blob: b240e4501e98a1f4847cd8c00ca784d854ee9a31 [file] [log] [blame]
/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "stdio.h"
#include "SkSLParser.h"
#include "SkSLToken.h"
#define register
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunneeded-internal-declaration"
#pragma clang diagnostic ignored "-Wnull-conversion"
#pragma clang diagnostic ignored "-Wsign-compare"
#endif
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wsign-compare"
#endif
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable:4018)
#endif
#include "lex.sksl.c"
#ifdef __clang__
#pragma clang diagnostic pop
#endif
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
#ifdef _MSC_VER
#pragma warning(pop)
#endif
#undef register
#include "ast/SkSLASTBinaryExpression.h"
#include "ast/SkSLASTBlock.h"
#include "ast/SkSLASTBoolLiteral.h"
#include "ast/SkSLASTBreakStatement.h"
#include "ast/SkSLASTCallSuffix.h"
#include "ast/SkSLASTContinueStatement.h"
#include "ast/SkSLASTDiscardStatement.h"
#include "ast/SkSLASTDoStatement.h"
#include "ast/SkSLASTExpression.h"
#include "ast/SkSLASTExpressionStatement.h"
#include "ast/SkSLASTExtension.h"
#include "ast/SkSLASTFieldSuffix.h"
#include "ast/SkSLASTFloatLiteral.h"
#include "ast/SkSLASTForStatement.h"
#include "ast/SkSLASTFunction.h"
#include "ast/SkSLASTIdentifier.h"
#include "ast/SkSLASTIfStatement.h"
#include "ast/SkSLASTIndexSuffix.h"
#include "ast/SkSLASTInterfaceBlock.h"
#include "ast/SkSLASTIntLiteral.h"
#include "ast/SkSLASTParameter.h"
#include "ast/SkSLASTPrefixExpression.h"
#include "ast/SkSLASTReturnStatement.h"
#include "ast/SkSLASTStatement.h"
#include "ast/SkSLASTSuffixExpression.h"
#include "ast/SkSLASTTernaryExpression.h"
#include "ast/SkSLASTType.h"
#include "ast/SkSLASTVarDeclaration.h"
#include "ast/SkSLASTVarDeclarationStatement.h"
#include "ast/SkSLASTWhileStatement.h"
#include "ir/SkSLSymbolTable.h"
#include "ir/SkSLType.h"
namespace SkSL {
Parser::Parser(std::string text, SymbolTable& types, ErrorReporter& errors)
: fPushback(Position(-1, -1), Token::INVALID_TOKEN, "")
, fTypes(types)
, fErrors(errors) {
sksllex_init(&fScanner);
fBuffer = sksl_scan_string(text.c_str(), fScanner);
skslset_lineno(1, fScanner);
if (false) {
// avoid unused warning
yyunput(0, nullptr, fScanner);
}
}
Parser::~Parser() {
sksl_delete_buffer(fBuffer, fScanner);
sksllex_destroy(fScanner);
}
/* (precision | directive | declaration)* END_OF_FILE */
std::vector<std::unique_ptr<ASTDeclaration>> Parser::file() {
std::vector<std::unique_ptr<ASTDeclaration>> result;
for (;;) {
switch (this->peek().fKind) {
case Token::END_OF_FILE:
return result;
case Token::PRECISION:
this->precision();
break;
case Token::DIRECTIVE: {
std::unique_ptr<ASTDeclaration> decl = this->directive();
if (decl) {
result.push_back(std::move(decl));
}
break;
}
default: {
std::unique_ptr<ASTDeclaration> decl = this->declaration();
if (!decl) {
continue;
}
result.push_back(std::move(decl));
}
}
}
}
Token Parser::nextToken() {
if (fPushback.fKind != Token::INVALID_TOKEN) {
Token result = fPushback;
fPushback.fKind = Token::INVALID_TOKEN;
fPushback.fText = "";
return result;
}
int token = sksllex(fScanner);
return Token(Position(skslget_lineno(fScanner), -1), (Token::Kind) token,
token == Token::END_OF_FILE ? "<end of file>" :
std::string(skslget_text(fScanner)));
}
void Parser::pushback(Token t) {
ASSERT(fPushback.fKind == Token::INVALID_TOKEN);
fPushback = t;
}
Token Parser::peek() {
fPushback = this->nextToken();
return fPushback;
}
bool Parser::expect(Token::Kind kind, std::string expected, Token* result) {
Token next = this->nextToken();
if (next.fKind == kind) {
if (result) {
*result = next;
}
return true;
} else {
this->error(next.fPosition, "expected " + expected + ", but found '" + next.fText + "'");
return false;
}
}
void Parser::error(Position p, std::string msg) {
fErrors.error(p, msg);
}
bool Parser::isType(std::string name) {
return nullptr != fTypes[name];
}
/* PRECISION (LOWP | MEDIUMP | HIGHP) type SEMICOLON */
void Parser::precision() {
if (!this->expect(Token::PRECISION, "'precision'")) {
return;
}
Token p = this->nextToken();
switch (p.fKind) {
case Token::LOWP: // fall through
case Token::MEDIUMP: // fall through
case Token::HIGHP:
// ignored for now
break;
default:
this->error(p.fPosition, "expected 'lowp', 'mediump', or 'highp', but found '" +
p.fText + "'");
return;
}
if (!this->type()) {
return;
}
this->expect(Token::SEMICOLON, "';'");
}
/* DIRECTIVE(#version) INT_LITERAL | DIRECTIVE(#extension) IDENTIFIER COLON IDENTIFIER */
std::unique_ptr<ASTDeclaration> Parser::directive() {
Token start;
if (!this->expect(Token::DIRECTIVE, "a directive", &start)) {
return nullptr;
}
if (start.fText == "#version") {
this->expect(Token::INT_LITERAL, "a version number");
// ignored for now
return nullptr;
} else if (start.fText == "#extension") {
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
if (!this->expect(Token::COLON, "':'")) {
return nullptr;
}
// FIXME: need to start paying attention to this token
if (!this->expect(Token::IDENTIFIER, "an identifier")) {
return nullptr;
}
return std::unique_ptr<ASTDeclaration>(new ASTExtension(start.fPosition,
std::move(name.fText)));
} else {
this->error(start.fPosition, "unsupported directive '" + start.fText + "'");
return nullptr;
}
}
/* modifiers (structVarDeclaration | type IDENTIFIER ((LPAREN parameter
(COMMA parameter)* RPAREN (block | SEMICOLON)) | SEMICOLON) | interfaceBlock) */
std::unique_ptr<ASTDeclaration> Parser::declaration() {
ASTModifiers modifiers = this->modifiers();
Token lookahead = this->peek();
if (lookahead.fKind == Token::IDENTIFIER && !this->isType(lookahead.fText)) {
// we have an identifier that's not a type, could be the start of an interface block
return this->interfaceBlock(modifiers);
}
if (lookahead.fKind == Token::STRUCT) {
return this->structVarDeclaration(modifiers);
}
std::unique_ptr<ASTType> type(this->type());
if (!type) {
return nullptr;
}
if (type->fKind == ASTType::kStruct_Kind && peek().fKind == Token::SEMICOLON) {
this->nextToken();
return nullptr;
}
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
if (!modifiers.fFlags && this->peek().fKind == Token::LPAREN) {
this->nextToken();
std::vector<std::unique_ptr<ASTParameter>> parameters;
while (this->peek().fKind != Token::RPAREN) {
if (parameters.size() > 0) {
if (!this->expect(Token::COMMA, "','")) {
return nullptr;
}
}
std::unique_ptr<ASTParameter> parameter = this->parameter();
if (!parameter) {
return nullptr;
}
parameters.push_back(std::move(parameter));
}
this->nextToken();
std::unique_ptr<ASTBlock> body;
if (this->peek().fKind == Token::SEMICOLON) {
this->nextToken();
} else {
body = this->block();
if (!body) {
return nullptr;
}
}
return std::unique_ptr<ASTDeclaration>(new ASTFunction(name.fPosition, std::move(type),
std::move(name.fText),
std::move(parameters),
std::move(body)));
} else {
return this->varDeclarationEnd(modifiers, std::move(type), name.fText);
}
}
/* modifiers type IDENTIFIER varDeclarationEnd */
std::unique_ptr<ASTVarDeclarations> Parser::varDeclarations() {
ASTModifiers modifiers = this->modifiers();
std::unique_ptr<ASTType> type(this->type());
if (!type) {
return nullptr;
}
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
return this->varDeclarationEnd(modifiers, std::move(type), std::move(name.fText));
}
/* STRUCT IDENTIFIER LBRACE varDeclaration* RBRACE */
std::unique_ptr<ASTType> Parser::structDeclaration() {
if (!this->expect(Token::STRUCT, "'struct'")) {
return nullptr;
}
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
if (!this->expect(Token::LBRACE, "'{'")) {
return nullptr;
}
std::vector<Type::Field> fields;
while (this->peek().fKind != Token::RBRACE) {
std::unique_ptr<ASTVarDeclarations> decl = this->varDeclarations();
if (!decl) {
return nullptr;
}
for (const auto& var : decl->fVars) {
auto type = (const Type*) fTypes[decl->fType->fName];
for (int i = (int) var.fSizes.size() - 1; i >= 0; i--) {
if (var.fSizes[i]->fKind != ASTExpression::kInt_Kind) {
this->error(decl->fPosition, "array size in struct field must be a constant");
}
uint64_t columns = ((ASTIntLiteral&) *var.fSizes[i]).fValue;
std::string name = type->name() + "[" + to_string(columns) + "]";
type = new Type(name, Type::kArray_Kind, *type, (int) columns);
fTypes.takeOwnership((Type*) type);
}
fields.push_back(Type::Field(decl->fModifiers, var.fName, type));
if (var.fValue) {
this->error(decl->fPosition, "initializers are not permitted on struct fields");
}
}
}
if (!this->expect(Token::RBRACE, "'}'")) {
return nullptr;
}
fTypes.add(name.fText, std::unique_ptr<Type>(new Type(name.fText, fields)));
return std::unique_ptr<ASTType>(new ASTType(name.fPosition, name.fText,
ASTType::kStruct_Kind));
}
/* structDeclaration ((IDENTIFIER varDeclarationEnd) | SEMICOLON) */
std::unique_ptr<ASTVarDeclarations> Parser::structVarDeclaration(ASTModifiers modifiers) {
std::unique_ptr<ASTType> type = this->structDeclaration();
if (!type) {
return nullptr;
}
if (peek().fKind == Token::IDENTIFIER) {
Token name = this->nextToken();
std::unique_ptr<ASTVarDeclarations> result = this->varDeclarationEnd(modifiers,
std::move(type),
std::move(name.fText));
if (result) {
for (const auto& var : result->fVars) {
if (var.fValue) {
this->error(var.fValue->fPosition,
"struct variables cannot be initialized");
}
}
}
return result;
}
this->expect(Token::SEMICOLON, "';'");
return nullptr;
}
/* (LBRACKET expression? RBRACKET)* (EQ expression)? (COMMA IDENTIFER
(LBRACKET expression? RBRACKET)* (EQ expression)?)* SEMICOLON */
std::unique_ptr<ASTVarDeclarations> Parser::varDeclarationEnd(ASTModifiers mods,
std::unique_ptr<ASTType> type,
std::string name) {
std::vector<ASTVarDeclaration> vars;
std::vector<std::unique_ptr<ASTExpression>> currentVarSizes;
while (this->peek().fKind == Token::LBRACKET) {
this->nextToken();
if (this->peek().fKind == Token::RBRACKET) {
this->nextToken();
currentVarSizes.push_back(nullptr);
} else {
std::unique_ptr<ASTExpression> size(this->expression());
if (!size) {
return nullptr;
}
currentVarSizes.push_back(std::move(size));
if (!this->expect(Token::RBRACKET, "']'")) {
return nullptr;
}
}
}
std::unique_ptr<ASTExpression> value;
if (this->peek().fKind == Token::EQ) {
this->nextToken();
value = this->expression();
if (!value) {
return nullptr;
}
}
vars.emplace_back(std::move(name), std::move(currentVarSizes), std::move(value));
while (this->peek().fKind == Token::COMMA) {
this->nextToken();
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
currentVarSizes.clear();
value.reset();
while (this->peek().fKind == Token::LBRACKET) {
this->nextToken();
if (this->peek().fKind == Token::RBRACKET) {
this->nextToken();
currentVarSizes.push_back(nullptr);
} else {
std::unique_ptr<ASTExpression> size(this->expression());
if (!size) {
return nullptr;
}
currentVarSizes.push_back(std::move(size));
if (!this->expect(Token::RBRACKET, "']'")) {
return nullptr;
}
}
}
if (this->peek().fKind == Token::EQ) {
this->nextToken();
value = this->expression();
if (!value) {
return nullptr;
}
}
vars.emplace_back(std::move(name.fText), std::move(currentVarSizes), std::move(value));
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTVarDeclarations>(new ASTVarDeclarations(std::move(mods),
std::move(type),
std::move(vars)));
}
/* modifiers type IDENTIFIER (LBRACKET INT_LITERAL RBRACKET)? */
std::unique_ptr<ASTParameter> Parser::parameter() {
ASTModifiers modifiers = this->modifiersWithDefaults(ASTModifiers::kIn_Flag);
std::unique_ptr<ASTType> type = this->type();
if (!type) {
return nullptr;
}
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
std::vector<int> sizes;
while (this->peek().fKind == Token::LBRACKET) {
this->nextToken();
Token sizeToken;
if (!this->expect(Token::INT_LITERAL, "a positive integer", &sizeToken)) {
return nullptr;
}
sizes.push_back(SkSL::stoi(sizeToken.fText));
if (!this->expect(Token::RBRACKET, "']'")) {
return nullptr;
}
}
return std::unique_ptr<ASTParameter>(new ASTParameter(name.fPosition, modifiers,
std::move(type), name.fText,
std::move(sizes)));
}
/** (EQ INT_LITERAL)? */
int Parser::layoutInt() {
if (!this->expect(Token::EQ, "'='")) {
return -1;
}
Token resultToken;
if (this->expect(Token::INT_LITERAL, "a non-negative integer", &resultToken)) {
return SkSL::stoi(resultToken.fText);
}
return -1;
}
/* LAYOUT LPAREN IDENTIFIER EQ INT_LITERAL (COMMA IDENTIFIER EQ INT_LITERAL)*
RPAREN */
ASTLayout Parser::layout() {
int location = -1;
int binding = -1;
int index = -1;
int set = -1;
int builtin = -1;
bool originUpperLeft = false;
if (this->peek().fKind == Token::LAYOUT) {
this->nextToken();
if (!this->expect(Token::LPAREN, "'('")) {
return ASTLayout(location, binding, index, set, builtin, originUpperLeft);
}
for (;;) {
Token t = this->nextToken();
if (t.fText == "location") {
location = this->layoutInt();
} else if (t.fText == "binding") {
binding = this->layoutInt();
} else if (t.fText == "index") {
index = this->layoutInt();
} else if (t.fText == "set") {
set = this->layoutInt();
} else if (t.fText == "builtin") {
builtin = this->layoutInt();
} else if (t.fText == "origin_upper_left") {
originUpperLeft = true;
} else {
this->error(t.fPosition, ("'" + t.fText +
"' is not a valid layout qualifier").c_str());
}
if (this->peek().fKind == Token::RPAREN) {
this->nextToken();
break;
}
if (!this->expect(Token::COMMA, "','")) {
break;
}
}
}
return ASTLayout(location, binding, index, set, builtin, originUpperLeft);
}
/* layout? (UNIFORM | CONST | IN | OUT | INOUT | LOWP | MEDIUMP | HIGHP | FLAT | NOPERSPECTIVE)* */
ASTModifiers Parser::modifiers() {
ASTLayout layout = this->layout();
int flags = 0;
for (;;) {
// TODO: handle duplicate / incompatible flags
switch (peek().fKind) {
case Token::UNIFORM:
this->nextToken();
flags |= ASTModifiers::kUniform_Flag;
break;
case Token::CONST:
this->nextToken();
flags |= ASTModifiers::kConst_Flag;
break;
case Token::IN:
this->nextToken();
flags |= ASTModifiers::kIn_Flag;
break;
case Token::OUT:
this->nextToken();
flags |= ASTModifiers::kOut_Flag;
break;
case Token::INOUT:
this->nextToken();
flags |= ASTModifiers::kIn_Flag;
flags |= ASTModifiers::kOut_Flag;
break;
case Token::LOWP:
this->nextToken();
flags |= ASTModifiers::kLowp_Flag;
break;
case Token::MEDIUMP:
this->nextToken();
flags |= ASTModifiers::kMediump_Flag;
break;
case Token::HIGHP:
this->nextToken();
flags |= ASTModifiers::kHighp_Flag;
break;
case Token::FLAT:
this->nextToken();
flags |= ASTModifiers::kFlat_Flag;
break;
case Token::NOPERSPECTIVE:
this->nextToken();
flags |= ASTModifiers::kNoPerspective_Flag;
break;
default:
return ASTModifiers(layout, flags);
}
}
}
ASTModifiers Parser::modifiersWithDefaults(int defaultFlags) {
ASTModifiers result = this->modifiers();
if (!result.fFlags) {
return ASTModifiers(result.fLayout, defaultFlags);
}
return result;
}
/* ifStatement | forStatement | doStatement | whileStatement | block | expression */
std::unique_ptr<ASTStatement> Parser::statement() {
Token start = this->peek();
switch (start.fKind) {
case Token::IF:
return this->ifStatement();
case Token::FOR:
return this->forStatement();
case Token::DO:
return this->doStatement();
case Token::WHILE:
return this->whileStatement();
case Token::RETURN:
return this->returnStatement();
case Token::BREAK:
return this->breakStatement();
case Token::CONTINUE:
return this->continueStatement();
case Token::DISCARD:
return this->discardStatement();
case Token::LBRACE:
return this->block();
case Token::SEMICOLON:
this->nextToken();
return std::unique_ptr<ASTStatement>(new ASTBlock(start.fPosition,
std::vector<std::unique_ptr<ASTStatement>>()));
case Token::CONST: // fall through
case Token::HIGHP: // fall through
case Token::MEDIUMP: // fall through
case Token::LOWP: {
auto decl = this->varDeclarations();
if (!decl) {
return nullptr;
}
return std::unique_ptr<ASTStatement>(new ASTVarDeclarationStatement(std::move(decl)));
}
case Token::IDENTIFIER:
if (this->isType(start.fText)) {
auto decl = this->varDeclarations();
if (!decl) {
return nullptr;
}
return std::unique_ptr<ASTStatement>(new ASTVarDeclarationStatement(
std::move(decl)));
}
// fall through
default:
return this->expressionStatement();
}
}
/* IDENTIFIER(type) */
std::unique_ptr<ASTType> Parser::type() {
Token type;
if (!this->expect(Token::IDENTIFIER, "a type", &type)) {
return nullptr;
}
if (!this->isType(type.fText)) {
this->error(type.fPosition, ("no type named '" + type.fText + "'").c_str());
return nullptr;
}
return std::unique_ptr<ASTType>(new ASTType(type.fPosition, std::move(type.fText),
ASTType::kIdentifier_Kind));
}
/* IDENTIFIER LBRACE varDeclaration* RBRACE */
std::unique_ptr<ASTDeclaration> Parser::interfaceBlock(ASTModifiers mods) {
Token name;
if (!this->expect(Token::IDENTIFIER, "an identifier", &name)) {
return nullptr;
}
if (peek().fKind != Token::LBRACE) {
// we only get into interfaceBlock if we found a top-level identifier which was not a type.
// 99% of the time, the user was not actually intending to create an interface block, so
// it's better to report it as an unknown type
this->error(name.fPosition, "no type named '" + name.fText + "'");
return nullptr;
}
this->nextToken();
std::vector<std::unique_ptr<ASTVarDeclarations>> decls;
while (this->peek().fKind != Token::RBRACE) {
std::unique_ptr<ASTVarDeclarations> decl = this->varDeclarations();
if (!decl) {
return nullptr;
}
decls.push_back(std::move(decl));
}
this->nextToken();
std::string valueName;
if (this->peek().fKind == Token::IDENTIFIER) {
valueName = this->nextToken().fText;
}
this->expect(Token::SEMICOLON, "';'");
return std::unique_ptr<ASTDeclaration>(new ASTInterfaceBlock(name.fPosition, mods,
name.fText, std::move(valueName),
std::move(decls)));
}
/* IF LPAREN expression RPAREN statement (ELSE statement)? */
std::unique_ptr<ASTIfStatement> Parser::ifStatement() {
Token start;
if (!this->expect(Token::IF, "'if'", &start)) {
return nullptr;
}
if (!this->expect(Token::LPAREN, "'('")) {
return nullptr;
}
std::unique_ptr<ASTExpression> test(this->expression());
if (!test) {
return nullptr;
}
if (!this->expect(Token::RPAREN, "')'")) {
return nullptr;
}
std::unique_ptr<ASTStatement> ifTrue(this->statement());
if (!ifTrue) {
return nullptr;
}
std::unique_ptr<ASTStatement> ifFalse;
if (this->peek().fKind == Token::ELSE) {
this->nextToken();
ifFalse = this->statement();
if (!ifFalse) {
return nullptr;
}
}
return std::unique_ptr<ASTIfStatement>(new ASTIfStatement(start.fPosition, std::move(test),
std::move(ifTrue),
std::move(ifFalse)));
}
/* DO statement WHILE LPAREN expression RPAREN SEMICOLON */
std::unique_ptr<ASTDoStatement> Parser::doStatement() {
Token start;
if (!this->expect(Token::DO, "'do'", &start)) {
return nullptr;
}
std::unique_ptr<ASTStatement> statement(this->statement());
if (!statement) {
return nullptr;
}
if (!this->expect(Token::WHILE, "'while'")) {
return nullptr;
}
if (!this->expect(Token::LPAREN, "'('")) {
return nullptr;
}
std::unique_ptr<ASTExpression> test(this->expression());
if (!test) {
return nullptr;
}
if (!this->expect(Token::RPAREN, "')'")) {
return nullptr;
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTDoStatement>(new ASTDoStatement(start.fPosition,
std::move(statement),
std::move(test)));
}
/* WHILE LPAREN expression RPAREN STATEMENT */
std::unique_ptr<ASTWhileStatement> Parser::whileStatement() {
Token start;
if (!this->expect(Token::WHILE, "'while'", &start)) {
return nullptr;
}
if (!this->expect(Token::LPAREN, "'('")) {
return nullptr;
}
std::unique_ptr<ASTExpression> test(this->expression());
if (!test) {
return nullptr;
}
if (!this->expect(Token::RPAREN, "')'")) {
return nullptr;
}
std::unique_ptr<ASTStatement> statement(this->statement());
if (!statement) {
return nullptr;
}
return std::unique_ptr<ASTWhileStatement>(new ASTWhileStatement(start.fPosition,
std::move(test),
std::move(statement)));
}
/* FOR LPAREN (declaration | expression)? SEMICOLON expression? SEMICOLON expression? RPAREN
STATEMENT */
std::unique_ptr<ASTForStatement> Parser::forStatement() {
Token start;
if (!this->expect(Token::FOR, "'for'", &start)) {
return nullptr;
}
if (!this->expect(Token::LPAREN, "'('")) {
return nullptr;
}
std::unique_ptr<ASTStatement> initializer;
Token nextToken = this->peek();
switch (nextToken.fKind) {
case Token::SEMICOLON:
break;
case Token::CONST:
initializer = std::unique_ptr<ASTStatement>(new ASTVarDeclarationStatement(
this->varDeclarations()));
break;
case Token::IDENTIFIER:
if (this->isType(nextToken.fText)) {
initializer = std::unique_ptr<ASTStatement>(new ASTVarDeclarationStatement(
this->varDeclarations()));
break;
}
// fall through
default:
initializer = this->expressionStatement();
}
std::unique_ptr<ASTExpression> test;
if (this->peek().fKind != Token::SEMICOLON) {
test = this->expression();
if (!test) {
return nullptr;
}
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
std::unique_ptr<ASTExpression> next;
if (this->peek().fKind != Token::SEMICOLON) {
next = this->expression();
if (!next) {
return nullptr;
}
}
if (!this->expect(Token::RPAREN, "')'")) {
return nullptr;
}
std::unique_ptr<ASTStatement> statement(this->statement());
if (!statement) {
return nullptr;
}
return std::unique_ptr<ASTForStatement>(new ASTForStatement(start.fPosition,
std::move(initializer),
std::move(test), std::move(next),
std::move(statement)));
}
/* RETURN expression? SEMICOLON */
std::unique_ptr<ASTReturnStatement> Parser::returnStatement() {
Token start;
if (!this->expect(Token::RETURN, "'return'", &start)) {
return nullptr;
}
std::unique_ptr<ASTExpression> expression;
if (this->peek().fKind != Token::SEMICOLON) {
expression = this->expression();
if (!expression) {
return nullptr;
}
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTReturnStatement>(new ASTReturnStatement(start.fPosition,
std::move(expression)));
}
/* BREAK SEMICOLON */
std::unique_ptr<ASTBreakStatement> Parser::breakStatement() {
Token start;
if (!this->expect(Token::BREAK, "'break'", &start)) {
return nullptr;
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTBreakStatement>(new ASTBreakStatement(start.fPosition));
}
/* CONTINUE SEMICOLON */
std::unique_ptr<ASTContinueStatement> Parser::continueStatement() {
Token start;
if (!this->expect(Token::CONTINUE, "'continue'", &start)) {
return nullptr;
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTContinueStatement>(new ASTContinueStatement(start.fPosition));
}
/* DISCARD SEMICOLON */
std::unique_ptr<ASTDiscardStatement> Parser::discardStatement() {
Token start;
if (!this->expect(Token::DISCARD, "'continue'", &start)) {
return nullptr;
}
if (!this->expect(Token::SEMICOLON, "';'")) {
return nullptr;
}
return std::unique_ptr<ASTDiscardStatement>(new ASTDiscardStatement(start.fPosition));
}
/* LBRACE statement* RBRACE */
std::unique_ptr<ASTBlock> Parser::block() {
Token start;
if (!this->expect(Token::LBRACE, "'{'", &start)) {
return nullptr;
}
std::vector<std::unique_ptr<ASTStatement>> statements;
for (;;) {
switch (this->peek().fKind) {
case Token::RBRACE:
this->nextToken();
return std::unique_ptr<ASTBlock>(new ASTBlock(start.fPosition,
std::move(statements)));
case Token::END_OF_FILE:
this->error(this->peek().fPosition, "expected '}', but found end of file");
return nullptr;
default: {
std::unique_ptr<ASTStatement> statement = this->statement();
if (!statement) {
return nullptr;
}
statements.push_back(std::move(statement));
}
}
}
}
/* expression SEMICOLON */
std::unique_ptr<ASTExpressionStatement> Parser::expressionStatement() {
std::unique_ptr<ASTExpression> expr = this->expression();
if (expr) {
if (this->expect(Token::SEMICOLON, "';'")) {
ASTExpressionStatement* result = new ASTExpressionStatement(std::move(expr));
return std::unique_ptr<ASTExpressionStatement>(result);
}
}
return nullptr;
}
/* assignmentExpression */
std::unique_ptr<ASTExpression> Parser::expression() {
return this->assignmentExpression();
}
/* ternaryExpression ((EQEQ | STAREQ | SLASHEQ | PERCENTEQ | PLUSEQ | MINUSEQ | SHLEQ | SHREQ |
BITWISEANDEQ | BITWISEXOREQ | BITWISEOREQ | LOGICALANDEQ | LOGICALXOREQ | LOGICALOREQ)
assignmentExpression)*
*/
std::unique_ptr<ASTExpression> Parser::assignmentExpression() {
std::unique_ptr<ASTExpression> result = this->ternaryExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::EQ: // fall through
case Token::STAREQ: // fall through
case Token::SLASHEQ: // fall through
case Token::PERCENTEQ: // fall through
case Token::PLUSEQ: // fall through
case Token::MINUSEQ: // fall through
case Token::SHLEQ: // fall through
case Token::SHREQ: // fall through
case Token::BITWISEANDEQ: // fall through
case Token::BITWISEXOREQ: // fall through
case Token::BITWISEOREQ: // fall through
case Token::LOGICALANDEQ: // fall through
case Token::LOGICALXOREQ: // fall through
case Token::LOGICALOREQ: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->assignmentExpression();
if (!right) {
return nullptr;
}
result = std::unique_ptr<ASTExpression>(new ASTBinaryExpression(std::move(result),
t,
std::move(right)));
}
default:
return result;
}
}
}
/* logicalOrExpression ('?' expression ':' assignmentExpression)? */
std::unique_ptr<ASTExpression> Parser::ternaryExpression() {
std::unique_ptr<ASTExpression> result = this->logicalOrExpression();
if (!result) {
return nullptr;
}
if (this->peek().fKind == Token::QUESTION) {
Token question = this->nextToken();
std::unique_ptr<ASTExpression> trueExpr = this->expression();
if (!trueExpr) {
return nullptr;
}
if (this->expect(Token::COLON, "':'")) {
std::unique_ptr<ASTExpression> falseExpr = this->assignmentExpression();
return std::unique_ptr<ASTExpression>(new ASTTernaryExpression(std::move(result),
std::move(trueExpr),
std::move(falseExpr)));
}
return nullptr;
}
return result;
}
/* logicalXorExpression (LOGICALOR logicalXorExpression)* */
std::unique_ptr<ASTExpression> Parser::logicalOrExpression() {
std::unique_ptr<ASTExpression> result = this->logicalXorExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::LOGICALOR) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->logicalXorExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* logicalAndExpression (LOGICALXOR logicalAndExpression)* */
std::unique_ptr<ASTExpression> Parser::logicalXorExpression() {
std::unique_ptr<ASTExpression> result = this->logicalAndExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::LOGICALXOR) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->logicalAndExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* bitwiseOrExpression (LOGICALAND bitwiseOrExpression)* */
std::unique_ptr<ASTExpression> Parser::logicalAndExpression() {
std::unique_ptr<ASTExpression> result = this->bitwiseOrExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::LOGICALAND) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->bitwiseOrExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* bitwiseXorExpression (BITWISEOR bitwiseXorExpression)* */
std::unique_ptr<ASTExpression> Parser::bitwiseOrExpression() {
std::unique_ptr<ASTExpression> result = this->bitwiseXorExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::BITWISEOR) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->bitwiseXorExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* bitwiseAndExpression (BITWISEXOR bitwiseAndExpression)* */
std::unique_ptr<ASTExpression> Parser::bitwiseXorExpression() {
std::unique_ptr<ASTExpression> result = this->bitwiseAndExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::BITWISEXOR) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->bitwiseAndExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* equalityExpression (BITWISEAND equalityExpression)* */
std::unique_ptr<ASTExpression> Parser::bitwiseAndExpression() {
std::unique_ptr<ASTExpression> result = this->equalityExpression();
if (!result) {
return nullptr;
}
while (this->peek().fKind == Token::BITWISEAND) {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->equalityExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
}
return result;
}
/* relationalExpression ((EQEQ | NEQ) relationalExpression)* */
std::unique_ptr<ASTExpression> Parser::equalityExpression() {
std::unique_ptr<ASTExpression> result = this->relationalExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::EQEQ: // fall through
case Token::NEQ: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->relationalExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
break;
}
default:
return result;
}
}
}
/* shiftExpression ((LT | GT | LTEQ | GTEQ) shiftExpression)* */
std::unique_ptr<ASTExpression> Parser::relationalExpression() {
std::unique_ptr<ASTExpression> result = this->shiftExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::LT: // fall through
case Token::GT: // fall through
case Token::LTEQ: // fall through
case Token::GTEQ: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->shiftExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
break;
}
default:
return result;
}
}
}
/* additiveExpression ((SHL | SHR) additiveExpression)* */
std::unique_ptr<ASTExpression> Parser::shiftExpression() {
std::unique_ptr<ASTExpression> result = this->additiveExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::SHL: // fall through
case Token::SHR: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->additiveExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
break;
}
default:
return result;
}
}
}
/* multiplicativeExpression ((PLUS | MINUS) multiplicativeExpression)* */
std::unique_ptr<ASTExpression> Parser::additiveExpression() {
std::unique_ptr<ASTExpression> result = this->multiplicativeExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::PLUS: // fall through
case Token::MINUS: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->multiplicativeExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
break;
}
default:
return result;
}
}
}
/* unaryExpression ((STAR | SLASH | PERCENT) unaryExpression)* */
std::unique_ptr<ASTExpression> Parser::multiplicativeExpression() {
std::unique_ptr<ASTExpression> result = this->unaryExpression();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::STAR: // fall through
case Token::SLASH: // fall through
case Token::PERCENT: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> right = this->unaryExpression();
if (!right) {
return nullptr;
}
result.reset(new ASTBinaryExpression(std::move(result), t, std::move(right)));
break;
}
default:
return result;
}
}
}
/* postfixExpression | (PLUS | MINUS | NOT | PLUSPLUS | MINUSMINUS) unaryExpression */
std::unique_ptr<ASTExpression> Parser::unaryExpression() {
switch (this->peek().fKind) {
case Token::PLUS: // fall through
case Token::MINUS: // fall through
case Token::NOT: // fall through
case Token::PLUSPLUS: // fall through
case Token::MINUSMINUS: {
Token t = this->nextToken();
std::unique_ptr<ASTExpression> expr = this->unaryExpression();
if (!expr) {
return nullptr;
}
return std::unique_ptr<ASTExpression>(new ASTPrefixExpression(t, std::move(expr)));
}
default:
return this->postfixExpression();
}
}
/* term suffix* */
std::unique_ptr<ASTExpression> Parser::postfixExpression() {
std::unique_ptr<ASTExpression> result = this->term();
if (!result) {
return nullptr;
}
for (;;) {
switch (this->peek().fKind) {
case Token::LBRACKET: // fall through
case Token::DOT: // fall through
case Token::LPAREN: // fall through
case Token::PLUSPLUS: // fall through
case Token::MINUSMINUS: {
std::unique_ptr<ASTSuffix> s = this->suffix();
if (!s) {
return nullptr;
}
result.reset(new ASTSuffixExpression(std::move(result), std::move(s)));
break;
}
default:
return result;
}
}
}
/* LBRACKET expression RBRACKET | DOT IDENTIFIER | LPAREN parameters RPAREN |
PLUSPLUS | MINUSMINUS */
std::unique_ptr<ASTSuffix> Parser::suffix() {
Token next = this->nextToken();
switch (next.fKind) {
case Token::LBRACKET: {
std::unique_ptr<ASTExpression> e = this->expression();
if (!e) {
return nullptr;
}
this->expect(Token::RBRACKET, "']' to complete array access expression");
return std::unique_ptr<ASTSuffix>(new ASTIndexSuffix(std::move(e)));
}
case Token::DOT: {
Position pos = this->peek().fPosition;
std::string text;
if (this->identifier(&text)) {
return std::unique_ptr<ASTSuffix>(new ASTFieldSuffix(pos, std::move(text)));
}
return nullptr;
}
case Token::LPAREN: {
std::vector<std::unique_ptr<ASTExpression>> parameters;
if (this->peek().fKind != Token::RPAREN) {
for (;;) {
std::unique_ptr<ASTExpression> expr = this->expression();
if (!expr) {
return nullptr;
}
parameters.push_back(std::move(expr));
if (this->peek().fKind != Token::COMMA) {
break;
}
this->nextToken();
}
}
this->expect(Token::RPAREN, "')' to complete function parameters");
return std::unique_ptr<ASTSuffix>(new ASTCallSuffix(next.fPosition,
std::move(parameters)));
}
case Token::PLUSPLUS:
return std::unique_ptr<ASTSuffix>(new ASTSuffix(next.fPosition,
ASTSuffix::kPostIncrement_Kind));
case Token::MINUSMINUS:
return std::unique_ptr<ASTSuffix>(new ASTSuffix(next.fPosition,
ASTSuffix::kPostDecrement_Kind));
default: {
this->error(next.fPosition, "expected expression suffix, but found '" + next.fText +
"'\n");
return nullptr;
}
}
}
/* IDENTIFIER | intLiteral | floatLiteral | boolLiteral | '(' expression ')' */
std::unique_ptr<ASTExpression> Parser::term() {
std::unique_ptr<ASTExpression> result;
Token t = this->peek();
switch (t.fKind) {
case Token::IDENTIFIER: {
std::string text;
if (this->identifier(&text)) {
result.reset(new ASTIdentifier(t.fPosition, std::move(text)));
}
break;
}
case Token::INT_LITERAL: {
int64_t i;
if (this->intLiteral(&i)) {
result.reset(new ASTIntLiteral(t.fPosition, i));
}
break;
}
case Token::FLOAT_LITERAL: {
double f;
if (this->floatLiteral(&f)) {
result.reset(new ASTFloatLiteral(t.fPosition, f));
}
break;
}
case Token::TRUE_LITERAL: // fall through
case Token::FALSE_LITERAL: {
bool b;
if (this->boolLiteral(&b)) {
result.reset(new ASTBoolLiteral(t.fPosition, b));
}
break;
}
case Token::LPAREN: {
this->nextToken();
result = this->expression();
if (result) {
this->expect(Token::RPAREN, "')' to complete expression");
}
break;
}
default:
this->nextToken();
this->error(t.fPosition, "expected expression, but found '" + t.fText + "'\n");
result = nullptr;
}
return result;
}
/* INT_LITERAL */
bool Parser::intLiteral(int64_t* dest) {
Token t;
if (this->expect(Token::INT_LITERAL, "integer literal", &t)) {
*dest = SkSL::stol(t.fText);
return true;
}
return false;
}
/* FLOAT_LITERAL */
bool Parser::floatLiteral(double* dest) {
Token t;
if (this->expect(Token::FLOAT_LITERAL, "float literal", &t)) {
*dest = SkSL::stod(t.fText);
return true;
}
return false;
}
/* TRUE_LITERAL | FALSE_LITERAL */
bool Parser::boolLiteral(bool* dest) {
Token t = this->nextToken();
switch (t.fKind) {
case Token::TRUE_LITERAL:
*dest = true;
return true;
case Token::FALSE_LITERAL:
*dest = false;
return true;
default:
this->error(t.fPosition, "expected 'true' or 'false', but found '" + t.fText + "'\n");
return false;
}
}
/* IDENTIFIER */
bool Parser::identifier(std::string* dest) {
Token t;
if (this->expect(Token::IDENTIFIER, "identifier", &t)) {
*dest = t.fText;
return true;
}
return false;
}
} // namespace