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// Copyright 2011 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef NINJA_LEXER_H_
#define NINJA_LEXER_H_
#include "string_piece.h"
// Windows may #define ERROR.
#ifdef ERROR
#undef ERROR
#endif
struct EvalString;
struct Lexer {
Lexer() {}
/// Helper ctor useful for tests.
explicit Lexer(const char* input);
enum Token {
ERROR,
BUILD,
COLON,
DEFAULT,
EQUALS,
IDENT,
INCLUDE,
INDENT,
NEWLINE,
PIPE,
PIPE2,
POOL,
RULE,
SUBNINJA,
TEOF,
};
/// Return a human-readable form of a token, used in error messages.
static const char* TokenName(Token t);
/// Return a human-readable token hint, used in error messages.
static const char* TokenErrorHint(Token expected);
/// If the last token read was an ERROR token, provide more info
/// or the empty string.
string DescribeLastError();
/// Start parsing some input.
void Start(StringPiece filename, StringPiece input);
/// Read a Token from the Token enum.
Token ReadToken();
/// Rewind to the last read Token.
void UnreadToken();
/// If the next token is \a token, read it and return true.
bool PeekToken(Token token);
/// Read a simple identifier (a rule or variable name).
/// Returns false if a name can't be read.
bool ReadIdent(string* out);
/// Read a path (complete with $escapes).
/// Returns false only on error, returned path may be empty if a delimiter
/// (space, newline) is hit.
bool ReadPath(EvalString* path, string* err) {
return ReadEvalString(path, true, err);
}
/// Read the value side of a var = value line (complete with $escapes).
/// Returns false only on error.
bool ReadVarValue(EvalString* value, string* err) {
return ReadEvalString(value, false, err);
}
/// Construct an error message with context.
bool Error(const string& message, string* err);
private:
/// Skip past whitespace (called after each read token/ident/etc.).
void EatWhitespace();
/// Read a $-escaped string.
bool ReadEvalString(EvalString* eval, bool path, string* err);
StringPiece filename_;
StringPiece input_;
const char* ofs_;
const char* last_token_;
};
#endif // NINJA_LEXER_H_