From 6c596be66539299d553c77acf94db2bed63a6fc5 Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Mon, 5 Feb 2024 10:16:17 +0100
Subject: [PATCH] Merge commit 5f4ee5a2dfa9 from llvm-project (by Shanzhi):

  [Clang][AST] Fix a crash on attaching doc comments (#78716)

  This crash is basically caused by calling
  `ASTContext::getRawCommentForDeclNoCacheImp` with its input arguments
  `RepresentativeLocForDecl` and `CommentsInTheFile` refering to different
  files. A reduced reproducer is provided in this patch.

  After the source locations for instantiations of funtion template are
  corrected in the commit 256a0b298c68b89688b80350b034daf2f7785b67, the
  variable `CommitsInThisFile` in the function
  `ASTContext::attachCommentsToJustParsedDecls` would refer to the source
  file rather than the header file for implicit function template
  instantiation. Therefore, in the first loop in
  `ASTContext::attachCommentsToJustParsedDecls`, `D` should also be
  adjusted for relevant scenarios like the second loop.

  Fixes #67979
  Fixes #68524
  Fixes #70550

This should fix a segfault when compiling graphics/gdal.

PR:		276104
MFC after:	1 month

(cherry picked from commit dc36515b628331e03ac8c23a6749f7f3eb1ebec8)
---
 contrib/llvm-project/clang/lib/AST/ASTContext.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/contrib/llvm-project/clang/lib/AST/ASTContext.cpp b/contrib/llvm-project/clang/lib/AST/ASTContext.cpp
index 5eb7aa366456..9a0ede201059 100644
--- a/contrib/llvm-project/clang/lib/AST/ASTContext.cpp
+++ b/contrib/llvm-project/clang/lib/AST/ASTContext.cpp
@@ -498,7 +498,11 @@ void ASTContext::attachCommentsToJustParsedDecls(ArrayRef<Decl *> Decls,
     return;
 
   FileID File;
-  for (Decl *D : Decls) {
+  for (const Decl *D : Decls) {
+    if (D->isInvalidDecl())
+      continue;
+
+    D = &adjustDeclToTemplate(*D);
     SourceLocation Loc = D->getLocation();
     if (Loc.isValid()) {
       // See if there are any new comments that are not attached to a decl.