diff --git a/lldb/include/lldb/Host/File.h b/lldb/include/lldb/Host/File.h --- a/lldb/include/lldb/Host/File.h +++ b/lldb/include/lldb/Host/File.h @@ -411,6 +411,8 @@ size_t PrintfVarArg(const char *format, va_list args) override; llvm::Expected GetOptions() const override; + static FILE *ReleaseFILE(NativeFile &&file); + static char ID; virtual bool isA(const void *classID) const override { return classID == &ID || File::isA(classID); diff --git a/lldb/packages/Python/lldbsuite/test/python_api/file_handle/TestFileHandle.py b/lldb/packages/Python/lldbsuite/test/python_api/file_handle/TestFileHandle.py --- a/lldb/packages/Python/lldbsuite/test/python_api/file_handle/TestFileHandle.py +++ b/lldb/packages/Python/lldbsuite/test/python_api/file_handle/TestFileHandle.py @@ -851,10 +851,6 @@ yield sbf sbf.Write(str(i).encode('ascii') + b"\n") files = list(i(sbf)) - # delete them in reverse order, again because each is a borrow - # of the previous. - while files: - files.pop() with open(self.out_filename, 'r') as f: self.assertEqual(list(range(10)), list(map(int, f.read().strip().split()))) diff --git a/lldb/source/Host/common/File.cpp b/lldb/source/Host/common/File.cpp --- a/lldb/source/Host/common/File.cpp +++ b/lldb/source/Host/common/File.cpp @@ -304,6 +304,18 @@ return m_stream; } +FILE *NativeFile::ReleaseFILE(NativeFile &&file) { + FILE *stream = nullptr; + file.GetStream(); + if (file.m_own_stream) { + stream = file.m_stream; + file.m_own_stream = false; + file.m_stream = nullptr; + } + file.Close(); + return stream; +} + Status NativeFile::Close() { Status error; if (StreamIsValid()) { diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp --- a/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp +++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp @@ -1502,19 +1502,28 @@ file_obj = PyFile_FromFd(file.GetDescriptor(), nullptr, mode, -1, nullptr, "ignore", nullptr, 0); #else - // We pass ::flush instead of ::fclose here so we borrow the FILE* -- - // the lldb_private::File still owns it. NetBSD does not allow - // input files to be flushed, so we have to check for that case too. - int (*closer)(FILE *); - auto opts = file.GetOptions(); + // It's more or less safe to let a python program borrow a file descriptor. + // If they let it dangle and then use it, they'll probably get an exception. + // The worst that can happen is they'll wind up doing IO on the wrong + // descriptor. But it would be very unsafe to let a python program borrow + // a FILE*. They could actually crash the program just by keeping a + // reference to it around. Since in python 2 we must have a FILE* and + // not a descriptor, we dup the descriptor and fdopen a new FILE* to it + // so python can have something it can own safely. + auto opts = File::GetOptionsFromMode(mode); if (!opts) return opts.takeError(); - if (opts.get() & File::eOpenOptionWrite) - closer = ::fflush; - else - closer = [](FILE *) { return 0; }; - file_obj = PyFile_FromFile(file.GetStream(), py2_const_cast(""), - py2_const_cast(mode), closer); + int fd = file.GetDescriptor(); + if (!File::DescriptorIsValid(fd)) + return llvm::createStringError(llvm::inconvertibleErrorCode(), + "File has no file descriptor"); + NativeFile dupfile(fd, opts.get(), false); + FILE *stream = NativeFile::ReleaseFILE(std::move(dupfile)); + if (!stream) + return llvm::createStringError(llvm::inconvertibleErrorCode(), + "could not create FILE* stream"); + file_obj = PyFile_FromFile(stream, py2_const_cast(""), py2_const_cast(mode), + ::fclose); #endif if (!file_obj)