ldc-developers · kinke · Oct 15, 2021 · Oct 16, 2021 · Oct 16, 2021 · Oct 16, 2021
diff --git a/.azure-pipelines/1-posix-setup.yml b/.azure-pipelines/1-posix-setup.yml
@@ -63,6 +63,10 @@ steps:
     fi
     mkdir llvm
     tar -xf llvm.tar.xz --strip 1 -C llvm
+    # Non-Mac: make lld the default linker
+    if [ "$CI_OS" != "osx" ]; then
+      sudo ln -sf "$PWD/llvm/bin/ld.lld" /usr/bin/ld
+    fi
     # Set PARALLEL_JOBS env variable and persist it for future steps
     if [ "$CI_OS" = "osx" ]; then
       PARALLEL_JOBS=$(sysctl -n hw.logicalcpu)

diff --git a/.azure-pipelines/4a-mac_x64.yml b/.azure-pipelines/4a-mac_x64.yml
@@ -38,9 +38,9 @@ steps:
       CMAKE_OSX_DEPLOYMENT_TARGET=$IOS_DEPLOYMENT_TARGET \
       BUILD_LTO_LIBS=ON
     mkdir installed/lib-{arm64,ios-arm64,ios-x86_64}
-    cp -a build-libs-arm64/lib/*.{a,dylib} installed/lib-arm64
-    cp -a build-libs-ios-arm64/lib/*.{a,dylib} installed/lib-ios-arm64
-    cp -a build-libs-ios-x86_64/lib/*.{a,dylib} installed/lib-ios-x86_64
+    cp -a build-libs-arm64/lib/*.{a,dylib,o} installed/lib-arm64
+    cp -a build-libs-ios-arm64/lib/*.{a,dylib,o} installed/lib-ios-arm64
+    cp -a build-libs-ios-x86_64/lib/*.{a,dylib,o} installed/lib-ios-x86_64
     sections="
     \"arm64-apple-macos\":
     {

diff --git a/.github/workflows/supported_llvm_versions.yml b/.github/workflows/supported_llvm_versions.yml
@@ -16,22 +16,22 @@ jobs:
             os: ubuntu-18.04
             host_dc: ldc-beta
             llvm_version: "11.1.0"
-            cmake_opts: "-DRT_SUPPORT_SANITIZERS=ON"
+            cmake_opts: "-DBUILD_SHARED_LIBS=ON -DRT_SUPPORT_SANITIZERS=ON"
           - job_name: Ubuntu 18.04, LLVM 9, latest LDC beta
             os: ubuntu-18.04
             host_dc: ldc-beta
             llvm_version: "9.0.1"
-            cmake_opts: "-DBUILD_SHARED_LIBS=ON -DRT_SUPPORT_SANITIZERS=ON"
+            cmake_opts: "-DBUILD_SHARED_LIBS=OFF -DRT_SUPPORT_SANITIZERS=ON"
           - job_name: Ubuntu 18.04, LLVM 8, latest LDC beta
             os: ubuntu-18.04
             host_dc: ldc-beta
             llvm_version: "8.0.0"
-            cmake_opts: "-DBUILD_SHARED_LIBS=OFF"
+            cmake_opts: "-DLIB_SUFFIX=64"
           - job_name: Ubuntu 18.04, LLVM 6, latest DMD beta
             os: ubuntu-18.04
             host_dc: dmd-beta
             llvm_version: "6.0.1"
-            cmake_opts: "-DLIB_SUFFIX=64 -DLDC_LINK_MANUALLY=ON"
+            cmake_opts: "-DLDC_LINK_MANUALLY=ON"
           - job_name: Latest macOS, LLVM 10, latest DMD beta
             os: macos-latest
             host_dc: dmd-beta

diff --git a/.travis.yml b/.travis.yml
@@ -134,9 +134,9 @@ script:
   - installed/bin/ldc2 hello.d -of=hello -link-defaultlib-shared
   - ./hello
   # Run hello-world integration test with LTO
-  - installed/bin/ldc2 hello.d -of=hello_thin -flto=thin -defaultlib=phobos2-ldc-lto,druntime-ldc-lto
+  - installed/bin/ldc2 hello.d -of=hello_thin -linker=gold -flto=thin -defaultlib=phobos2-ldc-lto,druntime-ldc-lto
   - ./hello_thin
-  - installed/bin/ldc2 hello.d -of=hello_full -flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto
+  - installed/bin/ldc2 hello.d -of=hello_full -linker=gold -flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto
   - ./hello_full
   # Run dynamic-compile integration test
   # FIXME: disabled since LLVM 12, needs https://github.com/ldc-developers/ldc/pull/3184

diff --git a/azure-pipelines.yml b/azure-pipelines.yml
@@ -63,14 +63,15 @@ jobs:
   variables:
     CI_OS: linux
     ARCH: x86_64
-    # To improve portability of the generated binaries, link the C++ standard library statically.
     BOOTSTRAP_CMAKE_FLAGS: -DBUILD_LTO_LIBS=ON
+    # To improve portability of the generated binaries, link the C++ standard library statically.
+    # FIXME: need to use ld.gold for LTOing LDC itself for now, fixed in frontend v2.099
     EXTRA_CMAKE_FLAGS: >
       -DMULTILIB=ON
       -DBUILD_LTO_LIBS=ON
       -DCMAKE_EXE_LINKER_FLAGS=-static-libstdc++
       -DJITRT_EXTRA_LDFLAGS=-static-libstdc++
-      -DD_COMPILER_FLAGS="-O -flto=full -defaultlib=phobos2-ldc-lto,druntime-ldc-lto"
+      -DD_COMPILER_FLAGS="-O -flto=full -linker=gold -defaultlib=phobos2-ldc-lto,druntime-ldc-lto"
       -DEXTRA_CXXFLAGS=-flto=full
   steps:
     - template: .azure-pipelines/1-posix-setup.yml

diff --git a/driver/linker-gcc.cpp b/driver/linker-gcc.cpp
@@ -489,6 +489,14 @@ void ArgsBuilder::build(llvm::StringRef outputPath,
     args.push_back(objfile);
   }
 
+  // add precompiled rt.dso object file (in lib directory) when linking
+  // against shared druntime
+  const auto &libDirs = ConfigFile::instance.libDirs();
+  if (!defaultLibNames.empty() && linkAgainstSharedDefaultLibs() &&
+      !libDirs.empty()) {
+    args.push_back((llvm::Twine(libDirs[0]) + "/ldc_rt.dso.o").str());
+  }
+
   // Link with profile-rt library when generating an instrumented binary.
   if (opts::isInstrumentingForPGO()) {
     addProfileRuntimeLinkFlags(*global.params.targetTriple);
@@ -533,7 +541,7 @@ void ArgsBuilder::build(llvm::StringRef outputPath,
   addUserSwitches();
 
   // lib dirs
-  for (const char *dir_c : ConfigFile::instance.libDirs()) {
+  for (const char *dir_c : libDirs) {
     const llvm::StringRef dir(dir_c);
     if (!dir.empty())
       args.push_back(("-L" + dir).str());
@@ -587,22 +595,12 @@ void ArgsBuilder::build(llvm::StringRef outputPath,
 void ArgsBuilder::addLinker() {
   llvm::StringRef linker = opts::linker;
 
-  // We have a default linker preference for Linux targets. It can be disabled
-  // via `-linker=` (explicitly empty).
-  if (global.params.targetTriple->isOSLinux() &&
+  // Default to ld.bfd for Android (placing .tdata and .tbss sections adjacent
+  // to each other as required by druntime's rt.sections_android, contrary to
+  // gold and lld as of Android NDK r21d).
+  if (global.params.targetTriple->getEnvironment() == llvm::Triple::Android &&
       opts::linker.getNumOccurrences() == 0) {
-    // Default to ld.bfd for Android (placing .tdata and .tbss sections adjacent
-    // to each other as required by druntime's rt.sections_android, contrary to
-    // gold and lld as of Android NDK r21d).
-    if (global.params.targetTriple->getEnvironment() == llvm::Triple::Android) {
-      linker = "bfd";
-    }
-    // Otherwise default to ld.gold for Linux due to ld.bfd issues with ThinLTO
-    // (see #2278) and older bfd versions stripping llvm.used symbols (e.g.,
-    // ModuleInfo refs) with --gc-sections (see #2870).
-    else {
-      linker = "gold";
-    }
+    linker = "bfd";
   }
 
   if (!linker.empty())

diff --git a/driver/linker-msvc.cpp b/driver/linker-msvc.cpp
@@ -148,10 +148,12 @@ int linkObjToBinaryMSVC(llvm::StringRef outputPath,
     args.push_back(objfile);
   }
 
-  // add precompiled rt.dso_windows object file (in lib directory) when linking
+  // add precompiled rt.dso object file (in lib directory) when linking
   // against shared druntime
-  if (!defaultLibNames.empty() && linkAgainstSharedDefaultLibs()) {
-    args.push_back("dso_windows.obj");
+  const auto &libDirs = ConfigFile::instance.libDirs();
+  if (!defaultLibNames.empty() && linkAgainstSharedDefaultLibs() &&
+      !libDirs.empty()) {
+    args.push_back((llvm::Twine(libDirs[0]) + "/ldc_rt.dso.obj").str());
   }
 
   // .res/.def files
@@ -197,16 +199,14 @@ int linkObjToBinaryMSVC(llvm::StringRef outputPath,
   }
 
   // lib dirs
-  const auto &libDirs = ConfigFile::instance.libDirs();
   for (const char *dir_c : libDirs) {
     const llvm::StringRef dir(dir_c);
     if (!dir.empty())
       args.push_back(("/LIBPATH:" + dir).str());
   }
 
   if (useInternalToolchain && !libDirs.empty()) {
-    args.push_back(
-        (llvm::Twine("/LIBPATH:") + *libDirs.begin() + "/mingw").str());
+    args.push_back((llvm::Twine("/LIBPATH:") + libDirs[0] + "/mingw").str());
   }
 
   // default libs

diff --git a/gen/modules.cpp b/gen/modules.cpp
@@ -83,73 +83,31 @@ void Module::checkAndAddOutputFile(const FileName &file) {
 }
 
 namespace {
-/// Ways the druntime module registry system can be implemented.
+/// Ways the druntime ModuleInfo registry system can be implemented.
 enum class RegistryStyle {
-  /// Modules are inserted into a linked list starting at the _Dmodule_ref
-  /// global.
+  /// ModuleInfo refs are inserted into a linked list starting at the
+  /// _Dmodule_ref global.
   legacyLinkedList,
 
-  /// Module references are emitted into the .minfo/__minfo section.
-  sectionSimple,
-
-  /// Module references are emitted into the __minfo section. Global
-  /// constructors/destructors make sure _d_dso_registry is invoked once per ELF
-  /// object.
-  sectionELF,
-
-  /// Module references are emitted into the .minfo section. Global
-  /// constructors/destructors make sure _d_dso_registry is invoked once per
-  /// shared object. A "TLS anchor" function to identify the TLS range
-  /// corresponding to this image is also passed to druntime.
-  sectionDarwin
+  /// Pointers to defined ModuleInfos are emitted into the special .minfo /
+  /// __minfo section. A linked binary then contains pointers to all ModuleInfos
+  /// of linked object files in that section.
+  section,
 };
 
-/// Returns the module registry style to use for the current target triple.
+/// Returns the ModuleInfo registry style to use for the current target triple.
 RegistryStyle getModuleRegistryStyle() {
   const auto &t = *global.params.targetTriple;
-
   if (t.isOSWindows() || t.getEnvironment() == llvm::Triple::Android ||
-      t.isOSBinFormatWasm()) {
-    return RegistryStyle::sectionSimple;
-  }
-
-  if (t.isOSDarwin()) {
-    return RegistryStyle::sectionDarwin;
-  }
-
-  if (t.isOSLinux() || t.isOSFreeBSD() || t.isOSNetBSD() || t.isOSOpenBSD() ||
+      t.isOSBinFormatWasm() || t.isOSDarwin() || t.isOSLinux() ||
+      t.isOSFreeBSD() || t.isOSNetBSD() || t.isOSOpenBSD() ||
       t.isOSDragonFly()) {
-    return RegistryStyle::sectionELF;
+    return RegistryStyle::section;
   }
 
   return RegistryStyle::legacyLinkedList;
 }
 
-LLGlobalVariable *declareDSOGlobal(llvm::StringRef mangledName, LLType *type,
-                                   bool isThreadLocal = false) {
-  auto global = declareGlobal(Loc(), gIR->module, type, mangledName, false,
-                              isThreadLocal, false);
-  global->setVisibility(LLGlobalValue::HiddenVisibility);
-  return global;
-}
-
-LLGlobalVariable *defineDSOGlobal(llvm::StringRef mangledName, LLConstant *init,
-                                  bool isThreadLocal = false) {
-  auto global =
-      defineGlobal(Loc(), gIR->module, mangledName, init,
-                   LLGlobalValue::LinkOnceODRLinkage, false, isThreadLocal);
-  global->setVisibility(LLGlobalValue::HiddenVisibility);
-  return global;
-}
-
-LLFunction *createDSOFunction(llvm::StringRef mangledName,
-                              LLFunctionType *type) {
-  auto fn = LLFunction::Create(type, LLGlobalValue::LinkOnceODRLinkage,
-                               mangledName, &gIR->module);
-  fn->setVisibility(LLGlobalValue::HiddenVisibility);
-  return fn;
-}
-
 /// Build ModuleReference and register function, to register the module info in
 /// the global linked list.
 ///
@@ -222,160 +180,26 @@ LLFunction *build_module_reference_and_ctor(const char *moduleMangle,
   return ctor;
 }
 
-/// Builds a void*() function with hidden visibility that returns the address of
-/// a dummy TLS global (also with hidden visibility).
-///
-/// The global is non-zero-initialised and aligned to 16 bytes.
-llvm::Function *buildGetTLSAnchor() {
-  // Create a dummmy TLS global private to this module.
-  const auto one = llvm::ConstantInt::get(LLType::getInt8Ty(gIR->context()), 1);
-  const auto anchor =
-      defineDSOGlobal("ldc.tls_anchor", one, /*isThreadLocal=*/true);
-  anchor->setAlignment(LLMaybeAlign(16));
-
-  const auto getAnchor = createDSOFunction(
-      "ldc.get_tls_anchor", LLFunctionType::get(getVoidPtrType(), false));
-
-  IRBuilder<> builder(llvm::BasicBlock::Create(gIR->context(), "", getAnchor));
-  builder.CreateRet(anchor);
-
-  return getAnchor;
-}
-
-/// Builds the ldc.register_dso function, which is called by the global
-/// {c, d}tors to invoke _d_dso_registry.
-///
-/// Pseudocode:
-/// void ldc.register_dso() {
-///   auto record = {1, dsoSlot, minfoBeg, minfoEnd[, getTlsAnchor]};
-///   _d_dso_registry(cast(CompilerDSOData*)&record);
-/// }
-///
-/// On Darwin platforms, the record contains an extra pointer to a function
-/// which returns the address of a TLS global.
-llvm::Function *buildRegisterDSO(RegistryStyle style, llvm::Value *dsoSlot,
-                                 llvm::Value *minfoBeg, llvm::Value *minfoEnd) {
-  const auto fn = createDSOFunction(
-      "ldc.register_dso",
-      LLFunctionType::get(LLType::getVoidTy(gIR->context()), false));
-
-  const auto dsoRegistry =
-      getRuntimeFunction(Loc(), gIR->module, "_d_dso_registry");
-  const auto recordPtrTy = dsoRegistry->getFunctionType()->getContainedType(1);
-
-  llvm::Function *getTlsAnchorPtr = nullptr;
-  if (style == RegistryStyle::sectionDarwin) {
-    getTlsAnchorPtr = buildGetTLSAnchor();
-  }
-
-  {
-    const auto bb = llvm::BasicBlock::Create(gIR->context(), "", fn);
-    IRBuilder<> b(bb);
-
-    llvm::Constant *version = DtoConstSize_t(1);
-    llvm::SmallVector<llvm::Type *, 6> memberTypes;
-    memberTypes.push_back(version->getType());
-    memberTypes.push_back(dsoSlot->getType());
-    memberTypes.push_back(minfoBeg->getType());
-    memberTypes.push_back(minfoEnd->getType());
-    if (style == RegistryStyle::sectionDarwin) {
-      memberTypes.push_back(getTlsAnchorPtr->getType());
-    }
-    llvm::StructType *stype =
-        llvm::StructType::get(gIR->context(), memberTypes, false);
-    llvm::Value *record = b.CreateAlloca(stype);
-
-    unsigned i = 0;
-    b.CreateStore(version, b.CreateStructGEP(stype, record, i++));
-    b.CreateStore(dsoSlot, b.CreateStructGEP(stype, record, i++));
-    b.CreateStore(minfoBeg, b.CreateStructGEP(stype, record, i++));
-    b.CreateStore(minfoEnd, b.CreateStructGEP(stype, record, i++));
-    if (style == RegistryStyle::sectionDarwin) {
-      b.CreateStore(getTlsAnchorPtr, b.CreateStructGEP(stype, record, i++));
-    }
-
-    b.CreateCall(dsoRegistry, b.CreateBitCast(record, recordPtrTy));
-    b.CreateRetVoid();
-  }
-
-  return fn;
-}
-
-void emitModuleRefToSection(RegistryStyle style, std::string moduleMangle,
+// Emits a pointer to the specified ModuleInfo into the special
+// .minfo (COFF & MachO) / __minfo section.
+void emitModuleRefToSection(std::string moduleMangle,
                             llvm::Constant *thisModuleInfo) {
-  assert(style == RegistryStyle::sectionSimple ||
-         style == RegistryStyle::sectionELF ||
-         style == RegistryStyle::sectionDarwin);
-  // Only for the first D module to be emitted into this llvm::Module we need to
-  // create the global ctors/dtors. The magic linker symbols used to get the
-  // start and end of the .minfo section also only need to be emitted for the
-  // first D module.
-  // For all subsequent ones, we just need to emit an additional reference into
-  // the .minfo section.
-  const bool isFirst = !gIR->module.getGlobalVariable("ldc.dso_slot");
-
   const auto moduleInfoPtrTy = DtoPtrToType(getModuleInfoType());
-  const auto moduleInfoRefsSectionName =
-      global.params.targetTriple->isWindowsMSVCEnvironment()
+
+  const auto &triple = *global.params.targetTriple;
+  const auto sectionName =
+      triple.isOSBinFormatCOFF()
           ? ".minfo"
-          : style == RegistryStyle::sectionDarwin ? "__DATA,.minfo" : "__minfo";
+          : triple.isOSBinFormatMachO() ? "__DATA,.minfo" : "__minfo";
 
   const auto thismrefIRMangle =
       getIRMangledModuleRefSymbolName(moduleMangle.c_str());
-  auto thismref = defineDSOGlobal(thismrefIRMangle,
-                                  DtoBitCast(thisModuleInfo, moduleInfoPtrTy));
-  thismref->setSection(moduleInfoRefsSectionName);
+  auto thismref = defineGlobal(Loc(), gIR->module, thismrefIRMangle,
+                               DtoBitCast(thisModuleInfo, moduleInfoPtrTy),
+                               LLGlobalValue::LinkOnceODRLinkage, false, false);
+  thismref->setVisibility(LLGlobalValue::HiddenVisibility);
+  thismref->setSection(sectionName);
   gIR->usedArray.push_back(thismref);
-
-  if (!isFirst || style == RegistryStyle::sectionSimple) {
-    // Nothing left to do.
-    return;
-  }
-
-  // Use magic linker symbol names to obtain the begin and end of the .minfo
-  // section.
-  const auto magicBeginSymbolName = (style == RegistryStyle::sectionDarwin)
-                                        ? "\1section$start$__DATA$.minfo"
-                                        : "__start___minfo";
-  const auto magicEndSymbolName = (style == RegistryStyle::sectionDarwin)
-                                      ? "\1section$end$__DATA$.minfo"
-                                      : "__stop___minfo";
-  auto minfoBeg = declareDSOGlobal(magicBeginSymbolName, moduleInfoPtrTy);
-  auto minfoEnd = declareDSOGlobal(magicEndSymbolName, moduleInfoPtrTy);
-
-  // We want to have one global constructor and destructor per object (i.e.
-  // executable/shared library) that calls _d_dso_registry with the respective
-  // DSO record.
-  // To enable safe direct linking of D objects (e.g., "g++ dcode.o cppcode.o"),
-  // we emit a pair of global {c,d}tors into each object file, both pointing to
-  // a common ldc.register_dso() function.
-  // These per-object-file pairs will be folded to a single one when linking the
-  // DSO, together with the ldc.dso_slot globals and associated
-  // ldc.register_dso() functions.
-
-  // This is the DSO slot for use by the druntime implementation.
-  const auto dsoSlot =
-      defineDSOGlobal("ldc.dso_slot", getNullPtr(getVoidPtrType()));
-
-  const auto registerDSO = buildRegisterDSO(style, dsoSlot, minfoBeg, minfoEnd);
-
-  // We need to discard the {c,d}tor refs if this IR module's ldc.register_dso()
-  // function is discarded to prevent duplicate refs.
-  // Unfortunately, this doesn't work for macOS (v10.12, Xcode v9.2, LLVM
-  // v7.0.0).
-  if (style == RegistryStyle::sectionELF) {
-    llvm::appendToGlobalCtors(gIR->module, registerDSO, 65535, registerDSO);
-    llvm::appendToGlobalDtors(gIR->module, registerDSO, 65535, registerDSO);
-    return;
-  }
-
-  // macOS: emit the {c,d}tor refs manually
-  const auto dsoCtor = defineDSOGlobal("ldc.dso_ctor", registerDSO);
-  const auto dsoDtor = defineDSOGlobal("ldc.dso_dtor", registerDSO);
-  gIR->usedArray.push_back(dsoCtor);
-  gIR->usedArray.push_back(dsoDtor);
-  dsoCtor->setSection("__DATA,__mod_init_func,mod_init_funcs");
-  dsoDtor->setSection("__DATA,__mod_term_func,mod_term_funcs");
 }
 
 // Add module-private variables and functions for coverage analysis.
@@ -569,7 +393,7 @@ void registerModuleInfo(Module *m) {
     const auto miCtor = build_module_reference_and_ctor(mangle, moduleInfoSym);
     AppendFunctionToLLVMGlobalCtorsDtors(miCtor, 65535, true);
   } else {
-    emitModuleRefToSection(style, mangle, moduleInfoSym);
+    emitModuleRefToSection(mangle, moduleInfoSym);
   }
 }
 }

diff --git a/runtime/CMakeLists.txt b/runtime/CMakeLists.txt
@@ -424,7 +424,7 @@ macro(dc src_files src_basedir d_flags output_basedir emit_bc all_at_once single
             set(renameCommand "")
             if(${emit_bc})
                 # rename generated *.bc to *.bc.o[bj]
-                set(renameCommand mv ${output_basedir}/${output_root}.bc ${output_bc})
+                set(renameCommand ${CMAKE_COMMAND} -E rename ${output_basedir}/${output_root}.bc ${output_bc})
                 list(APPEND outfiles ${output_bc})
             endif()
 
@@ -461,7 +461,7 @@ macro(dc src_files src_basedir d_flags output_basedir emit_bc all_at_once single
             string(REGEX REPLACE "${CMAKE_C_OUTPUT_EXTENSION}$" "" src_bc "${dst_bc}")
             add_custom_command(
                 OUTPUT ${new_o} ${new_bc} APPEND
-                COMMAND mv ${src_bc} ${dst_bc}
+                COMMAND ${CMAKE_COMMAND} -E rename ${src_bc} ${dst_bc}
             )
         endforeach()
     endif()
@@ -506,29 +506,6 @@ macro(compile_druntime d_flags lib_suffix path_suffix emit_bc all_at_once single
     )
 endmacro()
 
-set(dso_windows_o "")
-if("${TARGET_SYSTEM}" MATCHES "Windows")
-    # Windows: precompile rt.dso_windows object file & install to lib dir.
-    # The existing object file isn't reused to prevent *exported* symbols (only
-    # -link-defaultlib-shared for dllimport, no -fvisibility=public).
-    # This allows to create executables with -link-defaultlib-shared without
-    # any exports (and according extra linker files such as the import .lib).
-    set(dso_windows_bc "")
-    dc("${RUNTIME_DIR}/src/rt/dso_windows.d"
-       "${RUNTIME_DIR}/src"
-       "-conf=;${D_FLAGS};${D_FLAGS_RELEASE};-link-defaultlib-shared;${DRUNTIME_EXTRA_FLAGS};-I${RUNTIME_DIR}/src"
-       "${CMAKE_BINARY_DIR}/lib${LIB_SUFFIX}"
-       "OFF" # emit_bc
-       "ON"  # all_at_once
-       "dso_windows" # single_obj_name
-       dso_windows_o
-       dso_windows_bc
-    )
-
-    add_custom_target(dso_windows DEPENDS ${dso_windows_o})
-    install(FILES ${dso_windows_o} DESTINATION ${CMAKE_INSTALL_PREFIX}/lib${LIB_SUFFIX})
-endif()
-
 # Sets up the targets for building the Phobos D object files, appending the
 # names of the (bitcode) files to link into the library to outlist_o (outlist_bc).
 macro(compile_phobos2 d_flags lib_suffix path_suffix emit_bc all_at_once single_obj outlist_o outlist_bc)
@@ -763,6 +740,8 @@ macro(build_runtime_variant d_flags c_flags ld_flags lib_suffix path_suffix emit
                          "${lib_suffix}${SHARED_LIB_SUFFIX}" "${path_suffix}"
                          "OFF" "${all_d_files_at_once}" "OFF" druntime_o druntime_bc)
 
+        set(rt_dso_o "${PROJECT_BINARY_DIR}/objects${target_suffix}/rt/dso${CMAKE_C_OUTPUT_EXTENSION}")
+
         # compile Phobos with public visibility (and preferably to a single object file)
         if(phobos2_common STREQUAL "")
             set(phobos2_o "")
@@ -772,19 +751,30 @@ macro(build_runtime_variant d_flags c_flags ld_flags lib_suffix path_suffix emit
                             "OFF" "${all_d_files_at_once}" "${all_d_files_at_once}" phobos2_o phobos2_bc)
         endif()
 
-        if("${TARGET_SYSTEM}" MATCHES "Windows")
-            # also link-in special rt.dso_windows druntime module
-            list(APPEND phobos2_o ${dso_windows_o})
-        endif()
+        # also link-in special rt.dso druntime module
+        list(APPEND phobos2_o ${rt_dso_o})
 
         build_runtime_libs("${druntime_o}" "${druntime_bc}" "${phobos2_o}" "${phobos2_bc}"
                            "${c_flags}" "${ld_flags}" "${lib_suffix}${SHARED_LIB_SUFFIX}" "${path_suffix}"
                            "ON" "OFF" ${outlist_targets})
 
         if(NOT phobos2_common STREQUAL "")
             add_dependencies(phobos2-ldc${target_suffix} ${phobos2_common})
-        elseif("${TARGET_SYSTEM}" MATCHES "Windows")
-            add_dependencies(phobos2-ldc${target_suffix} dso_windows)
+        endif()
+
+        if("${lib_suffix}" STREQUAL "") # non-debug & non-unittest
+            # copy rt.dso to `ldc_rt.dso.o[bj]` in lib dir
+            add_custom_command(
+                TARGET druntime-ldc${target_suffix}
+                POST_BUILD COMMAND
+                ${CMAKE_COMMAND} -E copy ${rt_dso_o} ${CMAKE_BINARY_DIR}/lib${path_suffix}/ldc_rt.dso${CMAKE_C_OUTPUT_EXTENSION}
+            )
+            # and install it too
+            install(
+                FILES ${rt_dso_o}
+                DESTINATION ${CMAKE_INSTALL_PREFIX}/lib${path_suffix}
+                RENAME ldc_rt.dso${CMAKE_C_OUTPUT_EXTENSION}
+            )
         endif()
     endif()
 endmacro()
@@ -1030,9 +1020,9 @@ macro(compile_testrunner d_flags is_shared target_suffix extra_dir_suffix)
        test_runner_bc
     )
 
-    if("${is_shared}" STREQUAL "ON" AND "${TARGET_SYSTEM}" MATCHES "Windows")
-        # also link-in special rt.dso_windows druntime module
-        list(APPEND test_runner_o ${dso_windows_o})
+    if("${is_shared}" STREQUAL "ON")
+        # also link-in special rt.dso druntime module
+        list(APPEND test_runner_o ${PROJECT_BINARY_DIR}/objects-unittest${target_suffix}/rt/dso${CMAKE_C_OUTPUT_EXTENSION})
     endif()
 endmacro()
 
@@ -1167,8 +1157,8 @@ endmacro()
 
 function(add_tests d_files runner target_suffix)
     foreach(file ${d_files})
-        # skip rt.dso_* (no ModuleInfo)
-        if(NOT "${file}" MATCHES "druntime/src/rt/dso_")
+        # skip rt.dso (no ModuleInfo)
+        if(NOT "${file}" MATCHES "druntime/src/rt/dso.d")
             file_to_module_name(${file} module)
             add_test(NAME "${module}${target_suffix}"
                 WORKING_DIRECTORY "${PROJECT_BINARY_DIR}"

diff --git a/runtime/druntime b/runtime/druntime
diff --git a/tests/codegen/ctor_initarray_gh2883.d b/tests/codegen/ctor_initarray_gh2883.d
@@ -8,4 +8,8 @@
 // CHECK: .section  .init_array
 // CHECK: .section  .fini_array
 
-// No code needed to generate asm for a module.
+pragma(crt_constructor)
+void ctor() {}
+
+pragma(crt_destructor)
+void dtor() {}
diff --git a/tests/codegen/llvm_used_1.d b/tests/codegen/llvm_used_1.d
@@ -8,9 +8,9 @@
 // RUN: %ldc -O3 %S/inputs/module_ctor.d -run %s | FileCheck --check-prefix=EXECUTE %s
 
 // There was a bug where llvm.used was emitted more than once, whose symptom was that suffixed versions would appear: e.g. `@llvm.used.3`.
-// Expect 4 llvm.used entries - 2 ModuleInfos refs + ldc.dso_{c,d}tor refs.
+// Expect 2 llvm.used entries, for both ModuleInfo refs.
 // LLVM-NOT: @llvm.used.
-// LLVM: @llvm.used = appending global [4 x i8*]
+// LLVM: @llvm.used = appending global [2 x i8*]
 // LLVM-NOT: @llvm.used.
 
 // EXECUTE: ctor
+139 −0		src/rt/dso.d
+0 −104		src/rt/dso_windows.d
+5 −5		src/rt/sections_elf_shared.d
+1 −1		test/common.mak