reapply my patch for PR4451, which improves diagnostics for :: vs : confusion.
This time with a fix to bail out when in a dependent context.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90730 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp
index 14db774..3c5dd54 100644
--- a/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/lib/Sema/SemaCXXScopeSpec.cpp
@@ -330,6 +330,12 @@
/// that it contains an extra parameter \p ScopeLookupResult, which provides
/// the result of name lookup within the scope of the nested-name-specifier
/// that was computed at template definitino time.
+///
+/// If ErrorRecoveryLookup is true, then this call is used to improve error
+/// recovery. This means that it should not emit diagnostics, it should
+/// just return null on failure. It also means it should only return a valid
+/// scope if it *knows* that the result is correct. It should not return in a
+/// dependent context, for example.
Sema::CXXScopeTy *Sema::BuildCXXNestedNameSpecifier(Scope *S,
const CXXScopeSpec &SS,
SourceLocation IdLoc,
@@ -337,7 +343,8 @@
IdentifierInfo &II,
QualType ObjectType,
NamedDecl *ScopeLookupResult,
- bool EnteringContext) {
+ bool EnteringContext,
+ bool ErrorRecoveryLookup) {
NestedNameSpecifier *Prefix
= static_cast<NestedNameSpecifier *>(SS.getScopeRep());
@@ -403,6 +410,10 @@
ObjectTypeSearchedInScope = true;
}
} else if (isDependent) {
+ // Don't speculate if we're just trying to improve error recovery.
+ if (ErrorRecoveryLookup)
+ return 0;
+
// We were not able to compute the declaration context for a dependent
// base object type or prior nested-name-specifier, so this
// nested-name-specifier refers to an unknown specialization. Just build
@@ -442,14 +453,17 @@
!Context.hasSameType(
Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
+ if (ErrorRecoveryLookup)
+ return 0;
+
Diag(IdLoc, diag::err_nested_name_member_ref_lookup_ambiguous)
<< &II;
Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
<< ObjectType;
Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
- // Fall through so that we'll pick the name we found in the object type,
- // since that's probably what the user wanted anyway.
+ // Fall through so that we'll pick the name we found in the object
+ // type, since that's probably what the user wanted anyway.
}
}
@@ -469,6 +483,11 @@
T.getTypePtr());
}
+ // Otherwise, we have an error case. If we don't want diagnostics, just
+ // return an error now.
+ if (ErrorRecoveryLookup)
+ return 0;
+
// If we didn't find anything during our lookup, try again with
// ordinary name lookup, which can help us produce better error
// messages.
@@ -509,7 +528,23 @@
bool EnteringContext) {
return BuildCXXNestedNameSpecifier(S, SS, IdLoc, CCLoc, II,
QualType::getFromOpaquePtr(ObjectTypePtr),
- /*ScopeLookupResult=*/0, EnteringContext);
+ /*ScopeLookupResult=*/0, EnteringContext,
+ false);
+}
+
+/// IsInvalidUnlessNestedName - This method is used for error recovery
+/// purposes to determine whether the specified identifier is only valid as
+/// a nested name specifier, for example a namespace name. It is
+/// conservatively correct to always return false from this method.
+///
+/// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier.
+bool Sema::IsInvalidUnlessNestedName(Scope *S, const CXXScopeSpec &SS,
+ IdentifierInfo &II, TypeTy *ObjectType,
+ bool EnteringContext) {
+ return BuildCXXNestedNameSpecifier(S, SS, SourceLocation(), SourceLocation(),
+ II, QualType::getFromOpaquePtr(ObjectType),
+ /*ScopeLookupResult=*/0, EnteringContext,
+ true);
}
Sema::CXXScopeTy *Sema::ActOnCXXNestedNameSpecifier(Scope *S,