Files
clang-p2996/lldb/source/Host/windows/Host.cpp
Pavel Labath 62930e57eb Add Utility/Environment class for handling... environments
Summary:
There was some confusion in the code about how to represent process
environment. Most of the code (ab)used the Args class for this purpose,
but some of it used a more basic StringList class instead. In either
case, the fact that the underlying abstraction did not provide primitive
operations for the typical environment operations meant that even a
simple operation like checking for an environment variable value was
several lines of code.

This patch adds a separate Environment class, which is essentialy a
llvm::StringMap<std::string> in disguise. To standard StringMap
functionality, it adds a couple of new functions, which are specific to
the environment use case:
- (most important) envp conversion for passing into execve() and likes.
  Instead of trying to maintain a constantly up-to-date envp view, it
  provides a function which creates a envp view on demand, with the
  expectation that this will be called as the very last thing before
  handing the value to the system function.
- insert(StringRef KeyEqValue) - splits KeyEqValue into (key, value)
  pair and inserts it into the environment map.
- compose(value_type KeyValue) - takes a map entry and converts in back
  into "KEY=VALUE" representation.

With this interface most of the environment-manipulating code becomes
one-liners. The only tricky part was maintaining compatibility in
SBLaunchInfo, which expects that the environment entries are accessible
by index and that the returned const char* is backed by the launch info
object (random access into maps is hard and the map stores the entry in
a deconstructed form, so we cannot just return a .c_str() value). To
solve this, I have the SBLaunchInfo convert the environment into the
"envp" form, and use it to answer the environment queries. Extra code is
added to make sure the envp version is always in sync.

(This also improves the layering situation as Args was in the Interpreter module
whereas Environment is in Utility.)

Reviewers: zturner, davide, jingham, clayborg

Subscribers: emaste, lldb-commits, mgorny

Differential Revision: https://reviews.llvm.org/D41359

llvm-svn: 322174
2018-01-10 11:57:31 +00:00

281 lines
8.9 KiB
C++

//===-- source/Host/windows/Host.cpp ----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
#include "lldb/Host/windows/AutoHandle.h"
#include "lldb/Host/windows/windows.h"
#include <stdio.h>
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Host/Host.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "lldb/Utility/DataExtractor.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/StructuredData.h"
#include "llvm/Support/ConvertUTF.h"
// Windows includes
#include <tlhelp32.h>
using namespace lldb;
using namespace lldb_private;
namespace {
bool GetTripleForProcess(const FileSpec &executable, llvm::Triple &triple) {
// Open the PE File as a binary file, and parse just enough information to
// determine the
// machine type.
File imageBinary(executable.GetPath().c_str(), File::eOpenOptionRead,
lldb::eFilePermissionsUserRead);
imageBinary.SeekFromStart(0x3c);
int32_t peOffset = 0;
uint32_t peHead = 0;
uint16_t machineType = 0;
size_t readSize = sizeof(peOffset);
imageBinary.Read(&peOffset, readSize);
imageBinary.SeekFromStart(peOffset);
imageBinary.Read(&peHead, readSize);
if (peHead != 0x00004550) // "PE\0\0", little-endian
return false; // Status: Can't find PE header
readSize = 2;
imageBinary.Read(&machineType, readSize);
triple.setVendor(llvm::Triple::PC);
triple.setOS(llvm::Triple::Win32);
triple.setArch(llvm::Triple::UnknownArch);
if (machineType == 0x8664)
triple.setArch(llvm::Triple::x86_64);
else if (machineType == 0x14c)
triple.setArch(llvm::Triple::x86);
return true;
}
bool GetExecutableForProcess(const AutoHandle &handle, std::string &path) {
// Get the process image path. MAX_PATH isn't long enough, paths can actually
// be up to 32KB.
std::vector<wchar_t> buffer(PATH_MAX);
DWORD dwSize = buffer.size();
if (!::QueryFullProcessImageNameW(handle.get(), 0, &buffer[0], &dwSize))
return false;
return llvm::convertWideToUTF8(buffer.data(), path);
}
void GetProcessExecutableAndTriple(const AutoHandle &handle,
ProcessInstanceInfo &process) {
// We may not have permissions to read the path from the process. So start
// off by
// setting the executable file to whatever Toolhelp32 gives us, and then try
// to
// enhance this with more detailed information, but fail gracefully.
std::string executable;
llvm::Triple triple;
triple.setVendor(llvm::Triple::PC);
triple.setOS(llvm::Triple::Win32);
triple.setArch(llvm::Triple::UnknownArch);
if (GetExecutableForProcess(handle, executable)) {
FileSpec executableFile(executable.c_str(), false);
process.SetExecutableFile(executableFile, true);
GetTripleForProcess(executableFile, triple);
}
process.SetArchitecture(ArchSpec(triple));
// TODO(zturner): Add the ability to get the process user name.
}
}
lldb::thread_t Host::GetCurrentThread() {
return lldb::thread_t(::GetCurrentThread());
}
void Host::Kill(lldb::pid_t pid, int signo) {
TerminateProcess((HANDLE)pid, 1);
}
const char *Host::GetSignalAsCString(int signo) { return NULL; }
FileSpec Host::GetModuleFileSpecForHostAddress(const void *host_addr) {
FileSpec module_filespec;
HMODULE hmodule = NULL;
if (!::GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
(LPCTSTR)host_addr, &hmodule))
return module_filespec;
std::vector<wchar_t> buffer(PATH_MAX);
DWORD chars_copied = 0;
do {
chars_copied = ::GetModuleFileNameW(hmodule, &buffer[0], buffer.size());
if (chars_copied == buffer.size() &&
::GetLastError() == ERROR_INSUFFICIENT_BUFFER)
buffer.resize(buffer.size() * 2);
} while (chars_copied >= buffer.size());
std::string path;
if (!llvm::convertWideToUTF8(buffer.data(), path))
return module_filespec;
module_filespec.SetFile(path, false);
return module_filespec;
}
uint32_t Host::FindProcesses(const ProcessInstanceInfoMatch &match_info,
ProcessInstanceInfoList &process_infos) {
process_infos.Clear();
AutoHandle snapshot(CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0));
if (!snapshot.IsValid())
return 0;
PROCESSENTRY32W pe = {};
pe.dwSize = sizeof(PROCESSENTRY32W);
if (Process32FirstW(snapshot.get(), &pe)) {
do {
AutoHandle handle(::OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE,
pe.th32ProcessID),
nullptr);
ProcessInstanceInfo process;
std::string exeFile;
llvm::convertWideToUTF8(pe.szExeFile, exeFile);
process.SetExecutableFile(FileSpec(exeFile, false), true);
process.SetProcessID(pe.th32ProcessID);
process.SetParentProcessID(pe.th32ParentProcessID);
GetProcessExecutableAndTriple(handle, process);
if (match_info.MatchAllProcesses() || match_info.Matches(process))
process_infos.Append(process);
} while (Process32NextW(snapshot.get(), &pe));
}
return process_infos.GetSize();
}
bool Host::GetProcessInfo(lldb::pid_t pid, ProcessInstanceInfo &process_info) {
process_info.Clear();
AutoHandle handle(
::OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, pid),
nullptr);
if (!handle.IsValid())
return false;
process_info.SetProcessID(pid);
GetProcessExecutableAndTriple(handle, process_info);
// Need to read the PEB to get parent process and command line arguments.
return true;
}
HostThread Host::StartMonitoringChildProcess(
const Host::MonitorChildProcessCallback &callback, lldb::pid_t pid,
bool monitor_signals) {
return HostThread();
}
Status Host::ShellExpandArguments(ProcessLaunchInfo &launch_info) {
Status error;
if (launch_info.GetFlags().Test(eLaunchFlagShellExpandArguments)) {
FileSpec expand_tool_spec;
if (!HostInfo::GetLLDBPath(lldb::ePathTypeSupportExecutableDir,
expand_tool_spec)) {
error.SetErrorString("could not find support executable directory for "
"the lldb-argdumper tool");
return error;
}
expand_tool_spec.AppendPathComponent("lldb-argdumper.exe");
if (!expand_tool_spec.Exists()) {
error.SetErrorString("could not find the lldb-argdumper tool");
return error;
}
std::string quoted_cmd_string;
launch_info.GetArguments().GetQuotedCommandString(quoted_cmd_string);
std::replace(quoted_cmd_string.begin(), quoted_cmd_string.end(), '\\', '/');
StreamString expand_command;
expand_command.Printf("\"%s\" %s", expand_tool_spec.GetPath().c_str(),
quoted_cmd_string.c_str());
int status;
std::string output;
std::string command = expand_command.GetString();
RunShellCommand(command.c_str(), launch_info.GetWorkingDirectory(), &status,
nullptr, &output, 10);
if (status != 0) {
error.SetErrorStringWithFormat("lldb-argdumper exited with error %d",
status);
return error;
}
auto data_sp = StructuredData::ParseJSON(output);
if (!data_sp) {
error.SetErrorString("invalid JSON");
return error;
}
auto dict_sp = data_sp->GetAsDictionary();
if (!data_sp) {
error.SetErrorString("invalid JSON");
return error;
}
auto args_sp = dict_sp->GetObjectForDotSeparatedPath("arguments");
if (!args_sp) {
error.SetErrorString("invalid JSON");
return error;
}
auto args_array_sp = args_sp->GetAsArray();
if (!args_array_sp) {
error.SetErrorString("invalid JSON");
return error;
}
launch_info.GetArguments().Clear();
for (size_t i = 0; i < args_array_sp->GetSize(); i++) {
auto item_sp = args_array_sp->GetItemAtIndex(i);
if (!item_sp)
continue;
auto str_sp = item_sp->GetAsString();
if (!str_sp)
continue;
launch_info.GetArguments().AppendArgument(str_sp->GetValue());
}
}
return error;
}
Environment Host::GetEnvironment() {
Environment env;
// The environment block on Windows is a contiguous buffer of NULL terminated
// strings, where the end of the environment block is indicated by two
// consecutive NULLs.
LPWCH environment_block = ::GetEnvironmentStringsW();
while (*environment_block != L'\0') {
std::string current_var;
auto current_var_size = wcslen(environment_block) + 1;
if (!llvm::convertWideToUTF8(environment_block, current_var)) {
environment_block += current_var_size;
continue;
}
if (current_var[0] != '=')
env.insert(current_var);
environment_block += current_var_size;
}
return env;
}