fully exploited the dropped support of LLVM 8

This commit grepped for LLVM_VERSION_GE, LLVM_VERSION_LT, get_major_version and
min-llvm-version and statically evaluated every expression possible
(and sensible) assuming that the LLVM version is >=9 now

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -147,17 +147,9 @@ fn set_probestack(cx: &CodegenCx<'ll, '_>, llfn: &'ll Value) {
 fn translate_obsolete_target_features(feature: &str) -> &str {
     const LLVM9_FEATURE_CHANGES: &[(&str, &str)] =
         &[("+fp-only-sp", "-fp64"), ("-fp-only-sp", "+fp64"), ("+d16", "-d32"), ("-d16", "+d32")];
-    if llvm_util::get_major_version() >= 9 {
-        for &(old, new) in LLVM9_FEATURE_CHANGES {
-            if feature == old {
-                return new;
-            }
-        }
-    } else {
-        for &(old, new) in LLVM9_FEATURE_CHANGES {
-            if feature == new {
-                return old;
-            }
+    for &(old, new) in LLVM9_FEATURE_CHANGES {
+        if feature == old {
+            return new;
         }
     }
     feature

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -377,11 +377,6 @@ fn get_pgo_use_path(config: &ModuleConfig) -> Option<CString> {
 }
 
 pub(crate) fn should_use_new_llvm_pass_manager(config: &ModuleConfig) -> bool {
-    // We only support the new pass manager starting with LLVM 9.
-    if llvm_util::get_major_version() < 9 {
-        return false;
-    }
-
     // The new pass manager is disabled by default.
     config.new_llvm_pass_manager
 }

compiler/rustc_codegen_llvm/src/context.rs

@@ -119,9 +119,6 @@ pub unsafe fn create_module(
     let llmod = llvm::LLVMModuleCreateWithNameInContext(mod_name.as_ptr(), llcx);
 
     let mut target_data_layout = sess.target.data_layout.clone();
-    if llvm_util::get_major_version() < 9 {
-        target_data_layout = strip_function_ptr_alignment(target_data_layout);
-    }
     if llvm_util::get_major_version() < 10
         && (sess.target.arch == "x86" || sess.target.arch == "x86_64")
     {

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -104,7 +104,7 @@ unsafe fn configure_llvm(sess: &Session) {
         }
     }
 
-    if sess.opts.debugging_opts.llvm_time_trace && get_major_version() >= 9 {
+    if sess.opts.debugging_opts.llvm_time_trace {
         // time-trace is not thread safe and running it in parallel will cause seg faults.
         if !sess.opts.debugging_opts.no_parallel_llvm {
             bug!("`-Z llvm-time-trace` requires `-Z no-parallel-llvm")
@@ -122,10 +122,8 @@ unsafe fn configure_llvm(sess: &Session) {
 
 pub fn time_trace_profiler_finish(file_name: &str) {
     unsafe {
-        if get_major_version() >= 9 {
-            let file_name = CString::new(file_name).unwrap();
-            llvm::LLVMTimeTraceProfilerFinish(file_name.as_ptr());
-        }
+        let file_name = CString::new(file_name).unwrap();
+        llvm::LLVMTimeTraceProfilerFinish(file_name.as_ptr());
     }
 }
 

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -16,9 +16,7 @@
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Object/IRObjectFile.h"
 #include "llvm/Passes/PassBuilder.h"
-#if LLVM_VERSION_GE(9, 0)
 #include "llvm/Passes/StandardInstrumentations.h"
-#endif
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
@@ -31,15 +29,11 @@
 #include "llvm-c/Transforms/PassManagerBuilder.h"
 
 #include "llvm/Transforms/Instrumentation.h"
-#if LLVM_VERSION_GE(9, 0)
 #include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
 #include "llvm/Support/TimeProfiler.h"
-#endif
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
 #include "llvm/Transforms/Instrumentation/MemorySanitizer.h"
-#if LLVM_VERSION_GE(9, 0)
 #include "llvm/Transforms/Utils/CanonicalizeAliases.h"
-#endif
 #include "llvm/Transforms/Utils/NameAnonGlobals.h"
 
 using namespace llvm;
@@ -73,20 +67,18 @@ extern "C" void LLVMTimeTraceProfilerInitialize() {
   timeTraceProfilerInitialize(
       /* TimeTraceGranularity */ 0,
       /* ProcName */ "rustc");
-#elif LLVM_VERSION_GE(9, 0)
+#else
   timeTraceProfilerInitialize();
 #endif
 }
 
 extern "C" void LLVMTimeTraceProfilerFinish(const char* FileName) {
-#if LLVM_VERSION_GE(9, 0)
   StringRef FN(FileName);
   std::error_code EC;
   raw_fd_ostream OS(FN, EC, sys::fs::CD_CreateAlways);
 
   timeTraceProfilerWrite(OS);
   timeTraceProfilerCleanup();
-#endif
 }
 
 enum class LLVMRustPassKind {
@@ -127,22 +119,14 @@ extern "C" LLVMPassRef LLVMRustCreateAddressSanitizerFunctionPass(bool Recover)
 extern "C" LLVMPassRef LLVMRustCreateModuleAddressSanitizerPass(bool Recover) {
   const bool CompileKernel = false;
 
-#if LLVM_VERSION_GE(9, 0)
   return wrap(createModuleAddressSanitizerLegacyPassPass(CompileKernel, Recover));
-#else
-  return wrap(createAddressSanitizerModulePass(CompileKernel, Recover));
-#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateMemorySanitizerPass(int TrackOrigins, bool Recover) {
-#if LLVM_VERSION_GE(9, 0)
   const bool CompileKernel = false;
 
   return wrap(createMemorySanitizerLegacyPassPass(
       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
-#else
-  return wrap(createMemorySanitizerLegacyPassPass(TrackOrigins, Recover));
-#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateThreadSanitizerPass() {
@@ -657,8 +641,6 @@ extern "C" typedef void (*LLVMRustSelfProfileBeforePassCallback)(void*, // LlvmS
                                                       const char*);     // IR name
 extern "C" typedef void (*LLVMRustSelfProfileAfterPassCallback)(void*); // LlvmSelfProfiler
 
-#if LLVM_VERSION_GE(9, 0)
-
 std::string LLVMRustwrappedIrGetName(const llvm::Any &WrappedIr) {
   if (any_isa<const Module *>(WrappedIr))
     return any_cast<const Module *>(WrappedIr)->getName().str();
@@ -706,7 +688,6 @@ void LLVMSelfProfileInitializeCallbacks(
         AfterPassCallback(LlvmSelfProfiler);
       });
 }
-#endif
 
 enum class LLVMRustOptStage {
   PreLinkNoLTO,
@@ -739,7 +720,6 @@ LLVMRustOptimizeWithNewPassManager(
     void* LlvmSelfProfiler,
     LLVMRustSelfProfileBeforePassCallback BeforePassCallback,
     LLVMRustSelfProfileAfterPassCallback AfterPassCallback) {
-#if LLVM_VERSION_GE(9, 0)
   Module *TheModule = unwrap(ModuleRef);
   TargetMachine *TM = unwrap(TMRef);
   PassBuilder::OptimizationLevel OptLevel = fromRust(OptLevelRust);
@@ -970,11 +950,6 @@ LLVMRustOptimizeWithNewPassManager(
     UpgradeCallsToIntrinsic(&*I++); // must be post-increment, as we remove
 
   MPM.run(*TheModule, MAM);
-#else
-  // The new pass manager has been available for a long time,
-  // but we don't bother supporting it on old LLVM versions.
-  report_fatal_error("New pass manager only supported since LLVM 9");
-#endif
 }
 
 // Callback to demangle function name
@@ -1325,12 +1300,9 @@ LLVMRustCreateThinLTOData(LLVMRustThinLTOModule *modules,
                               GlobalValue::LinkageTypes NewLinkage) {
     Ret->ResolvedODR[ModuleIdentifier][GUID] = NewLinkage;
   };
-#if LLVM_VERSION_GE(9, 0)
+
   thinLTOResolvePrevailingInIndex(Ret->Index, isPrevailing, recordNewLinkage,
                                   Ret->GUIDPreservedSymbols);
-#else
-  thinLTOResolvePrevailingInIndex(Ret->Index, isPrevailing, recordNewLinkage);
-#endif
 
   // Here we calculate an `ExportedGUIDs` set for use in the `isExported`
   // callback below. This callback below will dictate the linkage for all

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -124,9 +124,7 @@ extern "C" LLVMValueRef LLVMRustGetOrInsertFunction(LLVMModuleRef M,
   return wrap(unwrap(M)
                   ->getOrInsertFunction(StringRef(Name, NameLen),
                                         unwrap<FunctionType>(FunctionTy))
-#if LLVM_VERSION_GE(9, 0)
                   .getCallee()
-#endif
   );
 }
 
@@ -251,11 +249,7 @@ extern "C" void LLVMRustAddDereferenceableOrNullCallSiteAttr(LLVMValueRef Instr,
 extern "C" void LLVMRustAddByValCallSiteAttr(LLVMValueRef Instr, unsigned Index,
                                              LLVMTypeRef Ty) {
   CallBase *Call = unwrap<CallBase>(Instr);
-#if LLVM_VERSION_GE(9, 0)
   Attribute Attr = Attribute::getWithByValType(Call->getContext(), unwrap(Ty));
-#else
-  Attribute Attr = Attribute::get(Call->getContext(), Attribute::ByVal);
-#endif
   Call->addAttribute(Index, Attr);
 }
 
@@ -296,11 +290,7 @@ extern "C" void LLVMRustAddDereferenceableOrNullAttr(LLVMValueRef Fn,
 extern "C" void LLVMRustAddByValAttr(LLVMValueRef Fn, unsigned Index,
                                      LLVMTypeRef Ty) {
   Function *F = unwrap<Function>(Fn);
-#if LLVM_VERSION_GE(9, 0)
   Attribute Attr = Attribute::getWithByValType(F->getContext(), unwrap(Ty));
-#else
-  Attribute Attr = Attribute::get(F->getContext(), Attribute::ByVal);
-#endif
   F->addAttribute(Index, Attr);
 }
 
@@ -616,11 +606,9 @@ static DISubprogram::DISPFlags fromRust(LLVMRustDISPFlags SPFlags) {
   if (isSet(SPFlags & LLVMRustDISPFlags::SPFlagOptimized)) {
     Result |= DISubprogram::DISPFlags::SPFlagOptimized;
   }
-#if LLVM_VERSION_GE(9, 0)
   if (isSet(SPFlags & LLVMRustDISPFlags::SPFlagMainSubprogram)) {
     Result |= DISubprogram::DISPFlags::SPFlagMainSubprogram;
   }
-#endif
 
   return Result;
 }
@@ -744,10 +732,6 @@ extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateFunction(
       DITemplateParameterArray(unwrap<MDTuple>(TParam));
   DISubprogram::DISPFlags llvmSPFlags = fromRust(SPFlags);
   DINode::DIFlags llvmFlags = fromRust(Flags);
-#if LLVM_VERSION_LT(9, 0)
-  if (isSet(SPFlags & LLVMRustDISPFlags::SPFlagMainSubprogram))
-    llvmFlags |= DINode::DIFlags::FlagMainSubprogram;
-#endif
   DISubprogram *Sub = Builder->createFunction(
       unwrapDI<DIScope>(Scope),
       StringRef(Name, NameLen),

src/test/codegen/abi-efiapi.rs

@@ -1,7 +1,6 @@
 // Checks if the correct annotation for the efiapi ABI is passed to llvm.
 
 // revisions:x86_64 i686 aarch64 arm riscv
-// min-llvm-version: 9.0
 // needs-llvm-components: aarch64 arm riscv
 
 //[x86_64] compile-flags: --target x86_64-unknown-uefi

src/test/codegen/force-unwind-tables.rs

@@ -1,4 +1,3 @@
-// min-llvm-version: 8.0
 // compile-flags: -C no-prepopulate-passes -C force-unwind-tables=y
 
 #![crate_type="lib"]

src/test/ui/sanitize/new-llvm-pass-manager-thin-lto.rs

@@ -2,7 +2,6 @@
 // being run when compiling with new LLVM pass manager and ThinLTO.
 // Note: The issue occurred only on non-zero opt-level.
 //
-// min-llvm-version: 9.0
 // needs-sanitizer-support
 // needs-sanitizer-address
 //