git: d7d2f810f8a9 - stable/12 - Apply clang fix for assertion failure compiling multimedia/minitube

[Dimitry Andric]

The branch stable/12 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=d7d2f810f8a9a21282803bf886705656f1af26c3

commit d7d2f810f8a9a21282803bf886705656f1af26c3
Author:     Dimitry Andric <dim at FreeBSD.org>
AuthorDate: 2021-08-21 21:03:37 +0000
Commit:     Dimitry Andric <dim at FreeBSD.org>
CommitDate: 2021-08-26 18:05:13 +0000

    Apply clang fix for assertion failure compiling multimedia/minitube
    
    Merge commit 79f9cfbc21e0 from llvm git (by Yaxun (Sam) Liu):
    
      Do not merge LocalInstantiationScope for template specialization
    
      A lambda in a function template may be recursively instantiated. The recursive
      lambda will cause a lambda function instantiated multiple times, one inside another.
      The inner LocalInstantiationScope should not be marked as MergeWithParentScope
      since it already has references to locals properly substituted, otherwise it causes
      assertion due to the check for duplicate locals in merged LocalInstantiationScope.
    
      Reviewed by: Richard Smith
    
      Differential Revision: https://reviews.llvm.org/D98068
    
    Reported by:    yuri
    PR:             257978
    
    (cherry picked from commit efa485d5c390b745f53761da9159721243c48b7b)
---
 .../llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp    | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/contrib/llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/contrib/llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index f801e79c8902..f36fa8d11b3b 100644
--- a/contrib/llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/contrib/llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -4658,10 +4658,13 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   // Introduce a new scope where local variable instantiations will be
   // recorded, unless we're actually a member function within a local
   // class, in which case we need to merge our results with the parent
-  // scope (of the enclosing function).
+  // scope (of the enclosing function). The exception is instantiating
+  // a function template specialization, since the template to be
+  // instantiated already has references to locals properly substituted.
   bool MergeWithParentScope = false;
   if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
-    MergeWithParentScope = Rec->isLocalClass();
+    MergeWithParentScope =
+        Rec->isLocalClass() && !Function->isFunctionTemplateSpecialization();
 
   LocalInstantiationScope Scope(*this, MergeWithParentScope);