[clang] [clang] fix serialization of SubstNonTypeTemplateParmExpr (PR #134560)

[Matheus Izvekov via cfe-commits]

https://github.com/mizvekov created https://github.com/llvm/llvm-project/pull/134560

This fixes a couple of mistakes introduced when merging https://github.com/llvm/llvm-project/pull/132748

Fixes msan failure reported here: https://github.com/llvm/llvm-project/pull/132748#issuecomment-2781105225

>From 0e70eb3b7c8a620977d8468f3443de8e31a97dfa Mon Sep 17 00:00:00 2001
From: Matheus Izvekov <mizvekov at gmail.com>
Date: Sun, 6 Apr 2025 17:06:46 -0300
Subject: [PATCH] [clang] fix serialization of SubstNonTypeTemplateParmExpr

This fixes a couple of mistakes introduced when merging
https://github.com/llvm/llvm-project/pull/132748

Fixes msan failure reported here: https://github.com/llvm/llvm-project/pull/132748#issuecomment-2781105225
---
 clang/lib/AST/ASTContext.cpp              | 2 +-
 clang/lib/Serialization/ASTReaderStmt.cpp | 1 +
 clang/lib/Serialization/ASTWriterStmt.cpp | 1 +
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 1b6b3d06ddc1e..320fd4e2f3077 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -7011,7 +7011,7 @@ TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name,
         getCanonicalTemplateArgument(subst->getArgumentPack());
     return getSubstTemplateTemplateParmPack(
         canonArgPack, subst->getAssociatedDecl()->getCanonicalDecl(),
-        subst->getFinal(), subst->getIndex());
+        subst->getIndex(), subst->getFinal());
   }
   case TemplateName::DeducedTemplate: {
     assert(IgnoreDeduced == false);
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index d26152f3780ed..22fe54b526433 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -2229,6 +2229,7 @@ void ASTStmtReader::VisitSubstNonTypeTemplateParmExpr(
     E->PackIndex = Record.readInt();
   else
     E->PackIndex = 0;
+  E->Final = CurrentUnpackingBits->getNextBit();
   E->SubstNonTypeTemplateParmExprBits.NameLoc = readSourceLocation();
   E->Replacement = Record.readSubExpr();
 }
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 23bb5ff22efaf..d0a0f843c7542 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -2229,6 +2229,7 @@ void ASTStmtWriter::VisitSubstNonTypeTemplateParmExpr(
   CurrentPackingBits.addBit((bool)E->getPackIndex());
   if (auto PackIndex = E->getPackIndex())
     Record.push_back(*PackIndex + 1);
+  CurrentPackingBits.addBit(E->getFinal());
 
   Record.AddSourceLocation(E->getNameLoc());
   Record.AddStmt(E->getReplacement());