From ffa4ac956c9389aee7e46708492f61fdd69cd845 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 28 Aug 2013 12:25:05 +0000 Subject: [PATCH] gdb/ * event-top.c (gdb_setup_readline): Call stderr_fileopen instead of stdio_fileopen. * main.c (captured_main) [__MINGW32__]: Set stderr unbuffered. .Call stderr_fileopen instead of stdio_fileopen. * ui-file.c [__MINGW32__] (stderr_file_write): New function. [__MINGW32__] (stderr_file_fputs): New function. (stderr_fileopen): New function. * ui-file.h (stderr_fileopen): Declare. --- gdb/ChangeLog | 12 +++++++++++ gdb/event-top.c | 2 +- gdb/main.c | 9 ++++++++- gdb/ui-file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++ gdb/ui-file.h | 4 ++++ 5 files changed, 79 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 24168784ae3..e9d1eade87b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +2013-08-28 Yao Qi + Pedro Alves + + * event-top.c (gdb_setup_readline): Call stderr_fileopen + instead of stdio_fileopen. + * main.c (captured_main) [__MINGW32__]: Set stderr unbuffered. + .Call stderr_fileopen instead of stdio_fileopen. + * ui-file.c [__MINGW32__] (stderr_file_write): New function. + [__MINGW32__] (stderr_file_fputs): New function. + (stderr_fileopen): New function. + * ui-file.h (stderr_fileopen): Declare. + 2013-08-27 Doug Evans * dwarf2read.c (struct dwarf2_cu): Tweak comment. diff --git a/gdb/event-top.c b/gdb/event-top.c index f00ab7d84e1..f1d55b3c2da 100644 --- a/gdb/event-top.c +++ b/gdb/event-top.c @@ -955,7 +955,7 @@ gdb_setup_readline (void) time. */ if (!batch_silent) gdb_stdout = stdio_fileopen (stdout); - gdb_stderr = stdio_fileopen (stderr); + gdb_stderr = stderr_fileopen (); gdb_stdlog = gdb_stderr; /* for moment */ gdb_stdtarg = gdb_stderr; /* for moment */ gdb_stdtargerr = gdb_stderr; /* for moment */ diff --git a/gdb/main.c b/gdb/main.c index 1c240e4d398..11f4b03a3da 100644 --- a/gdb/main.c +++ b/gdb/main.c @@ -375,8 +375,15 @@ captured_main (void *data) saved_command_line[0] = '\0'; instream = stdin; +#ifdef __MINGW32__ + /* Ensure stderr is unbuffered. A Cygwin pty or pipe is implemented + as a Windows pipe, and Windows buffers on pipes. */ + setvbuf (stderr, NULL, _IONBF, BUFSIZ); +#endif + gdb_stdout = stdio_fileopen (stdout); - gdb_stderr = stdio_fileopen (stderr); + gdb_stderr = stderr_fileopen (); + gdb_stdlog = gdb_stderr; /* for moment */ gdb_stdtarg = gdb_stderr; /* for moment */ gdb_stdin = stdio_fileopen (stdin); diff --git a/gdb/ui-file.c b/gdb/ui-file.c index cf5a86d033c..b9d3e5309f5 100644 --- a/gdb/ui-file.c +++ b/gdb/ui-file.c @@ -654,6 +654,60 @@ stdio_file_fseek (struct ui_file *file, long offset, int whence) return fseek (stdio->file, offset, whence); } +#ifdef __MINGW32__ +/* This is the implementation of ui_file method to_write for stderr. + gdb_stdout is flushed before writing to gdb_stderr. */ + +static void +stderr_file_write (struct ui_file *file, const char *buf, long length_buf) +{ + gdb_flush (gdb_stdout); + stdio_file_write (file, buf, length_buf); +} + +/* This is the implementation of ui_file method to_fputs for stderr. + gdb_stdout is flushed before writing to gdb_stderr. */ + +static void +stderr_file_fputs (const char *linebuffer, struct ui_file *file) +{ + gdb_flush (gdb_stdout); + stdio_file_fputs (linebuffer, file); +} +#endif + +struct ui_file * +stderr_fileopen (void) +{ + struct ui_file *ui_file = stdio_fileopen (stderr); + +#ifdef __MINGW32__ + /* There is no real line-buffering on Windows, see + http://msdn.microsoft.com/en-us/library/86cebhfs%28v=vs.71%29.aspx + so the stdout is either fully-buffered or non-buffered. We can't + make stdout non-buffered, because of two concerns, + 1. non-buffering hurts performance, + 2. non-buffering may change GDB's behavior when it is interacting + with front-end, such as Emacs. + + We decided to leave stdout as fully buffered, but flush it first + when something is written to stderr. */ + + /* Method 'to_write_async_safe' is not overwritten, because there's + no way to flush a stream in an async-safe manner. Fortunately, + it doesn't really matter, because: + - that method is only used for printing internal debug output + from signal handlers. + - Windows hosts don't have a concept of async-safeness. Signal + handlers run in a separate thread, so they can call + the regular non-async-safe output routines freely. */ + set_ui_file_write (ui_file, stderr_file_write); + set_ui_file_fputs (ui_file, stderr_file_fputs); +#endif + + return ui_file; +} + /* Like fdopen(). Create a ui_file from a previously opened FILE. */ struct ui_file * diff --git a/gdb/ui-file.h b/gdb/ui-file.h index 9fef68c656d..ba0a9083e02 100644 --- a/gdb/ui-file.h +++ b/gdb/ui-file.h @@ -129,6 +129,10 @@ extern struct ui_file *mem_fileopen (void); /* Open/create a STDIO based UI_FILE using the already open FILE. */ extern struct ui_file *stdio_fileopen (FILE *file); +/* Create a ui_file from stderr. */ +extern struct ui_file *stderr_fileopen (void); + + /* Open NAME returning an STDIO based UI_FILE. */ extern struct ui_file *gdb_fopen (const char *name, const char *mode); -- 2.30.2