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/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SKSL_PARSER
#define SKSL_PARSER
#include <vector>
#include <memory>
#include <unordered_map>
#include <unordered_set>
#include "src/sksl/SkSLASTFile.h"
#include "src/sksl/SkSLASTNode.h"
#include "src/sksl/SkSLErrorReporter.h"
#include "src/sksl/SkSLLexer.h"
#include "src/sksl/ir/SkSLLayout.h"
struct yy_buffer_state;
#define YY_TYPEDEF_YY_BUFFER_STATE
typedef struct yy_buffer_state *YY_BUFFER_STATE;
namespace SkSL {
struct Modifiers;
class SymbolTable;
/**
* Consumes .sksl text and produces an abstract syntax tree describing the contents.
*/
class Parser {
public:
enum class LayoutToken {
LOCATION,
OFFSET,
BINDING,
INDEX,
SET,
BUILTIN,
INPUT_ATTACHMENT_INDEX,
ORIGIN_UPPER_LEFT,
OVERRIDE_COVERAGE,
BLEND_SUPPORT_ALL_EQUATIONS,
BLEND_SUPPORT_MULTIPLY,
BLEND_SUPPORT_SCREEN,
BLEND_SUPPORT_OVERLAY,
BLEND_SUPPORT_DARKEN,
BLEND_SUPPORT_LIGHTEN,
BLEND_SUPPORT_COLORDODGE,
BLEND_SUPPORT_COLORBURN,
BLEND_SUPPORT_HARDLIGHT,
BLEND_SUPPORT_SOFTLIGHT,
BLEND_SUPPORT_DIFFERENCE,
BLEND_SUPPORT_EXCLUSION,
BLEND_SUPPORT_HSL_HUE,
BLEND_SUPPORT_HSL_SATURATION,
BLEND_SUPPORT_HSL_COLOR,
BLEND_SUPPORT_HSL_LUMINOSITY,
PUSH_CONSTANT,
POINTS,
LINES,
LINE_STRIP,
LINES_ADJACENCY,
TRIANGLES,
TRIANGLE_STRIP,
TRIANGLES_ADJACENCY,
MAX_VERTICES,
INVOCATIONS,
WHEN,
KEY,
TRACKED,
CTYPE,
SKPMCOLOR4F,
SKV4,
SKRECT,
SKIRECT,
SKPMCOLOR,
SKM44,
BOOL,
INT,
FLOAT,
};
Parser(const char* text, size_t length, SymbolTable& types, ErrorReporter& errors);
/**
* Consumes a complete .sksl file and returns the parse tree. Errors are reported via the
* ErrorReporter; the return value may contain some declarations even when errors have occurred.
*/
std::unique_ptr<ASTFile> file();
StringFragment text(Token token);
Position position(Token token);
private:
static void InitLayoutMap();
/**
* Return the next token, including whitespace tokens, from the parse stream.
*/
Token nextRawToken();
/**
* Return the next non-whitespace token from the parse stream.
*/
Token nextToken();
/**
* Push a token back onto the parse stream, so that it is the next one read. Only a single level
* of pushback is supported (that is, it is an error to call pushback() twice in a row without
* an intervening nextToken()).
*/
void pushback(Token t);
/**
* Returns the next non-whitespace token without consuming it from the stream.
*/
Token peek();
/**
* Checks to see if the next token is of the specified type. If so, stores it in result (if
* result is non-null) and returns true. Otherwise, pushes it back and returns false.
*/
bool checkNext(Token::Kind kind, Token* result = nullptr);
/**
* Reads the next non-whitespace token and generates an error if it is not the expected type.
* The 'expected' string is part of the error message, which reads:
*
* "expected <expected>, but found '<actual text>'"
*
* If 'result' is non-null, it is set to point to the token that was read.
* Returns true if the read token was as expected, false otherwise.
*/
bool expect(Token::Kind kind, const char* expected, Token* result = nullptr);
bool expect(Token::Kind kind, String expected, Token* result = nullptr);
void error(Token token, String msg);
void error(int offset, String msg);
/**
* Returns true if the 'name' identifier refers to a type name. For instance, isType("int") will
* always return true.
*/
bool isType(StringFragment name);
// The pointer to the node may be invalidated by modifying the fNodes vector
ASTNode& getNode(ASTNode::ID id) {
SkASSERT(id.fValue >= 0 && id.fValue < (int) fFile->fNodes.size());
return fFile->fNodes[id.fValue];
}
// these functions parse individual grammar rules from the current parse position; you probably
// don't need to call any of these outside of the parser. The function declarations in the .cpp
// file have comments describing the grammar rules.
ASTNode::ID precision();
ASTNode::ID directive();
ASTNode::ID section();
ASTNode::ID enumDeclaration();
ASTNode::ID declaration();
ASTNode::ID varDeclarations();
ASTNode::ID structDeclaration();
ASTNode::ID structVarDeclaration(Modifiers modifiers);
ASTNode::ID varDeclarationEnd(Modifiers modifiers, ASTNode::ID type, StringFragment name);
ASTNode::ID parameter();
int layoutInt();
StringFragment layoutIdentifier();
StringFragment layoutCode();
Layout::Key layoutKey();
Layout::CType layoutCType();
Layout layout();
Modifiers modifiers();
Modifiers modifiersWithDefaults(int defaultFlags);
ASTNode::ID statement();
ASTNode::ID type();
ASTNode::ID interfaceBlock(Modifiers mods);
ASTNode::ID ifStatement();
ASTNode::ID doStatement();
ASTNode::ID whileStatement();
ASTNode::ID forStatement();
ASTNode::ID switchCase();
ASTNode::ID switchStatement();
ASTNode::ID returnStatement();
ASTNode::ID breakStatement();
ASTNode::ID continueStatement();
ASTNode::ID discardStatement();
ASTNode::ID block();
ASTNode::ID expressionStatement();
ASTNode::ID expression();
ASTNode::ID assignmentExpression();
ASTNode::ID ternaryExpression();
ASTNode::ID logicalOrExpression();
ASTNode::ID logicalXorExpression();
ASTNode::ID logicalAndExpression();
ASTNode::ID bitwiseOrExpression();
ASTNode::ID bitwiseXorExpression();
ASTNode::ID bitwiseAndExpression();
ASTNode::ID equalityExpression();
ASTNode::ID relationalExpression();
ASTNode::ID shiftExpression();
ASTNode::ID additiveExpression();
ASTNode::ID multiplicativeExpression();
ASTNode::ID unaryExpression();
ASTNode::ID postfixExpression();
ASTNode::ID suffix(ASTNode::ID base);
ASTNode::ID term();
bool intLiteral(SKSL_INT* dest);
bool floatLiteral(SKSL_FLOAT* dest);
bool boolLiteral(bool* dest);
bool identifier(StringFragment* dest);
static std::unordered_map<String, LayoutToken>* layoutTokens;
const char* fText;
Lexer fLexer;
YY_BUFFER_STATE fBuffer;
// current parse depth, used to enforce a recursion limit to try to keep us from overflowing the
// stack on pathological inputs
int fDepth = 0;
Token fPushback;
SymbolTable& fTypes;
ErrorReporter& fErrors;
std::unique_ptr<ASTFile> fFile;
friend class AutoDepth;
friend class HCodeGenerator;
};
} // namespace
#endif