Don't freeze if an exiting process can't be read from. (Bug#19860).
This fixes a bug I introduced in
2014-07-08T07:24:07Z@eggert@cs.ucla.edu
"* process.c: Add sanity checks for file descriptors."
Dmitry Gutov did most of the legwork in finding the problem.
* src/process.c (wait_reading_process_output):
Treat non-running processes that can't be read from
the same as other non-running processes.
* src/w32.h (register_aux_fd): New function declaration.
* src/w32.c (register_aux_fd): New function.
* src/process.h (struct Lisp_Process): New member stderrproc.
* src/process.c (PIPECONN_P): New macro.
(PIPECONN1_P): New macro.
(Fdelete_process, Fprocess_status, Fset_process_buffer)
(Fset_process_filter, Fset_process_sentinel, Fstop_process)
(Fcontinue_process): Handle pipe process specially.
(create_process): Respect p->stderrproc.
(Fmake_pipe_process): New function.
(Fmake_process): Add new keyword argument :stderr.
(wait_reading_process_output): Specially handle a pipe process when
it gets an EOF.
(syms_of_process): Register Qpipe and Smake_pipe_process.
* doc/lispref/processes.texi (Asynchronous Processes): Document
`make-pipe-process' and `:stderr' keyword of `make-process'.
* lisp/subr.el (start-process): Suggest to use `make-process' handle
standard error separately.
* test/automated/process-tests.el (process-test-stderr-buffer)
(process-test-stderr-filter): New tests.
* etc/NEWS: Mention new process type `pipe' and its usage with the
`:stderr' keyword of `make-process'.
From a suggestion by Eli Zaretskii in:
http://lists.gnu.org/archive/html/emacs-devel/2015-03/msg00824.html
* process.c (NON_BLOCKING_CONNECT): Simplify by assuming that
BROKEN_NON_BLOCKING_CONNECT is not defined.
(SELECT_CAN_DO_WRITE_MASK): Remove, and assume it's now true.
* etc/NEWS: Mention change to `process-running-child-p`.
* src/process.c (Fprocess_running_child_p): Return number identifier of
the foreground process group if we know it.
Fixes Bug#15880.
This patch also makes Q constants (e.g., Qnil) constant addresses
from the C point of view.
* make-docfile.c: Revamp to generate table of symbols, too.
Include <stdbool.h>.
(xstrdup): New function.
(main): Don't process the same file twice.
(SYMBOL): New constant in enum global_type.
(struct symbol): Turn 'value' member into a union, either v.value
for int or v.svalue for string. All uses changed.
(add_global): New arg svalue, which overrides value, so that globals
can have a string value.
(close_emacs_global): New arg num_symbols; all uses changed.
Output lispsym decl.
(write_globals): Output symbol globals too. Output more
ATTRIBUTE_CONST, now that Qnil etc. are C constants.
Output defsym_name table.
(scan_c_file): Move most of guts into ...
(scan_c_stream): ... new function. Scan for DEFSYMs and
record symbols found. Don't read past EOF if file doesn't
end in newline.
* alloc.c, bidi.c, buffer.c, bytecode.c, callint.c, casefiddle:
* casetab.c, category.c, ccl.c, charset.c, chartab.c, cmds.c, coding.c:
* composite.c, data.c, dbusbind.c, decompress.c, dired.c, dispnew.c:
* doc.c, editfns.c, emacs.c, eval.c, fileio.c, fns.c, font.c, fontset.c:
* frame.c, fringe.c, ftfont.c, ftxfont.c, gfilenotify.c, gnutls.c:
* image.c, inotify.c, insdel.c, keyboard.c, keymap.c, lread.c:
* macfont.m, macros.c, minibuf.c, nsfns.m, nsfont.m, nsimage.m:
* nsmenu.m, nsselect.m, nsterm.m, print.c, process.c, profiler.c:
* search.c, sound.c, syntax.c, term.c, terminal.c, textprop.c, undo.c:
* window.c, xdisp.c, xfaces.c, xfns.c, xftfont.c, xmenu.c, xml.c:
* xselect.c, xsettings.c, xterm.c:
Remove Q vars that represent symbols (e.g., Qnil, Qt, Qemacs).
These names are now defined automatically by make-docfile.
* alloc.c (init_symbol): New function.
(Fmake_symbol): Use it.
(c_symbol_p): New function.
(valid_lisp_object_p, purecopy): Use it.
* alloc.c (marked_pinned_symbols):
Use make_lisp_symbol instead of make_lisp_ptr.
(garbage_collect_1): Mark lispsym symbols.
(CHECK_ALLOCATED_AND_LIVE_SYMBOL): New macro.
(mark_object): Use it.
(sweep_symbols): Sweep lispsym symbols.
(symbol_uses_obj): New function.
(which_symbols): Use it. Work for lispsym symbols, too.
(init_alloc_once): Initialize Vpurify_flag here; no need to wait,
since Qt's address is already known now.
(syms_of_alloc): Add lispsym count to symbols_consed.
* buffer.c (init_buffer_once): Compare to Qnil, not to make_number (0),
when testing whether storage is all bits zero.
* dispextern (struct image_type):
* font.c (font_property_table):
* frame.c (struct frame_parm_table, frame_parms):
* keyboard.c (scroll_bar_parts, struct event_head):
* xdisp.c (struct props):
Use XSYMBOL_INIT (Qfoo) and struct Lisp_Symbol * rather than &Qfoo and
Lisp_Object *, since Qfoo is no longer an object whose address can be
taken. All uses changed.
* eval.c (run_hook): New function. Most uses of Frun_hooks changed to
use it, so that they no longer need to take the address of a Lisp sym.
(syms_of_eval): Don't use DEFSYM on Vrun_hooks, as it's a variable.
* frame.c (syms_of_frame): Add defsyms for the frame_parms table.
* keyboard.c (syms_of_keyboard): Don't DEFSYM Qmenu_bar here.
DEFSYM Qdeactivate_mark before the corresponding var.
* keymap.c (syms_of_keymap): Use DEFSYM for Qmenu_bar and Qmode_line
instead of interning their symbols; this avoids duplicates.
(LISP_INITIALLY, TAG_PTR)
(DEFINE_LISP_SYMBOL_BEGIN, DEFINE_LISP_SYMBOL_END, XSYMBOL_INIT):
New macros.
(LISP_INITIALLY_ZERO): Use it.
(enum symbol_interned, enum symbol_redirect, struct Lisp_Symbol)
(EXFUN, DEFUN_ARGS_MANY, DEFUN_ARGS_UNEVALLED, DEFUN_ARGS_*):
Move decls up, to avoid forward uses. Include globals.h earlier, too.
(make_lisp_symbol): New function.
(XSETSYMBOL): Use it.
(DEFSYM): Now just a placeholder for make-docfile.
* lread.c (DEFINE_SYMBOLS): Define, for globals.h.
(intern_sym): New function, with body taken from old intern_driver.
(intern_driver): Use it. Last arg is now Lisp integer, not ptrdiff_t.
All uses changed.
(define_symbol): New function.
(init_obarray): Define the C symbols taken from lispsym.
Use plain DEFSYM for Qt and Qnil.
* syntax.c (init_syntax_once): No need to worry about
Qchar_table_extra_slots.
* src/dispnew.c (update_single_window): Remove arg `force_p' since it's
always true.
* src/xfaces.c (clear_face_cache): Use bool for the argument type.
* doc/lispref/internals.texi (Stack-allocated Objects):
Adjust to match the revised, less error-prone macros.
* src/frame.h (AUTO_FRAME_ARG): Rename from FRAME_PARAMETER.
* src/lisp.h (AUTO_CONS): Rename from scoped_cons.
(AUTO_LIST1): Rename from scoped_list1.
(AUTO_LIST2): Rename from scoped_list2.
(AUTO_LIST3): Rename from scoped_list3.
(AUTO_LIST4): Rename from scoped_list4.
(AUTO_STRING): Rename from SCOPED_STRING.
* src/frame.h (AUTO_FRAME_ARG):
* src/lisp.h (AUTO_CONS, AUTO_LIST1, AUTO_LIST2, AUTO_LIST3)
(AUTO_LIST4, AUTO_STRING):
Prepend a new argument 'name'.
Declare a variable instead of yielding a value.
All uses changed.
* src/lisp.h (STACK_CONS, AUTO_CONS_EXPR): New internal macros.
The build_local_string macro was used in two ways: (1) string
literals for which scoped allocation suffices, and (2) file name
components, where it's not safe in general to assume bounded-size
ASCII data. Simplify by defining a new macro SCOPED_STRING that
allocates a block-scope string, and by using SCOPED_STRING for (1)
and build_string for (2). Furthermore, actually use stack
allocation only for objects known to have sufficient alignment.
This simpler implementation means Emacs can make
USE_STACK_LISP_OBJECTS the default unless GC_MARK_STACK !=
GC_MAKE_GCPROS_NOOPS.
* lisp.h (GCALIGNED): Align even if !USE_STACK_LISP_OBJECTS,
for fewer differences among implementations.
(struct Lisp_String): Now GCALIGNED.
(USE_STACK_LISP_OBJECTS): Default to true, since the
implementation no longer insists on a nonempty GCALIGNED.
But make it false if GC_MARK_STACK != GC_MAKE_GCPROS_NOOPS.
(SCOPED_CONS_INITIALIZER): Remove, since it's no longer needed
separately. Move definiens to scoped_cons. The old definition
was incorrect when GCALIGNED was defined to be empty.
(union Aligned_String): New type.
(USE_STACK_CONS, USE_STACK_STRING): New constants, so that the
implementation ports to compilers that don't align strictly enough.
Don't worry about the union sizes; it's not worth bothering about.
(scoped_cons, scoped_list1, scoped_list3, scoped_list4):
Rewrite using USE_STACK_CONS.
(scoped_cons): Assume the use of union Aligned_Cons.
(lisp_string_size, make_local_string, build_local_string): Remove.
Unless otherwise specified, all callers of build_local_string
changed to use SCOPED_STRING.
(SCOPED_STRING): New macro.
* data.c (wrong_choice):
* menu.c (single_menu_item):
* process.c (Fformat_network_address):
Hoist use of SCOPED_STRING out of a scope, so that its returned
object lives long enough.
* fileio.c (Fexpand_file_name): Use build_string, not SCOPED_STRING,
as the string might be long or might not be ASCII.
* configure.ac (HAVE_STATEMENT_EXPRESSIONS): Remove.
For USE_STACK_LISP_OBJECTS, we always assume __GNUC__.
* lisp.h (union Aligned_Cons) [!GCALIGNED]: Define as such.
(SCOPED_CONS_INITIALIZER): New macro.
(scoped_cons) [USE_STACK_LISP_OBJECTS]: Use it.
(USE_LOCAL_ALLOCA): Remove.
(local_cons, local_list1, local_list2, local_list3, local_list4):
Remove. Stack overflow checking makes them too slow.
(make_local_vector): Likewise. Also we just don't have enough
users for it.
(enum LISP_STRING_OVERHEAD): Remove.
(local_string_init, local_vector_init): Remove prototypes.
(make_local_string, build_local_string): Redesign to target short
compile-time string constants, fall back to regular string allocation
where appropriate.
(lisp_string_size): New function.
(verify_ascii) [ENABLE_CHECKING]: Add prototype.
* alloc.c (local_string_init, local_vector_init): Remove.
(verify_ascii) [ENABLE_CHECKING]: New function.
* buffer.c, charset.c, chartab.c, data.c, editfns.c, emacs.c, fileio.c:
* fns.c, font.c, fontset.c, frame.c, keyboard.c, keymap.c, lread.c:
* menu.c, minibuf.c, process.c, textprop.c, xdisp.c, xfns.c, xfont.c:
* xselect.c, xterm.c: All related users changed.
This follows up on the recent thread in emacs-devel on alloca; see:
http://lists.gnu.org/archive/html/emacs-devel/2014-09/msg00042.html
This patch also cleans up alloca-related glitches noted while
examining the code looking for unbounded alloca.
* alloc.c (listn):
* callproc.c (init_callproc):
Rewrite to avoid need for alloca.
* buffer.c (mouse_face_overlay_overlaps)
(report_overlay_modification):
* buffer.h (GET_OVERLAYS_AT):
* coding.c (make_subsidiaries):
* doc.c (Fsnarf_documentation):
* editfns.c (Fuser_full_name):
* fileio.c (Ffile_name_directory, Fexpand_file_name)
(search_embedded_absfilename, Fsubstitute_in_file_name):
* fns.c (Fmake_hash_table):
* font.c (font_vconcat_entity_vectors, font_update_drivers):
* fontset.c (fontset_pattern_regexp, Ffontset_info):
* frame.c (Fmake_terminal_frame, x_set_frame_parameters)
(xrdb_get_resource, x_get_resource_string):
* ftfont.c (ftfont_get_charset, ftfont_check_otf, ftfont_drive_otf):
* ftxfont.c (ftxfont_draw):
* image.c (xbm_load, xpm_load, jpeg_load_body):
* keyboard.c (echo_add_key, menu_bar_items, tool_bar_items):
* keymap.c (Fdescribe_buffer_bindings, describe_map):
* lread.c (openp):
* menu.c (digest_single_submenu, find_and_call_menu_selection)
(find_and_return_menu_selection):
* print.c (PRINTFINISH):
* process.c (Fformat_network_address):
* scroll.c (do_scrolling, do_direct_scrolling, scrolling_1):
* search.c (search_buffer, Fmatch_data, Fregexp_quote):
* sound.c (wav_play, au_play):
* syntax.c (skip_chars):
* term.c (tty_menu_activate, tty_menu_show):
* textprop.c (get_char_property_and_overlay):
* window.c (Fset_window_configuration):
* xdisp.c (safe__call, next_overlay_change, vmessage)
(compute_overhangs_and_x, draw_glyphs, note_mouse_highlight):
* xfaces.c (face_at_buffer_position):
* xmenu.c (x_menu_show):
Use SAFE_ALLOCA etc. instead of plain alloca, since the
allocation size isn't bounded.
* callint.c (Fcall_interactively): Redo memory_full check
so that it can be done at compile-time on some platforms.
* coding.c (MAX_LOOKUP_MAX): New constant.
(get_translation_table): Use it.
* callproc.c (call_process): Use SAFE_NALLOCA instead of
SAFE_ALLOCA, to catch integer overflows on size calculation.
(exec_failed) [!DOS_NT]: New function.
(child_setup) [!DOS_NT]: Use it.
* editfns.c (Ftranspose_regions):
Hoist USE_SAFE_ALLOC + SAFE_FREE out of 'if'.
* editfns.c (check_translation):
Allocate larger buffers on the heap.
* eval.c (internal_lisp_condition_case):
Check for MAX_ALLOCA overflow.
* fns.c (sort_vector): Use SAFE_ALLOCA_LISP rather than Fmake_vector.
(Fbase64_encode_region, Fbase64_decode_region):
Avoid unnecessary calls to SAFE_FREE before 'error'.
* buffer.c (mouse_face_overlay_overlaps):
* editfns.c (Fget_pos_property, check_translation):
* eval.c (Ffuncall):
* font.c (font_unparse_xlfd, font_find_for_lface):
* ftfont.c (ftfont_drive_otf):
* keyboard.c (echo_add_key, read_decoded_event_from_main_queue)
(menu_bar_items, tool_bar_items):
* sound.c (Fplay_sound_internal):
* xdisp.c (load_overlay_strings, dump_glyph_row):
Use an ordinary auto buffer rather than alloca, since the
allocation size is fixed and small.
* ftfont.c: Include <c-strcase.h>.
(matching_prefix): New function.
(get_adstyle_property): Use it, to avoid need for alloca.
* keyboard.c (echo_add_key):
* keymap.c (describe_map): Use ptrdiff_t, not int.
* keyboard.c (echo_add_key): Prefer sizeof to strlen.
* keymap.c (Fdescribe_buffer_bindings): Use SBYTES, not SCHARS,
when counting bytes.
* lisp.h (xlispstrdupa): Remove, replacing with ...
(SAFE_ALLOCA_STRING): ... new macro with different API.
This fixes a portability problem, namely, alloca result
passed to another function. All uses changed.
(SAFE_ALLOCA, SAFE_ALLOCA_LISP): Check for MAX_ALLOCA,
not MAX_ALLOCA - 1.
* regex.c (REGEX_USE_SAFE_ALLOCA, REGEX_SAFE_FREE)
(REGEX_ALLOCATE): New macros.
(REGEX_REALLOCATE, REGEX_ALLOCATE_STACK, REGEX_REALLOCATE_STACK)
(REGEX_FREE_STACK, FREE_VARIABLES, re_match_2_internal):
Use them.
* xdisp.c (message3): Use SAFE_ALLOCA_STRING rather than doing it
by hand.
(decode_mode_spec_coding): Store directly into buf rather than
into an alloca temporary and copying the temporary to the buf.
Fixes: debbugs:18410
* configure.ac (toplevel): Check whether GNU/Linux-specific
timerfd functions and macros are available.
* m4/clock_time.m4 (gl_CLOCK_TIME): Check for clock_getres as well.
* src/atimer.c (toplevel) [HAVE_TIMERFD]: Include sys/timerfd.h.
(toplevel): Rename alarm_timer_ok to special_timer_available.
[HAVE_TIMERFD]: Declare timerfd.
[HAVE_CLOCK_GETRES]: Declare resolution.
(start_atimer) [HAVE_CLOCK_GETRES]: Round up timestamp to
system timer resolution.
(set_alarm) [HAVE_TIMERFD]: Use timerfd_settime.
(timerfd_callback) [HAVE_TIMERFD]: New function.
(atimer_result, debug_timer_callback, Fdebug_timer_check)
[ENABLE_CHECKING]: New function for the sake of automated tests.
(init_atimer) [HAVE_TIMERFD]: Setup timerfd.
[HAVE_CLOCK_GETRES]: Likewise for system timer resolution.
[ENABLE_CHECKING]: Defsubr test function.
* src/atimer.h (timerfd_callback) [HAVE_TIMERFD]: Add prototype.
* src/lisp.h (add_timer_wait_descriptor) [HAVE_TIMERFD]: Likewise.
* src/process.c (add_timer_wait_descriptor) [HAVE_TIMERFD]: New function.
* test/automated/timer-tests.el (timer-tests-debug-timer-check): New test.
There is certainly nothing wrong with writing code like 'lo <= i
&& i <= hi', even if LO happens to a constant. There isn't even
anything wrong in general with writing 'a <= b' if A happens to
be a constant. At any rate stylistic changes shouldn't
be done like this without discussion.
(wait_reading_process_output, Fprocess_filter_multibyte_p):
Check that infd is nonnegative before using it as an fd.
(read_and_dispose_of_process_output, Fprocess_send_eof):
Likewise, for outfd.
(wait_reading_process_output): Omit unnecessary check of infd.
Fixes: debbugs:17844
* image.c (Fimagemagick_types):
* lisp.h (lisp_h_CHECK_TYPE, CHECK_TYPE, CHECK_ARRAY):
* process.c (Fmake_network_process):
Rename C local identifier 'Qfoo to avoid giving the false
impression that it stands for the symbol 'foo'.
* lisp.h, process.c (wait_reading_process_input):
Return int, not bool. All uses changed.
* process.c (SELECT_CANT_DO_WRITE_MASK):
Remove macro, replacing with ...
(SELECT_CAN_DO_WRITE_MASK): ... new constant, with inverted sense.
All uses changed.
(status_notify): New arg WAIT_PROC. Return int, not void.
All uses changed.
Fixes: debbugs:17647
* doc/lispref/processes.texi (Accepting Output):
* src/process.c (Faccept_process_output)
(wait_reading_process_output): Mention that if PROCESS is non-nil,
the return value is about PROCESS, not about other processes.
* nt/inc/ms-w32.h (POLL_FOR_INPUT): Likewise.
* src/keyboard.c, src/process.c: Do not define POLL_FOR_INPUT here
because it will be defined in generated config.h if needed.
* process.c (process_send_signal): Fix race condition where a
subprocess was reaped by a signal handler between the check for
liveness and calling 'kill', which meant that Emacs could in
theory kill an innocent bystander process. Do the fix by blocking
SIGCHLD in a critical section that checks liveness before killing.
Fixes: debbugs:17561
* lib-src/emacsclient.c (WCONTINUED): Move to ../src/syswait.h.
* src/process.c (handle_child_signal): Remove WCONTINUED ifdef,
because WCONTINUED is always defined now.
* src/syswait.h (WCONTINUED): Move here from ../lib-src/emacsclient.c.
Fixes: debbugs:15110 debbugs:17339
