[ELF] Enable new passmanager plugin support for LTO

[jkl]

Summary

add cli options for new passmanager plugin support to lld.

Currently it is not possible to load dynamic NewPM plugins with lld.
This is an incremental update to D76866.
While that patch only added cli options for llvm-lto2, this adds them
for lld as well.
This is especially useful for running dynamic plugins
on the linux kernel with LTO.

[teemperor]

Just some drive-by comments, but in general I think this would be nice to get fixed.

lld/ELF/Config.h

150

lld/ELF/Driver.cpp

1290–1292

lld/ELF/LTO.cpp

150

llvm/test/Feature/load_extension.ll

9 ↗

(On Diff #411134)

This seems like it should be a test in lld/test instead of LLVM?

[jkl]

I guess the syntax changes depend on whether the code should be in sync with the llvm-link2 version or not.
I'll leave it as it is, to get the preference of others.

[efriedma]

Generally looks fine, barring any concerns with code style.

[jkl]

I fixed the styling changes suggested.

[MaskRay]

lld/ELF/Config.h

150

passPlugins

[MaskRay]

llvm/test/Feature/load_extension.ll

9 ↗

(On Diff #413854)

llvm/test tests cannot use ld.lld

[jkl]

With the help of @teemperor I moved the test into lld/test but since this is using the Bye pass, we had to enable that for lld.

[MaskRay]

lld/ELF/Config.h

150

Move this before std::vector<llvm::StringRef> searchPaths;

lld/ELF/LTO.cpp

150

lld/test/ELF/lto/ltopasses-extension.ll

6

We don't need legacy PM tests. It will go away soon.

[MaskRay]

lld/ELF/LTO.cpp

150

Not done: StringRef instead of StringRef &

[jkl]

sorry, my bad I missed that. Fixed now.

[MaskRay]

lld/ELF/Options.td

720

lld/test/ELF/lto/ltopasses-extension.ll

5

Don't leave output in the current directory (which may be read-only in some downstream groups)

[dyung]

This change is causing CMake failures on at least 2 different bots due to a missing dependency target "Bye". Can you take a look?

https://lab.llvm.org/buildbot/#/builders/139/builds/19115
https://lab.llvm.org/buildbot/#/builders/98/builds/15274

[teemperor]

Thanks, reverting while investigating.

lld/ELF/Config.h

struct Configuration {
   StringRef zCetReport = "none";
   llvm::StringRef ltoBasicBlockSections;
   std::pair<llvm::StringRef, llvm::StringRef> thinLTOObjectSuffixReplace;
   std::pair<llvm::StringRef, llvm::StringRef> thinLTOPrefixReplace;
   std::string rpath;
   std::vector<VersionDefinition> versionDefinitions;
   std::vector<llvm::StringRef> auxiliaryList;
   std::vector<llvm::StringRef> filterList;
+  std::vector<llvm::StringRef> passPlugins;
   std::vector<llvm::StringRef> searchPaths;
   std::vector<llvm::StringRef> symbolOrderingFile;
   std::vector<llvm::StringRef> thinLTOModulesToCompile;
   std::vector<llvm::StringRef> undefined;
   std::vector<SymbolVersion> dynamicList;
   std::vector<uint8_t> buildIdVector;
   llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>,
                   uint64_t>
       callGraphProfile;
   bool allowMultipleDefinition;
   bool androidPackDynRelocs = false;
   bool armHasBlx = false;
   bool armHasMovtMovw = false;
   bool armJ1J2BranchEncoding = false;
   bool asNeeded = false;

lld/ELF/Driver.cpp

static void readConfigs(opt::InputArgList &args) {
   // GCC collect2 passes -plugin-opt=path/to/lto-wrapper with an absolute or
   // relative path. Just ignore. If not ended with "lto-wrapper", consider it an
   // unsupported LLVMgold.so option and error.
   for (opt::Arg *arg : args.filtered(OPT_plugin_opt_eq))
     if (!StringRef(arg->getValue()).endswith("lto-wrapper"))
       error(arg->getSpelling() + ": unknown plugin option '" + arg->getValue() +
             "'");
 
+  config->passPlugins = args::getStrings(args, OPT_load_pass_plugins);
+
   // Parse -mllvm options.
   for (auto *arg : args.filtered(OPT_mllvm))
     parseClangOption(arg->getValue(), arg->getSpelling());
 
   // --threads= takes a positive integer and provides the default value for
   // --thinlto-jobs=.
   if (auto *arg = args.getLastArg(OPT_threads)) {
     StringRef v(arg->getValue());
     unsigned threads = 0;

lld/ELF/LTO.cpp

static lto::Config createConfig() {
   c.RemarksHotnessThreshold = config->optRemarksHotnessThreshold;
   c.RemarksFormat = std::string(config->optRemarksFormat);
 
   // Set up output file to emit statistics.
   c.StatsFile = std::string(config->optStatsFilename);
 
   c.SampleProfile = std::string(config->ltoSampleProfile);
   c.UseNewPM = config->ltoNewPassManager;
+  for (StringRef pluginFn : config->passPlugins)
+    c.PassPlugins.push_back(std::string(pluginFn));
   c.DebugPassManager = config->ltoDebugPassManager;
   c.DwoDir = std::string(config->dwoDir);
 
   c.HasWholeProgramVisibility = config->ltoWholeProgramVisibility;
   c.AlwaysEmitRegularLTOObj = !config->ltoObjPath.empty();
 
   for (const llvm::StringRef &name : config->thinLTOModulesToCompile)
     c.ThinLTOModulesToCompile.emplace_back(name);

lld/ELF/Options.td

defm mips_got_size:
   Eq<"mips-got-size", "Max size of a single MIPS GOT. 0x10000 by default.">,
   Flags<[HelpHidden]>;
 
 // Hidden option used to opt-in to additional output checks.
 defm check_dynamic_relocations: BB<"check-dynamic-relocations",
     "Perform additional validation of the written dynamic relocations",
     "Do not perform additional validation of the written dynamic relocations">,
   Flags<[HelpHidden]>;
+
+defm load_pass_plugins: EEq<"load-pass-plugin", "Load passes from plugin library">;

lld/test/CMakeLists.txt

 if (CMAKE_CFG_INTDIR STREQUAL ".")
   set(LLVM_BUILD_MODE ".")
 else ()
   set(LLVM_BUILD_MODE "%(build_mode)s")
 endif ()
 
 string(REPLACE "${CMAKE_CFG_INTDIR}" "${LLVM_BUILD_MODE}" LLD_LIBS_DIR "${LLVM_LIBRARY_OUTPUT_INTDIR}")
 string(REPLACE "${CMAKE_CFG_INTDIR}" "${LLVM_BUILD_MODE}" LLD_TOOLS_DIR "${LLVM_RUNTIME_OUTPUT_INTDIR}")
 
 llvm_canonicalize_cmake_booleans(
   LLVM_ENABLE_ZLIB
   LLVM_ENABLE_LIBXML2
   LLD_DEFAULT_LD_LLD_IS_MINGW
   LLVM_HAVE_LIBXAR
+  LLVM_BUILD_EXAMPLES
+  LLVM_ENABLE_PLUGINS
+  LLVM_BYE_LINK_INTO_TOOLS
   )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
   )
list(APPEND LLD_TEST_DEPS
     llvm-strip
     llvm-symbolizer
     not
     obj2yaml
     opt
     split-file
     yaml2obj
     )
+    if (NOT WIN32)
+      list(APPEND LLD_TEST_DEPS
+        Bye
+        )
+    endif()
 endif()
 
 add_lit_testsuite(check-lld "Running lld test suite"
   ${CMAKE_CURRENT_BINARY_DIR}
   DEPENDS ${LLD_TEST_DEPS}
   )
 
 add_custom_target(lld-test-depends DEPENDS ${LLD_TEST_DEPS})

lld/test/ELF/lto/ltopasses-extension.ll

+; REQUIRES: x86, plugins, examples
+; UNSUPPORTED: windows
+; RUN: opt -module-summary %s -o %t.o
+; RUN: ld.lld -%loadnewpmbye --lto-newpm-passes="goodbye" -mllvm=%loadbye -mllvm=-wave-goodbye %t.o -o /dev/null 2>&1 | FileCheck %s
+; CHECK: Bye
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+@junk = global i32 0
+
+define i32* @somefunk() {
+  ret i32* @junk
+}

lld/test/lit.cfg.py

if config.have_libxml2:
     config.available_features.add('libxml2')
 
 if config.have_dia_sdk:
     config.available_features.add("diasdk")
 
 if config.sizeof_void_p == 8:
     config.available_features.add("llvm-64-bits")
 
+if config.has_plugins:
+    config.available_features.add('plugins')
+
+if config.build_examples:
+    config.available_features.add('examples')
+
+if config.linked_bye_extension:
+    config.substitutions.append(('%loadbye', ''))
+    config.substitutions.append(('%loadnewpmbye', ''))
+else:
+    config.substitutions.append(('%loadbye',
+                                 '-load={}/Bye{}'.format(config.llvm_shlib_dir,
+                                                         config.llvm_shlib_ext)))
+    config.substitutions.append(('%loadnewpmbye',
+                                 '-load-pass-plugin={}/Bye{}'
+                                 .format(config.llvm_shlib_dir,
+                                         config.llvm_shlib_ext)))
+
 tar_executable = lit.util.which('tar', config.environment['PATH'])
 if tar_executable:
     env = os.environ
     env['LANG'] = 'C'
     tar_version = subprocess.Popen(
         [tar_executable, '--version'],
         stdout=subprocess.PIPE,
         stderr=subprocess.PIPE,
         env=env)
     sout, _ = tar_version.communicate()
     if 'GNU tar' in sout.decode():
         config.available_features.add('gnutar')
 
 # ELF tests expect the default target for ld.lld to be ELF.
 if config.ld_lld_default_mingw:
     config.excludes.append('ELF')

lld/test/lit.site.cfg.py.in

 @LIT_SITE_CFG_IN_HEADER@
 
 import lit.util
 
 config.have_dia_sdk = lit.util.pythonize_bool("@LLVM_ENABLE_DIA_SDK@")
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
 config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
 config.llvm_libs_dir = lit_config.substitute("@LLVM_LIBS_DIR@")
+config.llvm_shlib_dir = "@SHLIBDIR@"
+config.llvm_shlib_ext = "@SHLIBEXT@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.errc_messages = "@LLVM_LIT_ERRC_MESSAGES@"
 config.lld_obj_root = "@LLD_BINARY_DIR@"
 config.lld_libs_dir = lit_config.substitute("@LLD_LIBS_DIR@")
 config.lld_tools_dir = lit_config.substitute("@LLD_TOOLS_DIR@")
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.have_libxar = @LLVM_HAVE_LIBXAR@
 config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
 config.ld_lld_default_mingw = @LLD_DEFAULT_LD_LLD_IS_MINGW@
+config.build_examples = @LLVM_BUILD_EXAMPLES@
+config.has_plugins = @LLVM_ENABLE_PLUGINS@
+config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
 
 import lit.llvm
 lit.llvm.initialize(lit_config, config)
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@LLD_SOURCE_DIR@/test/lit.cfg.py")

llvm/examples/Bye/Bye.cpp

static RegisterPass<LegacyBye> X("goodbye", "Good Bye World Pass",
                                  false /* Analysis Pass */);
 
 /* Legacy PM Registration */
 static llvm::RegisterStandardPasses RegisterBye(
     llvm::PassManagerBuilder::EP_VectorizerStart,
     [](const llvm::PassManagerBuilder &Builder,
        llvm::legacy::PassManagerBase &PM) { PM.add(new LegacyBye()); });
 
+static llvm::RegisterStandardPasses RegisterByeLTO(
+    llvm::PassManagerBuilder::EP_ModuleOptimizerEarly,
+    [](const llvm::PassManagerBuilder &Builder,
+       llvm::legacy::PassManagerBase &PM) { PM.add(new LegacyBye()); });
+
 /* New PM Registration */
 llvm::PassPluginLibraryInfo getByePluginInfo() {
   return {LLVM_PLUGIN_API_VERSION, "Bye", LLVM_VERSION_STRING,
           [](PassBuilder &PB) {
             PB.registerVectorizerStartEPCallback(
                 [](llvm::FunctionPassManager &PM, OptimizationLevel Level) {
                   PM.addPass(Bye());
                 });