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mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 20:23:11 +01:00
llvm-mirror/tools/lli/lli.cpp
Lang Hames c0cf59d6e5 [ORC] Refactor OrcRemoteTarget code to expose its RPC API, reduce
code duplication in the client, and improve error propagation.

This patch moves the OrcRemoteTarget rpc::Function declarations from
OrcRemoteTargetRPCAPI into their own namespaces under llvm::orc::remote so that
they can be used in new contexts (in particular, a remote-object-file adapter
layer that I will commit shortly).

Code duplication in OrcRemoteTargetClient (especially in loops processing the
code, rw-data and ro-data allocations) is removed by moving the loop bodies
into their own functions.

Error propagation is (slightly) improved by adding an ErrorReporter functor to
the OrcRemoteTargetClient -- Errors that can't be returned (because they occur
in destructors, or behind stable APIs that don't provide error returns) can be
sent to the ErrorReporter instead. Some methods in the Client API are also
changed to make better use of the Expected class: returning Expected<T>s rather
than returning Errors and taking T&s to store the results.

llvm-svn: 312500
2017-09-04 20:54:46 +00:00

707 lines
24 KiB
C++

//===- lli.cpp - LLVM Interpreter / Dynamic compiler ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This utility provides a simple wrapper around the LLVM Execution Engines,
// which allow the direct execution of LLVM programs through a Just-In-Time
// compiler, or through an interpreter if no JIT is available for this platform.
//
//===----------------------------------------------------------------------===//
#include "OrcLazyJIT.h"
#include "RemoteJITUtils.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/CodeGen/LinkAllCodegenComponents.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/ExecutionEngine/Interpreter.h"
#include "llvm/ExecutionEngine/JITEventListener.h"
#include "llvm/ExecutionEngine/MCJIT.h"
#include "llvm/ExecutionEngine/ObjectCache.h"
#include "llvm/ExecutionEngine/Orc/OrcRemoteTargetClient.h"
#include "llvm/ExecutionEngine/OrcMCJITReplacement.h"
#include "llvm/ExecutionEngine/SectionMemoryManager.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/TypeBuilder.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Memory.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/PluginLoader.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Instrumentation.h"
#include <cerrno>
#ifdef __CYGWIN__
#include <cygwin/version.h>
#if defined(CYGWIN_VERSION_DLL_MAJOR) && CYGWIN_VERSION_DLL_MAJOR<1007
#define DO_NOTHING_ATEXIT 1
#endif
#endif
using namespace llvm;
#define DEBUG_TYPE "lli"
namespace {
enum class JITKind { MCJIT, OrcMCJITReplacement, OrcLazy };
cl::opt<std::string>
InputFile(cl::desc("<input bitcode>"), cl::Positional, cl::init("-"));
cl::list<std::string>
InputArgv(cl::ConsumeAfter, cl::desc("<program arguments>..."));
cl::opt<bool> ForceInterpreter("force-interpreter",
cl::desc("Force interpretation: disable JIT"),
cl::init(false));
cl::opt<JITKind> UseJITKind("jit-kind",
cl::desc("Choose underlying JIT kind."),
cl::init(JITKind::MCJIT),
cl::values(
clEnumValN(JITKind::MCJIT, "mcjit",
"MCJIT"),
clEnumValN(JITKind::OrcMCJITReplacement,
"orc-mcjit",
"Orc-based MCJIT replacement"),
clEnumValN(JITKind::OrcLazy,
"orc-lazy",
"Orc-based lazy JIT.")));
// The MCJIT supports building for a target address space separate from
// the JIT compilation process. Use a forked process and a copying
// memory manager with IPC to execute using this functionality.
cl::opt<bool> RemoteMCJIT("remote-mcjit",
cl::desc("Execute MCJIT'ed code in a separate process."),
cl::init(false));
// Manually specify the child process for remote execution. This overrides
// the simulated remote execution that allocates address space for child
// execution. The child process will be executed and will communicate with
// lli via stdin/stdout pipes.
cl::opt<std::string>
ChildExecPath("mcjit-remote-process",
cl::desc("Specify the filename of the process to launch "
"for remote MCJIT execution. If none is specified,"
"\n\tremote execution will be simulated in-process."),
cl::value_desc("filename"), cl::init(""));
// Determine optimization level.
cl::opt<char>
OptLevel("O",
cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
"(default = '-O2')"),
cl::Prefix,
cl::ZeroOrMore,
cl::init(' '));
cl::opt<std::string>
TargetTriple("mtriple", cl::desc("Override target triple for module"));
cl::opt<std::string>
EntryFunc("entry-function",
cl::desc("Specify the entry function (default = 'main') "
"of the executable"),
cl::value_desc("function"),
cl::init("main"));
cl::list<std::string>
ExtraModules("extra-module",
cl::desc("Extra modules to be loaded"),
cl::value_desc("input bitcode"));
cl::list<std::string>
ExtraObjects("extra-object",
cl::desc("Extra object files to be loaded"),
cl::value_desc("input object"));
cl::list<std::string>
ExtraArchives("extra-archive",
cl::desc("Extra archive files to be loaded"),
cl::value_desc("input archive"));
cl::opt<bool>
EnableCacheManager("enable-cache-manager",
cl::desc("Use cache manager to save/load mdoules"),
cl::init(false));
cl::opt<std::string>
ObjectCacheDir("object-cache-dir",
cl::desc("Directory to store cached object files "
"(must be user writable)"),
cl::init(""));
cl::opt<std::string>
FakeArgv0("fake-argv0",
cl::desc("Override the 'argv[0]' value passed into the executing"
" program"), cl::value_desc("executable"));
cl::opt<bool>
DisableCoreFiles("disable-core-files", cl::Hidden,
cl::desc("Disable emission of core files if possible"));
cl::opt<bool>
NoLazyCompilation("disable-lazy-compilation",
cl::desc("Disable JIT lazy compilation"),
cl::init(false));
cl::opt<bool>
GenerateSoftFloatCalls("soft-float",
cl::desc("Generate software floating point library calls"),
cl::init(false));
ExitOnError ExitOnErr;
}
//===----------------------------------------------------------------------===//
// Object cache
//
// This object cache implementation writes cached objects to disk to the
// directory specified by CacheDir, using a filename provided in the module
// descriptor. The cache tries to load a saved object using that path if the
// file exists. CacheDir defaults to "", in which case objects are cached
// alongside their originating bitcodes.
//
class LLIObjectCache : public ObjectCache {
public:
LLIObjectCache(const std::string& CacheDir) : CacheDir(CacheDir) {
// Add trailing '/' to cache dir if necessary.
if (!this->CacheDir.empty() &&
this->CacheDir[this->CacheDir.size() - 1] != '/')
this->CacheDir += '/';
}
~LLIObjectCache() override {}
void notifyObjectCompiled(const Module *M, MemoryBufferRef Obj) override {
const std::string &ModuleID = M->getModuleIdentifier();
std::string CacheName;
if (!getCacheFilename(ModuleID, CacheName))
return;
if (!CacheDir.empty()) { // Create user-defined cache dir.
SmallString<128> dir(sys::path::parent_path(CacheName));
sys::fs::create_directories(Twine(dir));
}
std::error_code EC;
raw_fd_ostream outfile(CacheName, EC, sys::fs::F_None);
outfile.write(Obj.getBufferStart(), Obj.getBufferSize());
outfile.close();
}
std::unique_ptr<MemoryBuffer> getObject(const Module* M) override {
const std::string &ModuleID = M->getModuleIdentifier();
std::string CacheName;
if (!getCacheFilename(ModuleID, CacheName))
return nullptr;
// Load the object from the cache filename
ErrorOr<std::unique_ptr<MemoryBuffer>> IRObjectBuffer =
MemoryBuffer::getFile(CacheName, -1, false);
// If the file isn't there, that's OK.
if (!IRObjectBuffer)
return nullptr;
// MCJIT will want to write into this buffer, and we don't want that
// because the file has probably just been mmapped. Instead we make
// a copy. The filed-based buffer will be released when it goes
// out of scope.
return MemoryBuffer::getMemBufferCopy(IRObjectBuffer.get()->getBuffer());
}
private:
std::string CacheDir;
bool getCacheFilename(const std::string &ModID, std::string &CacheName) {
std::string Prefix("file:");
size_t PrefixLength = Prefix.length();
if (ModID.substr(0, PrefixLength) != Prefix)
return false;
std::string CacheSubdir = ModID.substr(PrefixLength);
#if defined(_WIN32)
// Transform "X:\foo" => "/X\foo" for convenience.
if (isalpha(CacheSubdir[0]) && CacheSubdir[1] == ':') {
CacheSubdir[1] = CacheSubdir[0];
CacheSubdir[0] = '/';
}
#endif
CacheName = CacheDir + CacheSubdir;
size_t pos = CacheName.rfind('.');
CacheName.replace(pos, CacheName.length() - pos, ".o");
return true;
}
};
// On Mingw and Cygwin, an external symbol named '__main' is called from the
// generated 'main' function to allow static initialization. To avoid linking
// problems with remote targets (because lli's remote target support does not
// currently handle external linking) we add a secondary module which defines
// an empty '__main' function.
static void addCygMingExtraModule(ExecutionEngine &EE, LLVMContext &Context,
StringRef TargetTripleStr) {
IRBuilder<> Builder(Context);
Triple TargetTriple(TargetTripleStr);
// Create a new module.
std::unique_ptr<Module> M = make_unique<Module>("CygMingHelper", Context);
M->setTargetTriple(TargetTripleStr);
// Create an empty function named "__main".
Function *Result;
if (TargetTriple.isArch64Bit()) {
Result = Function::Create(
TypeBuilder<int64_t(void), false>::get(Context),
GlobalValue::ExternalLinkage, "__main", M.get());
} else {
Result = Function::Create(
TypeBuilder<int32_t(void), false>::get(Context),
GlobalValue::ExternalLinkage, "__main", M.get());
}
BasicBlock *BB = BasicBlock::Create(Context, "__main", Result);
Builder.SetInsertPoint(BB);
Value *ReturnVal;
if (TargetTriple.isArch64Bit())
ReturnVal = ConstantInt::get(Context, APInt(64, 0));
else
ReturnVal = ConstantInt::get(Context, APInt(32, 0));
Builder.CreateRet(ReturnVal);
// Add this new module to the ExecutionEngine.
EE.addModule(std::move(M));
}
CodeGenOpt::Level getOptLevel() {
switch (OptLevel) {
default:
errs() << "lli: Invalid optimization level.\n";
exit(1);
case '0': return CodeGenOpt::None;
case '1': return CodeGenOpt::Less;
case ' ':
case '2': return CodeGenOpt::Default;
case '3': return CodeGenOpt::Aggressive;
}
llvm_unreachable("Unrecognized opt level.");
}
LLVM_ATTRIBUTE_NORETURN
static void reportError(SMDiagnostic Err, const char *ProgName) {
Err.print(ProgName, errs());
exit(1);
}
//===----------------------------------------------------------------------===//
// main Driver function
//
int main(int argc, char **argv, char * const *envp) {
sys::PrintStackTraceOnErrorSignal(argv[0]);
PrettyStackTraceProgram X(argc, argv);
atexit(llvm_shutdown); // Call llvm_shutdown() on exit.
if (argc > 1)
ExitOnErr.setBanner(std::string(argv[0]) + ": ");
// If we have a native target, initialize it to ensure it is linked in and
// usable by the JIT.
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
InitializeNativeTargetAsmParser();
cl::ParseCommandLineOptions(argc, argv,
"llvm interpreter & dynamic compiler\n");
// If the user doesn't want core files, disable them.
if (DisableCoreFiles)
sys::Process::PreventCoreFiles();
LLVMContext Context;
// Load the bitcode...
SMDiagnostic Err;
std::unique_ptr<Module> Owner = parseIRFile(InputFile, Err, Context);
Module *Mod = Owner.get();
if (!Mod)
reportError(Err, argv[0]);
if (UseJITKind == JITKind::OrcLazy) {
std::vector<std::unique_ptr<Module>> Ms;
Ms.push_back(std::move(Owner));
for (auto &ExtraMod : ExtraModules) {
Ms.push_back(parseIRFile(ExtraMod, Err, Context));
if (!Ms.back())
reportError(Err, argv[0]);
}
std::vector<std::string> Args;
Args.push_back(InputFile);
for (auto &Arg : InputArgv)
Args.push_back(Arg);
return runOrcLazyJIT(std::move(Ms), Args);
}
if (EnableCacheManager) {
std::string CacheName("file:");
CacheName.append(InputFile);
Mod->setModuleIdentifier(CacheName);
}
// If not jitting lazily, load the whole bitcode file eagerly too.
if (NoLazyCompilation) {
// Use *argv instead of argv[0] to work around a wrong GCC warning.
ExitOnError ExitOnErr(std::string(*argv) +
": bitcode didn't read correctly: ");
ExitOnErr(Mod->materializeAll());
}
std::string ErrorMsg;
EngineBuilder builder(std::move(Owner));
builder.setMArch(MArch);
builder.setMCPU(MCPU);
builder.setMAttrs(MAttrs);
if (RelocModel.getNumOccurrences())
builder.setRelocationModel(RelocModel);
if (CMModel.getNumOccurrences())
builder.setCodeModel(CMModel);
builder.setErrorStr(&ErrorMsg);
builder.setEngineKind(ForceInterpreter
? EngineKind::Interpreter
: EngineKind::JIT);
builder.setUseOrcMCJITReplacement(UseJITKind == JITKind::OrcMCJITReplacement);
// If we are supposed to override the target triple, do so now.
if (!TargetTriple.empty())
Mod->setTargetTriple(Triple::normalize(TargetTriple));
// Enable MCJIT if desired.
RTDyldMemoryManager *RTDyldMM = nullptr;
if (!ForceInterpreter) {
if (RemoteMCJIT)
RTDyldMM = new ForwardingMemoryManager();
else
RTDyldMM = new SectionMemoryManager();
// Deliberately construct a temp std::unique_ptr to pass in. Do not null out
// RTDyldMM: We still use it below, even though we don't own it.
builder.setMCJITMemoryManager(
std::unique_ptr<RTDyldMemoryManager>(RTDyldMM));
} else if (RemoteMCJIT) {
errs() << "error: Remote process execution does not work with the "
"interpreter.\n";
exit(1);
}
builder.setOptLevel(getOptLevel());
TargetOptions Options;
if (FloatABIForCalls != FloatABI::Default)
Options.FloatABIType = FloatABIForCalls;
builder.setTargetOptions(Options);
std::unique_ptr<ExecutionEngine> EE(builder.create());
if (!EE) {
if (!ErrorMsg.empty())
errs() << argv[0] << ": error creating EE: " << ErrorMsg << "\n";
else
errs() << argv[0] << ": unknown error creating EE!\n";
exit(1);
}
std::unique_ptr<LLIObjectCache> CacheManager;
if (EnableCacheManager) {
CacheManager.reset(new LLIObjectCache(ObjectCacheDir));
EE->setObjectCache(CacheManager.get());
}
// Load any additional modules specified on the command line.
for (unsigned i = 0, e = ExtraModules.size(); i != e; ++i) {
std::unique_ptr<Module> XMod = parseIRFile(ExtraModules[i], Err, Context);
if (!XMod)
reportError(Err, argv[0]);
if (EnableCacheManager) {
std::string CacheName("file:");
CacheName.append(ExtraModules[i]);
XMod->setModuleIdentifier(CacheName);
}
EE->addModule(std::move(XMod));
}
for (unsigned i = 0, e = ExtraObjects.size(); i != e; ++i) {
Expected<object::OwningBinary<object::ObjectFile>> Obj =
object::ObjectFile::createObjectFile(ExtraObjects[i]);
if (!Obj) {
// TODO: Actually report errors helpfully.
consumeError(Obj.takeError());
reportError(Err, argv[0]);
}
object::OwningBinary<object::ObjectFile> &O = Obj.get();
EE->addObjectFile(std::move(O));
}
for (unsigned i = 0, e = ExtraArchives.size(); i != e; ++i) {
ErrorOr<std::unique_ptr<MemoryBuffer>> ArBufOrErr =
MemoryBuffer::getFileOrSTDIN(ExtraArchives[i]);
if (!ArBufOrErr)
reportError(Err, argv[0]);
std::unique_ptr<MemoryBuffer> &ArBuf = ArBufOrErr.get();
Expected<std::unique_ptr<object::Archive>> ArOrErr =
object::Archive::create(ArBuf->getMemBufferRef());
if (!ArOrErr) {
std::string Buf;
raw_string_ostream OS(Buf);
logAllUnhandledErrors(ArOrErr.takeError(), OS, "");
OS.flush();
errs() << Buf;
exit(1);
}
std::unique_ptr<object::Archive> &Ar = ArOrErr.get();
object::OwningBinary<object::Archive> OB(std::move(Ar), std::move(ArBuf));
EE->addArchive(std::move(OB));
}
// If the target is Cygwin/MingW and we are generating remote code, we
// need an extra module to help out with linking.
if (RemoteMCJIT && Triple(Mod->getTargetTriple()).isOSCygMing()) {
addCygMingExtraModule(*EE, Context, Mod->getTargetTriple());
}
// The following functions have no effect if their respective profiling
// support wasn't enabled in the build configuration.
EE->RegisterJITEventListener(
JITEventListener::createOProfileJITEventListener());
EE->RegisterJITEventListener(
JITEventListener::createIntelJITEventListener());
if (!NoLazyCompilation && RemoteMCJIT) {
errs() << "warning: remote mcjit does not support lazy compilation\n";
NoLazyCompilation = true;
}
EE->DisableLazyCompilation(NoLazyCompilation);
// If the user specifically requested an argv[0] to pass into the program,
// do it now.
if (!FakeArgv0.empty()) {
InputFile = static_cast<std::string>(FakeArgv0);
} else {
// Otherwise, if there is a .bc suffix on the executable strip it off, it
// might confuse the program.
if (StringRef(InputFile).endswith(".bc"))
InputFile.erase(InputFile.length() - 3);
}
// Add the module's name to the start of the vector of arguments to main().
InputArgv.insert(InputArgv.begin(), InputFile);
// Call the main function from M as if its signature were:
// int main (int argc, char **argv, const char **envp)
// using the contents of Args to determine argc & argv, and the contents of
// EnvVars to determine envp.
//
Function *EntryFn = Mod->getFunction(EntryFunc);
if (!EntryFn) {
errs() << '\'' << EntryFunc << "\' function not found in module.\n";
return -1;
}
// Reset errno to zero on entry to main.
errno = 0;
int Result = -1;
// Sanity check use of remote-jit: LLI currently only supports use of the
// remote JIT on Unix platforms.
if (RemoteMCJIT) {
#ifndef LLVM_ON_UNIX
errs() << "Warning: host does not support external remote targets.\n"
<< " Defaulting to local execution\n";
return -1;
#else
if (ChildExecPath.empty()) {
errs() << "-remote-mcjit requires -mcjit-remote-process.\n";
exit(1);
} else if (!sys::fs::can_execute(ChildExecPath)) {
errs() << "Unable to find usable child executable: '" << ChildExecPath
<< "'\n";
return -1;
}
#endif
}
if (!RemoteMCJIT) {
// If the program doesn't explicitly call exit, we will need the Exit
// function later on to make an explicit call, so get the function now.
Constant *Exit = Mod->getOrInsertFunction("exit", Type::getVoidTy(Context),
Type::getInt32Ty(Context));
// Run static constructors.
if (!ForceInterpreter) {
// Give MCJIT a chance to apply relocations and set page permissions.
EE->finalizeObject();
}
EE->runStaticConstructorsDestructors(false);
// Trigger compilation separately so code regions that need to be
// invalidated will be known.
(void)EE->getPointerToFunction(EntryFn);
// Clear instruction cache before code will be executed.
if (RTDyldMM)
static_cast<SectionMemoryManager*>(RTDyldMM)->invalidateInstructionCache();
// Run main.
Result = EE->runFunctionAsMain(EntryFn, InputArgv, envp);
// Run static destructors.
EE->runStaticConstructorsDestructors(true);
// If the program didn't call exit explicitly, we should call it now.
// This ensures that any atexit handlers get called correctly.
if (Function *ExitF = dyn_cast<Function>(Exit)) {
std::vector<GenericValue> Args;
GenericValue ResultGV;
ResultGV.IntVal = APInt(32, Result);
Args.push_back(ResultGV);
EE->runFunction(ExitF, Args);
errs() << "ERROR: exit(" << Result << ") returned!\n";
abort();
} else {
errs() << "ERROR: exit defined with wrong prototype!\n";
abort();
}
} else {
// else == "if (RemoteMCJIT)"
// Remote target MCJIT doesn't (yet) support static constructors. No reason
// it couldn't. This is a limitation of the LLI implementation, not the
// MCJIT itself. FIXME.
// Lanch the remote process and get a channel to it.
std::unique_ptr<FDRawChannel> C = launchRemote();
if (!C) {
errs() << "Failed to launch remote JIT.\n";
exit(1);
}
// Create a remote target client running over the channel.
typedef orc::remote::OrcRemoteTargetClient MyRemote;
auto R = ExitOnErr(MyRemote::Create(*C, ExitOnErr));
// Create a remote memory manager.
auto RemoteMM = ExitOnErr(R->createRemoteMemoryManager());
// Forward MCJIT's memory manager calls to the remote memory manager.
static_cast<ForwardingMemoryManager*>(RTDyldMM)->setMemMgr(
std::move(RemoteMM));
// Forward MCJIT's symbol resolution calls to the remote.
static_cast<ForwardingMemoryManager *>(RTDyldMM)->setResolver(
orc::createLambdaResolver(
[](const std::string &Name) { return nullptr; },
[&](const std::string &Name) {
if (auto Addr = ExitOnErr(R->getSymbolAddress(Name)))
return JITSymbol(Addr, JITSymbolFlags::Exported);
return JITSymbol(nullptr);
}));
// Grab the target address of the JIT'd main function on the remote and call
// it.
// FIXME: argv and envp handling.
JITTargetAddress Entry = EE->getFunctionAddress(EntryFn->getName().str());
EE->finalizeObject();
DEBUG(dbgs() << "Executing '" << EntryFn->getName() << "' at 0x"
<< format("%llx", Entry) << "\n");
Result = ExitOnErr(R->callIntVoid(Entry));
// Like static constructors, the remote target MCJIT support doesn't handle
// this yet. It could. FIXME.
// Delete the EE - we need to tear it down *before* we terminate the session
// with the remote, otherwise it'll crash when it tries to release resources
// on a remote that has already been disconnected.
EE.reset();
// Signal the remote target that we're done JITing.
ExitOnErr(R->terminateSession());
}
return Result;
}
std::unique_ptr<FDRawChannel> launchRemote() {
#ifndef LLVM_ON_UNIX
llvm_unreachable("launchRemote not supported on non-Unix platforms");
#else
int PipeFD[2][2];
pid_t ChildPID;
// Create two pipes.
if (pipe(PipeFD[0]) != 0 || pipe(PipeFD[1]) != 0)
perror("Error creating pipe: ");
ChildPID = fork();
if (ChildPID == 0) {
// In the child...
// Close the parent ends of the pipes
close(PipeFD[0][1]);
close(PipeFD[1][0]);
// Execute the child process.
std::unique_ptr<char[]> ChildPath, ChildIn, ChildOut;
{
ChildPath.reset(new char[ChildExecPath.size() + 1]);
std::copy(ChildExecPath.begin(), ChildExecPath.end(), &ChildPath[0]);
ChildPath[ChildExecPath.size()] = '\0';
std::string ChildInStr = utostr(PipeFD[0][0]);
ChildIn.reset(new char[ChildInStr.size() + 1]);
std::copy(ChildInStr.begin(), ChildInStr.end(), &ChildIn[0]);
ChildIn[ChildInStr.size()] = '\0';
std::string ChildOutStr = utostr(PipeFD[1][1]);
ChildOut.reset(new char[ChildOutStr.size() + 1]);
std::copy(ChildOutStr.begin(), ChildOutStr.end(), &ChildOut[0]);
ChildOut[ChildOutStr.size()] = '\0';
}
char * const args[] = { &ChildPath[0], &ChildIn[0], &ChildOut[0], nullptr };
int rc = execv(ChildExecPath.c_str(), args);
if (rc != 0)
perror("Error executing child process: ");
llvm_unreachable("Error executing child process");
}
// else we're the parent...
// Close the child ends of the pipes
close(PipeFD[0][0]);
close(PipeFD[1][1]);
// Return an RPC channel connected to our end of the pipes.
return llvm::make_unique<FDRawChannel>(PipeFD[1][0], PipeFD[0][1]);
#endif
}