Package: emacs;
Reported by: Po Lu <luangruo <at> yahoo.com>
Date: Tue, 22 Nov 2022 01:52:02 UTC
Severity: normal
Found in version 29.0.50
Message #8 received at 59468 <at> debbugs.gnu.org (full text, mbox):
From: Yuan Fu <casouri <at> gmail.com> To: Po Lu <luangruo <at> yahoo.com> Cc: 59468 <at> debbugs.gnu.org Subject: Re: bug#59468: 29.0.50; c-ts-mode cannot fontify after macros are encountered Date: Tue, 22 Nov 2022 12:11:17 -0800
Po Lu <luangruo <at> yahoo.com> writes:
> Insert the following code in a buffer, and enable c-ts-mode.
>
> #define CheckExtension(name) \
> if (!name) \
> { \
> if (display) \
> eglTerminate (display); \
> fprintf (stderr, "Missing: egl%s\n", #name + 1); \
> return False; \
> }
>
> #define CheckExtensionGl(name) \
> if (!name) \
> { \
> /* If the context remains current, then nothing \
> will get released upon eglTerminate. */ \
> eglMakeCurrent (display, EGL_NO_SURFACE, \
> EGL_NO_SURFACE, EGL_NO_CONTEXT); \
> eglTerminate (display); \
> fprintf (stderr, "Missing: gl%s\n", #name + 1); \
> return False; \
> }
>
> #define LoadProc(name, ext, extname) \
> if (HaveEglExtension (extname)) \
> I##name \
> = (void *) eglGetProcAddress ("egl" #name ext)
>
> #define LoadProcGl(name, ext, extname) \
> if (HaveGlExtension (extname)) \
> I##name \
> = (void *) eglGetProcAddress ("gl" #name ext)
>
> #define CheckGlExtension(name) \
> if (!HaveGlExtension (name)) \
> { \
> fprintf (stderr, "Missing %s\n", name); \
> \
> eglMakeCurrent (display, EGL_NO_SURFACE, \
> EGL_NO_SURFACE, \
> EGL_NO_CONTEXT); \
> eglTerminate (display); \
> return False; \
> }
>
> There will be no fontification of types or string constants inside the
> macro bodies. CC Mode works fine.
>
> Now, insert the following code below the macro definition:
>
> static Visual *
> FindVisual (VisualID visual, int *depth)
> {
> XVisualInfo vinfo, *visuals;
> Visual *value;
> int nvisuals;
> const char *override;
> }
>
> visual, depth, visuals, value and override are not fontified as
> identifiers. Line feed characters below the macros are also fontfied as
> "errors".
>
> Within the following code:
>
> static BufferActivityRecord *
> FindBufferActivityRecord (PictureBuffer *buffer, PictureTarget *target)
> {
> BufferActivityRecord *record;
>
> /* Look through the global activity list for a record matching
> the given values. */
> record = all_activity.global_next;
> while (record != &all_activity)
> {
> if (record->buffer == buffer
> && record->target == target)
> return record;
>
> record = record->global_next;
> }
>
> return NULL;
> }
>
> "record" is fontified as an identifier, but not within the condition in
> the while loop.
>
> Within the following code:
>
> static void
> compare_single_row_8bpc4 (unsigned char *data, unsigned char *xdata,
> size_t size,
> struct image_difference_statistics *statistics)
> {
> unsigned char channel_a, channel_b;
> int diff;
> size_t i;
>
> for (i = 0; i < size; ++i)
> {
> channel_a = data[i];
> channel_b = xdata[i];
>
> diff = (int) channel_b - (int) channel_a;
> statistics->min_diff = MIN (statistics->min_diff,
> diff);
> statistics->max_diff = MAX (statistics->max_diff,
> diff);
> }
> }
>
> the "i" in "size_t i" is fontified as an identifier the first time, but
> not in future appearances in the function.
>
> Within src/xterm.c, every appearance of ATOM_REFS_INIT is fontified in
> the error face. Also, inside `xm_setup_dnd_targets',
>
> xm_targets_table_header header;
> xm_targets_table_rec **recs UNINIT;
> xm_byte_order byteorder;
>
> "recs" is fontified in the error face.
>
> recs = xmalloc (sizeof *recs);
> recs[0] = xmalloc (FLEXSIZEOF (struct xm_targets_table_rec,
> targets, ntargets * 4));
>
> recs[0]->n_targets = ntargets;
>
> "struct" is fontified in the error face. Within
> x_sync_note_frame_times:
>
> #ifdef FRAME_DEBUG
> uint_fast64_t last_frame_ms = output->last_frame_time / 1000;
> fprintf (stderr,
> "Drawing the last frame took: %"PRIuFAST64" ms (%"PRIuFAST64")\n",
> last_frame_ms, time);
> #endif
>
> "PRIuFAST64" is fontified in the error face. Within
> x_dnd_begin_drag_and_drop:
>
> if (x_dnd_movement_frame
> /* FIXME: how come this can end up with movement frames
> from other displays on GTK builds? */
> && (FRAME_X_DISPLAY (x_dnd_movement_frame)
> == FRAME_X_DISPLAY (f))
> /* If both those variables are false, then F is no
> longer protected from deletion by Lisp code. This
> can only happen during the final iteration of the DND
> event loop. */
> && (x_dnd_in_progress || x_dnd_waiting_for_finish))
> {
> XSETFRAME (frame_object, x_dnd_movement_frame);
>
> is fontified incorrectly: the "if" is not fontified at all, and the last
> three lines show up in the error faces.
>
> In addition:
>
> Lisp_Object
> x_dnd_begin_drag_and_drop (struct frame *f, Time time, Atom xaction,
> Lisp_Object return_frame, Atom *ask_action_list,
> const char **ask_action_names, size_t n_ask_actions,
> bool allow_current_frame, Atom *target_atoms,
> int ntargets, Lisp_Object selection_target_list,
> bool follow_tooltip)
>
> "Lisp_Object" and "x_dnd_begin_drag_and_drop" are not fontified at all.
>
> Here:
>
> /* Select for input extension events used by scroll bars. This will
> result in the corresponding core events not being generated for
> SCROLL_BAR. */
>
> MAYBE_UNUSED static void
> xi_select_scroll_bar_events (struct x_display_info *dpyinfo,
> Window scroll_bar)
>
> "void" is fontified in the error face.
>
> Here, in handle_one_xevent:
>
> #ifdef HAVE_XINPUT2
> if (event->type != GenericEvent)
> #endif
> any = x_any_window_to_frame (dpyinfo, event->xany.window);
> #ifdef HAVE_XINPUT2
> else
> any = NULL;
> #endif
>
> the "else" is fontified as a type.
>
> static int
> handle_one_xevent (struct x_display_info *dpyinfo,
> #ifndef HAVE_XINPUT2
> const XEvent *event,
> #else
> XEvent *event,
> #endif
> int *finish, struct input_event *hold_quit)
>
> the "const XEvent *" is fontified in the error face.
>
> Here:
>
> case GraphicsExpose: /* This occurs when an XCopyArea's
> source area was obscured or not
> available. */
> f = x_window_to_frame (dpyinfo, event->xgraphicsexpose.drawable);
> if (f)
> {
> expose_frame (f, event->xgraphicsexpose.x,
> event->xgraphicsexpose.y,
> event->xgraphicsexpose.width,
> event->xgraphicsexpose.height);
> #ifndef USE_TOOLKIT_SCROLL_BARS
> x_scroll_bar_handle_exposure (f, (XEvent *) event);
> #endif
> #ifdef USE_GTK
> x_clear_under_internal_border (f);
> #endif
> #ifdef HAVE_XDBE
> show_back_buffer (f);
> #endif
> }
> #ifdef USE_X_TOOLKIT
> else
> goto OTHER;
> #endif /* USE_X_TOOLKIT */
> break;
>
> "goto OTHER" is fontified in the error face, and "else" as a type.
>
> Here:
>
> #ifdef HAVE_XINPUT2
> if (event->xkey.time == pending_keystroke_time)
> {
> source = xi_device_from_id (dpyinfo,
> dpyinfo->pending_keystroke_source);
>
> if (source)
> inev.ie.device = source->name;
> }
> #endif
>
> "inev" is fontified in the error face.
>
> Here:
>
> #ifdef USE_GTK
> /* See comment in EnterNotify above */
> else if (dpyinfo->last_mouse_glyph_frame)
> x_note_mouse_movement (dpyinfo->last_mouse_glyph_frame,
> &event->xmotion, Qnil);
> #endif
>
> "else" and "dpyinfo" are fontified as types.
>
> #ifdef USE_MOTIF
> Widget widget;
>
> widget = XtWindowToWidget (dpyinfo->display,
> event->xbutton.window);
>
> if (widget && XmIsCascadeButton (widget)
> && XtIsSensitive (widget))
> {
> #endif
> if (!f->output_data.x->saved_menu_event)
> f->output_data.x->saved_menu_event = xmalloc (sizeof *event);
> *f->output_data.x->saved_menu_event = *event;
> inev.ie.kind = MENU_BAR_ACTIVATE_EVENT;
> XSETFRAME (inev.ie.frame_or_window, f);
> *finish = X_EVENT_DROP;
> #ifdef USE_MOTIF
> }
> #endif
>
> here, the last closing brace is fontified in the error face.
>
> Here:
>
> static void NO_INLINE
> x_error_quitter (Display *display, XErrorEvent *event)
> {
> char buf[256], buf1[400 + INT_STRLEN_BOUND (int)
> + INT_STRLEN_BOUND (unsigned long)];
>
> "NO_INLINE" and "unsigned long" are fontified in the error face.
>
> CC mode fontifies all of the examples above fine, and they are not even
> pre-standard C. Would someone please fix c-ts-mode to fontify them
> correctly as well?
>
Thanks for these reports! Buuuuut as we’ve seen, tree-sitter really
doesn’t handle macros that well. I’ll see what I can do when I find the
time, but there really isn’t any good solutions to this (right now, that
I can think of). I’m not even sure the author of tree-sitter-c would
accept changes that try to parse macros: he has made it clear that the
purpose of tree-sitter-c is to support post-processed C and leave macros
and preprocessor to error-recovery.
Yuan
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.