blob: 71d19613a7efcbe79034362d6231210af0be3673 [file] [log] [blame]
//===--- ParseTentative.cpp - Ambiguity Resolution Parsing ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the tentative parsing portions of the Parser
// interfaces, for ambiguity resolution.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "clang/Parse/ParseDiagnostic.h"
#include "clang/Sema/ParsedTemplate.h"
using namespace clang;
/// isCXXDeclarationStatement - C++-specialized function that disambiguates
/// between a declaration or an expression statement, when parsing function
/// bodies. Returns true for declaration, false for expression.
///
/// declaration-statement:
/// block-declaration
///
/// block-declaration:
/// simple-declaration
/// asm-definition
/// namespace-alias-definition
/// using-declaration
/// using-directive
/// [C++0x] static_assert-declaration
///
/// asm-definition:
/// 'asm' '(' string-literal ')' ';'
///
/// namespace-alias-definition:
/// 'namespace' identifier = qualified-namespace-specifier ';'
///
/// using-declaration:
/// 'using' typename[opt] '::'[opt] nested-name-specifier
/// unqualified-id ';'
/// 'using' '::' unqualified-id ;
///
/// using-directive:
/// 'using' 'namespace' '::'[opt] nested-name-specifier[opt]
/// namespace-name ';'
///
bool Parser::isCXXDeclarationStatement() {
switch (Tok.getKind()) {
// asm-definition
case tok::kw_asm:
// namespace-alias-definition
case tok::kw_namespace:
// using-declaration
// using-directive
case tok::kw_using:
// static_assert-declaration
case tok::kw_static_assert:
case tok::kw__Static_assert:
return true;
// simple-declaration
default:
return isCXXSimpleDeclaration(/*AllowForRangeDecl=*/false);
}
}
/// isCXXSimpleDeclaration - C++-specialized function that disambiguates
/// between a simple-declaration or an expression-statement.
/// If during the disambiguation process a parsing error is encountered,
/// the function returns true to let the declaration parsing code handle it.
/// Returns false if the statement is disambiguated as expression.
///
/// simple-declaration:
/// decl-specifier-seq init-declarator-list[opt] ';'
///
/// (if AllowForRangeDecl specified)
/// for ( for-range-declaration : for-range-initializer ) statement
/// for-range-declaration:
/// attribute-specifier-seqopt type-specifier-seq declarator
bool Parser::isCXXSimpleDeclaration(bool AllowForRangeDecl) {
// C++ 6.8p1:
// There is an ambiguity in the grammar involving expression-statements and
// declarations: An expression-statement with a function-style explicit type
// conversion (5.2.3) as its leftmost subexpression can be indistinguishable
// from a declaration where the first declarator starts with a '('. In those
// cases the statement is a declaration. [Note: To disambiguate, the whole
// statement might have to be examined to determine if it is an
// expression-statement or a declaration].
// C++ 6.8p3:
// The disambiguation is purely syntactic; that is, the meaning of the names
// occurring in such a statement, beyond whether they are type-names or not,
// is not generally used in or changed by the disambiguation. Class
// templates are instantiated as necessary to determine if a qualified name
// is a type-name. Disambiguation precedes parsing, and a statement
// disambiguated as a declaration may be an ill-formed declaration.
// We don't have to parse all of the decl-specifier-seq part. There's only
// an ambiguity if the first decl-specifier is
// simple-type-specifier/typename-specifier followed by a '(', which may
// indicate a function-style cast expression.
// isCXXDeclarationSpecifier will return TPResult::Ambiguous() only in such
// a case.
bool InvalidAsDeclaration = false;
TPResult TPR = isCXXDeclarationSpecifier(TPResult::False(),
&InvalidAsDeclaration);
if (TPR != TPResult::Ambiguous())
return TPR != TPResult::False(); // Returns true for TPResult::True() or
// TPResult::Error().
// FIXME: TryParseSimpleDeclaration doesn't look past the first initializer,
// and so gets some cases wrong. We can't carry on if we've already seen
// something which makes this statement invalid as a declaration in this case,
// since it can cause us to misparse valid code. Revisit this once
// TryParseInitDeclaratorList is fixed.
if (InvalidAsDeclaration)
return false;
// FIXME: Add statistics about the number of ambiguous statements encountered
// and how they were resolved (number of declarations+number of expressions).
// Ok, we have a simple-type-specifier/typename-specifier followed by a '(',
// or an identifier which doesn't resolve as anything. We need tentative
// parsing...
TentativeParsingAction PA(*this);
TPR = TryParseSimpleDeclaration(AllowForRangeDecl);
PA.Revert();
// In case of an error, let the declaration parsing code handle it.
if (TPR == TPResult::Error())
return true;
// Declarations take precedence over expressions.
if (TPR == TPResult::Ambiguous())
TPR = TPResult::True();
assert(TPR == TPResult::True() || TPR == TPResult::False());
return TPR == TPResult::True();
}
/// Try to consume a token sequence that we've already identified as
/// (potentially) starting a decl-specifier.
Parser::TPResult Parser::TryConsumeDeclarationSpecifier() {
switch (Tok.getKind()) {
case tok::kw__Atomic:
if (NextToken().isNot(tok::l_paren)) {
ConsumeToken();
break;
}
// Fall through.
case tok::kw_typeof:
case tok::kw___attribute:
case tok::kw___underlying_type: {
ConsumeToken();
if (Tok.isNot(tok::l_paren))
return TPResult::Error();
ConsumeParen();
if (!SkipUntil(tok::r_paren))
return TPResult::Error();
break;
}
case tok::kw_class:
case tok::kw_struct:
case tok::kw_union:
case tok::kw___interface:
case tok::kw_enum:
// elaborated-type-specifier:
// class-key attribute-specifier-seq[opt]
// nested-name-specifier[opt] identifier
// class-key nested-name-specifier[opt] template[opt] simple-template-id
// enum nested-name-specifier[opt] identifier
//
// FIXME: We don't support class-specifiers nor enum-specifiers here.
ConsumeToken();
// Skip attributes.
while (Tok.is(tok::l_square) || Tok.is(tok::kw___attribute) ||
Tok.is(tok::kw___declspec) || Tok.is(tok::kw_alignas)) {
if (Tok.is(tok::l_square)) {
ConsumeBracket();
if (!SkipUntil(tok::r_square))
return TPResult::Error();
} else {
ConsumeToken();
if (Tok.isNot(tok::l_paren))
return TPResult::Error();
ConsumeParen();
if (!SkipUntil(tok::r_paren))
return TPResult::Error();
}
}
if (TryAnnotateCXXScopeToken())
return TPResult::Error();
if (Tok.is(tok::annot_cxxscope))
ConsumeToken();
if (Tok.isNot(tok::identifier) && Tok.isNot(tok::annot_template_id))
return TPResult::Error();
ConsumeToken();
break;
case tok::annot_cxxscope:
ConsumeToken();
// Fall through.
default:
ConsumeToken();
if (getLangOpts().ObjC1 && Tok.is(tok::less))
return TryParseProtocolQualifiers();
break;
}
return TPResult::Ambiguous();
}
/// simple-declaration:
/// decl-specifier-seq init-declarator-list[opt] ';'
///
/// (if AllowForRangeDecl specified)
/// for ( for-range-declaration : for-range-initializer ) statement
/// for-range-declaration:
/// attribute-specifier-seqopt type-specifier-seq declarator
///
Parser::TPResult Parser::TryParseSimpleDeclaration(bool AllowForRangeDecl) {
if (TryConsumeDeclarationSpecifier() == TPResult::Error())
return TPResult::Error();
// Two decl-specifiers in a row conclusively disambiguate this as being a
// simple-declaration. Don't bother calling isCXXDeclarationSpecifier in the
// overwhelmingly common case that the next token is a '('.
if (Tok.isNot(tok::l_paren)) {
TPResult TPR = isCXXDeclarationSpecifier();
if (TPR == TPResult::Ambiguous())
return TPResult::True();
if (TPR == TPResult::True() || TPR == TPResult::Error())
return TPR;
assert(TPR == TPResult::False());
}
TPResult TPR = TryParseInitDeclaratorList();
if (TPR != TPResult::Ambiguous())
return TPR;
if (Tok.isNot(tok::semi) && (!AllowForRangeDecl || Tok.isNot(tok::colon)))
return TPResult::False();
return TPResult::Ambiguous();
}
/// Tentatively parse an init-declarator-list in order to disambiguate it from
/// an expression.
///
/// init-declarator-list:
/// init-declarator
/// init-declarator-list ',' init-declarator
///
/// init-declarator:
/// declarator initializer[opt]
/// [GNU] declarator simple-asm-expr[opt] attributes[opt] initializer[opt]
///
/// initializer:
/// brace-or-equal-initializer
/// '(' expression-list ')'
///
/// brace-or-equal-initializer:
/// '=' initializer-clause
/// [C++11] braced-init-list
///
/// initializer-clause:
/// assignment-expression
/// braced-init-list
///
/// braced-init-list:
/// '{' initializer-list ','[opt] '}'
/// '{' '}'
///
Parser::TPResult Parser::TryParseInitDeclaratorList() {
while (1) {
// declarator
TPResult TPR = TryParseDeclarator(false/*mayBeAbstract*/);
if (TPR != TPResult::Ambiguous())
return TPR;
// [GNU] simple-asm-expr[opt] attributes[opt]
if (Tok.is(tok::kw_asm) || Tok.is(tok::kw___attribute))
return TPResult::True();
// initializer[opt]
if (Tok.is(tok::l_paren)) {
// Parse through the parens.
ConsumeParen();
if (!SkipUntil(tok::r_paren, StopAtSemi))
return TPResult::Error();
} else if (Tok.is(tok::l_brace)) {
// A left-brace here is sufficient to disambiguate the parse; an
// expression can never be followed directly by a braced-init-list.
return TPResult::True();
} else if (Tok.is(tok::equal) || isTokIdentifier_in()) {
// MSVC and g++ won't examine the rest of declarators if '=' is
// encountered; they just conclude that we have a declaration.
// EDG parses the initializer completely, which is the proper behavior
// for this case.
//
// At present, Clang follows MSVC and g++, since the parser does not have
// the ability to parse an expression fully without recording the
// results of that parse.
// FIXME: Handle this case correctly.
//
// Also allow 'in' after an Objective-C declaration as in:
// for (int (^b)(void) in array). Ideally this should be done in the
// context of parsing for-init-statement of a foreach statement only. But,
// in any other context 'in' is invalid after a declaration and parser
// issues the error regardless of outcome of this decision.
// FIXME: Change if above assumption does not hold.
return TPResult::True();
}
if (!TryConsumeToken(tok::comma))
break;
}
return TPResult::Ambiguous();
}
/// isCXXConditionDeclaration - Disambiguates between a declaration or an
/// expression for a condition of a if/switch/while/for statement.
/// If during the disambiguation process a parsing error is encountered,
/// the function returns true to let the declaration parsing code handle it.
///
/// 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
/// [GNU] type-specifier-seq declarator simple-asm-expr[opt] attributes[opt]
/// '=' assignment-expression
///
bool Parser::isCXXConditionDeclaration() {
TPResult TPR = isCXXDeclarationSpecifier();
if (TPR != TPResult::Ambiguous())
return TPR != TPResult::False(); // Returns true for TPResult::True() or
// TPResult::Error().
// FIXME: Add statistics about the number of ambiguous statements encountered
// and how they were resolved (number of declarations+number of expressions).
// Ok, we have a simple-type-specifier/typename-specifier followed by a '('.
// We need tentative parsing...
TentativeParsingAction PA(*this);
// type-specifier-seq
TryConsumeDeclarationSpecifier();
assert(Tok.is(tok::l_paren) && "Expected '('");
// declarator
TPR = TryParseDeclarator(false/*mayBeAbstract*/);
// In case of an error, let the declaration parsing code handle it.
if (TPR == TPResult::Error())
TPR = TPResult::True();
if (TPR == TPResult::Ambiguous()) {
// '='
// [GNU] simple-asm-expr[opt] attributes[opt]
if (Tok.is(tok::equal) ||
Tok.is(tok::kw_asm) || Tok.is(tok::kw___attribute))
TPR = TPResult::True();
else if (getLangOpts().CPlusPlus11 && Tok.is(tok::l_brace))
TPR = TPResult::True();
else
TPR = TPResult::False();
}
PA.Revert();
assert(TPR == TPResult::True() || TPR == TPResult::False());
return TPR == TPResult::True();
}
/// \brief Determine whether the next set of tokens contains a type-id.
///
/// The context parameter states what context we're parsing right
/// now, which affects how this routine copes with the token
/// following the type-id. If the context is TypeIdInParens, we have
/// already parsed the '(' and we will cease lookahead when we hit
/// the corresponding ')'. If the context is
/// TypeIdAsTemplateArgument, we've already parsed the '<' or ','
/// before this template argument, and will cease lookahead when we
/// hit a '>', '>>' (in C++0x), or ','. Returns true for a type-id
/// and false for an expression. If during the disambiguation
/// process a parsing error is encountered, the function returns
/// true to let the declaration parsing code handle it.
///
/// type-id:
/// type-specifier-seq abstract-declarator[opt]
///
bool Parser::isCXXTypeId(TentativeCXXTypeIdContext Context, bool &isAmbiguous) {
isAmbiguous = false;
// C++ 8.2p2:
// The ambiguity arising from the similarity between a function-style cast and
// a type-id can occur in different contexts. The ambiguity appears as a
// choice between a function-style cast expression and a declaration of a
// type. The resolution is that any construct that could possibly be a type-id
// in its syntactic context shall be considered a type-id.
TPResult TPR = isCXXDeclarationSpecifier();
if (TPR != TPResult::Ambiguous())
return TPR != TPResult::False(); // Returns true for TPResult::True() or
// TPResult::Error().
// FIXME: Add statistics about the number of ambiguous statements encountered
// and how they were resolved (number of declarations+number of expressions).
// Ok, we have a simple-type-specifier/typename-specifier followed by a '('.
// We need tentative parsing...
TentativeParsingAction PA(*this);
// type-specifier-seq
TryConsumeDeclarationSpecifier();
assert(Tok.is(tok::l_paren) && "Expected '('");
// declarator
TPR = TryParseDeclarator(true/*mayBeAbstract*/, false/*mayHaveIdentifier*/);
// In case of an error, let the declaration parsing code handle it.
if (TPR == TPResult::Error())
TPR = TPResult::True();
if (TPR == TPResult::Ambiguous()) {
// We are supposed to be inside parens, so if after the abstract declarator
// we encounter a ')' this is a type-id, otherwise it's an expression.
if (Context == TypeIdInParens && Tok.is(tok::r_paren)) {
TPR = TPResult::True();
isAmbiguous = true;
// We are supposed to be inside a template argument, so if after
// the abstract declarator we encounter a '>', '>>' (in C++0x), or
// ',', this is a type-id. Otherwise, it's an expression.
} else if (Context == TypeIdAsTemplateArgument &&
(Tok.is(tok::greater) || Tok.is(tok::comma) ||
(getLangOpts().CPlusPlus11 && Tok.is(tok::greatergreater)))) {
TPR = TPResult::True();
isAmbiguous = true;
} else
TPR = TPResult::False();
}
PA.Revert();
assert(TPR == TPResult::True() || TPR == TPResult::False());
return TPR == TPResult::True();
}
/// \brief Returns true if this is a C++11 attribute-specifier. Per
/// C++11 [dcl.attr.grammar]p6, two consecutive left square bracket tokens
/// always introduce an attribute. In Objective-C++11, this rule does not
/// apply if either '[' begins a message-send.
///
/// If Disambiguate is true, we try harder to determine whether a '[[' starts
/// an attribute-specifier, and return CAK_InvalidAttributeSpecifier if not.
///
/// If OuterMightBeMessageSend is true, we assume the outer '[' is either an
/// Obj-C message send or the start of an attribute. Otherwise, we assume it
/// is not an Obj-C message send.
///
/// C++11 [dcl.attr.grammar]:
///
/// attribute-specifier:
/// '[' '[' attribute-list ']' ']'
/// alignment-specifier
///
/// attribute-list:
/// attribute[opt]
/// attribute-list ',' attribute[opt]
/// attribute '...'
/// attribute-list ',' attribute '...'
///
/// attribute:
/// attribute-token attribute-argument-clause[opt]
///
/// attribute-token:
/// identifier
/// identifier '::' identifier
///
/// attribute-argument-clause:
/// '(' balanced-token-seq ')'
Parser::CXX11AttributeKind
Parser::isCXX11AttributeSpecifier(bool Disambiguate,
bool OuterMightBeMessageSend) {
if (Tok.is(tok::kw_alignas))
return CAK_AttributeSpecifier;
if (Tok.isNot(tok::l_square) || NextToken().isNot(tok::l_square))
return CAK_NotAttributeSpecifier;
// No tentative parsing if we don't need to look for ']]' or a lambda.
if (!Disambiguate && !getLangOpts().ObjC1)
return CAK_AttributeSpecifier;
TentativeParsingAction PA(*this);
// Opening brackets were checked for above.
ConsumeBracket();
// Outside Obj-C++11, treat anything with a matching ']]' as an attribute.
if (!getLangOpts().ObjC1) {
ConsumeBracket();
bool IsAttribute = SkipUntil(tok::r_square);
IsAttribute &= Tok.is(tok::r_square);
PA.Revert();
return IsAttribute ? CAK_AttributeSpecifier : CAK_InvalidAttributeSpecifier;
}
// In Obj-C++11, we need to distinguish four situations:
// 1a) int x[[attr]]; C++11 attribute.
// 1b) [[attr]]; C++11 statement attribute.
// 2) int x[[obj](){ return 1; }()]; Lambda in array size/index.
// 3a) int x[[obj get]]; Message send in array size/index.
// 3b) [[Class alloc] init]; Message send in message send.
// 4) [[obj]{ return self; }() doStuff]; Lambda in message send.
// (1) is an attribute, (2) is ill-formed, and (3) and (4) are accepted.
// If we have a lambda-introducer, then this is definitely not a message send.
// FIXME: If this disambiguation is too slow, fold the tentative lambda parse
// into the tentative attribute parse below.
LambdaIntroducer Intro;
if (!TryParseLambdaIntroducer(Intro)) {
// A lambda cannot end with ']]', and an attribute must.
bool IsAttribute = Tok.is(tok::r_square);
PA.Revert();
if (IsAttribute)
// Case 1: C++11 attribute.
return CAK_AttributeSpecifier;
if (OuterMightBeMessageSend)
// Case 4: Lambda in message send.
return CAK_NotAttributeSpecifier;
// Case 2: Lambda in array size / index.
return CAK_InvalidAttributeSpecifier;
}
ConsumeBracket();
// If we don't have a lambda-introducer, then we have an attribute or a
// message-send.
bool IsAttribute = true;
while (Tok.isNot(tok::r_square)) {
if (Tok.is(tok::comma)) {
// Case 1: Stray commas can only occur in attributes.
PA.Revert();
return CAK_AttributeSpecifier;
}
// Parse the attribute-token, if present.
// C++11 [dcl.attr.grammar]:
// If a keyword or an alternative token that satisfies the syntactic
// requirements of an identifier is contained in an attribute-token,
// it is considered an identifier.
SourceLocation Loc;
if (!TryParseCXX11AttributeIdentifier(Loc)) {
IsAttribute = false;
break;
}
if (Tok.is(tok::coloncolon)) {
ConsumeToken();
if (!TryParseCXX11AttributeIdentifier(Loc)) {
IsAttribute = false;
break;
}
}
// Parse the attribute-argument-clause, if present.
if (Tok.is(tok::l_paren)) {
ConsumeParen();
if (!SkipUntil(tok::r_paren)) {
IsAttribute = false;
break;
}
}
TryConsumeToken(tok::ellipsis);
if (!TryConsumeToken(tok::comma))
break;
}
// An attribute must end ']]'.
if (IsAttribute) {
if (Tok.is(tok::r_square)) {
ConsumeBracket();
IsAttribute = Tok.is(tok::r_square);
} else {
IsAttribute = false;
}
}
PA.Revert();
if (IsAttribute)
// Case 1: C++11 statement attribute.
return CAK_AttributeSpecifier;
// Case 3: Message send.
return CAK_NotAttributeSpecifier;
}
Parser::TPResult Parser::TryParsePtrOperatorSeq() {
while (true) {
if (Tok.is(tok::coloncolon) || Tok.is(tok::identifier))
if (TryAnnotateCXXScopeToken(true))
return TPResult::Error();
if (Tok.is(tok::star) || Tok.is(tok::amp) || Tok.is(tok::caret) ||
Tok.is(tok::ampamp) ||
(Tok.is(tok::annot_cxxscope) && NextToken().is(tok::star))) {
// ptr-operator
ConsumeToken();
while (Tok.is(tok::kw_const) ||
Tok.is(tok::kw_volatile) ||
Tok.is(tok::kw_restrict))
ConsumeToken();
} else {
return TPResult::True();
}
}
}
/// operator-function-id:
/// 'operator' operator
///
/// operator: one of
/// new delete new[] delete[] + - * / % ^ [...]
///
/// conversion-function-id:
/// 'operator' conversion-type-id
///
/// conversion-type-id:
/// type-specifier-seq conversion-declarator[opt]
///
/// conversion-declarator:
/// ptr-operator conversion-declarator[opt]
///
/// literal-operator-id:
/// 'operator' string-literal identifier
/// 'operator' user-defined-string-literal
Parser::TPResult Parser::TryParseOperatorId() {
assert(Tok.is(tok::kw_operator));
ConsumeToken();
// Maybe this is an operator-function-id.
switch (Tok.getKind()) {
case tok::kw_new: case tok::kw_delete:
ConsumeToken();
if (Tok.is(tok::l_square) && NextToken().is(tok::r_square)) {
ConsumeBracket();
ConsumeBracket();
}
return TPResult::True();
#define OVERLOADED_OPERATOR(Name, Spelling, Token, Unary, Binary, MemOnly) \
case tok::Token:
#define OVERLOADED_OPERATOR_MULTI(Name, Spelling, Unary, Binary, MemOnly)
#include "clang/Basic/OperatorKinds.def"
ConsumeToken();
return TPResult::True();
case tok::l_square:
if (NextToken().is(tok::r_square)) {
ConsumeBracket();
ConsumeBracket();
return TPResult::True();
}
break;
case tok::l_paren:
if (NextToken().is(tok::r_paren)) {
ConsumeParen();
ConsumeParen();
return TPResult::True();
}
break;
default:
break;
}
// Maybe this is a literal-operator-id.
if (getLangOpts().CPlusPlus11 && isTokenStringLiteral()) {
bool FoundUDSuffix = false;
do {
FoundUDSuffix |= Tok.hasUDSuffix();
ConsumeStringToken();
} while (isTokenStringLiteral());
if (!FoundUDSuffix) {
if (Tok.is(tok::identifier))
ConsumeToken();
else
return TPResult::Error();
}
return TPResult::True();
}
// Maybe this is a conversion-function-id.
bool AnyDeclSpecifiers = false;
while (true) {
TPResult TPR = isCXXDeclarationSpecifier();
if (TPR == TPResult::Error())
return TPR;
if (TPR == TPResult::False()) {
if (!AnyDeclSpecifiers)
return TPResult::Error();
break;
}
if (TryConsumeDeclarationSpecifier() == TPResult::Error())
return TPResult::Error();
AnyDeclSpecifiers = true;
}
return TryParsePtrOperatorSeq();
}
/// declarator:
/// direct-declarator
/// ptr-operator declarator
///
/// direct-declarator:
/// declarator-id
/// direct-declarator '(' parameter-declaration-clause ')'
/// cv-qualifier-seq[opt] exception-specification[opt]
/// direct-declarator '[' constant-expression[opt] ']'
/// '(' declarator ')'
/// [GNU] '(' attributes declarator ')'
///
/// abstract-declarator:
/// ptr-operator abstract-declarator[opt]
/// direct-abstract-declarator
/// ...
///
/// direct-abstract-declarator:
/// direct-abstract-declarator[opt]
/// '(' parameter-declaration-clause ')' cv-qualifier-seq[opt]
/// exception-specification[opt]
/// direct-abstract-declarator[opt] '[' constant-expression[opt] ']'
/// '(' abstract-declarator ')'
///
/// ptr-operator:
/// '*' cv-qualifier-seq[opt]
/// '&'
/// [C++0x] '&&' [TODO]
/// '::'[opt] nested-name-specifier '*' cv-qualifier-seq[opt]
///
/// cv-qualifier-seq:
/// cv-qualifier cv-qualifier-seq[opt]
///
/// cv-qualifier:
/// 'const'
/// 'volatile'
///
/// declarator-id:
/// '...'[opt] id-expression
///
/// id-expression:
/// unqualified-id
/// qualified-id [TODO]
///
/// unqualified-id:
/// identifier
/// operator-function-id
/// conversion-function-id
/// literal-operator-id
/// '~' class-name [TODO]
/// '~' decltype-specifier [TODO]
/// template-id [TODO]
///
Parser::TPResult Parser::TryParseDeclarator(bool mayBeAbstract,
bool mayHaveIdentifier) {
// declarator:
// direct-declarator
// ptr-operator declarator
if (TryParsePtrOperatorSeq() == TPResult::Error())
return TPResult::Error();
// direct-declarator:
// direct-abstract-declarator:
if (Tok.is(tok::ellipsis))
ConsumeToken();
if ((Tok.is(tok::identifier) || Tok.is(tok::kw_operator) ||
(Tok.is(tok::annot_cxxscope) && (NextToken().is(tok::identifier) ||
NextToken().is(tok::kw_operator)))) &&
mayHaveIdentifier) {
// declarator-id
if (Tok.is(tok::annot_cxxscope))
ConsumeToken();
else if (Tok.is(tok::identifier))
TentativelyDeclaredIdentifiers.push_back(Tok.getIdentifierInfo());
if (Tok.is(tok::kw_operator)) {
if (TryParseOperatorId() == TPResult::Error())
return TPResult::Error();
} else
ConsumeToken();
} else if (Tok.is(tok::l_paren)) {
ConsumeParen();
if (mayBeAbstract &&
(Tok.is(tok::r_paren) || // 'int()' is a function.
// 'int(...)' is a function.
(Tok.is(tok::ellipsis) && NextToken().is(tok::r_paren)) ||
isDeclarationSpecifier())) { // 'int(int)' is a function.
// '(' parameter-declaration-clause ')' cv-qualifier-seq[opt]
// exception-specification[opt]
TPResult TPR = TryParseFunctionDeclarator();
if (TPR != TPResult::Ambiguous())
return TPR;
} else {
// '(' declarator ')'
// '(' attributes declarator ')'
// '(' abstract-declarator ')'
if (Tok.is(tok::kw___attribute) ||
Tok.is(tok::kw___declspec) ||
Tok.is(tok::kw___cdecl) ||
Tok.is(tok::kw___stdcall) ||
Tok.is(tok::kw___fastcall) ||
Tok.is(tok::kw___thiscall) ||
Tok.is(tok::kw___unaligned))
return TPResult::True(); // attributes indicate declaration
TPResult TPR = TryParseDeclarator(mayBeAbstract, mayHaveIdentifier);
if (TPR != TPResult::Ambiguous())
return TPR;
if (Tok.isNot(tok::r_paren))
return TPResult::False();
ConsumeParen();
}
} else if (!mayBeAbstract) {
return TPResult::False();
}
while (1) {
TPResult TPR(TPResult::Ambiguous());
// abstract-declarator: ...
if (Tok.is(tok::ellipsis))
ConsumeToken();
if (Tok.is(tok::l_paren)) {
// Check whether we have a function declarator or a possible ctor-style
// initializer that follows the declarator. Note that ctor-style
// initializers are not possible in contexts where abstract declarators
// are allowed.
if (!mayBeAbstract && !isCXXFunctionDeclarator())
break;
// direct-declarator '(' parameter-declaration-clause ')'
// cv-qualifier-seq[opt] exception-specification[opt]
ConsumeParen();
TPR = TryParseFunctionDeclarator();
} else if (Tok.is(tok::l_square)) {
// direct-declarator '[' constant-expression[opt] ']'
// direct-abstract-declarator[opt] '[' constant-expression[opt] ']'
TPR = TryParseBracketDeclarator();
} else {
break;
}
if (TPR != TPResult::Ambiguous())
return TPR;
}
return TPResult::Ambiguous();
}
Parser::TPResult
Parser::isExpressionOrTypeSpecifierSimple(tok::TokenKind Kind) {
switch (Kind) {
// Obviously starts an expression.
case tok::numeric_constant:
case tok::char_constant:
case tok::wide_char_constant:
case tok::utf16_char_constant:
case tok::utf32_char_constant:
case tok::string_literal:
case tok::wide_string_literal:
case tok::utf8_string_literal:
case tok::utf16_string_literal:
case tok::utf32_string_literal:
case tok::l_square:
case tok::l_paren:
case tok::amp:
case tok::ampamp:
case tok::star:
case tok::plus:
case tok::plusplus:
case tok::minus:
case tok::minusminus:
case tok::tilde:
case tok::exclaim:
case tok::kw_sizeof:
case tok::kw___func__:
case tok::kw_const_cast:
case tok::kw_delete:
case tok::kw_dynamic_cast:
case tok::kw_false:
case tok::kw_new:
case tok::kw_operator:
case tok::kw_reinterpret_cast:
case tok::kw_static_cast:
case tok::kw_this:
case tok::kw_throw:
case tok::kw_true:
case tok::kw_typeid:
case tok::kw_alignof:
case tok::kw_noexcept:
case tok::kw_nullptr:
case tok::kw__Alignof:
case tok::kw___null:
case tok::kw___alignof:
case tok::kw___builtin_choose_expr:
case tok::kw___builtin_offsetof:
case tok::kw___builtin_va_arg:
case tok::kw___imag:
case tok::kw___real:
case tok::kw___FUNCTION__:
case tok::kw___FUNCDNAME__:
case tok::kw___FUNCSIG__:
case tok::kw_L__FUNCTION__:
case tok::kw___PRETTY_FUNCTION__:
case tok::kw___uuidof:
#define TYPE_TRAIT(N,Spelling,K) \
case tok::kw_##Spelling:
#include "clang/Basic/TokenKinds.def"
return TPResult::True();
// Obviously starts a type-specifier-seq:
case tok::kw_char:
case tok::kw_const:
case tok::kw_double:
case tok::kw_enum:
case tok::kw_half:
case tok::kw_float:
case tok::kw_int:
case tok::kw_long:
case tok::kw___int64:
case tok::kw___int128:
case tok::kw_restrict:
case tok::kw_short:
case tok::kw_signed:
case tok::kw_struct:
case tok::kw_union:
case tok::kw_unsigned:
case tok::kw_void:
case tok::kw_volatile:
case tok::kw__Bool:
case tok::kw__Complex:
case tok::kw_class:
case tok::kw_typename:
case tok::kw_wchar_t:
case tok::kw_char16_t:
case tok::kw_char32_t:
case tok::kw__Decimal32:
case tok::kw__Decimal64:
case tok::kw__Decimal128:
case tok::kw___interface:
case tok::kw___thread:
case tok::kw_thread_local:
case tok::kw__Thread_local:
case tok::kw_typeof:
case tok::kw___underlying_type:
case tok::kw___cdecl:
case tok::kw___stdcall:
case tok::kw___fastcall:
case tok::kw___thiscall:
case tok::kw___unaligned:
case tok::kw___vector:
case tok::kw___pixel:
case tok::kw__Atomic:
case tok::kw___unknown_anytype:
return TPResult::False();
default:
break;
}
return TPResult::Ambiguous();
}
bool Parser::isTentativelyDeclared(IdentifierInfo *II) {
return std::find(TentativelyDeclaredIdentifiers.begin(),
TentativelyDeclaredIdentifiers.end(), II)
!= TentativelyDeclaredIdentifiers.end();
}
/// isCXXDeclarationSpecifier - Returns TPResult::True() if it is a declaration
/// specifier, TPResult::False() if it is not, TPResult::Ambiguous() if it could
/// be either a decl-specifier or a function-style cast, and TPResult::Error()
/// if a parsing error was found and reported.
///
/// If HasMissingTypename is provided, a name with a dependent scope specifier
/// will be treated as ambiguous if the 'typename' keyword is missing. If this
/// happens, *HasMissingTypename will be set to 'true'. This will also be used
/// as an indicator that undeclared identifiers (which will trigger a later
/// parse error) should be treated as types. Returns TPResult::Ambiguous() in
/// such cases.
///
/// decl-specifier:
/// storage-class-specifier
/// type-specifier
/// function-specifier
/// 'friend'
/// 'typedef'
/// [C++11] 'constexpr'
/// [GNU] attributes declaration-specifiers[opt]
///
/// storage-class-specifier:
/// 'register'
/// 'static'
/// 'extern'
/// 'mutable'
/// 'auto'
/// [GNU] '__thread'
/// [C++11] 'thread_local'
/// [C11] '_Thread_local'
///
/// function-specifier:
/// 'inline'
/// 'virtual'
/// 'explicit'
///
/// typedef-name:
/// identifier
///
/// type-specifier:
/// simple-type-specifier
/// class-specifier
/// enum-specifier
/// elaborated-type-specifier
/// typename-specifier
/// cv-qualifier
///
/// 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
/// [GNU] '_Complex'
/// [C++11] 'auto'
/// [C++11] 'decltype' ( expression )
/// [C++1y] 'decltype' ( 'auto' )
///
/// type-name:
/// class-name
/// enum-name
/// typedef-name
///
/// elaborated-type-specifier:
/// class-key '::'[opt] nested-name-specifier[opt] identifier
/// class-key '::'[opt] nested-name-specifier[opt] 'template'[opt]
/// simple-template-id
/// 'enum' '::'[opt] nested-name-specifier[opt] identifier
///
/// enum-name:
/// identifier
///
/// enum-specifier:
/// 'enum' identifier[opt] '{' enumerator-list[opt] '}'
/// 'enum' identifier[opt] '{' enumerator-list ',' '}'
///
/// class-specifier:
/// class-head '{' member-specification[opt] '}'
///
/// class-head:
/// class-key identifier[opt] base-clause[opt]
/// class-key nested-name-specifier identifier base-clause[opt]
/// class-key nested-name-specifier[opt] simple-template-id
/// base-clause[opt]
///
/// class-key:
/// 'class'
/// 'struct'
/// 'union'
///
/// cv-qualifier:
/// 'const'
/// 'volatile'
/// [GNU] restrict
///
Parser::TPResult
Parser::isCXXDeclarationSpecifier(Parser::TPResult BracedCastResult,
bool *HasMissingTypename) {
switch (Tok.getKind()) {
case tok::identifier: {
// Check for need to substitute AltiVec __vector keyword
// for "vector" identifier.
if (TryAltiVecVectorToken())
return TPResult::True();
const Token &Next = NextToken();
// In 'foo bar', 'foo' is always a type name outside of Objective-C.
if (!getLangOpts().ObjC1 && Next.is(tok::identifier))
return TPResult::True();
if (Next.isNot(tok::coloncolon) && Next.isNot(tok::less)) {
// Determine whether this is a valid expression. If not, we will hit
// a parse error one way or another. In that case, tell the caller that
// this is ambiguous. Typo-correct to type and expression keywords and
// to types and identifiers, in order to try to recover from errors.
CorrectionCandidateCallback TypoCorrection;
TypoCorrection.WantRemainingKeywords = false;
TypoCorrection.WantTypeSpecifiers = Next.isNot(tok::arrow);
switch (TryAnnotateName(false /* no nested name specifier */,
&TypoCorrection)) {
case ANK_Error:
return TPResult::Error();
case ANK_TentativeDecl:
return TPResult::False();
case ANK_TemplateName:
// A bare type template-name which can't be a template template
// argument is an error, and was probably intended to be a type.
return GreaterThanIsOperator ? TPResult::True() : TPResult::False();
case ANK_Unresolved:
return HasMissingTypename ? TPResult::Ambiguous() : TPResult::False();
case ANK_Success:
break;
}
assert(Tok.isNot(tok::identifier) &&
"TryAnnotateName succeeded without producing an annotation");
} else {
// This might possibly be a type with a dependent scope specifier and
// a missing 'typename' keyword. Don't use TryAnnotateName in this case,
// since it will annotate as a primary expression, and we want to use the
// "missing 'typename'" logic.
if (TryAnnotateTypeOrScopeToken())
return TPResult::Error();
// If annotation failed, assume it's a non-type.
// FIXME: If this happens due to an undeclared identifier, treat it as
// ambiguous.
if (Tok.is(tok::identifier))
return TPResult::False();
}
// We annotated this token as something. Recurse to handle whatever we got.
return isCXXDeclarationSpecifier(BracedCastResult, HasMissingTypename);
}
case tok::kw_typename: // typename T::type
// Annotate typenames and C++ scope specifiers. If we get one, just
// recurse to handle whatever we get.
if (TryAnnotateTypeOrScopeToken())
return TPResult::Error();
return isCXXDeclarationSpecifier(BracedCastResult, HasMissingTypename);
case tok::coloncolon: { // ::foo::bar
const Token &Next = NextToken();
if (Next.is(tok::kw_new) || // ::new
Next.is(tok::kw_delete)) // ::delete
return TPResult::False();
}
// Fall through.
case tok::kw_decltype:
// Annotate typenames and C++ scope specifiers. If we get one, just
// recurse to handle whatever we get.
if (TryAnnotateTypeOrScopeToken())
return TPResult::Error();
return isCXXDeclarationSpecifier(BracedCastResult, HasMissingTypename);
// decl-specifier:
// storage-class-specifier
// type-specifier
// function-specifier
// 'friend'
// 'typedef'
// 'constexpr'
case tok::kw_friend:
case tok::kw_typedef:
case tok::kw_constexpr:
// storage-class-specifier
case tok::kw_register:
case tok::kw_static:
case tok::kw_extern:
case tok::kw_mutable:
case tok::kw_auto:
case tok::kw___thread:
case tok::kw_thread_local:
case tok::kw__Thread_local:
// function-specifier
case tok::kw_inline:
case tok::kw_virtual:
case tok::kw_explicit:
// Modules
case tok::kw___module_private__:
// Debugger support
case tok::kw___unknown_anytype:
// type-specifier:
// simple-type-specifier
// class-specifier
// enum-specifier
// elaborated-type-specifier
// typename-specifier
// cv-qualifier
// class-specifier
// elaborated-type-specifier
case tok::kw_class:
case tok::kw_struct:
case tok::kw_union:
case tok::kw___interface:
// enum-specifier
case tok::kw_enum:
// cv-qualifier
case tok::kw_const:
case tok::kw_volatile:
// GNU
case tok::kw_restrict:
case tok::kw__Complex:
case tok::kw___attribute:
return TPResult::True();
// Microsoft
case tok::kw___declspec:
case tok::kw___cdecl:
case tok::kw___stdcall:
case tok::kw___fastcall:
case tok::kw___thiscall:
case tok::kw___w64:
case tok::kw___sptr:
case tok::kw___uptr:
case tok::kw___ptr64:
case tok::kw___ptr32:
case tok::kw___forceinline:
case tok::kw___unaligned:
return TPResult::True();
// Borland
case tok::kw___pascal:
return TPResult::True();
// AltiVec
case tok::kw___vector:
return TPResult::True();
case tok::annot_template_id: {
TemplateIdAnnotation *TemplateId = takeTemplateIdAnnotation(Tok);
if (TemplateId->Kind != TNK_Type_template)
return TPResult::False();
CXXScopeSpec SS;
AnnotateTemplateIdTokenAsType();
assert(Tok.is(tok::annot_typename));
goto case_typename;
}
case tok::annot_cxxscope: // foo::bar or ::foo::bar, but already parsed
// We've already annotated a scope; try to annotate a type.
if (TryAnnotateTypeOrScopeToken())
return TPResult::Error();
if (!Tok.is(tok::annot_typename)) {
// If the next token is an identifier or a type qualifier, then this
// can't possibly be a valid expression either.
if (Tok.is(tok::annot_cxxscope) && NextToken().is(tok::identifier)) {
CXXScopeSpec SS;
Actions.RestoreNestedNameSpecifierAnnotation(Tok.getAnnotationValue(),
Tok.getAnnotationRange(),
SS);
if (SS.getScopeRep() && SS.getScopeRep()->isDependent()) {
TentativeParsingAction PA(*this);
ConsumeToken();
ConsumeToken();
bool isIdentifier = Tok.is(tok::identifier);
TPResult TPR = TPResult::False();
if (!isIdentifier)
TPR = isCXXDeclarationSpecifier(BracedCastResult,
HasMissingTypename);
PA.Revert();
if (isIdentifier ||
TPR == TPResult::True() || TPR == TPResult::Error())
return TPResult::Error();
if (HasMissingTypename) {
// We can't tell whether this is a missing 'typename' or a valid
// expression.
*HasMissingTypename = true;
return TPResult::Ambiguous();
}
} else {
// Try to resolve the name. If it doesn't exist, assume it was
// intended to name a type and keep disambiguating.
switch (TryAnnotateName(false /* SS is not dependent */)) {
case ANK_Error:
return TPResult::Error();
case ANK_TentativeDecl:
return TPResult::False();
case ANK_TemplateName:
// A bare type template-name which can't be a template template
// argument is an error, and was probably intended to be a type.
return GreaterThanIsOperator ? TPResult::True() : TPResult::False();
case ANK_Unresolved:
return HasMissingTypename ? TPResult::Ambiguous()
: TPResult::False();
case ANK_Success:
// Annotated it, check again.
assert(Tok.isNot(tok::annot_cxxscope) ||
NextToken().isNot(tok::identifier));
return isCXXDeclarationSpecifier(BracedCastResult,
HasMissingTypename);
}
}
}
return TPResult::False();
}
// If that succeeded, fallthrough into the generic simple-type-id case.
// The ambiguity resides in a simple-type-specifier/typename-specifier
// followed by a '('. The '(' could either be the start of:
//
// direct-declarator:
// '(' declarator ')'
//
// direct-abstract-declarator:
// '(' parameter-declaration-clause ')' cv-qualifier-seq[opt]
// exception-specification[opt]
// '(' abstract-declarator ')'
//
// or part of a function-style cast expression:
//
// simple-type-specifier '(' expression-list[opt] ')'
//
// simple-type-specifier:
case tok::annot_typename:
case_typename:
// In Objective-C, we might have a protocol-qualified type.
if (getLangOpts().ObjC1 && NextToken().is(tok::less)) {
// Tentatively parse the
TentativeParsingAction PA(*this);
ConsumeToken(); // The type token
TPResult TPR = TryParseProtocolQualifiers();
bool isFollowedByParen = Tok.is(tok::l_paren);
bool isFollowedByBrace = Tok.is(tok::l_brace);
PA.Revert();
if (TPR == TPResult::Error())
return TPResult::Error();
if (isFollowedByParen)
return TPResult::Ambiguous();
if (getLangOpts().CPlusPlus11 && isFollowedByBrace)
return BracedCastResult;
return TPResult::True();
}
case tok::kw_char:
case tok::kw_wchar_t:
case tok::kw_char16_t:
case tok::kw_char32_t:
case tok::kw_bool:
case tok::kw_short:
case tok::kw_int:
case tok::kw_long:
case tok::kw___int64:
case tok::kw___int128:
case tok::kw_signed:
case tok::kw_unsigned:
case tok::kw_half:
case tok::kw_float:
case tok::kw_double:
case tok::kw_void:
case tok::annot_decltype:
if (NextToken().is(tok::l_paren))
return TPResult::Ambiguous();
// This is a function-style cast in all cases we disambiguate other than
// one:
// struct S {
// enum E : int { a = 4 }; // enum
// enum E : int { 4 }; // bit-field
// };
if (getLangOpts().CPlusPlus11 && NextToken().is(tok::l_brace))
return BracedCastResult;
if (isStartOfObjCClassMessageMissingOpenBracket())
return TPResult::False();
return TPResult::True();
// GNU typeof support.
case tok::kw_typeof: {
if (NextToken().isNot(tok::l_paren))
return TPResult::True();
TentativeParsingAction PA(*this);
TPResult TPR = TryParseTypeofSpecifier();
bool isFollowedByParen = Tok.is(tok::l_paren);
bool isFollowedByBrace = Tok.is(tok::l_brace);
PA.Revert();
if (TPR == TPResult::Error())
return TPResult::Error();
if (isFollowedByParen)
return TPResult::Ambiguous();
if (getLangOpts().CPlusPlus11 && isFollowedByBrace)
return BracedCastResult;
return TPResult::True();
}
// C++0x type traits support
case tok::kw___underlying_type:
return TPResult::True();
// C11 _Atomic
case tok::kw__Atomic:
return TPResult::True();
default:
return TPResult::False();
}
}
bool Parser::isCXXDeclarationSpecifierAType() {
switch (Tok.getKind()) {
// typename-specifier
case tok::annot_decltype:
case tok::annot_template_id:
case tok::annot_typename:
case tok::kw_typeof:
case tok::kw___underlying_type:
return true;
// elaborated-type-specifier
case tok::kw_class:
case tok::kw_struct:
case tok::kw_union:
case tok::kw___interface:
case tok::kw_enum:
return true;
// simple-type-specifier
case tok::kw_char:
case tok::kw_wchar_t:
case tok::kw_char16_t:
case tok::kw_char32_t:
case tok::kw_bool:
case tok::kw_short:
case tok::kw_int:
case tok::kw_long:
case tok::kw___int64:
case tok::kw___int128:
case tok::kw_signed:
case tok::kw_unsigned:
case tok::kw_half:
case tok::kw_float:
case tok::kw_double:
case tok::kw_void:
case tok::kw___unknown_anytype:
return true;
case tok::kw_auto:
return getLangOpts().CPlusPlus11;
case tok::kw__Atomic:
// "_Atomic foo"
return NextToken().is(tok::l_paren);
default:
return false;
}
}
/// [GNU] typeof-specifier:
/// 'typeof' '(' expressions ')'
/// 'typeof' '(' type-name ')'
///
Parser::TPResult Parser::TryParseTypeofSpecifier() {
assert(Tok.is(tok::kw_typeof) && "Expected 'typeof'!");
ConsumeToken();
assert(Tok.is(tok::l_paren) && "Expected '('");
// Parse through the parens after 'typeof'.
ConsumeParen();
if (!SkipUntil(tok::r_paren, StopAtSemi))
return TPResult::Error();
return TPResult::Ambiguous();
}
/// [ObjC] protocol-qualifiers:
//// '<' identifier-list '>'
Parser::TPResult Parser::TryParseProtocolQualifiers() {
assert(Tok.is(tok::less) && "Expected '<' for qualifier list");
ConsumeToken();
do {
if (Tok.isNot(tok::identifier))
return TPResult::Error();
ConsumeToken();
if (Tok.is(tok::comma)) {
ConsumeToken();
continue;
}
if (Tok.is(tok::greater)) {
ConsumeToken();
return TPResult::Ambiguous();
}
} while (false);
return TPResult::Error();
}
/// isCXXFunctionDeclarator - Disambiguates between a function declarator or
/// a constructor-style initializer, when parsing declaration statements.
/// Returns true for function declarator and false for constructor-style
/// initializer.
/// If during the disambiguation process a parsing error is encountered,
/// the function returns true to let the declaration parsing code handle it.
///
/// '(' parameter-declaration-clause ')' cv-qualifier-seq[opt]
/// exception-specification[opt]
///
bool Parser::isCXXFunctionDeclarator(bool *IsAmbiguous) {
// C++ 8.2p1:
// The ambiguity arising from the similarity between a function-style cast and
// a declaration mentioned in 6.8 can also occur in the context of a
// declaration. In that context, the choice is between a function declaration
// with a redundant set of parentheses around a parameter name and an object
// declaration with a function-style cast as the initializer. Just as for the
// ambiguities mentioned in 6.8, the resolution is to consider any construct
// that could possibly be a declaration a declaration.
TentativeParsingAction PA(*this);
ConsumeParen();
bool InvalidAsDeclaration = false;
TPResult TPR = TryParseParameterDeclarationClause(&InvalidAsDeclaration);
if (TPR == TPResult::Ambiguous()) {
if (Tok.isNot(tok::r_paren))
TPR = TPResult::False();
else {
const Token &Next = NextToken();
if (Next.is(tok::amp) || Next.is(tok::ampamp) ||
Next.is(tok::kw_const) || Next.is(tok::kw_volatile) ||
Next.is(tok::kw_throw) || Next.is(tok::kw_noexcept) ||
Next.is(tok::l_square) || isCXX11VirtSpecifier(Next) ||
Next.is(tok::l_brace) || Next.is(tok::kw_try) ||
Next.is(tok::equal) || Next.is(tok::arrow))
// The next token cannot appear after a constructor-style initializer,
// and can appear next in a function definition. This must be a function
// declarator.
TPR = TPResult::True();
else if (InvalidAsDeclaration)
// Use the absence of 'typename' as a tie-breaker.
TPR = TPResult::False();
}
}
PA.Revert();
if (IsAmbiguous && TPR == TPResult::Ambiguous())
*IsAmbiguous = true;
// In case of an error, let the declaration parsing code handle it.
return TPR != TPResult::False();
}
/// parameter-declaration-clause:
/// parameter-declaration-list[opt] '...'[opt]
/// parameter-declaration-list ',' '...'
///
/// parameter-declaration-list:
/// parameter-declaration
/// parameter-declaration-list ',' parameter-declaration
///
/// parameter-declaration:
/// attribute-specifier-seq[opt] decl-specifier-seq declarator attributes[opt]
/// attribute-specifier-seq[opt] decl-specifier-seq declarator attributes[opt]
/// '=' assignment-expression
/// attribute-specifier-seq[opt] decl-specifier-seq abstract-declarator[opt]
/// attributes[opt]
/// attribute-specifier-seq[opt] decl-specifier-seq abstract-declarator[opt]
/// attributes[opt] '=' assignment-expression
///
Parser::TPResult
Parser::TryParseParameterDeclarationClause(bool *InvalidAsDeclaration,
bool VersusTemplateArgument) {
if (Tok.is(tok::r_paren))
return TPResult::Ambiguous();
// parameter-declaration-list[opt] '...'[opt]
// parameter-declaration-list ',' '...'
//
// parameter-declaration-list:
// parameter-declaration
// parameter-declaration-list ',' parameter-declaration
//
while (1) {
// '...'[opt]
if (Tok.is(tok::ellipsis)) {
ConsumeToken();
if (Tok.is(tok::r_paren))
return TPResult::True(); // '...)' is a sign of a function declarator.
else
return TPResult::False();
}
// An attribute-specifier-seq here is a sign of a function declarator.
if (isCXX11AttributeSpecifier(/*Disambiguate*/false,
/*OuterMightBeMessageSend*/true))
return TPResult::True();
ParsedAttributes attrs(AttrFactory);
MaybeParseMicrosoftAttributes(attrs);
// decl-specifier-seq
// A parameter-declaration's initializer must be preceded by an '=', so
// decl-specifier-seq '{' is not a parameter in C++11.
TPResult TPR = isCXXDeclarationSpecifier(TPResult::False(),
InvalidAsDeclaration);
if (VersusTemplateArgument && TPR == TPResult::True()) {
// Consume the decl-specifier-seq. We have to look past it, since a
// type-id might appear here in a template argument.
bool SeenType = false;
do {
SeenType |= isCXXDeclarationSpecifierAType();
if (TryConsumeDeclarationSpecifier() == TPResult::Error())
return TPResult::Error();
// If we see a parameter name, this can't be a template argument.
if (SeenType && Tok.is(tok::identifier))
return TPResult::True();
TPR = isCXXDeclarationSpecifier(TPResult::False(),
InvalidAsDeclaration);
if (TPR == TPResult::Error())
return TPR;
} while (TPR != TPResult::False());
} else if (TPR == TPResult::Ambiguous()) {
// Disambiguate what follows the decl-specifier.
if (TryConsumeDeclarationSpecifier() == TPResult::Error())
return TPResult::Error();
} else
return TPR;
// declarator
// abstract-declarator[opt]
TPR = TryParseDeclarator(true/*mayBeAbstract*/);
if (TPR != TPResult::Ambiguous())
return TPR;
// [GNU] attributes[opt]
if (Tok.is(tok::kw___attribute))
return TPResult::True();
// If we're disambiguating a template argument in a default argument in
// a class definition versus a parameter declaration, an '=' here
// disambiguates the parse one way or the other.
// If this is a parameter, it must have a default argument because
// (a) the previous parameter did, and
// (b) this must be the first declaration of the function, so we can't
// inherit any default arguments from elsewhere.
// If we see an ')', then we've reached the end of a
// parameter-declaration-clause, and the last param is missing its default
// argument.
if (VersusTemplateArgument)
return (Tok.is(tok::equal) || Tok.is(tok::r_paren)) ? TPResult::True()
: TPResult::False();
if (Tok.is(tok::equal)) {
// '=' assignment-expression
// Parse through assignment-expression.
// FIXME: assignment-expression may contain an unparenthesized comma.
if (!SkipUntil(tok::comma, tok::r_paren, StopAtSemi | StopBeforeMatch))
return TPResult::Error();
}
if (Tok.is(tok::ellipsis)) {
ConsumeToken();
if (Tok.is(tok::r_paren))
return TPResult::True(); // '...)' is a sign of a function declarator.
else
return TPResult::False();
}
if (!TryConsumeToken(tok::comma))
break;
}
return TPResult::Ambiguous();
}
/// TryParseFunctionDeclarator - We parsed a '(' and we want to try to continue
/// parsing as a function declarator.
/// If TryParseFunctionDeclarator fully parsed the function declarator, it will
/// return TPResult::Ambiguous(), otherwise it will return either False() or
/// Error().
///
/// '(' parameter-declaration-clause ')' cv-qualifier-seq[opt]
/// exception-specification[opt]
///
/// exception-specification:
/// 'throw' '(' type-id-list[opt] ')'
///
Parser::TPResult Parser::TryParseFunctionDeclarator() {
// The '(' is already parsed.
TPResult TPR = TryParseParameterDeclarationClause();
if (TPR == TPResult::Ambiguous() && Tok.isNot(tok::r_paren))
TPR = TPResult::False();
if (TPR == TPResult::False() || TPR == TPResult::Error())
return TPR;
// Parse through the parens.
if (!SkipUntil(tok::r_paren, StopAtSemi))
return TPResult::Error();
// cv-qualifier-seq
while (Tok.is(tok::kw_const) ||
Tok.is(tok::kw_volatile) ||
Tok.is(tok::kw_restrict) )
ConsumeToken();
// ref-qualifier[opt]
if (Tok.is(tok::amp) || Tok.is(tok::ampamp))
ConsumeToken();
// exception-specification
if (Tok.is(tok::kw_throw)) {
ConsumeToken();
if (Tok.isNot(tok::l_paren))
return TPResult::Error();
// Parse through the parens after 'throw'.
ConsumeParen();
if (!SkipUntil(tok::r_paren, StopAtSemi))
return TPResult::Error();
}
if (Tok.is(tok::kw_noexcept)) {
ConsumeToken();
// Possibly an expression as well.
if (Tok.is(tok::l_paren)) {
// Find the matching rparen.
ConsumeParen();
if (!SkipUntil(tok::r_paren, StopAtSemi))
return TPResult::Error();
}
}
return TPResult::Ambiguous();
}
/// '[' constant-expression[opt] ']'
///
Parser::TPResult Parser::TryParseBracketDeclarator() {
ConsumeBracket();
if (!SkipUntil(tok::r_square, StopAtSemi))
return TPResult::Error();
return TPResult::Ambiguous();
}