glslang/hlsl/hlslGrammar.cpp

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//
//Copyright (C) 2016 Google, Inc.
//
//All rights reserved.
//
//Redistribution and use in source and binary forms, with or without
//modification, are permitted provided that the following conditions
//are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
//
// Neither the name of Google, Inc., nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
//THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
//CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
//LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
//ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
//POSSIBILITY OF SUCH DAMAGE.
//
//
// This is a set of mutually recursive methods implementing the HLSL grammar.
// Generally, each returns
// - through an argument: a type specifically appropriate to which rule it
// recognized
// - through the return value: true/false to indicate whether or not it
// recognized its rule
//
// As much as possible, only grammar recognition should happen in this file,
// with all other work being farmed out to hlslParseHelper.cpp, which in turn
// will build the AST.
//
// The next token, yet to be "accepted" is always sitting in 'token'.
// When a method says it accepts a rule, that means all tokens involved
// in the rule will have been consumed, and none left in 'token'.
//
#include "hlslTokens.h"
#include "hlslGrammar.h"
namespace glslang {
// Root entry point to this recursive decent parser.
// Return true if compilation unit was successfully accepted.
bool HlslGrammar::parse()
{
advanceToken();
return acceptCompilationUnit();
}
void HlslGrammar::expected(const char* syntax)
{
parseContext.error(token.loc, "Expected", syntax, "");
}
// Only process the next token if it is an identifier.
// Return true if it was an identifier.
bool HlslGrammar::acceptIdentifier(HlslToken& idToken)
{
if (peekTokenClass(EHTokIdentifier)) {
idToken = token;
advanceToken();
return true;
}
return false;
}
// compilationUnit
// : list of externalDeclaration
//
bool HlslGrammar::acceptCompilationUnit()
{
TIntermNode* unitNode = nullptr;
while (! peekTokenClass(EHTokNone)) {
// externalDeclaration
TIntermNode* declarationNode;
if (! acceptDeclaration(declarationNode))
return false;
// hook it up
unitNode = intermediate.growAggregate(unitNode, declarationNode);
}
// set root of AST
intermediate.setTreeRoot(unitNode);
return true;
}
// declaration
// : SEMICOLON
// : fully_specified_type SEMICOLON
// | fully_specified_type identifier SEMICOLON
// | fully_specified_type identifier = expression SEMICOLON
// | fully_specified_type identifier function_parameters SEMICOLON // function prototype
// | fully_specified_type identifier function_parameters COLON semantic compound_statement // function definition
//
// 'node' could get created if the declaration creates code, like an initializer
// or a function body.
//
bool HlslGrammar::acceptDeclaration(TIntermNode*& node)
{
node = nullptr;
// fully_specified_type
TType type;
if (! acceptFullySpecifiedType(type))
return false;
// identifier
HlslToken idToken;
if (acceptIdentifier(idToken)) {
// = expression
TIntermTyped* expressionNode = nullptr;
if (acceptTokenClass(EHTokEqual)) {
if (! acceptExpression(expressionNode)) {
expected("initializer");
return false;
}
}
// SEMICOLON
if (acceptTokenClass(EHTokSemicolon)) {
node = parseContext.declareVariable(idToken.loc, *idToken.string, type, 0, expressionNode);
return true;
}
// function_parameters
TFunction* function = new TFunction(idToken.string, type);
if (acceptFunctionParameters(*function)) {
// COLON semantic
acceptSemantic();
// compound_statement
if (peekTokenClass(EHTokLeftBrace))
return acceptFunctionDefinition(*function, node);
// SEMICOLON
if (acceptTokenClass(EHTokSemicolon))
return true;
return false;
}
}
// SEMICOLON
if (acceptTokenClass(EHTokSemicolon))
return true;
return true;
}
// fully_specified_type
// : type_specifier
// | type_qualifier type_specifier
//
bool HlslGrammar::acceptFullySpecifiedType(TType& type)
{
// type_qualifier
TQualifier qualifier;
qualifier.clear();
acceptQualifier(qualifier);
// type_specifier
if (! acceptType(type))
return false;
type.getQualifier() = qualifier;
return true;
}
// If token is a qualifier, return its token class and advance to the next
// qualifier. Otherwise, return false, and don't advance.
void HlslGrammar::acceptQualifier(TQualifier& qualifier)
{
switch (peek()) {
case EHTokUniform:
qualifier.storage = EvqUniform;
break;
case EHTokConst:
qualifier.storage = EvqConst;
break;
default:
return;
}
advanceToken();
}
// If token is for a type, update 'type' with the type information,
// and return true and advance.
// Otherwise, return false, and don't advance
bool HlslGrammar::acceptType(TType& type)
{
if (! token.isType)
return false;
switch (peek()) {
case EHTokInt:
case EHTokInt1:
case EHTokDword:
new(&type) TType(EbtInt);
break;
case EHTokFloat:
case EHTokFloat1:
new(&type) TType(EbtFloat);
break;
case EHTokFloat2:
new(&type) TType(EbtFloat, EvqTemporary, 2);
break;
case EHTokFloat3:
new(&type) TType(EbtFloat, EvqTemporary, 3);
break;
case EHTokFloat4:
new(&type) TType(EbtFloat, EvqTemporary, 4);
break;
case EHTokInt2:
new(&type) TType(EbtInt, EvqTemporary, 2);
break;
case EHTokInt3:
new(&type) TType(EbtInt, EvqTemporary, 3);
break;
case EHTokInt4:
new(&type) TType(EbtInt, EvqTemporary, 4);
break;
case EHTokBool2:
new(&type) TType(EbtBool, EvqTemporary, 2);
break;
case EHTokBool3:
new(&type) TType(EbtBool, EvqTemporary, 3);
break;
case EHTokBool4:
new(&type) TType(EbtBool, EvqTemporary, 4);
break;
case EHTokFloat2x2:
new(&type) TType(EbtFloat, EvqTemporary, 0, 2, 2);
break;
case EHTokFloat2x3:
new(&type) TType(EbtFloat, EvqTemporary, 0, 3, 2);
break;
case EHTokFloat2x4:
new(&type) TType(EbtFloat, EvqTemporary, 0, 4, 2);
break;
case EHTokFloat3x2:
new(&type) TType(EbtFloat, EvqTemporary, 0, 2, 3);
break;
case EHTokFloat3x3:
new(&type) TType(EbtFloat, EvqTemporary, 0, 3, 3);
break;
case EHTokFloat3x4:
new(&type) TType(EbtFloat, EvqTemporary, 0, 4, 3);
break;
case EHTokFloat4x2:
new(&type) TType(EbtFloat, EvqTemporary, 0, 2, 4);
break;
case EHTokFloat4x3:
new(&type) TType(EbtFloat, EvqTemporary, 0, 3, 4);
break;
case EHTokFloat4x4:
new(&type) TType(EbtFloat, EvqTemporary, 0, 4, 4);
break;
default:
return false;
}
advanceToken();
return true;
}
// function_parameters
// : LEFT_PAREN parameter_declaration COMMA parameter_declaration ... RIGHT_PAREN
//
bool HlslGrammar::acceptFunctionParameters(TFunction& function)
{
// LEFT_PAREN
if (! acceptTokenClass(EHTokLeftParen))
return false;
do {
// parameter_declaration
if (! acceptParameterDeclaration(function))
break;
// COMMA
if (! acceptTokenClass(EHTokComma))
break;
} while (true);
// RIGHT_PAREN
if (! acceptTokenClass(EHTokRightParen)) {
expected("right parenthesis");
return false;
}
return true;
}
// parameter_declaration
// : fully_specified_type
// | fully_specified_type identifier
//
bool HlslGrammar::acceptParameterDeclaration(TFunction& function)
{
// fully_specified_type
TType* type = new TType;
if (! acceptFullySpecifiedType(*type))
return false;
// identifier
HlslToken idToken;
acceptIdentifier(idToken);
TParameter param = { idToken.string, type };
function.addParameter(param);
return true;
}
// Do the work to create the function definition in addition to
// parsing the body (compound_statement).
bool HlslGrammar::acceptFunctionDefinition(TFunction& function, TIntermNode*& node)
{
TFunction* functionDeclarator = parseContext.handleFunctionDeclarator(token.loc, function, false /* not prototype */);
// This does a symbol table push
node = parseContext.handleFunctionDefinition(token.loc, *functionDeclarator);
// compound_statement
TIntermAggregate* functionBody = nullptr;
if (acceptCompoundStatement(functionBody)) {
node = intermediate.growAggregate(node, functionBody);
intermediate.setAggregateOperator(node, EOpFunction, functionDeclarator->getType(), token.loc);
node->getAsAggregate()->setName(functionDeclarator->getMangledName().c_str());
parseContext.symbolTable.pop(nullptr);
return true;
}
return false;
}
// expression
// : identifier
// | identifier operator identifier // todo: generalize to all expressions
// | LEFT_PAREN expression RIGHT_PAREN
// | constructor
// | literal
//
bool HlslGrammar::acceptExpression(TIntermTyped*& node)
{
// identifier
HlslToken idToken;
if (acceptIdentifier(idToken)) {
TIntermTyped* left = parseContext.handleVariable(idToken.loc, idToken.symbol, token.string);
// operator?
TOperator op;
if (! acceptOperator(op))
return true;
TSourceLoc loc = token.loc;
// identifier
if (acceptIdentifier(idToken)) {
TIntermTyped* right = parseContext.handleVariable(idToken.loc, idToken.symbol, token.string);
node = intermediate.addBinaryMath(op, left, right, loc);
return true;
}
return false;
}
// LEFT_PAREN expression RIGHT_PAREN
if (acceptTokenClass(EHTokLeftParen)) {
if (! acceptExpression(node)) {
expected("expression");
return false;
}
if (! acceptTokenClass(EHTokRightParen)) {
expected("right parenthesis");
return false;
}
return true;
}
// literal
if (acceptLiteral(node))
return true;
// constructor
if (acceptConstructor(node))
return true;
return false;
}
// constructor
// : type argument_list
//
bool HlslGrammar::acceptConstructor(TIntermTyped*& node)
{
// type
TType type;
if (acceptType(type)) {
TFunction* constructorFunction = parseContext.handleConstructorCall(token.loc, type);
if (constructorFunction == nullptr)
return false;
// arguments
TIntermAggregate* arguments = nullptr;
if (! acceptArguments(constructorFunction, arguments)) {
expected("constructor arguments");
return false;
}
// hook it up
node = parseContext.handleFunctionCall(arguments->getLoc(), constructorFunction, arguments);
return true;
}
return false;
}
// arguments
// : LEFT_PAREN expression COMMA expression COMMA ... RIGHT_PAREN
//
// The arguments are pushed onto the 'function' argument list and
// onto the 'arguments' aggregate.
//
bool HlslGrammar::acceptArguments(TFunction* function, TIntermAggregate*& arguments)
{
// LEFT_PAREN
if (! acceptTokenClass(EHTokLeftParen))
return false;
do {
// expression
TIntermTyped* arg;
if (! acceptExpression(arg))
break;
// hook it up
parseContext.handleFunctionArgument(function, arguments, arg);
// COMMA
if (! acceptTokenClass(EHTokComma))
break;
} while (true);
// RIGHT_PAREN
if (! acceptTokenClass(EHTokRightParen)) {
expected("right parenthesis");
return false;
}
return true;
}
bool HlslGrammar::acceptLiteral(TIntermTyped*& node)
{
switch (token.tokenClass) {
case EHTokIntConstant:
node = intermediate.addConstantUnion(token.i, token.loc, true);
break;
case EHTokFloatConstant:
node = intermediate.addConstantUnion(token.d, EbtFloat, token.loc, true);
break;
case EHTokDoubleConstant:
node = intermediate.addConstantUnion(token.d, EbtDouble, token.loc, true);
break;
case EHTokBoolConstant:
node = intermediate.addConstantUnion(token.b, token.loc, true);
break;
default:
return false;
}
advanceToken();
return true;
}
// operator
// : PLUS | DASH | STAR | SLASH | ...
bool HlslGrammar::acceptOperator(TOperator& op)
{
switch (token.tokenClass) {
case EHTokEqual:
op = EOpAssign;
break;
case EHTokPlus:
op = EOpAdd;
break;
case EHTokDash:
op = EOpSub;
break;
case EHTokStar:
op = EOpMul;
break;
case EHTokSlash:
op = EOpDiv;
break;
default:
return false;
}
advanceToken();
return true;
}
// compound_statement
// : { statement statement ... }
//
bool HlslGrammar::acceptCompoundStatement(TIntermAggregate*& compoundStatement)
{
// {
if (! acceptTokenClass(EHTokLeftBrace))
return false;
// statement statement ...
TIntermNode* statement = nullptr;
while (acceptStatement(statement)) {
// hook it up
compoundStatement = intermediate.growAggregate(compoundStatement, statement);
}
compoundStatement->setOperator(EOpSequence);
// }
return acceptTokenClass(EHTokRightBrace);
}
// statement
// : compound_statement
// | return SEMICOLON
// | return expression SEMICOLON
// | expression SEMICOLON
//
bool HlslGrammar::acceptStatement(TIntermNode*& statement)
{
// compound_statement
TIntermAggregate* compoundStatement = nullptr;
if (acceptCompoundStatement(compoundStatement)) {
statement = compoundStatement;
return true;
}
// RETURN
if (acceptTokenClass(EHTokReturn)) {
// expression
TIntermTyped* node;
if (acceptExpression(node)) {
// hook it up
statement = intermediate.addBranch(EOpReturn, node, token.loc);
} else
statement = intermediate.addBranch(EOpReturn, token.loc);
// SEMICOLON
if (! acceptTokenClass(EHTokSemicolon))
return false;
return true;
}
// expression
TIntermTyped* node;
if (acceptExpression(node))
statement = node;
// SEMICOLON
if (! acceptTokenClass(EHTokSemicolon))
return false;
return true;
}
// COLON semantic
bool HlslGrammar::acceptSemantic()
{
// COLON
if (acceptTokenClass(EHTokColon)) {
// semantic
HlslToken idToken;
if (! acceptIdentifier(idToken)) {
expected("semantic");
return false;
}
}
return true;
}
} // end namespace glslang