rustllvm: Remove conditional code for LLVM < 3.9

We bumped the minimum LLVM to 3.9 in rust-lang#45326.  This just cleans up the
conditional code in the rustllvm C++ wrappers to assume at least 3.9.

src/rustllvm/ArchiveWrapper.cpp

@@ -24,11 +24,7 @@ struct RustArchiveMember {
 
   RustArchiveMember()
       : Filename(nullptr), Name(nullptr),
-#if LLVM_VERSION_GE(3, 8)
         Child(nullptr, nullptr, nullptr)
-#else
-        Child(nullptr, nullptr)
-#endif
   {
   }
   ~RustArchiveMember() {}
@@ -38,13 +34,9 @@ struct RustArchiveIterator {
   bool First;
   Archive::child_iterator Cur;
   Archive::child_iterator End;
-#if LLVM_VERSION_GE(3, 9)
   Error Err;
 
   RustArchiveIterator() : First(true), Err(Error::success()) {}
-#else
-  RustArchiveIterator() : First(true) {}
-#endif
 };
 
 enum class LLVMRustArchiveKind {
@@ -84,19 +76,11 @@ extern "C" LLVMRustArchiveRef LLVMRustOpenArchive(char *Path) {
     return nullptr;
   }
 
-#if LLVM_VERSION_LE(3, 8)
-  ErrorOr<std::unique_ptr<Archive>> ArchiveOr =
-#else
   Expected<std::unique_ptr<Archive>> ArchiveOr =
-#endif
       Archive::create(BufOr.get()->getMemBufferRef());
 
   if (!ArchiveOr) {
-#if LLVM_VERSION_LE(3, 8)
-    LLVMRustSetLastError(ArchiveOr.getError().message().c_str());
-#else
     LLVMRustSetLastError(toString(ArchiveOr.takeError()).c_str());
-#endif
     return nullptr;
   }
 
@@ -114,16 +98,12 @@ extern "C" LLVMRustArchiveIteratorRef
 LLVMRustArchiveIteratorNew(LLVMRustArchiveRef RustArchive) {
   Archive *Archive = RustArchive->getBinary();
   RustArchiveIterator *RAI = new RustArchiveIterator();
-#if LLVM_VERSION_LE(3, 8)
-  RAI->Cur = Archive->child_begin();
-#else
   RAI->Cur = Archive->child_begin(RAI->Err);
   if (RAI->Err) {
     LLVMRustSetLastError(toString(std::move(RAI->Err)).c_str());
     delete RAI;
     return nullptr;
   }
-#endif
   RAI->End = Archive->child_end();
   return RAI;
 }
@@ -141,29 +121,18 @@ LLVMRustArchiveIteratorNext(LLVMRustArchiveIteratorRef RAI) {
   // but instead advance it *before* fetching the child in all later calls.
   if (!RAI->First) {
     ++RAI->Cur;
-#if LLVM_VERSION_GE(3, 9)
     if (RAI->Err) {
       LLVMRustSetLastError(toString(std::move(RAI->Err)).c_str());
       return nullptr;
     }
-#endif
   } else {
     RAI->First = false;
   }
 
   if (RAI->Cur == RAI->End)
     return nullptr;
 
-#if LLVM_VERSION_EQ(3, 8)
-  const ErrorOr<Archive::Child> *Cur = RAI->Cur.operator->();
-  if (!*Cur) {
-    LLVMRustSetLastError(Cur->getError().message().c_str());
-    return nullptr;
-  }
-  const Archive::Child &Child = Cur->get();
-#else
   const Archive::Child &Child = *RAI->Cur.operator->();
-#endif
   Archive::Child *Ret = new Archive::Child(Child);
 
   return Ret;
@@ -239,18 +208,13 @@ LLVMRustWriteArchive(char *Dst, size_t NumMembers,
                      const LLVMRustArchiveMemberRef *NewMembers,
                      bool WriteSymbtab, LLVMRustArchiveKind RustKind) {
 
-#if LLVM_VERSION_LE(3, 8)
-  std::vector<NewArchiveIterator> Members;
-#else
   std::vector<NewArchiveMember> Members;
-#endif
   auto Kind = fromRust(RustKind);
 
   for (size_t I = 0; I < NumMembers; I++) {
     auto Member = NewMembers[I];
     assert(Member->Name);
     if (Member->Filename) {
-#if LLVM_VERSION_GE(3, 9)
       Expected<NewArchiveMember> MOrErr =
           NewArchiveMember::getFile(Member->Filename, true);
       if (!MOrErr) {
@@ -261,30 +225,17 @@ LLVMRustWriteArchive(char *Dst, size_t NumMembers,
       MOrErr->MemberName = sys::path::filename(MOrErr->MemberName);
 #endif
       Members.push_back(std::move(*MOrErr));
-#elif LLVM_VERSION_EQ(3, 8)
-      Members.push_back(NewArchiveIterator(Member->Filename));
-#else
-      Members.push_back(NewArchiveIterator(Member->Filename, Member->Name));
-#endif
     } else {
-#if LLVM_VERSION_LE(3, 8)
-      Members.push_back(NewArchiveIterator(Member->Child, Member->Name));
-#else
       Expected<NewArchiveMember> MOrErr =
           NewArchiveMember::getOldMember(Member->Child, true);
       if (!MOrErr) {
         LLVMRustSetLastError(toString(MOrErr.takeError()).c_str());
         return LLVMRustResult::Failure;
       }
       Members.push_back(std::move(*MOrErr));
-#endif
     }
   }
-#if LLVM_VERSION_GE(3, 8)
   auto Pair = writeArchive(Dst, Members, WriteSymbtab, Kind, true, false);
-#else
-  auto Pair = writeArchive(Dst, Members, WriteSymbtab, Kind, true);
-#endif
   if (!Pair.second)
     return LLVMRustResult::Success;
   LLVMRustSetLastError(Pair.second.message().c_str());

src/rustllvm/PassWrapper.cpp

@@ -58,9 +58,6 @@ extern "C" void LLVMInitializePasses() {
   initializeVectorization(Registry);
   initializeIPO(Registry);
   initializeAnalysis(Registry);
-#if LLVM_VERSION_EQ(3, 7)
-  initializeIPA(Registry);
-#endif
   initializeTransformUtils(Registry);
   initializeInstCombine(Registry);
   initializeInstrumentation(Registry);
@@ -272,18 +269,10 @@ enum class LLVMRustRelocMode {
   ROPIRWPI,
 };
 
-#if LLVM_VERSION_LE(3, 8)
-static Reloc::Model fromRust(LLVMRustRelocMode RustReloc) {
-#else
 static Optional<Reloc::Model> fromRust(LLVMRustRelocMode RustReloc) {
-#endif
   switch (RustReloc) {
   case LLVMRustRelocMode::Default:
-#if LLVM_VERSION_LE(3, 8)
-    return Reloc::Default;
-#else
     return None;
-#endif
   case LLVMRustRelocMode::Static:
     return Reloc::Static;
   case LLVMRustRelocMode::PIC:
@@ -389,9 +378,6 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
   }
 
   TargetOptions Options;
-#if LLVM_VERSION_LE(3, 8)
-  Options.PositionIndependentExecutable = PositionIndependentExecutable;
-#endif
 
   Options.FloatABIType = FloatABI::Default;
   if (UseSoftFloat) {
@@ -719,10 +705,6 @@ extern "C" void LLVMRustRunRestrictionPass(LLVMModuleRef M, char **Symbols,
                                            size_t Len) {
   llvm::legacy::PassManager passes;
 
-#if LLVM_VERSION_LE(3, 8)
-  ArrayRef<const char *> Ref(Symbols, Len);
-  passes.add(llvm::createInternalizePass(Ref));
-#else
   auto PreserveFunctions = [=](const GlobalValue &GV) {
     for (size_t I = 0; I < Len; I++) {
       if (GV.getName() == Symbols[I]) {
@@ -733,7 +715,6 @@ extern "C" void LLVMRustRunRestrictionPass(LLVMModuleRef M, char **Symbols,
   };
 
   passes.add(llvm::createInternalizePass(PreserveFunctions));
-#endif
 
   passes.run(*unwrap(M));
 }
@@ -769,9 +750,7 @@ extern "C" LLVMTargetDataRef LLVMRustGetModuleDataLayout(LLVMModuleRef M) {
 }
 
 extern "C" void LLVMRustSetModulePIELevel(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(3, 9)
   unwrap(M)->setPIELevel(PIELevel::Level::Large);
-#endif
 }
 
 extern "C" bool