Update the minimum external LLVM to 18

compiler/rustc_llvm/llvm-wrapper/ArchiveWrapper.cpp

@@ -196,14 +196,10 @@ extern "C" LLVMRustResult LLVMRustWriteArchive(
     }
   }
 
-#if LLVM_VERSION_LT(18, 0)
-  auto Result = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
-#else
   auto SymtabMode = WriteSymbtab ? SymtabWritingMode::NormalSymtab
                                  : SymtabWritingMode::NoSymtab;
   auto Result =
       writeArchive(Dst, Members, SymtabMode, Kind, true, false, nullptr, isEC);
-#endif
   if (!Result)
     return LLVMRustResult::Success;
   LLVMRustSetLastError(toString(std::move(Result)).c_str());

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -58,17 +58,10 @@ fromRust(LLVMRustCounterMappingRegionKind Kind) {
     return coverage::CounterMappingRegion::GapRegion;
   case LLVMRustCounterMappingRegionKind::BranchRegion:
     return coverage::CounterMappingRegion::BranchRegion;
-#if LLVM_VERSION_GE(18, 0)
   case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
     return coverage::CounterMappingRegion::MCDCDecisionRegion;
   case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
     return coverage::CounterMappingRegion::MCDCBranchRegion;
-#else
-  case LLVMRustCounterMappingRegionKind::MCDCDecisionRegion:
-    break;
-  case LLVMRustCounterMappingRegionKind::MCDCBranchRegion:
-    break;
-#endif
   }
   report_fatal_error("Bad LLVMRustCounterMappingRegionKind!");
 }
@@ -100,7 +93,7 @@ struct LLVMRustMCDCParameters {
 // https://github.com/rust-lang/llvm-project/blob/66a2881a/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L253-L263
 // and representations in 19
 // https://github.com/llvm/llvm-project/blob/843cc474faefad1d639f4c44c1cf3ad7dbda76c8/llvm/include/llvm/ProfileData/Coverage/MCDCTypes.h
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
 static coverage::CounterMappingRegion::MCDCParameters
 fromRust(LLVMRustMCDCParameters Params) {
   auto parameter = coverage::CounterMappingRegion::MCDCParameters{};
@@ -126,7 +119,7 @@ fromRust(LLVMRustMCDCParameters Params) {
   }
   report_fatal_error("Bad LLVMRustMCDCParametersTag!");
 }
-#elif LLVM_VERSION_GE(19, 0)
+#else
 static coverage::mcdc::Parameters fromRust(LLVMRustMCDCParameters Params) {
   switch (Params.Tag) {
   case LLVMRustMCDCParametersTag::None:
@@ -221,7 +214,7 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
            RustMappingRegions, NumMappingRegions)) {
     MappingRegions.emplace_back(
         fromRust(Region.Count), fromRust(Region.FalseCount),
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
         // LLVM 19 may move this argument to last.
         fromRust(Region.MCDCParameters),
 #endif

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -26,21 +26,19 @@
 #include "llvm/Passes/StandardInstrumentations.h"
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/TargetParser/Host.h"
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/FunctionImport.h"
 #include "llvm/Transforms/IPO/Internalize.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"
 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
-#include "llvm/Transforms/Utils/AddDiscriminators.h"
-#include "llvm/Transforms/Utils/FunctionImportUtils.h"
-#if LLVM_VERSION_GE(18, 0)
-#include "llvm/TargetParser/Host.h"
-#endif
-#include "llvm/Support/TimeProfiler.h"
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
 #include "llvm/Transforms/Instrumentation/DataFlowSanitizer.h"
+#include "llvm/Transforms/Utils/AddDiscriminators.h"
+#include "llvm/Transforms/Utils/FunctionImportUtils.h"
 #if LLVM_VERSION_GE(19, 0)
 #include "llvm/Support/PGOOptions.h"
 #endif
@@ -240,11 +238,7 @@ enum class LLVMRustCodeGenOptLevel {
   Aggressive,
 };
 
-#if LLVM_VERSION_GE(18, 0)
 using CodeGenOptLevelEnum = llvm::CodeGenOptLevel;
-#else
-using CodeGenOptLevelEnum = llvm::CodeGenOpt::Level;
-#endif
 
 static CodeGenOptLevelEnum fromRust(LLVMRustCodeGenOptLevel Level) {
   switch (Level) {
@@ -370,21 +364,16 @@ extern "C" void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef TM,
 }
 
 extern "C" size_t LLVMRustGetTargetFeaturesCount(LLVMTargetMachineRef TM) {
-#if LLVM_VERSION_GE(18, 0)
   const TargetMachine *Target = unwrap(TM);
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
       MCInfo->getAllProcessorFeatures();
   return FeatTable.size();
-#else
-  return 0;
-#endif
 }
 
 extern "C" void LLVMRustGetTargetFeature(LLVMTargetMachineRef TM, size_t Index,
                                          const char **Feature,
                                          const char **Desc) {
-#if LLVM_VERSION_GE(18, 0)
   const TargetMachine *Target = unwrap(TM);
   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
   const ArrayRef<SubtargetFeatureKV> FeatTable =
@@ -392,7 +381,6 @@ extern "C" void LLVMRustGetTargetFeature(LLVMTargetMachineRef TM, size_t Index,
   const SubtargetFeatureKV Feat = FeatTable[Index];
   *Feature = Feat.Key;
   *Desc = Feat.Desc;
-#endif
 }
 
 extern "C" const char *LLVMRustGetHostCPUName(size_t *len) {
@@ -569,17 +557,9 @@ enum class LLVMRustFileType {
 static CodeGenFileType fromRust(LLVMRustFileType Type) {
   switch (Type) {
   case LLVMRustFileType::AssemblyFile:
-#if LLVM_VERSION_GE(18, 0)
     return CodeGenFileType::AssemblyFile;
-#else
-    return CGFT_AssemblyFile;
-#endif
   case LLVMRustFileType::ObjectFile:
-#if LLVM_VERSION_GE(18, 0)
     return CodeGenFileType::ObjectFile;
-#else
-    return CGFT_ObjectFile;
-#endif
   default:
     report_fatal_error("Bad FileType.");
   }
@@ -865,11 +845,7 @@ extern "C" LLVMRustResult LLVMRustOptimize(
           // cargo run tests in multhreading mode by default
           // so use atomics for coverage counters
           Options.Atomic = true;
-#if LLVM_VERSION_GE(18, 0)
           MPM.addPass(InstrProfilingLoweringPass(Options, false));
-#else
-          MPM.addPass(InstrProfiling(Options, false));
-#endif
         });
   }
 
@@ -1210,7 +1186,6 @@ 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
@@ -1218,11 +1193,6 @@ struct LLVMRustThinLTOData {
 #endif
   DenseMap<StringRef, FunctionImporter::ExportSetTy> ExportLists;
   DenseMap<StringRef, GVSummaryMapTy> ModuleToDefinedGVSummaries;
-#else
-  StringMap<FunctionImporter::ImportMapTy> ImportLists;
-  StringMap<FunctionImporter::ExportSetTy> ExportLists;
-  StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries;
-#endif
   StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
 
   LLVMRustThinLTOData() : Index(/* HaveGVs = */ false) {}
@@ -1274,11 +1244,7 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules, int num_modules,
 
     Ret->ModuleMap[module->identifier] = mem_buffer;
 
-#if LLVM_VERSION_GE(18, 0)
     if (Error Err = readModuleSummaryIndex(mem_buffer, Ret->Index)) {
-#else
-    if (Error Err = readModuleSummaryIndex(mem_buffer, Ret->Index, i)) {
-#endif
       LLVMRustSetLastError(toString(std::move(Err)).c_str());
       return nullptr;
     }

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -310,16 +310,10 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) {
     return Attribute::SafeStack;
   case FnRetThunkExtern:
     return Attribute::FnRetThunkExtern;
-#if LLVM_VERSION_GE(18, 0)
   case Writable:
     return Attribute::Writable;
   case DeadOnUnwind:
     return Attribute::DeadOnUnwind;
-#else
-  case Writable:
-  case DeadOnUnwind:
-    report_fatal_error("Not supported on this LLVM version");
-#endif
   }
   report_fatal_error("bad AttributeKind");
 }
@@ -1061,11 +1055,7 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateStaticMemberType(
   return wrap(Builder->createStaticMemberType(
       unwrapDI<DIDescriptor>(Scope), StringRef(Name, NameLen),
       unwrapDI<DIFile>(File), LineNo, unwrapDI<DIType>(Ty), fromRust(Flags),
-      unwrap<llvm::ConstantInt>(val),
-#if LLVM_VERSION_GE(18, 0)
-      llvm::dwarf::DW_TAG_member,
-#endif
-      AlignInBits));
+      unwrap<llvm::ConstantInt>(val), llvm::dwarf::DW_TAG_member, AlignInBits));
 }
 
 extern "C" LLVMMetadataRef
@@ -1182,10 +1172,7 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateEnumerationType(
       unwrapDI<DIDescriptor>(Scope), StringRef(Name, NameLen),
       unwrapDI<DIFile>(File), LineNumber, SizeInBits, AlignInBits,
       DINodeArray(unwrapDI<MDTuple>(Elements)), unwrapDI<DIType>(ClassTy),
-#if LLVM_VERSION_GE(18, 0)
-      /* RunTimeLang */ 0,
-#endif
-      "", IsScoped));
+      /* RunTimeLang */ 0, "", IsScoped));
 }
 
 extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateUnionType(
@@ -1552,27 +1539,19 @@ LLVMRustGetInstrProfIncrementIntrinsic(LLVMModuleRef M) {
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCParametersIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_parameters));
-#else
-  report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
-#endif
 }
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_tvbitmap_update));
-#else
-  report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
-#endif
 }
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
+#if LLVM_VERSION_LT(19, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_condbitmap_update));
 #else

compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp

@@ -150,11 +150,9 @@ extern "C" bool LLVMRustIsECObject(char *BufPtr, size_t BufLen) {
     return cast<llvm::object::COFFObjectFile>(&*Obj)->getMachine() !=
            COFF::IMAGE_FILE_MACHINE_ARM64;
 
-#if LLVM_VERSION_GE(18, 0)
   if (Obj->isCOFFImportFile())
     return cast<llvm::object::COFFImportFile>(&*Obj)->getMachine() !=
            COFF::IMAGE_FILE_MACHINE_ARM64;
-#endif
 
   if (Obj->isIR()) {
     Expected<std::string> TripleStr =