llvm/llvm/examples/OrcV2Examples/LLJITWithThinLTOSummaries/LLJITWithThinLTOSummaries.cpp

//===--- LLJITWithThinLTOSummaries.cpp - Module summaries as LLJIT input --===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// In this example we will use a module summary index file produced for ThinLTO
// to (A) find the module that defines the main entry point and (B) find all
// extra modules that we need. We will do this in five steps:
//
// (1) Read the index file and parse the module summary index.
// (2) Find the path of the module that defines "main".
// (3) Parse the main module and create a matching LLJIT.
// (4) Add all modules to the LLJIT that are covered by the index.
// (5) Look up and run the JIT'd function.
//
// The index file name must be passed in as command line argument. Please find
// this test for instructions on creating the index file:
//
//       llvm/test/Examples/OrcV2Examples/lljit-with-thinlto-summaries.test
//
// If you use "build" as the build directory, you can run the test from the root
// of the monorepo like this:
//
// > build/bin/llvm-lit -a \
//       llvm/test/Examples/OrcV2Examples/lljit-with-thinlto-summaries.test
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/ExecutionEngine/Orc/Core.h"
#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
#include "llvm/ExecutionEngine/Orc/LLJIT.h"
#include "llvm/ExecutionEngine/Orc/ThreadSafeModule.h"
#include "llvm/ExecutionEngine/Orc/TargetProcess/TargetExecutionUtils.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"

#include <string>
#include <system_error>
#include <vector>

usingnamespacellvm;
usingnamespacellvm::orc;

// Path of the module summary index file.
cl::opt<std::string> IndexFile{ … };

// Describe a fail state that is caused by the given ModuleSummaryIndex
// providing multiple definitions of the given global value name. It will dump
// name and GUID for the global value and list the paths of the modules covered
// by the index.
class DuplicateDefinitionInSummary
    : public ErrorInfo<DuplicateDefinitionInSummary> { … };

// Describe a fail state where the given global value name was not found in the
// given ModuleSummaryIndex. It will dump name and GUID for the global value and
// list the paths of the modules covered by the index.
class DefinitionNotFoundInSummary
    : public ErrorInfo<DefinitionNotFoundInSummary> { … };

char DuplicateDefinitionInSummary::ID = …;
char DefinitionNotFoundInSummary::ID = …;

// Lookup the a function in the ModuleSummaryIndex and return the path of the
// module that defines it. Paths in the ModuleSummaryIndex are relative to the
// build directory of the covered modules.
Expected<StringRef> getMainModulePath(StringRef FunctionName,
                                      ModuleSummaryIndex &Index) { … }

// Parse the bitcode module from the given path into a ThreadSafeModule.
Expected<ThreadSafeModule> loadModule(StringRef Path,
                                      orc::ThreadSafeContext TSCtx) { … }

int main(int Argc, char *Argv[]) { … }