Preliminary support for function overloading
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57909 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/IdentifierResolver.cpp b/lib/Sema/IdentifierResolver.cpp
index e97de73..8375720 100644
--- a/lib/Sema/IdentifierResolver.cpp
+++ b/lib/Sema/IdentifierResolver.cpp
@@ -57,7 +57,9 @@
if (EnumConstantDecl *EnumD = dyn_cast<EnumConstantDecl>(D)) {
Ctx = EnumD->getDeclContext()->getParent();
} else if (ScopedDecl *SD = dyn_cast<ScopedDecl>(D))
- Ctx = SD->getDeclContext();
+ Ctx = SD->getDeclContext();
+ else if (OverloadedFunctionDecl *Ovl = dyn_cast<OverloadedFunctionDecl>(D))
+ Ctx = Ovl->getDeclContext();
else
return TUCtx();
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 796ba4e..039571f 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -17,6 +17,7 @@
#include "IdentifierResolver.h"
#include "CXXFieldCollector.h"
+#include "SemaOverload.h"
#include "clang/Parse/Action.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/DenseSet.h"
@@ -361,7 +362,46 @@
VarDecl *MergeVarDecl(VarDecl *New, Decl *Old);
FunctionDecl *MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old);
void CheckForFileScopedRedefinitions(Scope *S, VarDecl *VD);
-
+
+ /// C++ Overloading.
+ bool IsOverload(FunctionDecl *New, Decl* OldD,
+ OverloadedFunctionDecl::function_iterator &MatchedDecl);
+ ImplicitConversionSequence TryCopyInitialization(Expr* From, QualType ToType);
+ bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);
+ bool IsFloatingPointPromotion(QualType FromType, QualType ToType);
+ bool IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
+ QualType& ConvertedType);
+
+ ImplicitConversionSequence::CompareKind
+ CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1,
+ const ImplicitConversionSequence& ICS2);
+
+ ImplicitConversionSequence::CompareKind
+ CompareStandardConversionSequences(const StandardConversionSequence& SCS1,
+ const StandardConversionSequence& SCS2);
+
+ /// OverloadingResult - Capture the result of performing overload
+ /// resolution.
+ enum OverloadingResult {
+ OR_Success, ///< Overload resolution succeeded.
+ OR_No_Viable_Function, ///< No viable function found.
+ OR_Ambiguous ///< Ambiguous candidates found.
+ };
+
+ void AddOverloadCandidate(FunctionDecl *Function,
+ Expr **Args, unsigned NumArgs,
+ OverloadCandidateSet& CandidateSet);
+ void AddOverloadCandidates(OverloadedFunctionDecl *Ovl,
+ Expr **Args, unsigned NumArgs,
+ OverloadCandidateSet& CandidateSet);
+ bool isBetterOverloadCandidate(const OverloadCandidate& Cand1,
+ const OverloadCandidate& Cand2);
+ OverloadingResult BestViableFunction(OverloadCandidateSet& CandidateSet,
+ OverloadCandidateSet::iterator& Best);
+ void PrintOverloadCandidates(OverloadCandidateSet& CandidateSet,
+ bool OnlyViable);
+
+
/// Helpers for dealing with function parameters
bool CheckParmsForFunctionDef(FunctionDecl *FD);
void CheckCXXDefaultArguments(FunctionDecl *FD);
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index e32da24..1befc2e 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -95,7 +95,41 @@
IdResolver.AddShadowedDecl(TD, *I);
return;
}
+ } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+ // We are pushing the name of a function, which might be an
+ // overloaded name.
+ IdentifierResolver::iterator
+ I = IdResolver.begin(FD->getIdentifier(),
+ FD->getDeclContext(), false/*LookInParentCtx*/);
+ if (I != IdResolver.end() &&
+ IdResolver.isDeclInScope(*I, FD->getDeclContext(), S) &&
+ (isa<OverloadedFunctionDecl>(*I) || isa<FunctionDecl>(*I))) {
+ // There is already a declaration with the same name in the same
+ // scope. It must be a function or an overloaded function.
+ OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(*I);
+ if (!Ovl) {
+ // We haven't yet overloaded this function. Take the existing
+ // FunctionDecl and put it into an OverloadedFunctionDecl.
+ Ovl = OverloadedFunctionDecl::Create(Context,
+ FD->getDeclContext(),
+ FD->getIdentifier());
+ Ovl->addOverload(dyn_cast<FunctionDecl>(*I));
+
+ // Remove the name binding to the existing FunctionDecl...
+ IdResolver.RemoveDecl(*I);
+
+ // ... and put the OverloadedFunctionDecl in its place.
+ IdResolver.AddDecl(Ovl);
+ }
+
+ // We have an OverloadedFunctionDecl. Add the new FunctionDecl
+ // to its list of overloads.
+ Ovl->addOverload(FD);
+
+ return;
+ }
}
+
IdResolver.AddDecl(D);
}
@@ -320,9 +354,17 @@
/// declarator D which has the same name and scope as a previous
/// declaration 'Old'. Figure out how to resolve this situation,
/// merging decls or emitting diagnostics as appropriate.
-/// Redeclaration will be set true if thisNew is a redeclaration OldD.
+/// Redeclaration will be set true if this New is a redeclaration OldD.
+///
+/// In C++, New and Old must be declarations that are not
+/// overloaded. Use IsOverload to determine whether New and Old are
+/// overloaded, and to select the Old declaration that New should be
+/// merged with.
FunctionDecl *
Sema::MergeFunctionDecl(FunctionDecl *New, Decl *OldD, bool &Redeclaration) {
+ assert(!isa<OverloadedFunctionDecl>(OldD) &&
+ "Cannot merge with an overloaded function declaration");
+
Redeclaration = false;
// Verify the old decl was also a function.
FunctionDecl *Old = dyn_cast<FunctionDecl>(OldD);
@@ -332,17 +374,59 @@
Diag(OldD->getLocation(), diag::err_previous_definition);
return New;
}
+
+ // Determine whether the previous declaration was a definition,
+ // implicit declaration, or a declaration.
+ diag::kind PrevDiag;
+ if (Old->isThisDeclarationADefinition())
+ PrevDiag = diag::err_previous_definition;
+ else if (Old->isImplicit())
+ PrevDiag = diag::err_previous_implicit_declaration;
+ else
+ PrevDiag = diag::err_previous_declaration;
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
- // C++ [dcl.fct]p3:
- // All declarations for a function shall agree exactly in both the
- // return type and the parameter-type-list.
- if (getLangOptions().CPlusPlus && OldQType == NewQType) {
- MergeAttributes(New, Old);
- Redeclaration = true;
- return MergeCXXFunctionDecl(New, Old);
+ if (getLangOptions().CPlusPlus) {
+ // (C++98 13.1p2):
+ // Certain function declarations cannot be overloaded:
+ // -- Function declarations that differ only in the return type
+ // cannot be overloaded.
+ QualType OldReturnType
+ = cast<FunctionType>(OldQType.getTypePtr())->getResultType();
+ QualType NewReturnType
+ = cast<FunctionType>(NewQType.getTypePtr())->getResultType();
+ if (OldReturnType != NewReturnType) {
+ Diag(New->getLocation(), diag::err_ovl_diff_return_type);
+ Diag(Old->getLocation(), PrevDiag);
+ return New;
+ }
+
+ const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
+ const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
+ if (OldMethod && NewMethod) {
+ // -- Member function declarations with the same name and the
+ // same parameter types cannot be overloaded if any of them
+ // is a static member function declaration.
+ if (OldMethod->isStatic() || NewMethod->isStatic()) {
+ Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
+ Diag(Old->getLocation(), PrevDiag);
+ return New;
+ }
+ }
+
+ // (C++98 8.3.5p3):
+ // All declarations for a function shall agree exactly in both the
+ // return type and the parameter-type-list.
+ if (OldQType == NewQType) {
+ // We have a redeclaration.
+ MergeAttributes(New, Old);
+ Redeclaration = true;
+ return MergeCXXFunctionDecl(New, Old);
+ }
+
+ // Fall through for conflicting redeclarations and redefinitions.
}
// C: Function types need to be compatible, not identical. This handles
@@ -356,13 +440,6 @@
// A function that has already been declared has been redeclared or defined
// with a different type- show appropriate diagnostic
- diag::kind PrevDiag;
- if (Old->isThisDeclarationADefinition())
- PrevDiag = diag::err_previous_definition;
- else if (Old->isImplicit())
- PrevDiag = diag::err_previous_implicit_declaration;
- else
- PrevDiag = diag::err_previous_declaration;
// TODO: CHECK FOR CONFLICTS, multiple decls with same name in one scope.
// TODO: This is totally simplistic. It should handle merging functions
@@ -717,10 +794,49 @@
if (PrevDecl &&
(!getLangOptions().CPlusPlus||isDeclInScope(PrevDecl, CurContext, S))) {
bool Redeclaration = false;
- NewFD = MergeFunctionDecl(NewFD, PrevDecl, Redeclaration);
- if (NewFD == 0) return 0;
- if (Redeclaration) {
- NewFD->setPreviousDeclaration(cast<FunctionDecl>(PrevDecl));
+
+ // If C++, determine whether NewFD is an overload of PrevDecl or
+ // a declaration that requires merging. If it's an overload,
+ // there's no more work to do here; we'll just add the new
+ // function to the scope.
+ OverloadedFunctionDecl::function_iterator MatchedDecl;
+ if (!getLangOptions().CPlusPlus ||
+ !IsOverload(NewFD, PrevDecl, MatchedDecl)) {
+ Decl *OldDecl = PrevDecl;
+
+ // If PrevDecl was an overloaded function, extract the
+ // FunctionDecl that matched.
+ if (isa<OverloadedFunctionDecl>(PrevDecl))
+ OldDecl = *MatchedDecl;
+
+ // NewFD and PrevDecl represent declarations that need to be
+ // merged.
+ NewFD = MergeFunctionDecl(NewFD, OldDecl, Redeclaration);
+
+ if (NewFD == 0) return 0;
+ if (Redeclaration) {
+ NewFD->setPreviousDeclaration(cast<FunctionDecl>(OldDecl));
+
+ if (OldDecl == PrevDecl) {
+ // Remove the name binding for the previous
+ // declaration. We'll add the binding back later, but then
+ // it will refer to the new declaration (which will
+ // contain more information).
+ IdResolver.RemoveDecl(cast<NamedDecl>(PrevDecl));
+ } else {
+ // We need to update the OverloadedFunctionDecl with the
+ // latest declaration of this function, so that name
+ // lookup will always refer to the latest declaration of
+ // this function.
+ *MatchedDecl = NewFD;
+
+ // Add the redeclaration to the current scope, since we'll
+ // be skipping PushOnScopeChains.
+ S->AddDecl(NewFD);
+
+ return NewFD;
+ }
+ }
}
}
New = NewFD;
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index e06761f..fef205c 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -19,6 +19,7 @@
#include "clang/Basic/Diagnostic.h"
#include "clang/Parse/DeclSpec.h"
#include "llvm/Support/Compiler.h"
+#include <algorithm> // for std::equal
using namespace clang;
@@ -58,7 +59,7 @@
/// determine whether this declaration can be used in the default
/// argument expression.
bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
- ValueDecl *Decl = DRE->getDecl();
+ NamedDecl *Decl = DRE->getDecl();
if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
// C++ [dcl.fct.default]p9
// Default arguments are evaluated each time the function is
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 5ff8b0e..8c63060 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -418,6 +418,9 @@
return Diag(Loc, diag::err_unexpected_namespace, II.getName());
// Make the DeclRefExpr or BlockDeclRefExpr for the decl.
+ if (OverloadedFunctionDecl *Ovl = dyn_cast<OverloadedFunctionDecl>(D))
+ return new DeclRefExpr(Ovl, Context.OverloadTy, Loc);
+
ValueDecl *VD = cast<ValueDecl>(D);
// check if referencing an identifier with __attribute__((deprecated)).
@@ -1036,16 +1039,67 @@
Expr **Args = reinterpret_cast<Expr**>(args);
assert(Fn && "no function call expression");
FunctionDecl *FDecl = NULL;
+ OverloadedFunctionDecl *Ovl = NULL;
+
+ // If we're directly calling a function or a set of overloaded
+ // functions, get the appropriate declaration.
+ {
+ DeclRefExpr *DRExpr = NULL;
+ if (ImplicitCastExpr *IcExpr = dyn_cast<ImplicitCastExpr>(Fn))
+ DRExpr = dyn_cast<DeclRefExpr>(IcExpr->getSubExpr());
+ else
+ DRExpr = dyn_cast<DeclRefExpr>(Fn);
+
+ if (DRExpr) {
+ FDecl = dyn_cast<FunctionDecl>(DRExpr->getDecl());
+ Ovl = dyn_cast<OverloadedFunctionDecl>(DRExpr->getDecl());
+ }
+ }
+
+ // If we have a set of overloaded functions, perform overload
+ // resolution to pick the function.
+ if (Ovl) {
+ OverloadCandidateSet CandidateSet;
+ OverloadCandidateSet::iterator Best;
+ AddOverloadCandidates(Ovl, Args, NumArgs, CandidateSet);
+ switch (BestViableFunction(CandidateSet, Best)) {
+ case OR_Success:
+ {
+ // Success! Let the remainder of this function build a call to
+ // the function selected by overload resolution.
+ FDecl = Best->Function;
+ Expr *NewFn = new DeclRefExpr(FDecl, FDecl->getType(),
+ Fn->getSourceRange().getBegin());
+ delete Fn;
+ Fn = NewFn;
+ }
+ break;
+
+ case OR_No_Viable_Function:
+ if (CandidateSet.empty())
+ Diag(Fn->getSourceRange().getBegin(),
+ diag::err_ovl_no_viable_function_in_call, Ovl->getName(),
+ Fn->getSourceRange());
+ else {
+ Diag(Fn->getSourceRange().getBegin(),
+ diag::err_ovl_no_viable_function_in_call_with_cands,
+ Ovl->getName(), Fn->getSourceRange());
+ PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
+ }
+ return true;
+
+ case OR_Ambiguous:
+ Diag(Fn->getSourceRange().getBegin(),
+ diag::err_ovl_ambiguous_call, Ovl->getName(),
+ Fn->getSourceRange());
+ PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true);
+ return true;
+ }
+ }
// Promote the function operand.
UsualUnaryConversions(Fn);
- // If we're directly calling a function, get the declaration for
- // that function.
- if (ImplicitCastExpr *IcExpr = dyn_cast<ImplicitCastExpr>(Fn))
- if (DeclRefExpr *DRExpr = dyn_cast<DeclRefExpr>(IcExpr->getSubExpr()))
- FDecl = dyn_cast<FunctionDecl>(DRExpr->getDecl());
-
// Make the call expr early, before semantic checks. This guarantees cleanup
// of arguments and function on error.
llvm::OwningPtr<CallExpr> TheCall(new CallExpr(Fn, Args, NumArgs,
@@ -2338,7 +2392,7 @@
/// - *(x + 1) -> x, if x is an array
/// - &"123"[2] -> 0
/// - & __real__ x -> x
-static ValueDecl *getPrimaryDecl(Expr *E) {
+static NamedDecl *getPrimaryDecl(Expr *E) {
switch (E->getStmtClass()) {
case Stmt::DeclRefExprClass:
return cast<DeclRefExpr>(E)->getDecl();
@@ -2351,7 +2405,8 @@
case Stmt::ArraySubscriptExprClass: {
// &X[4] and &4[X] refers to X if X is not a pointer.
- ValueDecl *VD = getPrimaryDecl(cast<ArraySubscriptExpr>(E)->getBase());
+ NamedDecl *D = getPrimaryDecl(cast<ArraySubscriptExpr>(E)->getBase());
+ ValueDecl *VD = dyn_cast<ValueDecl>(D);
if (!VD || VD->getType()->isPointerType())
return 0;
else
@@ -2363,10 +2418,13 @@
switch(UO->getOpcode()) {
case UnaryOperator::Deref: {
// *(X + 1) refers to X if X is not a pointer.
- ValueDecl *VD = getPrimaryDecl(UO->getSubExpr());
- if (!VD || VD->getType()->isPointerType())
- return 0;
- return VD;
+ if (NamedDecl *D = getPrimaryDecl(UO->getSubExpr())) {
+ ValueDecl *VD = dyn_cast<ValueDecl>(D);
+ if (!VD || VD->getType()->isPointerType())
+ return 0;
+ return VD;
+ }
+ return 0;
}
case UnaryOperator::Real:
case UnaryOperator::Imag:
@@ -2420,7 +2478,7 @@
// Technically, there should be a check for array subscript
// expressions here, but the result of one is always an lvalue anyway.
}
- ValueDecl *dcl = getPrimaryDecl(op);
+ NamedDecl *dcl = getPrimaryDecl(op);
Expr::isLvalueResult lval = op->isLvalue(Context);
if (lval != Expr::LV_Valid) { // C99 6.5.3.2p1
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
new file mode 100644
index 0000000..88c209b
--- /dev/null
+++ b/lib/Sema/SemaOverload.cpp
@@ -0,0 +1,903 @@
+//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides Sema routines for C++ overloading.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sema.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Expr.h"
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
+
+namespace clang {
+
+/// GetConversionCategory - Retrieve the implicit conversion
+/// category corresponding to the given implicit conversion kind.
+ImplicitConversionCategory
+GetConversionCategory(ImplicitConversionKind Kind) {
+ static const ImplicitConversionCategory
+ Category[(int)ICK_Num_Conversion_Kinds] = {
+ ICC_Identity,
+ ICC_Lvalue_Transformation,
+ ICC_Lvalue_Transformation,
+ ICC_Lvalue_Transformation,
+ ICC_Qualification_Adjustment,
+ ICC_Promotion,
+ ICC_Promotion,
+ ICC_Conversion,
+ ICC_Conversion,
+ ICC_Conversion,
+ ICC_Conversion,
+ ICC_Conversion,
+ ICC_Conversion
+ };
+ return Category[(int)Kind];
+}
+
+/// GetConversionRank - Retrieve the implicit conversion rank
+/// corresponding to the given implicit conversion kind.
+ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) {
+ static const ImplicitConversionRank
+ Rank[(int)ICK_Num_Conversion_Kinds] = {
+ ICR_Exact_Match,
+ ICR_Exact_Match,
+ ICR_Exact_Match,
+ ICR_Exact_Match,
+ ICR_Exact_Match,
+ ICR_Promotion,
+ ICR_Promotion,
+ ICR_Conversion,
+ ICR_Conversion,
+ ICR_Conversion,
+ ICR_Conversion,
+ ICR_Conversion,
+ ICR_Conversion
+ };
+ return Rank[(int)Kind];
+}
+
+/// GetImplicitConversionName - Return the name of this kind of
+/// implicit conversion.
+const char* GetImplicitConversionName(ImplicitConversionKind Kind) {
+ static const char* Name[(int)ICK_Num_Conversion_Kinds] = {
+ "No conversion",
+ "Lvalue-to-rvalue",
+ "Array-to-pointer",
+ "Function-to-pointer",
+ "Qualification",
+ "Integral promotion",
+ "Floating point promotion",
+ "Integral conversion",
+ "Floating conversion",
+ "Floating-integral conversion",
+ "Pointer conversion",
+ "Pointer-to-member conversion",
+ "Boolean conversion"
+ };
+ return Name[Kind];
+}
+
+/// getRank - Retrieve the rank of this standard conversion sequence
+/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the
+/// implicit conversions.
+ImplicitConversionRank StandardConversionSequence::getRank() const {
+ ImplicitConversionRank Rank = ICR_Exact_Match;
+ if (GetConversionRank(First) > Rank)
+ Rank = GetConversionRank(First);
+ if (GetConversionRank(Second) > Rank)
+ Rank = GetConversionRank(Second);
+ if (GetConversionRank(Third) > Rank)
+ Rank = GetConversionRank(Third);
+ return Rank;
+}
+
+/// isPointerConversionToBool - Determines whether this conversion is
+/// a conversion of a pointer or pointer-to-member to bool. This is
+/// used as part of the ranking of standard conversion sequences
+/// (C++ 13.3.3.2p4).
+bool StandardConversionSequence::isPointerConversionToBool() const
+{
+ QualType FromType = QualType::getFromOpaquePtr(FromTypePtr);
+ QualType ToType = QualType::getFromOpaquePtr(ToTypePtr);
+
+ // Note that FromType has not necessarily been transformed by the
+ // array-to-pointer or function-to-pointer implicit conversions, so
+ // check for their presence as well as checking whether FromType is
+ // a pointer.
+ if (ToType->isBooleanType() &&
+ (FromType->isPointerType() ||
+ First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer))
+ return true;
+
+ return false;
+}
+
+/// DebugPrint - Print this standard conversion sequence to standard
+/// error. Useful for debugging overloading issues.
+void StandardConversionSequence::DebugPrint() const {
+ bool PrintedSomething = false;
+ if (First != ICK_Identity) {
+ fprintf(stderr, "%s", GetImplicitConversionName(First));
+ PrintedSomething = true;
+ }
+
+ if (Second != ICK_Identity) {
+ if (PrintedSomething) {
+ fprintf(stderr, " -> ");
+ }
+ fprintf(stderr, "%s", GetImplicitConversionName(Second));
+ PrintedSomething = true;
+ }
+
+ if (Third != ICK_Identity) {
+ if (PrintedSomething) {
+ fprintf(stderr, " -> ");
+ }
+ fprintf(stderr, "%s", GetImplicitConversionName(Third));
+ PrintedSomething = true;
+ }
+
+ if (!PrintedSomething) {
+ fprintf(stderr, "No conversions required");
+ }
+}
+
+/// DebugPrint - Print this user-defined conversion sequence to standard
+/// error. Useful for debugging overloading issues.
+void UserDefinedConversionSequence::DebugPrint() const {
+ if (Before.First || Before.Second || Before.Third) {
+ Before.DebugPrint();
+ fprintf(stderr, " -> ");
+ }
+ fprintf(stderr, "'%s'", ConversionFunction->getName());
+ if (After.First || After.Second || After.Third) {
+ fprintf(stderr, " -> ");
+ After.DebugPrint();
+ }
+}
+
+/// DebugPrint - Print this implicit conversion sequence to standard
+/// error. Useful for debugging overloading issues.
+void ImplicitConversionSequence::DebugPrint() const {
+ switch (ConversionKind) {
+ case StandardConversion:
+ fprintf(stderr, "Standard conversion: ");
+ Standard.DebugPrint();
+ break;
+ case UserDefinedConversion:
+ fprintf(stderr, "User-defined conversion: ");
+ UserDefined.DebugPrint();
+ break;
+ case EllipsisConversion:
+ fprintf(stderr, "Ellipsis conversion");
+ break;
+ case BadConversion:
+ fprintf(stderr, "Bad conversion");
+ break;
+ }
+
+ fprintf(stderr, "\n");
+}
+
+// IsOverload - Determine whether the given New declaration is an
+// overload of the Old declaration. This routine returns false if New
+// and Old cannot be overloaded, e.g., if they are functions with the
+// same signature (C++ 1.3.10) or if the Old declaration isn't a
+// function (or overload set). When it does return false and Old is an
+// OverloadedFunctionDecl, MatchedDecl will be set to point to the
+// FunctionDecl that New cannot be overloaded with.
+//
+// Example: Given the following input:
+//
+// void f(int, float); // #1
+// void f(int, int); // #2
+// int f(int, int); // #3
+//
+// When we process #1, there is no previous declaration of "f",
+// so IsOverload will not be used.
+//
+// When we process #2, Old is a FunctionDecl for #1. By comparing the
+// parameter types, we see that #1 and #2 are overloaded (since they
+// have different signatures), so this routine returns false;
+// MatchedDecl is unchanged.
+//
+// When we process #3, Old is an OverloadedFunctionDecl containing #1
+// and #2. We compare the signatures of #3 to #1 (they're overloaded,
+// so we do nothing) and then #3 to #2. Since the signatures of #3 and
+// #2 are identical (return types of functions are not part of the
+// signature), IsOverload returns false and MatchedDecl will be set to
+// point to the FunctionDecl for #2.
+bool
+Sema::IsOverload(FunctionDecl *New, Decl* OldD,
+ OverloadedFunctionDecl::function_iterator& MatchedDecl)
+{
+ if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) {
+ // Is this new function an overload of every function in the
+ // overload set?
+ OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(),
+ FuncEnd = Ovl->function_end();
+ for (; Func != FuncEnd; ++Func) {
+ if (!IsOverload(New, *Func, MatchedDecl)) {
+ MatchedDecl = Func;
+ return false;
+ }
+ }
+
+ // This function overloads every function in the overload set.
+ return true;
+ } else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) {
+ // Is the function New an overload of the function Old?
+ QualType OldQType = Context.getCanonicalType(Old->getType());
+ QualType NewQType = Context.getCanonicalType(New->getType());
+
+ // Compare the signatures (C++ 1.3.10) of the two functions to
+ // determine whether they are overloads. If we find any mismatch
+ // in the signature, they are overloads.
+
+ // If either of these functions is a K&R-style function (no
+ // prototype), then we consider them to have matching signatures.
+ if (isa<FunctionTypeNoProto>(OldQType.getTypePtr()) ||
+ isa<FunctionTypeNoProto>(NewQType.getTypePtr()))
+ return false;
+
+ FunctionTypeProto* OldType = cast<FunctionTypeProto>(OldQType.getTypePtr());
+ FunctionTypeProto* NewType = cast<FunctionTypeProto>(NewQType.getTypePtr());
+
+ // The signature of a function includes the types of its
+ // parameters (C++ 1.3.10), which includes the presence or absence
+ // of the ellipsis; see C++ DR 357).
+ if (OldQType != NewQType &&
+ (OldType->getNumArgs() != NewType->getNumArgs() ||
+ OldType->isVariadic() != NewType->isVariadic() ||
+ !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(),
+ NewType->arg_type_begin())))
+ return true;
+
+ // If the function is a class member, its signature includes the
+ // cv-qualifiers (if any) on the function itself.
+ //
+ // As part of this, also check whether one of the member functions
+ // is static, in which case they are not overloads (C++
+ // 13.1p2). While not part of the definition of the signature,
+ // this check is important to determine whether these functions
+ // can be overloaded.
+ CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old);
+ CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New);
+ if (OldMethod && NewMethod &&
+ !OldMethod->isStatic() && !NewMethod->isStatic() &&
+ OldQType.getCVRQualifiers() != NewQType.getCVRQualifiers())
+ return true;
+
+ // The signatures match; this is not an overload.
+ return false;
+ } else {
+ // (C++ 13p1):
+ // Only function declarations can be overloaded; object and type
+ // declarations cannot be overloaded.
+ return false;
+ }
+}
+
+/// TryCopyInitialization - Attempt to copy-initialize a value of the
+/// given type (ToType) from the given expression (Expr), as one would
+/// do when copy-initializing a function parameter. This function
+/// returns an implicit conversion sequence that can be used to
+/// perform the initialization. Given
+///
+/// void f(float f);
+/// void g(int i) { f(i); }
+///
+/// this routine would produce an implicit conversion sequence to
+/// describe the initialization of f from i, which will be a standard
+/// conversion sequence containing an lvalue-to-rvalue conversion (C++
+/// 4.1) followed by a floating-integral conversion (C++ 4.9).
+//
+/// Note that this routine only determines how the conversion can be
+/// performed; it does not actually perform the conversion. As such,
+/// it will not produce any diagnostics if no conversion is available,
+/// but will instead return an implicit conversion sequence of kind
+/// "BadConversion".
+ImplicitConversionSequence
+Sema::TryCopyInitialization(Expr* From, QualType ToType)
+{
+ ImplicitConversionSequence ICS;
+
+ QualType FromType = From->getType();
+
+ // Standard conversions (C++ 4)
+ ICS.ConversionKind = ImplicitConversionSequence::StandardConversion;
+ ICS.Standard.Deprecated = false;
+ ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr();
+
+ // The first conversion can be an lvalue-to-rvalue conversion,
+ // array-to-pointer conversion, or function-to-pointer conversion
+ // (C++ 4p1).
+
+ // Lvalue-to-rvalue conversion (C++ 4.1):
+ // An lvalue (3.10) of a non-function, non-array type T can be
+ // converted to an rvalue.
+ Expr::isLvalueResult argIsLvalue = From->isLvalue(Context);
+ if (argIsLvalue == Expr::LV_Valid &&
+ !FromType->isFunctionType() && !FromType->isArrayType()) {
+ ICS.Standard.First = ICK_Lvalue_To_Rvalue;
+
+ // If T is a non-class type, the type of the rvalue is the
+ // cv-unqualified version of T. Otherwise, the type of the rvalue
+ // is T (C++ 4.1p1).
+ if (!FromType->isRecordType())
+ FromType = FromType.getUnqualifiedType();
+ }
+ // Array-to-pointer conversion (C++ 4.2)
+ else if (FromType->isArrayType()) {
+ ICS.Standard.First = ICK_Array_To_Pointer;
+
+ // An lvalue or rvalue of type "array of N T" or "array of unknown
+ // bound of T" can be converted to an rvalue of type "pointer to
+ // T" (C++ 4.2p1).
+ FromType = Context.getArrayDecayedType(FromType);
+
+ if (IsStringLiteralToNonConstPointerConversion(From, ToType)) {
+ // This conversion is deprecated. (C++ D.4).
+ ICS.Standard.Deprecated = true;
+
+ // For the purpose of ranking in overload resolution
+ // (13.3.3.1.1), this conversion is considered an
+ // array-to-pointer conversion followed by a qualification
+ // conversion (4.4). (C++ 4.2p2)
+ ICS.Standard.Second = ICK_Identity;
+ ICS.Standard.Third = ICK_Qualification;
+ ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr();
+ return ICS;
+ }
+ }
+ // Function-to-pointer conversion (C++ 4.3).
+ else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) {
+ ICS.Standard.First = ICK_Function_To_Pointer;
+
+ // An lvalue of function type T can be converted to an rvalue of
+ // type "pointer to T." The result is a pointer to the
+ // function. (C++ 4.3p1).
+ FromType = Context.getPointerType(FromType);
+
+ // FIXME: Deal with overloaded functions here (C++ 4.3p2).
+ }
+ // We don't require any conversions for the first step.
+ else {
+ ICS.Standard.First = ICK_Identity;
+ }
+
+ // The second conversion can be an integral promotion, floating
+ // point promotion, integral conversion, floating point conversion,
+ // floating-integral conversion, pointer conversion,
+ // pointer-to-member conversion, or boolean conversion (C++ 4p1).
+ if (Context.getCanonicalType(FromType).getUnqualifiedType() ==
+ Context.getCanonicalType(ToType).getUnqualifiedType()) {
+ // The unqualified versions of the types are the same: there's no
+ // conversion to do.
+ ICS.Standard.Second = ICK_Identity;
+ }
+ // Integral promotion (C++ 4.5).
+ else if (IsIntegralPromotion(From, FromType, ToType)) {
+ ICS.Standard.Second = ICK_Integral_Promotion;
+ FromType = ToType.getUnqualifiedType();
+ }
+ // Floating point promotion (C++ 4.6).
+ else if (IsFloatingPointPromotion(FromType, ToType)) {
+ ICS.Standard.Second = ICK_Floating_Promotion;
+ FromType = ToType.getUnqualifiedType();
+ }
+ // Integral conversions (C++ 4.7).
+ else if ((FromType->isIntegralType() || FromType->isEnumeralType()) &&
+ (ToType->isIntegralType() || ToType->isEnumeralType())) {
+ ICS.Standard.Second = ICK_Integral_Conversion;
+ FromType = ToType.getUnqualifiedType();
+ }
+ // Floating point conversions (C++ 4.8).
+ else if (FromType->isFloatingType() && ToType->isFloatingType()) {
+ ICS.Standard.Second = ICK_Floating_Conversion;
+ FromType = ToType.getUnqualifiedType();
+ }
+ // Floating-integral conversions (C++ 4.9).
+ else if ((FromType->isFloatingType() &&
+ ToType->isIntegralType() && !ToType->isBooleanType()) ||
+ ((FromType->isIntegralType() || FromType->isEnumeralType()) &&
+ ToType->isFloatingType())) {
+ ICS.Standard.Second = ICK_Floating_Integral;
+ FromType = ToType.getUnqualifiedType();
+ }
+ // Pointer conversions (C++ 4.10).
+ else if (IsPointerConversion(From, FromType, ToType, FromType))
+ ICS.Standard.Second = ICK_Pointer_Conversion;
+ // FIXME: Pointer to member conversions (4.11).
+ // Boolean conversions (C++ 4.12).
+ // FIXME: pointer-to-member type
+ else if (ToType->isBooleanType() &&
+ (FromType->isArithmeticType() ||
+ FromType->isEnumeralType() ||
+ FromType->isPointerType())) {
+ ICS.Standard.Second = ICK_Boolean_Conversion;
+ FromType = Context.BoolTy;
+ } else {
+ // No second conversion required.
+ ICS.Standard.Second = ICK_Identity;
+ }
+
+ // The third conversion can be a qualification conversion (C++ 4p1).
+ // FIXME: CheckPointerTypesForAssignment isn't the right way to
+ // determine whether we have a qualification conversion.
+ if (Context.getCanonicalType(FromType) != Context.getCanonicalType(ToType)
+ && CheckPointerTypesForAssignment(ToType, FromType) == Compatible) {
+ ICS.Standard.Third = ICK_Qualification;
+ FromType = ToType;
+ } else {
+ // No conversion required
+ ICS.Standard.Third = ICK_Identity;
+ }
+
+ // If we have not converted the argument type to the parameter type,
+ // this is a bad conversion sequence.
+ if (Context.getCanonicalType(FromType) != Context.getCanonicalType(ToType))
+ ICS.ConversionKind = ImplicitConversionSequence::BadConversion;
+
+ ICS.Standard.ToTypePtr = FromType.getAsOpaquePtr();
+ return ICS;
+}
+
+/// IsIntegralPromotion - Determines whether the conversion from the
+/// expression From (whose potentially-adjusted type is FromType) to
+/// ToType is an integral promotion (C++ 4.5). If so, returns true and
+/// sets PromotedType to the promoted type.
+bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType)
+{
+ const BuiltinType *To = ToType->getAsBuiltinType();
+
+ // An rvalue of type char, signed char, unsigned char, short int, or
+ // unsigned short int can be converted to an rvalue of type int if
+ // int can represent all the values of the source type; otherwise,
+ // the source rvalue can be converted to an rvalue of type unsigned
+ // int (C++ 4.5p1).
+ if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && To) {
+ if (// We can promote any signed, promotable integer type to an int
+ (FromType->isSignedIntegerType() ||
+ // We can promote any unsigned integer type whose size is
+ // less than int to an int.
+ (!FromType->isSignedIntegerType() &&
+ Context.getTypeSize(FromType) < Context.getTypeSize(ToType))))
+ return To->getKind() == BuiltinType::Int;
+
+ return To->getKind() == BuiltinType::UInt;
+ }
+
+ // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2)
+ // can be converted to an rvalue of the first of the following types
+ // that can represent all the values of its underlying type: int,
+ // unsigned int, long, or unsigned long (C++ 4.5p2).
+ if ((FromType->isEnumeralType() || FromType->isWideCharType())
+ && ToType->isIntegerType()) {
+ // Determine whether the type we're converting from is signed or
+ // unsigned.
+ bool FromIsSigned;
+ uint64_t FromSize = Context.getTypeSize(FromType);
+ if (const EnumType *FromEnumType = FromType->getAsEnumType()) {
+ QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType();
+ FromIsSigned = UnderlyingType->isSignedIntegerType();
+ } else {
+ // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now.
+ FromIsSigned = true;
+ }
+
+ // The types we'll try to promote to, in the appropriate
+ // order. Try each of these types.
+ QualType PromoteTypes[4] = {
+ Context.IntTy, Context.UnsignedIntTy,
+ Context.LongTy, Context.UnsignedLongTy
+ };
+ for (int Idx = 0; Idx < 0; ++Idx) {
+ uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]);
+ if (FromSize < ToSize ||
+ (FromSize == ToSize &&
+ FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) {
+ // We found the type that we can promote to. If this is the
+ // type we wanted, we have a promotion. Otherwise, no
+ // promotion.
+ return Context.getCanonicalType(FromType).getUnqualifiedType()
+ == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType();
+ }
+ }
+ }
+
+ // An rvalue for an integral bit-field (9.6) can be converted to an
+ // rvalue of type int if int can represent all the values of the
+ // bit-field; otherwise, it can be converted to unsigned int if
+ // unsigned int can represent all the values of the bit-field. If
+ // the bit-field is larger yet, no integral promotion applies to
+ // it. If the bit-field has an enumerated type, it is treated as any
+ // other value of that type for promotion purposes (C++ 4.5p3).
+ if (MemberExpr *MemRef = dyn_cast<MemberExpr>(From)) {
+ using llvm::APSInt;
+ FieldDecl *MemberDecl = MemRef->getMemberDecl();
+ APSInt BitWidth;
+ if (MemberDecl->isBitField() &&
+ FromType->isIntegralType() && !FromType->isEnumeralType() &&
+ From->isIntegerConstantExpr(BitWidth, Context)) {
+ APSInt ToSize(Context.getTypeSize(ToType));
+
+ // Are we promoting to an int from a bitfield that fits in an int?
+ if (BitWidth < ToSize ||
+ (FromType->isSignedIntegerType() && BitWidth <= ToSize))
+ return To->getKind() == BuiltinType::Int;
+
+ // Are we promoting to an unsigned int from an unsigned bitfield
+ // that fits into an unsigned int?
+ if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize)
+ return To->getKind() == BuiltinType::UInt;
+
+ return false;
+ }
+ }
+
+ // An rvalue of type bool can be converted to an rvalue of type int,
+ // with false becoming zero and true becoming one (C++ 4.5p4).
+ if (FromType->isBooleanType() && To && To->getKind() == BuiltinType::Int)
+ return true;
+
+ return false;
+}
+
+/// IsFloatingPointPromotion - Determines whether the conversion from
+/// FromType to ToType is a floating point promotion (C++ 4.6). If so,
+/// returns true and sets PromotedType to the promoted type.
+bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType)
+{
+ /// An rvalue of type float can be converted to an rvalue of type
+ /// double. (C++ 4.6p1).
+ if (const BuiltinType *FromBuiltin = FromType->getAsBuiltinType())
+ if (const BuiltinType *ToBuiltin = ToType->getAsBuiltinType())
+ if (FromBuiltin->getKind() == BuiltinType::Float &&
+ ToBuiltin->getKind() == BuiltinType::Double)
+ return true;
+
+ return false;
+}
+
+/// IsPointerConversion - Determines whether the conversion of the
+/// expression From, which has the (possibly adjusted) type FromType,
+/// can be converted to the type ToType via a pointer conversion (C++
+/// 4.10). If so, returns true and places the converted type (that
+/// might differ from ToType in its cv-qualifiers at some level) into
+/// ConvertedType.
+bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
+ QualType& ConvertedType)
+{
+ const PointerType* ToTypePtr = ToType->getAsPointerType();
+ if (!ToTypePtr)
+ return false;
+
+ // A null pointer constant can be converted to a pointer type (C++ 4.10p1).
+ if (From->isNullPointerConstant(Context)) {
+ ConvertedType = ToType;
+ return true;
+ }
+
+ // An rvalue of type "pointer to cv T," where T is an object type,
+ // can be converted to an rvalue of type "pointer to cv void" (C++
+ // 4.10p2).
+ if (FromType->isPointerType() &&
+ FromType->getAsPointerType()->getPointeeType()->isObjectType() &&
+ ToTypePtr->getPointeeType()->isVoidType()) {
+ // We need to produce a pointer to cv void, where cv is the same
+ // set of cv-qualifiers as we had on the incoming pointee type.
+ QualType toPointee = ToTypePtr->getPointeeType();
+ unsigned Quals = Context.getCanonicalType(FromType)->getAsPointerType()
+ ->getPointeeType().getCVRQualifiers();
+
+ if (Context.getCanonicalType(ToTypePtr->getPointeeType()).getCVRQualifiers()
+ == Quals) {
+ // ToType is exactly the type we want. Use it.
+ ConvertedType = ToType;
+ } else {
+ // Build a new type with the right qualifiers.
+ ConvertedType
+ = Context.getPointerType(Context.VoidTy.getQualifiedType(Quals));
+ }
+ return true;
+ }
+
+ // FIXME: An rvalue of type "pointer to cv D," where D is a class
+ // type, can be converted to an rvalue of type "pointer to cv B,"
+ // where B is a base class (clause 10) of D (C++ 4.10p3).
+ return false;
+}
+
+/// CompareImplicitConversionSequences - Compare two implicit
+/// conversion sequences to determine whether one is better than the
+/// other or if they are indistinguishable (C++ 13.3.3.2).
+ImplicitConversionSequence::CompareKind
+Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1,
+ const ImplicitConversionSequence& ICS2)
+{
+ // (C++ 13.3.3.2p2): When comparing the basic forms of implicit
+ // conversion sequences (as defined in 13.3.3.1)
+ // -- a standard conversion sequence (13.3.3.1.1) is a better
+ // conversion sequence than a user-defined conversion sequence or
+ // an ellipsis conversion sequence, and
+ // -- a user-defined conversion sequence (13.3.3.1.2) is a better
+ // conversion sequence than an ellipsis conversion sequence
+ // (13.3.3.1.3).
+ //
+ if (ICS1.ConversionKind < ICS2.ConversionKind)
+ return ImplicitConversionSequence::Better;
+ else if (ICS2.ConversionKind < ICS1.ConversionKind)
+ return ImplicitConversionSequence::Worse;
+
+ // Two implicit conversion sequences of the same form are
+ // indistinguishable conversion sequences unless one of the
+ // following rules apply: (C++ 13.3.3.2p3):
+ if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion)
+ return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard);
+ else if (ICS1.ConversionKind ==
+ ImplicitConversionSequence::UserDefinedConversion) {
+ // User-defined conversion sequence U1 is a better conversion
+ // sequence than another user-defined conversion sequence U2 if
+ // they contain the same user-defined conversion function or
+ // constructor and if the second standard conversion sequence of
+ // U1 is better than the second standard conversion sequence of
+ // U2 (C++ 13.3.3.2p3).
+ if (ICS1.UserDefined.ConversionFunction ==
+ ICS2.UserDefined.ConversionFunction)
+ return CompareStandardConversionSequences(ICS1.UserDefined.After,
+ ICS2.UserDefined.After);
+ }
+
+ return ImplicitConversionSequence::Indistinguishable;
+}
+
+/// CompareStandardConversionSequences - Compare two standard
+/// conversion sequences to determine whether one is better than the
+/// other or if they are indistinguishable (C++ 13.3.3.2p3).
+ImplicitConversionSequence::CompareKind
+Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1,
+ const StandardConversionSequence& SCS2)
+{
+ // Standard conversion sequence S1 is a better conversion sequence
+ // than standard conversion sequence S2 if (C++ 13.3.3.2p3):
+
+ // -- S1 is a proper subsequence of S2 (comparing the conversion
+ // sequences in the canonical form defined by 13.3.3.1.1,
+ // excluding any Lvalue Transformation; the identity conversion
+ // sequence is considered to be a subsequence of any
+ // non-identity conversion sequence) or, if not that,
+ if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third)
+ // Neither is a proper subsequence of the other. Do nothing.
+ ;
+ else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) ||
+ (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) ||
+ (SCS1.Second == ICK_Identity &&
+ SCS1.Third == ICK_Identity))
+ // SCS1 is a proper subsequence of SCS2.
+ return ImplicitConversionSequence::Better;
+ else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) ||
+ (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) ||
+ (SCS2.Second == ICK_Identity &&
+ SCS2.Third == ICK_Identity))
+ // SCS2 is a proper subsequence of SCS1.
+ return ImplicitConversionSequence::Worse;
+
+ // -- the rank of S1 is better than the rank of S2 (by the rules
+ // defined below), or, if not that,
+ ImplicitConversionRank Rank1 = SCS1.getRank();
+ ImplicitConversionRank Rank2 = SCS2.getRank();
+ if (Rank1 < Rank2)
+ return ImplicitConversionSequence::Better;
+ else if (Rank2 < Rank1)
+ return ImplicitConversionSequence::Worse;
+ else {
+ // (C++ 13.3.3.2p4): Two conversion sequences with the same rank
+ // are indistinguishable unless one of the following rules
+ // applies:
+
+ // A conversion that is not a conversion of a pointer, or
+ // pointer to member, to bool is better than another conversion
+ // that is such a conversion.
+ if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool())
+ return SCS2.isPointerConversionToBool()
+ ? ImplicitConversionSequence::Better
+ : ImplicitConversionSequence::Worse;
+
+ // FIXME: The other bullets in (C++ 13.3.3.2p4) require support
+ // for derived classes.
+ }
+
+ // FIXME: Handle comparison by qualifications.
+ // FIXME: Handle comparison of reference bindings.
+ return ImplicitConversionSequence::Indistinguishable;
+}
+
+/// AddOverloadCandidate - Adds the given function to the set of
+/// candidate functions, using the given function call arguments.
+void
+Sema::AddOverloadCandidate(FunctionDecl *Function,
+ Expr **Args, unsigned NumArgs,
+ OverloadCandidateSet& CandidateSet)
+{
+ const FunctionTypeProto* Proto
+ = dyn_cast<FunctionTypeProto>(Function->getType()->getAsFunctionType());
+ assert(Proto && "Functions without a prototype cannot be overloaded");
+
+ // Add this candidate
+ CandidateSet.push_back(OverloadCandidate());
+ OverloadCandidate& Candidate = CandidateSet.back();
+ Candidate.Function = Function;
+
+ unsigned NumArgsInProto = Proto->getNumArgs();
+
+ // (C++ 13.3.2p2): A candidate function having fewer than m
+ // parameters is viable only if it has an ellipsis in its parameter
+ // list (8.3.5).
+ if (NumArgs > NumArgsInProto && !Proto->isVariadic()) {
+ Candidate.Viable = false;
+ return;
+ }
+
+ // (C++ 13.3.2p2): A candidate function having more than m parameters
+ // is viable only if the (m+1)st parameter has a default argument
+ // (8.3.6). For the purposes of overload resolution, the
+ // parameter list is truncated on the right, so that there are
+ // exactly m parameters.
+ unsigned MinRequiredArgs = Function->getMinRequiredArguments();
+ if (NumArgs < MinRequiredArgs) {
+ // Not enough arguments.
+ Candidate.Viable = false;
+ return;
+ }
+
+ // Determine the implicit conversion sequences for each of the
+ // arguments.
+ Candidate.Viable = true;
+ Candidate.Conversions.resize(NumArgs);
+ for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
+ if (ArgIdx < NumArgsInProto) {
+ // (C++ 13.3.2p3): for F to be a viable function, there shall
+ // exist for each argument an implicit conversion sequence
+ // (13.3.3.1) that converts that argument to the corresponding
+ // parameter of F.
+ QualType ParamType = Proto->getArgType(ArgIdx);
+ Candidate.Conversions[ArgIdx]
+ = TryCopyInitialization(Args[ArgIdx], ParamType);
+ if (Candidate.Conversions[ArgIdx].ConversionKind
+ == ImplicitConversionSequence::BadConversion)
+ Candidate.Viable = false;
+ } else {
+ // (C++ 13.3.2p2): For the purposes of overload resolution, any
+ // argument for which there is no corresponding parameter is
+ // considered to ""match the ellipsis" (C+ 13.3.3.1.3).
+ Candidate.Conversions[ArgIdx].ConversionKind
+ = ImplicitConversionSequence::EllipsisConversion;
+ }
+ }
+}
+
+/// AddOverloadCandidates - Add all of the function overloads in Ovl
+/// to the candidate set.
+void
+Sema::AddOverloadCandidates(OverloadedFunctionDecl *Ovl,
+ Expr **Args, unsigned NumArgs,
+ OverloadCandidateSet& CandidateSet)
+{
+ for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin();
+ Func != Ovl->function_end(); ++Func)
+ AddOverloadCandidate(*Func, Args, NumArgs, CandidateSet);
+}
+
+/// isBetterOverloadCandidate - Determines whether the first overload
+/// candidate is a better candidate than the second (C++ 13.3.3p1).
+bool
+Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1,
+ const OverloadCandidate& Cand2)
+{
+ // Define viable functions to be better candidates than non-viable
+ // functions.
+ if (!Cand2.Viable)
+ return Cand1.Viable;
+ else if (!Cand1.Viable)
+ return false;
+
+ // FIXME: Deal with the implicit object parameter for static member
+ // functions. (C++ 13.3.3p1).
+
+ // (C++ 13.3.3p1): a viable function F1 is defined to be a better
+ // function than another viable function F2 if for all arguments i,
+ // ICSi(F1) is not a worse conversion sequence than ICSi(F2), and
+ // then...
+ unsigned NumArgs = Cand1.Conversions.size();
+ assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch");
+ bool HasBetterConversion = false;
+ for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) {
+ switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx],
+ Cand2.Conversions[ArgIdx])) {
+ case ImplicitConversionSequence::Better:
+ // Cand1 has a better conversion sequence.
+ HasBetterConversion = true;
+ break;
+
+ case ImplicitConversionSequence::Worse:
+ // Cand1 can't be better than Cand2.
+ return false;
+
+ case ImplicitConversionSequence::Indistinguishable:
+ // Do nothing.
+ break;
+ }
+ }
+
+ if (HasBetterConversion)
+ return true;
+
+ // FIXME: Several other bullets in (C++ 13.3.3p1) need to be implemented.
+
+ return false;
+}
+
+/// BestViableFunction - Computes the best viable function (C++ 13.3.3)
+/// within an overload candidate set. If overloading is successful,
+/// the result will be OR_Success and Best will be set to point to the
+/// best viable function within the candidate set. Otherwise, one of
+/// several kinds of errors will be returned; see
+/// Sema::OverloadingResult.
+Sema::OverloadingResult
+Sema::BestViableFunction(OverloadCandidateSet& CandidateSet,
+ OverloadCandidateSet::iterator& Best)
+{
+ // Find the best viable function.
+ Best = CandidateSet.end();
+ for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
+ Cand != CandidateSet.end(); ++Cand) {
+ if (Cand->Viable) {
+ if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best))
+ Best = Cand;
+ }
+ }
+
+ // If we didn't find any viable functions, abort.
+ if (Best == CandidateSet.end())
+ return OR_No_Viable_Function;
+
+ // Make sure that this function is better than every other viable
+ // function. If not, we have an ambiguity.
+ for (OverloadCandidateSet::iterator Cand = CandidateSet.begin();
+ Cand != CandidateSet.end(); ++Cand) {
+ if (Cand->Viable &&
+ Cand != Best &&
+ !isBetterOverloadCandidate(*Best, *Cand))
+ return OR_Ambiguous;
+ }
+
+ // Best is the best viable function.
+ return OR_Success;
+}
+
+/// PrintOverloadCandidates - When overload resolution fails, prints
+/// diagnostic messages containing the candidates in the candidate
+/// set. If OnlyViable is true, only viable candidates will be printed.
+void
+Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet,
+ bool OnlyViable)
+{
+ OverloadCandidateSet::iterator Cand = CandidateSet.begin(),
+ LastCand = CandidateSet.end();
+ for (; Cand != LastCand; ++Cand) {
+ if (Cand->Viable ||!OnlyViable)
+ Diag(Cand->Function->getLocation(), diag::err_ovl_candidate);
+ }
+}
+
+} // end namespace clang
diff --git a/lib/Sema/SemaOverload.h b/lib/Sema/SemaOverload.h
new file mode 100644
index 0000000..8d7ccd2
--- /dev/null
+++ b/lib/Sema/SemaOverload.h
@@ -0,0 +1,199 @@
+//===--- Overload.h - C++ Overloading ---------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the data structures and types used in C++
+// overload resolution.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_OVERLOAD_H
+#define LLVM_CLANG_SEMA_OVERLOAD_H
+
+#include "llvm/ADT/SmallVector.h"
+
+namespace clang {
+ class FunctionDecl;
+
+ /// ImplicitConversionKind - The kind of implicit conversion used to
+ /// convert an argument to a parameter's type. The enumerator values
+ /// match with Table 9 of (C++ 13.3.3.1.1) and are listed such that
+ /// better conversion kinds have smaller values.
+ enum ImplicitConversionKind {
+ ICK_Identity = 0, ///< Identity conversion (no conversion)
+ ICK_Lvalue_To_Rvalue, ///< Lvalue-to-rvalue conversion (C++ 4.1)
+ ICK_Array_To_Pointer, ///< Array-to-pointer conversion (C++ 4.2)
+ ICK_Function_To_Pointer, ///< Function-to-pointer (C++ 4.3)
+ ICK_Qualification, ///< Qualification conversions (C++ 4.4)
+ ICK_Integral_Promotion, ///< Integral promotions (C++ 4.5)
+ ICK_Floating_Promotion, ///< Floating point promotions (C++ 4.6)
+ ICK_Integral_Conversion, ///< Integral conversions (C++ 4.7)
+ ICK_Floating_Conversion, ///< Floating point conversions (C++ 4.8)
+ ICK_Floating_Integral, ///< Floating-integral conversions (C++ 4.9)
+ ICK_Pointer_Conversion, ///< Pointer conversions (C++ 4.10)
+ ICK_Pointer_Member, ///< Pointer-to-member conversions (C++ 4.11)
+ ICK_Boolean_Conversion, ///< Boolean conversions (C++ 4.12)
+ ICK_Num_Conversion_Kinds ///< The number of conversion kinds
+ };
+
+ /// ImplicitConversionCategory - The category of an implicit
+ /// conversion kind. The enumerator values match with Table 9 of
+ /// (C++ 13.3.3.1.1) and are listed such that better conversion
+ /// categories have smaller values.
+ enum ImplicitConversionCategory {
+ ICC_Identity = 0, ///< Identity
+ ICC_Lvalue_Transformation, ///< Lvalue transformation
+ ICC_Qualification_Adjustment, ///< Qualification adjustment
+ ICC_Promotion, ///< Promotion
+ ICC_Conversion ///< Conversion
+ };
+
+ ImplicitConversionCategory
+ GetConversionCategory(ImplicitConversionKind Kind);
+
+ /// ImplicitConversionRank - The rank of an implicit conversion
+ /// kind. The enumerator values match with Table 9 of (C++
+ /// 13.3.3.1.1) and are listed such that better conversion ranks
+ /// have smaller values.
+ enum ImplicitConversionRank {
+ ICR_Exact_Match = 0, ///< Exact Match
+ ICR_Promotion, ///< Promotion
+ ICR_Conversion ///< Conversion
+ };
+
+ ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind);
+
+ /// StandardConversionSequence - represents a standard conversion
+ /// sequence (C++ 13.3.3.1.1). A standard conversion sequence
+ /// contains between zero and three conversions. If a particular
+ /// conversion is not needed, it will be set to the identity conversion
+ /// (ICK_Identity). Note that the three conversions are
+ /// specified as separate members (rather than in an array) so that
+ /// we can keep the size of a standard conversion sequence to a
+ /// single word.
+ struct StandardConversionSequence {
+ /// First -- The first conversion can be an lvalue-to-rvalue
+ /// conversion, array-to-pointer conversion, or
+ /// function-to-pointer conversion.
+ ImplicitConversionKind First : 8;
+
+ /// Second - The second conversion can be an integral promotion,
+ /// floating point promotion, integral conversion, floating point
+ /// conversion, floating-integral conversion, pointer conversion,
+ /// pointer-to-member conversion, or boolean conversion.
+ ImplicitConversionKind Second : 8;
+
+ /// Third - The third conversion can be a qualification conversion.
+ ImplicitConversionKind Third : 8;
+
+ /// Deprecated - Whether this is a deprecated conversion, such as
+ /// converting a string literal to a pointer to non-const
+ /// character data (C++ 4.2p2).
+ bool Deprecated : 1;
+
+ /// FromType - The type that this conversion is converting
+ /// from. This is an opaque pointer for that can be translated
+ /// into a QualType.
+ void *FromTypePtr;
+
+ /// ToType - The type that this conversion is converting to. This
+ /// is an opaque pointer for that can be translated into a
+ /// QualType.
+ void *ToTypePtr;
+
+ ImplicitConversionRank getRank() const;
+ bool isPointerConversionToBool() const;
+ void DebugPrint() const;
+ };
+
+ /// UserDefinedConversionSequence - Represents a user-defined
+ /// conversion sequence (C++ 13.3.3.1.2).
+ struct UserDefinedConversionSequence {
+ /// Before - Represents the standard conversion that occurs before
+ /// the actual user-defined conversion. (C++ 13.3.3.1.2p1):
+ ///
+ /// If the user-defined conversion is specified by a constructor
+ /// (12.3.1), the initial standard conversion sequence converts
+ /// the source type to the type required by the argument of the
+ /// constructor. If the user-defined conversion is specified by
+ /// a conversion function (12.3.2), the initial standard
+ /// conversion sequence converts the source type to the implicit
+ /// object parameter of the conversion function.
+ StandardConversionSequence Before;
+
+ /// After - Represents the standard conversion that occurs after
+ /// the actual user-defined conversion.
+ StandardConversionSequence After;
+
+ /// ConversionFunction - The function that will perform the
+ /// user-defined conversion.
+ FunctionDecl* ConversionFunction;
+
+ void DebugPrint() const;
+ };
+
+ /// ImplicitConversionSequence - Represents an implicit conversion
+ /// sequence, which may be a standard conversion sequence
+ // (C++ 13.3.3.1.1), user-defined conversion sequence (C++ 13.3.3.1.2),
+ /// or an ellipsis conversion sequence (C++ 13.3.3.1.3).
+ struct ImplicitConversionSequence {
+ /// Kind - The kind of implicit conversion sequence. BadConversion
+ /// specifies that there is no conversion from the source type to
+ /// the target type. The enumerator values are ordered such that
+ /// better implicit conversions have smaller values.
+ enum Kind {
+ StandardConversion = 0,
+ UserDefinedConversion,
+ EllipsisConversion,
+ BadConversion
+ };
+
+ /// ConversionKind - The kind of implicit conversion sequence.
+ Kind ConversionKind;
+
+ union {
+ /// When ConversionKind == StandardConversion, provides the
+ /// details of the standard conversion sequence.
+ StandardConversionSequence Standard;
+
+ /// When ConversionKind == UserDefinedConversion, provides the
+ /// details of the user-defined conversion sequence.
+ UserDefinedConversionSequence UserDefined;
+ };
+
+ // The result of a comparison between implicit conversion
+ // sequences. Use Sema::CompareImplicitConversionSequences to
+ // actually perform the comparison.
+ enum CompareKind {
+ Better,
+ Indistinguishable,
+ Worse
+ };
+
+ void DebugPrint() const;
+ };
+
+ /// OverloadCandidate - A single candidate in an overload set (C++ 13.3).
+ struct OverloadCandidate {
+ /// Function - The actual function that this candidate represents.
+ FunctionDecl *Function;
+
+ /// Conversions - The conversion sequences used to convert the
+ /// function arguments to the function parameters.
+ llvm::SmallVector<ImplicitConversionSequence, 4> Conversions;
+
+ /// Viable - True to indicate that this overload candidate is viable.
+ bool Viable;
+ };
+
+ /// OverloadCandidateSet - A set of overload candidates, used in C++
+ /// overload resolution (C++ 13.3).
+ typedef llvm::SmallVector<OverloadCandidate, 4> OverloadCandidateSet;
+} // end namespace clang
+
+#endif // LLVM_CLANG_SEMA_OVERLOAD_H