llvm/lib/Plugins/PassPlugin.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "llvm/Plugins/PassPlugin.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/raw_ostream.h"

#include <cstdint>

using namespace llvm;

Expected<PassPlugin> PassPlugin::load(StringRef Filename) {
  std::string Error;
  auto Library =
      sys::DynamicLibrary::getPermanentLibrary(Filename.str().c_str(), &Error);
  if (!Library.isValid())
    return make_error<StringError>(Twine("Could not load library '") +
                                       Filename + "': " + Error,
                                   inconvertibleErrorCode());

  PassPlugin P{Filename.str(), Library};

  // llvmGetPassPluginInfo should be resolved to the definition from the plugin
  // we are currently loading.
  intptr_t getDetailsFn =
      (intptr_t)Library.getAddressOfSymbol("llvmGetPassPluginInfo");

  if (!getDetailsFn)
    // If the symbol isn't found, this is probably a legacy plugin, which is an
    // error
    return make_error<StringError>(Twine("Plugin entry point not found in '") +
                                       Filename + "'. Is this a legacy plugin?",
                                   inconvertibleErrorCode());

  P.Info = reinterpret_cast<decltype(llvmGetPassPluginInfo) *>(getDetailsFn)();

  if (P.Info.APIVersion != LLVM_PLUGIN_API_VERSION)
    return make_error<StringError>(
        Twine("Wrong API version on plugin '") + Filename + "'. Got version " +
            Twine(P.Info.APIVersion) + ", supported version is " +
            Twine(LLVM_PLUGIN_API_VERSION) + ".",
        inconvertibleErrorCode());

  return P;
}

Error llvm::passPluginArguments(ArrayRef<PassPluginLibraryInfo> Infos,
                                ArrayRef<std::string> Args) {
  DenseMap<StringRef, unsigned> Index;
  for (auto [I, Info] : enumerate(Infos))
    if (!Index.try_emplace(Info.PluginName, I).second)
      return createStringError("multiple pass plugins are named '" +
                               Twine(Info.PluginName) + "'");
  // ParseArguments takes argv-style C strings. The argument is the suffix of
  // Arg after the first comma, so it is NUL-terminated and needs no copy.
  SmallVector<SmallVector<const char *, 0>, 0> PluginArgs(Infos.size());
  for (const std::string &Arg : Args) {
    auto [Name, Rest] = StringRef(Arg).split(',');
    // Rest is null without a comma and empty for an empty argument.
    if (!Rest.data())
      return createStringError("expected <plugin>,<arg> in -plugin-arg=" + Arg);
    auto It = Index.find(Name);
    if (It == Index.end())
      return createStringError("no pass plugin named '" + Name +
                               "' is loaded, in -plugin-arg=" + Arg);
    PluginArgs[It->second].push_back(Rest.data());
  }
  for (auto [Info, PArgs] : zip_equal(Infos, PluginArgs)) {
    if (PArgs.empty())
      continue;
    if (!Info.ParseArguments)
      return createStringError("pass plugin '" + Twine(Info.PluginName) +
                               "' does not accept arguments");
    if (Error E = Info.ParseArguments(PArgs))
      return E;
  }
  return Error::success();
}