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

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//===--- ParseStmt.cpp - Statement and Block Parser -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the Statement and Block portions of the Parser
// interface.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/PrettyDeclStackTrace.h"
#include "clang/Basic/Attributes.h"
#include "clang/Basic/PrettyStackTrace.h"
#include "clang/Parse/LoopHint.h"
#include "clang/Parse/Parser.h"
#include "clang/Parse/RAIIObjectsForParser.h"
#include "clang/Sema/DeclSpec.h"
#include "clang/Sema/Scope.h"
#include "clang/Sema/TypoCorrection.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// C99 6.8: Statements and Blocks.
//===----------------------------------------------------------------------===//
/// Parse a standalone statement (for instance, as the body of an 'if',
/// 'while', or 'for').
StmtResult Parser::ParseStatement(SourceLocation *TrailingElseLoc,
ParsedStmtContext StmtCtx) {
StmtResult Res;
// We may get back a null statement if we found a #pragma. Keep going until
// we get an actual statement.
do {
StmtVector Stmts;
Res = ParseStatementOrDeclaration(Stmts, StmtCtx, TrailingElseLoc);
} while (!Res.isInvalid() && !Res.get());
return Res;
}
/// 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
/// [MS] seh-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,
ParsedStmtContext StmtCtx,
SourceLocation *TrailingElseLoc) {
ParenBraceBracketBalancer BalancerRAIIObj(*this);
ParsedAttributesWithRange Attrs(AttrFactory);
MaybeParseCXX11Attributes(Attrs, nullptr, /*MightBeObjCMessageSend*/ true);
if (!MaybeParseOpenCLUnrollHintAttribute(Attrs))
return StmtError();
StmtResult Res = ParseStatementOrDeclarationAfterAttributes(
Stmts, StmtCtx, TrailingElseLoc, Attrs);
MaybeDestroyTemplateIds();
assert((Attrs.empty() || Res.isInvalid() || Res.isUsable()) &&
"attributes on empty statement");
if (Attrs.empty() || Res.isInvalid())
return Res;
return Actions.ProcessStmtAttributes(Res.get(), Attrs, Attrs.Range);
}
namespace {
class StatementFilterCCC final : public CorrectionCandidateCallback {
public:
StatementFilterCCC(Token nextTok) : NextToken(nextTok) {
WantTypeSpecifiers = nextTok.isOneOf(tok::l_paren, tok::less, tok::l_square,
tok::identifier, tok::star, tok::amp);
WantExpressionKeywords =
nextTok.isOneOf(tok::l_paren, tok::identifier, tok::arrow, tok::period);
WantRemainingKeywords =
nextTok.isOneOf(tok::l_paren, tok::semi, tok::identifier, tok::l_brace);
WantCXXNamedCasts = false;
}
bool ValidateCandidate(const TypoCorrection &candidate) override {
if (FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>())
return !candidate.getCorrectionSpecifier() || isa<ObjCIvarDecl>(FD);
if (NextToken.is(tok::equal))
return candidate.getCorrectionDeclAs<VarDecl>();
if (NextToken.is(tok::period) &&
candidate.getCorrectionDeclAs<NamespaceDecl>())
return false;
return CorrectionCandidateCallback::ValidateCandidate(candidate);
}
std::unique_ptr<CorrectionCandidateCallback> clone() override {
return std::make_unique<StatementFilterCCC>(*this);
}
private:
Token NextToken;
};
}
StmtResult Parser::ParseStatementOrDeclarationAfterAttributes(
StmtVector &Stmts, ParsedStmtContext StmtCtx,
SourceLocation *TrailingElseLoc, ParsedAttributesWithRange &Attrs) {
const char *SemiError = nullptr;
StmtResult Res;
SourceLocation GNUAttributeLoc;
// 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.
Retry:
tok::TokenKind Kind = Tok.getKind();
SourceLocation AtLoc;
switch (Kind) {
case tok::at: // May be a @try or @throw statement
{
ProhibitAttributes(Attrs); // TODO: is it correct?
AtLoc = ConsumeToken(); // consume @
return ParseObjCAtStatement(AtLoc, StmtCtx);
}
case tok::code_completion:
Actions.CodeCompleteOrdinaryName(getCurScope(), Sema::PCC_Statement);
cutOffParsing();
return StmtError();
case tok::identifier: {
Token Next = NextToken();
if (Next.is(tok::colon)) { // C99 6.8.1: labeled-statement
// identifier ':' statement
return ParseLabeledStatement(Attrs, StmtCtx);
}
// Look up the identifier, and typo-correct it to a keyword if it's not
// found.
if (Next.isNot(tok::coloncolon)) {
// Try to limit which sets of keywords should be included in typo
// correction based on what the next token is.
StatementFilterCCC CCC(Next);
if (TryAnnotateName(&CCC) == ANK_Error) {
// Handle errors here by skipping up to the next semicolon or '}', and
// eat the semicolon if that's what stopped us.
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
return StmtError();
}
// If the identifier was typo-corrected, try again.
if (Tok.isNot(tok::identifier))
goto Retry;
}
// Fall through
LLVM_FALLTHROUGH;
}
default: {
if ((getLangOpts().CPlusPlus || getLangOpts().MicrosoftExt ||
(StmtCtx & ParsedStmtContext::AllowDeclarationsInC) !=
ParsedStmtContext()) &&
(GNUAttributeLoc.isValid() || isDeclarationStatement())) {
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy Decl;
if (GNUAttributeLoc.isValid()) {
DeclStart = GNUAttributeLoc;
Decl = ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, Attrs,
&GNUAttributeLoc);
} else {
Decl =
ParseDeclaration(DeclaratorContext::BlockContext, DeclEnd, Attrs);
}
if (Attrs.Range.getBegin().isValid())
DeclStart = Attrs.Range.getBegin();
return Actions.ActOnDeclStmt(Decl, DeclStart, DeclEnd);
}
if (Tok.is(tok::r_brace)) {
Diag(Tok, diag::err_expected_statement);
return StmtError();
}
return ParseExprStatement(StmtCtx);
}
case tok::kw___attribute: {
GNUAttributeLoc = Tok.getLocation();
ParseGNUAttributes(Attrs);
goto Retry;
}
case tok::kw_case: // C99 6.8.1: labeled-statement
return ParseCaseStatement(StmtCtx);
case tok::kw_default: // C99 6.8.1: labeled-statement
return ParseDefaultStatement(StmtCtx);
case tok::l_brace: // C99 6.8.2: compound-statement
return ParseCompoundStatement();
case tok::semi: { // C99 6.8.3p3: expression[opt] ';'
bool HasLeadingEmptyMacro = Tok.hasLeadingEmptyMacro();
return Actions.ActOnNullStmt(ConsumeToken(), HasLeadingEmptyMacro);
}
case tok::kw_if: // C99 6.8.4.1: if-statement
return ParseIfStatement(TrailingElseLoc);
case tok::kw_switch: // C99 6.8.4.2: switch-statement
return ParseSwitchStatement(TrailingElseLoc);
case tok::kw_while: // C99 6.8.5.1: while-statement
return ParseWhileStatement(TrailingElseLoc);
case tok::kw_do: // C99 6.8.5.2: do-statement
Res = ParseDoStatement();
SemiError = "do/while";
break;
case tok::kw_for: // C99 6.8.5.3: for-statement
return ParseForStatement(TrailingElseLoc);
case tok::kw_goto: // C99 6.8.6.1: goto-statement
Res = ParseGotoStatement();
SemiError = "goto";
break;
case tok::kw_continue: // C99 6.8.6.2: continue-statement
Res = ParseContinueStatement();
SemiError = "continue";
break;
case tok::kw_break: // C99 6.8.6.3: break-statement
Res = ParseBreakStatement();
SemiError = "break";
break;
case tok::kw_return: // C99 6.8.6.4: return-statement
Res = ParseReturnStatement();
SemiError = "return";
break;
case tok::kw_co_return: // C++ Coroutines: co_return statement
Res = ParseReturnStatement();
SemiError = "co_return";
break;
case tok::kw_asm: {
ProhibitAttributes(Attrs);
bool msAsm = false;
Res = ParseAsmStatement(msAsm);
Res = Actions.ActOnFinishFullStmt(Res.get());
if (msAsm) return Res;
SemiError = "asm";
break;
}
case tok::kw___if_exists:
case tok::kw___if_not_exists:
ProhibitAttributes(Attrs);
ParseMicrosoftIfExistsStatement(Stmts);
// An __if_exists block is like a compound statement, but it doesn't create
// a new scope.
return StmtEmpty();
case tok::kw_try: // C++ 15: try-block
return ParseCXXTryBlock();
case tok::kw___try:
ProhibitAttributes(Attrs); // TODO: is it correct?
return ParseSEHTryBlock();
case tok::kw___leave:
Res = ParseSEHLeaveStatement();
SemiError = "__leave";
break;
case tok::annot_pragma_vis:
ProhibitAttributes(Attrs);
HandlePragmaVisibility();
return StmtEmpty();
case tok::annot_pragma_pack:
ProhibitAttributes(Attrs);
HandlePragmaPack();
return StmtEmpty();
case tok::annot_pragma_msstruct:
ProhibitAttributes(Attrs);
HandlePragmaMSStruct();
return StmtEmpty();
case tok::annot_pragma_align:
ProhibitAttributes(Attrs);
HandlePragmaAlign();
return StmtEmpty();
case tok::annot_pragma_weak:
ProhibitAttributes(Attrs);
HandlePragmaWeak();
return StmtEmpty();
case tok::annot_pragma_weakalias:
ProhibitAttributes(Attrs);
HandlePragmaWeakAlias();
return StmtEmpty();
case tok::annot_pragma_redefine_extname:
ProhibitAttributes(Attrs);
HandlePragmaRedefineExtname();
return StmtEmpty();
case tok::annot_pragma_fp_contract:
ProhibitAttributes(Attrs);
Diag(Tok, diag::err_pragma_file_or_compound_scope) << "fp_contract";
ConsumeAnnotationToken();
return StmtError();
case tok::annot_pragma_fp:
ProhibitAttributes(Attrs);
Diag(Tok, diag::err_pragma_file_or_compound_scope) << "clang fp";
ConsumeAnnotationToken();
return StmtError();
case tok::annot_pragma_fenv_access:
ProhibitAttributes(Attrs);
HandlePragmaFEnvAccess();
return StmtEmpty();
case tok::annot_pragma_float_control:
ProhibitAttributes(Attrs);
Diag(Tok, diag::err_pragma_file_or_compound_scope) << "float_control";
ConsumeAnnotationToken();
return StmtError();
case tok::annot_pragma_opencl_extension:
ProhibitAttributes(Attrs);
HandlePragmaOpenCLExtension();
return StmtEmpty();
case tok::annot_pragma_captured:
ProhibitAttributes(Attrs);
return HandlePragmaCaptured();
case tok::annot_pragma_openmp:
ProhibitAttributes(Attrs);
return ParseOpenMPDeclarativeOrExecutableDirective(StmtCtx);
case tok::annot_pragma_ms_pointers_to_members:
ProhibitAttributes(Attrs);
HandlePragmaMSPointersToMembers();
return StmtEmpty();
case tok::annot_pragma_ms_pragma:
ProhibitAttributes(Attrs);
HandlePragmaMSPragma();
return StmtEmpty();
case tok::annot_pragma_ms_vtordisp:
ProhibitAttributes(Attrs);
HandlePragmaMSVtorDisp();
return StmtEmpty();
case tok::annot_pragma_loop_hint:
ProhibitAttributes(Attrs);
return ParsePragmaLoopHint(Stmts, StmtCtx, TrailingElseLoc, Attrs);
case tok::annot_pragma_dump:
HandlePragmaDump();
return StmtEmpty();
case tok::annot_pragma_attribute:
HandlePragmaAttribute();
return StmtEmpty();
}
// If we reached this code, the statement must end in a semicolon.
if (!TryConsumeToken(tok::semi) && !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, StopAtSemi | StopBeforeMatch);
}
return Res;
}
/// Parse an expression statement.
StmtResult Parser::ParseExprStatement(ParsedStmtContext StmtCtx) {
// If a case keyword is missing, this is where it should be inserted.
Token OldToken = Tok;
ExprStatementTokLoc = Tok.getLocation();
// 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 | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
return Actions.ActOnExprStmtError();
}
if (Tok.is(tok::colon) && getCurScope()->isSwitchScope() &&
Actions.CheckCaseExpression(Expr.get())) {
// If a constant expression is followed by a colon inside a switch block,
// suggest a missing case keyword.
Diag(OldToken, diag::err_expected_case_before_expression)
<< FixItHint::CreateInsertion(OldToken.getLocation(), "case ");
// Recover parsing as a case statement.
return ParseCaseStatement(StmtCtx, /*MissingCase=*/true, Expr);
}
// Otherwise, eat the semicolon.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
return handleExprStmt(Expr, StmtCtx);
}
/// ParseSEHTryBlockCommon
///
/// seh-try-block:
/// '__try' compound-statement seh-handler
///
/// seh-handler:
/// seh-except-block
/// seh-finally-block
///
StmtResult Parser::ParseSEHTryBlock() {
assert(Tok.is(tok::kw___try) && "Expected '__try'");
SourceLocation TryLoc = ConsumeToken();
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
StmtResult TryBlock(ParseCompoundStatement(
/*isStmtExpr=*/false,
Scope::DeclScope | Scope::CompoundStmtScope | Scope::SEHTryScope));
if (TryBlock.isInvalid())
return TryBlock;
StmtResult Handler;
if (Tok.is(tok::identifier) &&
Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHExceptBlock(Loc);
} else if (Tok.is(tok::kw___finally)) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHFinallyBlock(Loc);
} else {
return StmtError(Diag(Tok, diag::err_seh_expected_handler));
}
if(Handler.isInvalid())
return Handler;
return Actions.ActOnSEHTryBlock(false /* IsCXXTry */,
TryLoc,
TryBlock.get(),
Handler.get());
}
/// ParseSEHExceptBlock - Handle __except
///
/// seh-except-block:
/// '__except' '(' seh-filter-expression ')' compound-statement
///
StmtResult Parser::ParseSEHExceptBlock(SourceLocation ExceptLoc) {
PoisonIdentifierRAIIObject raii(Ident__exception_code, false),
raii2(Ident___exception_code, false),
raii3(Ident_GetExceptionCode, false);
if (ExpectAndConsume(tok::l_paren))
return StmtError();
ParseScope ExpectScope(this, Scope::DeclScope | Scope::ControlScope |
Scope::SEHExceptScope);
if (getLangOpts().Borland) {
Ident__exception_info->setIsPoisoned(false);
Ident___exception_info->setIsPoisoned(false);
Ident_GetExceptionInfo->setIsPoisoned(false);
}
ExprResult FilterExpr;
{
ParseScopeFlags FilterScope(this, getCurScope()->getFlags() |
Scope::SEHFilterScope);
FilterExpr = Actions.CorrectDelayedTyposInExpr(ParseExpression());
}
if (getLangOpts().Borland) {
Ident__exception_info->setIsPoisoned(true);
Ident___exception_info->setIsPoisoned(true);
Ident_GetExceptionInfo->setIsPoisoned(true);
}
if(FilterExpr.isInvalid())
return StmtError();
if (ExpectAndConsume(tok::r_paren))
return StmtError();
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
StmtResult Block(ParseCompoundStatement());
if(Block.isInvalid())
return Block;
return Actions.ActOnSEHExceptBlock(ExceptLoc, FilterExpr.get(), Block.get());
}
/// ParseSEHFinallyBlock - Handle __finally
///
/// seh-finally-block:
/// '__finally' compound-statement
///
StmtResult Parser::ParseSEHFinallyBlock(SourceLocation FinallyLoc) {
PoisonIdentifierRAIIObject raii(Ident__abnormal_termination, false),
raii2(Ident___abnormal_termination, false),
raii3(Ident_AbnormalTermination, false);
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
ParseScope FinallyScope(this, 0);
Actions.ActOnStartSEHFinallyBlock();
StmtResult Block(ParseCompoundStatement());
if(Block.isInvalid()) {
Actions.ActOnAbortSEHFinallyBlock();
return Block;
}
return Actions.ActOnFinishSEHFinallyBlock(FinallyLoc, Block.get());
}
/// Handle __leave
///
/// seh-leave-statement:
/// '__leave' ';'
///
StmtResult Parser::ParseSEHLeaveStatement() {
SourceLocation LeaveLoc = ConsumeToken(); // eat the '__leave'.
return Actions.ActOnSEHLeaveStmt(LeaveLoc, getCurScope());
}
/// ParseLabeledStatement - We have an identifier and a ':' after it.
///
/// labeled-statement:
/// identifier ':' statement
/// [GNU] identifier ':' attributes[opt] statement
///
StmtResult Parser::ParseLabeledStatement(ParsedAttributesWithRange &attrs,
ParsedStmtContext StmtCtx) {
assert(Tok.is(tok::identifier) && Tok.getIdentifierInfo() &&
"Not an identifier!");
// The substatement is always a 'statement', not a 'declaration', but is
// otherwise in the same context as the labeled-statement.
StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
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.
StmtResult SubStmt;
if (Tok.is(tok::kw___attribute)) {
ParsedAttributesWithRange TempAttrs(AttrFactory);
ParseGNUAttributes(TempAttrs);
// In C++, GNU attributes only apply to the label if they are followed by a
// semicolon, to disambiguate label attributes from attributes on a labeled
// declaration.
//
// This doesn't quite match what GCC does; if the attribute list is empty
// and followed by a semicolon, GCC will reject (it appears to parse the
// attributes as part of a statement in that case). That looks like a bug.
if (!getLangOpts().CPlusPlus || Tok.is(tok::semi))
attrs.takeAllFrom(TempAttrs);
else if (isDeclarationStatement()) {
StmtVector Stmts;
// FIXME: We should do this whether or not we have a declaration
// statement, but that doesn't work correctly (because ProhibitAttributes
// can't handle GNU attributes), so only call it in the one case where
// GNU attributes are allowed.
SubStmt = ParseStatementOrDeclarationAfterAttributes(Stmts, StmtCtx,
nullptr, TempAttrs);
if (!TempAttrs.empty() && !SubStmt.isInvalid())
SubStmt = Actions.ProcessStmtAttributes(SubStmt.get(), TempAttrs,
TempAttrs.Range);
} else {
Diag(Tok, diag::err_expected_after) << "__attribute__" << tok::semi;
}
}
// If we've not parsed a statement yet, parse one now.
if (!SubStmt.isInvalid() && !SubStmt.isUsable())
SubStmt = ParseStatement(nullptr, StmtCtx);
// 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());
Actions.ProcessDeclAttributeList(Actions.CurScope, LD, attrs);
attrs.clear();
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(ParsedStmtContext StmtCtx,
bool MissingCase, ExprResult Expr) {
assert((MissingCase || Tok.is(tok::kw_case)) && "Not a case stmt!");
// The substatement is always a 'statement', not a 'declaration', but is
// otherwise in the same context as the labeled-statement.
StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
// 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
// weirdness 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.
Stmt *DeepestParsedCaseStmt = nullptr;
// While we have case statements, eat and stack them.
SourceLocation ColonLoc;
do {
SourceLocation CaseLoc = MissingCase ? Expr.get()->getExprLoc() :
ConsumeToken(); // eat the 'case'.
ColonLoc = SourceLocation();
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteCase(getCurScope());
cutOffParsing();
return StmtError();
}
/// 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;
if (!MissingCase) {
LHS = ParseCaseExpression(CaseLoc);
if (LHS.isInvalid()) {
// If constant-expression is parsed unsuccessfully, recover by skipping
// current case statement (moving to the colon that ends it).
if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch))
return StmtError();
}
} else {
LHS = Expr;
MissingCase = false;
}
// GNU case range extension.
SourceLocation DotDotDotLoc;
ExprResult RHS;
if (TryConsumeToken(tok::ellipsis, DotDotDotLoc)) {
Diag(DotDotDotLoc, diag::ext_gnu_case_range);
RHS = ParseCaseExpression(CaseLoc);
if (RHS.isInvalid()) {
if (!SkipUntil(tok::colon, tok::r_brace, StopAtSemi | StopBeforeMatch))
return StmtError();
}
}
ColonProtection.restore();
if (TryConsumeToken(tok::colon, ColonLoc)) {
} else if (TryConsumeToken(tok::semi, ColonLoc) ||
TryConsumeToken(tok::coloncolon, ColonLoc)) {
// Treat "case blah;" or "case blah::" as a typo for "case blah:".
Diag(ColonLoc, diag::err_expected_after)
<< "'case'" << tok::colon
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_after)
<< "'case'" << tok::colon
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
StmtResult Case =
Actions.ActOnCaseStmt(CaseLoc, LHS, DotDotDotLoc, RHS, 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(/*TrailingElseLoc=*/nullptr, StmtCtx);
// 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 = Case;
else
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, Case.get());
DeepestParsedCaseStmt = NextDeepest;
}
// Handle all case statements.
} while (Tok.is(tok::kw_case));
// If we found a non-case statement, start by parsing it.
StmtResult SubStmt;
if (Tok.isNot(tok::r_brace)) {
SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx);
} else {
// Nicely diagnose the common error "switch (X) { case 4: }", which is
// not valid. If ColonLoc doesn't point to a valid text location, there was
// another parsing error, so avoid producing extra diagnostics.
if (ColonLoc.isValid()) {
SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
<< FixItHint::CreateInsertion(AfterColonLoc, " ;");
}
SubStmt = StmtError();
}
// Install the body into the most deeply-nested case.
if (DeepestParsedCaseStmt) {
// Broken sub-stmt shouldn't prevent forming the case statement properly.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(SourceLocation());
Actions.ActOnCaseStmtBody(DeepestParsedCaseStmt, SubStmt.get());
}
// Return the top level parsed statement tree.
return TopLevelCase;
}
/// ParseDefaultStatement
/// labeled-statement:
/// 'default' ':' statement
/// Note that this does not parse the 'statement' at the end.
///
StmtResult Parser::ParseDefaultStatement(ParsedStmtContext StmtCtx) {
assert(Tok.is(tok::kw_default) && "Not a default stmt!");
// The substatement is always a 'statement', not a 'declaration', but is
// otherwise in the same context as the labeled-statement.
StmtCtx &= ~ParsedStmtContext::AllowDeclarationsInC;
SourceLocation DefaultLoc = ConsumeToken(); // eat the 'default'.
SourceLocation ColonLoc;
if (TryConsumeToken(tok::colon, ColonLoc)) {
} else if (TryConsumeToken(tok::semi, ColonLoc)) {
// Treat "default;" as a typo for "default:".
Diag(ColonLoc, diag::err_expected_after)
<< "'default'" << tok::colon
<< FixItHint::CreateReplacement(ColonLoc, ":");
} else {
SourceLocation ExpectedLoc = PP.getLocForEndOfToken(PrevTokLocation);
Diag(ExpectedLoc, diag::err_expected_after)
<< "'default'" << tok::colon
<< FixItHint::CreateInsertion(ExpectedLoc, ":");
ColonLoc = ExpectedLoc;
}
StmtResult SubStmt;
if (Tok.isNot(tok::r_brace)) {
SubStmt = ParseStatement(/*TrailingElseLoc=*/nullptr, StmtCtx);
} else {
// Diagnose the common error "switch (X) {... default: }", which is
// not valid.
SourceLocation AfterColonLoc = PP.getLocForEndOfToken(ColonLoc);
Diag(AfterColonLoc, diag::err_label_end_of_compound_statement)
<< FixItHint::CreateInsertion(AfterColonLoc, " ;");
SubStmt = true;
}
// Broken sub-stmt shouldn't prevent forming the case statement properly.
if (SubStmt.isInvalid())
SubStmt = Actions.ActOnNullStmt(ColonLoc);
return Actions.ActOnDefaultStmt(DefaultLoc, ColonLoc,
SubStmt.get(), getCurScope());
}
StmtResult Parser::ParseCompoundStatement(bool isStmtExpr) {
return ParseCompoundStatement(isStmtExpr,
Scope::DeclScope | Scope::CompoundStmtScope);
}
/// 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
///
/// [GNU] label-declarations:
/// [GNU] label-declaration
/// [GNU] label-declarations label-declaration
///
/// [GNU] label-declaration:
/// [GNU] '__label__' identifier-list ';'
///
StmtResult Parser::ParseCompoundStatement(bool isStmtExpr,
unsigned ScopeFlags) {
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, ScopeFlags);
// Parse the statements in the body.
return ParseCompoundStatementBody(isStmtExpr);
}
/// Parse any pragmas at the start of the compound expression. We handle these
/// separately since some pragmas (FP_CONTRACT) must appear before any C
/// statement in the compound, but may be intermingled with other pragmas.
void Parser::ParseCompoundStatementLeadingPragmas() {
bool checkForPragmas = true;
while (checkForPragmas) {
switch (Tok.getKind()) {
case tok::annot_pragma_vis:
HandlePragmaVisibility();
break;
case tok::annot_pragma_pack:
HandlePragmaPack();
break;
case tok::annot_pragma_msstruct:
HandlePragmaMSStruct();
break;
case tok::annot_pragma_align:
HandlePragmaAlign();
break;
case tok::annot_pragma_weak:
HandlePragmaWeak();
break;
case tok::annot_pragma_weakalias:
HandlePragmaWeakAlias();
break;
case tok::annot_pragma_redefine_extname:
HandlePragmaRedefineExtname();
break;
case tok::annot_pragma_opencl_extension:
HandlePragmaOpenCLExtension();
break;
case tok::annot_pragma_fp_contract:
HandlePragmaFPContract();
break;
case tok::annot_pragma_fp:
HandlePragmaFP();
break;
case tok::annot_pragma_fenv_access:
HandlePragmaFEnvAccess();
break;
case tok::annot_pragma_float_control:
HandlePragmaFloatControl();
break;
case tok::annot_pragma_ms_pointers_to_members:
HandlePragmaMSPointersToMembers();
break;
case tok::annot_pragma_ms_pragma:
HandlePragmaMSPragma();
break;
case tok::annot_pragma_ms_vtordisp:
HandlePragmaMSVtorDisp();
break;
case tok::annot_pragma_dump:
HandlePragmaDump();
break;
default:
checkForPragmas = false;
break;
}
}
}
/// Consume any extra semi-colons resulting in null statements,
/// returning true if any tok::semi were consumed.
bool Parser::ConsumeNullStmt(StmtVector &Stmts) {
if (!Tok.is(tok::semi))
return false;
SourceLocation StartLoc = Tok.getLocation();
SourceLocation EndLoc;
while (Tok.is(tok::semi) && !Tok.hasLeadingEmptyMacro() &&
Tok.getLocation().isValid() && !Tok.getLocation().isMacroID()) {
EndLoc = Tok.getLocation();
// Don't just ConsumeToken() this tok::semi, do store it in AST.
StmtResult R =
ParseStatementOrDeclaration(Stmts, ParsedStmtContext::SubStmt);
if (R.isUsable())
Stmts.push_back(R.get());
}
// Did not consume any extra semi.
if (EndLoc.isInvalid())
return false;
Diag(StartLoc, diag::warn_null_statement)
<< FixItHint::CreateRemoval(SourceRange(StartLoc, EndLoc));
return true;
}
StmtResult Parser::handleExprStmt(ExprResult E, ParsedStmtContext StmtCtx) {
bool IsStmtExprResult = false;
if ((StmtCtx & ParsedStmtContext::InStmtExpr) != ParsedStmtContext()) {
// For GCC compatibility we skip past NullStmts.
unsigned LookAhead = 0;
while (GetLookAheadToken(LookAhead).is(tok::semi)) {
++LookAhead;
}
// Then look to see if the next two tokens close the statement expression;
// if so, this expression statement is the last statement in a statment
// expression.
IsStmtExprResult = GetLookAheadToken(LookAhead).is(tok::r_brace) &&
GetLookAheadToken(LookAhead + 1).is(tok::r_paren);
}
if (IsStmtExprResult)
E = Actions.ActOnStmtExprResult(E);
return Actions.ActOnExprStmt(E, /*DiscardedValue=*/!IsStmtExprResult);
}
/// 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 ('{}')");
// Record the state of the FPFeatures, restore on leaving the
// compound statement.
Sema::FPFeaturesStateRAII SaveFPContractState(Actions);
InMessageExpressionRAIIObject InMessage(*this, false);
BalancedDelimiterTracker T(*this, tok::l_brace);
if (T.consumeOpen())
return StmtError();
Sema::CompoundScopeRAII CompoundScope(Actions, isStmtExpr);
// Parse any pragmas at the beginning of the compound statement.
ParseCompoundStatementLeadingPragmas();
StmtVector Stmts;
// "__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();
SmallVector<Decl *, 8> DeclsInGroup;
while (1) {
if (Tok.isNot(tok::identifier)) {
Diag(Tok, diag::err_expected) << tok::identifier;
break;
}
IdentifierInfo *II = Tok.getIdentifierInfo();
SourceLocation IdLoc = ConsumeToken();
DeclsInGroup.push_back(Actions.LookupOrCreateLabel(II, IdLoc, LabelLoc));
if (!TryConsumeToken(tok::comma))
break;
}
DeclSpec DS(AttrFactory);
DeclGroupPtrTy Res =
Actions.FinalizeDeclaratorGroup(getCurScope(), DS, DeclsInGroup);
StmtResult R = Actions.ActOnDeclStmt(Res, LabelLoc, Tok.getLocation());
ExpectAndConsumeSemi(diag::err_expected_semi_declaration);
if (R.isUsable())
Stmts.push_back(R.get());
}
ParsedStmtContext SubStmtCtx =
ParsedStmtContext::Compound |
(isStmtExpr ? ParsedStmtContext::InStmtExpr : ParsedStmtContext());
while (!tryParseMisplacedModuleImport() && Tok.isNot(tok::r_brace) &&
Tok.isNot(tok::eof)) {
if (Tok.is(tok::annot_pragma_unused)) {
HandlePragmaUnused();
continue;
}
if (ConsumeNullStmt(Stmts))
continue;
StmtResult R;
if (Tok.isNot(tok::kw___extension__)) {
R = ParseStatementOrDeclaration(Stmts, SubStmtCtx);
} 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(AttrFactory);
MaybeParseCXX11Attributes(attrs, nullptr,
/*MightBeObjCMessageSend*/ true);
// 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(DeclaratorContext::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;
}
// Eat the semicolon at the end of stmt and convert the expr into a
// statement.
ExpectAndConsumeSemi(diag::err_expected_semi_after_expr);
R = handleExprStmt(Res, SubStmtCtx);
if (R.isUsable())
R = Actions.ProcessStmtAttributes(R.get(), attrs, attrs.Range);
}
}
if (R.isUsable())
Stmts.push_back(R.get());
}
SourceLocation CloseLoc = Tok.getLocation();
// We broke out of the while loop because we found a '}' or EOF.
if (!T.consumeClose()) {
// If this is the '})' of a statement expression, check that it's written
// in a sensible way.
if (isStmtExpr && Tok.is(tok::r_paren))
checkCompoundToken(CloseLoc, tok::r_brace, CompoundToken::StmtExprEnd);
} else {
// Recover by creating a compound statement with what we parsed so far,
// instead of dropping everything and returning StmtError().
}
if (T.getCloseLocation().isValid())
CloseLoc = T.getCloseLocation();
return Actions.ActOnCompoundStmt(T.getOpenLocation(), CloseLoc,
Stmts, isStmtExpr);
}
/// ParseParenExprOrCondition:
/// [C ] '(' expression ')'
/// [C++] '(' condition ')'
/// [C++1z] '(' init-statement[opt] condition ')'
///
/// 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.
/// Additionally, if LParenLoc and RParenLoc are non-null, it will assign
/// the location of the outer-most '(' and ')', respectively, to them.
bool Parser::ParseParenExprOrCondition(StmtResult *InitStmt,
Sema::ConditionResult &Cond,
SourceLocation Loc,
Sema::ConditionKind CK,
SourceLocation *LParenLoc,
SourceLocation *RParenLoc) {
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
if (getLangOpts().CPlusPlus)
Cond = ParseCXXCondition(InitStmt, Loc, CK);
else {
ExprResult CondExpr = ParseExpression();
// If required, convert to a boolean value.
if (CondExpr.isInvalid())
Cond = Sema::ConditionError();
else
Cond = Actions.ActOnCondition(getCurScope(), Loc, CondExpr.get(), CK);
}
// 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 (Cond.isInvalid() && 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.
T.consumeClose();
if (LParenLoc != nullptr) {
*LParenLoc = T.getOpenLocation();
}
if (RParenLoc != nullptr) {
*RParenLoc = T.getCloseLocation();
}
// Check for extraneous ')'s to catch things like "if (foo())) {". We know
// that all callers are looking for a statement after the condition, so ")"
// isn't valid.
while (Tok.is(tok::r_paren)) {
Diag(Tok, diag::err_extraneous_rparen_in_condition)
<< FixItHint::CreateRemoval(Tok.getLocation());
ConsumeParen();
}
return false;
}
namespace {
enum MisleadingStatementKind { MSK_if, MSK_else, MSK_for, MSK_while };
struct MisleadingIndentationChecker {
Parser &P;
SourceLocation StmtLoc;
SourceLocation PrevLoc;
unsigned NumDirectives;
MisleadingStatementKind Kind;
bool ShouldSkip;
MisleadingIndentationChecker(Parser &P, MisleadingStatementKind K,
SourceLocation SL)
: P(P), StmtLoc(SL), PrevLoc(P.getCurToken().getLocation()),
NumDirectives(P.getPreprocessor().getNumDirectives()), Kind(K),
ShouldSkip(P.getCurToken().is(tok::l_brace)) {
if (!P.MisleadingIndentationElseLoc.isInvalid()) {
StmtLoc = P.MisleadingIndentationElseLoc;
P.MisleadingIndentationElseLoc = SourceLocation();
}
if (Kind == MSK_else && !ShouldSkip)
P.MisleadingIndentationElseLoc = SL;
}
/// Compute the column number will aligning tabs on TabStop (-ftabstop), this
/// gives the visual indentation of the SourceLocation.
static unsigned getVisualIndentation(SourceManager &SM, SourceLocation Loc) {
unsigned TabStop = SM.getDiagnostics().getDiagnosticOptions().TabStop;
unsigned ColNo = SM.getSpellingColumnNumber(Loc);
if (ColNo == 0 || TabStop == 1)
return ColNo;
std::pair<FileID, unsigned> FIDAndOffset = SM.getDecomposedLoc(Loc);
bool Invalid;
StringRef BufData = SM.getBufferData(FIDAndOffset.first, &Invalid);
if (Invalid)
return 0;
const char *EndPos = BufData.data() + FIDAndOffset.second;
// FileOffset are 0-based and Column numbers are 1-based
assert(FIDAndOffset.second + 1 >= ColNo &&
"Column number smaller than file offset?");
unsigned VisualColumn = 0; // Stored as 0-based column, here.
// Loop from beginning of line up to Loc's file position, counting columns,
// expanding tabs.
for (const char *CurPos = EndPos - (ColNo - 1); CurPos != EndPos;
++CurPos) {
if (*CurPos == '\t')
// Advance visual column to next tabstop.
VisualColumn += (TabStop - VisualColumn % TabStop);
else
VisualColumn++;
}
return VisualColumn + 1;
}
void Check() {
Token Tok = P.getCurToken();
if (P.getActions().getDiagnostics().isIgnored(
diag::warn_misleading_indentation, Tok.getLocation()) ||
ShouldSkip || NumDirectives != P.getPreprocessor().getNumDirectives() ||
Tok.isOneOf(tok::semi, tok::r_brace) || Tok.isAnnotation() ||
Tok.getLocation().isMacroID() || PrevLoc.isMacroID() ||
StmtLoc.isMacroID() ||
(Kind == MSK_else && P.MisleadingIndentationElseLoc.isInvalid())) {
P.MisleadingIndentationElseLoc = SourceLocation();
return;
}
if (Kind == MSK_else)
P.MisleadingIndentationElseLoc = SourceLocation();
SourceManager &SM = P.getPreprocessor().getSourceManager();
unsigned PrevColNum = getVisualIndentation(SM, PrevLoc);
unsigned CurColNum = getVisualIndentation(SM, Tok.getLocation());
unsigned StmtColNum = getVisualIndentation(SM, StmtLoc);
if (PrevColNum != 0 && CurColNum != 0 && StmtColNum != 0 &&
((PrevColNum > StmtColNum && PrevColNum == CurColNum) ||
!Tok.isAtStartOfLine()) &&
SM.getPresumedLineNumber(StmtLoc) !=
SM.getPresumedLineNumber(Tok.getLocation()) &&
(Tok.isNot(tok::identifier) ||
P.getPreprocessor().LookAhead(0).isNot(tok::colon))) {
P.Diag(Tok.getLocation(), diag::warn_misleading_indentation) << Kind;
P.Diag(StmtLoc, diag::note_previous_statement);
}
}
};
}
/// 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(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_if) && "Not an if stmt!");
SourceLocation IfLoc = ConsumeToken(); // eat the 'if'.
bool IsConstexpr = false;
if (Tok.is(tok::kw_constexpr)) {
Diag(Tok, getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_constexpr_if
: diag::ext_constexpr_if);
IsConstexpr = true;
ConsumeToken();
}
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "if";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXX = getLangOpts().C99 || getLangOpts().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.
StmtResult InitStmt;
Sema::ConditionResult Cond;
SourceLocation LParen;
SourceLocation RParen;
if (ParseParenExprOrCondition(&InitStmt, Cond, IfLoc,
IsConstexpr ? Sema::ConditionKind::ConstexprIf
: Sema::ConditionKind::Boolean,
&LParen, &RParen))
return StmtError();
llvm::Optional<bool> ConstexprCondition;
if (IsConstexpr)
ConstexprCondition = Cond.getKnownValue();
bool IsBracedThen = Tok.is(tok::l_brace);
// 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, IsBracedThen);
MisleadingIndentationChecker MIChecker(*this, MSK_if, IfLoc);
// Read the 'then' stmt.
SourceLocation ThenStmtLoc = Tok.getLocation();
SourceLocation InnerStatementTrailingElseLoc;
StmtResult ThenStmt;
{
EnterExpressionEvaluationContext PotentiallyDiscarded(
Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr,
Sema::ExpressionEvaluationContextRecord::EK_Other,
/*ShouldEnter=*/ConstexprCondition && !*ConstexprCondition);
ThenStmt = ParseStatement(&InnerStatementTrailingElseLoc);
}
if (Tok.isNot(tok::kw_else))
MIChecker.Check();
// 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)) {
if (TrailingElseLoc)
*TrailingElseLoc = Tok.getLocation();
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.is(tok::l_brace));
MisleadingIndentationChecker MIChecker(*this, MSK_else, ElseLoc);
EnterExpressionEvaluationContext PotentiallyDiscarded(
Actions, Sema::ExpressionEvaluationContext::DiscardedStatement, nullptr,
Sema::ExpressionEvaluationContextRecord::EK_Other,
/*ShouldEnter=*/ConstexprCondition && *ConstexprCondition);
ElseStmt = ParseStatement();
if (ElseStmt.isUsable())
MIChecker.Check();
// Pop the 'else' scope if needed.
InnerScope.Exit();
} else if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteAfterIf(getCurScope(), IsBracedThen);
cutOffParsing();
return StmtError();
} else if (InnerStatementTrailingElseLoc.isValid()) {
Diag(InnerStatementTrailingElseLoc, diag::warn_dangling_else);
}
IfScope.Exit();
// 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() == nullptr) ||
(ThenStmt.get() == nullptr && 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, IsConstexpr, LParen, InitStmt.get(), Cond,
RParen, ThenStmt.get(), ElseLoc, ElseStmt.get());
}
/// ParseSwitchStatement
/// switch-statement:
/// 'switch' '(' expression ')' statement
/// [C++] 'switch' '(' condition ')' statement
StmtResult Parser::ParseSwitchStatement(SourceLocation *TrailingElseLoc) {
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 = getLangOpts().C99 || getLangOpts().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::SwitchScope;
if (C99orCXX)
ScopeFlags |= Scope::DeclScope | Scope::ControlScope;
ParseScope SwitchScope(this, ScopeFlags);
// Parse the condition.
StmtResult InitStmt;
Sema::ConditionResult Cond;
SourceLocation LParen;
SourceLocation RParen;
if (ParseParenExprOrCondition(&InitStmt, Cond, SwitchLoc,
Sema::ConditionKind::Switch, &LParen, &RParen))
return StmtError();
StmtResult Switch = Actions.ActOnStartOfSwitchStmt(
SwitchLoc, LParen, InitStmt.get(), Cond, RParen);
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);
} else
SkipUntil(tok::semi);
return 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++.
//
getCurScope()->AddFlags(Scope::BreakScope);
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(tok::l_brace));
// We have incremented the mangling number for the SwitchScope and the
// InnerScope, which is one too many.
if (C99orCXX)
getCurScope()->decrementMSManglingNumber();
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
// Pop the scopes.
InnerScope.Exit();
SwitchScope.Exit();
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(SourceLocation *TrailingElseLoc) {
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 = getLangOpts().C99 || getLangOpts().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.
Sema::ConditionResult Cond;
SourceLocation LParen;
SourceLocation RParen;
if (ParseParenExprOrCondition(nullptr, Cond, WhileLoc,
Sema::ConditionKind::Boolean, &LParen, &RParen))
return StmtError();
// C99 6.8.5p5 - In C99, the body of the while 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.is(tok::l_brace));
MisleadingIndentationChecker MIChecker(*this, MSK_while, WhileLoc);
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
if (Body.isUsable())
MIChecker.Check();
// Pop the body scope if needed.
InnerScope.Exit();
WhileScope.Exit();
if (Cond.isInvalid() || Body.isInvalid())
return StmtError();
return Actions.ActOnWhileStmt(WhileLoc, LParen, Cond, RParen, 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() {
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 (getLangOpts().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 do 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.
//
bool C99orCXX = getLangOpts().C99 || getLangOpts().CPlusPlus;
ParseScope InnerScope(this, Scope::DeclScope, C99orCXX, Tok.is(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, StopBeforeMatch);
}
return StmtError();
}
SourceLocation WhileLoc = ConsumeToken();
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "do/while";
SkipUntil(tok::semi, StopBeforeMatch);
return StmtError();
}
// Parse the parenthesized expression.
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
// A do-while expression is not a condition, so can't have attributes.
DiagnoseAndSkipCXX11Attributes();
ExprResult Cond = ParseExpression();
// Correct the typos in condition before closing the scope.
if (Cond.isUsable())
Cond = Actions.CorrectDelayedTyposInExpr(Cond);
T.consumeClose();
DoScope.Exit();
if (Cond.isInvalid() || Body.isInvalid())
return StmtError();
return Actions.ActOnDoStmt(DoLoc, Body.get(), WhileLoc, T.getOpenLocation(),
Cond.get(), T.getCloseLocation());
}
bool Parser::isForRangeIdentifier() {
assert(Tok.is(tok::identifier));
const Token &Next = NextToken();
if (Next.is(tok::colon))
return true;
if (Next.isOneOf(tok::l_square, tok::kw_alignas)) {
TentativeParsingAction PA(*this);
ConsumeToken();
SkipCXX11Attributes();
bool Result = Tok.is(tok::colon);
PA.Revert();
return Result;
}
return false;
}
/// 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
/// [C++0x] 'for'
/// 'co_await'[opt] [Coroutines]
/// '(' for-range-declaration ':' for-range-initializer ')'
/// statement
/// [OBJC2] 'for' '(' declaration 'in' expr ')' statement
/// [OBJC2] 'for' '(' expr 'in' expr ')' statement
///
/// [C++] for-init-statement:
/// [C++] expression-statement
/// [C++] simple-declaration
///
/// [C++0x] for-range-declaration:
/// [C++0x] attribute-specifier-seq[opt] type-specifier-seq declarator
/// [C++0x] for-range-initializer:
/// [C++0x] expression
/// [C++0x] braced-init-list [TODO]
StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
assert(Tok.is(tok::kw_for) && "Not a for stmt!");
SourceLocation ForLoc = ConsumeToken(); // eat the 'for'.
SourceLocation CoawaitLoc;
if (Tok.is(tok::kw_co_await))
CoawaitLoc = ConsumeToken();
if (Tok.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after) << "for";
SkipUntil(tok::semi);
return StmtError();
}
bool C99orCXXorObjC = getLangOpts().C99 || getLangOpts().CPlusPlus ||
getLangOpts().ObjC;
// 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 = 0;
if (C99orCXXorObjC)
ScopeFlags = Scope::DeclScope | Scope::ControlScope;
ParseScope ForScope(this, ScopeFlags);
BalancedDelimiterTracker T(*this, tok::l_paren);
T.consumeOpen();
ExprResult Value;
bool ForEach = false;
StmtResult FirstPart;
Sema::ConditionResult SecondPart;
ExprResult Collection;
ForRangeInfo ForRangeInfo;
FullExprArg ThirdPart(Actions);
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteOrdinaryName(getCurScope(),
C99orCXXorObjC? Sema::PCC_ForInit
: Sema::PCC_Expression);
cutOffParsing();
return StmtError();
}
ParsedAttributesWithRange attrs(AttrFactory);
MaybeParseCXX11Attributes(attrs);
SourceLocation EmptyInitStmtSemiLoc;
// Parse the first part of the for specifier.
if (Tok.is(tok::semi)) { // for (;
ProhibitAttributes(attrs);
// no first part, eat the ';'.
SourceLocation SemiLoc = Tok.getLocation();
if (!Tok.hasLeadingEmptyMacro() && !SemiLoc.isMacroID())
EmptyInitStmtSemiLoc = SemiLoc;
ConsumeToken();
} else if (getLangOpts().CPlusPlus && Tok.is(tok::identifier) &&
isForRangeIdentifier()) {
ProhibitAttributes(attrs);
IdentifierInfo *Name = Tok.getIdentifierInfo();
SourceLocation Loc = ConsumeToken();
MaybeParseCXX11Attributes(attrs);
ForRangeInfo.ColonLoc = ConsumeToken();
if (Tok.is(tok::l_brace))
ForRangeInfo.RangeExpr = ParseBraceInitializer();
else
ForRangeInfo.RangeExpr = ParseExpression();
Diag(Loc, diag::err_for_range_identifier)
<< ((getLangOpts().CPlusPlus11 && !getLangOpts().CPlusPlus17)
? FixItHint::CreateInsertion(Loc, "auto &&")
: FixItHint());
ForRangeInfo.LoopVar = Actions.ActOnCXXForRangeIdentifier(
getCurScope(), Loc, Name, attrs, attrs.Range.getEnd());
} else if (isForInitDeclaration()) { // for (int X = 4;
ParenBraceBracketBalancer BalancerRAIIObj(*this);
// 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);
Diag(Tok, diag::warn_gcc_variable_decl_in_for_loop);
}
// In C++0x, "for (T NS:a" might not be a typo for ::
bool MightBeForRangeStmt = getLangOpts().CPlusPlus;
ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
DeclGroupPtrTy DG = ParseSimpleDeclaration(
DeclaratorContext::ForContext, DeclEnd, attrs, false,
MightBeForRangeStmt ? &ForRangeInfo : nullptr);
FirstPart = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
if (ForRangeInfo.ParsedForRangeDecl()) {
Diag(ForRangeInfo.ColonLoc, getLangOpts().CPlusPlus11 ?
diag::warn_cxx98_compat_for_range : diag::ext_for_range);
ForRangeInfo.LoopVar = FirstPart;
FirstPart = StmtResult();
} else 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);
cutOffParsing();
return StmtError();
}
Collection = ParseExpression();
} else {
Diag(Tok, diag::err_expected_semi_for);
}
} else {
ProhibitAttributes(attrs);
Value = Actions.CorrectDelayedTyposInExpr(ParseExpression());
ForEach = isTokIdentifier_in();
// Turn the expression into a stmt.
if (!Value.isInvalid()) {
if (ForEach)
FirstPart = Actions.ActOnForEachLValueExpr(Value.get());
else {
// We already know this is not an init-statement within a for loop, so
// if we are parsing a C++11 range-based for loop, we should treat this
// expression statement as being a discarded value expression because
// we will err below. This way we do not warn on an unused expression
// that was an error in the first place, like with: for (expr : expr);
bool IsRangeBasedFor =
getLangOpts().CPlusPlus11 && !ForEach && Tok.is(tok::colon);
FirstPart = Actions.ActOnExprStmt(Value, !IsRangeBasedFor);
}
}
if (Tok.is(tok::semi)) {
ConsumeToken();
} else if (ForEach) {
ConsumeToken(); // consume 'in'
if (Tok.is(tok::code_completion)) {
Actions.CodeCompleteObjCForCollection(getCurScope(), nullptr);
cutOffParsing();
return StmtError();
}
Collection = ParseExpression();
} else if (getLangOpts().CPlusPlus11 && Tok.is(tok::colon) && FirstPart.get()) {
// User tried to write the reasonable, but ill-formed, for-range-statement
// for (expr : expr) { ... }
Diag(Tok, diag::err_for_range_expected_decl)
<< FirstPart.get()->getSourceRange();
SkipUntil(tok::r_paren, StopBeforeMatch);
SecondPart = Sema::ConditionError();
} 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, StopAtSemi | StopBeforeMatch);
if (Tok.is(tok::semi))
ConsumeToken();
}
}
}
// Parse the second part of the for specifier.
getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope);
if (!ForEach && !ForRangeInfo.ParsedForRangeDecl() &&
!SecondPart.isInvalid()) {
// 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 {
if (getLangOpts().CPlusPlus) {
// C++2a: We've parsed an init-statement; we might have a
// for-range-declaration next.
bool MightBeForRangeStmt = !ForRangeInfo.ParsedForRangeDecl();
ColonProtectionRAIIObject ColonProtection(*this, MightBeForRangeStmt);
SecondPart =
ParseCXXCondition(nullptr, ForLoc, Sema::ConditionKind::Boolean,
MightBeForRangeStmt ? &ForRangeInfo : nullptr);
if (ForRangeInfo.ParsedForRangeDecl()) {
Diag(FirstPart.get() ? FirstPart.get()->getBeginLoc()
: ForRangeInfo.ColonLoc,
getLangOpts().CPlusPlus20
? diag::warn_cxx17_compat_for_range_init_stmt
: diag::ext_for_range_init_stmt)
<< (FirstPart.get() ? FirstPart.get()->getSourceRange()
: SourceRange());
if (EmptyInitStmtSemiLoc.isValid()) {
Diag(EmptyInitStmtSemiLoc, diag::warn_empty_init_statement)
<< /*for-loop*/ 2
<< FixItHint::CreateRemoval(EmptyInitStmtSemiLoc);
}
}
} else {
ExprResult SecondExpr = ParseExpression();
if (SecondExpr.isInvalid())
SecondPart = Sema::ConditionError();
else
SecondPart =
Actions.ActOnCondition(getCurScope(), ForLoc, SecondExpr.get(),
Sema::ConditionKind::Boolean);
}
}
}
// Parse the third part of the for statement.
if (!ForEach && !ForRangeInfo.ParsedForRangeDecl()) {
if (Tok.isNot(tok::semi)) {
if (!SecondPart.isInvalid())
Diag(Tok, diag::err_expected_semi_for);
else
// Skip until semicolon or rparen, don't consume it.
SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
}
if (Tok.is(tok::semi)) {
ConsumeToken();
}
if (Tok.isNot(tok::r_paren)) { // for (...;...;)
ExprResult Third = ParseExpression();
// FIXME: The C++11 standard doesn't actually say that this is a
// discarded-value expression, but it clearly should be.
ThirdPart = Actions.MakeFullDiscardedValueExpr(Third.get());
}
}
// Match the ')'.
T.consumeClose();
// C++ Coroutines [stmt.iter]:
// 'co_await' can only be used for a range-based for statement.
if (CoawaitLoc.isValid() && !ForRangeInfo.ParsedForRangeDecl()) {
Diag(CoawaitLoc, diag::err_for_co_await_not_range_for);
CoawaitLoc = SourceLocation();
}
// We need to perform most of the semantic analysis for a C++0x for-range
// statememt before parsing the body, in order to be able to deduce the type
// of an auto-typed loop variable.
StmtResult ForRangeStmt;
StmtResult ForEachStmt;
if (ForRangeInfo.ParsedForRangeDecl()) {
ExprResult CorrectedRange =
Actions.CorrectDelayedTyposInExpr(ForRangeInfo.RangeExpr.get());
ForRangeStmt = Actions.ActOnCXXForRangeStmt(
getCurScope(), ForLoc, CoawaitLoc, FirstPart.get(),
ForRangeInfo.LoopVar.get(), ForRangeInfo.ColonLoc, CorrectedRange.get(),
T.getCloseLocation(), Sema::BFRK_Build);
// Similarly, we need to do the semantic analysis for a for-range
// statement immediately in order to close over temporaries correctly.
} else if (ForEach) {
ForEachStmt = Actions.ActOnObjCForCollectionStmt(ForLoc,
FirstPart.get(),
Collection.get(),
T.getCloseLocation());
} else {
// In OpenMP loop region loop control variable must be captured and be
// private. Perform analysis of first part (if any).
if (getLangOpts().OpenMP && FirstPart.isUsable()) {
Actions.ActOnOpenMPLoopInitialization(ForLoc, FirstPart.get());
}
}
// C99 6.8.5p5 - In C99, the body of the for 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.is(tok::l_brace));
// The body of the for loop has the same local mangling number as the
// for-init-statement.
// It will only be incremented if the body contains other things that would
// normally increment the mangling number (like a compound statement).
if (C99orCXXorObjC)
getCurScope()->decrementMSManglingNumber();
MisleadingIndentationChecker MIChecker(*this, MSK_for, ForLoc);
// Read the body statement.
StmtResult Body(ParseStatement(TrailingElseLoc));
if (Body.isUsable())
MIChecker.Check();
// Pop the body scope if needed.
InnerScope.Exit();
// Leave the for-scope.
ForScope.Exit();
if (Body.isInvalid())
return StmtError();
if (ForEach)
return Actions.FinishObjCForCollectionStmt(ForEachStmt.get(),
Body.get());
if (ForRangeInfo.ParsedForRangeDecl())
return Actions.FinishCXXForRangeStmt(ForRangeStmt.get(), Body.get());
return Actions.ActOnForStmt(ForLoc, T.getOpenLocation(), FirstPart.get(),
SecondPart, ThirdPart, T.getCloseLocation(),
Body.get());
}
/// ParseGotoStatement
/// jump-statement:
/// 'goto' identifier ';'
/// [GNU] 'goto' '*' expression ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseGotoStatement() {
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, StopBeforeMatch);
return StmtError();
}
Res = Actions.ActOnIndirectGotoStmt(GotoLoc, StarLoc, R.get());
} else {
Diag(Tok, diag::err_expected) << tok::identifier;
return StmtError();
}
return Res;
}
/// ParseContinueStatement
/// jump-statement:
/// 'continue' ';'
///
/// Note: this lets the caller parse the end ';'.
///
StmtResult Parser::ParseContinueStatement() {
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() {
SourceLocation BreakLoc = ConsumeToken(); // eat the 'break'.
return Actions.ActOnBreakStmt(BreakLoc, getCurScope());
}
/// ParseReturnStatement
/// jump-statement:
/// 'return' expression[opt] ';'
/// 'return' braced-init-list ';'
/// 'co_return' expression[opt] ';'
/// 'co_return' braced-init-list ';'
StmtResult Parser::ParseReturnStatement() {
assert((Tok.is(tok::kw_return) || Tok.is(tok::kw_co_return)) &&
"Not a return stmt!");
bool IsCoreturn = Tok.is(tok::kw_co_return);
SourceLocation ReturnLoc = ConsumeToken(); // eat the 'return'.
ExprResult R;
if (Tok.isNot(tok::semi)) {
if (!IsCoreturn)
PreferredType.enterReturn(Actions, Tok.getLocation());
// FIXME: Code completion for co_return.
if (Tok.is(tok::code_completion) && !IsCoreturn) {
Actions.CodeCompleteExpression(getCurScope(),
PreferredType.get(Tok.getLocation()));
cutOffParsing();
return StmtError();
}
if (Tok.is(tok::l_brace) && getLangOpts().CPlusPlus) {
R = ParseInitializer();
if (R.isUsable())
Diag(R.get()->getBeginLoc(),
getLangOpts().CPlusPlus11
? diag::warn_cxx98_compat_generalized_initializer_lists
: diag::ext_generalized_initializer_lists)
<< R.get()->getSourceRange();
} else
R = ParseExpression();
if (R.isInvalid()) {
SkipUntil(tok::r_brace, StopAtSemi | StopBeforeMatch);
return StmtError();
}
}
if (IsCoreturn)
return Actions.ActOnCoreturnStmt(getCurScope(), ReturnLoc, R.get());
return Actions.ActOnReturnStmt(ReturnLoc, R.get(), getCurScope());
}
StmtResult Parser::ParsePragmaLoopHint(StmtVector &Stmts,
ParsedStmtContext StmtCtx,
SourceLocation *TrailingElseLoc,
ParsedAttributesWithRange &Attrs) {
// Create temporary attribute list.
ParsedAttributesWithRange TempAttrs(AttrFactory);
SourceLocation StartLoc = Tok.getLocation();
// Get loop hints and consume annotated token.
while (Tok.is(tok::annot_pragma_loop_hint)) {
LoopHint Hint;
if (!HandlePragmaLoopHint(Hint))
continue;
ArgsUnion ArgHints[] = {Hint.PragmaNameLoc, Hint.OptionLoc, Hint.StateLoc,
ArgsUnion(Hint.ValueExpr)};
TempAttrs.addNew(Hint.PragmaNameLoc->Ident, Hint.Range, nullptr,
Hint.PragmaNameLoc->Loc, ArgHints, 4,
ParsedAttr::AS_Pragma);
}
// Get the next statement.
MaybeParseCXX11Attributes(Attrs);
StmtResult S = ParseStatementOrDeclarationAfterAttributes(
Stmts, StmtCtx, TrailingElseLoc, Attrs);
Attrs.takeAllFrom(TempAttrs);
// Start of attribute range may already be set for some invalid input.
// See PR46336.
if (Attrs.Range.getBegin().isInvalid())
Attrs.Range.setBegin(StartLoc);
return S;
}
Decl *Parser::ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope) {
assert(Tok.is(tok::l_brace));
SourceLocation LBraceLoc = Tok.getLocation();
PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, LBraceLoc,
"parsing function body");
// Save and reset current vtordisp stack if we have entered a C++ method body.
bool IsCXXMethod =
getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
Sema::PragmaStackSentinelRAII
PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
// 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()) {
Sema::CompoundScopeRAII CompoundScope(Actions);
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
}
BodyScope.Exit();
return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
}
/// ParseFunctionTryBlock - Parse a C++ function-try-block.
///
/// function-try-block:
/// 'try' ctor-initializer[opt] compound-statement handler-seq
///
Decl *Parser::ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope) {
assert(Tok.is(tok::kw_try) && "Expected 'try'");
SourceLocation TryLoc = ConsumeToken();
PrettyDeclStackTraceEntry CrashInfo(Actions.Context, Decl, TryLoc,
"parsing function try block");
// Constructor initializer list?
if (Tok.is(tok::colon))
ParseConstructorInitializer(Decl);
else
Actions.ActOnDefaultCtorInitializers(Decl);
// Save and reset current vtordisp stack if we have entered a C++ method body.
bool IsCXXMethod =
getLangOpts().CPlusPlus && Decl && isa<CXXMethodDecl>(Decl);
Sema::PragmaStackSentinelRAII
PragmaStackSentinel(Actions, "InternalPragmaState", IsCXXMethod);
SourceLocation LBraceLoc = Tok.getLocation();
StmtResult FnBody(ParseCXXTryBlockCommon(TryLoc, /*FnTry*/true));
// If we failed to parse the try-catch, we just give the function an empty
// compound statement as the body.
if (FnBody.isInvalid()) {
Sema::CompoundScopeRAII CompoundScope(Actions);
FnBody = Actions.ActOnCompoundStmt(LBraceLoc, LBraceLoc, None, false);
}
BodyScope.Exit();
return Actions.ActOnFinishFunctionBody(Decl, FnBody.get());
}
bool Parser::trySkippingFunctionBody() {
assert(SkipFunctionBodies &&
"Should only be called when SkipFunctionBodies is enabled");
if (!PP.isCodeCompletionEnabled()) {
SkipFunctionBody();
return true;
}
// We're in code-completion mode. Skip parsing for all function bodies unless
// the body contains the code-completion point.
TentativeParsingAction PA(*this);
bool IsTryCatch = Tok.is(tok::kw_try);
CachedTokens Toks;
bool ErrorInPrologue = ConsumeAndStoreFunctionPrologue(Toks);
if (llvm::any_of(Toks, [](const Token &Tok) {
return Tok.is(tok::code_completion);
})) {
PA.Revert();
return false;
}
if (ErrorInPrologue) {
PA.Commit();
SkipMalformedDecl();
return true;
}
if (!SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
PA.Revert();
return false;
}
while (IsTryCatch && Tok.is(tok::kw_catch)) {
if (!SkipUntil(tok::l_brace, StopAtCodeCompletion) ||
!SkipUntil(tok::r_brace, StopAtCodeCompletion)) {
PA.Revert();
return false;
}
}
PA.Commit();
return true;
}
/// ParseCXXTryBlock - Parse a C++ try-block.
///
/// try-block:
/// 'try' compound-statement handler-seq
///
StmtResult Parser::ParseCXXTryBlock() {
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]
///
/// [Borland] try-block:
/// 'try' compound-statement seh-except-block
/// 'try' compound-statement seh-finally-block
///
StmtResult Parser::ParseCXXTryBlockCommon(SourceLocation TryLoc, bool FnTry) {
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
StmtResult TryBlock(ParseCompoundStatement(
/*isStmtExpr=*/false, Scope::DeclScope | Scope::TryScope |
Scope::CompoundStmtScope |
(FnTry ? Scope::FnTryCatchScope : 0)));
if (TryBlock.isInvalid())
return TryBlock;
// Borland allows SEH-handlers with 'try'
if ((Tok.is(tok::identifier) &&
Tok.getIdentifierInfo() == getSEHExceptKeyword()) ||
Tok.is(tok::kw___finally)) {
// TODO: Factor into common return ParseSEHHandlerCommon(...)
StmtResult Handler;
if(Tok.getIdentifierInfo() == getSEHExceptKeyword()) {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHExceptBlock(Loc);
}
else {
SourceLocation Loc = ConsumeToken();
Handler = ParseSEHFinallyBlock(Loc);
}
if(Handler.isInvalid())
return Handler;
return Actions.ActOnSEHTryBlock(true /* IsCXXTry */,
TryLoc,
TryBlock.get(),
Handler.get());
}
else {
StmtVector Handlers;
// C++11 attributes can't appear here, despite this context seeming
// statement-like.
DiagnoseAndSkipCXX11Attributes();
if (Tok.isNot(tok::kw_catch))
return StmtError(Diag(Tok, diag::err_expected_catch));
while (Tok.is(tok::kw_catch)) {
StmtResult Handler(ParseCXXCatchBlock(FnTry));
if (!Handler.isInvalid())
Handlers.push_back(Handler.get());
}
// 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.get(), Handlers);
}
}
/// ParseCXXCatchBlock - Parse a C++ catch block, called handler in the standard
///
/// handler:
/// 'catch' '(' exception-declaration ')' compound-statement
///
/// exception-declaration:
/// attribute-specifier-seq[opt] type-specifier-seq declarator
/// attribute-specifier-seq[opt] type-specifier-seq abstract-declarator[opt]
/// '...'
///
StmtResult Parser::ParseCXXCatchBlock(bool FnCatch) {
assert(Tok.is(tok::kw_catch) && "Expected 'catch'");
SourceLocation CatchLoc = ConsumeToken();
BalancedDelimiterTracker T(*this, tok::l_paren);
if (T.expectAndConsume())
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 |
Scope::CatchScope |
(FnCatch ? Scope::FnTryCatchScope : 0));
// exception-declaration is equivalent to '...' or a parameter-declaration
// without default arguments.
Decl *ExceptionDecl = nullptr;
if (Tok.isNot(tok::ellipsis)) {
ParsedAttributesWithRange Attributes(AttrFactory);
MaybeParseCXX11Attributes(Attributes);
DeclSpec DS(AttrFactory);
DS.takeAttributesFrom(Attributes);
if (ParseCXXTypeSpecifierSeq(DS))
return StmtError();
Declarator ExDecl(DS, DeclaratorContext::CXXCatchContext);
ParseDeclarator(ExDecl);
ExceptionDecl = Actions.ActOnExceptionDeclarator(getCurScope(), ExDecl);
} else
ConsumeToken();
T.consumeClose();
if (T.getCloseLocation().isInvalid())
return StmtError();
if (Tok.isNot(tok::l_brace))
return StmtError(Diag(Tok, diag::err_expected) << tok::l_brace);
// FIXME: Possible draft standard bug: attribute-specifier should be allowed?
StmtResult Block(ParseCompoundStatement());
if (Block.isInvalid())
return Block;
return Actions.ActOnCXXCatchBlock(CatchLoc, ExceptionDecl, Block.get());
}
void Parser::ParseMicrosoftIfExistsStatement(StmtVector &Stmts) {
IfExistsCondition Result;
if (ParseMicrosoftIfExistsCondition(Result))
return;
// Handle dependent statements by parsing the braces as a compound statement.
// This is not the same behavior as Visual C++, which don't treat this as a
// compound statement, but for Clang's type checking we can't have anything
// inside these braces escaping to the surrounding code.
if (Result.Behavior == IEB_Dependent) {
if (!Tok.is(tok::l_brace)) {
Diag(Tok, diag::err_expected) << tok::l_brace;
return;
}
StmtResult Compound = ParseCompoundStatement();
if (Compound.isInvalid())
return;
StmtResult DepResult = Actions.ActOnMSDependentExistsStmt(Result.KeywordLoc,
Result.IsIfExists,
Result.SS,
Result.Name,
Compound.get());
if (DepResult.isUsable())
Stmts.push_back(DepResult.get());
return;
}
BalancedDelimiterTracker Braces(*this, tok::l_brace);
if (Braces.consumeOpen()) {
Diag(Tok, diag::err_expected) << tok::l_brace;
return;
}
switch (Result.Behavior) {
case IEB_Parse:
// Parse the statements below.
break;
case IEB_Dependent:
llvm_unreachable("Dependent case handled above");
case IEB_Skip:
Braces.skipToEnd();
return;
}
// Condition is true, parse the statements.
while (Tok.isNot(tok::r_brace)) {
StmtResult R =
ParseStatementOrDeclaration(Stmts, ParsedStmtContext::Compound);
if (R.isUsable())
Stmts.push_back(R.get());
}
Braces.consumeClose();
}
bool Parser::ParseOpenCLUnrollHintAttribute(ParsedAttributes &Attrs) {
MaybeParseGNUAttributes(Attrs);
if (Attrs.empty())
return true;
if (Attrs.begin()->getKind() != ParsedAttr::AT_OpenCLUnrollHint)
return true;
if (!(Tok.is(tok::kw_for) || Tok.is(tok::kw_while) || Tok.is(tok::kw_do))) {
Diag(Tok, diag::err_opencl_unroll_hint_on_non_loop);
return false;
}
return true;
}
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