llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-lldb Author: Charles Zablit (charles-zablit) <details> <summary>Changes</summary> On Windows `lldb --repl` can hang forever instead of exiting at EOF. `IOHandlerEditline::GetLine` checks `GetLastError() == ERROR_OPERATION_ABORTED` and does a `continue` before checking `feof`. However `fgets` is a CRT function and does not set the Win32 last error value, so the `GetLastError` read is not the expected error. When it happens to be `ERROR_OPERATION_ABORTED` (995) the loop never reaches the EOF check. This reorders the checks so EOF wins unconditionally, and adds `clearerr` before the ctrl-c retry (a real interrupt leaves the error flag set, which would fail the next `fgets`). ctrl-c handling is otherwise unchanged. rdar://183335061 --- Full diff: https://github.com/llvm/llvm-project/pull/212745.diff 1 Files Affected: - (modified) lldb/source/Core/IOHandler.cpp (+15-14) ``````````diff diff --git a/lldb/source/Core/IOHandler.cpp b/lldb/source/Core/IOHandler.cpp index 0bb8b58f24bff..a4477e4931b15 100644 --- a/lldb/source/Core/IOHandler.cpp +++ b/lldb/source/Core/IOHandler.cpp @@ -395,23 +395,24 @@ bool IOHandlerEditline::GetLine(std::string &line, bool &interrupted) { while (!got_line) { char *r = fgets(buffer, sizeof(buffer), in); #ifdef _WIN32 - // ReadFile on Windows is supposed to set ERROR_OPERATION_ABORTED - // according to the docs on MSDN. However, this has evidently been a - // known bug since Windows 8. Therefore, we can't detect if a signal - // interrupted in the fgets. So pressing ctrl-c causes the repl to end - // and the process to exit. A temporary workaround is just to attempt to - // fgets twice until this bug is fixed. - if (r == nullptr) - r = fgets(buffer, sizeof(buffer), in); - // this is the equivalent of EINTR for Windows - if (r == nullptr && GetLastError() == ERROR_OPERATION_ABORTED) - continue; -#endif if (r == nullptr) { + if (feof(in)) { + got_line = SplitLineEOF(m_line_buffer); + break; + } if (ferror(in) && errno == EINTR) continue; - if (feof(in)) - got_line = SplitLineEOF(m_line_buffer); + // ReadFile on Windows is supposed to set ERROR_OPERATION_ABORTED + // according to the docs on MSDN. However, this has evidently been a + // known bug since Windows 8. Therefore, we can't detect if a signal + // interrupted in the fgets. So pressing ctrl-c causes the repl to end + // and the process to exit. A temporary workaround is just to attempt + // to fgets twice until this bug is fixed. + if (GetLastError() == ERROR_OPERATION_ABORTED) { + clearerr(in); + continue; + } +#endif break; } m_line_buffer += buffer; `````````` </details> https://github.com/llvm/llvm-project/pull/212745 _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
