Rollup merge of #156156 - DKLoehr:subtarget_info, r=cuviper

Adjust getMCSubtargetInfo signature for LLVM 23+

A recent [LLVM PR](llvm/llvm-project#195032) changed the signature of `getMCSubtargetInfo` to return a reference instead of a pointer. This adjusts uses of the function in `compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp` to account for the different signature.

Author: jhpratt

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -91,8 +91,12 @@ extern "C" void LLVMRustTimeTraceProfilerFinish(const char *FileName) {
 extern "C" bool LLVMRustHasFeature(LLVMTargetMachineRef TM,
                                    const char *Feature) {
   TargetMachine *Target = unwrap(TM);
-  const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
-  return MCInfo->checkFeatures(std::string("+") + Feature);
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+#else
+  const MCSubtargetInfo &MCInfo = *Target->getMCSubtargetInfo();
+#endif
+  return MCInfo.checkFeatures(std::string("+") + Feature);
 }
 
 /// Check whether the target has a specific assembly mnemonic like `ret` or
@@ -274,7 +278,11 @@ 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
@@ -286,19 +294,27 @@ extern "C" void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef TM,
 
 extern "C" size_t LLVMRustGetTargetFeaturesCount(LLVMTargetMachineRef TM) {
   const TargetMachine *Target = unwrap(TM);
-  const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+#else
+  const MCSubtargetInfo &MCInfo = *Target->getMCSubtargetInfo();
+#endif
   const ArrayRef<SubtargetFeatureKV> FeatTable =
-      MCInfo->getAllProcessorFeatures();
+      MCInfo.getAllProcessorFeatures();
   return FeatTable.size();
 }
 
 extern "C" void LLVMRustGetTargetFeature(LLVMTargetMachineRef TM, size_t Index,
                                          const char **Feature,
                                          const char **Desc) {
   const TargetMachine *Target = unwrap(TM);
-  const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
+#if LLVM_VERSION_GE(23, 0)
+  const MCSubtargetInfo &MCInfo = Target->getMCSubtargetInfo();
+#else
+  const MCSubtargetInfo &MCInfo = *Target->getMCSubtargetInfo();
+#endif
   const ArrayRef<SubtargetFeatureKV> FeatTable =
-      MCInfo->getAllProcessorFeatures();
+      MCInfo.getAllProcessorFeatures();
   const SubtargetFeatureKV Feat = FeatTable[Index];
   *Feature = Feat.Key;
   *Desc = Feat.Desc;