Teach TreeTransform and family how to transform generic lambdas within templates and nested within themselves.

  
This does not yet include capturing (that is next).

Please see test file for examples.

This patch was LGTM'd by Doug:
http://llvm-reviews.chandlerc.com/D1784

llvm-svn: 191875

1 files changed, 24 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 35f3616db6a..359fb73166d 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4171,6 +4171,30 @@ DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
                           const MultiLevelTemplateArgumentList &TemplateArgs) {
   DeclContext *ParentDC = D->getDeclContext();
+
+  // If we have a parameter from a non-dependent context with a non-dependent
+  // type it obviously can not be mapped to a different instantiated decl.
+  // Consider the code below, with explicit return types, when N gets
+  // specialized ...:
+  // template<class T> void fooT(T t) {
+  //   auto L = [](auto a) -> void { 
+  //     auto M = [](char b) -> void {
+  //       auto N = [](auto c) -> void {
+  //         int x = sizeof(a) + sizeof(b) +
+  //                 sizeof(c);
+  //       };  
+  //       N('a');
+  //     };    
+  //   };
+  //   L(3.14);
+  // }
+  // fooT('a'); 
+  // ... without this check below, findInstantiationOf fails with
+  // an assertion violation.
+  if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
+      !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
+    return D;
+
   if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
       isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
       (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||