minix/external/bsd/llvm/dist/clang/lib/ASTMatchers/Dynamic/Parser.cpp

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//===--- Parser.cpp - Matcher expression parser -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Recursive parser implementation for the matcher expression grammar.
///
//===----------------------------------------------------------------------===//
#include <string>
#include <vector>
#include "clang/ASTMatchers/Dynamic/Parser.h"
#include "clang/ASTMatchers/Dynamic/Registry.h"
#include "clang/Basic/CharInfo.h"
#include "llvm/ADT/Twine.h"
namespace clang {
namespace ast_matchers {
namespace dynamic {
/// \brief Simple structure to hold information for one token from the parser.
struct Parser::TokenInfo {
/// \brief Different possible tokens.
enum TokenKind {
TK_Eof = 0,
TK_OpenParen = 1,
TK_CloseParen = 2,
TK_Comma = 3,
TK_Period = 4,
TK_Literal = 5,
TK_Ident = 6,
TK_InvalidChar = 7,
TK_Error = 8
};
/// \brief Some known identifiers.
static const char* const ID_Bind;
TokenInfo() : Text(), Kind(TK_Eof), Range(), Value() {}
StringRef Text;
TokenKind Kind;
SourceRange Range;
VariantValue Value;
};
const char* const Parser::TokenInfo::ID_Bind = "bind";
/// \brief Simple tokenizer for the parser.
class Parser::CodeTokenizer {
public:
explicit CodeTokenizer(StringRef MatcherCode, Diagnostics *Error)
: Code(MatcherCode), StartOfLine(MatcherCode), Line(1), Error(Error) {
NextToken = getNextToken();
}
/// \brief Returns but doesn't consume the next token.
const TokenInfo &peekNextToken() const { return NextToken; }
/// \brief Consumes and returns the next token.
TokenInfo consumeNextToken() {
TokenInfo ThisToken = NextToken;
NextToken = getNextToken();
return ThisToken;
}
TokenInfo::TokenKind nextTokenKind() const { return NextToken.Kind; }
private:
TokenInfo getNextToken() {
consumeWhitespace();
TokenInfo Result;
Result.Range.Start = currentLocation();
if (Code.empty()) {
Result.Kind = TokenInfo::TK_Eof;
Result.Text = "";
return Result;
}
switch (Code[0]) {
case ',':
Result.Kind = TokenInfo::TK_Comma;
Result.Text = Code.substr(0, 1);
Code = Code.drop_front();
break;
case '.':
Result.Kind = TokenInfo::TK_Period;
Result.Text = Code.substr(0, 1);
Code = Code.drop_front();
break;
case '(':
Result.Kind = TokenInfo::TK_OpenParen;
Result.Text = Code.substr(0, 1);
Code = Code.drop_front();
break;
case ')':
Result.Kind = TokenInfo::TK_CloseParen;
Result.Text = Code.substr(0, 1);
Code = Code.drop_front();
break;
case '"':
case '\'':
// Parse a string literal.
consumeStringLiteral(&Result);
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
// Parse an unsigned literal.
consumeUnsignedLiteral(&Result);
break;
default:
if (isAlphanumeric(Code[0])) {
// Parse an identifier
size_t TokenLength = 1;
while (TokenLength < Code.size() && isAlphanumeric(Code[TokenLength]))
++TokenLength;
Result.Kind = TokenInfo::TK_Ident;
Result.Text = Code.substr(0, TokenLength);
Code = Code.drop_front(TokenLength);
} else {
Result.Kind = TokenInfo::TK_InvalidChar;
Result.Text = Code.substr(0, 1);
Code = Code.drop_front(1);
}
break;
}
Result.Range.End = currentLocation();
return Result;
}
/// \brief Consume an unsigned literal.
void consumeUnsignedLiteral(TokenInfo *Result) {
unsigned Length = 1;
if (Code.size() > 1) {
// Consume the 'x' or 'b' radix modifier, if present.
switch (toLowercase(Code[1])) {
case 'x': case 'b': Length = 2;
}
}
while (Length < Code.size() && isHexDigit(Code[Length]))
++Length;
Result->Text = Code.substr(0, Length);
Code = Code.drop_front(Length);
unsigned Value;
if (!Result->Text.getAsInteger(0, Value)) {
Result->Kind = TokenInfo::TK_Literal;
Result->Value = Value;
} else {
SourceRange Range;
Range.Start = Result->Range.Start;
Range.End = currentLocation();
Error->addError(Range, Error->ET_ParserUnsignedError) << Result->Text;
Result->Kind = TokenInfo::TK_Error;
}
}
/// \brief Consume a string literal.
///
/// \c Code must be positioned at the start of the literal (the opening
/// quote). Consumed until it finds the same closing quote character.
void consumeStringLiteral(TokenInfo *Result) {
bool InEscape = false;
const char Marker = Code[0];
for (size_t Length = 1, Size = Code.size(); Length != Size; ++Length) {
if (InEscape) {
InEscape = false;
continue;
}
if (Code[Length] == '\\') {
InEscape = true;
continue;
}
if (Code[Length] == Marker) {
Result->Kind = TokenInfo::TK_Literal;
Result->Text = Code.substr(0, Length + 1);
Result->Value = Code.substr(1, Length - 1).str();
Code = Code.drop_front(Length + 1);
return;
}
}
StringRef ErrorText = Code;
Code = Code.drop_front(Code.size());
SourceRange Range;
Range.Start = Result->Range.Start;
Range.End = currentLocation();
Error->addError(Range, Error->ET_ParserStringError) << ErrorText;
Result->Kind = TokenInfo::TK_Error;
}
/// \brief Consume all leading whitespace from \c Code.
void consumeWhitespace() {
while (!Code.empty() && isWhitespace(Code[0])) {
if (Code[0] == '\n') {
++Line;
StartOfLine = Code.drop_front();
}
Code = Code.drop_front();
}
}
SourceLocation currentLocation() {
SourceLocation Location;
Location.Line = Line;
Location.Column = Code.data() - StartOfLine.data() + 1;
return Location;
}
StringRef Code;
StringRef StartOfLine;
unsigned Line;
Diagnostics *Error;
TokenInfo NextToken;
};
Parser::Sema::~Sema() {}
/// \brief Parse and validate a matcher expression.
/// \return \c true on success, in which case \c Value has the matcher parsed.
/// If the input is malformed, or some argument has an error, it
/// returns \c false.
bool Parser::parseMatcherExpressionImpl(VariantValue *Value) {
const TokenInfo NameToken = Tokenizer->consumeNextToken();
assert(NameToken.Kind == TokenInfo::TK_Ident);
const TokenInfo OpenToken = Tokenizer->consumeNextToken();
if (OpenToken.Kind != TokenInfo::TK_OpenParen) {
Error->addError(OpenToken.Range, Error->ET_ParserNoOpenParen)
<< OpenToken.Text;
return false;
}
std::vector<ParserValue> Args;
TokenInfo EndToken;
while (Tokenizer->nextTokenKind() != TokenInfo::TK_Eof) {
if (Tokenizer->nextTokenKind() == TokenInfo::TK_CloseParen) {
// End of args.
EndToken = Tokenizer->consumeNextToken();
break;
}
if (Args.size() > 0) {
// We must find a , token to continue.
const TokenInfo CommaToken = Tokenizer->consumeNextToken();
if (CommaToken.Kind != TokenInfo::TK_Comma) {
Error->addError(CommaToken.Range, Error->ET_ParserNoComma)
<< CommaToken.Text;
return false;
}
}
Diagnostics::Context Ctx(Diagnostics::Context::MatcherArg, Error,
NameToken.Text, NameToken.Range, Args.size() + 1);
ParserValue ArgValue;
ArgValue.Text = Tokenizer->peekNextToken().Text;
ArgValue.Range = Tokenizer->peekNextToken().Range;
if (!parseExpressionImpl(&ArgValue.Value)) return false;
Args.push_back(ArgValue);
}
if (EndToken.Kind == TokenInfo::TK_Eof) {
Error->addError(OpenToken.Range, Error->ET_ParserNoCloseParen);
return false;
}
std::string BindID;
if (Tokenizer->peekNextToken().Kind == TokenInfo::TK_Period) {
// Parse .bind("foo")
Tokenizer->consumeNextToken(); // consume the period.
const TokenInfo BindToken = Tokenizer->consumeNextToken();
const TokenInfo OpenToken = Tokenizer->consumeNextToken();
const TokenInfo IDToken = Tokenizer->consumeNextToken();
const TokenInfo CloseToken = Tokenizer->consumeNextToken();
// TODO: We could use different error codes for each/some to be more
// explicit about the syntax error.
if (BindToken.Kind != TokenInfo::TK_Ident ||
BindToken.Text != TokenInfo::ID_Bind) {
Error->addError(BindToken.Range, Error->ET_ParserMalformedBindExpr);
return false;
}
if (OpenToken.Kind != TokenInfo::TK_OpenParen) {
Error->addError(OpenToken.Range, Error->ET_ParserMalformedBindExpr);
return false;
}
if (IDToken.Kind != TokenInfo::TK_Literal || !IDToken.Value.isString()) {
Error->addError(IDToken.Range, Error->ET_ParserMalformedBindExpr);
return false;
}
if (CloseToken.Kind != TokenInfo::TK_CloseParen) {
Error->addError(CloseToken.Range, Error->ET_ParserMalformedBindExpr);
return false;
}
BindID = IDToken.Value.getString();
}
// Merge the start and end infos.
Diagnostics::Context Ctx(Diagnostics::Context::ConstructMatcher, Error,
NameToken.Text, NameToken.Range);
SourceRange MatcherRange = NameToken.Range;
MatcherRange.End = EndToken.Range.End;
VariantMatcher Result = S->actOnMatcherExpression(
NameToken.Text, MatcherRange, BindID, Args, Error);
if (Result.isNull()) return false;
*Value = Result;
return true;
}
/// \brief Parse an <Expresssion>
bool Parser::parseExpressionImpl(VariantValue *Value) {
switch (Tokenizer->nextTokenKind()) {
case TokenInfo::TK_Literal:
*Value = Tokenizer->consumeNextToken().Value;
return true;
case TokenInfo::TK_Ident:
return parseMatcherExpressionImpl(Value);
case TokenInfo::TK_Eof:
Error->addError(Tokenizer->consumeNextToken().Range,
Error->ET_ParserNoCode);
return false;
case TokenInfo::TK_Error:
// This error was already reported by the tokenizer.
return false;
case TokenInfo::TK_OpenParen:
case TokenInfo::TK_CloseParen:
case TokenInfo::TK_Comma:
case TokenInfo::TK_Period:
case TokenInfo::TK_InvalidChar:
const TokenInfo Token = Tokenizer->consumeNextToken();
Error->addError(Token.Range, Error->ET_ParserInvalidToken) << Token.Text;
return false;
}
llvm_unreachable("Unknown token kind.");
}
Parser::Parser(CodeTokenizer *Tokenizer, Sema *S,
Diagnostics *Error)
: Tokenizer(Tokenizer), S(S), Error(Error) {}
class RegistrySema : public Parser::Sema {
public:
virtual ~RegistrySema() {}
VariantMatcher actOnMatcherExpression(StringRef MatcherName,
const SourceRange &NameRange,
StringRef BindID,
ArrayRef<ParserValue> Args,
Diagnostics *Error) {
if (BindID.empty()) {
return Registry::constructMatcher(MatcherName, NameRange, Args, Error);
} else {
return Registry::constructBoundMatcher(MatcherName, NameRange, BindID,
Args, Error);
}
}
};
bool Parser::parseExpression(StringRef Code, VariantValue *Value,
Diagnostics *Error) {
RegistrySema S;
return parseExpression(Code, &S, Value, Error);
}
bool Parser::parseExpression(StringRef Code, Sema *S,
VariantValue *Value, Diagnostics *Error) {
CodeTokenizer Tokenizer(Code, Error);
if (!Parser(&Tokenizer, S, Error).parseExpressionImpl(Value)) return false;
if (Tokenizer.peekNextToken().Kind != TokenInfo::TK_Eof) {
Error->addError(Tokenizer.peekNextToken().Range,
Error->ET_ParserTrailingCode);
return false;
}
return true;
}
llvm::Optional<DynTypedMatcher>
Parser::parseMatcherExpression(StringRef Code, Diagnostics *Error) {
RegistrySema S;
return parseMatcherExpression(Code, &S, Error);
}
llvm::Optional<DynTypedMatcher>
Parser::parseMatcherExpression(StringRef Code, Parser::Sema *S,
Diagnostics *Error) {
VariantValue Value;
if (!parseExpression(Code, S, &Value, Error))
return llvm::Optional<DynTypedMatcher>();
if (!Value.isMatcher()) {
Error->addError(SourceRange(), Error->ET_ParserNotAMatcher);
return llvm::Optional<DynTypedMatcher>();
}
llvm::Optional<DynTypedMatcher> Result =
Value.getMatcher().getSingleMatcher();
if (!Result.hasValue()) {
Error->addError(SourceRange(), Error->ET_ParserOverloadedType)
<< Value.getTypeAsString();
}
return Result;
}
} // namespace dynamic
} // namespace ast_matchers
} // namespace clang