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llvm-project/clang/lib/Parse/Parser.cpp

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//===--- Parser.cpp - C Language Family Parser ----------------------------===//
//
// 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 Parser interfaces.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "clang/Parse/ParseDiagnostic.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Parse/Scope.h"
#include "llvm/Support/raw_ostream.h"
#include "ExtensionRAIIObject.h"
#include "ParsePragma.h"
using namespace clang;
/// \brief A comment handler that passes comments found by the preprocessor
/// to the parser action.
class ActionCommentHandler : public CommentHandler {
Action &Actions;
public:
explicit ActionCommentHandler(Action &Actions) : Actions(Actions) { }
virtual void HandleComment(Preprocessor &PP, SourceRange Comment) {
Actions.ActOnComment(Comment);
}
};
Parser::Parser(Preprocessor &pp, Action &actions)
: CrashInfo(*this), PP(pp), Actions(actions), Diags(PP.getDiagnostics()),
GreaterThanIsOperator(true), TemplateParameterDepth(0) {
Tok.setKind(tok::eof);
CurScope = 0;
NumCachedScopes = 0;
ParenCount = BracketCount = BraceCount = 0;
ObjCImpDecl = DeclPtrTy();
// Add #pragma handlers. These are removed and destroyed in the
// destructor.
PackHandler.reset(new
PragmaPackHandler(&PP.getIdentifierTable().get("pack"), actions));
PP.AddPragmaHandler(0, PackHandler.get());
UnusedHandler.reset(new
PragmaUnusedHandler(&PP.getIdentifierTable().get("unused"), actions,
*this));
PP.AddPragmaHandler(0, UnusedHandler.get());
WeakHandler.reset(new
PragmaWeakHandler(&PP.getIdentifierTable().get("weak"), actions));
PP.AddPragmaHandler(0, WeakHandler.get());
CommentHandler.reset(new ActionCommentHandler(actions));
PP.AddCommentHandler(CommentHandler.get());
}
/// If a crash happens while the parser is active, print out a line indicating
/// what the current token is.
void PrettyStackTraceParserEntry::print(llvm::raw_ostream &OS) const {
const Token &Tok = P.getCurToken();
if (Tok.is(tok::eof)) {
OS << "<eof> parser at end of file\n";
return;
}
if (Tok.getLocation().isInvalid()) {
OS << "<unknown> parser at unknown location\n";
return;
}
const Preprocessor &PP = P.getPreprocessor();
Tok.getLocation().print(OS, PP.getSourceManager());
OS << ": current parser token '" << PP.getSpelling(Tok) << "'\n";
}
DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
return Diags.Report(FullSourceLoc(Loc, PP.getSourceManager()), DiagID);
}
DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {
return Diag(Tok.getLocation(), DiagID);
}
/// \brief Emits a diagnostic suggesting parentheses surrounding a
/// given range.
///
/// \param Loc The location where we'll emit the diagnostic.
/// \param Loc The kind of diagnostic to emit.
/// \param ParenRange Source range enclosing code that should be parenthesized.
void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK,
SourceRange ParenRange) {
SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd());
if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
// We can't display the parentheses, so just dig the
// warning/error and return.
Diag(Loc, DK);
return;
}
Diag(Loc, DK)
<< CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(")
<< CodeModificationHint::CreateInsertion(EndLoc, ")");
}
/// MatchRHSPunctuation - For punctuation with a LHS and RHS (e.g. '['/']'),
/// this helper function matches and consumes the specified RHS token if
/// present. If not present, it emits the specified diagnostic indicating
/// that the parser failed to match the RHS of the token at LHSLoc. LHSName
/// should be the name of the unmatched LHS token.
SourceLocation Parser::MatchRHSPunctuation(tok::TokenKind RHSTok,
SourceLocation LHSLoc) {
if (Tok.is(RHSTok))
return ConsumeAnyToken();
SourceLocation R = Tok.getLocation();
const char *LHSName = "unknown";
diag::kind DID = diag::err_parse_error;
switch (RHSTok) {
default: break;
case tok::r_paren : LHSName = "("; DID = diag::err_expected_rparen; break;
case tok::r_brace : LHSName = "{"; DID = diag::err_expected_rbrace; break;
case tok::r_square: LHSName = "["; DID = diag::err_expected_rsquare; break;
case tok::greater: LHSName = "<"; DID = diag::err_expected_greater; break;
}
Diag(Tok, DID);
Diag(LHSLoc, diag::note_matching) << LHSName;
SkipUntil(RHSTok);
return R;
}
/// ExpectAndConsume - The parser expects that 'ExpectedTok' is next in the
/// input. If so, it is consumed and false is returned.
///
/// If the input is malformed, this emits the specified diagnostic. Next, if
/// SkipToTok is specified, it calls SkipUntil(SkipToTok). Finally, true is
/// returned.
bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
const char *Msg, tok::TokenKind SkipToTok) {
if (Tok.is(ExpectedTok)) {
ConsumeAnyToken();
return false;
}
const char *Spelling = 0;
SourceLocation EndLoc = PP.getLocForEndOfToken(PrevTokLocation);
if (EndLoc.isValid() &&
(Spelling = tok::getTokenSimpleSpelling(ExpectedTok))) {
// Show what code to insert to fix this problem.
Diag(EndLoc, DiagID)
<< Msg
<< CodeModificationHint::CreateInsertion(EndLoc, Spelling);
} else
Diag(Tok, DiagID) << Msg;
if (SkipToTok != tok::unknown)
SkipUntil(SkipToTok);
return true;
}
//===----------------------------------------------------------------------===//
// Error recovery.
//===----------------------------------------------------------------------===//
/// SkipUntil - Read tokens until we get to the specified token, then consume
/// it (unless DontConsume is true). Because we cannot guarantee that the
/// token will ever occur, this skips to the next token, or to some likely
/// good stopping point. If StopAtSemi is true, skipping will stop at a ';'
/// character.
///
/// If SkipUntil finds the specified token, it returns true, otherwise it
/// returns false.
bool Parser::SkipUntil(const tok::TokenKind *Toks, unsigned NumToks,
bool StopAtSemi, bool DontConsume) {
// We always want this function to skip at least one token if the first token
// isn't T and if not at EOF.
bool isFirstTokenSkipped = true;
while (1) {
// If we found one of the tokens, stop and return true.
for (unsigned i = 0; i != NumToks; ++i) {
if (Tok.is(Toks[i])) {
if (DontConsume) {
// Noop, don't consume the token.
} else {
ConsumeAnyToken();
}
return true;
}
}
switch (Tok.getKind()) {
case tok::eof:
// Ran out of tokens.
return false;
case tok::l_paren:
// Recursively skip properly-nested parens.
ConsumeParen();
SkipUntil(tok::r_paren, false);
break;
case tok::l_square:
// Recursively skip properly-nested square brackets.
ConsumeBracket();
SkipUntil(tok::r_square, false);
break;
case tok::l_brace:
// Recursively skip properly-nested braces.
ConsumeBrace();
SkipUntil(tok::r_brace, false);
break;
// Okay, we found a ']' or '}' or ')', which we think should be balanced.
// Since the user wasn't looking for this token (if they were, it would
// already be handled), this isn't balanced. If there is a LHS token at a
// higher level, we will assume that this matches the unbalanced token
// and return it. Otherwise, this is a spurious RHS token, which we skip.
case tok::r_paren:
if (ParenCount && !isFirstTokenSkipped)
return false; // Matches something.
ConsumeParen();
break;
case tok::r_square:
if (BracketCount && !isFirstTokenSkipped)
return false; // Matches something.
ConsumeBracket();
break;
case tok::r_brace:
if (BraceCount && !isFirstTokenSkipped)
return false; // Matches something.
ConsumeBrace();
break;
case tok::string_literal:
case tok::wide_string_literal:
ConsumeStringToken();
break;
case tok::semi:
if (StopAtSemi)
return false;
// FALL THROUGH.
default:
// Skip this token.
ConsumeToken();
break;
}
isFirstTokenSkipped = false;
}
}
//===----------------------------------------------------------------------===//
// Scope manipulation
//===----------------------------------------------------------------------===//
/// EnterScope - Start a new scope.
void Parser::EnterScope(unsigned ScopeFlags) {
if (NumCachedScopes) {
Scope *N = ScopeCache[--NumCachedScopes];
N->Init(CurScope, ScopeFlags);
CurScope = N;
} else {
CurScope = new Scope(CurScope, ScopeFlags);
}
}
/// ExitScope - Pop a scope off the scope stack.
void Parser::ExitScope() {
assert(CurScope && "Scope imbalance!");
// Inform the actions module that this scope is going away if there are any
// decls in it.
if (!CurScope->decl_empty())
Actions.ActOnPopScope(Tok.getLocation(), CurScope);
Scope *OldScope = CurScope;
CurScope = OldScope->getParent();
if (NumCachedScopes == ScopeCacheSize)
delete OldScope;
else
ScopeCache[NumCachedScopes++] = OldScope;
}
//===----------------------------------------------------------------------===//
// C99 6.9: External Definitions.
//===----------------------------------------------------------------------===//
Parser::~Parser() {
// If we still have scopes active, delete the scope tree.
delete CurScope;
// Free the scope cache.
for (unsigned i = 0, e = NumCachedScopes; i != e; ++i)
delete ScopeCache[i];
// Remove the pragma handlers we installed.
PP.RemovePragmaHandler(0, PackHandler.get());
PackHandler.reset();
PP.RemovePragmaHandler(0, UnusedHandler.get());
UnusedHandler.reset();
PP.RemovePragmaHandler(0, WeakHandler.get());
WeakHandler.reset();
PP.RemoveCommentHandler(CommentHandler.get());
}
/// Initialize - Warm up the parser.
///
void Parser::Initialize() {
// Prime the lexer look-ahead.
ConsumeToken();
// Create the translation unit scope. Install it as the current scope.
assert(CurScope == 0 && "A scope is already active?");
EnterScope(Scope::DeclScope);
Actions.ActOnTranslationUnitScope(Tok.getLocation(), CurScope);
if (Tok.is(tok::eof) &&
!getLang().CPlusPlus) // Empty source file is an extension in C
Diag(Tok, diag::ext_empty_source_file);
// Initialization for Objective-C context sensitive keywords recognition.
// Referenced in Parser::ParseObjCTypeQualifierList.
if (getLang().ObjC1) {
ObjCTypeQuals[objc_in] = &PP.getIdentifierTable().get("in");
ObjCTypeQuals[objc_out] = &PP.getIdentifierTable().get("out");
ObjCTypeQuals[objc_inout] = &PP.getIdentifierTable().get("inout");
ObjCTypeQuals[objc_oneway] = &PP.getIdentifierTable().get("oneway");
ObjCTypeQuals[objc_bycopy] = &PP.getIdentifierTable().get("bycopy");
ObjCTypeQuals[objc_byref] = &PP.getIdentifierTable().get("byref");
}
Ident_super = &PP.getIdentifierTable().get("super");
}
/// ParseTopLevelDecl - Parse one top-level declaration, return whatever the
/// action tells us to. This returns true if the EOF was encountered.
bool Parser::ParseTopLevelDecl(DeclGroupPtrTy &Result) {
Result = DeclGroupPtrTy();
if (Tok.is(tok::eof)) {
Actions.ActOnEndOfTranslationUnit();
return true;
}
Result = ParseExternalDeclaration();
return false;
}
/// ParseTranslationUnit:
/// translation-unit: [C99 6.9]
/// external-declaration
/// translation-unit external-declaration
void Parser::ParseTranslationUnit() {
Initialize();
DeclGroupPtrTy Res;
while (!ParseTopLevelDecl(Res))
/*parse them all*/;
ExitScope();
assert(CurScope == 0 && "Scope imbalance!");
}
/// ParseExternalDeclaration:
///
/// external-declaration: [C99 6.9], declaration: [C++ dcl.dcl]
/// function-definition
/// declaration
/// [C++0x] empty-declaration
/// [GNU] asm-definition
/// [GNU] __extension__ external-declaration
/// [OBJC] objc-class-definition
/// [OBJC] objc-class-declaration
/// [OBJC] objc-alias-declaration
/// [OBJC] objc-protocol-definition
/// [OBJC] objc-method-definition
/// [OBJC] @end
/// [C++] linkage-specification
/// [GNU] asm-definition:
/// simple-asm-expr ';'
///
/// [C++0x] empty-declaration:
/// ';'
///
/// [C++0x/GNU] 'extern' 'template' declaration
Parser::DeclGroupPtrTy Parser::ParseExternalDeclaration() {
DeclPtrTy SingleDecl;
switch (Tok.getKind()) {
case tok::semi:
if (!getLang().CPlusPlus0x)
Diag(Tok, diag::ext_top_level_semi)
<< CodeModificationHint::CreateRemoval(SourceRange(Tok.getLocation()));
ConsumeToken();
// TODO: Invoke action for top-level semicolon.
return DeclGroupPtrTy();
case tok::r_brace:
Diag(Tok, diag::err_expected_external_declaration);
ConsumeBrace();
return DeclGroupPtrTy();
case tok::eof:
Diag(Tok, diag::err_expected_external_declaration);
return DeclGroupPtrTy();
case tok::kw___extension__: {
// __extension__ silences extension warnings in the subexpression.
ExtensionRAIIObject O(Diags); // Use RAII to do this.
ConsumeToken();
return ParseExternalDeclaration();
}
case tok::kw_asm: {
OwningExprResult Result(ParseSimpleAsm());
ExpectAndConsume(tok::semi, diag::err_expected_semi_after,
"top-level asm block");
if (Result.isInvalid())
return DeclGroupPtrTy();
SingleDecl = Actions.ActOnFileScopeAsmDecl(Tok.getLocation(), move(Result));
break;
}
case tok::at:
// @ is not a legal token unless objc is enabled, no need to check for ObjC.
/// FIXME: ParseObjCAtDirectives should return a DeclGroup for things like
/// @class foo, bar;
SingleDecl = ParseObjCAtDirectives();
break;
case tok::minus:
case tok::plus:
if (!getLang().ObjC1) {
Diag(Tok, diag::err_expected_external_declaration);
ConsumeToken();
return DeclGroupPtrTy();
}
SingleDecl = ParseObjCMethodDefinition();
break;
case tok::code_completion:
Actions.CodeCompleteOrdinaryName(CurScope);
ConsumeToken();
return ParseExternalDeclaration();
case tok::kw_using:
case tok::kw_namespace:
case tok::kw_typedef:
case tok::kw_template:
case tok::kw_export: // As in 'export template'
case tok::kw_static_assert:
// A function definition cannot start with a these keywords.
{
SourceLocation DeclEnd;
return ParseDeclaration(Declarator::FileContext, DeclEnd);
}
case tok::kw_extern:
if (getLang().CPlusPlus && NextToken().is(tok::kw_template)) {
// Extern templates
SourceLocation ExternLoc = ConsumeToken();
SourceLocation TemplateLoc = ConsumeToken();
SourceLocation DeclEnd;
return Actions.ConvertDeclToDeclGroup(
ParseExplicitInstantiation(ExternLoc, TemplateLoc, DeclEnd));
}
// FIXME: Detect C++ linkage specifications here?
// Fall through to handle other declarations or function definitions.
default:
// We can't tell whether this is a function-definition or declaration yet.
return ParseDeclarationOrFunctionDefinition();
}
// This routine returns a DeclGroup, if the thing we parsed only contains a
// single decl, convert it now.
return Actions.ConvertDeclToDeclGroup(SingleDecl);
}
/// \brief Determine whether the current token, if it occurs after a
/// declarator, continues a declaration or declaration list.
bool Parser::isDeclarationAfterDeclarator() {
return Tok.is(tok::equal) || // int X()= -> not a function def
Tok.is(tok::comma) || // int X(), -> not a function def
Tok.is(tok::semi) || // int X(); -> not a function def
Tok.is(tok::kw_asm) || // int X() __asm__ -> not a function def
Tok.is(tok::kw___attribute) || // int X() __attr__ -> not a function def
(getLang().CPlusPlus &&
Tok.is(tok::l_paren)); // int X(0) -> not a function def [C++]
}
/// \brief Determine whether the current token, if it occurs after a
/// declarator, indicates the start of a function definition.
bool Parser::isStartOfFunctionDefinition() {
return Tok.is(tok::l_brace) || // int X() {}
(!getLang().CPlusPlus &&
isDeclarationSpecifier()) || // int X(f) int f; {}
(getLang().CPlusPlus &&
(Tok.is(tok::colon) || // X() : Base() {} (used for ctors)
Tok.is(tok::kw_try))); // X() try { ... }
}
/// ParseDeclarationOrFunctionDefinition - Parse either a function-definition or
/// a declaration. We can't tell which we have until we read up to the
/// compound-statement in function-definition. TemplateParams, if
/// non-NULL, provides the template parameters when we're parsing a
/// C++ template-declaration.
///
/// function-definition: [C99 6.9.1]
/// decl-specs declarator declaration-list[opt] compound-statement
/// [C90] function-definition: [C99 6.7.1] - implicit int result
/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement
///
/// declaration: [C99 6.7]
/// declaration-specifiers init-declarator-list[opt] ';'
/// [!C99] init-declarator-list ';' [TODO: warn in c99 mode]
/// [OMP] threadprivate-directive [TODO]
///
Parser::DeclGroupPtrTy
Parser::ParseDeclarationOrFunctionDefinition(AccessSpecifier AS) {
// Parse the common declaration-specifiers piece.
DeclSpec DS;
ParseDeclarationSpecifiers(DS, ParsedTemplateInfo(), AS);
// C99 6.7.2.3p6: Handle "struct-or-union identifier;", "enum { X };"
// declaration-specifiers init-declarator-list[opt] ';'
if (Tok.is(tok::semi)) {
ConsumeToken();
DeclPtrTy TheDecl = Actions.ParsedFreeStandingDeclSpec(CurScope, DS);
return Actions.ConvertDeclToDeclGroup(TheDecl);
}
// ObjC2 allows prefix attributes on class interfaces and protocols.
// FIXME: This still needs better diagnostics. We should only accept
// attributes here, no types, etc.
if (getLang().ObjC2 && Tok.is(tok::at)) {
SourceLocation AtLoc = ConsumeToken(); // the "@"
if (!Tok.isObjCAtKeyword(tok::objc_interface) &&
!Tok.isObjCAtKeyword(tok::objc_protocol)) {
Diag(Tok, diag::err_objc_unexpected_attr);
SkipUntil(tok::semi); // FIXME: better skip?
return DeclGroupPtrTy();
}
const char *PrevSpec = 0;
unsigned DiagID;
if (DS.SetTypeSpecType(DeclSpec::TST_unspecified, AtLoc, PrevSpec, DiagID))
Diag(AtLoc, DiagID) << PrevSpec;
DeclPtrTy TheDecl;
if (Tok.isObjCAtKeyword(tok::objc_protocol))
TheDecl = ParseObjCAtProtocolDeclaration(AtLoc, DS.getAttributes());
else
TheDecl = ParseObjCAtInterfaceDeclaration(AtLoc, DS.getAttributes());
return Actions.ConvertDeclToDeclGroup(TheDecl);
}
// If the declspec consisted only of 'extern' and we have a string
// literal following it, this must be a C++ linkage specifier like
// 'extern "C"'.
if (Tok.is(tok::string_literal) && getLang().CPlusPlus &&
DS.getStorageClassSpec() == DeclSpec::SCS_extern &&
DS.getParsedSpecifiers() == DeclSpec::PQ_StorageClassSpecifier) {
DeclPtrTy TheDecl = ParseLinkage(Declarator::FileContext);
return Actions.ConvertDeclToDeclGroup(TheDecl);
}
// Parse the first declarator.
Declarator DeclaratorInfo(DS, Declarator::FileContext);
ParseDeclarator(DeclaratorInfo);
// Error parsing the declarator?
if (!DeclaratorInfo.hasName()) {
// If so, skip until the semi-colon or a }.
SkipUntil(tok::r_brace, true, true);
if (Tok.is(tok::semi))
ConsumeToken();
return DeclGroupPtrTy();
}
// If we have a declaration or declarator list, handle it.
if (isDeclarationAfterDeclarator()) {
// Parse the init-declarator-list for a normal declaration.
DeclGroupPtrTy DG =
ParseInitDeclaratorListAfterFirstDeclarator(DeclaratorInfo);
// Eat the semi colon after the declaration.
ExpectAndConsume(tok::semi, diag::err_expected_semi_declaration);
return DG;
}
if (DeclaratorInfo.isFunctionDeclarator() &&
isStartOfFunctionDefinition()) {
if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef) {
Diag(Tok, diag::err_function_declared_typedef);
if (Tok.is(tok::l_brace)) {
// This recovery skips the entire function body. It would be nice
// to simply call ParseFunctionDefinition() below, however Sema
// assumes the declarator represents a function, not a typedef.
ConsumeBrace();
SkipUntil(tok::r_brace, true);
} else {
SkipUntil(tok::semi);
}
return DeclGroupPtrTy();
}
DeclPtrTy TheDecl = ParseFunctionDefinition(DeclaratorInfo);
return Actions.ConvertDeclToDeclGroup(TheDecl);
}
if (DeclaratorInfo.isFunctionDeclarator())
Diag(Tok, diag::err_expected_fn_body);
else
Diag(Tok, diag::err_invalid_token_after_toplevel_declarator);
SkipUntil(tok::semi);
return DeclGroupPtrTy();
}
/// ParseFunctionDefinition - We parsed and verified that the specified
/// Declarator is well formed. If this is a K&R-style function, read the
/// parameters declaration-list, then start the compound-statement.
///
/// function-definition: [C99 6.9.1]
/// decl-specs declarator declaration-list[opt] compound-statement
/// [C90] function-definition: [C99 6.7.1] - implicit int result
/// [C90] decl-specs[opt] declarator declaration-list[opt] compound-statement
/// [C++] function-definition: [C++ 8.4]
/// decl-specifier-seq[opt] declarator ctor-initializer[opt]
/// function-body
/// [C++] function-definition: [C++ 8.4]
/// decl-specifier-seq[opt] declarator function-try-block
///
Parser::DeclPtrTy Parser::ParseFunctionDefinition(Declarator &D,
const ParsedTemplateInfo &TemplateInfo) {
const DeclaratorChunk &FnTypeInfo = D.getTypeObject(0);
assert(FnTypeInfo.Kind == DeclaratorChunk::Function &&
"This isn't a function declarator!");
const DeclaratorChunk::FunctionTypeInfo &FTI = FnTypeInfo.Fun;
// If this is C90 and the declspecs were completely missing, fudge in an
// implicit int. We do this here because this is the only place where
// declaration-specifiers are completely optional in the grammar.
if (getLang().ImplicitInt && D.getDeclSpec().isEmpty()) {
const char *PrevSpec;
unsigned DiagID;
D.getMutableDeclSpec().SetTypeSpecType(DeclSpec::TST_int,
D.getIdentifierLoc(),
PrevSpec, DiagID);
D.SetRangeBegin(D.getDeclSpec().getSourceRange().getBegin());
}
// If this declaration was formed with a K&R-style identifier list for the
// arguments, parse declarations for all of the args next.
// int foo(a,b) int a; float b; {}
if (!FTI.hasPrototype && FTI.NumArgs != 0)
ParseKNRParamDeclarations(D);
// We should have either an opening brace or, in a C++ constructor,
// we may have a colon.
if (Tok.isNot(tok::l_brace) && Tok.isNot(tok::colon) &&
Tok.isNot(tok::kw_try)) {
Diag(Tok, diag::err_expected_fn_body);
// Skip over garbage, until we get to '{'. Don't eat the '{'.
SkipUntil(tok::l_brace, true, true);
// If we didn't find the '{', bail out.
if (Tok.isNot(tok::l_brace))
return DeclPtrTy();
}
// Enter a scope for the function body.
ParseScope BodyScope(this, Scope::FnScope|Scope::DeclScope);
// Tell the actions module that we have entered a function definition with the
// specified Declarator for the function.
DeclPtrTy Res = TemplateInfo.TemplateParams?
Actions.ActOnStartOfFunctionTemplateDef(CurScope,
Action::MultiTemplateParamsArg(Actions,
TemplateInfo.TemplateParams->data(),
TemplateInfo.TemplateParams->size()),
D)
: Actions.ActOnStartOfFunctionDef(CurScope, D);
if (Tok.is(tok::kw_try))
return ParseFunctionTryBlock(Res);
// If we have a colon, then we're probably parsing a C++
// ctor-initializer.
if (Tok.is(tok::colon))
ParseConstructorInitializer(Res);
else
Actions.ActOnDefaultCtorInitializers(Res);
return ParseFunctionStatementBody(Res);
}
/// ParseKNRParamDeclarations - Parse 'declaration-list[opt]' which provides
/// types for a function with a K&R-style identifier list for arguments.
void Parser::ParseKNRParamDeclarations(Declarator &D) {
// We know that the top-level of this declarator is a function.
DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(0).Fun;
// Enter function-declaration scope, limiting any declarators to the
// function prototype scope, including parameter declarators.
ParseScope PrototypeScope(this, Scope::FunctionPrototypeScope|Scope::DeclScope);
// Read all the argument declarations.
while (isDeclarationSpecifier()) {
SourceLocation DSStart = Tok.getLocation();
// Parse the common declaration-specifiers piece.
DeclSpec DS;
ParseDeclarationSpecifiers(DS);
// C99 6.9.1p6: 'each declaration in the declaration list shall have at
// least one declarator'.
// NOTE: GCC just makes this an ext-warn. It's not clear what it does with
// the declarations though. It's trivial to ignore them, really hard to do
// anything else with them.
if (Tok.is(tok::semi)) {
Diag(DSStart, diag::err_declaration_does_not_declare_param);
ConsumeToken();
continue;
}
// C99 6.9.1p6: Declarations shall contain no storage-class specifiers other
// than register.
if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
DS.getStorageClassSpec() != DeclSpec::SCS_register) {
Diag(DS.getStorageClassSpecLoc(),
diag::err_invalid_storage_class_in_func_decl);
DS.ClearStorageClassSpecs();
}
if (DS.isThreadSpecified()) {
Diag(DS.getThreadSpecLoc(),
diag::err_invalid_storage_class_in_func_decl);
DS.ClearStorageClassSpecs();
}
// Parse the first declarator attached to this declspec.
Declarator ParmDeclarator(DS, Declarator::KNRTypeListContext);
ParseDeclarator(ParmDeclarator);
// Handle the full declarator list.
while (1) {
Action::AttrTy *AttrList;
// If attributes are present, parse them.
if (Tok.is(tok::kw___attribute))
// FIXME: attach attributes too.
AttrList = ParseAttributes();
// Ask the actions module to compute the type for this declarator.
Action::DeclPtrTy Param =
Actions.ActOnParamDeclarator(CurScope, ParmDeclarator);
if (Param &&
// A missing identifier has already been diagnosed.
ParmDeclarator.getIdentifier()) {
// Scan the argument list looking for the correct param to apply this
// type.
for (unsigned i = 0; ; ++i) {
// C99 6.9.1p6: those declarators shall declare only identifiers from
// the identifier list.
if (i == FTI.NumArgs) {
Diag(ParmDeclarator.getIdentifierLoc(), diag::err_no_matching_param)
<< ParmDeclarator.getIdentifier();
break;
}
if (FTI.ArgInfo[i].Ident == ParmDeclarator.getIdentifier()) {
// Reject redefinitions of parameters.
if (FTI.ArgInfo[i].Param) {
Diag(ParmDeclarator.getIdentifierLoc(),
diag::err_param_redefinition)
<< ParmDeclarator.getIdentifier();
} else {
FTI.ArgInfo[i].Param = Param;
}
break;
}
}
}
// If we don't have a comma, it is either the end of the list (a ';') or
// an error, bail out.
if (Tok.isNot(tok::comma))
break;
// Consume the comma.
ConsumeToken();
// Parse the next declarator.
ParmDeclarator.clear();
ParseDeclarator(ParmDeclarator);
}
if (Tok.is(tok::semi)) {
ConsumeToken();
} else {
Diag(Tok, diag::err_parse_error);
// Skip to end of block or statement
SkipUntil(tok::semi, true);
if (Tok.is(tok::semi))
ConsumeToken();
}
}
// The actions module must verify that all arguments were declared.
Actions.ActOnFinishKNRParamDeclarations(CurScope, D, Tok.getLocation());
}
/// ParseAsmStringLiteral - This is just a normal string-literal, but is not
/// allowed to be a wide string, and is not subject to character translation.
///
/// [GNU] asm-string-literal:
/// string-literal
///
Parser::OwningExprResult Parser::ParseAsmStringLiteral() {
if (!isTokenStringLiteral()) {
Diag(Tok, diag::err_expected_string_literal);
return ExprError();
}
OwningExprResult Res(ParseStringLiteralExpression());
if (Res.isInvalid()) return move(Res);
// TODO: Diagnose: wide string literal in 'asm'
return move(Res);
}
/// ParseSimpleAsm
///
/// [GNU] simple-asm-expr:
/// 'asm' '(' asm-string-literal ')'
///
Parser::OwningExprResult Parser::ParseSimpleAsm(SourceLocation *EndLoc) {
assert(Tok.is(tok::kw_asm) && "Not an asm!");
SourceLocation Loc = ConsumeToken();
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "asm";
return ExprError();
}
Loc = ConsumeParen();
OwningExprResult Result(ParseAsmStringLiteral());
if (Result.isInvalid()) {
SkipUntil(tok::r_paren, true, true);
if (EndLoc)
*EndLoc = Tok.getLocation();
ConsumeAnyToken();
} else {
Loc = MatchRHSPunctuation(tok::r_paren, Loc);
if (EndLoc)
*EndLoc = Loc;
}
return move(Result);
}
/// TryAnnotateTypeOrScopeToken - If the current token position is on a
/// typename (possibly qualified in C++) or a C++ scope specifier not followed
/// by a typename, TryAnnotateTypeOrScopeToken will replace one or more tokens
/// with a single annotation token representing the typename or C++ scope
/// respectively.
/// This simplifies handling of C++ scope specifiers and allows efficient
/// backtracking without the need to re-parse and resolve nested-names and
/// typenames.
/// It will mainly be called when we expect to treat identifiers as typenames
/// (if they are typenames). For example, in C we do not expect identifiers
/// inside expressions to be treated as typenames so it will not be called
/// for expressions in C.
/// The benefit for C/ObjC is that a typename will be annotated and
/// Actions.getTypeName will not be needed to be called again (e.g. getTypeName
/// will not be called twice, once to check whether we have a declaration
/// specifier, and another one to get the actual type inside
/// ParseDeclarationSpecifiers).
///
/// This returns true if the token was annotated or an unrecoverable error
/// occurs.
///
/// Note that this routine emits an error if you call it with ::new or ::delete
/// as the current tokens, so only call it in contexts where these are invalid.
bool Parser::TryAnnotateTypeOrScopeToken(bool EnteringContext) {
assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon)
|| Tok.is(tok::kw_typename)) &&
"Cannot be a type or scope token!");
if (Tok.is(tok::kw_typename)) {
// Parse a C++ typename-specifier, e.g., "typename T::type".
//
// typename-specifier:
// 'typename' '::' [opt] nested-name-specifier identifier
// 'typename' '::' [opt] nested-name-specifier template [opt]
// simple-template-id
SourceLocation TypenameLoc = ConsumeToken();
CXXScopeSpec SS;
bool HadNestedNameSpecifier
= ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false);
if (!HadNestedNameSpecifier) {
Diag(Tok.getLocation(), diag::err_expected_qualified_after_typename);
return false;
}
TypeResult Ty;
if (Tok.is(tok::identifier)) {
// FIXME: check whether the next token is '<', first!
Ty = Actions.ActOnTypenameType(TypenameLoc, SS, *Tok.getIdentifierInfo(),
Tok.getLocation());
} else if (Tok.is(tok::annot_template_id)) {
TemplateIdAnnotation *TemplateId
= static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue());
if (TemplateId->Kind == TNK_Function_template) {
Diag(Tok, diag::err_typename_refers_to_non_type_template)
<< Tok.getAnnotationRange();
return false;
}
AnnotateTemplateIdTokenAsType(0);
assert(Tok.is(tok::annot_typename) &&
"AnnotateTemplateIdTokenAsType isn't working properly");
if (Tok.getAnnotationValue())
Ty = Actions.ActOnTypenameType(TypenameLoc, SS, SourceLocation(),
Tok.getAnnotationValue());
else
Ty = true;
} else {
Diag(Tok, diag::err_expected_type_name_after_typename)
<< SS.getRange();
return false;
}
Tok.setKind(tok::annot_typename);
Tok.setAnnotationValue(Ty.isInvalid()? 0 : Ty.get());
Tok.setAnnotationEndLoc(Tok.getLocation());
Tok.setLocation(TypenameLoc);
PP.AnnotateCachedTokens(Tok);
return true;
}
CXXScopeSpec SS;
if (getLang().CPlusPlus)
ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext);
if (Tok.is(tok::identifier)) {
// Determine whether the identifier is a type name.
if (TypeTy *Ty = Actions.getTypeName(*Tok.getIdentifierInfo(),
Tok.getLocation(), CurScope, &SS)) {
// This is a typename. Replace the current token in-place with an
// annotation type token.
Tok.setKind(tok::annot_typename);
Tok.setAnnotationValue(Ty);
Tok.setAnnotationEndLoc(Tok.getLocation());
if (SS.isNotEmpty()) // it was a C++ qualified type name.
Tok.setLocation(SS.getBeginLoc());
// In case the tokens were cached, have Preprocessor replace
// them with the annotation token.
PP.AnnotateCachedTokens(Tok);
return true;
}
if (!getLang().CPlusPlus) {
// If we're in C, we can't have :: tokens at all (the lexer won't return
// them). If the identifier is not a type, then it can't be scope either,
// just early exit.
return false;
}
// If this is a template-id, annotate with a template-id or type token.
if (NextToken().is(tok::less)) {
TemplateTy Template;
if (TemplateNameKind TNK
= Actions.isTemplateName(CurScope, *Tok.getIdentifierInfo(),
Tok.getLocation(), &SS,
/*ObjectType=*/0, EnteringContext,
Template))
if (AnnotateTemplateIdToken(Template, TNK, &SS)) {
// If an unrecoverable error occurred, we need to return true here,
// because the token stream is in a damaged state. We may not return
// a valid identifier.
return Tok.isNot(tok::identifier);
}
}
// The current token, which is either an identifier or a
// template-id, is not part of the annotation. Fall through to
// push that token back into the stream and complete the C++ scope
// specifier annotation.
}
if (Tok.is(tok::annot_template_id)) {
TemplateIdAnnotation *TemplateId
= static_cast<TemplateIdAnnotation *>(Tok.getAnnotationValue());
if (TemplateId->Kind == TNK_Type_template) {
// A template-id that refers to a type was parsed into a
// template-id annotation in a context where we weren't allowed
// to produce a type annotation token. Update the template-id
// annotation token to a type annotation token now.
AnnotateTemplateIdTokenAsType(&SS);
return true;
}
}
if (SS.isEmpty())
return Tok.isNot(tok::identifier) && Tok.isNot(tok::coloncolon);
// A C++ scope specifier that isn't followed by a typename.
// Push the current token back into the token stream (or revert it if it is
// cached) and use an annotation scope token for current token.
if (PP.isBacktrackEnabled())
PP.RevertCachedTokens(1);
else
PP.EnterToken(Tok);
Tok.setKind(tok::annot_cxxscope);
Tok.setAnnotationValue(SS.getScopeRep());
Tok.setAnnotationRange(SS.getRange());
// In case the tokens were cached, have Preprocessor replace them with the
// annotation token.
PP.AnnotateCachedTokens(Tok);
return true;
}
/// TryAnnotateScopeToken - Like TryAnnotateTypeOrScopeToken but only
/// annotates C++ scope specifiers and template-ids. This returns
/// true if the token was annotated or there was an error that could not be
/// recovered from.
///
/// Note that this routine emits an error if you call it with ::new or ::delete
/// as the current tokens, so only call it in contexts where these are invalid.
bool Parser::TryAnnotateCXXScopeToken(bool EnteringContext) {
assert(getLang().CPlusPlus &&
"Call sites of this function should be guarded by checking for C++");
assert((Tok.is(tok::identifier) || Tok.is(tok::coloncolon)) &&
"Cannot be a type or scope token!");
CXXScopeSpec SS;
if (!ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, EnteringContext))
return Tok.is(tok::annot_template_id);
// Push the current token back into the token stream (or revert it if it is
// cached) and use an annotation scope token for current token.
if (PP.isBacktrackEnabled())
PP.RevertCachedTokens(1);
else
PP.EnterToken(Tok);
Tok.setKind(tok::annot_cxxscope);
Tok.setAnnotationValue(SS.getScopeRep());
Tok.setAnnotationRange(SS.getRange());
// In case the tokens were cached, have Preprocessor replace them with the
// annotation token.
PP.AnnotateCachedTokens(Tok);
return true;
}
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