[clang] [Clang][Modules] Fix -Wunused-variable (PR #196577)

[Aiden Grossman via cfe-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/196577

Mark some variables [[maybe_unused]] and inline others that do not have
side effects to avoid -Wunused-variable in non-assert builds.

>From bcc884511c67b540a631f9c0e5a2d7b05e54cf31 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Fri, 8 May 2026 16:52:24 +0000
Subject: [PATCH] [Clang][Modules] Fix -Wunused-variable

Mark some variables [[maybe_unused]] and inline others that do not have
side effects to avoid -Wunused-variable in non-assert builds.
---
 clang/lib/Serialization/ASTReader.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 6b242f553c59d..dfd714dd53814 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -6327,7 +6327,8 @@ Module *ASTReader::getSubmodule(uint32_t GlobalID) {
   assert(It != GlobalSubmoduleMap.end());
   ModuleFile &F = *It->second;
   unsigned Index = GlobalID - F.BaseSubmoduleID - NUM_PREDEF_SUBMODULE_IDS;
-  unsigned LocalID = Index + F.LocalBaseSubmoduleID + NUM_PREDEF_SUBMODULE_IDS;
+  [[maybe_unused]] unsigned LocalID =
+      Index + F.LocalBaseSubmoduleID + NUM_PREDEF_SUBMODULE_IDS;
 
   BitstreamCursor &Cursor = F.SubmodulesCursor;
   SavedStreamPosition SavedPosition(Cursor);
@@ -6397,10 +6398,9 @@ Module *ASTReader::getSubmodule(uint32_t GlobalID) {
 
       StringRef Name = Blob;
       unsigned Idx = 0;
-      unsigned ReadLocalID = Record[Idx++];
+      [[maybe_unused]] unsigned ReadLocalID = Record[Idx++];
       assert(LocalID == ReadLocalID);
-      SubmoduleID ReadGlobalID = getGlobalSubmoduleID(F, ReadLocalID);
-      assert(GlobalID == ReadGlobalID);
+      assert(GlobalID == getGlobalSubmoduleID(F, ReadLocalID));
       SubmoduleID Parent = getGlobalSubmoduleID(F, Record[Idx++]);
       Module::ModuleKind Kind = (Module::ModuleKind)Record[Idx++];
       SourceLocation DefinitionLoc = ReadSourceLocation(F, Record[Idx++]);