[clang] [lld] [llvm] Run ObjCContractPass in Distributed Thin-LTO Pipeline (PR #92331)

[Nuri Amari via llvm-commits]

https://github.com/NuriAmari updated https://github.com/llvm/llvm-project/pull/92331

>From 66ddf609c0e77867ec48c17136fb80d1e482041d Mon Sep 17 00:00:00 2001
From: Nuri Amari <nuriamari at fb.com>
Date: Wed, 15 May 2024 16:33:03 -0700
Subject: [PATCH 1/2] Run ObjCContractPass in Distributed Thin-LTO Pipeline

Prior to this patch, when using -fthinlto-index= the
ObjCARCContractPass isn't run prior to CodeGen, and
instruction selection fails on IR containing
arc intrinstics.
---
 clang/lib/CodeGen/BackendUtil.cpp             |  3 +++
 .../thinlto-distributed-objc-contract-pass.ll | 19 +++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 90985c08fe7f8..03dd1df281d80 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -1289,6 +1289,9 @@ static void runThinLTOBackend(
     };
     break;
   default:
+    Conf.PreCodeGenPassesHook = [](legacy::PassManager &Pm) {
+      Pm.add(createObjCARCContractPass());
+    };
     Conf.CGFileType = getCodeGenFileType(Action);
     break;
   }
diff --git a/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll b/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll
new file mode 100644
index 0000000000000..7d0247555b5c8
--- /dev/null
+++ b/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll
@@ -0,0 +1,19 @@
+; RUN: opt -thinlto-bc -o %t.o %s
+
+; RUN: llvm-lto2 run -thinlto-distributed-indexes %t.o \
+; RUN:   -o %t2.index \
+; RUN:   -r=%t.o,_use_arc,px
+
+; RUN: %clang_cc1 -triple x86_64-apple-darwin \
+; RUN:   -emit-obj -fthinlto-index=%t.o.thinlto.bc \
+; RUN:   -o %t.native.o -x ir %t.o
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-darwin"
+
+define void @use_arc(ptr %a, ptr %b) {
+  call void (...) @llvm.objc.clang.arc.use(i8* %a, i8* %b) nounwind
+  ret void
+}
+
+declare void @llvm.objc.clang.arc.use(...) nounwind

>From 142174dff7b12827f7af187e4ff08b3e75486923 Mon Sep 17 00:00:00 2001
From: Nuri Amari <nuriamari at fb.com>
Date: Fri, 17 May 2024 11:38:16 -0700
Subject: [PATCH 2/2] Address PR Feedback

- Adjust test
- Unconditionally include ARC pass in ThinLTO pipeline
---
 clang/lib/CodeGen/BackendUtil.cpp                            | 3 ---
 clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll | 2 +-
 lld/MachO/LTO.cpp                                            | 3 ---
 llvm/lib/LTO/LTOBackend.cpp                                  | 2 ++
 4 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index 03dd1df281d80..90985c08fe7f8 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -1289,9 +1289,6 @@ static void runThinLTOBackend(
     };
     break;
   default:
-    Conf.PreCodeGenPassesHook = [](legacy::PassManager &Pm) {
-      Pm.add(createObjCARCContractPass());
-    };
     Conf.CGFileType = getCodeGenFileType(Action);
     break;
   }
diff --git a/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll b/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll
index 7d0247555b5c8..a2a7b62cb7f93 100644
--- a/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll
+++ b/clang/test/CodeGen/thinlto-distributed-objc-contract-pass.ll
@@ -12,7 +12,7 @@ target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16
 target triple = "x86_64-apple-darwin"
 
 define void @use_arc(ptr %a, ptr %b) {
-  call void (...) @llvm.objc.clang.arc.use(i8* %a, i8* %b) nounwind
+  call void (...) @llvm.objc.clang.arc.use(ptr %a, ptr %b) nounwind
   ret void
 }
 
diff --git a/lld/MachO/LTO.cpp b/lld/MachO/LTO.cpp
index 7a9a9223a0322..6527cbb68f249 100644
--- a/lld/MachO/LTO.cpp
+++ b/lld/MachO/LTO.cpp
@@ -48,9 +48,6 @@ static lto::Config createConfig() {
   c.CPU = getCPUStr();
   c.MAttrs = getMAttrs();
   c.DiagHandler = diagnosticHandler;
-  c.PreCodeGenPassesHook = [](legacy::PassManager &pm) {
-    pm.add(createObjCARCContractPass());
-  };
 
   c.AlwaysEmitRegularLTOObj = !config->ltoObjPath.empty();
 
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index d4b89ede2d713..aef3a7575dfdf 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -42,6 +42,7 @@
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/TargetParser/SubtargetFeature.h"
 #include "llvm/Transforms/IPO/WholeProgramDevirt.h"
+#include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar/LoopPassManager.h"
 #include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #include "llvm/Transforms/Utils/SplitModule.h"
@@ -415,6 +416,7 @@ static void codegen(const Config &Conf, TargetMachine *TM,
   CodeGenPasses.add(new TargetLibraryInfoWrapperPass(TLII));
   CodeGenPasses.add(
       createImmutableModuleSummaryIndexWrapperPass(&CombinedIndex));
+  CodeGenPasses.add(createObjCARCContractPass());
   if (Conf.PreCodeGenPassesHook)
     Conf.PreCodeGenPassesHook(CodeGenPasses);
   if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS,