feat(decoration_provider): log errors as error messages

src/nvim/decoration_provider.c

@@ -24,10 +24,17 @@ static kvec_t(DecorProvider) decor_providers = KV_INITIAL_VALUE;
 #define DECORATION_PROVIDER_INIT(ns_id) (DecorProvider) \
   { ns_id, false, LUA_NOREF, LUA_NOREF, \
     LUA_NOREF, LUA_NOREF, LUA_NOREF, \
-    LUA_NOREF, -1, false, false }
+    LUA_NOREF, -1, false, false, 0 }
 
-static bool decor_provider_invoke(NS ns_id, const char *name, LuaRef ref, Array args,
+static void decor_provider_error(DecorProvider *provider, const char *name, Error err)
-                                  bool default_true, char **perr)
+{
+  const char *ns_name = describe_ns(provider->ns_id);
+  ELOG("error in provider %s.%s: %s", ns_name, name, err.msg);
+  msg_schedule_semsg_multiline("Error in decoration provider %s.%s:\n%s", ns_name, name, err.msg);
+}
+
+static bool decor_provider_invoke(DecorProvider *provider, const char *name, LuaRef ref, Array args,
+                                  bool default_true)
 {
   Error err = ERROR_INIT;
 
@@ -39,17 +46,16 @@ static bool decor_provider_invoke(NS ns_id, const char *name, LuaRef ref, Array
 
   if (!ERROR_SET(&err)
       && api_object_to_bool(ret, "provider %s retval", default_true, &err)) {
+    provider->error_count = 0;
     return true;
   }
 
   if (ERROR_SET(&err)) {
-    const char *ns_name = describe_ns(ns_id);
+    decor_provider_error(provider, name, err);
-    ELOG("error in provider %s:%s: %s", ns_name, name, err.msg);
+    provider->error_count++;
-    bool verbose_errs = true;  // TODO(bfredl):
+
-    if (verbose_errs && perr && *perr == NULL) {
+    if (provider->error_count >= DP_MAX_ERROR) {
-      static char errbuf[IOSIZE];
+      provider->active = false;
-      snprintf(errbuf, sizeof errbuf, "%s: %s", ns_name, err.msg);
-      *perr = xstrdup(errbuf);
     }
   }
 
@@ -57,8 +63,7 @@ static bool decor_provider_invoke(NS ns_id, const char *name, LuaRef ref, Array
   return false;
 }
 
-void decor_providers_invoke_spell(win_T *wp, int start_row, int start_col, int end_row, int end_col,
+void decor_providers_invoke_spell(win_T *wp, int start_row, int start_col, int end_row, int end_col)
-                                  char **err)
 {
   for (size_t i = 0; i < kv_size(decor_providers); i++) {
     DecorProvider *p = &kv_A(decor_providers, i);
@@ -74,7 +79,7 @@ void decor_providers_invoke_spell(win_T *wp, int start_row, int start_col, int e
       ADD_C(args, INTEGER_OBJ(start_col));
       ADD_C(args, INTEGER_OBJ(end_row));
       ADD_C(args, INTEGER_OBJ(end_col));
-      decor_provider_invoke(p->ns_id, "spell", p->spell_nav, args, true, err);
+      decor_provider_invoke(p, "spell", p->spell_nav, args, true);
     }
   }
 }
@@ -83,7 +88,7 @@ void decor_providers_invoke_spell(win_T *wp, int start_row, int start_col, int e
 ///
 /// @param[out] providers Decoration providers
 /// @param[out] err       Provider err
-void decor_providers_start(DecorProviders *providers, char **err)
+void decor_providers_start(DecorProviders *providers)
 {
   kvi_init(*providers);
 
@@ -97,7 +102,7 @@ void decor_providers_start(DecorProviders *providers, char **err)
     if (p->redraw_start != LUA_NOREF) {
       MAXSIZE_TEMP_ARRAY(args, 2);
       ADD_C(args, INTEGER_OBJ((int)display_tick));
-      active = decor_provider_invoke(p->ns_id, "start", p->redraw_start, args, true, err);
+      active = decor_provider_invoke(p, "start", p->redraw_start, args, true);
     } else {
       active = true;
     }
@@ -116,7 +121,7 @@ void decor_providers_start(DecorProviders *providers, char **err)
 /// @param[out] line_providers Enabled line providers to invoke in win_line
 /// @param[out] err            Provider error
 void decor_providers_invoke_win(win_T *wp, DecorProviders *providers,
-                                DecorProviders *line_providers, char **err)
+                                DecorProviders *line_providers)
 {
   kvi_init(*line_providers);
 
@@ -133,7 +138,7 @@ void decor_providers_invoke_win(win_T *wp, DecorProviders *providers,
       // TODO(bfredl): we are not using this, but should be first drawn line?
       ADD_C(args, INTEGER_OBJ(wp->w_topline - 1));
       ADD_C(args, INTEGER_OBJ(knownmax));
-      if (decor_provider_invoke(p->ns_id, "win", p->redraw_win, args, true, err)) {
+      if (decor_provider_invoke(p, "win", p->redraw_win, args, true)) {
         kvi_push(*line_providers, p);
       }
     }
@@ -147,8 +152,7 @@ void decor_providers_invoke_win(win_T *wp, DecorProviders *providers,
 /// @param      row       Row to invoke line callback for
 /// @param[out] has_decor Set when at least one provider invokes a line callback
 /// @param[out] err       Provider error
-void decor_providers_invoke_line(win_T *wp, DecorProviders *providers, int row, bool *has_decor,
+void decor_providers_invoke_line(win_T *wp, DecorProviders *providers, int row, bool *has_decor)
-                                 char **err)
 {
   decor_state.running_on_lines = true;
   for (size_t k = 0; k < kv_size(*providers); k++) {
@@ -158,7 +162,7 @@ void decor_providers_invoke_line(win_T *wp, DecorProviders *providers, int row,
       ADD_C(args, WINDOW_OBJ(wp->handle));
       ADD_C(args, BUFFER_OBJ(wp->w_buffer->handle));
       ADD_C(args, INTEGER_OBJ(row));
-      if (decor_provider_invoke(p->ns_id, "line", p->redraw_line, args, true, err)) {
+      if (decor_provider_invoke(p, "line", p->redraw_line, args, true)) {
         *has_decor = true;
       } else {
         // return 'false' or error: skip rest of this window
@@ -176,7 +180,7 @@ void decor_providers_invoke_line(win_T *wp, DecorProviders *providers, int row,
 /// @param      buf       Buffer
 /// @param      providers Decoration providers
 /// @param[out] err       Provider error
-void decor_providers_invoke_buf(buf_T *buf, DecorProviders *providers, char **err)
+void decor_providers_invoke_buf(buf_T *buf, DecorProviders *providers)
 {
   for (size_t i = 0; i < kv_size(*providers); i++) {
     DecorProvider *p = kv_A(*providers, i);
@@ -184,7 +188,7 @@ void decor_providers_invoke_buf(buf_T *buf, DecorProviders *providers, char **er
       MAXSIZE_TEMP_ARRAY(args, 2);
       ADD_C(args, BUFFER_OBJ(buf->handle));
       ADD_C(args, INTEGER_OBJ((int64_t)display_tick));
-      decor_provider_invoke(p->ns_id, "buf", p->redraw_buf, args, true, err);
+      decor_provider_invoke(p, "buf", p->redraw_buf, args, true);
     }
   }
 }
@@ -194,14 +198,14 @@ void decor_providers_invoke_buf(buf_T *buf, DecorProviders *providers, char **er
 /// @param      providers   Decoration providers
 /// @param      displaytick Display tick
 /// @param[out] err         Provider error
-void decor_providers_invoke_end(DecorProviders *providers, char **err)
+void decor_providers_invoke_end(DecorProviders *providers)
 {
   for (size_t i = 0; i < kv_size(*providers); i++) {
     DecorProvider *p = kv_A(*providers, i);
     if (p && p->active && p->redraw_end != LUA_NOREF) {
       MAXSIZE_TEMP_ARRAY(args, 1);
       ADD_C(args, INTEGER_OBJ((int)display_tick));
-      decor_provider_invoke(p->ns_id, "end", p->redraw_end, args, true, err);
+      decor_provider_invoke(p, "end", p->redraw_end, args, true);
     }
   }
 }

src/nvim/decoration_provider.h

@@ -8,6 +8,8 @@
 #include "nvim/macros.h"
 #include "nvim/types.h"
 
+#define DP_MAX_ERROR 3
+
 typedef struct {
   NS ns_id;
   bool active;
@@ -20,6 +22,8 @@ typedef struct {
   LuaRef spell_nav;
   int hl_valid;
   bool hl_cached;
+
+  uint8_t error_count;
 } DecorProvider;
 
 typedef kvec_withinit_t(DecorProvider *, 4) DecorProviders;

src/nvim/drawline.c

@@ -261,17 +261,6 @@ done:
   return cells;
 }
 
-static inline void provider_err_virt_text(linenr_T lnum, char *err)
-{
-  Decoration err_decor = DECORATION_INIT;
-  int hl_err = syn_check_group(S_LEN("ErrorMsg"));
-  kv_push(err_decor.virt_text,
-          ((VirtTextChunk){ .text = err,
-                            .hl_id = hl_err }));
-  err_decor.virt_text_width = (int)mb_string2cells(err);
-  decor_add_ephemeral(lnum - 1, 0, lnum - 1, 0, &err_decor, 0, 0);
-}
-
 static void draw_virt_text(win_T *wp, buf_T *buf, int col_off, int *end_col, int max_col,
                            int win_row)
 {
@@ -1083,7 +1072,7 @@ static void win_line_continue(winlinevars_T *wlv)
 ///
 /// @return             the number of last row the line occupies.
 int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_only, spellvars_T *spv,
-             foldinfo_T foldinfo, DecorProviders *providers, char **provider_err)
+             foldinfo_T foldinfo, DecorProviders *providers)
 {
   winlinevars_T wlv;                  // variables passed between functions
 
@@ -1226,13 +1215,7 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
 
     has_decor = decor_redraw_line(wp, lnum - 1, &decor_state);
 
-    decor_providers_invoke_line(wp, providers, lnum - 1, &has_decor, provider_err);
+    decor_providers_invoke_line(wp, providers, lnum - 1, &has_decor);
-
-    if (*provider_err) {
-      provider_err_virt_text(lnum, *provider_err);
-      has_decor = true;
-      *provider_err = NULL;
-    }
 
     if (has_decor) {
       extra_check = true;

src/nvim/drawscreen.c

@@ -123,8 +123,6 @@ static bool redraw_popupmenu = false;
 static bool msg_grid_invalid = false;
 static bool resizing_autocmd = false;
 
-static char *provider_err = NULL;
-
 /// Check if the cursor line needs to be redrawn because of 'concealcursor'.
 ///
 /// When cursor is moved at the same time, both lines will be redrawn regardless.
@@ -542,7 +540,7 @@ int update_screen(void)
   ui_comp_set_screen_valid(true);
 
   DecorProviders providers;
-  decor_providers_start(&providers, &provider_err);
+  decor_providers_start(&providers);
 
   // "start" callback could have changed highlights for global elements
   if (win_check_ns_hl(NULL)) {
@@ -589,7 +587,7 @@ int update_screen(void)
       }
 
       if (buf->b_mod_tick_decor < display_tick) {
-        decor_providers_invoke_buf(buf, &providers, &provider_err);
+        decor_providers_invoke_buf(buf, &providers);
         buf->b_mod_tick_decor = display_tick;
       }
     }
@@ -669,7 +667,7 @@ int update_screen(void)
   }
   did_intro = true;
 
-  decor_providers_invoke_end(&providers, &provider_err);
+  decor_providers_invoke_end(&providers);
   kvi_destroy(providers);
 
   // either cmdline is cleared, not drawn or mode is last drawn
@@ -1446,7 +1444,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
   decor_redraw_reset(wp, &decor_state);
 
   DecorProviders line_providers;
-  decor_providers_invoke_win(wp, providers, &line_providers, &provider_err);
+  decor_providers_invoke_win(wp, providers, &line_providers);
 
   redraw_win_signcol(wp);
 
@@ -2237,7 +2235,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
         spellvars_T zero_spv = { 0 };
         row = win_line(wp, lnum, srow, wp->w_grid.rows, false,
                        foldinfo.fi_lines > 0 ? &zero_spv : &spv,
-                       foldinfo, &line_providers, &provider_err);
+                       foldinfo, &line_providers);
 
         if (foldinfo.fi_lines == 0) {
           wp->w_lines[idx].wl_folded = false;
@@ -2275,8 +2273,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
         // text doesn't need to be drawn, but the number column does.
         foldinfo_T info = wp->w_p_cul && lnum == wp->w_cursor.lnum ?
                           cursorline_fi : fold_info(wp, lnum);
-        (void)win_line(wp, lnum, srow, wp->w_grid.rows, true, &spv,
+        (void)win_line(wp, lnum, srow, wp->w_grid.rows, true, &spv, info, &line_providers);
-                       info, &line_providers, &provider_err);
       }
 
       // This line does not need to be drawn, advance to the next one.
@@ -2297,7 +2294,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
       lnum = wp->w_topline;
       wp->w_lines_valid = 0;
       wp->w_valid &= ~VALID_WCOL;
-      decor_providers_invoke_win(wp, providers, &line_providers, &provider_err);
+      decor_providers_invoke_win(wp, providers, &line_providers);
       continue;
     }
 
@@ -2375,7 +2372,7 @@ static void win_update(win_T *wp, DecorProviders *providers)
         spellvars_T zero_spv = { 0 };
         foldinfo_T zero_foldinfo = { 0 };
         row = win_line(wp, wp->w_botline, row, wp->w_grid.rows, false, &zero_spv,
-                       zero_foldinfo, &line_providers, &provider_err);
+                       zero_foldinfo, &line_providers);
       }
     } else if (dollar_vcol == -1) {
       wp->w_botline = lnum;

src/nvim/message.c

@@ -885,6 +885,24 @@ void msg_schedule_semsg(const char *const fmt, ...)
   loop_schedule_deferred(&main_loop, event_create(msg_semsg_event, 1, s));
 }
 
+static void msg_semsg_multiline_event(void **argv)
+{
+  char *s = argv[0];
+  (void)emsg_multiline(s, true);
+  xfree(s);
+}
+
+void msg_schedule_semsg_multiline(const char *const fmt, ...)
+{
+  va_list ap;
+  va_start(ap, fmt);
+  vim_vsnprintf((char *)IObuff, IOSIZE, fmt, ap);
+  va_end(ap);
+
+  char *s = xstrdup((char *)IObuff);
+  loop_schedule_deferred(&main_loop, event_create(msg_semsg_multiline_event, 1, s));
+}
+
 /// Like msg(), but truncate to a single line if p_shm contains 't', or when
 /// "force" is true.  This truncates in another way as for normal messages.
 /// Careful: The string may be changed by msg_may_trunc()!

src/nvim/spell.c

@@ -1214,11 +1214,10 @@ static void decor_spell_nav_start(win_T *wp)
   decor_redraw_reset(wp, &decor_state);
 }
 
-static TriState decor_spell_nav_col(win_T *wp, linenr_T lnum, linenr_T *decor_lnum, int col,
+static TriState decor_spell_nav_col(win_T *wp, linenr_T lnum, linenr_T *decor_lnum, int col)
-                                    char **decor_error)
 {
   if (*decor_lnum != lnum) {
-    decor_providers_invoke_spell(wp, lnum - 1, col, lnum - 1, -1, decor_error);
+    decor_providers_invoke_spell(wp, lnum - 1, col, lnum - 1, -1);
     decor_redraw_line(wp, lnum - 1, &decor_state);
     *decor_lnum = lnum;
   }
@@ -1277,7 +1276,6 @@ size_t spell_move_to(win_T *wp, int dir, bool allwords, bool curline, hlf_T *att
   linenr_T lnum = wp->w_cursor.lnum;
   clearpos(&found_pos);
 
-  char *decor_error = NULL;
   // Ephemeral extmarks are currently stored in the global decor_state.
   // When looking for spell errors, we need to:
   //  - temporarily reset decor_state
@@ -1362,7 +1360,7 @@ size_t spell_move_to(win_T *wp, int dir, bool allwords, bool curline, hlf_T *att
 
             bool no_plain_buffer = (wp->w_s->b_p_spo_flags & SPO_NPBUFFER) != 0;
             bool can_spell = !no_plain_buffer;
-            switch (decor_spell_nav_col(wp, lnum, &decor_lnum, col, &decor_error)) {
+            switch (decor_spell_nav_col(wp, lnum, &decor_lnum, col)) {
             case kTrue:
               can_spell = true; break;
             case kFalse:
@@ -1488,7 +1486,6 @@ size_t spell_move_to(win_T *wp, int dir, bool allwords, bool curline, hlf_T *att
 
 theend:
   decor_state_free(&decor_state);
-  xfree(decor_error);
   decor_state = saved_decor_start;
   xfree(buf);
   return ret;

test/functional/ui/decorations_spec.lua

@@ -37,6 +37,7 @@ describe('decorations providers', function()
       [15] = {special = Screen.colors.Blue, undercurl = true},
       [16] = {special = Screen.colors.Red, undercurl = true},
       [17] = {foreground = Screen.colors.Red},
+      [18] = {bold = true, foreground = Screen.colors.SeaGreen};
     }
   end)
 
@@ -611,6 +612,27 @@ describe('decorations providers', function()
       assert(eok == false)
     ]])
   end)
+
+  it('errors gracefully', function()
+    insert(mulholland)
+
+    setup_provider [[
+    function on_do(...)
+      error "Foo"
+    end
+    ]]
+
+    screen:expect{grid=[[
+      {2:Error in decoration provider ns1.start:} |
+      {2:Error executing lua: [string "<nvim>"]:4}|
+      {2:: Foo}                                   |
+      {2:stack traceback:}                        |
+      {2:        [C]: in function 'error'}        |
+      {2:        [string "<nvim>"]:4: in function}|
+      {2: <[string "<nvim>"]:3>}                  |
+      {18:Press ENTER or type command to continue}^ |
+    ]]}
+  end)
 end)
 
 local example_text = [[