From 7cba1f9eab463738f6b3530597cae76cd8bc4dc0 Mon Sep 17 00:00:00 2001
From: Krasimir Georgiev <krasimir@google.com>
Date: Tue, 16 Aug 2022 13:02:45 +0000
Subject: [PATCH] llvm-wrapper: use new pass manager for thin lto with LLVM
 version 15

No functional changes intended.

LLVM commit https://github.com/llvm/llvm-project/commit/633f5663c37a670e28040cadd938200abd854483 removed `createWriteThinLTOBitcodePass`.
This adapts PassWrapper similarly to the example mentioned upstream: https://github.com/llvm/llvm-project/commit/633f5663c37a670e28040cadd938200abd854483.
---
 .../rustc_llvm/llvm-wrapper/PassWrapper.cpp   | 25 +++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index b4314223722fc..05d2a214d0b79 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -31,6 +31,9 @@
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
+#if LLVM_VERSION_GE(15, 0)
+#include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
+#endif
 #include "llvm/Transforms/Utils/AddDiscriminators.h"
 #include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #include "llvm/LTO/LTO.h"
@@ -1587,13 +1590,31 @@ LLVMRustThinLTOBufferCreate(LLVMModuleRef M, bool is_thin) {
   {
     raw_string_ostream OS(Ret->data);
     {
-      legacy::PassManager PM;
       if (is_thin) {
+#if LLVM_VERSION_LT(15, 0)
+        legacy::PassManager PM;
         PM.add(createWriteThinLTOBitcodePass(OS));
+        PM.run(*unwrap(M));
+#else
+        PassBuilder PB;
+        LoopAnalysisManager LAM;
+        FunctionAnalysisManager FAM;
+        CGSCCAnalysisManager CGAM;
+        ModuleAnalysisManager MAM;
+        PB.registerModuleAnalyses(MAM);
+        PB.registerCGSCCAnalyses(CGAM);
+        PB.registerFunctionAnalyses(FAM);
+        PB.registerLoopAnalyses(LAM);
+        PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
+        ModulePassManager MPM;
+        MPM.addPass(ThinLTOBitcodeWriterPass(OS, nullptr));
+        MPM.run(*unwrap(M), MAM);
+#endif
       } else {
+        legacy::PassManager PM;
         PM.add(createBitcodeWriterPass(OS));
+        PM.run(*unwrap(M));
       }
-      PM.run(*unwrap(M));
     }
   }
   return Ret.release();