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clang/lib/Parse/ParseStmt.cpp

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//===--- ParseStmt.cpp - Statement and Block 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 Statement and Block portions of the Parser
// interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Parse/Parser.h"
#include "RAIIObjectsForParser.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/PrettyDeclStackTrace.h"
#include "clang/Sema/Scope.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/PrettyStackTrace.h"
#include "clang/Basic/SourceManager.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// C99 6.8: Statements and Blocks.
//===----------------------------------------------------------------------===//
/// ParseStatementOrDeclaration - Read 'statement' or 'declaration'.
/// StatementOrDeclaration:
/// statement
/// declaration
///
/// statement:
/// labeled-statement
/// compound-statement
/// expression-statement
/// selection-statement
/// iteration-statement
/// jump-statement
/// [C++] declaration-statement
/// [C++] try-block
/// [OBC] objc-throw-statement
/// [OBC] objc-try-catch-statement
/// [OBC] objc-synchronized-statement
/// [GNU] asm-statement
/// [OMP] openmp-construct [TODO]
///
/// labeled-statement:
/// identifier ':' statement
/// 'case' constant-expression ':' statement
/// 'default' ':' statement
///
/// selection-statement:
/// if-statement
/// switch-statement
///
/// iteration-statement:
/// while-statement
/// do-statement
/// for-statement
///
/// expression-statement:
/// expression[opt] ';'
///
/// jump-statement:
/// 'goto' identifier ';'
/// 'continue' ';'
/// 'break' ';'
/// 'return' expression[opt] ';'
/// [GNU] 'goto' '*' expression ';'
///
/// [OBC] objc-throw-statement:
/// [OBC] '@' 'throw' expression ';'
/// [OBC] '@' 'throw' ';'
///
StmtResult
Parser::ParseStatementOrDeclaration(StmtVector &Stmts, bool OnlyStatement) {
const char *SemiError = 0;
StmtResult Res;
ParenBraceBracketBalancer BalancerRAIIObj(*this);
ParsedAttributesWithRange attrs;
MaybeParseCXX0XAttributes(attrs);
// Cases in this switch statement should fall through if the parser expects
// the token to end in a semicolon (in which case SemiError should be set),
// or they directly 'return;' if not.
tok::TokenKind Kind = Tok.getKind();
SourceLocation AtLoc;
switch (Kind) {
case tok::at: // May be a @try or @throw statement
{
AtLoc = ConsumeToken(); // consume @
return ParseObjCAtStatement(AtLoc);
}
case tok::code_completion:
Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement);
ConsumeCodeCompletionToken();
return ParseStatementOrDeclaration(Stmts, OnlyStatement);
case tok::identifier:
if (NextToken().is(tok::colon)) { // C99 6.8.1: labeled-statement
// identifier ':' statement
return ParseLabeledStatement(attrs);
}
// PASS THROUGH.
default: {
if ((getLang().CPlusPlus || !OnlyStatement) && isDeclarationStatement()) {
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy Decl = ParseDeclaration(Stmts, Declarator::BlockContext,
DeclEnd, attrs);
return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);
}
if (Tok.is(tok::r_brace)) {
Diag(Tok, diag::err_expected_statement);
return StmtError();
}
// FIXME: Use the attributes
// expression[opt] ';'
ExprResult Expr(ParseExpression());
if (Expr.isInvalid()) {
// If the expression is invalid, skip ahead to the next semicolon or '}'.
// Not doing this opens us up to the possibility of infinite loops if
// ParseExpression does not consume any tokens.
SkipUntil(tok::r_brace, /*StopAtSemi=*/true, /*DontConsume=*/true);
if (Tok.is(tok::semi))
ConsumeToken();
return StmtError();
}
// Otherwise, eat the semicolon.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
return Actions.ActOnExprStmt(Actions.MakeFullExpr(Expr.get()));
}
case tok::kw_case: // C99 6.8.1: labeled-statement
return ParseCaseStatement(attrs);
case tok::kw_default: // C99 6.8.1: labeled-statement
return ParseDefaultStatement(attrs);
case tok::l_brace: // C99 6.8.2: compound-statement
return ParseCompoundStatement(attrs);
case tok::semi: { // C99 6.8.3p3: expression[opt] ';'
bool LeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
return Actions.ActOnNullStmt(ConsumeToken(), LeadingEmptyMacro);
}
case tok::kw_if: // C99 6.8.4.1: if-statement
return ParseIfStatement(attrs);
case tok::kw_switch: // C99 6.8.4.2: switch-statement
return ParseSwitchStatement(attrs);
case tok::kw_while: // C99 6.8.5.1: while-statement
return ParseWhileStatement(attrs);
case tok::kw_do: // C99 6.8.5.2: do-statement
Res = ParseDoStatement(attrs);
SemiError = "do/while";
break;
case tok::kw_for: // C99 6.8.5.3: for-statement
return ParseForStatement(attrs);
case tok::kw_goto: // C99 6.8.6.1: goto-statement
Res = ParseGotoStatement(attrs);
SemiError = "goto";
break;
case tok::kw_continue: // C99 6.8.6.2: continue-statement
Res = ParseContinueStatement(attrs);
SemiError = "continue";
break;
case tok::kw_break: // C99 6.8.6.3: break-statement
Res = ParseBreakStatement(attrs);
SemiError = "break";
break;
case tok::kw_return: // C99 6.8.6.4: return-statement
Res = ParseReturnStatement(attrs);
SemiError = "return";
break;
case tok::kw_asm: {
ProhibitAttributes(attrs);
bool msAsm = false;
Res = ParseAsmStatement(msAsm);
Res = Actions.ActOnFinishFullStmt(Res.get());
if (msAsm) return move(Res);
SemiError = "asm";
break;
}
case tok::kw_try: // C++ 15: try-block
return ParseCXXTryBlock(attrs);
}
// If we reached this code, the statement must end in a semicolon.
if (Tok.is(tok::semi)) {
ConsumeToken();
} else if (!Res.isInvalid()) {
// If the result was valid, then we do want to diagnose this. Use
// ExpectAndConsume to emit the diagnostic, even though we know it won't
// succeed.
ExpectAndConsume(tok::semi, diag::err_expected_semi_after_stmt, SemiError);
// Skip until we see a } or ;, but don't eat it.
SkipUntil(tok::r_brace, true, true);
}
return move(Res);
}
/// ParseLabeledStatement - We have an identifier and a ':' after it.
///
/// labeled-statement:
/// identifier ':' statement
/// [GNU] identifier ':' attributes[opt] statement
///
StmtResult Parser::ParseLabeledStatement(ParsedAttributes &attrs) {
assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
"Not an identifier!");
Token IdentTok = Tok; // Save the whole token.
ConsumeToken(); // eat the identifier.
assert(Tok.is(tok::colon) && "Not a label!");
// identifier ':' statement
SourceLocation ColonLoc = ConsumeToken();
// Read label attributes, if present.
MaybeParseGNUAttributes(attrs);
StmtResult SubStmt(ParseStatement());
// Broken substmt shouldn't prevent the label from being added to the AST.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(ColonLoc);
LabelDecl *LD = Actions.LookupOrCreateLabel(IdentTok.getIdentifierInfo(),
IdentTok.getLocation());
if (AttributeList *Attrs = attrs.getList())
Actions.ProcessDeclAttributeList(Actions.CurScope, LD, Attrs);
return Actions.ActOnLabelStmt(IdentTok.getLocation(), LD, ColonLoc,
SubStmt.get());
}
/// ParseCaseStatement
/// labeled-statement:
/// 'case' constant-expression ':' statement
/// [GNU] 'case' constant-expression '...' constant-expression ':' statement
///
StmtResult Parser::ParseCaseStatement(ParsedAttributes &attrs) {
assert(Tok.is(tok::kw_case) && "Not a case stmt!");
// FIXME: Use attributes?
// It is very very common for code to contain many case statements recursively
// nested, as in (but usually without indentation):
// case 1:
// case 2:
// case 3:
// case 4:
// case 5: etc.
//
// Parsing this naively works, but is both inefficient and can cause us to run
// out of stack space in our recursive descent parser. As a special case,
// flatten this recursion into an iterative loop. This is complex and gross,
// but all the grossness is constrained to ParseCaseStatement (and some
// wierdness in the actions), so this is just local grossness :).
// TopLevelCase - This is the highest level we have parsed. 'case 1' in the
// example above.
StmtResult TopLevelCase(true);
// DeepestParsedCaseStmt - This is the deepest statement we have parsed, which
// gets updated each time a new case is parsed, and whose body is unset so
// far. When parsing 'case 4', this is the 'case 3' node.
StmtTy *DeepestParsedCaseStmt = 0;
// While we have case statements, eat and stack them.
do {
SourceLocation CaseLoc = ConsumeToken(); // eat the 'case'.
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteCase(getCurScope());
ConsumeCodeCompletionToken();
}
/// We don't want to treat 'case x : y' as a potential typo for 'case x::y'.
/// Disable this form of error recovery while we're parsing the case
/// expression.
ColonProtectionRAIIObject ColonProtection(*this);
ExprResult LHS(ParseConstantExpression());
if (LHS.isInvalid()) {
SkipUntil(tok::colon);
return StmtError();
}
// GNU case range extension.
SourceLocation DotDotDotLoc;
ExprResult RHS;
if (Tok.is(tok::ellipsis)) {
Diag(Tok, diag::ext_gnu_case_range);
DotDotDotLoc = ConsumeToken();
RHS = ParseConstantExpression();
if (RHS.isInvalid()) {
SkipUntil(tok::colon);
return StmtError();
}
}
ColonProtection.restore();
SourceLocation ColonLoc;
if (Tok.is(tok::colon)) {
ColonLoc = ConsumeToken();
// Treat "case blah;" as a typo for "case blah:".
} else if (Tok.is(tok::semi)) {
ColonLoc = ConsumeToken();
Diag(ColonLoc, diag::err_expected_colon_after) << "'case'"
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_colon_after) << "'case'"
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
StmtResult Case =
Actions.ActOnCaseStmt(CaseLoc, LHS.get(), DotDotDotLoc,
RHS.get(), ColonLoc);
// If we had a sema error parsing this case, then just ignore it and
// continue parsing the sub-stmt.
if (Case.isInvalid()) {
if (TopLevelCase.isInvalid()) // No parsed case stmts.
return ParseStatement();
// Otherwise, just don't add it as a nested case.
} else {
// If this is the first case statement we parsed, it becomes TopLevelCase.
// Otherwise we link it into the current chain.
Stmt *NextDeepest = Case.get();
if (TopLevelCase.isInvalid())
TopLevelCase = move(Case);
else
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
DeepestParsedCaseStmt = NextDeepest;
}
// Handle all case statements.
} while (Tok.is(tok::kw_case));
assert(!TopLevelCase.isInvalid() && "Should have parsed at least one case!");
// If we found a non-case statement, start by parsing it.
StmtResult SubStmt;
if (Tok.isNot(tok::r_brace)) {
SubStmt = ParseStatement();
} else {
// Nicely diagnose the common error "switch (X) { case 4: }", which is
// not valid.
// FIXME: add insertion hint.
Diag(Tok, diag::err_label_end_of_compound_statement);
SubStmt = true;
}
// Broken sub-stmt shouldn't prevent forming the case statement properly.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(SourceLocation());
// Install the body into the most deeply-nested case.
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
// Return the top level parsed statement tree.
return move(TopLevelCase);
}
/// ParseDefaultStatement
/// labeled-statement:
/// 'default' ':' statement
/// Note that this does not parse the 'statement' at the end.
///
StmtResult Parser::ParseDefaultStatement(ParsedAttributes &attrs) {
//FIXME: Use attributes?
assert(Tok.is(tok::kw_default) && "Not a default stmt!");
SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
SourceLocation ColonLoc;
if (Tok.is(tok::colon)) {
ColonLoc = ConsumeToken();
// Treat "default;" as a typo for "default:".
} else if (Tok.is(tok::semi)) {
ColonLoc = ConsumeToken();
Diag(ColonLoc, diag::err_expected_colon_after) << "'default'"
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_colon_after) << "'default'"
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
// Diagnose the common error "switch (X) {... default: }", which is not valid.
if (Tok.is(tok::r_brace)) {
Diag(Tok, diag::err_label_end_of_compound_statement);
return StmtError();
}
StmtResult SubStmt(ParseStatement());
if (SubStmt.isInvalid())
return StmtError();
return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
SubStmt.get(), getCurScope());
}
/// ParseCompoundStatement - Parse a "{}" block.
///
/// compound-statement: [C99 6.8.2]
/// { block-item-list[opt] }
/// [GNU] { label-declarations block-item-list } [TODO]
///
/// block-item-list:
/// block-item
/// block-item-list block-item
///
/// block-item:
/// declaration
/// [GNU] '__extension__' declaration
/// statement
/// [OMP] openmp-directive [TODO]
///
/// [GNU] label-declarations:
/// [GNU] label-declaration
/// [GNU] label-declarations label-declaration
///
/// [GNU] label-declaration:
/// [GNU] '__label__' identifier-list ';'
///
/// [OMP] openmp-directive: [TODO]
/// [OMP] barrier-directive
/// [OMP] flush-directive
///
StmtResult Parser::ParseCompoundStatement(ParsedAttributes &attrs,
bool isStmtExpr) {
//FIXME: Use attributes?
assert(Tok.is(tok::l_brace) && "Not a compount stmt!");
// Enter a scope to hold everything within the compound stmt. Compound
// statements can always hold declarations.
ParseScope CompoundScope(this, Scope::DeclScope);
// Parse the statements in the body.
return ParseCompoundStatementBody(isStmtExpr);
}
/// ParseCompoundStatementBody - Parse a sequence of statements and invoke the
/// ActOnCompoundStmt action. This expects the '{' to be the current token, and
/// consume the '}' at the end of the block. It does not manipulate the scope
/// stack.
StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
PrettyStackTraceLoc CrashInfo(PP.getSourceManager(),
Tok.getLocation(),
"in compound statement ('{}')");
InMessageExpressionRAIIObject InMessage(*this, false);
SourceLocation LBraceLoc = ConsumeBrace(); // eat the '{'.
StmtVector Stmts(Actions);
// "__label__ X, Y, Z;" is the GNU "Local Label" extension. These are
// only allowed at the start of a compound stmt regardless of the language.
while (Tok.is(tok::kw___label__)) {
SourceLocation LabelLoc = ConsumeToken();
Diag(LabelLoc, diag::ext_gnu_local_label);
llvm::SmallVector<Decl *, 8> DeclsInGroup;
while (1) {
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected_ident);
break;
}
IdentifierInfo *II = Tok.getIdentifierInfo();
SourceLocation IdLoc = ConsumeToken();
DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
if (!Tok.is(tok::comma))
break;
ConsumeToken();
}
DeclSpec DS;
DeclGroupPtrTy Res = Actions.FinalizeDeclaratorGroup(getCurScope(), DS,
DeclsInGroup.data(), DeclsInGroup.size());
StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
ExpectAndConsume(tok::semi, diag::err_expected_semi_declaration);
if (R.isUsable())
Stmts.push_back(R.release());
}
while (Tok.isNot(tok::r_brace) && Tok.isNot(tok::eof)) {
if (Tok.is(tok::annot_pragma_unused)) {
HandlePragmaUnused();
continue;
}
StmtResult R;
if (Tok.isNot(tok::kw___extension__)) {
R = ParseStatementOrDeclaration(Stmts, false);
} else {
// __extension__ can start declarations and it can also be a unary
// operator for expressions. Consume multiple __extension__ markers here
// until we can determine which is which.
// FIXME: This loses extension expressions in the AST!
SourceLocation ExtLoc = ConsumeToken();
while (Tok.is(tok::kw___extension__))
ConsumeToken();
ParsedAttributesWithRange attrs;
MaybeParseCXX0XAttributes(attrs);
// If this is the start of a declaration, parse it as such.
if (isDeclarationStatement()) {
// __extension__ silences extension warnings in the subdeclaration.
// FIXME: Save the __extension__ on the decl as a node somehow?
ExtensionRAIIObject O(Diags);
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy Res = ParseDeclaration(Stmts,
Declarator::BlockContext, DeclEnd,
attrs);
R = Actions.ActOnDeclStmt(Res, DeclStart, DeclEnd);
} else {
// Otherwise this was a unary __extension__ marker.
ExprResult Res(ParseExpressionWithLeadingExtension(ExtLoc));
if (Res.isInvalid()) {
SkipUntil(tok::semi);
continue;
}
// FIXME: Use attributes?
// Eat the semicolon at the end of stmt and convert the expr into a
// statement.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
R = Actions.ActOnExprStmt(Actions.MakeFullExpr(Res.get()));
}
}
if (R.isUsable())
Stmts.push_back(R.release());
}
// We broke out of the while loop because we found a '}' or EOF.
if (Tok.isNot(tok::r_brace)) {
Diag(Tok, diag::err_expected_rbrace);
Diag(LBraceLoc, diag::note_matching) << "{";
return StmtError();
}
SourceLocation RBraceLoc = ConsumeBrace();
return Actions.ActOnCompoundStmt(LBraceLoc, RBraceLoc, move_arg(Stmts),
isStmtExpr);
}
/// ParseParenExprOrCondition:
/// [C ] '(' expression ')'
/// [C++] '(' condition ')' [not allowed if OnlyAllowCondition=true]
///
/// This function parses and performs error recovery on the specified condition
/// or expression (depending on whether we're in C++ or C mode). This function
/// goes out of its way to recover well. It returns true if there was a parser
/// error (the right paren couldn't be found), which indicates that the caller
/// should try to recover harder. It returns false if the condition is
/// successfully parsed. Note that a successful parse can still have semantic
/// errors in the condition.
bool Parser::ParseParenExprOrCondition(ExprResult &ExprResult,
Decl *&DeclResult,
SourceLocation Loc,
bool ConvertToBoolean) {
SourceLocation LParenLoc = ConsumeParen();
if (getLang().CPlusPlus)
ParseCXXCondition(ExprResult, DeclResult, Loc, ConvertToBoolean);
else {
ExprResult = ParseExpression();
DeclResult = 0;
// If required, convert to a boolean value.
if (!ExprResult.isInvalid() && ConvertToBoolean)
ExprResult
= Actions.ActOnBooleanCondition(getCurScope(), Loc, ExprResult.get());
}
// If the parser was confused by the condition and we don't have a ')', try to
// recover by skipping ahead to a semi and bailing out. If condexp is
// semantically invalid but we have well formed code, keep going.
if (ExprResult.isInvalid() && !DeclResult && Tok.isNot(tok::r_paren)) {
SkipUntil(tok::semi);
// Skipping may have stopped if it found the containing ')'. If so, we can
// continue parsing the if statement.
if (Tok.isNot(tok::r_paren))
return true;
}
// Otherwise the condition is valid or the rparen is present.
MatchRHSPunctuation(tok::r_paren, LParenLoc);
return false;
}
/// ParseIfStatement
/// if-statement: [C99 6.8.4.1]
/// 'if' '(' expression ')' statement
/// 'if' '(' expression ')' statement 'else' statement
/// [C++] 'if' '(' condition ')' statement
/// [C++] 'if' '(' condition ')' statement 'else' statement
///
StmtResult Parser::ParseIfStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_if) && "Not an if stmt!");
SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "if";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLang().C99 || getLang().CPlusPlus;
// C99 6.8.4p3 - In C99, the if statement is a block. This is not
// the case for C90.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
ParseScope IfScope(this, Scope::DeclScope | Scope::ControlScope, C99orCXX);
// Parse the condition.
ExprResult CondExp;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(CondExp, CondVar, IfLoc, true))
return StmtError();
FullExprArg FullCondExp(Actions.MakeFullExpr(CondExp.get()));
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
// For C++ we create a scope for the condition and a new scope for
// substatements because:
// -When the 'then' scope exits, we want the condition declaration to still be
// active for the 'else' scope too.
// -Sema will detect name clashes by considering declarations of a
// 'ControlScope' as part of its direct subscope.
// -If we wanted the condition and substatement to be in the same scope, we
// would have to notify ParseStatement not to create a new scope. It's
// simpler to let it create a new scope.
//
ParseScope InnerScope(this, Scope::DeclScope,
C99orCXX && Tok.isNot(tok::l_brace));
// Read the 'then' stmt.
SourceLocation ThenStmtLoc = Tok.getLocation();
StmtResult ThenStmt(ParseStatement());
// Pop the 'if' scope if needed.
InnerScope.Exit();
// If it has an else, parse it.
SourceLocation ElseLoc;
SourceLocation ElseStmtLoc;
StmtResult ElseStmt;
if (Tok.is(tok::kw_else)) {
ElseLoc = ConsumeToken();
ElseStmtLoc = Tok.getLocation();
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do
// this if the body isn't a compound statement to avoid push/pop in common
// cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
ParseScope InnerScope(this, Scope::DeclScope,
C99orCXX && Tok.isNot(tok::l_brace));
ElseStmt = ParseStatement();
// Pop the 'else' scope if needed.
InnerScope.Exit();
}
IfScope.Exit();
// If the condition was invalid, discard the if statement. We could recover
// better by replacing it with a valid expr, but don't do that yet.
if (CondExp.isInvalid() && !CondVar)
return StmtError();
// If the then or else stmt is invalid and the other is valid (and present),
// make turn the invalid one into a null stmt to avoid dropping the other
// part. If both are invalid, return error.
if ((ThenStmt.isInvalid() && ElseStmt.isInvalid()) ||
(ThenStmt.isInvalid() && ElseStmt.get() == 0) ||
(ThenStmt.get() == 0 && ElseStmt.isInvalid())) {
// Both invalid, or one is invalid and other is non-present: return error.
return StmtError();
}
// Now if either are invalid, replace with a ';'.
if (ThenStmt.isInvalid())
ThenStmt = Actions.ActOnNullStmt(ThenStmtLoc);
if (ElseStmt.isInvalid())
ElseStmt = Actions.ActOnNullStmt(ElseStmtLoc);
return Actions.ActOnIfStmt(IfLoc, FullCondExp, CondVar, ThenStmt.get(),
ElseLoc, ElseStmt.get());
}
/// ParseSwitchStatement
/// switch-statement:
/// 'switch' '(' expression ')' statement
/// [C++] 'switch' '(' condition ')' statement
StmtResult Parser::ParseSwitchStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_switch) && "Not a switch stmt!");
SourceLocation SwitchLoc = ConsumeToken(); // eat the 'switch'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "switch";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLang().C99 || getLang().CPlusPlus;
// C99 6.8.4p3 - In C99, the switch statement is a block. This is
// not the case for C90. Start the switch scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
unsigned ScopeFlags = Scope::BreakScope;
if (C99orCXX)
ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
ParseScope SwitchScope(this, ScopeFlags);
// Parse the condition.
ExprResult Cond;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(Cond, CondVar, SwitchLoc, false))
return StmtError();
StmtResult Switch
= Actions.ActOnStartOfSwitchStmt(SwitchLoc, Cond.get(), CondVar);
if (Switch.isInvalid()) {
// Skip the switch body.
// FIXME: This is not optimal recovery, but parsing the body is more
// dangerous due to the presence of case and default statements, which
// will have no place to connect back with the switch.
if (Tok.is(tok::l_brace)) {
ConsumeBrace();
SkipUntil(tok::r_brace, false, false);
} else
SkipUntil(tok::semi);
return move(Switch);
}
// C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.4p1:
// The substatement in a selection-statement (each substatement, in the else
// form of the if statement) implicitly defines a local scope.
//
// See comments in ParseIfStatement for why we create a scope for the
// condition and a new scope for substatement in C++.
//
ParseScope InnerScope(this, Scope::DeclScope,
C99orCXX && Tok.isNot(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement());
// Pop the scopes.
InnerScope.Exit();
SwitchScope.Exit();
if (Body.isInvalid())
// FIXME: Remove the case statement list from the Switch statement.
Body = Actions.ActOnNullStmt(Tok.getLocation());
return Actions.ActOnFinishSwitchStmt(SwitchLoc, Switch.get(), Body.get());
}
/// ParseWhileStatement
/// while-statement: [C99 6.8.5.1]
/// 'while' '(' expression ')' statement
/// [C++] 'while' '(' condition ')' statement
StmtResult Parser::ParseWhileStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_while) && "Not a while stmt!");
SourceLocation WhileLoc = Tok.getLocation();
ConsumeToken(); // eat the 'while'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "while";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLang().C99 || getLang().CPlusPlus;
// C99 6.8.5p5 - In C99, the while statement is a block. This is not
// the case for C90. Start the loop scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
//
unsigned ScopeFlags;
if (C99orCXX)
ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
Scope::DeclScope | Scope::ControlScope;
else
ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
ParseScope WhileScope(this, ScopeFlags);
// Parse the condition.
ExprResult Cond;
Decl *CondVar = 0;
if (ParseParenExprOrCondition(Cond, CondVar, WhileLoc, true))
return StmtError();
FullExprArg FullCond(Actions.MakeFullExpr(Cond.get()));
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
// See comments in ParseIfStatement for why we create a scope for the
// condition and a new scope for substatement in C++.
//
ParseScope InnerScope(this, Scope::DeclScope,
C99orCXX && Tok.isNot(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement());
// Pop the body scope if needed.
InnerScope.Exit();
WhileScope.Exit();
if ((Cond.isInvalid() && !CondVar) || Body.isInvalid())
return StmtError();
return Actions.ActOnWhileStmt(WhileLoc, FullCond, CondVar, Body.get());
}
/// ParseDoStatement
/// do-statement: [C99 6.8.5.2]
/// 'do' statement 'while' '(' expression ')' ';'
/// Note: this lets the caller parse the end ';'.
StmtResult Parser::ParseDoStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_do) && "Not a do stmt!");
SourceLocation DoLoc = ConsumeToken(); // eat the 'do'.
// C99 6.8.5p5 - In C99, the do statement is a block. This is not
// the case for C90. Start the loop scope.
unsigned ScopeFlags;
if (getLang().C99)
ScopeFlags = Scope::BreakScope | Scope::ContinueScope | Scope::DeclScope;
else
ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
ParseScope DoScope(this, ScopeFlags);
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
ParseScope InnerScope(this, Scope::DeclScope,
(getLang().C99 || getLang().CPlusPlus) &&
Tok.isNot(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement());
// Pop the body scope if needed.
InnerScope.Exit();
if (Tok.isNot(tok::kw_while)) {
if (!Body.isInvalid()) {
Diag(Tok, diag::err_expected_while);
Diag(DoLoc, diag::note_matching) << "do";
SkipUntil(tok::semi, false, true);
}
return StmtError();
}
SourceLocation WhileLoc = ConsumeToken();
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "do/while";
SkipUntil(tok::semi, false, true);
return StmtError();
}
// Parse the parenthesized condition.
SourceLocation LPLoc = ConsumeParen();
ExprResult Cond = ParseExpression();
SourceLocation RPLoc = MatchRHSPunctuation(tok::r_paren, LPLoc);
DoScope.Exit();
if (Cond.isInvalid() || Body.isInvalid())
return StmtError();
return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, LPLoc,
Cond.get(), RPLoc);
}
/// ParseForStatement
/// for-statement: [C99 6.8.5.3]
/// 'for' '(' expr[opt] ';' expr[opt] ';' expr[opt] ')' statement
/// 'for' '(' declaration expr[opt] ';' expr[opt] ')' statement
/// [C++] 'for' '(' for-init-statement condition[opt] ';' expression[opt] ')'
/// [C++] statement
/// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
/// [OBJC2] 'for' '(' expr 'in' expr ')' statement
///
/// [C++] for-init-statement:
/// [C++] expression-statement
/// [C++] simple-declaration
///
StmtResult Parser::ParseForStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_for) && "Not a for stmt!");
SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "for";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXXorObjC = getLang().C99 || getLang().CPlusPlus || getLang().ObjC1;
// C99 6.8.5p5 - In C99, the for statement is a block. This is not
// the case for C90. Start the loop scope.
//
// C++ 6.4p3:
// A name introduced by a declaration in a condition is in scope from its
// point of declaration until the end of the substatements controlled by the
// condition.
// C++ 3.3.2p4:
// Names declared in the for-init-statement, and in the condition of if,
// while, for, and switch statements are local to the if, while, for, or
// switch statement (including the controlled statement).
// C++ 6.5.3p1:
// Names declared in the for-init-statement are in the same declarative-region
// as those declared in the condition.
//
unsigned ScopeFlags;
if (C99orCXXorObjC)
ScopeFlags = Scope::BreakScope | Scope::ContinueScope |
Scope::DeclScope | Scope::ControlScope;
else
ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
ParseScope ForScope(this, ScopeFlags);
SourceLocation LParenLoc = ConsumeParen();
ExprResult Value;
bool ForEach = false;
StmtResult FirstPart;
bool SecondPartIsInvalid = false;
FullExprArg SecondPart(Actions);
ExprResult Collection;
FullExprArg ThirdPart(Actions);
Decl *SecondVar = 0;
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteOrdinaryName(getCurScope(),
C99orCXXorObjC? Sema::PCC_ForInit
: Sema::PCC_Expression);
ConsumeCodeCompletionToken();
}
// Parse the first part of the for specifier.
if (Tok.is(tok::semi)) { // for (;
// no first part, eat the ';'.
ConsumeToken();
} else if (isSimpleDeclaration()) { // for (int X = 4;
// Parse declaration, which eats the ';'.
if (!C99orCXXorObjC) // Use of C99-style for loops in C90 mode?
Diag(Tok, diag::ext_c99_variable_decl_in_for_loop);
ParsedAttributesWithRange attrs;
MaybeParseCXX0XAttributes(attrs);
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
StmtVector Stmts(Actions);
DeclGroupPtrTy DG = ParseSimpleDeclaration(Stmts, Declarator::ForContext,
DeclEnd, attrs, false);
FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
if (Tok.is(tok::semi)) { // for (int x = 4;
ConsumeToken();
} else if ((ForEach = isTokIdentifier_in())) {
Actions.ActOnForEachDeclStmt(DG);
// ObjC: for (id x in expr)
ConsumeToken(); // consume 'in'
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteObjCForCollection(getCurScope(), DG);
ConsumeCodeCompletionToken();
}
Collection = ParseExpression();
} else {
Diag(Tok, diag::err_expected_semi_for);
}
} else {
Value = ParseExpression();
ForEach = isTokIdentifier_in();
// Turn the expression into a stmt.
if (!Value.isInvalid()) {
if (ForEach)
FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
else
FirstPart = Actions.ActOnExprStmt(Actions.MakeFullExpr(Value.get()));
}
if (Tok.is(tok::semi)) {
ConsumeToken();
} else if (ForEach) {
ConsumeToken(); // consume 'in'
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteObjCForCollection(getCurScope(), DeclGroupPtrTy());
ConsumeCodeCompletionToken();
}
Collection = ParseExpression();
} else {
if (!Value.isInvalid()) {
Diag(Tok, diag::err_expected_semi_for);
} else {
// Skip until semicolon or rparen, don't consume it.
SkipUntil(tok::r_paren, true, true);
if (Tok.is(tok::semi))
ConsumeToken();
}
}
}
if (!ForEach) {
assert(!SecondPart.get() && "Shouldn't have a second expression yet.");
// Parse the second part of the for specifier.
if (Tok.is(tok::semi)) { // for (...;;
// no second part.
} else if (Tok.is(tok::r_paren)) {
// missing both semicolons.
} else {
ExprResult Second;
if (getLang().CPlusPlus)
ParseCXXCondition(Second, SecondVar, ForLoc, true);
else {
Second = ParseExpression();
if (!Second.isInvalid())
Second = Actions.ActOnBooleanCondition(getCurScope(), ForLoc,
Second.get());
}
SecondPartIsInvalid = Second.isInvalid();
SecondPart = Actions.MakeFullExpr(Second.get());
}
if (Tok.isNot(tok::semi)) {
if (!SecondPartIsInvalid || SecondVar)
Diag(Tok, diag::err_expected_semi_for);
else
// Skip until semicolon or rparen, don't consume it.
SkipUntil(tok::r_paren, true, true);
}
if (Tok.is(tok::semi)) {
ConsumeToken();
}
// Parse the third part of the for specifier.
if (Tok.isNot(tok::r_paren)) { // for (...;...;)
ExprResult Third = ParseExpression();
ThirdPart = Actions.MakeFullExpr(Third.take());
}
}
// Match the ')'.
SourceLocation RParenLoc = MatchRHSPunctuation(tok::r_paren, LParenLoc);
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
// there is no compound stmt. C90 does not have this clause. We only do this
// if the body isn't a compound statement to avoid push/pop in common cases.
//
// C++ 6.5p2:
// The substatement in an iteration-statement implicitly defines a local scope
// which is entered and exited each time through the loop.
//
// See comments in ParseIfStatement for why we create a scope for
// for-init-statement/condition and a new scope for substatement in C++.
//
ParseScope InnerScope(this, Scope::DeclScope,
C99orCXXorObjC && Tok.isNot(tok::l_brace));
// Read the body statement.
StmtResult Body(ParseStatement());
// Pop the body scope if needed.
InnerScope.Exit();
// Leave the for-scope.
ForScope.Exit();
if (Body.isInvalid())
return StmtError();
if (!ForEach)
return Actions.ActOnForStmt(ForLoc, LParenLoc, FirstPart.take(), SecondPart,
SecondVar, ThirdPart, RParenLoc, Body.take());
// FIXME: It isn't clear how to communicate the late destruction of
// C++ temporaries used to create the collection.
return Actions.ActOnObjCForCollectionStmt(ForLoc, LParenLoc, FirstPart.take(),
Collection.take(), RParenLoc,
Body.take());
}
/// ParseGotoStatement
/// jump-statement:
/// 'goto' identifier ';'
/// [GNU] 'goto' '*' expression ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseGotoStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_goto) && "Not a goto stmt!");
SourceLocation GotoLoc = ConsumeToken(); // eat the 'goto'.
StmtResult Res;
if (Tok.is(tok::identifier)) {
LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
Tok.getLocation());
Res = Actions.ActOnGotoStmt(GotoLoc, Tok.getLocation(), LD);
ConsumeToken();
} else if (Tok.is(tok::star)) {
// GNU indirect goto extension.
Diag(Tok, diag::ext_gnu_indirect_goto);
SourceLocation StarLoc = ConsumeToken();
ExprResult R(ParseExpression());
if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
SkipUntil(tok::semi, false, true);
return StmtError();
}
Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.take());
} else {
Diag(Tok, diag::err_expected_ident);
return StmtError();
}
return move(Res);
}
/// ParseContinueStatement
/// jump-statement:
/// 'continue' ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseContinueStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
SourceLocation ContinueLoc = ConsumeToken(); // eat the 'continue'.
return Actions.ActOnContinueStmt(ContinueLoc, getCurScope());
}
/// ParseBreakStatement
/// jump-statement:
/// 'break' ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseBreakStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
}
/// ParseReturnStatement
/// jump-statement:
/// 'return' expression[opt] ';'
StmtResult Parser::ParseReturnStatement(ParsedAttributes &attrs) {
// FIXME: Use attributes?
assert(Tok.is(tok::kw_return) && "Not a return stmt!");
SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
ExprResult R;
if (Tok.isNot(tok::semi)) {
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteReturn(getCurScope());
ConsumeCodeCompletionToken();
SkipUntil(tok::semi, false, true);
return StmtError();
}
// FIXME: This is a hack to allow something like C++0x's generalized
// initializer lists, but only enough of this feature to allow Clang to
// parse libstdc++ 4.5's headers.
if (Tok.is(tok::l_brace) && getLang().CPlusPlus) {
R = ParseInitializer();
if (R.isUsable() && !getLang().CPlusPlus0x)
Diag(R.get()->getLocStart(), diag::ext_generalized_initializer_lists)
<< R.get()->getSourceRange();
} else
R = ParseExpression();
if (R.isInvalid()) { // Skip to the semicolon, but don't consume it.
SkipUntil(tok::semi, false, true);
return StmtError();
}
}
return Actions.ActOnReturnStmt(ReturnLoc, R.take());
}
/// FuzzyParseMicrosoftAsmStatement. When -fms-extensions is enabled, this
/// routine is called to skip/ignore tokens that comprise the MS asm statement.
StmtResult Parser::FuzzyParseMicrosoftAsmStatement(SourceLocation AsmLoc) {
SourceLocation EndLoc;
if (Tok.is(tok::l_brace)) {
unsigned short savedBraceCount = BraceCount;
do {
EndLoc = Tok.getLocation();
ConsumeAnyToken();
} while (BraceCount > savedBraceCount && Tok.isNot(tok::eof));
} else {
// From the MS website: If used without braces, the __asm keyword means
// that the rest of the line is an assembly-language statement.
SourceManager &SrcMgr = PP.getSourceManager();
SourceLocation TokLoc = Tok.getLocation();
unsigned LineNo = SrcMgr.getInstantiationLineNumber(TokLoc);
do {
EndLoc = TokLoc;
ConsumeAnyToken();
TokLoc = Tok.getLocation();
} while ((SrcMgr.getInstantiationLineNumber(TokLoc) == LineNo) &&
Tok.isNot(tok::r_brace) && Tok.isNot(tok::semi) &&
Tok.isNot(tok::eof));
}
Token t;
t.setKind(tok::string_literal);
t.setLiteralData("\"/*FIXME: not done*/\"");
t.clearFlag(Token::NeedsCleaning);
t.setLength(21);
ExprResult AsmString(Actions.ActOnStringLiteral(&t, 1));
ExprVector Constraints(Actions);
ExprVector Exprs(Actions);
ExprVector Clobbers(Actions);
return Actions.ActOnAsmStmt(AsmLoc, true, true, 0, 0, 0,
move_arg(Constraints), move_arg(Exprs),
AsmString.take(), move_arg(Clobbers),
EndLoc, true);
}
/// ParseAsmStatement - Parse a GNU extended asm statement.
/// asm-statement:
/// gnu-asm-statement
/// ms-asm-statement
///
/// [GNU] gnu-asm-statement:
/// 'asm' type-qualifier[opt] '(' asm-argument ')' ';'
///
/// [GNU] asm-argument:
/// asm-string-literal
/// asm-string-literal ':' asm-operands[opt]
/// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
/// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
/// ':' asm-clobbers
///
/// [GNU] asm-clobbers:
/// asm-string-literal
/// asm-clobbers ',' asm-string-literal
///
/// [MS] ms-asm-statement:
/// '__asm' assembly-instruction ';'[opt]
/// '__asm' '{' assembly-instruction-list '}' ';'[opt]
///
/// [MS] assembly-instruction-list:
/// assembly-instruction ';'[opt]
/// assembly-instruction-list ';' assembly-instruction ';'[opt]
///
StmtResult Parser::ParseAsmStatement(bool &msAsm) {
assert(Tok.is(tok::kw_asm) && "Not an asm stmt");
SourceLocation AsmLoc = ConsumeToken();
if (getLang().Microsoft && Tok.isNot(tok::l_paren) && !isTypeQualifier()) {
msAsm = true;
return FuzzyParseMicrosoftAsmStatement(AsmLoc);
}
DeclSpec DS;
SourceLocation Loc = Tok.getLocation();
ParseTypeQualifierListOpt(DS, true, false);
// GNU asms accept, but warn, about type-qualifiers other than volatile.
if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
Diag(Loc, diag::w_asm_qualifier_ignored) << "const";
if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
Diag(Loc, diag::w_asm_qualifier_ignored) << "restrict";
// Remember if this was a volatile asm.
bool isVolatile = DS.getTypeQualifiers() & DeclSpec::TQ_volatile;
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "asm";
SkipUntil(tok::r_paren);
return StmtError();
}
Loc = ConsumeParen();
ExprResult AsmString(ParseAsmStringLiteral());
if (AsmString.isInvalid())
return StmtError();
llvm::SmallVector<IdentifierInfo *, 4> Names;
ExprVector Constraints(Actions);
ExprVector Exprs(Actions);
ExprVector Clobbers(Actions);
if (Tok.is(tok::r_paren)) {
// We have a simple asm expression like 'asm("foo")'.
SourceLocation RParenLoc = ConsumeParen();
return Actions.ActOnAsmStmt(AsmLoc, /*isSimple*/ true, isVolatile,
/*NumOutputs*/ 0, /*NumInputs*/ 0, 0,
move_arg(Constraints), move_arg(Exprs),
AsmString.take(), move_arg(Clobbers),
RParenLoc);
}
// Parse Outputs, if present.
bool AteExtraColon = false;
if (Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
// In C++ mode, parse "::" like ": :".
AteExtraColon = Tok.is(tok::coloncolon);
ConsumeToken();
if (!AteExtraColon &&
ParseAsmOperandsOpt(Names, Constraints, Exprs))
return StmtError();
}
unsigned NumOutputs = Names.size();
// Parse Inputs, if present.
if (AteExtraColon ||
Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
// In C++ mode, parse "::" like ": :".
if (AteExtraColon)
AteExtraColon = false;
else {
AteExtraColon = Tok.is(tok::coloncolon);
ConsumeToken();
}
if (!AteExtraColon &&
ParseAsmOperandsOpt(Names, Constraints, Exprs))
return StmtError();
}
assert(Names.size() == Constraints.size() &&
Constraints.size() == Exprs.size() &&
"Input operand size mismatch!");
unsigned NumInputs = Names.size() - NumOutputs;
// Parse the clobbers, if present.
if (AteExtraColon || Tok.is(tok::colon)) {
if (!AteExtraColon)
ConsumeToken();
// Parse the asm-string list for clobbers if present.
if (Tok.isNot(tok::r_paren)) {
while (1) {
ExprResult Clobber(ParseAsmStringLiteral());
if (Clobber.isInvalid())
break;
Clobbers.push_back(Clobber.release());
if (Tok.isNot(tok::comma)) break;
ConsumeToken();
}
}
}
SourceLocation RParenLoc = MatchRHSPunctuation(tok::r_paren, Loc);
return Actions.ActOnAsmStmt(AsmLoc, false, isVolatile,
NumOutputs, NumInputs, Names.data(),
move_arg(Constraints), move_arg(Exprs),
AsmString.take(), move_arg(Clobbers),
RParenLoc);
}
/// ParseAsmOperands - Parse the asm-operands production as used by
/// asm-statement, assuming the leading ':' token was eaten.
///
/// [GNU] asm-operands:
/// asm-operand
/// asm-operands ',' asm-operand
///
/// [GNU] asm-operand:
/// asm-string-literal '(' expression ')'
/// '[' identifier ']' asm-string-literal '(' expression ')'
///
//
// FIXME: Avoid unnecessary std::string trashing.
bool Parser::ParseAsmOperandsOpt(llvm::SmallVectorImpl<IdentifierInfo *> &Names,
llvm::SmallVectorImpl<ExprTy *> &Constraints,
llvm::SmallVectorImpl<ExprTy *> &Exprs) {
// 'asm-operands' isn't present?
if (!isTokenStringLiteral() && Tok.isNot(tok::l_square))
return false;
while (1) {
// Read the [id] if present.
if (Tok.is(tok::l_square)) {
SourceLocation Loc = ConsumeBracket();
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected_ident);
SkipUntil(tok::r_paren);
return true;
}
IdentifierInfo *II = Tok.getIdentifierInfo();
ConsumeToken();
Names.push_back(II);
MatchRHSPunctuation(tok::r_square, Loc);
} else
Names.push_back(0);
ExprResult Constraint(ParseAsmStringLiteral());
if (Constraint.isInvalid()) {
SkipUntil(tok::r_paren);
return true;
}
Constraints.push_back(Constraint.release());
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "asm operand";
SkipUntil(tok::r_paren);
return true;
}
// Read the parenthesized expression.
SourceLocation OpenLoc = ConsumeParen();
ExprResult Res(ParseExpression());
MatchRHSPunctuation(tok::r_paren, OpenLoc);
if (Res.isInvalid()) {
SkipUntil(tok::r_paren);
return true;
}
Exprs.push_back(Res.release());
// Eat the comma and continue parsing if it exists.
if (Tok.isNot(tok::comma)) return false;
ConsumeToken();
}
return true;
}
Decl *Parser::ParseFunctionStatementBody(Decl *Decl) {
assert(Tok.is(tok::l_brace));
SourceLocation LBraceLoc = Tok.getLocation();
if (PP.isCodeCompletionEnabled())
if (trySkippingFunctionBodyForCodeCompletion())
return Actions.ActOnFinishFunctionBody(Decl, 0);
PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, LBraceLoc,
"parsing function body");
// Do not enter a scope for the brace, as the arguments are in the same scope
// (the function body) as the body itself. Instead, just read the statement
// list and put it into a CompoundStmt for safe keeping.
StmtResult FnBody(ParseCompoundStatementBody());
// If the function body could not be parsed, make a bogus compoundstmt.
if (FnBody.isInvalid())
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc,
MultiStmtArg(Actions), false);
return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
}
/// ParseFunctionTryBlock - Parse a C++ function-try-block.
///
/// function-try-block:
/// 'try' ctor-initializer[opt] compound-statement handler-seq
///
Decl *Parser::ParseFunctionTryBlock(Decl *Decl) {
assert(Tok.is(tok::kw_try) && "Expected 'try'");
SourceLocation TryLoc = ConsumeToken();
PrettyDeclStackTraceEntry CrashInfo(Actions, Decl, TryLoc,
"parsing function try block");
// Constructor initializer list?
if (Tok.is(tok::colon))
ParseConstructorInitializer(Decl);
if (PP.isCodeCompletionEnabled())
if (trySkippingFunctionBodyForCodeCompletion())
return Actions.ActOnFinishFunctionBody(Decl, 0);
SourceLocation LBraceLoc = Tok.getLocation();
StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc));
// If we failed to parse the try-catch, we just give the function an empty
// compound statement as the body.
if (FnBody.isInvalid())
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc,
MultiStmtArg(Actions), false);
return Actions.ActOnFinishFunctionBody(Decl, FnBody.take());
}
bool Parser::trySkippingFunctionBodyForCodeCompletion() {
assert(Tok.is(tok::l_brace));
assert(PP.isCodeCompletionEnabled() &&
"Should only be called when in code-completion mode");
// We're in code-completion mode. Skip parsing for all function bodies unless
// the body contains the code-completion point.
TentativeParsingAction PA(*this);
ConsumeBrace();
if (SkipUntil(tok::r_brace, /*StopAtSemi=*/false, /*DontConsume=*/false,
/*StopAtCodeCompletion=*/true)) {
PA.Commit();
return true;
}
PA.Revert();
return false;
}
/// ParseCXXTryBlock - Parse a C++ try-block.
///
/// try-block:
/// 'try' compound-statement handler-seq
///
StmtResult Parser::ParseCXXTryBlock(ParsedAttributes &attrs) {
// FIXME: Add attributes?
assert(Tok.is(tok::kw_try) && "Expected 'try'");
SourceLocation TryLoc = ConsumeToken();
return ParseCXXTryBlockCommon(TryLoc);
}
/// ParseCXXTryBlockCommon - Parse the common part of try-block and
/// function-try-block.
///
/// try-block:
/// 'try' compound-statement handler-seq
///
/// function-try-block:
/// 'try' ctor-initializer[opt] compound-statement handler-seq
///
/// handler-seq:
/// handler handler-seq[opt]
///
StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc) {
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected_lbrace));
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
ParsedAttributesWithRange attrs;
StmtResult TryBlock(ParseCompoundStatement(attrs));
if (TryBlock.isInvalid())
return move(TryBlock);
StmtVector Handlers(Actions);
MaybeParseCXX0XAttributes(attrs);
ProhibitAttributes(attrs);
if (Tok.isNot(tok::kw_catch))
return StmtError(Diag(Tok, diag::err_expected_catch));
while (Tok.is(tok::kw_catch)) {
StmtResult Handler(ParseCXXCatchBlock());
if (!Handler.isInvalid())
Handlers.push_back(Handler.release());
}
// Don't bother creating the full statement if we don't have any usable
// handlers.
if (Handlers.empty())
return StmtError();
return Actions.ActOnCXXTryBlock(TryLoc, TryBlock.take(), move_arg(Handlers));
}
/// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
///
/// handler:
/// 'catch' '(' exception-declaration ')' compound-statement
///
/// exception-declaration:
/// type-specifier-seq declarator
/// type-specifier-seq abstract-declarator
/// type-specifier-seq
/// '...'
///
StmtResult Parser::ParseCXXCatchBlock() {
assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
SourceLocation CatchLoc = ConsumeToken();
SourceLocation LParenLoc = Tok.getLocation();
if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen))
return StmtError();
// C++ 3.3.2p3:
// The name in a catch exception-declaration is local to the handler and
// shall not be redeclared in the outermost block of the handler.
ParseScope CatchScope(this, Scope::DeclScope | Scope::ControlScope);
// exception-declaration is equivalent to '...' or a parameter-declaration
// without default arguments.
Decl *ExceptionDecl = 0;
if (Tok.isNot(tok::ellipsis)) {
DeclSpec DS;
if (ParseCXXTypeSpecifierSeq(DS))
return StmtError();
Declarator ExDecl(DS, Declarator::CXXCatchContext);
ParseDeclarator(ExDecl);
ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
} else
ConsumeToken();
if (MatchRHSPunctuation(tok::r_paren, LParenLoc).isInvalid())
return StmtError();
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected_lbrace));
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
ParsedAttributes attrs;
StmtResult Block(ParseCompoundStatement(attrs));
if (Block.isInvalid())
return move(Block);
return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.take());
}
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