplet(visit, "modf(", useEmulatedFunction);
break;
case EOpPow:
writeBuiltInFunctionTriplet(visit, "pow(", useEmulatedFunction);
break;
case EOpAtan:
writeBuiltInFunctionTriplet(visit, "atan(", useEmulatedFunction);
break;
case EOpMin:
writeBuiltInFunctionTriplet(visit, "min(", useEmulatedFunction);
break;
case EOpMax:
writeBuiltInFunctionTriplet(visit, "max(", useEmulatedFunction);
break;
case EOpClamp:
writeBuiltInFunctionTriplet(visit, "clamp(", useEmulatedFunction);
break;
case EOpMix:
writeBuiltInFunctionTriplet(visit, "mix(", useEmulatedFunction);
break;
case EOpStep:
writeBuiltInFunctionTriplet(visit, "step(", useEmulatedFunction);
break;
case EOpSmoothStep:
writeBuiltInFunctionTriplet(visit, "smoothstep(", useEmulatedFunction);
break;
case EOpDistance:
writeBuiltInFunctionTriplet(visit, "distance(", useEmulatedFunction);
break;
case EOpDot:
writeBuiltInFunctionTriplet(visit, "dot(", useEmulatedFunction);
break;
case EOpCross:
writeBuiltInFunctionTriplet(visit, "cross(", useEmulatedFunction);
break;
case EOpFaceForward:
writeBuiltInFunctionTriplet(visit, "faceforward(", useEmulatedFunction);
break;
case EOpReflect:
writeBuiltInFunctionTriplet(visit, "reflect(", useEmulatedFunction);
break;
case EOpRefract:
writeBuiltInFunctionTriplet(visit, "refract(", useEmulatedFunction);
break;
case EOpMul:
writeBuiltInFunctionTriplet(visit, "matrixCompMult(", useEmulatedFunction);
break;
default:
UNREACHABLE();
}
return visitChildren;
}
bool TCompiler::compile(const char* const shaderStrings[],
size_t numStrings,
int compileOptions)
{
TScopedPoolAllocator scopedAlloc(&allocator);
clearResults();
if (numStrings == 0)
return true;
// If compiling for WebGL, validate loop and indexing as well.
if (IsWebGLBasedSpec(shaderSpec))
compileOptions |= SH_VALIDATE_LOOP_INDEXING;
// First string is path of source file if flag is set. The actual source follows.
const char* sourcePath = NULL;
size_t firstSource = 0;
if (compileOptions & SH_SOURCE_PATH)
{
sourcePath = shaderStrings[0];
++firstSource;
}
TIntermediate intermediate(infoSink);
TParseContext parseContext(symbolTable, extensionBehavior, intermediate,
shaderType, shaderSpec, compileOptions, true,
sourcePath, infoSink);
parseContext.fragmentPrecisionHigh = fragmentPrecisionHigh;
SetGlobalParseContext(&parseContext);
// We preserve symbols at the built-in level from compile-to-compile.
// Start pushing the user-defined symbols at global level.
TScopedSymbolTableLevel scopedSymbolLevel(&symbolTable);
// Parse shader.
bool success =
(PaParseStrings(numStrings - firstSource, &shaderStrings[firstSource], NULL, &parseContext) == 0) &&
(parseContext.treeRoot != NULL);
shaderVersion = parseContext.getShaderVersion();
if (success)
{
TIntermNode* root = parseContext.treeRoot;
success = intermediate.postProcess(root);
// Disallow expressions deemed too complex.
if (success && (compileOptions & SH_LIMIT_EXPRESSION_COMPLEXITY))
success = limitExpressionComplexity(root);
if (success)
success = detectCallDepth(root, infoSink, (compileOptions & SH_LIMIT_CALL_STACK_DEPTH) != 0);
if (success && shaderVersion == 300 && shaderType == GL_FRAGMENT_SHADER)
success = validateOutputs(root);
if (success && (compileOptions & SH_VALIDATE_LOOP_INDEXING))
success = validateLimitations(root);
if (success && (compileOptions & SH_TIMING_RESTRICTIONS))
success = enforceTimingRestrictions(root, (compileOptions & SH_DEPENDENCY_GRAPH) != 0);
if (success && shaderSpec == SH_CSS_SHADERS_SPEC)
rewriteCSSShader(root);
// Unroll for-loop markup needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_INTEGER_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kIntegerIndex);
root->traverse(&marker);
}
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_SAMPLER_ARRAY_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kSamplerArrayIndex);
root->traverse(&marker);
if (marker.samplerArrayIndexIsFloatLoopIndex())
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "sampler array index is float loop index";
success = false;
}
}
// Built-in function emulation needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_EMULATE_BUILT_IN_FUNCTIONS))
builtInFunctionEmulator.MarkBuiltInFunctionsForEmulation(root);
// Clamping uniform array bounds needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_CLAMP_INDIRECT_ARRAY_BOUNDS))
arrayBoundsClamper.MarkIndirectArrayBoundsForClamping(root);
if (success && shaderType == GL_VERTEX_SHADER && (compileOptions & SH_INIT_GL_POSITION))
initializeGLPosition(root);
if (success && (compileOptions & SH_UNFOLD_SHORT_CIRCUIT))
{
UnfoldShortCircuitAST unfoldShortCircuit;
root->traverse(&unfoldShortCircuit);
unfoldShortCircuit.updateTree();
}
if (success && (compileOptions & SH_VARIABLES))
{
collectVariables(root);
if (compileOptions & SH_ENFORCE_PACKING_RESTRICTIONS)
{
success = enforcePackingRestrictions();
if (!success)
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "too many uniforms";
}
}
if (success && shaderType == GL_VERTEX_SHADER &&
(compileOptions & SH_INIT_VARYINGS_WITHOUT_STATIC_USE))
initializeVaryingsWithoutStaticUse(root);
}
if (success && (compileOptions & SH_INTERMEDIATE_TREE))
intermediate.outputTree(root);
if (success && (compileOptions & SH_OBJECT_CODE))
translate(root);
}
// Cleanup memory.
intermediate.remove(parseContext.treeRoot);
SetGlobalParseContext(NULL);
return success;
}
TIntermNode *TCompiler::compileTreeImpl(const char* const shaderStrings[],
size_t numStrings, int compileOptions)
{
clearResults();
ASSERT(numStrings > 0);
ASSERT(GetGlobalPoolAllocator());
// Reset the extension behavior for each compilation unit.
ResetExtensionBehavior(extensionBehavior);
// If compiling for WebGL, validate loop and indexing as well.
if (IsWebGLBasedSpec(shaderSpec))
compileOptions |= SH_VALIDATE_LOOP_INDEXING;
// First string is path of source file if flag is set. The actual source follows.
size_t firstSource = 0;
if (compileOptions & SH_SOURCE_PATH)
{
mSourcePath = shaderStrings[0];
++firstSource;
}
bool debugShaderPrecision = getResources().WEBGL_debug_shader_precision == 1;
TIntermediate intermediate(infoSink);
TParseContext parseContext(symbolTable, extensionBehavior, intermediate,
shaderType, shaderSpec, compileOptions, true,
infoSink, debugShaderPrecision);
parseContext.fragmentPrecisionHigh = fragmentPrecisionHigh;
SetGlobalParseContext(&parseContext);
// We preserve symbols at the built-in level from compile-to-compile.
// Start pushing the user-defined symbols at global level.
TScopedSymbolTableLevel scopedSymbolLevel(&symbolTable);
// Parse shader.
bool success =
(PaParseStrings(numStrings - firstSource, &shaderStrings[firstSource], NULL, &parseContext) == 0) &&
(parseContext.treeRoot != NULL);
shaderVersion = parseContext.getShaderVersion();
if (success && MapSpecToShaderVersion(shaderSpec) < shaderVersion)
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "unsupported shader version";
success = false;
}
TIntermNode *root = NULL;
if (success)
{
mPragma = parseContext.pragma();
if (mPragma.stdgl.invariantAll)
{
symbolTable.setGlobalInvariant();
}
root = parseContext.treeRoot;
success = intermediate.postProcess(root);
// Disallow expressions deemed too complex.
if (success && (compileOptions & SH_LIMIT_EXPRESSION_COMPLEXITY))
success = limitExpressionComplexity(root);
if (success)
success = detectCallDepth(root, infoSink, (compileOptions & SH_LIMIT_CALL_STACK_DEPTH) != 0);
if (success && shaderVersion == 300 && shaderType == GL_FRAGMENT_SHADER)
success = validateOutputs(root);
if (success && (compileOptions & SH_VALIDATE_LOOP_INDEXING))
success = validateLimitations(root);
if (success && (compileOptions & SH_TIMING_RESTRICTIONS))
success = enforceTimingRestrictions(root, (compileOptions & SH_DEPENDENCY_GRAPH) != 0);
if (success && shaderSpec == SH_CSS_SHADERS_SPEC)
rewriteCSSShader(root);
// Unroll for-loop markup needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_INTEGER_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kIntegerIndex);
root->traverse(&marker);
}
if (success && (compileOptions & SH_UNROLL_FOR_LOOP_WITH_SAMPLER_ARRAY_INDEX))
{
ForLoopUnrollMarker marker(ForLoopUnrollMarker::kSamplerArrayIndex);
root->traverse(&marker);
if (marker.samplerArrayIndexIsFloatLoopIndex())
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "sampler array index is float loop index";
success = false;
}
}
// Built-in function emulation needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_EMULATE_BUILT_IN_FUNCTIONS))
builtInFunctionEmulator.MarkBuiltInFunctionsForEmulation(root);
// Clamping uniform array bounds needs to happen after validateLimitations pass.
if (success && (compileOptions & SH_CLAMP_INDIRECT_ARRAY_BOUNDS))
arrayBoundsClamper.MarkIndirectArrayBoundsForClamping(root);
if (success && shaderType == GL_VERTEX_SHADER && (compileOptions & SH_INIT_GL_POSITION))
initializeGLPosition(root);
if (success && (compileOptions & SH_UNFOLD_SHORT_CIRCUIT))
{
UnfoldShortCircuitAST unfoldShortCircuit;
root->traverse(&unfoldShortCircuit);
unfoldShortCircuit.updateTree();
}
if (success && (compileOptions & SH_VARIABLES))
{
collectVariables(root);
if (compileOptions & SH_ENFORCE_PACKING_RESTRICTIONS)
{
success = enforcePackingRestrictions();
if (!success)
{
infoSink.info.prefix(EPrefixError);
infoSink.info << "too many uniforms";
}
}
if (success && shaderType == GL_VERTEX_SHADER &&
(compileOptions & SH_INIT_VARYINGS_WITHOUT_STATIC_USE))
initializeVaryingsWithoutStaticUse(root);
}
if (success && (compileOptions & SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS))
{
ScalarizeVecAndMatConstructorArgs scalarizer(
shaderType, fragmentPrecisionHigh);
root->traverse(&scalarizer);
}
if (success && (compileOptions & SH_REGENERATE_STRUCT_NAMES))
{
RegenerateStructNames gen(symbolTable, shaderVersion);
root->traverse(&gen);
}
}
SetGlobalParseContext(NULL);
if (success)
return root;
return NULL;
}
bool TOutputGLSLBase::visitAggregate(Visit visit, TIntermAggregate* node)
{
bool visitChildren = true;
TInfoSinkBase& out = objSink();
TString preString;
bool delayedWrite = false;
switch (node->getOp())
{
case EOpSequence: {
// Scope the sequences except when at the global scope.
if (depth > 0) out << "{\n";
incrementDepth();
const TIntermSequence& sequence = node->getSequence();
for (TIntermSequence::const_iterator iter = sequence.begin();
iter != sequence.end(); ++iter)
{
TIntermNode* node = *iter;
ASSERT(node != NULL);
node->traverse(this);
if (isSingleStatement(node))
out << ";\n";
}
decrementDepth();
// Scope the sequences except when at the global scope.
if (depth > 0) out << "}\n";
visitChildren = false;
break;
}
case EOpPrototype: {
// Function declaration.
ASSERT(visit == PreVisit);
writeVariableType(node->getType());
out << " " << node->getName();
out << "(";
writeFunctionParameters(node->getSequence());
out << ")";
visitChildren = false;
break;
}
case EOpFunction: {
// Function definition.
ASSERT(visit == PreVisit);
writeVariableType(node->getType());
out << " " << TFunction::unmangleName(node->getName());
incrementDepth();
// Function definition node contains one or two children nodes
// representing function parameters and function body. The latter
// is not present in case of empty function bodies.
const TIntermSequence& sequence = node->getSequence();
ASSERT((sequence.size() == 1) || (sequence.size() == 2));
TIntermSequence::const_iterator seqIter = sequence.begin();
// Traverse function parameters.
TIntermAggregate* params = (*seqIter)->getAsAggregate();
ASSERT(params != NULL);
ASSERT(params->getOp() == EOpParameters);
params->traverse(this);
// Traverse function body.
TIntermAggregate* body = ++seqIter != sequence.end() ?
(*seqIter)->getAsAggregate() : NULL;
visitCodeBlock(body);
decrementDepth();
// Fully processed; no need to visit children.
visitChildren = false;
break;
}
case EOpFunctionCall:
// Function call.
if (visit == PreVisit)
{
TString functionName = TFunction::unmangleName(node->getName());
out << functionName << "(";
}
else if (visit == InVisit)
{
out << ", ";
}
else
{
out << ")";
}
break;
case EOpParameters: {
// Function parameters.
ASSERT(visit == PreVisit);
out << "(";
writeFunctionParameters(node->getSequence());
out << ")";
visitChildren = false;
break;
}
case EOpDeclaration: {
// Variable declaration.
if (visit == PreVisit)
{
const TIntermSequence& sequence = node->getSequence();
const TIntermTyped* variable = sequence.front()->getAsTyped();
writeVariableType(variable->getType());
out << " ";
mDeclaringVariables = true;
}
else if (visit == InVisit)
{
out << ", ";
mDeclaringVariables = true;
}
else
{
mDeclaringVariables = false;
}
break;
}
case EOpConstructFloat: writeTriplet(visit, "float(", NULL, ")"); break;
case EOpConstructVec2: writeTriplet(visit, "vec2(", ", ", ")"); break;
case EOpConstructVec3: writeTriplet(visit, "vec3(", ", ", ")"); break;
case EOpConstructVec4: writeTriplet(visit, "vec4(", ", ", ")"); break;
case EOpConstructBool: writeTriplet(visit, "bool(", NULL, ")"); break;
case EOpConstructBVec2: writeTriplet(visit, "bvec2(", ", ", ")"); break;
case EOpConstructBVec3: writeTriplet(visit, "bvec3(", ", ", ")"); break;
case EOpConstructBVec4: writeTriplet(visit, "bvec4(", ", ", ")"); break;
case EOpConstructInt: writeTriplet(visit, "int(", NULL, ")"); break;
case EOpConstructIVec2: writeTriplet(visit, "ivec2(", ", ", ")"); break;
case EOpConstructIVec3: writeTriplet(visit, "ivec3(", ", ", ")"); break;
case EOpConstructIVec4: writeTriplet(visit, "ivec4(", ", ", ")"); break;
case EOpConstructMat2: writeTriplet(visit, "mat2(", ", ", ")"); break;
case EOpConstructMat3: writeTriplet(visit, "mat3(", ", ", ")"); break;
case EOpConstructMat4: writeTriplet(visit, "mat4(", ", ", ")"); break;
case EOpConstructStruct:
if (visit == PreVisit)
{
const TType& type = node->getType();
ASSERT(type.getBasicType() == EbtStruct);
out << type.getTypeName() << "(";
}
else if (visit == InVisit)
{
out << ", ";
}
else
{
out << ")";
}
break;
case EOpLessThan: preString = "lessThan("; delayedWrite = true; break;
case EOpGreaterThan: preString = "greaterThan("; delayedWrite = true; break;
case EOpLessThanEqual: preString = "lessThanEqual("; delayedWrite = true; break;
case EOpGreaterThanEqual: preString = "greaterThanEqual("; delayedWrite = true; break;
case EOpVectorEqual: preString = "equal("; delayedWrite = true; break;
case EOpVectorNotEqual: preString = "notEqual("; delayedWrite = true; break;
case EOpComma: writeTriplet(visit, NULL, ", ", NULL); break;
case EOpMod: preString = "mod("; delayedWrite = true; break;
case EOpPow: preString = "pow("; delayedWrite = true; break;
case EOpAtan: preString = "atan("; delayedWrite = true; break;
case EOpMin: preString = "min("; delayedWrite = true; break;
case EOpMax: preString = "max("; delayedWrite = true; break;
case EOpClamp: preString = "clamp("; delayedWrite = true; break;
case EOpMix: preString = "mix("; delayedWrite = true; break;
case EOpStep: preString = "step("; delayedWrite = true; break;
case EOpSmoothStep: preString = "smoothstep("; delayedWrite = true; break;
case EOpDistance: preString = "distance("; delayedWrite = true; break;
case EOpDot: preString = "dot("; delayedWrite = true; break;
case EOpCross: preString = "cross("; delayedWrite = true; break;
case EOpFaceForward: preString = "faceforward("; delayedWrite = true; break;
case EOpReflect: preString = "reflect("; delayedWrite = true; break;
case EOpRefract: preString = "refract("; delayedWrite = true; break;
case EOpMul: preString = "matrixCompMult("; delayedWrite = true; break;
default: UNREACHABLE(); break;
}
if (delayedWrite && visit == PreVisit && node->getUseEmulatedFunction())
preString = BuiltInFunctionEmulator::GetEmulatedFunctionName(preString);
if (delayedWrite)
writeTriplet(visit, preString.c_str(), ", ", ")");
return visitChildren;
}
bool ValidateLimitations::validateForLoopExpr(TIntermLoop *node,
int indexSymbolId)
{
TIntermNode *expr = node->getExpression();
if (expr == NULL)
{
error(node->getLine(), "Missing expression", "for");
return false;
}
// for expression has one of the following forms:
// loop_index++
// loop_index--
// loop_index += constant_expression
// loop_index -= constant_expression
// ++loop_index
// --loop_index
// The last two forms are not specified in the spec, but I am assuming
// its an oversight.
TIntermUnary *unOp = expr->getAsUnaryNode();
TIntermBinary *binOp = unOp ? NULL : expr->getAsBinaryNode();
TOperator op = EOpNull;
TIntermSymbol *symbol = NULL;
if (unOp != NULL)
{
op = unOp->getOp();
symbol = unOp->getOperand()->getAsSymbolNode();
}
else if (binOp != NULL)
{
op = binOp->getOp();
symbol = binOp->getLeft()->getAsSymbolNode();
}
// The operand must be loop index.
if (symbol == NULL)
{
error(expr->getLine(), "Invalid expression", "for");
return false;
}
if (symbol->getId() != indexSymbolId)
{
error(symbol->getLine(),
"Expected loop index", symbol->getSymbol().c_str());
return false;
}
// The operator is one of: ++ -- += -=.
switch (op)
{
case EOpPostIncrement:
case EOpPostDecrement:
case EOpPreIncrement:
case EOpPreDecrement:
ASSERT((unOp != NULL) && (binOp == NULL));
break;
case EOpAddAssign:
case EOpSubAssign:
ASSERT((unOp == NULL) && (binOp != NULL));
break;
default:
error(expr->getLine(), "Invalid operator", GetOperatorString(op));
return false;
}
// Loop index must be incremented/decremented with a constant.
if (binOp != NULL)
{
if (!isConstExpr(binOp->getRight()))
{
error(binOp->getLine(),
"Loop index cannot be modified by non-constant expression",
symbol->getSymbol().c_str());
return false;
}
}
return true;
}
