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//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expression parsing implementation for C++.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/Basic/PrettyStackTrace.h"
#include "clang/Lex/LiteralSupport.h"
#include "clang/Parse/ParseDiagnostic.h"
#include "clang/Parse/RAIIObjectsForParser.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/ParsedTemplate.h"
#include "clang/Sema/Scope.h"
#include "llvm/Support/ErrorHandling.h"
#include <numeric>
using namespace clang;
static int SelectDigraphErrorMessage(tok::TokenKind Kind) {
switch (Kind) {
// template name
case tok::unknown: return 0;
// casts
case tok::kw_const_cast: return 1;
case tok::kw_dynamic_cast: return 2;
case tok::kw_reinterpret_cast: return 3;
case tok::kw_static_cast: return 4;
default:
llvm_unreachable("Unknown type for digraph error message.");
}
}
// Are the two tokens adjacent in the same source file?
bool Parser::areTokensAdjacent(const Token &First, const Token &Second) {
SourceManager &SM = PP.getSourceManager();
SourceLocation FirstLoc = SM.getSpellingLoc(First.getLocation());
SourceLocation FirstEnd = FirstLoc.getLocWithOffset(First.getLength());
return FirstEnd == SM.getSpellingLoc(Second.getLocation());
}
// Suggest fixit for "<::" after a cast.
static void FixDigraph(Parser &P, Preprocessor &PP, Token &DigraphToken,
Token &ColonToken, tok::TokenKind Kind, bool AtDigraph) {
// Pull '<:' and ':' off token stream.
if (!AtDigraph)
PP.Lex(DigraphToken);
PP.Lex(ColonToken);
SourceRange Range;
Range.setBegin(DigraphToken.getLocation());
Range.setEnd(ColonToken.getLocation());
P.Diag(DigraphToken.getLocation(), diag::err_missing_whitespace_digraph)
<< SelectDigraphErrorMessage(Kind)
<< FixItHint::CreateReplacement(Range, "< ::");
// Update token information to reflect their change in token type.
ColonToken.setKind(tok::coloncolon);
ColonToken.setLocation(ColonToken.getLocation().getLocWithOffset(-1));
ColonToken.setLength(2);
DigraphToken.setKind(tok::less);
DigraphToken.setLength(1);
// Push new tokens back to token stream.
PP.EnterToken(ColonToken, /*IsReinject*/ true);
if (!AtDigraph)
PP.EnterToken(DigraphToken, /*IsReinject*/ true);
}
// Check for '<::' which should be '< ::' instead of '[:' when following
// a template name.
void Parser::CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectType,
bool EnteringContext,
IdentifierInfo &II, CXXScopeSpec &SS) {
if (!Next.is(tok::l_square) || Next.getLength() != 2)
return;
Token SecondToken = GetLookAheadToken(2);
if (!SecondToken.is(tok::colon) || !areTokensAdjacent(Next, SecondToken))
return;
TemplateTy Template;
UnqualifiedId TemplateName;
TemplateName.setIdentifier(&II, Tok.getLocation());
bool MemberOfUnknownSpecialization;
if (!Actions.isTemplateName(getCurScope(), SS, /*hasTemplateKeyword=*/false,
TemplateName, ObjectType, EnteringContext,
Template, MemberOfUnknownSpecialization))
return;
FixDigraph(*this, PP, Next, SecondToken, tok::unknown,
/*AtDigraph*/false);
}
/// Parse global scope or nested-name-specifier if present.
///
/// Parses a C++ global scope specifier ('::') or nested-name-specifier (which
/// may be preceded by '::'). Note that this routine will not parse ::new or
/// ::delete; it will just leave them in the token stream.
///
/// '::'[opt] nested-name-specifier
/// '::'
///
/// nested-name-specifier:
/// type-name '::'
/// namespace-name '::'
/// nested-name-specifier identifier '::'
/// nested-name-specifier 'template'[opt] simple-template-id '::'
///
///
/// \param SS the scope specifier that will be set to the parsed
/// nested-name-specifier (or empty)
///
/// \param ObjectType if this nested-name-specifier is being parsed following
/// the "." or "->" of a member access expression, this parameter provides the
/// type of the object whose members are being accessed.
///
/// \param EnteringContext whether we will be entering into the context of
/// the nested-name-specifier after parsing it.
///
/// \param MayBePseudoDestructor When non-NULL, points to a flag that
/// indicates whether this nested-name-specifier may be part of a
/// pseudo-destructor name. In this case, the flag will be set false
/// if we don't actually end up parsing a destructor name. Moreorover,
/// if we do end up determining that we are parsing a destructor name,
/// the last component of the nested-name-specifier is not parsed as
/// part of the scope specifier.
///
/// \param IsTypename If \c true, this nested-name-specifier is known to be
/// part of a type name. This is used to improve error recovery.
///
/// \param LastII When non-NULL, points to an IdentifierInfo* that will be
/// filled in with the leading identifier in the last component of the
/// nested-name-specifier, if any.
///
/// \param OnlyNamespace If true, only considers namespaces in lookup.
///
/// \returns true if there was an error parsing a scope specifier
bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
ParsedType ObjectType,
bool EnteringContext,
bool *MayBePseudoDestructor,
bool IsTypename,
IdentifierInfo **LastII,
bool OnlyNamespace) {
assert(getLangOpts().CPlusPlus &&
"Call sites of this function should be guarded by checking for C++");
if (Tok.is(tok::annot_cxxscope)) {
assert(!LastII && "want last identifier but have already annotated scope");
assert(!MayBePseudoDestructor && "unexpected annot_cxxscope");
Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
Tok.getAnnotationRange(),
SS);
ConsumeAnnotationToken();
return false;
}
if (Tok.is(tok::annot_template_id)) {
// If the current token is an annotated template id, it may already have
// a scope specifier. Restore it.
TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
SS = TemplateId->SS;
}
// Has to happen before any "return false"s in this function.
bool CheckForDestructor = false;
if (MayBePseudoDestructor && *MayBePseudoDestructor) {
CheckForDestructor = true;
*MayBePseudoDestructor = false;
}
if (LastII)
*LastII = nullptr;
bool HasScopeSpecifier = false;
if (Tok.is(tok::coloncolon)) {
// ::new and ::delete aren't nested-name-specifiers.
tok::TokenKind NextKind = NextToken().getKind();
if (NextKind == tok::kw_new || NextKind == tok::kw_delete)
return false;
if (NextKind == tok::l_brace) {
// It is invalid to have :: {, consume the scope qualifier and pretend
// like we never saw it.
Diag(ConsumeToken(), diag::err_expected) << tok::identifier;
} else {
// '::' - Global scope qualifier.
if (Actions.ActOnCXXGlobalScopeSpecifier(ConsumeToken(), SS))
return true;
HasScopeSpecifier = true;
}
}
if (Tok.is(tok::kw___super)) {
SourceLocation SuperLoc = ConsumeToken();
if (!Tok.is(tok::coloncolon)) {
Diag(Tok.getLocation(), diag::err_expected_coloncolon_after_super);
return true;
}
return Actions.ActOnSuperScopeSpecifier(SuperLoc, ConsumeToken(), SS);
}
if (!HasScopeSpecifier &&
Tok.isOneOf(tok::kw_decltype, tok::annot_decltype)) {
DeclSpec DS(AttrFactory);
SourceLocation DeclLoc = Tok.getLocation();
SourceLocation EndLoc = ParseDecltypeSpecifier(DS);
SourceLocation CCLoc;
// Work around a standard defect: 'decltype(auto)::' is not a
// nested-name-specifier.
if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto ||
!TryConsumeToken(tok::coloncolon, CCLoc)) {
AnnotateExistingDecltypeSpecifier(DS, DeclLoc, EndLoc);
return false;
}
if (Actions.ActOnCXXNestedNameSpecifierDecltype(SS, DS, CCLoc))
SS.SetInvalid(SourceRange(DeclLoc, CCLoc));
HasScopeSpecifier = true;
}
// Preferred type might change when parsing qualifiers, we need the original.
auto SavedType = PreferredType;
while (true) {
if (HasScopeSpecifier) {
if (Tok.is(tok::code_completion)) {
// Code completion for a nested-name-specifier, where the code
// completion token follows the '::'.
Actions.CodeCompleteQualifiedId(getCurScope(), SS, EnteringContext,
ObjectType.get(),
SavedType.get(SS.getBeginLoc()));
// Include code completion token into the range of the scope otherwise
// when we try to annotate the scope tokens the dangling code completion
// token will cause assertion in
// Preprocessor::AnnotatePreviousCachedTokens.
SS.setEndLoc(Tok.getLocation());
cutOffParsing();
return true;
}
// C++ [basic.lookup.classref]p5:
// If the qualified-id has the form
//
// ::class-name-or-namespace-name::...
//
// the class-name-or-namespace-name is looked up in global scope as a
// class-name or namespace-name.
//
// To implement this, we clear out the object type as soon as we've
// seen a leading '::' or part of a nested-name-specifier.
ObjectType = nullptr;
}
// nested-name-specifier:
// nested-name-specifier 'template'[opt] simple-template-id '::'
// Parse the optional 'template' keyword, then make sure we have
// 'identifier <' after it.
if (Tok.is(tok::kw_template)) {
// If we don't have a scope specifier or an object type, this isn't a
// nested-name-specifier, since they aren't allowed to start with
// 'template'.
if (!HasScopeSpecifier && !ObjectType)
break;
TentativeParsingAction TPA(*this);
SourceLocation TemplateKWLoc = ConsumeToken();
UnqualifiedId TemplateName;
if (Tok.is(tok::identifier)) {
// Consume the identifier.
TemplateName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
ConsumeToken();
} else if (Tok.is(tok::kw_operator)) {
// We don't need to actually parse the unqualified-id in this case,
// because a simple-template-id cannot start with 'operator', but
// go ahead and parse it anyway for consistency with the case where
// we already annotated the template-id.
if (ParseUnqualifiedIdOperator(SS, EnteringContext, ObjectType,
TemplateName)) {
TPA.Commit();
break;
}
if (TemplateName.getKind() != UnqualifiedIdKind::IK_OperatorFunctionId &&
TemplateName.getKind() != UnqualifiedIdKind::IK_LiteralOperatorId) {
Diag(TemplateName.getSourceRange().getBegin(),
diag::err_id_after_template_in_nested_name_spec)
<< TemplateName.getSourceRange();
TPA.Commit();
break;
}
} else {
TPA.Revert();
break;
}
// If the next token is not '<', we have a qualified-id that refers
// to a template name, such as T::template apply, but is not a
// template-id.
if (Tok.isNot(tok::less)) {
TPA.Revert();
break;
}
// Commit to parsing the template-id.
TPA.Commit();
TemplateTy Template;
if (TemplateNameKind TNK = Actions.ActOnDependentTemplateName(
getCurScope(), SS, TemplateKWLoc, TemplateName, ObjectType,
EnteringContext, Template, /*AllowInjectedClassName*/ true)) {
if (AnnotateTemplateIdToken(Template, TNK, SS, TemplateKWLoc,
TemplateName, false))
return true;
} else
return true;
continue;
}
if (Tok.is(tok::annot_template_id) && NextToken().is(tok::coloncolon)) {
// We have
//
// template-id '::'
//
// So we need to check whether the template-id is a simple-template-id of
// the right kind (it should name a type or be dependent), and then
// convert it into a type within the nested-name-specifier.
TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
if (CheckForDestructor && GetLookAheadToken(2).is(tok::tilde)) {
*MayBePseudoDestructor = true;
return false;
}
if (LastII)
*LastII = TemplateId->Name;
// Consume the template-id token.
ConsumeAnnotationToken();
assert(Tok.is(tok::coloncolon) && "NextToken() not working properly!");
SourceLocation CCLoc = ConsumeToken();
HasScopeSpecifier = true;
ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
TemplateId->NumArgs);
if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(),
SS,
TemplateId->TemplateKWLoc,
TemplateId->Template,
TemplateId->TemplateNameLoc,
TemplateId->LAngleLoc,
TemplateArgsPtr,
TemplateId->RAngleLoc,
CCLoc,
EnteringContext)) {
SourceLocation StartLoc
= SS.getBeginLoc().isValid()? SS.getBeginLoc()
: TemplateId->TemplateNameLoc;
SS.SetInvalid(SourceRange(StartLoc, CCLoc));
}
continue;
}
// The rest of the nested-name-specifier possibilities start with
// tok::identifier.
if (Tok.isNot(tok::identifier))
break;
IdentifierInfo &II = *Tok.getIdentifierInfo();
// nested-name-specifier:
// type-name '::'
// namespace-name '::'
// nested-name-specifier identifier '::'
Token Next = NextToken();
Sema::NestedNameSpecInfo IdInfo(&II, Tok.getLocation(), Next.getLocation(),
ObjectType);
// If we get foo:bar, this is almost certainly a typo for foo::bar. Recover
// and emit a fixit hint for it.
if (Next.is(tok::colon) && !ColonIsSacred) {
if (Actions.IsInvalidUnlessNestedName(getCurScope(), SS, IdInfo,
EnteringContext) &&
// If the token after the colon isn't an identifier, it's still an
// error, but they probably meant something else strange so don't
// recover like this.
PP.LookAhead(1).is(tok::identifier)) {
Diag(Next, diag::err_unexpected_colon_in_nested_name_spec)
<< FixItHint::CreateReplacement(Next.getLocation(), "::");
// Recover as if the user wrote '::'.
Next.setKind(tok::coloncolon);
}
}
if (Next.is(tok::coloncolon) && GetLookAheadToken(2).is(tok::l_brace)) {
// It is invalid to have :: {, consume the scope qualifier and pretend
// like we never saw it.
Token Identifier = Tok; // Stash away the identifier.
ConsumeToken(); // Eat the identifier, current token is now '::'.
Diag(PP.getLocForEndOfToken(ConsumeToken()), diag::err_expected)
<< tok::identifier;
UnconsumeToken(Identifier); // Stick the identifier back.
Next = NextToken(); // Point Next at the '{' token.
}
if (Next.is(tok::coloncolon)) {
if (CheckForDestructor && GetLookAheadToken(2).is(tok::tilde) &&
!Actions.isNonTypeNestedNameSpecifier(getCurScope(), SS, IdInfo)) {
*MayBePseudoDestructor = true;
return false;
}
if (ColonIsSacred) {
const Token &Next2 = GetLookAheadToken(2);
if (Next2.is(tok::kw_private) || Next2.is(tok::kw_protected) ||
Next2.is(tok::kw_public) || Next2.is(tok::kw_virtual)) {
Diag(Next2, diag::err_unexpected_token_in_nested_name_spec)
<< Next2.getName()
<< FixItHint::CreateReplacement(Next.getLocation(), ":");
Token ColonColon;
PP.Lex(ColonColon);
ColonColon.setKind(tok::colon);
PP.EnterToken(ColonColon, /*IsReinject*/ true);
break;
}
}
if (LastII)
*LastII = &II;
// We have an identifier followed by a '::'. Lookup this name
// as the name in a nested-name-specifier.
Token Identifier = Tok;
SourceLocation IdLoc = ConsumeToken();
assert(Tok.isOneOf(tok::coloncolon, tok::colon) &&
"NextToken() not working properly!");
Token ColonColon = Tok;
SourceLocation CCLoc = ConsumeToken();
bool IsCorrectedToColon = false;
bool *CorrectionFlagPtr = ColonIsSacred ? &IsCorrectedToColon : nullptr;
if (Actions.ActOnCXXNestedNameSpecifier(
getCurScope(), IdInfo, EnteringContext, SS, false,
CorrectionFlagPtr, OnlyNamespace)) {
// Identifier is not recognized as a nested name, but we can have
// mistyped '::' instead of ':'.
if (CorrectionFlagPtr && IsCorrectedToColon) {
ColonColon.setKind(tok::colon);
PP.EnterToken(Tok, /*IsReinject*/ true);
PP.EnterToken(ColonColon, /*IsReinject*/ true);
Tok = Identifier;
break;
}
SS.SetInvalid(SourceRange(IdLoc, CCLoc));
}
HasScopeSpecifier = true;
continue;
}
CheckForTemplateAndDigraph(Next, ObjectType, EnteringContext, II, SS);
// nested-name-specifier:
// type-name '<'
if (Next.is(tok::less)) {
TemplateTy Template;
UnqualifiedId TemplateName;
TemplateName.setIdentifier(&II, Tok.getLocation());
bool MemberOfUnknownSpecialization;
if (TemplateNameKind TNK = Actions.isTemplateName(getCurScope(), SS,
/*hasTemplateKeyword=*/false,
TemplateName,
ObjectType,
EnteringContext,
Template,
MemberOfUnknownSpecialization)) {
// If lookup didn't find anything, we treat the name as a template-name
// anyway. C++20 requires this, and in prior language modes it improves
// error recovery. But before we commit to this, check that we actually
// have something that looks like a template-argument-list next.
if (!IsTypename && TNK == TNK_Undeclared_template &&
isTemplateArgumentList(1) == TPResult::False)
break;
// We have found a template name, so annotate this token
// with a template-id annotation. We do not permit the
// template-id to be translated into a type annotation,
// because some clients (e.g., the parsing of class template
// specializations) still want to see the original template-id
// token.
ConsumeToken();
if (AnnotateTemplateIdToken(Template, TNK, SS, SourceLocation(),
TemplateName, false))
return true;
continue;
}
if (MemberOfUnknownSpecialization && (ObjectType || SS.isSet()) &&
(IsTypename || isTemplateArgumentList(1) == TPResult::True)) {
// We have something like t::getAs<T>, where getAs is a
// member of an unknown specialization. However, this will only
// parse correctly as a template, so suggest the keyword 'template'
// before 'getAs' and treat this as a dependent template name.
unsigned DiagID = diag::err_missing_dependent_template_keyword;
if (getLangOpts().MicrosoftExt)
DiagID = diag::warn_missing_dependent_template_keyword;
Diag(Tok.getLocation(), DiagID)
<< II.getName()
<< FixItHint::CreateInsertion(Tok.getLocation(), "template ");
if (TemplateNameKind TNK = Actions.ActOnDependentTemplateName(
getCurScope(), SS, Tok.getLocation(), TemplateName, ObjectType,
EnteringContext, Template, /*AllowInjectedClassName*/ true)) {
// Consume the identifier.
ConsumeToken();
if (AnnotateTemplateIdToken(Template, TNK, SS, SourceLocation(),
TemplateName, false))
return true;
}
else
return true;
continue;
}
}
// We don't have any tokens that form the beginning of a
// nested-name-specifier, so we're done.
break;
}
// Even if we didn't see any pieces of a nested-name-specifier, we
// still check whether there is a tilde in this position, which
// indicates a potential pseudo-destructor.
if (CheckForDestructor && Tok.is(tok::tilde))
*MayBePseudoDestructor = true;
return false;
}
ExprResult Parser::tryParseCXXIdExpression(CXXScopeSpec &SS, bool isAddressOfOperand,
Token &Replacement) {
SourceLocation TemplateKWLoc;
UnqualifiedId Name;
if (ParseUnqualifiedId(SS,
/*EnteringContext=*/false,
/*AllowDestructorName=*/false,
/*AllowConstructorName=*/false,
/*AllowDeductionGuide=*/false,
/*ObjectType=*/nullptr, &TemplateKWLoc, Name))
return ExprError();
// This is only the direct operand of an & operator if it is not
// followed by a postfix-expression suffix.
if (isAddressOfOperand && isPostfixExpressionSuffixStart())
isAddressOfOperand = false;
ExprResult E = Actions.ActOnIdExpression(
getCurScope(), SS, TemplateKWLoc, Name, Tok.is(tok::l_paren),
isAddressOfOperand, /*CCC=*/nullptr, /*IsInlineAsmIdentifier=*/false,
&Replacement);
if (!E.isInvalid() && !E.isUnset() && Tok.is(tok::less))
checkPotentialAngleBracket(E);
return E;
}
/// ParseCXXIdExpression - Handle id-expression.
///
/// id-expression:
/// unqualified-id
/// qualified-id
///
/// qualified-id:
/// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
/// '::' identifier
/// '::' operator-function-id
/// '::' template-id
///
/// NOTE: The standard specifies that, for qualified-id, the parser does not
/// expect:
///
/// '::' conversion-function-id
/// '::' '~' class-name
///
/// This may cause a slight inconsistency on diagnostics:
///
/// class C {};
/// namespace A {}
/// void f() {
/// :: A :: ~ C(); // Some Sema error about using destructor with a
/// // namespace.
/// :: ~ C(); // Some Parser error like 'unexpected ~'.
/// }
///
/// We simplify the parser a bit and make it work like:
///
/// qualified-id:
/// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
/// '::' unqualified-id
///
/// That way Sema can handle and report similar errors for namespaces and the
/// global scope.
///
/// The isAddressOfOperand parameter indicates that this id-expression is a
/// direct operand of the address-of operator. This is, besides member contexts,
/// the only place where a qualified-id naming a non-static class member may
/// appear.
///
ExprResult Parser::ParseCXXIdExpression(bool isAddressOfOperand) {
// qualified-id:
// '::'[opt] nested-name-specifier 'template'[opt] unqualified-id
// '::' unqualified-id
//
CXXScopeSpec SS;
ParseOptionalCXXScopeSpecifier(SS, nullptr, /*EnteringContext=*/false);
Token Replacement;
ExprResult Result =
tryParseCXXIdExpression(SS, isAddressOfOperand, Replacement);
if (Result.isUnset()) {
// If the ExprResult is valid but null, then typo correction suggested a
// keyword replacement that needs to be reparsed.
UnconsumeToken(Replacement);
Result = tryParseCXXIdExpression(SS, isAddressOfOperand, Replacement);
}
assert(!Result.isUnset() && "Typo correction suggested a keyword replacement "
"for a previous keyword suggestion");
return Result;
}
/// ParseLambdaExpression - Parse a C++11 lambda expression.
///
/// lambda-expression:
/// lambda-introducer lambda-declarator[opt] compound-statement
/// lambda-introducer '<' template-parameter-list '>'
/// lambda-declarator[opt] compound-statement
///
/// lambda-introducer:
/// '[' lambda-capture[opt] ']'
///
/// lambda-capture:
/// capture-default
/// capture-list
/// capture-default ',' capture-list
///
/// capture-default:
/// '&'
/// '='
///
/// capture-list:
/// capture
/// capture-list ',' capture
///
/// capture:
/// simple-capture
/// init-capture [C++1y]
///
/// simple-capture:
/// identifier
/// '&' identifier
/// 'this'
///
/// init-capture: [C++1y]
/// identifier initializer
/// '&' identifier initializer
///
/// lambda-declarator:
/// '(' parameter-declaration-clause ')' attribute-specifier[opt]
/// 'mutable'[opt] exception-specification[opt]
/// trailing-return-type[opt]
///
ExprResult Parser::ParseLambdaExpression() {
// Parse lambda-introducer.
LambdaIntroducer Intro;
if (ParseLambdaIntroducer(Intro)) {
SkipUntil(tok::r_square, StopAtSemi);
SkipUntil(tok::l_brace, StopAtSemi);
SkipUntil(tok::r_brace, StopAtSemi);
return ExprError();
}
return ParseLambdaExpressionAfterIntroducer(Intro);
}
/// Use lookahead and potentially tentative parsing to determine if we are
/// looking at a C++11 lambda expression, and parse it if we are.
///
/// If we are not looking at a lambda expression, returns ExprError().
ExprResult Parser::TryParseLambdaExpression() {
assert(getLangOpts().CPlusPlus11
&& Tok.is(tok::l_square)
&& "Not at the start of a possible lambda expression.");
const Token Next = NextToken();
if (Next.is(tok::eof)) // Nothing else to lookup here...
return ExprEmpty();
const Token After = GetLookAheadToken(2);
// If lookahead indicates this is a lambda...
if (Next.is(tok::r_square) || // []
Next.is(tok::equal) || // [=
(Next.is(tok::amp) && // [&] or [&,
After.isOneOf(tok::r_square, tok::comma)) ||
(Next.is(tok::identifier) && // [identifier]
After.is(tok::r_square)) ||
Next.is(tok::ellipsis)) { // [...
return ParseLambdaExpression();
}
// If lookahead indicates an ObjC message send...
// [identifier identifier
if (Next.is(tok::identifier) && After.is(tok::identifier))
return ExprEmpty();
// Here, we're stuck: lambda introducers and Objective-C message sends are
// unambiguous, but it requires arbitrary lookhead. [a,b,c,d,e,f,g] is a
// lambda, and [a,b,c,d,e,f,g h] is a Objective-C message send. Instead of
// writing two routines to parse a lambda introducer, just try to parse
// a lambda introducer first, and fall back if that fails.
LambdaIntroducer Intro;
{
TentativeParsingAction TPA(*this);
LambdaIntroducerTentativeParse Tentative;
if (ParseLambdaIntroducer(Intro, &Tentative)) {
TPA.Commit();
return ExprError();
}
switch (Tentative) {
case LambdaIntroducerTentativeParse::Success:
TPA.Commit();
break;
case LambdaIntroducerTentativeParse::Incomplete:
// Didn't fully parse the lambda-introducer, try again with a
// non-tentative parse.
TPA.Revert();
Intro = LambdaIntroducer();
if (ParseLambdaIntroducer(Intro))
return ExprError();
break;
case LambdaIntroducerTentativeParse::MessageSend:
case LambdaIntroducerTentativeParse::Invalid:
// Not a lambda-introducer, might be a message send.
TPA.Revert();
return ExprEmpty();
}
}
return ParseLambdaExpressionAfterIntroducer(Intro);
}
/// Parse a lambda introducer.
/// \param Intro A LambdaIntroducer filled in with information about the
/// contents of the lambda-introducer.
/// \param Tentative If non-null, we are disambiguating between a
/// lambda-introducer and some other construct. In this mode, we do not
/// produce any diagnostics or take any other irreversible action unless
/// we're sure that this is a lambda-expression.
/// \return \c true if parsing (or disambiguation) failed with a diagnostic and
/// the caller should bail out / recover.
bool Parser::ParseLambdaIntroducer(LambdaIntroducer &Intro,
LambdaIntroducerTentativeParse *Tentative) {
if (Tentative)
*Tentative = LambdaIntroducerTentativeParse::Success;
assert(Tok.is(tok::l_square) && "Lambda expressions begin with '['.");
BalancedDelimiterTracker T(*this, tok::l_square);
T.consumeOpen();
Intro.Range.setBegin(T.getOpenLocation());
bool First = true;
// Produce a diagnostic if we're not tentatively parsing; otherwise track
// that our parse has failed.
auto Invalid = [&](llvm::function_ref<void()> Action) {
if (Tentative) {
*Tentative = LambdaIntroducerTentativeParse::Invalid;
return false;
}
Action();
return true;
};
// Perform some irreversible action if this is a non-tentative parse;
// otherwise note that our actions were incomplete.
auto NonTentativeAction = [&](llvm::function_ref<void()> Action) {
if (Tentative)
*Tentative = LambdaIntroducerTentativeParse::Incomplete;
else
Action();
};
// Parse capture-default.
if (Tok.is(tok::amp) &&
(NextToken().is(tok::comma) || NextToken().is(tok::r_square))) {
Intro.Default = LCD_ByRef;
Intro.DefaultLoc = ConsumeToken();
First = false;
if (!Tok.getIdentifierInfo()) {
// This can only be a lambda; no need for tentative parsing any more.
// '[[and]]' can still be an attribute, though.
Tentative = nullptr;
}
} else if (Tok.is(tok::equal)) {
Intro.Default = LCD_ByCopy;
Intro.DefaultLoc = ConsumeToken();
First = false;
Tentative = nullptr;
}
while (Tok.isNot(tok::r_square)) {
if (!First) {
if (Tok.isNot(tok::comma)) {
// Provide a completion for a lambda introducer here. Except
// in Objective-C, where this is Almost Surely meant to be a message
// send. In that case, fail here and let the ObjC message
// expression parser perform the completion.
if (Tok.is(tok::code_completion) &&
!(getLangOpts().ObjC && Tentative)) {
Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro,
/*AfterAmpersand=*/false);
cutOffParsing();
break;
}
return Invalid([&] {
Diag(Tok.getLocation(), diag::err_expected_comma_or_rsquare);
});
}
ConsumeToken();
}
if (Tok.is(tok::code_completion)) {
// If we're in Objective-C++ and we have a bare '[', then this is more
// likely to be a message receiver.
if (getLangOpts().ObjC && Tentative && First)
Actions.CodeCompleteObjCMessageReceiver(getCurScope());
else
Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro,
/*AfterAmpersand=*/false);
cutOffParsing();
break;
}
First = false;
// Parse capture.
LambdaCaptureKind Kind = LCK_ByCopy;
LambdaCaptureInitKind InitKind = LambdaCaptureInitKind::NoInit;
SourceLocation Loc;
IdentifierInfo *Id = nullptr;
SourceLocation EllipsisLocs[4];
ExprResult Init;
SourceLocation LocStart = Tok.getLocation();
if (Tok.is(tok::star)) {
Loc = ConsumeToken();
if (Tok.is(tok::kw_this)) {
ConsumeToken();
Kind = LCK_StarThis;
} else {
return Invalid([&] {
Diag(Tok.getLocation(), diag::err_expected_star_this_capture);
});
}
} else if (Tok.is(tok::kw_this)) {
Kind = LCK_This;
Loc = ConsumeToken();
} else {
TryConsumeToken(tok::ellipsis, EllipsisLocs[0]);
if (Tok.is(tok::amp)) {
Kind = LCK_ByRef;
ConsumeToken();
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteLambdaIntroducer(getCurScope(), Intro,
/*AfterAmpersand=*/true);
cutOffParsing();
break;
}
}
TryConsumeToken(tok::ellipsis, EllipsisLocs[1]);
if (Tok.is(tok::identifier)) {
Id = Tok.getIdentifierInfo();
Loc = ConsumeToken();
} else if (Tok.is(tok::kw_this)) {
return Invalid([&] {
// FIXME: Suggest a fixit here.
Diag(Tok.getLocation(), diag::err_this_captured_by_reference);
});
} else {
return Invalid([&] {
Diag(Tok.getLocation(), diag::err_expected_capture);
});
}
TryConsumeToken(tok::ellipsis, EllipsisLocs[2]);
if (Tok.is(tok::l_paren)) {
BalancedDelimiterTracker Parens(*this, tok::l_paren);
Parens.consumeOpen();
InitKind = LambdaCaptureInitKind::DirectInit;
ExprVector Exprs;
CommaLocsTy Commas;
if (Tentative) {
Parens.skipToEnd();
*Tentative = LambdaIntroducerTentativeParse::Incomplete;
} else if (ParseExpressionList(Exprs, Commas)) {
Parens.skipToEnd();
Init = ExprError();
} else {
Parens.consumeClose();
Init = Actions.ActOnParenListExpr(Parens.getOpenLocation(),
Parens.getCloseLocation(),
Exprs);
}
} else if (Tok.isOneOf(tok::l_brace, tok::equal)) {
// Each lambda init-capture forms its own full expression, which clears
// Actions.MaybeODRUseExprs. So create an expression evaluation context
// to save the necessary state, and restore it later.
EnterExpressionEvaluationContext EC(
Actions, Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
if (TryConsumeToken(tok::equal))
InitKind = LambdaCaptureInitKind::CopyInit;
else
InitKind = LambdaCaptureInitKind::ListInit;
if (!Tentative) {
Init = ParseInitializer();
} else if (Tok.is(tok::l_brace)) {
BalancedDelimiterTracker Braces(*this, tok::l_brace);
Braces.consumeOpen();
Braces.skipToEnd();
*Tentative = LambdaIntroducerTentativeParse::Incomplete;
} else {
// We're disambiguating this:
//
// [..., x = expr
//
// We need to find the end of the following expression in order to
// determine whether this is an Obj-C message send's receiver, a
// C99 designator, or a lambda init-capture.
//
// Parse the expression to find where it ends, and annotate it back
// onto the tokens. We would have parsed this expression the same way
// in either case: both the RHS of an init-capture and the RHS of an
// assignment expression are parsed as an initializer-clause, and in
// neither case can anything be added to the scope between the '[' and
// here.
//
// FIXME: This is horrible. Adding a mechanism to skip an expression
// would be much cleaner.
// FIXME: If there is a ',' before the next ']' or ':', we can skip to
// that instead. (And if we see a ':' with no matching '?', we can
// classify this as an Obj-C message send.)
SourceLocation StartLoc = Tok.getLocation();
InMessageExpressionRAIIObject MaybeInMessageExpression(*this, true);
Init = ParseInitializer();
if (!Init.isInvalid())
Init = Actions.CorrectDelayedTyposInExpr(Init.get());
if (Tok.getLocation() != StartLoc) {
// Back out the lexing of the token after the initializer.
PP.RevertCachedTokens(1);
// Replace the consumed tokens with an appropriate annotation.
Tok.setLocation(StartLoc);
Tok.setKind(tok::annot_primary_expr);
setExprAnnotation(Tok, Init);
Tok.setAnnotationEndLoc(PP.getLastCachedTokenLocation());
PP.AnnotateCachedTokens(Tok);
// Consume the annotated initializer.
ConsumeAnnotationToken();
}
}
}
TryConsumeToken(tok::ellipsis, EllipsisLocs[3]);
}
// Check if this is a message send before we act on a possible init-capture.
if (Tentative && Tok.is(tok::identifier) &&
NextToken().isOneOf(tok::colon, tok::r_square)) {
// This can only be a message send. We're done with disambiguation.
*Tentative = LambdaIntroducerTentativeParse::MessageSend;
return false;
}
// Ensure that any ellipsis was in the right place.
SourceLocation EllipsisLoc;
if (std::any_of(std::begin(EllipsisLocs), std::end(EllipsisLocs),
[](SourceLocation Loc) { return Loc.isValid(); })) {
// The '...' should appear before the identifier in an init-capture, and
// after the identifier otherwise.
bool InitCapture = InitKind != LambdaCaptureInitKind::NoInit;
SourceLocation *ExpectedEllipsisLoc =
!InitCapture ? &EllipsisLocs[2] :
Kind == LCK_ByRef ? &EllipsisLocs[1] :
&EllipsisLocs[0];
EllipsisLoc = *ExpectedEllipsisLoc;
unsigned DiagID = 0;
if (EllipsisLoc.isInvalid()) {
DiagID = diag::err_lambda_capture_misplaced_ellipsis;
for (SourceLocation Loc : EllipsisLocs) {
if (Loc.isValid())
EllipsisLoc = Loc;
}
} else {
unsigned NumEllipses = std::accumulate(
std::begin(EllipsisLocs), std::end(EllipsisLocs), 0,
[](int N, SourceLocation Loc) { return N + Loc.isValid(); });
if (NumEllipses > 1)
DiagID = diag::err_lambda_capture_multiple_ellipses;
}
if (DiagID) {
NonTentativeAction([&] {
// Point the diagnostic at the first misplaced ellipsis.
SourceLocation DiagLoc;
for (SourceLocation &Loc : EllipsisLocs) {
if (&Loc != ExpectedEllipsisLoc && Loc.isValid()) {
DiagLoc = Loc;
break;
}
}
assert(DiagLoc.isValid() && "no location for diagnostic");
// Issue the diagnostic and produce fixits showing where the ellipsis
// should have been written.
auto &&D = Diag(DiagLoc, DiagID);
if (DiagID == diag::err_lambda_capture_misplaced_ellipsis) {
SourceLocation ExpectedLoc =
InitCapture ? Loc
: Lexer::getLocForEndOfToken(
Loc, 0, PP.getSourceManager(), getLangOpts());
D << InitCapture << FixItHint::CreateInsertion(ExpectedLoc, "...");
}
for (SourceLocation &Loc : EllipsisLocs) {
if (&Loc != ExpectedEllipsisLoc && Loc.isValid())
D << FixItHint::CreateRemoval(Loc);
}
});
}
}
// Process the init-capture initializers now rather than delaying until we
// form the lambda-expression so that they can be handled in the context
// enclosing the lambda-expression, rather than in the context of the
// lambda-expression itself.
ParsedType InitCaptureType;
if (Init.isUsable())
Init = Actions.CorrectDelayedTyposInExpr(Init.get());
if (Init.isUsable()) {
NonTentativeAction([&] {
// Get the pointer and store it in an lvalue, so we can use it as an
// out argument.
Expr *InitExpr = Init.get();
// This performs any lvalue-to-rvalue conversions if necessary, which
// can affect what gets captured in the containing decl-context.
InitCaptureType = Actions.actOnLambdaInitCaptureInitialization(
Loc, Kind == LCK_ByRef, EllipsisLoc, Id, InitKind, InitExpr);
Init = InitExpr;
});
}
SourceLocation LocEnd = PrevTokLocation;
Intro.addCapture(Kind, Loc, Id, EllipsisLoc, InitKind, Init,
InitCaptureType, SourceRange(LocStart, LocEnd));
}
T.consumeClose();
Intro.Range.setEnd(T.getCloseLocation());
return false;
}
static void tryConsumeLambdaSpecifierToken(Parser &P,
SourceLocation &MutableLoc,
SourceLocation &ConstexprLoc,
SourceLocation &ConstevalLoc,
SourceLocation &DeclEndLoc) {
assert(MutableLoc.isInvalid());
assert(ConstexprLoc.isInvalid());
// Consume constexpr-opt mutable-opt in any sequence, and set the DeclEndLoc
// to the final of those locations. Emit an error if we have multiple
// copies of those keywords and recover.
while (true) {
switch (P.getCurToken().getKind()) {
case tok::kw_mutable: {
if (MutableLoc.isValid()) {
P.Diag(P.getCurToken().getLocation(),
diag::err_lambda_decl_specifier_repeated)
<< 0 << FixItHint::CreateRemoval(P.getCurToken().getLocation());
}
MutableLoc = P.ConsumeToken();
DeclEndLoc = MutableLoc;
break /*switch*/;
}
case tok::kw_constexpr:
if (ConstexprLoc.isValid()) {
P.Diag(P.getCurToken().getLocation(),
diag::err_lambda_decl_specifier_repeated)
<< 1 << FixItHint::CreateRemoval(P.getCurToken().getLocation());
}
ConstexprLoc = P.ConsumeToken();
DeclEndLoc = ConstexprLoc;
break /*switch*/;
case tok::kw_consteval:
if (ConstevalLoc.isValid()) {
P.Diag(P.getCurToken().getLocation(),
diag::err_lambda_decl_specifier_repeated)
<< 2 << FixItHint::CreateRemoval(P.getCurToken().getLocation());
}
ConstevalLoc = P.ConsumeToken();
DeclEndLoc = ConstevalLoc;
break /*switch*/;
default:
return;
}
}
}
static void
addConstexprToLambdaDeclSpecifier(Parser &P, SourceLocation ConstexprLoc,
DeclSpec &DS) {
if (ConstexprLoc.isValid()) {
P.Diag(ConstexprLoc, !P.getLangOpts().CPlusPlus17
? diag::ext_constexpr_on_lambda_cxx17
: diag::warn_cxx14_compat_constexpr_on_lambda);
const char *PrevSpec = nullptr;
unsigned DiagID = 0;
DS.SetConstexprSpec(CSK_constexpr, ConstexprLoc, PrevSpec, DiagID);
assert(PrevSpec == nullptr && DiagID == 0 &&
"Constexpr cannot have been set previously!");
}
}
static void addConstevalToLambdaDeclSpecifier(Parser &P,
SourceLocation ConstevalLoc,
DeclSpec &DS) {
if (ConstevalLoc.isValid()) {
P.Diag(ConstevalLoc, diag::warn_cxx20_compat_consteval);
const char *PrevSpec = nullptr;
unsigned DiagID = 0;
DS.SetConstexprSpec(CSK_consteval, ConstevalLoc, PrevSpec, DiagID);
if (DiagID != 0)
P.Diag(ConstevalLoc, DiagID) << PrevSpec;
}
}
/// ParseLambdaExpressionAfterIntroducer - Parse the rest of a lambda
/// expression.
ExprResult Parser::ParseLambdaExpressionAfterIntroducer(
LambdaIntroducer &Intro) {
SourceLocation LambdaBeginLoc = Intro.Range.getBegin();
Diag(LambdaBeginLoc, diag::warn_cxx98_compat_lambda);
PrettyStackTraceLoc CrashInfo(PP.getSourceManager(), LambdaBeginLoc,
"lambda expression parsing");
// FIXME: Call into Actions to add any init-capture declarations to the
// scope while parsing the lambda-declarator and compound-statement.
// Parse lambda-declarator[opt].
DeclSpec DS(AttrFactory);
Declarator D(DS, DeclaratorContext::LambdaExprContext);
TemplateParameterDepthRAII CurTemplateDepthTracker(TemplateParameterDepth);
Actions.PushLambdaScope();
ParsedAttributes Attr(AttrFactory);
SourceLocation DeclLoc = Tok.getLocation();
if (getLangOpts().CUDA) {
// In CUDA code, GNU attributes are allowed to appear immediately after the
// "[...]", even if there is no "(...)" before the lambda body.
MaybeParseGNUAttributes(D);
}
// Helper to emit a warning if we see a CUDA host/device/global attribute
// after '(...)'. nvcc doesn't accept this.
auto WarnIfHasCUDATargetAttr = [&] {
if (getLangOpts().CUDA)
for (const ParsedAttr &A : Attr)
if (A.getKind() == ParsedAttr::AT_CUDADevice ||
A.getKind() == ParsedAttr::AT_CUDAHost ||
A.getKind() == ParsedAttr::AT_CUDAGlobal)
Diag(A.getLoc(), diag::warn_cuda_attr_lambda_position)
<< A.getName()->getName();
};
// FIXME: Consider allowing this as an extension for GCC compatibiblity.
const bool HasExplicitTemplateParams = Tok.is(tok::less);
ParseScope TemplateParamScope(this, Scope::TemplateParamScope,
/*EnteredScope=*/HasExplicitTemplateParams);
if (HasExplicitTemplateParams) {
Diag(Tok, getLangOpts().CPlusPlus2a
? diag::warn_cxx17_compat_lambda_template_parameter_list
: diag::ext_lambda_template_parameter_list);
SmallVector<NamedDecl*, 4> TemplateParams;
SourceLocation LAngleLoc, RAngleLoc;
if (ParseTemplateParameters(CurTemplateDepthTracker.getDepth(),
TemplateParams, LAngleLoc, RAngleLoc)) {
Actions.ActOnLambdaError(LambdaBeginLoc, getCurScope());
return ExprError();
}
if (TemplateParams.empty()) {
Diag(RAngleLoc,
diag::err_lambda_template_parameter_list_empty);
} else {
Actions.ActOnLambdaExplicitTemplateParameterList(
LAngleLoc, TemplateParams, RAngleLoc);
++CurTemplateDepthTracker;
}
}
TypeResult TrailingReturnType;
if (Tok.is(tok::l_paren)) {
ParseScope PrototypeScope(this,
Scope::FunctionPrototypeScope |
Scope::FunctionDeclarationScope |
Scope::DeclScope);
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
SourceLocation LParenLoc = T.getOpenLocation();
// Parse parameter-declaration-clause.
SmallVector<DeclaratorChunk::ParamInfo, 16> ParamInfo;
SourceLocation EllipsisLoc;
if (Tok.isNot(tok::r_paren)) {
Actions.RecordParsingTemplateParameterDepth(
CurTemplateDepthTracker.getOriginalDepth());
ParseParameterDeclarationClause(D, Attr, ParamInfo, EllipsisLoc);
// For a generic lambda, each 'auto' within the parameter declaration
// clause creates a template type parameter, so increment the depth.
// If we've parsed any explicit template parameters, then the depth will
// have already been incremented. So we make sure that at most a single
// depth level is added.
if (Actions.getCurGenericLambda())
CurTemplateDepthTracker.setAddedDepth(1);
}
T.consumeClose();
SourceLocation RParenLoc = T.getCloseLocation();
SourceLocation DeclEndLoc = RParenLoc;
// GNU-style attributes must be parsed before the mutable specifier to be
// compatible with GCC.
MaybeParseGNUAttributes(Attr, &DeclEndLoc);
// MSVC-style attributes must be parsed before the mutable specifier to be
// compatible with MSVC.
MaybeParseMicrosoftDeclSpecs(Attr, &DeclEndLoc);
// Parse mutable-opt and/or constexpr-opt or consteval-opt, and update the
// DeclEndLoc.
SourceLocation MutableLoc;
SourceLocation ConstexprLoc;
SourceLocation ConstevalLoc;
tryConsumeLambdaSpecifierToken(*this, MutableLoc, ConstexprLoc,
ConstevalLoc, DeclEndLoc);
addConstexprToLambdaDeclSpecifier(*this, ConstexprLoc, DS);
addConstevalToLambdaDeclSpecifier(*this, ConstevalLoc, DS);
// Parse exception-specification[opt].
ExceptionSpecificationType ESpecType = EST_None;
SourceRange ESpecRange;
SmallVector<ParsedType, 2> DynamicExceptions;
SmallVector<SourceRange, 2> DynamicExceptionRanges;
ExprResult NoexceptExpr;
CachedTokens *ExceptionSpecTokens;
ESpecType = tryParseExceptionSpecification(/*Delayed=*/false,
ESpecRange,
DynamicExceptions,
DynamicExceptionRanges,
NoexceptExpr,
ExceptionSpecTokens);
if (ESpecType != EST_None)
DeclEndLoc = ESpecRange.getEnd();
// Parse attribute-specifier[opt].
MaybeParseCXX11Attributes(Attr, &DeclEndLoc);
SourceLocation FunLocalRangeEnd = DeclEndLoc;
// Parse trailing-return-type[opt].
if (Tok.is(tok::arrow)) {
FunLocalRangeEnd = Tok.getLocation();
SourceRange Range;
TrailingReturnType =
ParseTrailingReturnType(Range, /*MayBeFollowedByDirectInit*/ false);
if (Range.getEnd().isValid())
DeclEndLoc = Range.getEnd();
}
PrototypeScope.Exit();
WarnIfHasCUDATargetAttr();
SourceLocation NoLoc;
D.AddTypeInfo(DeclaratorChunk::getFunction(
/*hasProto=*/true,
/*isAmbiguous=*/false, LParenLoc, ParamInfo.data(),
ParamInfo.size(), EllipsisLoc, RParenLoc,
/*RefQualifierIsLValueRef=*/true,
/*RefQualifierLoc=*/NoLoc, MutableLoc, ESpecType,
ESpecRange, DynamicExceptions.data(),
DynamicExceptionRanges.data(), DynamicExceptions.size(),
NoexceptExpr.isUsable() ? NoexceptExpr.get() : nullptr,
/*ExceptionSpecTokens*/ nullptr,
/*DeclsInPrototype=*/None, LParenLoc, FunLocalRangeEnd, D,
TrailingReturnType),
std::move(Attr), DeclEndLoc);
} else if (Tok.isOneOf(tok::kw_mutable, tok::arrow, tok::kw___attribute,
tok::kw_constexpr, tok::kw_consteval) ||
(Tok.is(tok::l_square) && NextToken().is(tok::l_square))) {
// It's common to forget that one needs '()' before 'mutable', an attribute
// specifier, or the result type. Deal with this.
unsigned TokKind = 0;
switch (Tok.getKind()) {
case tok::kw_mutable: TokKind = 0; break;
case tok::arrow: TokKind = 1; break;
case tok::kw___attribute:
case tok::l_square: TokKind = 2; break;
case tok::kw_constexpr: TokKind = 3; break;
case tok::kw_consteval: TokKind = 4; break;
default: llvm_unreachable("Unknown token kind");
}
Diag(Tok, diag::err_lambda_missing_parens)
<< TokKind
<< FixItHint::CreateInsertion(Tok.getLocation(), "() ");
SourceLocation DeclEndLoc = DeclLoc;
// GNU-style attributes must be parsed before the mutable specifier to be
// compatible with GCC.
MaybeParseGNUAttributes(Attr, &DeclEndLoc);
// Parse 'mutable', if it's there.
SourceLocation MutableLoc;
if (Tok.is(tok::kw_mutable)) {
MutableLoc = ConsumeToken();
DeclEndLoc = MutableLoc;
}
// Parse attribute-specifier[opt].
MaybeParseCXX11Attributes(Attr, &DeclEndLoc);
// Parse the return type, if there is one.
if (Tok.is(tok::arrow)) {
SourceRange Range;
TrailingReturnType =
ParseTrailingReturnType(Range, /*MayBeFollowedByDirectInit*/ false);
if (Range.getEnd().isValid())
DeclEndLoc = Range.getEnd();
}
WarnIfHasCUDATargetAttr();
SourceLocation NoLoc;
D.AddTypeInfo(DeclaratorChunk::getFunction(
/*hasProto=*/true,
/*isAmbiguous=*/false,
/*LParenLoc=*/NoLoc,
/*Params=*/nullptr,
/*NumParams=*/0,
/*EllipsisLoc=*/NoLoc,
/*RParenLoc=*/NoLoc,
/*RefQualifierIsLValueRef=*/true,
/*RefQualifierLoc=*/NoLoc, MutableLoc, EST_None,
/*ESpecRange=*/SourceRange(),
/*Exceptions=*/nullptr,
/*ExceptionRanges=*/nullptr,
/*NumExceptions=*/0,
/*NoexceptExpr=*/nullptr,
/*ExceptionSpecTokens=*/nullptr,
/*DeclsInPrototype=*/None, DeclLoc, DeclEndLoc, D,
TrailingReturnType),
std::move(Attr), DeclEndLoc);
}
// FIXME: Rename BlockScope -> ClosureScope if we decide to continue using
// it.
unsigned ScopeFlags = Scope::BlockScope | Scope::FnScope | Scope::DeclScope |
Scope::CompoundStmtScope;
ParseScope BodyScope(this, ScopeFlags);
Actions.ActOnStartOfLambdaDefinition(Intro, D, getCurScope());
// Parse compound-statement.
if (!Tok.is(tok::l_brace)) {
Diag(Tok, diag::err_expected_lambda_body);
Actions.ActOnLambdaError(LambdaBeginLoc, getCurScope());
return ExprError();
}
StmtResult Stmt(ParseCompoundStatementBody());
BodyScope.Exit();
TemplateParamScope.Exit();
if (!Stmt.isInvalid() && !TrailingReturnType.isInvalid())
return Actions.ActOnLambdaExpr(LambdaBeginLoc, Stmt.get(), getCurScope());
Actions.ActOnLambdaError(LambdaBeginLoc, getCurScope());
return ExprError();
}
/// ParseCXXCasts - This handles the various ways to cast expressions to another
/// type.
///
/// postfix-expression: [C++ 5.2p1]
/// 'dynamic_cast' '<' type-name '>' '(' expression ')'
/// 'static_cast' '<' type-name '>' '(' expression ')'
/// 'reinterpret_cast' '<' type-name '>' '(' expression ')'
/// 'const_cast' '<' type-name '>' '(' expression ')'
///
ExprResult Parser::ParseCXXCasts() {
tok::TokenKind Kind = Tok.getKind();
const char *CastName = nullptr; // For error messages
switch (Kind) {
default: llvm_unreachable("Unknown C++ cast!");
case tok::kw_const_cast: CastName = "const_cast"; break;
case tok::kw_dynamic_cast: CastName = "dynamic_cast"; break;
case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
case tok::kw_static_cast: CastName = "static_cast"; break;
}
SourceLocation OpLoc = ConsumeToken();
SourceLocation LAngleBracketLoc = Tok.getLocation();
// Check for "<::" which is parsed as "[:". If found, fix token stream,
// diagnose error, suggest fix, and recover parsing.
if (Tok.is(tok::l_square) && Tok.getLength() == 2) {
Token Next = NextToken();
if (Next.is(tok::colon) && areTokensAdjacent(Tok, Next))
FixDigraph(*this, PP, Tok, Next, Kind, /*AtDigraph*/true);
}
if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
return ExprError();
// Parse the common declaration-specifiers piece.
DeclSpec DS(AttrFactory);
ParseSpecifierQualifierList(DS);
// Parse the abstract-declarator, if present.
Declarator DeclaratorInfo(DS, DeclaratorContext::TypeNameContext);
ParseDeclarator(DeclaratorInfo);
SourceLocation RAngleBracketLoc = Tok.getLocation();
if (ExpectAndConsume(tok::greater))
return ExprError(Diag(LAngleBracketLoc, diag::note_matching) << tok::less);
BalancedDelimiterTracker T(*this, tok::l_paren);
if (T.expectAndConsume(diag::err_expected_lparen_after, CastName))
return ExprError();
ExprResult Result = ParseExpression();
// Match the ')'.
T.consumeClose();
if (!Result.isInvalid() && !DeclaratorInfo.isInvalidType())
Result = Actions.ActOnCXXNamedCast(OpLoc, Kind,
LAngleBracketLoc, DeclaratorInfo,
RAngleBracketLoc,
T.getOpenLocation(), Result.get(),
T.getCloseLocation());
return Result;
}
/// ParseCXXTypeid - This handles the C++ typeid expression.
///
/// postfix-expression: [C++ 5.2p1]
/// 'typeid' '(' expression ')'
/// 'typeid' '(' type-id ')'
///
ExprResult Parser::ParseCXXTypeid() {
assert(Tok.is(tok::kw_typeid) && "Not 'typeid'!");
SourceLocation OpLoc = ConsumeToken();
SourceLocation LParenLoc, RParenLoc;
BalancedDelimiterTracker T(*this, tok::l_paren);
// typeid expressions are always parenthesized.
if (T.expectAndConsume(diag::err_expected_lparen_after, "typeid"))
return ExprError();
LParenLoc = T.getOpenLocation();
ExprResult Result;
// C++0x [expr.typeid]p3:
// When typeid is applied to an expression other than an lvalue of a
// polymorphic class type [...] The expression is an unevaluated
// operand (Clause 5).
//
// Note that we can't tell whether the expression is an lvalue of a
// polymorphic class type until after we've parsed the expression; we
// speculatively assume the subexpression is unevaluated, and fix it up
// later.
//
// We enter the unevaluated context before trying to determine whether we
// have a type-id, because the tentative parse logic will try to resolve
// names, and must treat them as unevaluated.
EnterExpressionEvaluationContext Unevaluated(
Actions, Sema::ExpressionEvaluationContext::Unevaluated,
Sema::ReuseLambdaContextDecl);
if (isTypeIdInParens()) {
TypeResult Ty = ParseTypeName();
// Match the ')'.
T.consumeClose();
RParenLoc = T.getCloseLocation();
if (Ty.isInvalid() || RParenLoc.isInvalid())
return ExprError();
Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/true,
Ty.get().getAsOpaquePtr(), RParenLoc);
} else {
Result = ParseExpression();
// Match the ')'.
if (Result.isInvalid())
SkipUntil(tok::r_paren, StopAtSemi);
else {
T.consumeClose();
RParenLoc = T.getCloseLocation();
if (RParenLoc.isInvalid())
return ExprError();
Result = Actions.ActOnCXXTypeid(OpLoc, LParenLoc, /*isType=*/false,
Result.get(), RParenLoc);
}
}
return Result;
}
/// ParseCXXUuidof - This handles the Microsoft C++ __uuidof expression.
///
/// '__uuidof' '(' expression ')'
/// '__uuidof' '(' type-id ')'
///
ExprResult Parser::ParseCXXUuidof() {
assert(Tok.is(tok::kw___uuidof) && "Not '__uuidof'!");
SourceLocation OpLoc = ConsumeToken();
BalancedDelimiterTracker T(*this, tok::l_paren);
// __uuidof expressions are always parenthesized.
if (T.expectAndConsume(diag::err_expected_lparen_after, "__uuidof"))
return ExprError();
ExprResult Result;
if (isTypeIdInParens()) {
TypeResult Ty = ParseTypeName();
// Match the ')'.
T.consumeClose();
if (Ty.isInvalid())
return ExprError();
Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(), /*isType=*/true,
Ty.get().getAsOpaquePtr(),
T.getCloseLocation());
} else {
EnterExpressionEvaluationContext Unevaluated(
Actions, Sema::ExpressionEvaluationContext::Unevaluated);
Result = ParseExpression();
// Match the ')'.
if (Result.isInvalid())
SkipUntil(tok::r_paren, StopAtSemi);
else {
T.consumeClose();
Result = Actions.ActOnCXXUuidof(OpLoc, T.getOpenLocation(),
/*isType=*/false,
Result.get(), T.getCloseLocation());
}
}
return Result;
}
/// Parse a C++ pseudo-destructor expression after the base,
/// . or -> operator, and nested-name-specifier have already been
/// parsed.
///
/// postfix-expression: [C++ 5.2]
/// postfix-expression . pseudo-destructor-name
/// postfix-expression -> pseudo-destructor-name
///
/// pseudo-destructor-name:
/// ::[opt] nested-name-specifier[opt] type-name :: ~type-name
/// ::[opt] nested-name-specifier template simple-template-id ::
/// ~type-name
/// ::[opt] nested-name-specifier[opt] ~type-name
///
ExprResult
Parser::ParseCXXPseudoDestructor(Expr *Base, SourceLocation OpLoc,
tok::TokenKind OpKind,
CXXScopeSpec &SS,
ParsedType ObjectType) {
// We're parsing either a pseudo-destructor-name or a dependent
// member access that has the same form as a
// pseudo-destructor-name. We parse both in the same way and let
// the action model sort them out.
//
// Note that the ::[opt] nested-name-specifier[opt] has already
// been parsed, and if there was a simple-template-id, it has
// been coalesced into a template-id annotation token.
UnqualifiedId FirstTypeName;
SourceLocation CCLoc;
if (Tok.is(tok::identifier)) {
FirstTypeName.setIdentifier(Tok.getIdentifierInfo(), Tok.getLocation());
ConsumeToken();
assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
CCLoc = ConsumeToken();
} else if (Tok.is(tok::annot_template_id)) {
// FIXME: retrieve TemplateKWLoc from template-id annotation and
// store it in the pseudo-dtor node (to be used when instantiating it).
FirstTypeName.setTemplateId(
(TemplateIdAnnotation *)Tok.getAnnotationValue());
ConsumeAnnotationToken();
assert(Tok.is(tok::coloncolon) &&"ParseOptionalCXXScopeSpecifier fail");
CCLoc = ConsumeToken();
} else {
FirstTypeName.setIdentifier(nullptr, SourceLocation());
}
// Parse the tilde.
assert(Tok.is(tok::tilde) && "ParseOptionalCXXScopeSpecifier fail");
SourceLocation TildeLoc = ConsumeToken();
if (Tok.is(tok::kw_decltype) && !FirstTypeName.isValid() && SS.isEmpty()) {
DeclSpec DS(AttrFactory);
ParseDecltypeSpecifier(DS);
if (DS.getTypeSpecType() == TST_error)
return ExprError();
return Actions.ActOnPseudoDestructorExpr(getCurScope(), Base, OpLoc, OpKind,
TildeLoc, DS);
}
if (!Tok.is(tok::identifier)) {
Diag(Tok, diag::err_destructor_tilde_identifier);
return ExprError();
}
// Parse the second type.
UnqualifiedId SecondTypeName;
IdentifierInfo *Name = Tok.getIdentifierInfo();
SourceLocation NameLoc = ConsumeToken();
SecondTypeName.setIdentifier(Name, NameLoc);
// If there is a '<', the second type name is a template-id. Parse
// it as such.
if (Tok.is(tok::less) &&
ParseUnqualifiedIdTemplateId(SS, SourceLocation(),
Name, NameLoc,
false, ObjectType, SecondTypeName,
/*AssumeTemplateName=*/true))
return ExprError();
return Actions.ActOnPseudoDestructorExpr(getCurScope(), Base, OpLoc, OpKind,
SS, FirstTypeName, CCLoc, TildeLoc,
SecondTypeName);
}
/// ParseCXXBoolLiteral - This handles the C++ Boolean literals.
///
/// boolean-literal: [C++ 2.13.5]
/// 'true'
/// 'false'
ExprResult Parser::ParseCXXBoolLiteral() {
tok::TokenKind Kind = Tok.getKind();
return Actions.ActOnCXXBoolLiteral(ConsumeToken(), Kind);
}
/// ParseThrowExpression - This handles the C++ throw expression.
///
/// throw-expression: [C++ 15]
/// 'throw' assignment-expression[opt]
ExprResult Parser::ParseThrowExpression() {
assert(Tok.is(tok::kw_throw) && "Not throw!");
SourceLocation ThrowLoc = ConsumeToken(); // Eat the throw token.
// If the current token isn't the start of an assignment-expression,
// then the expression is not present. This handles things like:
// "C ? throw : (void)42", which is crazy but legal.
switch (Tok.getKind()) { // FIXME: move this predicate somewhere common.
case tok::semi:
case tok::r_paren:
case tok::r_square:
case tok::r_brace:
case tok::colon:
case tok::comma:
return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, nullptr);
default:
ExprResult Expr(ParseAssignmentExpression());
if (Expr.isInvalid()) return Expr;
return Actions.ActOnCXXThrow(getCurScope(), ThrowLoc, Expr.get());
}
}
/// Parse the C++ Coroutines co_yield expression.
///
/// co_yield-expression:
/// 'co_yield' assignment-expression[opt]
ExprResult Parser::ParseCoyieldExpression() {
assert(Tok.is(tok::kw_co_yield) && "Not co_yield!");
SourceLocation Loc = ConsumeToken();
ExprResult Expr = Tok.is(tok::l_brace) ? ParseBraceInitializer()
: ParseAssignmentExpression();
if (!Expr.isInvalid())
Expr = Actions.ActOnCoyieldExpr(getCurScope(), Loc, Expr.get());
return Expr;
}
/// ParseCXXThis - This handles the C++ 'this' pointer.
///
/// C++ 9.3.2: In the body of a non-static member function, the keyword this is
/// a non-lvalue expression whose value is the address of the object for which
/// the function is called.
ExprResult Parser::ParseCXXThis() {
assert(Tok.is(tok::kw_this) && "Not 'this'!");
SourceLocation ThisLoc = ConsumeToken();
return Actions.ActOnCXXThis(ThisLoc);
}
/// ParseCXXTypeConstructExpression - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
/// See [C++ 5.2.3].
///
/// postfix-expression: [C++ 5.2p1]
/// simple-type-specifier '(' expression-list[opt] ')'
/// [C++0x] simple-type-specifier braced-init-list
/// typename-specifier '(' expression-list[opt] ')'
/// [C++0x] typename-specifier braced-init-list
///
/// In C++1z onwards, the type specifier can also be a template-name.
ExprResult
Parser::ParseCXXTypeConstructExpression(const DeclSpec &DS) {
Declarator DeclaratorInfo(DS, DeclaratorContext::FunctionalCastContext);
ParsedType TypeRep = Actions.ActOnTypeName(getCurScope(), DeclaratorInfo).get();
assert((Tok.is(tok::l_paren) ||
(getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)))
&& "Expected '(' or '{'!");
if (Tok.is(tok::l_brace)) {
ExprResult Init = ParseBraceInitializer();
if (Init.isInvalid())
return Init;
Expr *InitList = Init.get();
return Actions.ActOnCXXTypeConstructExpr(
TypeRep, InitList->getBeginLoc(), MultiExprArg(&InitList, 1),
InitList->getEndLoc(), /*ListInitialization=*/true);
} else {
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
PreferredType.enterTypeCast(Tok.getLocation(), TypeRep.get());
ExprVector Exprs;
CommaLocsTy CommaLocs;
auto RunSignatureHelp = [&]() {
QualType PreferredType = Actions.ProduceConstructorSignatureHelp(
getCurScope(), TypeRep.get()->getCanonicalTypeInternal(),
DS.getEndLoc(), Exprs, T.getOpenLocation());
CalledSignatureHelp = true;
return PreferredType;
};
if (Tok.isNot(tok::r_paren)) {
if (ParseExpressionList(Exprs, CommaLocs, [&] {
PreferredType.enterFunctionArgument(Tok.getLocation(),
RunSignatureHelp);
})) {
if (PP.isCodeCompletionReached() && !CalledSignatureHelp)
RunSignatureHelp();
SkipUntil(tok::r_paren, StopAtSemi);
return ExprError();
}
}
// Match the ')'.
T.consumeClose();
// TypeRep could be null, if it references an invalid typedef.
if (!TypeRep)
return ExprError();
assert((Exprs.size() == 0 || Exprs.size()-1 == CommaLocs.size())&&
"Unexpected number of commas!");
return Actions.ActOnCXXTypeConstructExpr(TypeRep, T.getOpenLocation(),
Exprs, T.getCloseLocation(),
/*ListInitialization=*/false);
}
}
/// ParseCXXCondition - if/switch/while condition expression.
///
/// condition:
/// expression
/// type-specifier-seq declarator '=' assignment-expression
/// [C++11] type-specifier-seq declarator '=' initializer-clause
/// [C++11] type-specifier-seq declarator braced-init-list
/// [Clang] type-specifier-seq ref-qualifier[opt] '[' identifier-list ']'
/// brace-or-equal-initializer
/// [GNU] type-specifier-seq declarator simple-asm-expr[opt] attributes[opt]
/// '=' assignment-expression
///
/// In C++1z, a condition may in some contexts be preceded by an
/// optional init-statement. This function will parse that too.
///
/// \param InitStmt If non-null, an init-statement is permitted, and if present
/// will be parsed and stored here.
///
/// \param Loc The location of the start of the statement that requires this
/// condition, e.g., the "for" in a for loop.
///
/// \param FRI If non-null, a for range declaration is permitted, and if
/// present will be parsed and stored here, and a null result will be returned.
///
/// \returns The parsed condition.
Sema::ConditionResult Parser::ParseCXXCondition(StmtResult *InitStmt,
SourceLocation Loc,
Sema::ConditionKind CK,
ForRangeInfo *FRI) {
ParenBraceBracketBalancer BalancerRAIIObj(*this);
PreferredType.enterCondition(Actions, Tok.getLocation());
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Condition);
cutOffParsing();
return Sema::ConditionError();
}
ParsedAttributesWithRange attrs(AttrFactory);
MaybeParseCXX11Attributes(attrs);
const auto WarnOnInit = [this, &CK] {
Diag(Tok.getLocation(), getLangOpts().CPlusPlus17
? diag::warn_cxx14_compat_init_statement
: diag::ext_init_statement)
<< (CK == Sema::ConditionKind::Switch);
};
// Determine what kind of thing we have.
switch (isCXXConditionDeclarationOrInitStatement(InitStmt, FRI)) {
case ConditionOrInitStatement::Expression: {
ProhibitAttributes(attrs);
// We can have an empty expression here.
// if (; true);
if (InitStmt && Tok.is(tok::semi)) {
WarnOnInit();
SourceLocation SemiLoc = Tok.getLocation();
if (!Tok.hasLeadingEmptyMacro() && !SemiLoc.isMacroID()) {
Diag(SemiLoc, diag::warn_empty_init_statement)
<< (CK == Sema::ConditionKind::Switch)
<< FixItHint::CreateRemoval(SemiLoc);
}
ConsumeToken();
*InitStmt = Actions.ActOnNullStmt(SemiLoc);
return ParseCXXCondition(nullptr, Loc, CK);
}
// Parse the expression.
ExprResult Expr = ParseExpression(); // expression
if (Expr.isInvalid())
return Sema::ConditionError();
if (InitStmt && Tok.is(tok::semi)) {
WarnOnInit();
*InitStmt = Actions.ActOnExprStmt(Expr.get());
ConsumeToken();
return ParseCXXCondition(nullptr, Loc, CK);
}
return Actions.ActOnCondition(getCurScope(), Loc, Expr.get(), CK);
}
case ConditionOrInitStatement::InitStmtDecl: {
WarnOnInit();
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy DG =
ParseSimpleDeclaration(DeclaratorContext::InitStmtContext, DeclEnd,
attrs, /*RequireSemi=*/true);
*InitStmt = Actions.ActOnDeclStmt(DG, DeclStart, DeclEnd);
return ParseCXXCondition(nullptr, Loc, CK);
}
case ConditionOrInitStatement::ForRangeDecl: {
assert(FRI && "should not parse a for range declaration here");
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy DG = ParseSimpleDeclaration(
DeclaratorContext::ForContext, DeclEnd, attrs, false, FRI);
FRI->LoopVar = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
return Sema::ConditionResult();
}
case ConditionOrInitStatement::ConditionDecl:
case ConditionOrInitStatement::Error:
break;
}
// type-specifier-seq
DeclSpec DS(AttrFactory);
DS.takeAttributesFrom(attrs);
ParseSpecifierQualifierList(DS, AS_none, DeclSpecContext::DSC_condition);
// declarator
Declarator DeclaratorInfo(DS, DeclaratorContext::ConditionContext);
ParseDeclarator(DeclaratorInfo);
// simple-asm-expr[opt]
if (Tok.is(tok::kw_asm)) {
SourceLocation Loc;
ExprResult AsmLabel(ParseSimpleAsm(&Loc));
if (AsmLabel.isInvalid()) {
SkipUntil(tok::semi, StopAtSemi);
return Sema::ConditionError();
}
DeclaratorInfo.setAsmLabel(AsmLabel.get());
DeclaratorInfo.SetRangeEnd(Loc);
}
// If attributes are present, parse them.
MaybeParseGNUAttributes(DeclaratorInfo);
// Type-check the declaration itself.
DeclResult Dcl = Actions.ActOnCXXConditionDeclaration(getCurScope(),
DeclaratorInfo);
if (Dcl.isInvalid())
return Sema::ConditionError();
Decl *DeclOut = Dcl.get();
// '=' assignment-expression
// If a '==' or '+=' is found, suggest a fixit to '='.
bool CopyInitialization = isTokenEqualOrEqualTypo();
if (CopyInitialization)
ConsumeToken();
ExprResult InitExpr = ExprError();
if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace)) {
Diag(Tok.getLocation(),
diag::warn_cxx98_compat_generalized_initializer_lists);
InitExpr = ParseBraceInitializer();
} else if (CopyInitialization) {
PreferredType.enterVariableInit(Tok.getLocation(), DeclOut);
InitExpr = ParseAssignmentExpression();
} else if (Tok.is(tok::l_paren)) {
// This was probably an attempt to initialize the variable.
SourceLocation LParen = ConsumeParen(), RParen = LParen;
if (SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch))
RParen = ConsumeParen();
Diag(DeclOut->getLocation(),
diag::err_expected_init_in_condition_lparen)
<< SourceRange(LParen, RParen);
} else {
Diag(DeclOut->getLocation(), diag::err_expected_init_in_condition);
}
if (!InitExpr.isInvalid())
Actions.AddInitializerToDecl(DeclOut, InitExpr.get(), !CopyInitialization);
else
Actions.ActOnInitializerError(DeclOut);
Actions.FinalizeDeclaration(DeclOut);
return Actions.ActOnConditionVariable(DeclOut, Loc, CK);
}
/// ParseCXXSimpleTypeSpecifier - [C++ 7.1.5.2] Simple type specifiers.
/// This should only be called when the current token is known to be part of
/// simple-type-specifier.
///
/// simple-type-specifier:
/// '::'[opt] nested-name-specifier[opt] type-name
/// '::'[opt] nested-name-specifier 'template' simple-template-id [TODO]
/// char
/// wchar_t
/// bool
/// short
/// int
/// long
/// signed
/// unsigned
/// float
/// double
/// void
/// [GNU] typeof-specifier
/// [C++0x] auto [TODO]
///
/// type-name:
/// class-name
/// enum-name
/// typedef-name
///
void Parser::ParseCXXSimpleTypeSpecifier(DeclSpec &DS) {
DS.SetRangeStart(Tok.getLocation());
const char *PrevSpec;
unsigned DiagID;
SourceLocation Loc = Tok.getLocation();
const clang::PrintingPolicy &Policy =
Actions.getASTContext().getPrintingPolicy();
switch (Tok.getKind()) {
case tok::identifier: // foo::bar
case tok::coloncolon: // ::foo::bar
llvm_unreachable("Annotation token should already be formed!");
default:
llvm_unreachable("Not a simple-type-specifier token!");
// type-name
case tok::annot_typename: {
if (getTypeAnnotation(Tok))
DS.SetTypeSpecType(DeclSpec::TST_typename, Loc, PrevSpec, DiagID,
getTypeAnnotation(Tok), Policy);
else
DS.SetTypeSpecError();
DS.SetRangeEnd(Tok.getAnnotationEndLoc());
ConsumeAnnotationToken();
DS.Finish(Actions, Policy);
return;
}
// builtin types
case tok::kw_short:
DS.SetTypeSpecWidth(DeclSpec::TSW_short, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_long:
DS.SetTypeSpecWidth(DeclSpec::TSW_long, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw___int64:
DS.SetTypeSpecWidth(DeclSpec::TSW_longlong, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_signed:
DS.SetTypeSpecSign(DeclSpec::TSS_signed, Loc, PrevSpec, DiagID);
break;
case tok::kw_unsigned:
DS.SetTypeSpecSign(DeclSpec::TSS_unsigned, Loc, PrevSpec, DiagID);
break;
case tok::kw_void:
DS.SetTypeSpecType(DeclSpec::TST_void, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_char:
DS.SetTypeSpecType(DeclSpec::TST_char, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_int:
DS.SetTypeSpecType(DeclSpec::TST_int, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw___int128:
DS.SetTypeSpecType(DeclSpec::TST_int128, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_half:
DS.SetTypeSpecType(DeclSpec::TST_half, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_float:
DS.SetTypeSpecType(DeclSpec::TST_float, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_double:
DS.SetTypeSpecType(DeclSpec::TST_double, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw__Float16:
DS.SetTypeSpecType(DeclSpec::TST_float16, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw___float128:
DS.SetTypeSpecType(DeclSpec::TST_float128, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_wchar_t:
DS.SetTypeSpecType(DeclSpec::TST_wchar, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_char8_t:
DS.SetTypeSpecType(DeclSpec::TST_char8, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_char16_t:
DS.SetTypeSpecType(DeclSpec::TST_char16, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_char32_t:
DS.SetTypeSpecType(DeclSpec::TST_char32, Loc, PrevSpec, DiagID, Policy);
break;
case tok::kw_bool:
DS.SetTypeSpecType(DeclSpec::TST_bool, Loc, PrevSpec, DiagID, Policy);
break;
#define GENERIC_IMAGE_TYPE(ImgType, Id) \
case tok::kw_##ImgType##_t: \
DS.SetTypeSpecType(DeclSpec::TST_##ImgType##_t, Loc, PrevSpec, DiagID, \
Policy); \
break;
#include "clang/Basic/OpenCLImageTypes.def"
case tok::annot_decltype:
case tok::kw_decltype:
DS.SetRangeEnd(ParseDecltypeSpecifier(DS));
return DS.Finish(Actions, Policy);
// GNU typeof support.
case tok::kw_typeof:
ParseTypeofSpecifier(DS);
DS.Finish(Actions, Policy);
return;
}
ConsumeAnyToken();
DS.SetRangeEnd(PrevTokLocation);
DS.Finish(Actions, Policy);
}
/// ParseCXXTypeSpecifierSeq - Parse a C++ type-specifier-seq (C++
/// [dcl.name]), which is a non-empty sequence of type-specifiers,
/// e.g., "const short int". Note that the DeclSpec is *not* finished
/// by parsing the type-specifier-seq, because these sequences are
/// typically followed by some form of declarator. Returns true and
/// emits diagnostics if this is not a type-specifier-seq, false
/// otherwise.
///
/// type-specifier-seq: [C++ 8.1]
/// type-specifier type-specifier-seq[opt]
///
bool Parser::ParseCXXTypeSpecifierSeq(DeclSpec &DS) {
ParseSpecifierQualifierList(DS, AS_none, DeclSpecContext::DSC_type_specifier);
DS.Finish(Actions, Actions.getASTContext().getPrintingPolicy());
return false;
}
/// Finish parsing a C++ unqualified-id that is a template-id of
/// some form.
///
/// This routine is invoked when a '<' is encountered after an identifier or
/// operator-function-id is parsed by \c ParseUnqualifiedId() to determine
/// whether the unqualified-id is actually a template-id. This routine will
/// then parse the template arguments and form the appropriate template-id to
/// return to the caller.
///
/// \param SS the nested-name-specifier that precedes this template-id, if
/// we're actually parsing a qualified-id.
///
/// \param Name for constructor and destructor names, this is the actual
/// identifier that may be a template-name.
///
/// \param NameLoc the location of the class-name in a constructor or
/// destructor.
///
/// \param EnteringContext whether we're entering the scope of the
/// nested-name-specifier.
///
/// \param ObjectType if this unqualified-id occurs within a member access
/// expression, the type of the base object whose member is being accessed.
///
/// \param Id as input, describes the template-name or operator-function-id
/// that precedes the '<'. If template arguments were parsed successfully,
/// will be updated with the template-id.
///
/// \param AssumeTemplateId When true, this routine will assume that the name
/// refers to a template without performing name lookup to verify.
///
/// \returns true if a parse error occurred, false otherwise.
bool Parser::ParseUnqualifiedIdTemplateId(CXXScopeSpec &SS,
SourceLocation TemplateKWLoc,
IdentifierInfo *Name,
SourceLocation NameLoc,
bool EnteringContext,
ParsedType ObjectType,
UnqualifiedId &Id,
bool AssumeTemplateId) {
assert(Tok.is(tok::less) && "Expected '<' to finish parsing a template-id");
TemplateTy Template;
TemplateNameKind TNK = TNK_Non_template;
switch (Id.getKind()) {
case UnqualifiedIdKind::IK_Identifier:
case UnqualifiedIdKind::IK_OperatorFunctionId:
case UnqualifiedIdKind::IK_LiteralOperatorId:
if (AssumeTemplateId) {
// We defer the injected-class-name checks until we've found whether
// this template-id is used to form a nested-name-specifier or not.
TNK = Actions.ActOnDependentTemplateName(
getCurScope(), SS, TemplateKWLoc, Id, ObjectType, EnteringContext,
Template, /*AllowInjectedClassName*/ true);
if (TNK == TNK_Non_template)
return true;
} else {
bool MemberOfUnknownSpecialization;
TNK = Actions.isTemplateName(getCurScope(), SS,
TemplateKWLoc.isValid(), Id,
ObjectType, EnteringContext, Template,
MemberOfUnknownSpecialization);
// If lookup found nothing but we're assuming that this is a template
// name, double-check that makes sense syntactically before committing
// to it.
if (TNK == TNK_Undeclared_template &&
isTemplateArgumentList(0) == TPResult::False)
return false;
if (TNK == TNK_Non_template && MemberOfUnknownSpecialization &&
ObjectType && isTemplateArgumentList(0) == TPResult::True) {
// We have something like t->getAs<T>(), where getAs is a
// member of an unknown specialization. However, this will only
// parse correctly as a template, so suggest the keyword 'template'
// before 'getAs' and treat this as a dependent template name.
std::string Name;
if (Id.getKind() == UnqualifiedIdKind::IK_Identifier)
Name = Id.Identifier->getName();
else {
Name = "operator ";
if (Id.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId)
Name += getOperatorSpelling(Id.OperatorFunctionId.Operator);
else
Name += Id.Identifier->getName();
}
Diag(Id.StartLocation, diag::err_missing_dependent_template_keyword)
<< Name
<< FixItHint::CreateInsertion(Id.StartLocation, "template ");
TNK = Actions.ActOnDependentTemplateName(
getCurScope(), SS, TemplateKWLoc, Id, ObjectType, EnteringContext,
Template, /*AllowInjectedClassName*/ true);
if (TNK == TNK_Non_template)
return true;
}
}
break;
case UnqualifiedIdKind::IK_ConstructorName: {
UnqualifiedId TemplateName;
bool MemberOfUnknownSpecialization;
TemplateName.setIdentifier(Name, NameLoc);
TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
TemplateName, ObjectType,
EnteringContext, Template,
MemberOfUnknownSpecialization);
break;
}
case UnqualifiedIdKind::IK_DestructorName: {
UnqualifiedId TemplateName;
bool MemberOfUnknownSpecialization;
TemplateName.setIdentifier(Name, NameLoc);
if (ObjectType) {
TNK = Actions.ActOnDependentTemplateName(
getCurScope(), SS, TemplateKWLoc, TemplateName, ObjectType,
EnteringContext, Template, /*AllowInjectedClassName*/ true);
if (TNK == TNK_Non_template)
return true;
} else {
TNK = Actions.isTemplateName(getCurScope(), SS, TemplateKWLoc.isValid(),
TemplateName, ObjectType,
EnteringContext, Template,
MemberOfUnknownSpecialization);
if (TNK == TNK_Non_template && !Id.DestructorName.get()) {
Diag(NameLoc, diag::err_destructor_template_id)
<< Name << SS.getRange();
return true;
}
}
break;
}
default:
return false;
}
if (TNK == TNK_Non_template)
return false;
// Parse the enclosed template argument list.
SourceLocation LAngleLoc, RAngleLoc;
TemplateArgList TemplateArgs;
if (ParseTemplateIdAfterTemplateName(true, LAngleLoc, TemplateArgs,
RAngleLoc))
return true;
if (Id.getKind() == UnqualifiedIdKind::IK_Identifier ||
Id.getKind() == UnqualifiedIdKind::IK_OperatorFunctionId ||
Id.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId) {
// Form a parsed representation of the template-id to be stored in the
// UnqualifiedId.
// FIXME: Store name for literal operator too.
IdentifierInfo *TemplateII =
Id.getKind() == UnqualifiedIdKind::IK_Identifier ? Id.Identifier
: nullptr;
OverloadedOperatorKind OpKind =
Id.getKind() == UnqualifiedIdKind::IK_Identifier
? OO_None
: Id.OperatorFunctionId.Operator;
TemplateIdAnnotation *TemplateId = TemplateIdAnnotation::Create(
SS, TemplateKWLoc, Id.StartLocation, TemplateII, OpKind, Template, TNK,
LAngleLoc, RAngleLoc, TemplateArgs, TemplateIds);
Id.setTemplateId(TemplateId);
return false;
}
// Bundle the template arguments together.
ASTTemplateArgsPtr TemplateArgsPtr(TemplateArgs);
// Constructor and destructor names.
TypeResult Type = Actions.ActOnTemplateIdType(
getCurScope(), SS, TemplateKWLoc, Template, Name, NameLoc, LAngleLoc,
TemplateArgsPtr, RAngleLoc, /*IsCtorOrDtorName=*/true);
if (Type.isInvalid())
return true;
if (Id.getKind() == UnqualifiedIdKind::IK_ConstructorName)
Id.setConstructorName(Type.get(), NameLoc, RAngleLoc);
else
Id.setDestructorName(Id.StartLocation, Type.get(), RAngleLoc);
return false;
}
/// Parse an operator-function-id or conversion-function-id as part
/// of a C++ unqualified-id.
///
/// This routine is responsible only for parsing the operator-function-id or
/// conversion-function-id; it does not handle template arguments in any way.
///
/// \code
/// operator-function-id: [C++ 13.5]
/// 'operator' operator
///
/// operator: one of
/// new delete new[] delete[]
/// + - * / % ^ & | ~
/// ! = < > += -= *= /= %=
/// ^= &= |= << >> >>= <<= == !=
/// <= >= && || ++ -- , ->* ->
/// () [] <=>
///
/// conversion-function-id: [C++ 12.3.2]
/// operator conversion-type-id
///
/// conversion-type-id:
/// type-specifier-seq conversion-declarator[opt]
///
/// conversion-declarator:
/// ptr-operator conversion-declarator[opt]
/// \endcode
///
/// \param SS The nested-name-specifier that preceded this unqualified-id. If
/// non-empty, then we are parsing the unqualified-id of a qualified-id.
///
/// \param EnteringContext whether we are entering the scope of the
/// nested-name-specifier.
///
/// \param ObjectType if this unqualified-id occurs within a member access
/// expression, the type of the base object whose member is being accessed.
///
/// \param Result on a successful parse, contains the parsed unqualified-id.
///
/// \returns true if parsing fails, false otherwise.
bool Parser::ParseUnqualifiedIdOperator(CXXScopeSpec &SS, bool EnteringContext,
ParsedType ObjectType,
UnqualifiedId &Result) {
assert(Tok.is(tok::kw_operator) && "Expected 'operator' keyword");
// Consume the 'operator' keyword.
SourceLocation KeywordLoc = ConsumeToken();
// Determine what kind of operator name we have.
unsigned SymbolIdx = 0;
SourceLocation SymbolLocations[3];
OverloadedOperatorKind Op = OO_None;
switch (Tok.getKind()) {
case tok::kw_new:
case tok::kw_delete: {
bool isNew = Tok.getKind() == tok::kw_new;
// Consume the 'new' or 'delete'.
SymbolLocations[SymbolIdx++] = ConsumeToken();
// Check for array new/delete.
if (Tok.is(tok::l_square) &&
(!getLangOpts().CPlusPlus11 || NextToken().isNot(tok::l_square))) {
// Consume the '[' and ']'.
BalancedDelimiterTracker T(*this, tok::l_square);
T.consumeOpen();
T.consumeClose();
if (T.getCloseLocation().isInvalid())
return true;
SymbolLocations[SymbolIdx++] = T.getOpenLocation();
SymbolLocations[SymbolIdx++] = T.getCloseLocation();
Op = isNew? OO_Array_New : OO_Array_Delete;
} else {
Op = isNew? OO_New : OO_Delete;
}
break;
}
#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
case tok::Token: \
SymbolLocations[SymbolIdx++] = ConsumeToken(); \
Op = OO_##Name; \
break;
#define OVERLOADED_OPERATOR_MULTI(Name,Spelling,Unary,Binary,MemberOnly)
#include "clang/Basic/OperatorKinds.def"
case tok::l_paren: {
// Consume the '(' and ')'.
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
T.consumeClose();
if (T.getCloseLocation().isInvalid())
return true;
SymbolLocations[SymbolIdx++] = T.getOpenLocation();
SymbolLocations[SymbolIdx++] = T.getCloseLocation();
Op = OO_Call;
break;
}
case tok::l_square: {
// Consume the '[' and ']'.
BalancedDelimiterTracker T(*this, tok::l_square);
T.consumeOpen();
T.consumeClose();
if (T.getCloseLocation().isInvalid())
return true;
SymbolLocations[SymbolIdx++] = T.getOpenLocation();
SymbolLocations[SymbolIdx++] = T.getCloseLocation();
Op = OO_Subscript;
break;
}
case tok::code_completion: {
// Code completion for the operator name.
Actions.CodeCompleteOperatorName(getCurScope());
cutOffParsing();
// Don't try to parse any further.
return true;
}
default:
break;
}
if (Op != OO_None) {
// We have parsed an operator-function-id.
Result.setOperatorFunctionId(KeywordLoc, Op, SymbolLocations);
return false;
}
// Parse a literal-operator-id.
//
// literal-operator-id: C++11 [over.literal]
// operator string-literal identifier
// operator user-defined-string-literal
if (getLangOpts().CPlusPlus11 && isTokenStringLiteral()) {
Diag(Tok.getLocation(), diag::warn_cxx98_compat_literal_operator);
SourceLocation DiagLoc;
unsigned DiagId = 0;
// We're past translation phase 6, so perform string literal concatenation
// before checking for "".
SmallVector<Token, 4> Toks;
SmallVector<SourceLocation, 4> TokLocs;
while (isTokenStringLiteral()) {
if (!Tok.is(tok::string_literal) && !DiagId) {
// C++11 [over.literal]p1:
// The string-literal or user-defined-string-literal in a
// literal-operator-id shall have no encoding-prefix [...].
DiagLoc = Tok.getLocation();
DiagId = diag::err_literal_operator_string_prefix;
}
Toks.push_back(Tok);
TokLocs.push_back(ConsumeStringToken());
}
StringLiteralParser Literal(Toks, PP);
if (Literal.hadError)
return true;
// Grab the literal operator's suffix, which will be either the next token
// or a ud-suffix from the string literal.
IdentifierInfo *II = nullptr;
SourceLocation SuffixLoc;
if (!Literal.getUDSuffix().empty()) {
II = &PP.getIdentifierTable().get(Literal.getUDSuffix());
SuffixLoc =
Lexer::AdvanceToTokenCharacter(TokLocs[Literal.getUDSuffixToken()],
Literal.getUDSuffixOffset(),
PP.getSourceManager(), getLangOpts());
} else if (Tok.is(tok::identifier)) {
II = Tok.getIdentifierInfo();
SuffixLoc = ConsumeToken();
TokLocs.push_back(SuffixLoc);
} else {
Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
return true;
}
// The string literal must be empty.
if (!Literal.GetString().empty() || Literal.Pascal) {
// C++11 [over.literal]p1:
// The string-literal or user-defined-string-literal in a
// literal-operator-id shall [...] contain no characters
// other than the implicit terminating '\0'.
DiagLoc = TokLocs.front();
DiagId = diag::err_literal_operator_string_not_empty;
}
if (DiagId) {
// This isn't a valid literal-operator-id, but we think we know
// what the user meant. Tell them what they should have written.
SmallString<32> Str;
Str += "\"\"";
Str += II->getName();
Diag(DiagLoc, DiagId) << FixItHint::CreateReplacement(
SourceRange(TokLocs.front(), TokLocs.back()), Str);
}
Result.setLiteralOperatorId(II, KeywordLoc, SuffixLoc);
return Actions.checkLiteralOperatorId(SS, Result);
}
// Parse a conversion-function-id.
//
// conversion-function-id: [C++ 12.3.2]
// operator conversion-type-id
//
// conversion-type-id:
// type-specifier-seq conversion-declarator[opt]
//
// conversion-declarator:
// ptr-operator conversion-declarator[opt]
// Parse the type-specifier-seq.
DeclSpec DS(AttrFactory);
if (ParseCXXTypeSpecifierSeq(DS)) // FIXME: ObjectType?
return true;
// Parse the conversion-declarator, which is merely a sequence of
// ptr-operators.
Declarator D(DS, DeclaratorContext::ConversionIdContext);
ParseDeclaratorInternal(D, /*DirectDeclParser=*/nullptr);
// Finish up the type.
TypeResult Ty = Actions.ActOnTypeName(getCurScope(), D);
if (Ty.isInvalid())
return true;
// Note that this is a conversion-function-id.
Result.setConversionFunctionId(KeywordLoc, Ty.get(),
D.getSourceRange().getEnd());
return false;
}
/// Parse a C++ unqualified-id (or a C identifier), which describes the
/// name of an entity.
///
/// \code
/// unqualified-id: [C++ expr.prim.general]
/// identifier
/// operator-function-id
/// conversion-function-id
/// [C++0x] literal-operator-id [TODO]
/// ~ class-name
/// template-id
///
/// \endcode
///
/// \param SS The nested-name-specifier that preceded this unqualified-id. If
/// non-empty, then we are parsing the unqualified-id of a qualified-id.