Speculatively revert r110610 " Make ObjCInterfaceDecl redeclarable,

and create separate decl nodes for forward declarations and the
definition," which appears to be causing significant Objective-C
breakage.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110803 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index d94b8dd304..47eb3eec89 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -606,6 +606,45 @@ void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
   }
 }
 
+/// \brief Look for an Objective-C class in the translation unit.
+///
+/// \param Id The name of the Objective-C class we're looking for. If
+/// typo-correction fixes this name, the Id will be updated
+/// to the fixed name.
+///
+/// \param IdLoc The location of the name in the translation unit.
+///
+/// \param TypoCorrection If true, this routine will attempt typo correction
+/// if there is no class with the given name.
+///
+/// \returns The declaration of the named Objective-C class, or NULL if the
+/// class could not be found.
+ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id,
+                                              SourceLocation IdLoc,
+                                              bool TypoCorrection) {
+  // The third "scope" argument is 0 since we aren't enabling lazy built-in
+  // creation from this context.
+  NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName);
+
+  if (!IDecl && TypoCorrection) {
+    // Perform typo correction at the given location, but only if we
+    // find an Objective-C class name.
+    LookupResult R(*this, Id, IdLoc, LookupOrdinaryName);
+    if (CorrectTypo(R, TUScope, 0, 0, false, CTC_NoKeywords) &&
+        (IDecl = R.getAsSingle<ObjCInterfaceDecl>())) {
+      Diag(IdLoc, diag::err_undef_interface_suggest)
+        << Id << IDecl->getDeclName() 
+        << FixItHint::CreateReplacement(IdLoc, IDecl->getNameAsString());
+      Diag(IDecl->getLocation(), diag::note_previous_decl)
+        << IDecl->getDeclName();
+      
+      Id = IDecl->getIdentifier();
+    }
+  }
+
+  return dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
+}
+
 /// getNonFieldDeclScope - Retrieves the innermost scope, starting
 /// from S, where a non-field would be declared. This routine copes
 /// with the difference between C and C++ scoping rules in structs and