Files
swift-mirror/lib/Parse/Parser.cpp
Dmitri Hrybenko ca5351e4b6 Fix bad recovery in Parser::parseList() and Parser::parseDeclUnionElement()
Now parseList() always sets RBLoc, which fixes the crash.
parseDeclUnionElement() now skips to the next decl, instead of ":", which may
not appear in the file at all.


Swift SVN r7117
2013-08-10 00:44:09 +00:00

491 lines
16 KiB
C++

//===--- Parser.cpp - Swift Language Parser -------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements the Swift parser.
//
//===----------------------------------------------------------------------===//
#include "swift/Parse/Parser.h"
#include "swift/Subsystems.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/Diagnostics.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/Basic/SourceManager.h"
#include "swift/Parse/Lexer.h"
#include "swift/Parse/CodeCompletionCallbacks.h"
#include "swift/Parse/DelayedParsingCallbacks.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/SaveAndRestore.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/Twine.h"
using namespace swift;
void DelayedParsingCallbacks::anchor() { }
namespace {
/// To assist debugging parser crashes, tell us the location of the
/// current token.
class PrettyStackTraceParser : public llvm::PrettyStackTraceEntry {
Parser &P;
public:
PrettyStackTraceParser(Parser &P) : P(P) {}
void print(llvm::raw_ostream &out) const {
out << "With parser at source location: ";
printSourceLoc(out, P.Tok.getLoc(), P.Context);
out << '\n';
}
};
/// A visitor that does delayed parsing of function bodies.
class ParseDelayedFunctionBodies : public ASTWalker {
TranslationUnit *TU;
PersistentParserState &ParserState;
CodeCompletionCallbacksFactory *CodeCompletionFactory;
public:
ParseDelayedFunctionBodies(TranslationUnit *TU,
PersistentParserState &ParserState,
CodeCompletionCallbacksFactory *CodeCompletionFactory)
: TU(TU), ParserState(ParserState),
CodeCompletionFactory(CodeCompletionFactory) {}
virtual bool walkToDeclPre(Decl *D) {
if (auto FD = dyn_cast<FuncDecl>(D)) {
if (auto FE = FD->getBody()) {
if (FE->getBodyKind() != FuncExpr::BodyKind::Unparsed)
return false;
parseFunctionBody(FD);
}
return true;
}
return true;
}
private:
void parseFunctionBody(FuncDecl *FD) {
auto FE = FD->getBody();
assert(FE);
assert(FE->getBodyKind() == FuncExpr::BodyKind::Unparsed);
int BufferID = TU->Ctx.SourceMgr.findBufferContainingLoc(FD->getLoc());
Parser TheParser(BufferID, TU, nullptr, &ParserState);
std::unique_ptr<CodeCompletionCallbacks> CodeCompletion;
if (CodeCompletionFactory) {
CodeCompletion.reset(
CodeCompletionFactory->createCodeCompletionCallbacks(TheParser));
TheParser.setCodeCompletionCallbacks(CodeCompletion.get());
}
TheParser.parseDeclFuncBodyDelayed(FD);
CodeCompletion->doneParsing();
}
};
void parseDelayedTopLevelDecl(
TranslationUnit *TU,
PersistentParserState &ParserState,
CodeCompletionCallbacksFactory *CodeCompletionFactory) {
assert(CodeCompletionFactory &&
"delayed parsing of decls only makes sense for code completion");
if (!ParserState.hasDelayedDecl())
return;
int BufferID = TU->Ctx.SourceMgr
.findBufferContainingLoc(ParserState.getDelayedDeclLoc());
Parser TheParser(BufferID, TU, nullptr, &ParserState);
std::unique_ptr<CodeCompletionCallbacks> CodeCompletion(
CodeCompletionFactory->createCodeCompletionCallbacks(TheParser));
TheParser.setCodeCompletionCallbacks(CodeCompletion.get());
TheParser.parseTopLevelCodeDeclDelayed();
CodeCompletion->doneParsing();
}
} // unnamed namespace
/// parseIntoTranslationUnit - Entrypoint for the parser.
bool swift::parseIntoTranslationUnit(TranslationUnit *TU,
unsigned BufferID,
bool *Done,
SILParserState *SIL,
PersistentParserState *PersistentState,
DelayedParsingCallbacks *DelayedParseCB) {
Parser P(BufferID, TU, SIL, PersistentState);
PrettyStackTraceParser StackTrace(P);
if (DelayedParseCB)
P.setDelayedParsingCallbacks(DelayedParseCB);
bool FoundSideEffects = P.parseTranslationUnit(TU);
*Done = P.Tok.is(tok::eof);
return FoundSideEffects;
}
void swift::performDelayedParsing(
TranslationUnit *TU, PersistentParserState &PersistentState,
CodeCompletionCallbacksFactory *CodeCompletionFactory) {
ParseDelayedFunctionBodies Walker(TU, PersistentState,
CodeCompletionFactory);
for (Decl *D : TU->Decls) {
D->walk(Walker);
}
if (CodeCompletionFactory)
parseDelayedTopLevelDecl(TU, PersistentState, CodeCompletionFactory);
}
/// \brief Tokenizes a string literal, taking into account string interpolation.
static void getStringPartTokens(const Token &Tok, SourceManager &SM,
int BufID, const llvm::MemoryBuffer *Buffer,
std::vector<Token> &Toks) {
assert(Tok.is(tok::string_literal));
SmallVector<Lexer::StringSegment, 4> Segments;
Lexer::getStringLiteralSegments(Tok, Segments, /*Diags=*/0);
for (unsigned i = 0, e = Segments.size(); i != e; ++i) {
Lexer::StringSegment &Seg = Segments[i];
bool isFirst = i == 0;
bool isLast = i == e-1;
if (Seg.Kind == Lexer::StringSegment::Literal) {
SourceLoc Loc = Seg.Loc;
unsigned Len = Seg.Length;
if (isFirst) {
// Include the quote.
Loc = Loc.getAdvancedLoc(-1);
++Len;
}
if (isLast) {
// Include the quote.
++Len;
}
StringRef Text(Buffer->getBufferStart() +
SM.getLocOffsetInBuffer(Loc, BufID),
Len);
Token NewTok;
NewTok.setToken(tok::string_literal, Text);
Toks.push_back(NewTok);
} else {
unsigned Offset = SM.getLocOffsetInBuffer(Seg.Loc, BufID);
unsigned EndOffset = Offset + Seg.Length;
std::vector<Token> NewTokens = swift::tokenize(SM, BufID, Offset,
EndOffset,
/*KeepComments=*/true);
Toks.insert(Toks.end(), NewTokens.begin(), NewTokens.end());
}
}
}
std::vector<Token> swift::tokenize(SourceManager &SM, unsigned BufferID,
unsigned Offset, unsigned EndOffset,
bool KeepComments,
bool TokenizeInterpolatedString) {
auto *Buffer = SM->getMemoryBuffer(BufferID);
if (Offset == 0 && EndOffset == 0)
EndOffset = Buffer->getBufferSize();
Lexer L(SM, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false, KeepComments,
Offset, EndOffset);
std::vector<Token> Tokens;
do {
Tokens.emplace_back();
L.lex(Tokens.back());
if (Tokens.back().is(tok::string_literal) && TokenizeInterpolatedString) {
Token StrTok = Tokens.back();
Tokens.pop_back();
getStringPartTokens(StrTok, SM, BufferID, Buffer, Tokens);
}
} while (Tokens.back().isNot(tok::eof));
Tokens.pop_back(); // Remove EOF.
return Tokens;
}
//===----------------------------------------------------------------------===//
// Setup and Helper Methods
//===----------------------------------------------------------------------===//
Parser::Parser(unsigned BufferID, TranslationUnit *TU, SILParserState *SIL,
PersistentParserState *PersistentState)
: SourceMgr(TU->getASTContext().SourceMgr),
BufferID(BufferID),
Diags(TU->getASTContext().Diags),
TU(TU),
L(new Lexer(TU->getASTContext().SourceMgr, BufferID,
&TU->getASTContext().Diags,
/*InSILMode=*/SIL != nullptr, /*KeepComments=*/false)),
SIL(SIL),
Component(TU->getComponent()),
Context(TU->getASTContext()) {
State = PersistentState;
if (!State) {
OwnedState.reset(new PersistentParserState());
State = OwnedState.get();
}
// Set the token to a sentinel so that we know the lexer isn't primed yet.
// This cannot be tok::unknown, since that is a token the lexer could produce.
Tok.setKind(tok::NUM_TOKENS);
auto ParserPos = State->takeParserPosition();
if (ParserPos.isValid() &&
SourceMgr.findBufferContainingLoc(ParserPos.Loc) == int(BufferID)) {
auto BeginParserPosition = getParserPosition(ParserPos);
restoreParserPosition(BeginParserPosition);
}
}
Parser::~Parser() {
delete L;
}
/// peekToken - Return the next token that will be installed by consumeToken.
const Token &Parser::peekToken() {
return L->peekNextToken();
}
SourceLoc Parser::consumeToken() {
SourceLoc Loc = Tok.getLoc();
assert(Tok.isNot(tok::eof) && "Lexing past eof!");
L->lex(Tok);
PreviousLoc = Loc;
return Loc;
}
SourceLoc Parser::getEndOfPreviousLoc() {
return Lexer::getLocForEndOfToken(SourceMgr, PreviousLoc);
}
SourceLoc Parser::consumeStartingLess() {
assert(startsWithLess(Tok) && "Token does not start with '<'");
if (Tok.getLength() == 1)
return consumeToken();
// Skip the starting '<' in the existing token.
SourceLoc Loc = Tok.getLoc();
Tok = L->getTokenAt(Loc.getAdvancedLoc(1));
return Loc;
}
SourceLoc Parser::consumeStartingGreater() {
assert(startsWithGreater(Tok) && "Token does not start with '>'");
if (Tok.getLength() == 1)
return consumeToken();
// Skip the starting '>' in the existing token.
SourceLoc Loc = Tok.getLoc();
Tok = L->getTokenAt(Loc.getAdvancedLoc(1));
return Loc;
}
void Parser::skipSingle(bool StopAtCodeComplete) {
switch (Tok.getKind()) {
case tok::l_paren:
consumeToken();
skipUntil(tok::r_paren, StopAtCodeComplete);
consumeIf(tok::r_paren);
break;
case tok::l_brace:
consumeToken();
skipUntil(tok::r_brace, StopAtCodeComplete);
consumeIf(tok::r_brace);
break;
case tok::l_square:
consumeToken();
skipUntil(tok::r_square, StopAtCodeComplete);
consumeIf(tok::r_square);
break;
case tok::code_complete:
if (!StopAtCodeComplete)
consumeToken();
break;
default:
consumeToken();
break;
}
}
void Parser::skipUntil(tok T1, tok T2, bool StopAtCodeComplete) {
// tok::unknown is a sentinel that means "don't skip".
if (T1 == tok::unknown && T2 == tok::unknown) return;
while (Tok.isNot(tok::eof) && Tok.isNot(T1) && Tok.isNot(T2) &&
(!StopAtCodeComplete || Tok.isNot(tok::code_complete)))
skipSingle(StopAtCodeComplete);
}
void Parser::skipUntilAnyOperator() {
while (Tok.isNot(tok::eof) && Tok.isNotAnyOperator())
skipSingle();
}
void Parser::skipUntilDeclRBrace() {
while (Tok.isNot(tok::eof) && Tok.isNot(tok::r_brace) &&
!isStartOfDecl(Tok, peekToken()))
skipSingle();
}
void Parser::skipUntilDeclStmtRBrace(bool StopAtCodeComplete) {
while (Tok.isNot(tok::eof) && Tok.isNot(tok::r_brace) &&
!isStartOfStmt(Tok) &&
!isStartOfDecl(Tok, peekToken()) &&
(!StopAtCodeComplete || Tok.isNot(tok::code_complete))) {
skipSingle(StopAtCodeComplete);
}
}
//===----------------------------------------------------------------------===//
// Primitive Parsing
//===----------------------------------------------------------------------===//
/// parseIdentifier - Consume an identifier (but not an operator) if
/// present and return its name in Result. Otherwise, emit an error and
/// return true.
bool Parser::parseIdentifier(Identifier &Result, SourceLoc &Loc,
const Diagnostic &D) {
switch (Tok.getKind()) {
#define IDENTIFIER_KEYWORD(kw) case tok::kw_##kw:
#include "swift/Parse/Tokens.def"
case tok::identifier:
Result = Context.getIdentifier(Tok.getText());
Loc = Tok.getLoc();
consumeToken();
return false;
default:
Diags.diagnose(Tok.getLoc(), D);
return true;
}
}
/// parseAnyIdentifier - Consume an identifier or operator if present and return
/// its name in Result. Otherwise, emit an error and return true.
bool Parser::parseAnyIdentifier(Identifier &Result, SourceLoc &Loc,
const Diagnostic &D) {
if (Tok.is(tok::identifier) || Tok.isAnyOperator()) {
Result = Context.getIdentifier(Tok.getText());
Loc = Tok.getLoc();
consumeToken();
return false;
}
Diags.diagnose(Tok.getLoc(), D);
return true;
}
/// parseToken - The parser expects that 'K' is next in the input. If so, it is
/// consumed and false is returned.
///
/// If the input is malformed, this emits the specified error diagnostic.
bool Parser::parseToken(tok K, SourceLoc &TokLoc, const Diagnostic &D) {
if (Tok.is(K)) {
TokLoc = consumeToken(K);
return false;
}
diagnose(Tok.getLoc(), D);
return true;
}
/// parseMatchingToken - Parse the specified expected token and return its
/// location on success. On failure, emit the specified error diagnostic, and a
/// note at the specified note location.
bool Parser::parseMatchingToken(tok K, SourceLoc &TokLoc, Diag<> ErrorDiag,
SourceLoc OtherLoc) {
Diag<> OtherNote;
switch (K) {
case tok::r_paren: OtherNote = diag::opening_paren; break;
case tok::r_square: OtherNote = diag::opening_bracket; break;
case tok::r_brace: OtherNote = diag::opening_brace; break;
default: assert(!"unknown matching token!"); break;
}
if (parseToken(K, TokLoc, ErrorDiag)) {
diagnose(OtherLoc, OtherNote);
return true;
}
return false;
}
/// parseList - Parse the list of statements, expressions, or declarations.
bool Parser::parseList(tok RightK, SourceLoc LeftLoc, SourceLoc &RightLoc,
tok SeparatorK, bool OptionalSep, Diag<> ErrorDiag,
std::function<bool()> callback) {
assert(SeparatorK == tok::comma || SeparatorK == tok::semi);
if (Tok.is(RightK)) {
RightLoc = consumeToken(RightK);
return false;
}
bool Invalid = false;
while (true) {
while (Tok.is(SeparatorK)) {
diagnose(Tok, diag::unexpected_separator,
SeparatorK == tok::comma ? "," : ";")
.fixItRemove(SourceRange(Tok.getLoc()));
consumeToken();
}
SourceLoc StartLoc = Tok.getLoc();
Invalid |= callback();
if (Tok.is(RightK))
break;
// If the lexer stopped with an EOF token whose spelling is ")", then this
// is actually the tuple that is a string literal interpolation context.
// Just accept the ")" and build the tuple as we usually do.
if (Tok.is(tok::eof) && Tok.getText() == ")") {
RightLoc = Tok.getLoc();
return Invalid;
}
if (consumeIf(SeparatorK))
continue;
if (!OptionalSep) {
SourceLoc InsertLoc = Lexer::getLocForEndOfToken(SourceMgr, PreviousLoc);
StringRef Separator = (SeparatorK == tok::comma ? "," : ";");
diagnose(Tok, diag::expected_separator, Separator)
.fixItInsert(InsertLoc, Separator);
Invalid = true;
}
// If we haven't made progress, skip ahead
if (Tok.getLoc() == StartLoc) {
skipUntil(RightK, SeparatorK);
if (Tok.is(RightK))
break;
if (Tok.is(tok::eof) || Tok.is(tok::code_complete)) {
RightLoc = Tok.getLoc();
return true;
}
consumeIf(SeparatorK);
}
}
if (parseMatchingToken(RightK, RightLoc, ErrorDiag, LeftLoc)) {
Invalid = true;
RightLoc = Tok.getLoc();
}
return Invalid;
}
/// diagnoseRedefinition - Diagnose a redefinition error, with a note
/// referring back to the original definition.
void Parser::diagnoseRedefinition(ValueDecl *Prev, ValueDecl *New) {
assert(New != Prev && "Cannot conflict with self");
diagnose(New->getLoc(), diag::decl_redefinition, New->isDefinition());
diagnose(Prev->getLoc(), diag::previous_decldef, Prev->isDefinition(),
Prev->getName());
}