Revert r107690 (for PR7417) and add a testcase that it breaks. The approach of

that change turns out to not be reasonable: mutating the AST of a parsed
template during instantiation is not a sound thing to do, does not work across
chained PCH / modules builds, and is in any case a special-case workaround to a
more general problem that should be solved centrally.

llvm-svn: 249342

1 files changed, 1 insertions, 42 deletions

diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 88ed127f3b9..7bf1938b86a 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -1804,8 +1804,7 @@ Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
   // unqualified lookup.  This is useful when (for example) the
   // original lookup would not have found something because it was a
   // dependent name.
-  DeclContext *DC = (SS.isEmpty() && !CallsUndergoingInstantiation.empty())
-    ? CurContext : nullptr;
+  DeclContext *DC = SS.isEmpty() ? CurContext : nullptr;
   while (DC) {
     if (isa<CXXRecordDecl>(DC)) {
       LookupQualifiedName(R, DC);
@@ -1833,47 +1832,7 @@ Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
         if (isInstance) {
           Diag(R.getNameLoc(), diagnostic) << Name
             << FixItHint::CreateInsertion(R.getNameLoc(), "this->");
-          UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(
-              CallsUndergoingInstantiation.back()->getCallee());
-
-          CXXMethodDecl *DepMethod;
-          if (CurMethod->isDependentContext()) {
-            DepMethod = CurMethod;
-          } else if (FunctionTemplateDecl *FTD =
-                         CurMethod->getPrimaryTemplate()) {
-            // We have a member function template. It may be contained in a
-            // class template. If so, get the original pattern for the member
-            // function template. Otherwise, 'this' isn't dependent and we can
-            // use CurMethod as is.
-            if (FunctionTemplateDecl *MemberFTD =
-                    FTD->getInstantiatedFromMemberTemplate())
-              DepMethod = cast<CXXMethodDecl>(MemberFTD->getTemplatedDecl());
-            else
-              DepMethod = CurMethod;
-          } else {
-            DepMethod = cast<CXXMethodDecl>(
-                CurMethod->getInstantiatedFromMemberFunction());
-          }
-          assert(DepMethod && "No template pattern found");
-
-          QualType DepThisType = DepMethod->getThisType(Context);
           CheckCXXThisCapture(R.getNameLoc());
-          CXXThisExpr *DepThis = new (Context) CXXThisExpr(
-                                     R.getNameLoc(), DepThisType, false);
-          TemplateArgumentListInfo TList;
-          if (ULE->hasExplicitTemplateArgs())
-            ULE->copyTemplateArgumentsInto(TList);
-
-          CXXScopeSpec SS;
-          SS.Adopt(ULE->getQualifierLoc());
-          CXXDependentScopeMemberExpr *DepExpr =
-              CXXDependentScopeMemberExpr::Create(
-                  Context, DepThis, DepThisType, true, SourceLocation(),
-                  SS.getWithLocInContext(Context),
-                  ULE->getTemplateKeywordLoc(), nullptr,
-                  R.getLookupNameInfo(),
-                  ULE->hasExplicitTemplateArgs() ? &TList : nullptr);
-          CallsUndergoingInstantiation.back()->setCallee(DepExpr);
         } else {
           Diag(R.getNameLoc(), diagnostic) << Name;
         }