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Parser.cpp
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//===--- Parser.cpp - Swift Language Parser -------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://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/DiagnosticsParse.h"
#include "swift/AST/Module.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/Basic/Defer.h"
#include "swift/Basic/SourceManager.h"
#include "swift/Basic/Timer.h"
#include "swift/Parse/Lexer.h"
#include "swift/Parse/CodeCompletionCallbacks.h"
#include "swift/Parse/DelayedParsingCallbacks.h"
#include "swift/Parse/ParseSILSupport.h"
#include "swift/Parse/SyntaxParsingContext.h"
#include "swift/Syntax/RawSyntax.h"
#include "swift/Syntax/TokenSyntax.h"
#include "llvm/Support/Compiler.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"
static void getStringPartTokens(const swift::Token &Tok,
const swift::LangOptions &LangOpts,
const swift::SourceManager &SM, int BufID,
std::vector<swift::Token> &Toks);
namespace swift {
template <typename DF>
void tokenize(const LangOptions &LangOpts, const SourceManager &SM,
unsigned BufferID, unsigned Offset, unsigned EndOffset,
DiagnosticEngine * Diags,
CommentRetentionMode RetainComments,
TriviaRetentionMode TriviaRetention,
bool TokenizeInterpolatedString, ArrayRef<Token> SplitTokens,
DF &&DestFunc) {
assert((TriviaRetention != TriviaRetentionMode::WithTrivia ||
!TokenizeInterpolatedString) &&
"string interpolation with trivia is not implemented yet");
if (Offset == 0 && EndOffset == 0)
EndOffset = SM.getRangeForBuffer(BufferID).getByteLength();
Lexer L(LangOpts, SM, BufferID, Diags, /*InSILMode=*/false,
HashbangMode::Allowed, RetainComments, TriviaRetention, Offset,
EndOffset);
auto TokComp = [&](const Token &A, const Token &B) {
return SM.isBeforeInBuffer(A.getLoc(), B.getLoc());
};
std::set<Token, decltype(TokComp)> ResetTokens(TokComp);
for (auto C = SplitTokens.begin(), E = SplitTokens.end(); C != E; ++C) {
ResetTokens.insert(*C);
}
Token Tok;
syntax::Trivia LeadingTrivia, TrailingTrivia;
do {
L.lex(Tok, LeadingTrivia, TrailingTrivia);
// If the token has the same location as a reset location,
// reset the token stream
auto F = ResetTokens.find(Tok);
if (F != ResetTokens.end()) {
assert(F->isNot(tok::string_literal));
DestFunc(*F, syntax::Trivia(), syntax::Trivia());
auto NewState = L.getStateForBeginningOfTokenLoc(
F->getLoc().getAdvancedLoc(F->getLength()));
L.restoreState(NewState);
continue;
}
if (Tok.is(tok::string_literal) && TokenizeInterpolatedString) {
std::vector<Token> StrTokens;
getStringPartTokens(Tok, LangOpts, SM, BufferID, StrTokens);
for (auto &StrTok : StrTokens) {
DestFunc(StrTok, syntax::Trivia(), syntax::Trivia());
}
} else {
DestFunc(Tok, LeadingTrivia, TrailingTrivia);
}
} while (Tok.getKind() != tok::eof);
}
} // namespace swift
using namespace swift;
using namespace swift::syntax;
void DelayedParsingCallbacks::anchor() { }
void SILParserTUStateBase::anchor() { }
namespace {
/// A visitor that does delayed parsing of function bodies.
class ParseDelayedFunctionBodies : public ASTWalker {
PersistentParserState &ParserState;
CodeCompletionCallbacksFactory *CodeCompletionFactory;
public:
ParseDelayedFunctionBodies(PersistentParserState &ParserState,
CodeCompletionCallbacksFactory *Factory)
: ParserState(ParserState), CodeCompletionFactory(Factory) {}
bool walkToDeclPre(Decl *D) override {
if (auto AFD = dyn_cast<AbstractFunctionDecl>(D)) {
if (AFD->getBodyKind() != FuncDecl::BodyKind::Unparsed)
return false;
parseFunctionBody(AFD);
return true;
}
return true;
}
private:
void parseFunctionBody(AbstractFunctionDecl *AFD) {
assert(AFD->getBodyKind() == FuncDecl::BodyKind::Unparsed);
SourceFile &SF = *AFD->getDeclContext()->getParentSourceFile();
SourceManager &SourceMgr = SF.getASTContext().SourceMgr;
unsigned BufferID = SourceMgr.findBufferContainingLoc(AFD->getLoc());
Parser TheParser(BufferID, SF, nullptr, &ParserState);
TheParser.SyntaxContext->disable();
std::unique_ptr<CodeCompletionCallbacks> CodeCompletion;
if (CodeCompletionFactory) {
CodeCompletion.reset(
CodeCompletionFactory->createCodeCompletionCallbacks(TheParser));
TheParser.setCodeCompletionCallbacks(CodeCompletion.get());
}
if (ParserState.hasFunctionBodyState(AFD))
TheParser.parseAbstractFunctionBodyDelayed(AFD);
if (CodeCompletion)
CodeCompletion->doneParsing();
}
};
static void parseDelayedDecl(
PersistentParserState &ParserState,
CodeCompletionCallbacksFactory *CodeCompletionFactory) {
if (!ParserState.hasDelayedDecl())
return;
SourceFile &SF = *ParserState.getDelayedDeclContext()->getParentSourceFile();
SourceManager &SourceMgr = SF.getASTContext().SourceMgr;
unsigned BufferID =
SourceMgr.findBufferContainingLoc(ParserState.getDelayedDeclLoc());
Parser TheParser(BufferID, SF, nullptr, &ParserState);
// Disable libSyntax creation in the delayed parsing.
TheParser.SyntaxContext->disable();
std::unique_ptr<CodeCompletionCallbacks> CodeCompletion;
if (CodeCompletionFactory) {
CodeCompletion.reset(
CodeCompletionFactory->createCodeCompletionCallbacks(TheParser));
TheParser.setCodeCompletionCallbacks(CodeCompletion.get());
}
switch (ParserState.getDelayedDeclKind()) {
case PersistentParserState::DelayedDeclKind::TopLevelCodeDecl:
TheParser.parseTopLevelCodeDeclDelayed();
break;
case PersistentParserState::DelayedDeclKind::Decl:
TheParser.parseDeclDelayed();
break;
}
if (CodeCompletion)
CodeCompletion->doneParsing();
}
} // unnamed namespace
swift::Parser::BacktrackingScope::~BacktrackingScope() {
if (Backtrack) {
P.backtrackToPosition(PP);
DT.abort();
}
}
void swift::performDelayedParsing(
DeclContext *DC, PersistentParserState &PersistentState,
CodeCompletionCallbacksFactory *CodeCompletionFactory) {
SharedTimer timer("Parsing");
ParseDelayedFunctionBodies Walker(PersistentState,
CodeCompletionFactory);
DC->walkContext(Walker);
if (CodeCompletionFactory)
parseDelayedDecl(PersistentState, CodeCompletionFactory);
}
/// \brief Tokenizes a string literal, taking into account string interpolation.
static void getStringPartTokens(const Token &Tok, const LangOptions &LangOpts,
const SourceManager &SM,
int BufID, std::vector<Token> &Toks) {
assert(Tok.is(tok::string_literal));
bool IsMultiline = Tok.isMultilineString();
unsigned CustomDelimiterLen = Tok.getCustomDelimiterLen();
unsigned QuoteLen = (IsMultiline ? 3 : 1) + CustomDelimiterLen;
SmallVector<Lexer::StringSegment, 4> Segments;
Lexer::getStringLiteralSegments(Tok, Segments, /*Diags=*/nullptr);
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(-QuoteLen);
Len += QuoteLen;
}
if (isLast) {
// Include the quote.
Len += QuoteLen;
}
StringRef Text = SM.extractText({ Loc, Len });
Token NewTok;
NewTok.setToken(tok::string_literal, Text,
IsMultiline, CustomDelimiterLen);
Toks.push_back(NewTok);
} else {
assert(Seg.Kind == Lexer::StringSegment::Expr &&
"new enumerator was introduced ?");
unsigned Offset = SM.getLocOffsetInBuffer(Seg.Loc, BufID);
unsigned EndOffset = Offset + Seg.Length;
if (isFirst) {
// Add a token for the quote character.
StringRef Text = SM.extractText({ Seg.Loc.getAdvancedLoc(-2), 1 });
Token NewTok;
NewTok.setToken(tok::string_literal, Text);
Toks.push_back(NewTok);
}
std::vector<Token> NewTokens = swift::tokenize(LangOpts, SM, BufID,
Offset, EndOffset,
/*Diags=*/nullptr,
/*KeepComments=*/true);
Toks.insert(Toks.end(), NewTokens.begin(), NewTokens.end());
if (isLast) {
// Add a token for the quote character.
StringRef Text = SM.extractText({ Seg.Loc.getAdvancedLoc(Seg.Length),
1 });
Token NewTok;
NewTok.setToken(tok::string_literal, Text);
Toks.push_back(NewTok);
}
}
}
}
std::vector<Token> swift::tokenize(const LangOptions &LangOpts,
const SourceManager &SM, unsigned BufferID,
unsigned Offset, unsigned EndOffset,
DiagnosticEngine *Diags,
bool KeepComments,
bool TokenizeInterpolatedString,
ArrayRef<Token> SplitTokens) {
std::vector<Token> Tokens;
tokenize(LangOpts, SM, BufferID, Offset, EndOffset,
Diags,
KeepComments ? CommentRetentionMode::ReturnAsTokens
: CommentRetentionMode::AttachToNextToken,
TriviaRetentionMode::WithoutTrivia, TokenizeInterpolatedString,
SplitTokens,
[&](const Token &Tok, const Trivia &LeadingTrivia,
const Trivia &TrailingTrivia) { Tokens.push_back(Tok); });
assert(Tokens.back().is(tok::eof));
Tokens.pop_back(); // Remove EOF.
return Tokens;
}
std::vector<std::pair<RC<syntax::RawSyntax>, syntax::AbsolutePosition>>
swift::tokenizeWithTrivia(const LangOptions &LangOpts, const SourceManager &SM,
unsigned BufferID, unsigned Offset,
unsigned EndOffset,
DiagnosticEngine *Diags) {
std::vector<std::pair<RC<syntax::RawSyntax>, syntax::AbsolutePosition>>
Tokens;
syntax::AbsolutePosition RunningPos;
tokenize(
LangOpts, SM, BufferID, Offset, EndOffset, Diags,
CommentRetentionMode::AttachToNextToken, TriviaRetentionMode::WithTrivia,
/*TokenizeInterpolatedString=*/false,
/*SplitTokens=*/ArrayRef<Token>(),
[&](const Token &Tok, const Trivia &LeadingTrivia,
const Trivia &TrailingTrivia) {
auto Text = OwnedString::makeRefCounted(Tok.getText());
auto ThisToken =
RawSyntax::make(Tok.getKind(), Text, LeadingTrivia.Pieces,
TrailingTrivia.Pieces, SourcePresence::Present);
auto ThisTokenPos = ThisToken->accumulateAbsolutePosition(RunningPos);
Tokens.push_back({ThisToken, ThisTokenPos.getValue()});
});
return Tokens;
}
//===----------------------------------------------------------------------===//
// Setup and Helper Methods
//===----------------------------------------------------------------------===//
Parser::Parser(unsigned BufferID, SourceFile &SF, SILParserTUStateBase *SIL,
PersistentParserState *PersistentState)
: Parser(
std::unique_ptr<Lexer>(new Lexer(
SF.getASTContext().LangOpts, SF.getASTContext().SourceMgr,
BufferID, &SF.getASTContext().Diags,
/*InSILMode=*/SIL != nullptr,
SF.Kind == SourceFileKind::Main
? HashbangMode::Allowed
: HashbangMode::Disallowed,
SF.getASTContext().LangOpts.AttachCommentsToDecls
? CommentRetentionMode::AttachToNextToken
: CommentRetentionMode::None,
SF.shouldBuildSyntaxTree()
? TriviaRetentionMode::WithTrivia
: TriviaRetentionMode::WithoutTrivia)),
SF, SIL, PersistentState) {}
namespace {
/// This is the token receiver that helps SourceFile to keep track of its
/// underlying corrected token stream.
class TokenRecorder: public ConsumeTokenReceiver {
ASTContext &Ctx;
SourceManager &SM;
// Token list ordered by their appearance in the source file.
std::vector<Token> &Bag;
unsigned BufferID;
// Registered token kind change. These changes are regiestered before the
// token is consumed, so we need to keep track of them here.
llvm::DenseMap<const void*, tok> TokenKindChangeMap;
std::vector<Token>::iterator lower_bound(SourceLoc Loc) {
return token_lower_bound(Bag, Loc);
}
std::vector<Token>::iterator lower_bound(Token Tok) {
return lower_bound(Tok.getLoc());
}
void relexComment(CharSourceRange CommentRange,
llvm::SmallVectorImpl<Token> &Scratch) {
Lexer L(Ctx.LangOpts, Ctx.SourceMgr, BufferID, nullptr, /*InSILMode=*/false,
HashbangMode::Disallowed,
CommentRetentionMode::ReturnAsTokens,
TriviaRetentionMode::WithoutTrivia,
SM.getLocOffsetInBuffer(CommentRange.getStart(), BufferID),
SM.getLocOffsetInBuffer(CommentRange.getEnd(), BufferID));
while(true) {
Token Result;
L.lex(Result);
if (Result.is(tok::eof))
break;
assert(Result.is(tok::comment));
Scratch.push_back(Result);
}
}
public:
TokenRecorder(SourceFile &SF):
Ctx(SF.getASTContext()),
SM(SF.getASTContext().SourceMgr),
Bag(SF.getTokenVector()),
BufferID(SF.getBufferID().getValue()) {};
void finalize() override {
// We should consume the comments at the end of the file that don't attach
// to any tokens.
SourceLoc TokEndLoc;
if (!Bag.empty()) {
Token Last = Bag.back();
TokEndLoc = Last.getLoc().getAdvancedLoc(Last.getLength());
} else {
// Special case: the file contains nothing but comments.
TokEndLoc = SM.getLocForBufferStart(BufferID);
}
llvm::SmallVector<Token, 4> Scratch;
relexComment(CharSourceRange(SM, TokEndLoc,
SM.getRangeForBuffer(BufferID).getEnd()),
Scratch);
// Accept these orphaned comments.
Bag.insert(Bag.end(), Scratch.begin(), Scratch.end());
}
void registerTokenKindChange(SourceLoc Loc, tok NewKind) override {
// If a token with the same location is already in the bag, update its kind.
auto Pos = lower_bound(Loc);
if (Pos != Bag.end() && Pos->getLoc().getOpaquePointerValue() ==
Loc.getOpaquePointerValue()) {
Pos->setKind(NewKind);
return;
}
// Save the update for later.
TokenKindChangeMap[Loc.getOpaquePointerValue()] = NewKind;
}
void receive(Token Tok) override {
// We filter out all tokens without valid location
if(Tok.getLoc().isInvalid())
return;
// If a token with the same location is already in the bag, skip this token.
auto Pos = lower_bound(Tok);
if (Pos != Bag.end() && Pos->getLoc().getOpaquePointerValue() ==
Tok.getLoc().getOpaquePointerValue()) {
return;
}
// Update Token kind if a kind update was regiestered before.
auto Found = TokenKindChangeMap.find(Tok.getLoc().
getOpaquePointerValue());
if (Found != TokenKindChangeMap.end()) {
Tok.setKind(Found->getSecond());
}
// If the token has comment attached to it, re-lexing these comments and
// consume them as separate tokens.
llvm::SmallVector<Token, 4> TokensToConsume;
if (Tok.hasComment()) {
relexComment(Tok.getCommentRange(), TokensToConsume);
}
TokensToConsume.push_back(Tok);
Bag.insert(Pos, TokensToConsume.begin(), TokensToConsume.end());
}
};
} // End of an anonymous namespace.
Parser::Parser(std::unique_ptr<Lexer> Lex, SourceFile &SF,
SILParserTUStateBase *SIL,
PersistentParserState *PersistentState)
: SourceMgr(SF.getASTContext().SourceMgr),
Diags(SF.getASTContext().Diags),
SF(SF),
L(Lex.release()),
SIL(SIL),
CurDeclContext(&SF),
Context(SF.getASTContext()),
TokReceiver(SF.shouldCollectToken() ?
new TokenRecorder(SF) :
new ConsumeTokenReceiver()),
SyntaxContext(new SyntaxParsingContext(SyntaxContext, SF,
L->getBufferID())) {
State = PersistentState;
if (!State) {
OwnedState.reset(new PersistentParserState(Context));
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() &&
L->isStateForCurrentBuffer(ParserPos.LS)) {
restoreParserPosition(ParserPos);
InPoundLineEnvironment = State->InPoundLineEnvironment;
}
}
Parser::~Parser() {
delete L;
delete TokReceiver;
delete SyntaxContext;
}
bool Parser::allowTopLevelCode() const {
return SF.isScriptMode();
}
const Token &Parser::peekToken() {
return L->peekNextToken();
}
SourceLoc Parser::consumeTokenWithoutFeedingReceiver() {
SourceLoc Loc = Tok.getLoc();
assert(Tok.isNot(tok::eof) && "Lexing past eof!");
if (IsParsingInterfaceTokens && !Tok.getText().empty()) {
SF.recordInterfaceToken(Tok.getText());
}
L->lex(Tok, LeadingTrivia, TrailingTrivia);
PreviousLoc = Loc;
return Loc;
}
void Parser::consumeExtraToken(Token Extra) {
TokReceiver->receive(Extra);
}
SourceLoc Parser::consumeToken() {
TokReceiver->receive(Tok);
SyntaxContext->addToken(Tok, LeadingTrivia, TrailingTrivia);
return consumeTokenWithoutFeedingReceiver();
}
SourceLoc Parser::getEndOfPreviousLoc() {
return Lexer::getLocForEndOfToken(SourceMgr, PreviousLoc);
}
SourceLoc Parser::consumeStartingCharacterOfCurrentToken(tok Kind, size_t Len) {
// Consumes prefix of token and returns its location.
// (like '?', '<', '>' or '!' immediately followed by '<')
assert(Len >= 1);
// Current token can be either one-character token we want to consume...
if (Tok.getLength() == Len) {
Tok.setKind(Kind);
return consumeToken();
}
auto Loc = Tok.getLoc();
// ... or a multi-character token with the first N characters being the one
// that we want to consume as a separate token.
assert(Tok.getLength() > Len);
markSplitToken(Kind, Tok.getText().substr(0, Len));
auto NewState = L->getStateForBeginningOfTokenLoc(Loc.getAdvancedLoc(Len));
restoreParserPosition(ParserPosition(NewState, Loc),
/*enableDiagnostics=*/true);
return PreviousLoc;
}
void Parser::markSplitToken(tok Kind, StringRef Txt) {
SplitTokens.emplace_back();
SplitTokens.back().setToken(Kind, Txt);
Trivia EmptyTrivia;
SyntaxContext->addToken(SplitTokens.back(), LeadingTrivia, EmptyTrivia);
TokReceiver->receive(SplitTokens.back());
}
SourceLoc Parser::consumeStartingLess() {
assert(startsWithLess(Tok) && "Token does not start with '<'");
return consumeStartingCharacterOfCurrentToken(tok::l_angle);
}
SourceLoc Parser::consumeStartingGreater() {
assert(startsWithGreater(Tok) && "Token does not start with '>'");
return consumeStartingCharacterOfCurrentToken(tok::r_angle);
}
void Parser::skipSingle() {
switch (Tok.getKind()) {
case tok::l_paren:
consumeToken();
skipUntil(tok::r_paren);
consumeIf(tok::r_paren);
break;
case tok::l_brace:
consumeToken();
skipUntil(tok::r_brace);
consumeIf(tok::r_brace);
break;
case tok::l_square:
consumeToken();
skipUntil(tok::r_square);
consumeIf(tok::r_square);
break;
case tok::pound_if:
case tok::pound_else:
case tok::pound_elseif:
consumeToken();
// skipUntil also implicitly stops at tok::pound_endif.
skipUntil(tok::pound_else, tok::pound_elseif);
if (Tok.isAny(tok::pound_else, tok::pound_elseif))
skipSingle();
else
consumeIf(tok::pound_endif);
break;
default:
consumeToken();
break;
}
}
void Parser::skipUntil(tok T1, tok T2) {
// tok::NUM_TOKENS is a sentinel that means "don't skip".
if (T1 == tok::NUM_TOKENS && T2 == tok::NUM_TOKENS) return;
while (Tok.isNot(T1, T2, tok::eof, tok::pound_endif, tok::code_complete))
skipSingle();
}
void Parser::skipUntilAnyOperator() {
while (Tok.isNot(tok::eof, tok::pound_endif, tok::code_complete) &&
Tok.isNotAnyOperator())
skipSingle();
}
/// \brief Skip until a token that starts with '>', and consume it if found.
/// Applies heuristics that are suitable when trying to find the end of a list
/// of generic parameters, generic arguments, or list of types in a protocol
/// composition.
SourceLoc Parser::skipUntilGreaterInTypeList(bool protocolComposition) {
SourceLoc lastLoc = PreviousLoc;
while (true) {
switch (Tok.getKind()) {
case tok::eof:
case tok::l_brace:
case tok::r_brace:
case tok::code_complete:
return lastLoc;
#define KEYWORD(X) case tok::kw_##X:
#define POUND_KEYWORD(X) case tok::pound_##X:
#include "swift/Syntax/TokenKinds.def"
// 'Self' can appear in types, skip it.
if (Tok.is(tok::kw_Self))
break;
if (isStartOfStmt() || isStartOfDecl() || Tok.is(tok::pound_endif))
return lastLoc;
break;
case tok::l_paren:
case tok::r_paren:
case tok::l_square:
case tok::r_square:
// In generic type parameter list, skip '[' ']' '(' ')', because they
// can appear in types.
if (protocolComposition)
return lastLoc;
break;
default:
if (Tok.isAnyOperator() && startsWithGreater(Tok))
return consumeStartingGreater();
break;
}
skipSingle();
lastLoc = PreviousLoc;
}
}
void Parser::skipUntilDeclRBrace() {
while (Tok.isNot(tok::eof, tok::r_brace, tok::pound_endif,
tok::pound_else, tok::pound_elseif,
tok::code_complete) &&
!isStartOfDecl())
skipSingle();
}
void Parser::skipUntilDeclStmtRBrace(tok T1) {
while (Tok.isNot(T1, tok::eof, tok::r_brace, tok::pound_endif,
tok::pound_else, tok::pound_elseif,
tok::code_complete) &&
!isStartOfStmt() && !isStartOfDecl()) {
skipSingle();
}
}
void Parser::skipUntilDeclStmtRBrace(tok T1, tok T2) {
while (Tok.isNot(T1, T2, tok::eof, tok::r_brace, tok::pound_endif,
tok::pound_else, tok::pound_elseif,
tok::code_complete) &&
!isStartOfStmt() && !isStartOfDecl()) {
skipSingle();
}
}
void Parser::skipUntilDeclRBrace(tok T1, tok T2) {
while (Tok.isNot(T1, T2, tok::eof, tok::r_brace, tok::pound_endif,
tok::pound_else, tok::pound_elseif) &&
!isStartOfDecl()) {
skipSingle();
}
}
void Parser::skipUntilConditionalBlockClose() {
while (Tok.isNot(tok::pound_else, tok::pound_elseif, tok::pound_endif,
tok::eof)) {
skipSingle();
}
}
bool Parser::skipUntilTokenOrEndOfLine(tok T1) {
while (Tok.isNot(tok::eof, T1) && !Tok.isAtStartOfLine())
skipSingle();
return Tok.is(T1) && !Tok.isAtStartOfLine();
}
bool Parser::loadCurrentSyntaxNodeFromCache() {
// Don't do a cache lookup when not building a syntax tree since otherwise
// the corresponding AST nodes do not get created
if (!SF.shouldBuildSyntaxTree()) {
return false;
}
unsigned LexerOffset =
SourceMgr.getLocOffsetInBuffer(Tok.getLoc(), L->getBufferID());
unsigned LeadingTriviaOffset = LexerOffset - LeadingTrivia.getTextLength();
if (auto TextLength = SyntaxContext->loadFromCache(LeadingTriviaOffset)) {
L->resetToOffset(LeadingTriviaOffset + TextLength);
L->lex(Tok, LeadingTrivia, TrailingTrivia);
return true;
}
return false;
}
bool Parser::parseEndIfDirective(SourceLoc &Loc) {
Loc = Tok.getLoc();
if (parseToken(tok::pound_endif, diag::expected_close_to_if_directive)) {
Loc = PreviousLoc;
skipUntilConditionalBlockClose();
return true;
} else if (!Tok.isAtStartOfLine() && Tok.isNot(tok::eof))
diagnose(Tok.getLoc(),
diag::extra_tokens_conditional_compilation_directive);
return false;
}
Parser::StructureMarkerRAII::StructureMarkerRAII(Parser &parser,
const Token &tok)
: P(parser)
{
switch (tok.getKind()) {
case tok::l_brace:
P.StructureMarkers.push_back({tok.getLoc(),
StructureMarkerKind::OpenBrace,
None});
break;
case tok::l_paren:
P.StructureMarkers.push_back({tok.getLoc(),
StructureMarkerKind::OpenParen,
None});
break;
case tok::l_square:
P.StructureMarkers.push_back({tok.getLoc(),
StructureMarkerKind::OpenSquare,
None});
break;
default:
llvm_unreachable("Not a matched token");
}
}
void Parser::StructureMarkerRAII::diagnoseOverflow() {
auto Loc = P.StructureMarkers.back().Loc;
P.diagnose(Loc, diag::structure_overflow, MaxDepth);
}
//===----------------------------------------------------------------------===//
// Primitive Parsing
//===----------------------------------------------------------------------===//
bool Parser::parseIdentifier(Identifier &Result, SourceLoc &Loc,
const Diagnostic &D) {
switch (Tok.getKind()) {
case tok::kw_self:
case tok::kw_Self:
case tok::identifier:
Loc = consumeIdentifier(&Result);
return false;
default:
checkForInputIncomplete();
diagnose(Tok, D);
return true;
}
}
bool Parser::parseSpecificIdentifier(StringRef expected, SourceLoc &loc,
const Diagnostic &D) {
if (Tok.getText() != expected) {
diagnose(Tok, D);
return true;
}
loc = consumeToken(tok::identifier);
return false;
}
/// 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;
}
// When we know we're supposed to get an identifier or operator, map the
// postfix '!' to an operator name.
if (Tok.is(tok::exclaim_postfix)) {
Result = Context.getIdentifier(Tok.getText());
Loc = Tok.getLoc();
consumeToken(tok::exclaim_postfix);
return false;
}
checkForInputIncomplete();
if (Tok.isKeyword()) {
diagnose(Tok, diag::keyword_cant_be_identifier, Tok.getText());
diagnose(Tok, diag::backticks_to_escape)
.fixItReplace(Tok.getLoc(), "`" + Tok.getText().str() + "`");
} else {
diagnose(Tok, 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;
}
checkForInputIncomplete();
diagnose(Tok, 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: llvm_unreachable("unknown matching token!"); break;
}
if (parseToken(K, TokLoc, ErrorDiag)) {
diagnose(OtherLoc, OtherNote);
TokLoc = PreviousLoc;
return true;
}
return false;
}
static SyntaxKind getListElementKind(SyntaxKind ListKind) {
switch (ListKind) {
case SyntaxKind::FunctionCallArgumentList:
return SyntaxKind::FunctionCallArgument;
case SyntaxKind::ArrayElementList:
return SyntaxKind::ArrayElement;
case SyntaxKind::DictionaryElementList:
return SyntaxKind::DictionaryElement;
case SyntaxKind::TupleElementList:
return SyntaxKind::TupleElement;
case SyntaxKind::FunctionParameterList:
return SyntaxKind::FunctionParameter;
case SyntaxKind::TupleTypeElementList:
return SyntaxKind::TupleTypeElement;
case SyntaxKind::TuplePatternElementList:
return SyntaxKind::TuplePatternElement;
default:
return SyntaxKind::Unknown;
}
}
ParserStatus
Parser::parseList(tok RightK, SourceLoc LeftLoc, SourceLoc &RightLoc,
bool AllowSepAfterLast, Diag<> ErrorDiag, SyntaxKind Kind,
llvm::function_ref<ParserStatus()> callback) {
llvm::Optional<SyntaxParsingContext> ListContext;
ListContext.emplace(SyntaxContext, Kind);
if (Kind == SyntaxKind::Unknown)
ListContext->setTransparent();
SyntaxKind ElementKind = getListElementKind(Kind);
if (Tok.is(RightK)) {
ListContext.reset();
RightLoc = consumeToken(RightK);
return makeParserSuccess();
}
ParserStatus Status;
while (true) {
while (Tok.is(tok::comma)) {
diagnose(Tok, diag::unexpected_separator, ",")
.fixItRemove(SourceRange(Tok.getLoc()));
consumeToken();
}
SourceLoc StartLoc = Tok.getLoc();
SyntaxParsingContext ElementContext(SyntaxContext, ElementKind);
if (ElementKind == SyntaxKind::Unknown)
ElementContext.setTransparent();
Status |= 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() == ")" && RightK == tok::r_paren) {
RightLoc = Tok.getLoc();
return Status;
}
// If we haven't made progress, or seeing any error, skip ahead.
if (Tok.getLoc() == StartLoc || Status.isError()) {
assert(Status.isError() && "no progress without error");
skipUntilDeclRBrace(RightK, tok::comma);
if (Tok.is(RightK) || Tok.isNot(tok::comma))
break;
}
if (consumeIf(tok::comma)) {
if (Tok.isNot(RightK))
continue;
if (!AllowSepAfterLast) {
diagnose(Tok, diag::unexpected_separator, ",")
.fixItRemove(SourceRange(PreviousLoc));
}
break;
}
// If we're in a comma-separated list, the next token is at the
// beginning of a new line and can never start an element, break.
if (Tok.isAtStartOfLine() &&
(Tok.is(tok::r_brace) || isStartOfDecl() || isStartOfStmt())) {
break;
}
// If we found EOF or such, bailout.
if (Tok.isAny(tok::eof, tok::pound_endif)) {
IsInputIncomplete = true;
break;
}
diagnose(Tok, diag::expected_separator, ",")
.fixItInsertAfter(PreviousLoc, ",");
Status.setIsParseError();
}
ListContext.reset();
if (Status.isError()) {
// If we've already got errors, don't emit missing RightK diagnostics.
RightLoc = Tok.is(RightK) ? consumeToken() : PreviousLoc;
} else if (parseMatchingToken(RightK, RightLoc, ErrorDiag, LeftLoc)) {
Status.setIsParseError();
}
return Status;
}
/// 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);
diagnose(Prev->getLoc(), diag::previous_decldef, Prev->getBaseName());
}
struct ParserUnit::Implementation {