When overload resolution fails for an overloaded operator, show the
overload candidates (but not the built-in ones). We still rely on the
underlying built-in semantic analysis to produce the initial
diagnostic, then print the candidates following that diagnostic.
One side advantage of this approach is that we can perform more validation
of C++'s operator overloading with built-in candidates vs. the
semantic analysis for those built-in operators: when there are no
viable candidates, we know to expect an error from the built-in
operator handling code. Otherwise, we are not modeling the built-in
semantics properly within operator overloading. This is checked as:
assert(Result.isInvalid() &&
"C++ binary operator overloading is missing
candidates!");
if (Result.isInvalid())
PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
The assert() catches cases where we're wrong in a +Asserts build. The
"if" makes sure that, if this happens in a production clang
(-Asserts), we still build the proper built-in operator and continue
on our merry way. This is effectively what happened before this
change, but we've added the assert() to catch more flies.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83175 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 2f653b5..414525d 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1599,11 +1599,19 @@
}
}
- case OR_No_Viable_Function:
- // No viable function; fall through to handling this as a
- // built-in operator, which will produce an error message for us.
- break;
-
+ case OR_No_Viable_Function: {
+ // No viable function; try checking this as a built-in operator, which
+ // will fail and provide a diagnostic. Then, print the overload
+ // candidates.
+ OwningExprResult Result = CreateBuiltinUnaryOp(OpLoc, Opc, move(Input));
+ assert(Result.isInvalid() &&
+ "C++ postfix-unary operator overloading is missing candidates!");
+ if (Result.isInvalid())
+ PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
+
+ return move(Result);
+ }
+
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
<< UnaryOperator::getOpcodeStr(Opc)
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index aaf76b1..6966926 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -3998,10 +3998,11 @@
Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand)
<< FnType;
- } else {
+ } else if (OnlyViable) {
// FIXME: We need to get the identifier in here
// FIXME: Do we want the error message to point at the operator?
// (built-ins won't have a location)
+ // FIXME: can we get some kind of stable location for this?
QualType FnType
= Context.getFunctionType(Cand->BuiltinTypes.ResultTy,
Cand->BuiltinTypes.ParamTypes,
@@ -4631,19 +4632,34 @@
}
}
- case OR_No_Viable_Function:
+ case OR_No_Viable_Function: {
+ // C++ [over.match.oper]p9:
+ // If the operator is the operator , [...] and there are no
+ // viable functions, then the operator is assumed to be the
+ // built-in operator and interpreted according to clause 5.
+ if (Opc == BinaryOperator::Comma)
+ break;
+
// For class as left operand for assignment or compound assigment operator
// do not fall through to handling in built-in, but report that no overloaded
// assignment operator found
- if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) {
+ OwningExprResult Result = ExprError();
+ if (Args[0]->getType()->isRecordType() &&
+ Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) {
Diag(OpLoc, diag::err_ovl_no_viable_oper)
<< BinaryOperator::getOpcodeStr(Opc)
<< Args[0]->getSourceRange() << Args[1]->getSourceRange();
- return ExprError();
+ } else {
+ // No viable function; try to create a built-in operation, which will
+ // produce an error. Then, show the non-viable candidates.
+ Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
- // No viable function; fall through to handling this as a
- // built-in operator, which will produce an error message for us.
- break;
+ assert(Result.isInvalid() &&
+ "C++ binary operator overloading is missing candidates!");
+ if (Result.isInvalid())
+ PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false);
+ return move(Result);
+ }
case OR_Ambiguous:
Diag(OpLoc, diag::err_ovl_ambiguous_oper)
@@ -4661,9 +4677,7 @@
return ExprError();
}
- // Either we found no viable overloaded operator or we matched a
- // built-in operator. In either case, try to build a built-in
- // operation.
+ // We matched a built-in operator; build it.
return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]);
}
diff --git a/test/SemaCXX/copy-assignment.cpp b/test/SemaCXX/copy-assignment.cpp
index 6e5012f..413e4d1 100644
--- a/test/SemaCXX/copy-assignment.cpp
+++ b/test/SemaCXX/copy-assignment.cpp
@@ -11,7 +11,7 @@
};
struct B {
- B& operator=(B&);
+ B& operator=(B&); // expected-note 4 {{candidate function}}
};
struct ConvertibleToB {
diff --git a/test/SemaCXX/namespace.cpp b/test/SemaCXX/namespace.cpp
index 696ea81..ae8dfc5 100644
--- a/test/SemaCXX/namespace.cpp
+++ b/test/SemaCXX/namespace.cpp
@@ -8,7 +8,8 @@
int A; // expected-error {{redefinition of 'A' as different kind of symbol}}
class A; // expected-error {{redefinition of 'A' as different kind of symbol}}
-class B {}; // expected-note {{previous definition is here}}
+class B {}; // expected-note {{previous definition is here}} \
+ // FIXME: ugly expected-note{{candidate function}}
void C(); // expected-note {{previous definition is here}}
namespace C {} // expected-error {{redefinition of 'C' as different kind of symbol}}
diff --git a/test/SemaCXX/overloaded-builtin-operators.cpp b/test/SemaCXX/overloaded-builtin-operators.cpp
index a8c94f1..0284b29 100644
--- a/test/SemaCXX/overloaded-builtin-operators.cpp
+++ b/test/SemaCXX/overloaded-builtin-operators.cpp
@@ -59,7 +59,7 @@
// FIXME: should pass (void)static_cast<no&>(islong(e1 % e2));
}
-struct ShortRef {
+struct ShortRef { // expected-note{{candidate function}}
operator short&();
};
@@ -67,7 +67,7 @@
operator volatile long&();
};
-struct XpmfRef {
+struct XpmfRef { // expected-note{{candidate function}}
operator pmf&();
};
diff --git a/test/SemaCXX/overloaded-operator.cpp b/test/SemaCXX/overloaded-operator.cpp
index 8471f3c..8f71ad5 100644
--- a/test/SemaCXX/overloaded-operator.cpp
+++ b/test/SemaCXX/overloaded-operator.cpp
@@ -28,12 +28,12 @@
}
struct A {
- bool operator==(Z&); // expected-note{{candidate function}}
+ bool operator==(Z&); // expected-note 2{{candidate function}}
};
A make_A();
-bool operator==(A&, Z&); // expected-note{{candidate function}}
+bool operator==(A&, Z&); // expected-note 2{{candidate function}}
void h(A a, const A ac, Z z) {
make_A() == z;
diff --git a/test/SemaTemplate/qualified-names-diag.cpp b/test/SemaTemplate/qualified-names-diag.cpp
index c875332..1d53e5c 100644
--- a/test/SemaTemplate/qualified-names-diag.cpp
+++ b/test/SemaTemplate/qualified-names-diag.cpp
@@ -1,7 +1,7 @@
// RUN: clang-cc -fsyntax-only -verify %s
namespace std {
- template<typename T> class vector { };
+ template<typename T> class vector { }; // expected-note{{candidate}}
}
typedef int INT;