r187504 - Improve the diagnostic experience, including adding recovery, for
Kaelyn Uhrain
rikka at google.com
Wed Jul 31 10:38:24 PDT 2013
Author: rikka
Date: Wed Jul 31 12:38:24 2013
New Revision: 187504
URL: http://llvm.org/viewvc/llvm-project?rev=187504&view=rev
Log:
Improve the diagnostic experience, including adding recovery, for
changing '->' to '.' when there is no operator-> defined for a class.
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaExprMember.cpp
cfe/trunk/lib/Sema/SemaOverload.cpp
cfe/trunk/test/SemaCXX/member-expr.cpp
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Wed Jul 31 12:38:24 2013
@@ -4233,6 +4233,8 @@ def err_typecheck_member_reference_sugge
"member reference type %0 is %select{a|not a}1 pointer; maybe you meant to use '%select{->|.}1'?">;
def note_typecheck_member_reference_suggestion : Note<
"did you mean to use '.' instead?">;
+def note_member_reference_arrow_from_operator_arrow : Note<
+ "'->' applied to return value of the operator->() declared here">;
def err_typecheck_member_reference_type : Error<
"cannot refer to type member %0 in %1 with '%select{.|->}2'">;
def err_typecheck_member_reference_unknown : Error<
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Wed Jul 31 12:38:24 2013
@@ -2256,7 +2256,8 @@ public:
SourceLocation RParenLoc);
ExprResult BuildOverloadedArrowExpr(Scope *S, Expr *Base,
- SourceLocation OpLoc);
+ SourceLocation OpLoc,
+ bool *NoArrowOperatorFound = 0);
/// CheckCallReturnType - Checks that a call expression's return type is
/// complete. Returns true on failure. The location passed in is the location
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Wed Jul 31 12:38:24 2013
@@ -5076,15 +5076,44 @@ Sema::ActOnStartCXXMemberReference(Scope
// [...] When operator->returns, the operator-> is applied to the value
// returned, with the original second operand.
if (OpKind == tok::arrow) {
+ bool NoArrowOperatorFound = false;
+ bool FirstIteration = true;
+ FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext);
// The set of types we've considered so far.
llvm::SmallPtrSet<CanQualType,8> CTypes;
SmallVector<SourceLocation, 8> Locations;
CTypes.insert(Context.getCanonicalType(BaseType));
while (BaseType->isRecordType()) {
- Result = BuildOverloadedArrowExpr(S, Base, OpLoc);
- if (Result.isInvalid())
+ Result = BuildOverloadedArrowExpr(
+ S, Base, OpLoc,
+ // When in a template specialization and on the first loop iteration,
+ // potentially give the default diagnostic (with the fixit in a
+ // separate note) instead of having the error reported back to here
+ // and giving a diagnostic with a fixit attached to the error itself.
+ (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization())
+ ? 0
+ : &NoArrowOperatorFound);
+ if (Result.isInvalid()) {
+ if (NoArrowOperatorFound) {
+ if (FirstIteration) {
+ Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
+ << BaseType << 1 << Base->getSourceRange()
+ << FixItHint::CreateReplacement(OpLoc, ".");
+ OpKind = tok::period;
+ break;
+ } else {
+ Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
+ << BaseType << Base->getSourceRange();
+ CallExpr *CE = dyn_cast<CallExpr>(Base);
+ if (Decl *CD = (CE ? CE->getCalleeDecl() : 0)) {
+ Diag(CD->getLocStart(),
+ diag::note_member_reference_arrow_from_operator_arrow);
+ }
+ }
+ }
return ExprError();
+ }
Base = Result.get();
if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base))
Locations.push_back(OpCall->getDirectCallee()->getLocation());
@@ -5096,9 +5125,11 @@ Sema::ActOnStartCXXMemberReference(Scope
Diag(Locations[i], diag::note_declared_at);
return ExprError();
}
+ FirstIteration = false;
}
- if (BaseType->isPointerType() || BaseType->isObjCObjectPointerType())
+ if (OpKind == tok::arrow &&
+ (BaseType->isPointerType() || BaseType->isObjCObjectPointerType()))
BaseType = BaseType->getPointeeType();
}
Modified: cfe/trunk/lib/Sema/SemaExprMember.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprMember.cpp?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprMember.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprMember.cpp Wed Jul 31 12:38:24 2013
@@ -1136,10 +1136,8 @@ Sema::LookupMemberExpr(LookupResult &R,
// foo->bar
// This is actually well-formed in C++ if MyRecord has an
// overloaded operator->, but that should have been dealt with
- // by now.
- Diag(OpLoc, diag::err_typecheck_member_reference_suggestion)
- << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange()
- << FixItHint::CreateReplacement(OpLoc, ".");
+ // by now--or a diagnostic message already issued if a problem
+ // was encountered while looking for the overloaded operator->.
IsArrow = false;
} else if (BaseType->isFunctionType()) {
goto fail;
Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Wed Jul 31 12:38:24 2013
@@ -11463,7 +11463,8 @@ Sema::BuildCallToObjectOfClassType(Scope
/// (if one exists), where @c Base is an expression of class type and
/// @c Member is the name of the member we're trying to find.
ExprResult
-Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) {
+Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc,
+ bool *NoArrowOperatorFound) {
assert(Base->getType()->isRecordType() &&
"left-hand side must have class type");
@@ -11509,6 +11510,12 @@ Sema::BuildOverloadedArrowExpr(Scope *S,
case OR_No_Viable_Function:
if (CandidateSet.empty()) {
QualType BaseType = Base->getType();
+ if (NoArrowOperatorFound) {
+ // Report this specific error to the caller instead of emitting a
+ // diagnostic, as requested.
+ *NoArrowOperatorFound = true;
+ return ExprError();
+ }
Diag(OpLoc, diag::err_typecheck_member_reference_arrow)
<< BaseType << Base->getSourceRange();
if (BaseType->isRecordType() && !BaseType->isPointerType()) {
Modified: cfe/trunk/test/SemaCXX/member-expr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/member-expr.cpp?rev=187504&r1=187503&r2=187504&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/member-expr.cpp (original)
+++ cfe/trunk/test/SemaCXX/member-expr.cpp Wed Jul 31 12:38:24 2013
@@ -79,16 +79,13 @@ namespace test5 {
};
void test0(int x) {
- x.A::foo<int>(); // expected-error {{'int' is not a structure or union}}
}
void test1(A *x) {
- x.A::foo<int>(); // expected-error {{'test5::A *' is a pointer}}
}
void test2(A &x) {
- x->A::foo<int>(); // expected-error {{'test5::A' is not a pointer}} \
- // expected-note {{did you mean to use '.' instead?}}
+ x->A::foo<int>(); // expected-error {{'test5::A' is not a pointer; maybe you meant to use '.'?}}
}
}
@@ -182,7 +179,36 @@ namespace PR15045 {
int f() {
Cl0 c;
- return c->a; // expected-error {{member reference type 'PR15045::Cl0' is not a pointer}} \
- // expected-note {{did you mean to use '.' instead?}}
+ return c->a; // expected-error {{member reference type 'PR15045::Cl0' is not a pointer; maybe you meant to use '.'?}}
+ }
+
+ struct bar {
+ void func(); // expected-note {{'func' declared here}}
+ };
+
+ struct foo {
+ bar operator->(); // expected-note 2 {{'->' applied to return value of the operator->() declared here}}
+ };
+
+ template <class T> void call_func(T t) {
+ t->func(); // expected-error-re 2 {{member reference type 'PR15045::bar' is not a pointer$}} \
+ // expected-note {{did you mean to use '.' instead?}}
+ }
+
+ void test_arrow_on_non_pointer_records() {
+ bar e;
+ foo f;
+
+ // Show that recovery has happened by also triggering typo correction
+ e->Func(); // expected-error {{member reference type 'PR15045::bar' is not a pointer; maybe you meant to use '.'?}} \
+ // expected-error {{no member named 'Func' in 'PR15045::bar'; did you mean 'func'?}}
+
+ // Make sure a fixit isn't given in the case that the '->' isn't actually
+ // the problem (the problem is with the return value of an operator->).
+ f->func(); // expected-error-re {{member reference type 'PR15045::bar' is not a pointer$}}
+
+ call_func(e); // expected-note {{in instantiation of function template specialization 'PR15045::call_func<PR15045::bar>' requested here}}
+
+ call_func(f); // expected-note {{in instantiation of function template specialization 'PR15045::call_func<PR15045::foo>' requested here}}
}
}
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