diff options
Diffstat (limited to 'lib/Sema/SemaStmt.cpp')
| -rw-r--r-- | lib/Sema/SemaStmt.cpp | 270 |
1 files changed, 158 insertions, 112 deletions
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp index bb025a4fb3..8367c1a220 100644 --- a/lib/Sema/SemaStmt.cpp +++ b/lib/Sema/SemaStmt.cpp @@ -1549,25 +1549,6 @@ Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, ForLoc, RParenLoc)); } -namespace { - -enum BeginEndFunction { - BEF_begin, - BEF_end -}; - -/// Build a variable declaration for a for-range statement. -static VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, - QualType Type, const char *Name) { - DeclContext *DC = SemaRef.CurContext; - IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); - TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); - VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, - TInfo, SC_Auto, SC_None); - Decl->setImplicit(); - return Decl; -} - /// Finish building a variable declaration for a for-range statement. /// \return true if an error occurs. static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, @@ -1600,12 +1581,14 @@ static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, return false; } +namespace { + /// Produce a note indicating which begin/end function was implicitly called -/// by a C++0x for-range statement. This is often not obvious from the code, +/// by a C++11 for-range statement. This is often not obvious from the code, /// nor from the diagnostics produced when analysing the implicit expressions /// required in a for-range statement. void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, - BeginEndFunction BEF) { + Sema::BeginEndFunction BEF) { CallExpr *CE = dyn_cast<CallExpr>(E); if (!CE) return; @@ -1626,56 +1609,16 @@ void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, << BEF << IsTemplate << Description << E->getType(); } -/// Build a call to 'begin' or 'end' for a C++0x for-range statement. If the -/// given LookupResult is non-empty, it is assumed to describe a member which -/// will be invoked. Otherwise, the function will be found via argument -/// dependent lookup. -static ExprResult BuildForRangeBeginEndCall(Sema &SemaRef, Scope *S, - SourceLocation Loc, - VarDecl *Decl, - BeginEndFunction BEF, - const DeclarationNameInfo &NameInfo, - LookupResult &MemberLookup, - Expr *Range) { - ExprResult CallExpr; - if (!MemberLookup.empty()) { - ExprResult MemberRef = - SemaRef.BuildMemberReferenceExpr(Range, Range->getType(), Loc, - /*IsPtr=*/false, CXXScopeSpec(), - /*TemplateKWLoc=*/SourceLocation(), - /*FirstQualifierInScope=*/0, - MemberLookup, - /*TemplateArgs=*/0); - if (MemberRef.isInvalid()) - return ExprError(); - CallExpr = SemaRef.ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), - Loc, 0); - if (CallExpr.isInvalid()) - return ExprError(); - } else { - UnresolvedSet<0> FoundNames; - // C++0x [stmt.ranged]p1: For the purposes of this name lookup, namespace - // std is an associated namespace. - UnresolvedLookupExpr *Fn = - UnresolvedLookupExpr::Create(SemaRef.Context, /*NamingClass=*/0, - NestedNameSpecifierLoc(), NameInfo, - /*NeedsADL=*/true, /*Overloaded=*/false, - FoundNames.begin(), FoundNames.end(), - /*LookInStdNamespace=*/true); - CallExpr = SemaRef.BuildOverloadedCallExpr(S, Fn, Fn, Loc, &Range, 1, Loc, - 0, /*AllowTypoCorrection=*/false); - if (CallExpr.isInvalid()) { - SemaRef.Diag(Range->getLocStart(), diag::note_for_range_type) - << Range->getType(); - return ExprError(); - } - } - if (FinishForRangeVarDecl(SemaRef, Decl, CallExpr.get(), Loc, - diag::err_for_range_iter_deduction_failure)) { - NoteForRangeBeginEndFunction(SemaRef, CallExpr.get(), BEF); - return ExprError(); - } - return CallExpr; +/// Build a variable declaration for a for-range statement. +VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, + QualType Type, const char *Name) { + DeclContext *DC = SemaRef.CurContext; + IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); + TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); + VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, + TInfo, SC_Auto, SC_None); + Decl->setImplicit(); + return Decl; } } @@ -1706,7 +1649,7 @@ static bool ObjCEnumerationCollection(Expr *Collection) { StmtResult Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, Stmt *First, SourceLocation ColonLoc, Expr *Range, - SourceLocation RParenLoc) { + SourceLocation RParenLoc, bool ShouldTryDeref) { if (!First || !Range) return StmtError(); @@ -1744,7 +1687,111 @@ Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, - RParenLoc); + RParenLoc, ShouldTryDeref); +} + +/// \brief Create the initialization, compare, and increment steps for +/// the range-based for loop expression. +/// This function does not handle array-based for loops, +/// which are created in Sema::BuildCXXForRangeStmt. +/// +/// \returns a ForRangeStatus indicating success or what kind of error occurred. +/// BeginExpr and EndExpr are set and FRS_Success is returned on success; +/// CandidateSet and BEF are set and some non-success value is returned on +/// failure. +static Sema::ForRangeStatus BuildNonArrayForRange(Sema &SemaRef, Scope *S, + Expr *BeginRange, Expr *EndRange, + QualType RangeType, + VarDecl *BeginVar, + VarDecl *EndVar, + SourceLocation ColonLoc, + OverloadCandidateSet *CandidateSet, + ExprResult *BeginExpr, + ExprResult *EndExpr, + Sema::BeginEndFunction *BEF) { + DeclarationNameInfo BeginNameInfo( + &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc); + DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"), + ColonLoc); + + LookupResult BeginMemberLookup(SemaRef, BeginNameInfo, + Sema::LookupMemberName); + LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName); + + if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { + // - if _RangeT is a class type, the unqualified-ids begin and end are + // looked up in the scope of class _RangeT as if by class member access + // lookup (3.4.5), and if either (or both) finds at least one + // declaration, begin-expr and end-expr are __range.begin() and + // __range.end(), respectively; + SemaRef.LookupQualifiedName(BeginMemberLookup, D); + SemaRef.LookupQualifiedName(EndMemberLookup, D); + + if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { + SourceLocation RangeLoc = BeginVar->getLocation(); + *BEF = BeginMemberLookup.empty() ? Sema::BEF_end : Sema::BEF_begin; + + SemaRef.Diag(RangeLoc, diag::err_for_range_member_begin_end_mismatch) + << RangeLoc << BeginRange->getType() << *BEF; + return Sema::FRS_DiagnosticIssued; + } + } else { + // - otherwise, begin-expr and end-expr are begin(__range) and + // end(__range), respectively, where begin and end are looked up with + // argument-dependent lookup (3.4.2). For the purposes of this name + // lookup, namespace std is an associated namespace. + + } + + *BEF = Sema::BEF_begin; + Sema::ForRangeStatus RangeStatus = + SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, BeginVar, + Sema::BEF_begin, BeginNameInfo, + BeginMemberLookup, CandidateSet, + BeginRange, BeginExpr); + + if (RangeStatus != Sema::FRS_Success) + return RangeStatus; + if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + + *BEF = Sema::BEF_end; + RangeStatus = + SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, EndVar, + Sema::BEF_end, EndNameInfo, + EndMemberLookup, CandidateSet, + EndRange, EndExpr); + if (RangeStatus != Sema::FRS_Success) + return RangeStatus; + if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + return Sema::FRS_Success; +} + +/// Speculatively attempt to dereference an invalid range expression. +/// This function will not emit diagnostics, but returns StmtError if +/// an error occurs. +static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S, + SourceLocation ForLoc, + Stmt *LoopVarDecl, + SourceLocation ColonLoc, + Expr *Range, + SourceLocation RangeLoc, + SourceLocation RParenLoc) { + Sema::SFINAETrap Trap(SemaRef); + ExprResult AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range); + StmtResult SR = + SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc, + AdjustedRange.get(), RParenLoc, false); + if (Trap.hasErrorOccurred()) + return StmtError(); + return SR; } /// BuildCXXForRangeStmt - Build or instantiate a C++0x for-range statement. @@ -1752,7 +1799,7 @@ StmtResult Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, Expr *Inc, Stmt *LoopVarDecl, - SourceLocation RParenLoc) { + SourceLocation RParenLoc, bool ShouldTryDeref) { Scope *S = getCurScope(); DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); @@ -1838,50 +1885,49 @@ Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, return StmtError(); } } else { - DeclarationNameInfo BeginNameInfo(&PP.getIdentifierTable().get("begin"), - ColonLoc); - DeclarationNameInfo EndNameInfo(&PP.getIdentifierTable().get("end"), - ColonLoc); - - LookupResult BeginMemberLookup(*this, BeginNameInfo, LookupMemberName); - LookupResult EndMemberLookup(*this, EndNameInfo, LookupMemberName); - - if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { - // - if _RangeT is a class type, the unqualified-ids begin and end are - // looked up in the scope of class _RangeT as if by class member access - // lookup (3.4.5), and if either (or both) finds at least one - // declaration, begin-expr and end-expr are __range.begin() and - // __range.end(), respectively; - LookupQualifiedName(BeginMemberLookup, D); - LookupQualifiedName(EndMemberLookup, D); - - if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { - Diag(ColonLoc, diag::err_for_range_member_begin_end_mismatch) - << RangeType << BeginMemberLookup.empty(); - return StmtError(); + OverloadCandidateSet CandidateSet(RangeLoc); + Sema::BeginEndFunction BEFFailure; + ForRangeStatus RangeStatus = + BuildNonArrayForRange(*this, S, BeginRangeRef.get(), + EndRangeRef.get(), RangeType, + BeginVar, EndVar, ColonLoc, &CandidateSet, + &BeginExpr, &EndExpr, &BEFFailure); + + // If building the range failed, try dereferencing the range expression + // unless a diagnostic was issued or the end function is problematic. + if (ShouldTryDeref && RangeStatus == FRS_NoViableFunction && + BEFFailure == BEF_begin) { + StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc, + LoopVarDecl, ColonLoc, + Range, RangeLoc, + RParenLoc); + if (!SR.isInvalid()) { + // The attempt to dereference would succeed; return the result of + // recovery. + Diag(RangeLoc, diag::err_for_range_dereference) + << RangeLoc << RangeType + << FixItHint::CreateInsertion(RangeLoc, "*"); + return SR; } - } else { - // - otherwise, begin-expr and end-expr are begin(__range) and - // end(__range), respectively, where begin and end are looked up with - // argument-dependent lookup (3.4.2). For the purposes of this name - // lookup, namespace std is an associated namespace. } - BeginExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, BeginVar, - BEF_begin, BeginNameInfo, - BeginMemberLookup, - BeginRangeRef.get()); - if (BeginExpr.isInvalid()) - return StmtError(); - - EndExpr = BuildForRangeBeginEndCall(*this, S, ColonLoc, EndVar, - BEF_end, EndNameInfo, - EndMemberLookup, EndRangeRef.get()); - if (EndExpr.isInvalid()) + // Otherwise, emit diagnostics if we haven't already. + if (RangeStatus == FRS_NoViableFunction) { + Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get(); + Diag(Range->getLocStart(), diag::err_for_range_invalid) + << RangeLoc << Range->getType() << BEFFailure; + CandidateSet.NoteCandidates(*this, OCD_AllCandidates, + llvm::makeArrayRef(&Range, /*NumArgs=*/1)); + } + // Return an error if no fix was discovered. + if (RangeStatus != FRS_Success) return StmtError(); } - // C++0x [decl.spec.auto]p6: BeginType and EndType must be the same. + assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() && + "invalid range expression in for loop"); + + // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same. QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); if (!Context.hasSameType(BeginType, EndType)) { Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) |