From 472fef6a70d6621611a20f13f02c16be93589f5c Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@google.com>
Date: Mon, 16 Sep 2024 17:11:02 -0700
Subject: [PATCH] Revert "Rollup merge of #129749 - krasimirgg:llvm-20-lto,
 r=nikic"

This reverts commit 8c7a7e346be4cdf13e77ab4acbfb5ade819a4e60, reversing
changes made to a00bd75b6c5c96d0a35afa2dc07ce3155112d278.
---
 compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index da27db29c87..c7306b0516f 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -1212,11 +1212,7 @@ struct LLVMRustThinLTOData {
   // Not 100% sure what these are, but they impact what's internalized and
   // what's inlined across modules, I believe.
 #if LLVM_VERSION_GE(18, 0)
-#if LLVM_VERSION_GE(20, 0)
-  FunctionImporter::ImportListsTy ImportLists;
-#else
   DenseMap<StringRef, FunctionImporter::ImportMapTy> ImportLists;
-#endif
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists;
   DenseMap<StringRef, GVSummaryMapTy> ModuleToDefinedGVSummaries;
 #else
@@ -1425,13 +1421,13 @@ LLVMRustPrepareThinLTOInternalize(const LLVMRustThinLTOData *Data,
   return true;
 }
 
-extern "C" bool LLVMRustPrepareThinLTOImport(LLVMRustThinLTOData *Data,
+extern "C" bool LLVMRustPrepareThinLTOImport(const LLVMRustThinLTOData *Data,
                                              LLVMModuleRef M,
                                              LLVMTargetMachineRef TM) {
   Module &Mod = *unwrap(M);
   TargetMachine &Target = *unwrap(TM);
 
-  const auto &ImportList = Data->ImportLists[Mod.getModuleIdentifier()];
+  const auto &ImportList = Data->ImportLists.lookup(Mod.getModuleIdentifier());
   auto Loader = [&](StringRef Identifier) {
     const auto &Memory = Data->ModuleMap.lookup(Identifier);
     auto &Context = Mod.getContext();
@@ -1614,7 +1610,7 @@ extern "C" void LLVMRustComputeLTOCacheKey(RustStringRef KeyOut,
                                            LLVMRustThinLTOData *Data) {
   SmallString<40> Key;
   llvm::lto::Config conf;
-  const auto &ImportList = Data->ImportLists[ModId];
+  const auto &ImportList = Data->ImportLists.lookup(ModId);
   const auto &ExportList = Data->ExportLists.lookup(ModId);
   const auto &ResolvedODR = Data->ResolvedODR.lookup(ModId);
   const auto &DefinedGlobals = Data->ModuleToDefinedGVSummaries.lookup(ModId);