Files
llvm/lldb/source/API/SBStream.cpp
John Harrison bb9df2e3bd [lldb] Ensure FILE* access mode is correctly specified when creating a NativeFile. (#167764)
If we open a `NativeFile` with a `FILE*`, the OpenOptions default to
`eOpenOptionReadOnly`. This is an issue in python scripts if you try to
write to one of the files like `print("Hi",
file=lldb.debugger.GetOutputFileHandle())`.

To address this, we need to specify the access mode whenever we create a
`NativeFile` from a `FILE*`. I also added an assert on the `NativeFile`
that validates the file is opened with the correct access mode and
updated `NativeFile::Read` and `NativeFile::Write` to check the access
mode.

Before these changes:
```
$ lldb -b -O 'script lldb.debugger.GetOutputFileHandle().write("abc")'
(lldb) script lldb.debugger.GetOutputFileHandle().write("abc")
Traceback (most recent call last):
  File "<input>", line 1, in <module>
io.UnsupportedOperation: not writable
```

After:
```
$ lldb -b -O 'script lldb.debugger.GetOutputFileHandle().write("abc")'
(lldb) script lldb.debugger.GetOutputFileHandle().write("abc")
abc3
```

Fixes #122387
2025-11-17 10:51:13 -08:00

196 lines
5.7 KiB
C++

//===-- SBStream.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 "lldb/API/SBStream.h"
#include "lldb/API/SBFile.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/StreamFile.h"
#include "lldb/Utility/Instrumentation.h"
#include "lldb/Utility/LLDBLog.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/Stream.h"
#include "lldb/Utility/StreamString.h"
using namespace lldb;
using namespace lldb_private;
SBStream::SBStream() : m_opaque_up(new StreamString()) {
LLDB_INSTRUMENT_VA(this);
}
SBStream::SBStream(SBStream &&rhs)
: m_opaque_up(std::move(rhs.m_opaque_up)), m_is_file(rhs.m_is_file) {}
SBStream::~SBStream() = default;
bool SBStream::IsValid() const {
LLDB_INSTRUMENT_VA(this);
return this->operator bool();
}
SBStream::operator bool() const {
LLDB_INSTRUMENT_VA(this);
return (m_opaque_up != nullptr);
}
// If this stream is not redirected to a file, it will maintain a local cache
// for the stream data which can be accessed using this accessor.
const char *SBStream::GetData() {
LLDB_INSTRUMENT_VA(this);
if (m_is_file || m_opaque_up == nullptr)
return nullptr;
return ConstString(static_cast<StreamString *>(m_opaque_up.get())->GetData())
.GetCString();
}
// If this stream is not redirected to a file, it will maintain a local cache
// for the stream output whose length can be accessed using this accessor.
size_t SBStream::GetSize() {
LLDB_INSTRUMENT_VA(this);
if (m_is_file || m_opaque_up == nullptr)
return 0;
return static_cast<StreamString *>(m_opaque_up.get())->GetSize();
}
void SBStream::Print(const char *str) {
LLDB_INSTRUMENT_VA(this, str);
Printf("%s", str);
}
void SBStream::Printf(const char *format, ...) {
if (!format)
return;
va_list args;
va_start(args, format);
ref().PrintfVarArg(format, args);
va_end(args);
}
void SBStream::RedirectToFile(const char *path, bool append) {
LLDB_INSTRUMENT_VA(this, path, append);
if (path == nullptr)
return;
std::string local_data;
if (m_opaque_up) {
// See if we have any locally backed data. If so, copy it so we can then
// redirect it to the file so we don't lose the data
if (!m_is_file)
local_data = std::string(
static_cast<StreamString *>(m_opaque_up.get())->GetString());
}
auto open_options = File::eOpenOptionWriteOnly | File::eOpenOptionCanCreate;
if (append)
open_options |= File::eOpenOptionAppend;
else
open_options |= File::eOpenOptionTruncate;
llvm::Expected<FileUP> file =
FileSystem::Instance().Open(FileSpec(path), open_options);
if (!file) {
LLDB_LOG_ERROR(GetLog(LLDBLog::API), file.takeError(),
"Cannot open {1}: {0}", path);
return;
}
m_opaque_up = std::make_unique<StreamFile>(std::move(file.get()));
m_is_file = true;
// If we had any data locally in our StreamString, then pass that along to
// the to new file we are redirecting to.
if (!local_data.empty())
m_opaque_up->Write(&local_data[0], local_data.size());
}
void SBStream::RedirectToFileHandle(FILE *fh, bool transfer_fh_ownership) {
LLDB_INSTRUMENT_VA(this, fh, transfer_fh_ownership);
FileSP file = std::make_unique<NativeFile>(fh, File::eOpenOptionReadWrite,
transfer_fh_ownership);
return RedirectToFile(file);
}
void SBStream::RedirectToFile(SBFile file) {
LLDB_INSTRUMENT_VA(this, file)
RedirectToFile(file.GetFile());
}
void SBStream::RedirectToFile(FileSP file_sp) {
LLDB_INSTRUMENT_VA(this, file_sp);
if (!file_sp || !file_sp->IsValid())
return;
std::string local_data;
if (m_opaque_up) {
// See if we have any locally backed data. If so, copy it so we can then
// redirect it to the file so we don't lose the data
if (!m_is_file)
local_data = std::string(
static_cast<StreamString *>(m_opaque_up.get())->GetString());
}
m_opaque_up = std::make_unique<StreamFile>(file_sp);
m_is_file = true;
// If we had any data locally in our StreamString, then pass that along to
// the to new file we are redirecting to.
if (!local_data.empty())
m_opaque_up->Write(&local_data[0], local_data.size());
}
void SBStream::RedirectToFileDescriptor(int fd, bool transfer_fh_ownership) {
LLDB_INSTRUMENT_VA(this, fd, transfer_fh_ownership);
std::string local_data;
if (m_opaque_up) {
// See if we have any locally backed data. If so, copy it so we can then
// redirect it to the file so we don't lose the data
if (!m_is_file)
local_data = std::string(
static_cast<StreamString *>(m_opaque_up.get())->GetString());
}
m_opaque_up = std::make_unique<StreamFile>(fd, transfer_fh_ownership);
m_is_file = true;
// If we had any data locally in our StreamString, then pass that along to
// the to new file we are redirecting to.
if (!local_data.empty())
m_opaque_up->Write(&local_data[0], local_data.size());
}
lldb_private::Stream *SBStream::operator->() { return m_opaque_up.get(); }
lldb_private::Stream *SBStream::get() { return m_opaque_up.get(); }
lldb_private::Stream &SBStream::ref() {
if (m_opaque_up == nullptr)
m_opaque_up = std::make_unique<StreamString>();
return *m_opaque_up;
}
void SBStream::Clear() {
LLDB_INSTRUMENT_VA(this);
if (m_opaque_up) {
// See if we have any locally backed data. If so, copy it so we can then
// redirect it to the file so we don't lose the data
if (m_is_file)
m_opaque_up.reset();
else
static_cast<StreamString *>(m_opaque_up.get())->Clear();
}
}