1 files changed, 9 insertions, 0 deletions
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index e6812ac..96c25ba 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -6987,6 +6987,15 @@ void Parser::ParseFunctionDeclarator(Declarator &D,
         continue;
       DeclsInPrototype.push_back(ND);
     }
+    // Sort DeclsInPrototype based on raw encoding of the source location.
+    // Scope::decls() is iterating over a SmallPtrSet so sort the Decls before
+    // moving to DeclContext. This provides a stable ordering for traversing
+    // Decls in DeclContext, which is important for tasks like ASTWriter for
+    // deterministic output.
+    llvm::sort(DeclsInPrototype, [](Decl *D1, Decl *D2) {
+      return D1->getLocation().getRawEncoding() <
+             D2->getLocation().getRawEncoding();
+    });
   }
 
   // Remember that we parsed a function type, and remember the attributes.