Fix our semantic analysis of
unqualified-id '('
in C++. The unqualified-id might not refer to any declaration in our
current scope, but declarations by that name might be found via
argument-dependent lookup. We now do so properly.
As part of this change, CXXDependentNameExpr, which was previously
designed to express the unqualified-id in the above constructor within
templates, has become UnresolvedFunctionNameExpr, which does
effectively the same thing but will work for both templates and
non-templates.
Additionally, we cope with all unqualified-ids, since ADL also applies
in cases like
operator+(x, y)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63733 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 3143b5c..6b8d852 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -517,12 +517,13 @@
bool Complain);
void FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn);
- FunctionDecl *ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Func,
+ FunctionDecl *ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee,
+ DeclarationName UnqualifiedName,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc,
- bool ArgumentDependentLookup);
+ bool &ArgumentDependentLookup);
ExprResult
BuildCallToMemberFunction(Scope *S, Expr *MemExpr,
SourceLocation LParenLoc, Expr **Args,
@@ -1068,7 +1069,6 @@
DeclarationName Name,
bool HasTrailingLParen,
const CXXScopeSpec *SS,
- bool ForceResolution = false,
bool isAddressOfOperand = false);
virtual OwningExprResult ActOnPredefinedExpr(SourceLocation Loc,
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 24f7965..c1e4c0e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -366,7 +366,7 @@
const CXXScopeSpec *SS,
bool isAddressOfOperand) {
return ActOnDeclarationNameExpr(S, Loc, &II, HasTrailingLParen, SS,
- /*ForceResolution*/false, isAddressOfOperand);
+ isAddressOfOperand);
}
/// BuildDeclRefExpr - Build either a DeclRefExpr or a
@@ -535,10 +535,6 @@
/// qualified-id (foo::bar) to indicate the class or namespace that
/// the identifier must be a member of.
///
-/// If ForceResolution is true, then we will attempt to resolve the
-/// name even if it looks like a dependent name. This option is off by
-/// default.
-///
/// isAddressOfOperand means that this expression is the direct operand
/// of an address-of operator. This matters because this is the only
/// situation where a qualified name referencing a non-static member may
@@ -546,27 +542,27 @@
Sema::OwningExprResult
Sema::ActOnDeclarationNameExpr(Scope *S, SourceLocation Loc,
DeclarationName Name, bool HasTrailingLParen,
- const CXXScopeSpec *SS, bool ForceResolution,
+ const CXXScopeSpec *SS,
bool isAddressOfOperand) {
- if (S->getTemplateParamParent() && Name.getAsIdentifierInfo() &&
- HasTrailingLParen && !SS && !ForceResolution) {
- // We've seen something of the form
- // identifier(
- // and we are in a template, so it is likely that 's' is a
- // dependent name. However, we won't know until we've parsed all
- // of the call arguments. So, build a CXXDependentNameExpr node
- // to represent this name. Then, if it turns out that none of the
- // arguments are type-dependent, we'll force the resolution of the
- // dependent name at that point.
- return Owned(new (Context) CXXDependentNameExpr(Name.getAsIdentifierInfo(),
- Context.DependentTy, Loc));
- }
-
// Could be enum-constant, value decl, instance variable, etc.
if (SS && SS->isInvalid())
return ExprError();
LookupResult Lookup = LookupParsedName(S, SS, Name, LookupOrdinaryName);
+ if (getLangOptions().CPlusPlus && (!SS || !SS->isSet()) &&
+ HasTrailingLParen && Lookup.getKind() == LookupResult::NotFound) {
+ // We've seen something of the form
+ //
+ // identifier(
+ //
+ // and we did not find any entity by the name
+ // "identifier". However, this identifier is still subject to
+ // argument-dependent lookup, so keep track of the name.
+ return Owned(new (Context) UnresolvedFunctionNameExpr(Name,
+ Context.OverloadTy,
+ Loc));
+ }
+
Decl *D = 0;
if (Lookup.isAmbiguous()) {
DiagnoseAmbiguousLookup(Lookup, Name, Loc,
@@ -1839,48 +1835,27 @@
Expr **Args = reinterpret_cast<Expr**>(args.release());
assert(Fn && "no function call expression");
FunctionDecl *FDecl = NULL;
-
- // Determine whether this is a dependent call inside a C++ template,
- // in which case we won't do any semantic analysis now.
- bool Dependent = false;
- if (Fn->isTypeDependent()) {
- if (CXXDependentNameExpr *FnName = dyn_cast<CXXDependentNameExpr>(Fn)) {
- if (Expr::hasAnyTypeDependentArguments(Args, NumArgs))
- Dependent = true;
- else {
- // Resolve the CXXDependentNameExpr to an actual identifier;
- // it wasn't really a dependent name after all.
- // FIXME: in the presence of ADL, this resolves too early.
- OwningExprResult Resolved
- = ActOnDeclarationNameExpr(S, FnName->getLocation(),
- FnName->getName(),
- /*HasTrailingLParen=*/true,
- /*SS=*/0,
- /*ForceResolution=*/true);
- if (Resolved.isInvalid())
- return ExprError();
- else {
- delete Fn;
- Fn = (Expr *)Resolved.release();
- }
- }
- } else
- Dependent = true;
- } else
- Dependent = Expr::hasAnyTypeDependentArguments(Args, NumArgs);
-
- // FIXME: Will need to cache the results of name lookup (including
- // ADL) in Fn.
- if (Dependent)
- return Owned(new (Context) CallExpr(Fn, Args, NumArgs,
- Context.DependentTy, RParenLoc));
-
- // Determine whether this is a call to an object (C++ [over.call.object]).
- if (getLangOptions().CPlusPlus && Fn->getType()->isRecordType())
- return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs,
- CommaLocs, RParenLoc));
+ DeclarationName UnqualifiedName;
if (getLangOptions().CPlusPlus) {
+ // Determine whether this is a dependent call inside a C++ template,
+ // in which case we won't do any semantic analysis now.
+ // FIXME: Will need to cache the results of name lookup (including ADL) in Fn.
+ bool Dependent = false;
+ if (Fn->isTypeDependent())
+ Dependent = true;
+ else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs))
+ Dependent = true;
+
+ if (Dependent)
+ return Owned(new (Context) CallExpr(Fn, Args, NumArgs,
+ Context.DependentTy, RParenLoc));
+
+ // Determine whether this is a call to an object (C++ [over.call.object]).
+ if (Fn->getType()->isRecordType())
+ return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs,
+ CommaLocs, RParenLoc));
+
// Determine whether this is a call to a member function.
if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(Fn->IgnoreParens()))
if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) ||
@@ -1897,7 +1872,8 @@
if (ImplicitCastExpr *IcExpr = dyn_cast<ImplicitCastExpr>(FnExpr))
FnExpr = IcExpr->getSubExpr();
else if (ParenExpr *PExpr = dyn_cast<ParenExpr>(FnExpr)) {
- // FIXME: Where does the C++ standard say this?
+ // Parentheses around a function disable ADL
+ // (C++0x [basic.lookup.argdep]p1).
ADL = false;
FnExpr = PExpr->getSubExpr();
} else if (isa<UnaryOperator>(FnExpr) &&
@@ -1905,32 +1881,39 @@
== UnaryOperator::AddrOf) {
FnExpr = cast<UnaryOperator>(FnExpr)->getSubExpr();
} else {
- DRExpr = dyn_cast<DeclRefExpr>(FnExpr);
+ if (isa<DeclRefExpr>(FnExpr)) {
+ DRExpr = cast<DeclRefExpr>(FnExpr);
+
+ // Qualified names disable ADL (C++0x [basic.lookup.argdep]p1).
+ ADL = ADL && !isa<QualifiedDeclRefExpr>(DRExpr);
+ }
+ else if (UnresolvedFunctionNameExpr *DepName
+ = dyn_cast<UnresolvedFunctionNameExpr>(FnExpr))
+ UnqualifiedName = DepName->getName();
+ else {
+ // Any kind of name that does not refer to a declaration (or
+ // set of declarations) disables ADL (C++0x [basic.lookup.argdep]p3).
+ ADL = false;
+ }
break;
}
}
- if (DRExpr)
+ OverloadedFunctionDecl *Ovl = 0;
+ if (DRExpr) {
FDecl = dyn_cast<FunctionDecl>(DRExpr->getDecl());
+ Ovl = dyn_cast<OverloadedFunctionDecl>(DRExpr->getDecl());
+ }
- if (getLangOptions().CPlusPlus && DRExpr &&
- (FDecl || isa<OverloadedFunctionDecl>(DRExpr->getDecl()))) {
- // C++ [basic.lookup.argdep]p1:
- // When an unqualified name is used as the postfix-expression in
- // a function call (5.2.2), other namespaces not considered
- // during the usual unqualified lookup (3.4.1) may be searched,
- // and namespace-scope friend func- tion declarations (11.4) not
- // otherwise visible may be found.
- if (DRExpr && isa<QualifiedDeclRefExpr>(DRExpr))
- ADL = false;
-
+ if (getLangOptions().CPlusPlus && (FDecl || Ovl || UnqualifiedName)) {
// We don't perform ADL for builtins.
if (FDecl && FDecl->getIdentifier() &&
FDecl->getIdentifier()->getBuiltinID())
ADL = false;
- if ((DRExpr && isa<OverloadedFunctionDecl>(DRExpr->getDecl())) || ADL) {
- FDecl = ResolveOverloadedCallFn(Fn, DRExpr->getDecl(), LParenLoc, Args,
+ if (Ovl || ADL) {
+ FDecl = ResolveOverloadedCallFn(Fn, DRExpr? DRExpr->getDecl() : 0,
+ UnqualifiedName, LParenLoc, Args,
NumArgs, CommaLocs, RParenLoc, ADL);
if (!FDecl)
return ExprError();
@@ -1938,7 +1921,7 @@
// Update Fn to refer to the actual function selected.
Expr *NewFn = 0;
if (QualifiedDeclRefExpr *QDRExpr
- = dyn_cast<QualifiedDeclRefExpr>(DRExpr))
+ = dyn_cast_or_null<QualifiedDeclRefExpr>(DRExpr))
NewFn = new (Context) QualifiedDeclRefExpr(FDecl, FDecl->getType(),
QDRExpr->getLocation(),
false, false,
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index e9dbc84..2a7c9a8 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -35,7 +35,7 @@
DeclarationName ConvName
= Context.DeclarationNames.getCXXConversionFunctionName(ConvTypeCanon);
return ActOnDeclarationNameExpr(S, OperatorLoc, ConvName, HasTrailingLParen,
- &SS, /*ForceRes*/false, isAddressOfOperand);
+ &SS, isAddressOfOperand);
}
/// ActOnCXXOperatorFunctionIdExpr - Parse a C++ overloaded operator
@@ -51,7 +51,7 @@
bool isAddressOfOperand) {
DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(Op);
return ActOnDeclarationNameExpr(S, OperatorLoc, Name, HasTrailingLParen, &SS,
- /*ForceRes*/false, isAddressOfOperand);
+ isAddressOfOperand);
}
/// ActOnCXXTypeidOfType - Parse typeid( type-id ).
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 293e9c3..01b9829 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -3503,20 +3503,56 @@
/// resolution. Otherwise, emits diagnostics, deletes all of the
/// arguments and Fn, and returns NULL.
FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee,
+ DeclarationName UnqualifiedName,
SourceLocation LParenLoc,
Expr **Args, unsigned NumArgs,
SourceLocation *CommaLocs,
SourceLocation RParenLoc,
- bool ArgumentDependentLookup) {
+ bool &ArgumentDependentLookup) {
OverloadCandidateSet CandidateSet;
+
+ // Add the functions denoted by Callee to the set of candidate
+ // functions. While we're doing so, track whether argument-dependent
+ // lookup still applies, per:
+ //
+ // C++0x [basic.lookup.argdep]p3:
+ // Let X be the lookup set produced by unqualified lookup (3.4.1)
+ // and let Y be the lookup set produced by argument dependent
+ // lookup (defined as follows). If X contains
+ //
+ // -- a declaration of a class member, or
+ //
+ // -- a block-scope function declaration that is not a
+ // using-declaration, or
+ //
+ // -- a declaration that is neither a function or a function
+ // template
+ //
+ // then Y is empty.
if (OverloadedFunctionDecl *Ovl
- = dyn_cast_or_null<OverloadedFunctionDecl>(Callee))
- AddOverloadCandidates(Ovl, Args, NumArgs, CandidateSet);
- else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee))
- AddOverloadCandidate(cast<FunctionDecl>(Func), Args, NumArgs, CandidateSet);
-
+ = dyn_cast_or_null<OverloadedFunctionDecl>(Callee)) {
+ for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(),
+ FuncEnd = Ovl->function_end();
+ Func != FuncEnd; ++Func) {
+ AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet);
+
+ if ((*Func)->getDeclContext()->isRecord() ||
+ (*Func)->getDeclContext()->isFunctionOrMethod())
+ ArgumentDependentLookup = false;
+ }
+ } else if (FunctionDecl *Func = dyn_cast_or_null<FunctionDecl>(Callee)) {
+ AddOverloadCandidate(Func, Args, NumArgs, CandidateSet);
+
+ if (Func->getDeclContext()->isRecord() ||
+ Func->getDeclContext()->isFunctionOrMethod())
+ ArgumentDependentLookup = false;
+ }
+
+ if (Callee)
+ UnqualifiedName = Callee->getDeclName();
+
if (ArgumentDependentLookup)
- AddArgumentDependentLookupCandidates(Callee->getDeclName(), Args, NumArgs,
+ AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs,
CandidateSet);
OverloadCandidateSet::iterator Best;
@@ -3527,14 +3563,14 @@
case OR_No_Viable_Function:
Diag(Fn->getSourceRange().getBegin(),
diag::err_ovl_no_viable_function_in_call)
- << Callee->getDeclName() << (unsigned)CandidateSet.size()
+ << UnqualifiedName << (unsigned)CandidateSet.size()
<< Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
break;
case OR_Ambiguous:
Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call)
- << Callee->getDeclName() << Fn->getSourceRange();
+ << UnqualifiedName << Fn->getSourceRange();
PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
break;
}