ms-compat: Fix taking the address of a member of a dependent base
If unqualified id lookup fails while parsing a class template with a
dependent base, clang with -fms-compatibility will pretend the user
prefixed the name with 'this->' in order to delay the lookup. However,
if there was a unary ampersand, Sema::ActOnDependentIdExpression() will
create a DependentDeclRefExpr, which is not what we wanted at all. Fix
this by building the CXXDependentScopeMemberExpr directly instead.
In order to be fully MSVC compatible, we would have to defer all
attempts at name lookup to instantiation time. However, until we have
real problems with system headers that can't be parsed, we'll put off
implementing that.
Fixes PR16014.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1892
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192727 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 04e01f6..1405903 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2020,14 +2020,26 @@
if (R.empty()) {
// In Microsoft mode, if we are inside a template class member function
// whose parent class has dependent base classes, and we can't resolve
- // an identifier, then assume the identifier is type dependent. The
- // goal is to postpone name lookup to instantiation time to be able to
- // search into the type dependent base classes.
+ // an identifier, then assume the identifier is a member of a dependent
+ // base class. The goal is to postpone name lookup to instantiation time
+ // to be able to search into the type dependent base classes.
+ // FIXME: If we want 100% compatibility with MSVC, we will have delay all
+ // unqualified name lookup. Any name lookup during template parsing means
+ // clang might find something that MSVC doesn't. For now, we only handle
+ // the common case of members of a dependent base class.
if (getLangOpts().MicrosoftMode) {
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(CurContext);
- if (MD && MD->getParent()->hasAnyDependentBases())
- return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo,
- IsAddressOfOperand, TemplateArgs);
+ if (MD && MD->isInstance() && MD->getParent()->hasAnyDependentBases()) {
+ assert(SS.isEmpty() && "qualifiers should be already handled");
+ QualType ThisType = MD->getThisType(Context);
+ // Since the 'this' expression is synthesized, we don't need to
+ // perform the double-lookup check.
+ NamedDecl *FirstQualifierInScope = 0;
+ return Owned(CXXDependentScopeMemberExpr::Create(
+ Context, /*This=*/0, ThisType, /*IsArrow=*/true,
+ /*Op=*/SourceLocation(), SS.getWithLocInContext(Context),
+ TemplateKWLoc, FirstQualifierInScope, NameInfo, TemplateArgs));
+ }
}
// Don't diagnose an empty lookup for inline assmebly.
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 6f5f72e..97e12d7 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -8109,6 +8109,7 @@
TreeTransform<Derived>::TransformDependentScopeDeclRefExpr(
DependentScopeDeclRefExpr *E,
bool IsAddressOfOperand) {
+ assert(E->getQualifierLoc());
NestedNameSpecifierLoc QualifierLoc
= getDerived().TransformNestedNameSpecifierLoc(E->getQualifierLoc());
if (!QualifierLoc)