test various nested templated contexts and fix bugs

Author: hnrklssn

clang/lib/Sema/DynamicCountPointerAssignmentAnalysis.cpp

@@ -3484,8 +3484,8 @@ namespace clang {
 
 void DynamicCountPointerAssignmentAnalysis::run() {
   AnalysisDeclContext AC(/* AnalysisDeclContextManager */ nullptr, dcl);
-  if (isa<TemplateDecl>(dcl)) // delay processing until template has been
-                              // instantiated
+  if (dcl->isTemplated()) // delay processing until template has been
+                          // instantiated
     return;
 
   CFG *cfg = AC.getCFG();

clang/lib/Sema/SemaDecl.cpp

@@ -17302,6 +17302,11 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
     // the declaration context below. Otherwise, we're unable to transform
     // 'this' expressions when transforming immediate context functions.
 
+  /*TO_UPSTREAM(BoundsSafety) ON*/
+  if (LangOpts.BoundsSafety)
+    DynamicCountPointerAssignmentAnalysis(*this, dcl).run();
+  /*TO_UPSTREAM(BoundsSafety) OFF*/
+
   if (!IsInstantiation)
     PopDeclContext();
 
@@ -17325,11 +17330,6 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
   if (FD && !FD->isDeleted())
     checkTypeSupport(FD->getType(), FD->getLocation(), FD);
 
-  /*TO_UPSTREAM(BoundsSafety) ON*/
-  if (LangOpts.BoundsSafety)
-    DynamicCountPointerAssignmentAnalysis(*this, dcl).run();
-  /*TO_UPSTREAM(BoundsSafety) OFF*/
-
   return dcl;
 }
 

clang/lib/Sema/SemaDeclAttr.cpp

@@ -6751,7 +6751,7 @@ static void handlePtrCountedByEndedByAttr(Sema &S, Decl *D,
   if (!S.checkUInt32Argument(AL, AL.getArgAsExpr(1), Level))
     return;
 
-  if (D->getDescribedTemplate() || S.CurContext->isDependentContext()) {
+  if (D->isTemplated()) {
     DynamicBoundsAttrInfo Info(D, Level);
     // Scope information will be invalid by the time we instantiate the
     // template, so perform these checks now and delay the rest of the

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -674,6 +674,20 @@ instantiateBoundsSafetyAttr(Sema &S,
   } else
     llvm_unreachable("unexpected late instantiated bounds safety attribute");
 
+  DeclContext *DC;
+  if (auto *FD = dyn_cast<FunctionDecl>(New)) {
+    DC = FD; // make sure we can refer to parameters in attribute
+  } else {
+    DC = New->getDeclContext();
+  }
+  Sema::ContextRAII SetContext(S, DC);
+  if (auto *RD = dyn_cast<CXXRecordDecl>(DC)) {
+    // Set `this` type as if we were in a decl scope lambda
+    // It's reset along with CurContext when SetContext goes out of scope
+    QualType ClassTy = S.Context.getTypeDeclType(RD);
+    S.CXXThisTypeOverride = S.Context.getPointerType(ClassTy);
+  }
+
   ExprResult InstantiatedArgExpr = S.SubstExpr(ArgExpr, TemplateArgs);
   if (InstantiatedArgExpr.isInvalid())
     return;