From 596d9853bb6c44c3ae290a40f792ee4ec54d1ea0 Mon Sep 17 00:00:00 2001
From: Devon Loehr <dloehr@google.com>
Date: Mon, 4 May 2026 17:41:27 +0000
Subject: [PATCH] Adjust getMCSubtargetInfo signature for LLVM 23+

---
 .../rustc_llvm/llvm-wrapper/PassWrapper.cpp   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index c7e8f99465e1..643e4944bf78 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -91,8 +91,13 @@ extern "C" void LLVMRustTimeTraceProfilerFinish(const char *FileName) {
 extern "C" bool LLVMRustHasFeature(LLVMTargetMachineRef TM,
                                    const char *Feature) {
   TargetMachine *Target = unwrap(TM);
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+  return MCInfo.checkFeatures(std::string("+") + Feature);
+#else
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   return MCInfo->checkFeatures(std::string("+") + Feature);
+#endif
 }
 
 /// Check whether the target has a specific assembly mnemonic like `ret` or
@@ -274,7 +279,11 @@ static llvm::DebugCompressionType fromRust(LLVMRustCompressionKind Kind) {
 extern "C" void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef TM,
                                         RustStringRef OutStr) {
   ArrayRef<SubtargetSubTypeKV> CPUTable =
+#if LLVM_VERSION_GE(23, 0)
+      unwrap(TM)->getMCSubtargetInfo().getAllProcessorDescriptions();
+#else
       unwrap(TM)->getMCSubtargetInfo()->getAllProcessorDescriptions();
+#endif
   auto OS = RawRustStringOstream(OutStr);
 
   // Just print a bare list of target CPU names, and let Rust-side code handle
@@ -286,9 +295,15 @@ extern "C" void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef TM,
 
 extern "C" size_t LLVMRustGetTargetFeaturesCount(LLVMTargetMachineRef TM) {
   const TargetMachine *Target = unwrap(TM);
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+  const ArrayRef<SubtargetFeatureKV> FeatTable =
+      MCInfo.getAllProcessorFeatures();
+#else
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
       MCInfo->getAllProcessorFeatures();
+#endif
   return FeatTable.size();
 }
 
@@ -296,9 +311,15 @@ extern "C" void LLVMRustGetTargetFeature(LLVMTargetMachineRef TM, size_t Index,
                                          const char **Feature,
                                          const char **Desc) {
   const TargetMachine *Target = unwrap(TM);
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+  const ArrayRef<SubtargetFeatureKV> FeatTable =
+      MCInfo.getAllProcessorFeatures();
+#else
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
       MCInfo->getAllProcessorFeatures();
+#endif
   const SubtargetFeatureKV Feat = FeatTable[Index];
   *Feature = Feat.Key;
   *Desc = Feat.Desc;