llvm-project/clang/lib/Parse/RAIIObjectsForParser.h

103 lines
3.2 KiB
C++

//===--- RAIIObjectsForParser.h - RAII helpers for the parser ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines and implements the some simple RAII objects that are used
// by the parser to manage bits in recursion.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H
#define LLVM_CLANG_PARSE_RAII_OBJECTS_FOR_PARSER_H
#include "clang/Parse/ParseDiagnostic.h"
namespace clang {
// TODO: move ParsingDeclRAIIObject here.
// TODO: move ParsingClassDefinition here.
// TODO: move TentativeParsingAction here.
/// ExtensionRAIIObject - This saves the state of extension warnings when
/// constructed and disables them. When destructed, it restores them back to
/// the way they used to be. This is used to handle __extension__ in the
/// parser.
class ExtensionRAIIObject {
void operator=(const ExtensionRAIIObject &); // DO NOT IMPLEMENT
ExtensionRAIIObject(const ExtensionRAIIObject&); // DO NOT IMPLEMENT
Diagnostic &Diags;
public:
ExtensionRAIIObject(Diagnostic &diags) : Diags(diags) {
Diags.IncrementAllExtensionsSilenced();
}
~ExtensionRAIIObject() {
Diags.DecrementAllExtensionsSilenced();
}
};
/// ColonProtectionRAIIObject - This sets the Parser::ColonIsSacred bool and
/// restores it when destroyed. This says that "foo:" should not be
/// considered a possible typo for "foo::" for error recovery purposes.
class ColonProtectionRAIIObject {
Parser &P;
bool OldVal;
public:
ColonProtectionRAIIObject(Parser &p, bool Value = true)
: P(p), OldVal(P.ColonIsSacred) {
P.ColonIsSacred = Value;
}
/// restore - This can be used to restore the state early, before the dtor
/// is run.
void restore() {
P.ColonIsSacred = OldVal;
}
~ColonProtectionRAIIObject() {
restore();
}
};
/// \brief RAII object that makes '>' behave either as an operator
/// or as the closing angle bracket for a template argument list.
class GreaterThanIsOperatorScope {
bool &GreaterThanIsOperator;
bool OldGreaterThanIsOperator;
public:
GreaterThanIsOperatorScope(bool &GTIO, bool Val)
: GreaterThanIsOperator(GTIO), OldGreaterThanIsOperator(GTIO) {
GreaterThanIsOperator = Val;
}
~GreaterThanIsOperatorScope() {
GreaterThanIsOperator = OldGreaterThanIsOperator;
}
};
/// \brief RAII object that makes sure paren/bracket/brace count is correct
/// after declaration/statement parsing, even when there's a parsing error.
class ParenBraceBracketBalancer {
Parser &P;
unsigned short ParenCount, BracketCount, BraceCount;
public:
ParenBraceBracketBalancer(Parser &p)
: P(p), ParenCount(p.ParenCount), BracketCount(p.BracketCount),
BraceCount(p.BraceCount) { }
~ParenBraceBracketBalancer() {
P.ParenCount = ParenCount;
P.BracketCount = BracketCount;
P.BraceCount = BraceCount;
}
};
} // end namespace clang
#endif