vim-patch:9.1.0997: too many strlen() calls in drawscreen.c (#31927)

Problem:  too many strlen() calls in drawscreen.c
Solution: refactor drawscreen.c and remove calls to strlen(),
          make get_keymap_str() (in screen.c) return string length
          instead of TRUE/FALSE (John Marriott).

https://github.com/vim/vim/commit/a21240b97debea2e087aee6ad1488b5f075d1259

Co-authored-by: John Marriott <basilisk@internode.on.net>

4 files changed, 85 insertions, 79 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 5dcf7d8f49..9e6877cbfa 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -3257,8 +3257,8 @@ void fileinfo(int fullname, int shorthelp, bool dont_truncate)
                      n);
     validate_virtcol(curwin);
     size_t len = strlen(buffer);
-    col_print(buffer + len, IOSIZE - len,
-              (int)curwin->w_cursor.col + 1, (int)curwin->w_virtcol + 1);
+    (void)col_print(buffer + len, IOSIZE - len,
+                    (int)curwin->w_cursor.col + 1, (int)curwin->w_virtcol + 1);
   }
 
   append_arg_number(curwin, buffer, IOSIZE);
@@ -3286,13 +3286,13 @@ void fileinfo(int fullname, int shorthelp, bool dont_truncate)
   xfree(buffer);
 }
 
-void col_print(char *buf, size_t buflen, int col, int vcol)
+int col_print(char *buf, size_t buflen, int col, int vcol)
 {
   if (col == vcol) {
-    vim_snprintf(buf, buflen, "%d", col);
-  } else {
-    vim_snprintf(buf, buflen, "%d-%d", col, vcol);
+    return vim_snprintf(buf, buflen, "%d", col);
   }
+
+  return vim_snprintf(buf, buflen, "%d-%d", col, vcol);
 }
 
 static char *lasttitle = NULL;
@@ -3416,15 +3416,16 @@ void free_titles(void)
 
 /// Get relative cursor position in window into "buf[buflen]", in the localized
 /// percentage form like %99, 99%; using "Top", "Bot" or "All" when appropriate.
-void get_rel_pos(win_T *wp, char *buf, int buflen)
+int get_rel_pos(win_T *wp, char *buf, int buflen)
 {
   // Need at least 3 chars for writing.
   if (buflen < 3) {
-    return;
+    return 0;
   }
 
   linenr_T above;          // number of lines above window
   linenr_T below;          // number of lines below window
+  int len;
 
   above = wp->w_topline - 1;
   above += win_get_fill(wp, wp->w_topline) - wp->w_topfill;
@@ -3435,25 +3436,24 @@ void get_rel_pos(win_T *wp, char *buf, int buflen)
   }
   below = wp->w_buffer->b_ml.ml_line_count - wp->w_botline + 1;
   if (below <= 0) {
-    xstrlcpy(buf, (above == 0 ? _("All") : _("Bot")), (size_t)buflen);
+    len = vim_snprintf(buf, (size_t)buflen, "%s", (above == 0) ? _("All") : _("Bot"));
   } else if (above <= 0) {
-    xstrlcpy(buf, _("Top"), (size_t)buflen);
+    len = vim_snprintf(buf, (size_t)buflen, "%s", _("Top"));
   } else {
     int perc = (above > 1000000
                 ? (above / ((above + below) / 100))
                 : (above * 100 / (above + below)));
-
-    char *p = buf;
-    size_t l = (size_t)buflen;
-    if (perc < 10) {
-      // prepend one space
-      buf[0] = ' ';
-      p++;
-      l--;
-    }
     // localized percentage value
-    vim_snprintf(p, l, _("%d%%"), perc);
+    len = vim_snprintf(buf, (size_t)buflen, _("%s%d%%"), (perc < 10) ? " " : "", perc);
   }
+  if (len < 0) {
+    buf[0] = NUL;
+    len = 0;
+  } else if (len > buflen - 1) {
+    len = buflen - 1;
+  }
+
+  return len;
 }
 
 /// Append (2 of 8) to "buf[buflen]", if editing more than one file.
diff --git a/src/nvim/digraph.c b/src/nvim/digraph.c
index aaa77f5fcf..326e929fb6 100644
--- a/src/nvim/digraph.c
+++ b/src/nvim/digraph.c
@@ -2183,22 +2183,22 @@ static void keymap_unload(void)
 /// @param fmt  format string containing one %s item
 /// @param buf  buffer for the result
 /// @param len  length of buffer
-bool get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
+int get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
 {
   char *p;
 
   if (wp->w_buffer->b_p_iminsert != B_IMODE_LMAP) {
-    return false;
+    return 0;
   }
 
   buf_T *old_curbuf = curbuf;
   win_T *old_curwin = curwin;
+  char to_evaluate[] = "b:keymap_name";
 
   curbuf = wp->w_buffer;
   curwin = wp;
-  STRCPY(buf, "b:keymap_name");       // must be writable
   emsg_skip++;
-  char *s = p = eval_to_string(buf, false, false);
+  char *s = p = eval_to_string(to_evaluate, false, false);
   emsg_skip--;
   curbuf = old_curbuf;
   curwin = old_curwin;
@@ -2209,9 +2209,12 @@ bool get_keymap_str(win_T *wp, char *fmt, char *buf, int len)
       p = "lang";
     }
   }
-  if (vim_snprintf(buf, (size_t)len, fmt, p) > len - 1) {
+  int plen = vim_snprintf(buf, (size_t)len, fmt, p);
+  xfree(s);
+  if (plen < 0 || plen > len - 1) {
     buf[0] = NUL;
+    plen = 0;
   }
-  xfree(s);
-  return buf[0] != NUL;
+
+  return plen;
 }
diff --git a/src/nvim/drawscreen.c b/src/nvim/drawscreen.c
index f8aeb02229..7f4de9eab8 100644
--- a/src/nvim/drawscreen.c
+++ b/src/nvim/drawscreen.c
@@ -1045,7 +1045,7 @@ int showmode(void)
         if (State & MODE_LANGMAP) {
           if (curwin->w_p_arab) {
             msg_puts_hl(_(" Arabic"), hl_id, false);
-          } else if (get_keymap_str(curwin, " (%s)", NameBuff, MAXPATHL)) {
+          } else if (get_keymap_str(curwin, " (%s)", NameBuff, MAXPATHL) > 0) {
             msg_puts_hl(NameBuff, hl_id, false);
           }
         }
@@ -1936,7 +1936,7 @@ static void win_update(win_T *wp)
                  pos.lnum += cursor_above ? 1 : -1) {
               colnr_T t;
 
-              pos.col = (colnr_T)strlen(ml_get_buf(wp->w_buffer, pos.lnum));
+              pos.col = ml_get_buf_len(wp->w_buffer, pos.lnum);
               getvvcol(wp, &pos, NULL, NULL, &t);
               toc = MAX(toc, t);
             }
diff --git a/src/nvim/statusline.c b/src/nvim/statusline.c
index d47340505a..fe6892cc27 100644
--- a/src/nvim/statusline.c
+++ b/src/nvim/statusline.c
@@ -96,53 +96,51 @@ void win_redr_status(win_T *wp)
 
     get_trans_bufname(wp->w_buffer);
     char *p = NameBuff;
-    int len = (int)strlen(p);
+    int plen = (int)strlen(p);
 
     if ((bt_help(wp->w_buffer)
          || wp->w_p_pvw
          || bufIsChanged(wp->w_buffer)
          || wp->w_buffer->b_p_ro)
-        && len < MAXPATHL - 1) {
-      *(p + len++) = ' ';
+        && plen < MAXPATHL - 1) {
+      *(p + plen++) = ' ';
     }
     if (bt_help(wp->w_buffer)) {
-      snprintf(p + len, MAXPATHL - (size_t)len, "%s", _("[Help]"));
-      len += (int)strlen(p + len);
+      plen += snprintf(p + plen, MAXPATHL - (size_t)plen, "%s", _("[Help]"));
     }
     if (wp->w_p_pvw) {
-      snprintf(p + len, MAXPATHL - (size_t)len, "%s", _("[Preview]"));
-      len += (int)strlen(p + len);
+      plen += snprintf(p + plen, MAXPATHL - (size_t)plen, "%s", _("[Preview]"));
     }
     if (bufIsChanged(wp->w_buffer)) {
-      snprintf(p + len, MAXPATHL - (size_t)len, "%s", "[+]");
-      len += (int)strlen(p + len);
+      plen += snprintf(p + plen, MAXPATHL - (size_t)plen, "%s", "[+]");
     }
     if (wp->w_buffer->b_p_ro) {
-      snprintf(p + len, MAXPATHL - (size_t)len, "%s", _("[RO]"));
-      // len += (int)strlen(p + len);  // dead assignment
+      plen += snprintf(p + plen, MAXPATHL - (size_t)plen, "%s", _("[RO]"));
     }
+    (void)plen;
 
-    int this_ru_col = MAX(ru_col - (Columns - stl_width), (stl_width + 1) / 2);
+    int n = (stl_width + 1) / 2;
+    int this_ru_col = ru_col - (Columns - stl_width);
+    this_ru_col = MAX(this_ru_col, n);
     if (this_ru_col <= 1) {
       p = "<";                // No room for file name!
-      len = 1;
+      plen = 1;
     } else {
       int i;
 
       // Count total number of display cells.
-      int clen = (int)mb_string2cells(p);
+      plen = (int)mb_string2cells(p);
 
       // Find first character that will fit.
       // Going from start to end is much faster for DBCS.
-      for (i = 0; p[i] != NUL && clen >= this_ru_col - 1;
+      for (i = 0; p[i] != NUL && plen >= this_ru_col - 1;
            i += utfc_ptr2len(p + i)) {
-        clen -= utf_ptr2cells(p + i);
+        plen -= utf_ptr2cells(p + i);
       }
-      len = clen;
       if (i > 0) {
         p = p + i - 1;
         *p = '<';
-        len++;
+        plen++;
       }
     }
 
@@ -152,16 +150,17 @@ void win_redr_status(win_T *wp)
     int width = grid_line_puts(off, p, -1, attr);
     grid_line_fill(off + width, off + this_ru_col, fillchar, attr);
 
-    if (get_keymap_str(wp, "<%s>", NameBuff, MAXPATHL)
-        && this_ru_col - len > (int)strlen(NameBuff) + 1) {
-      grid_line_puts(off + this_ru_col - (int)strlen(NameBuff) - 1, NameBuff, -1, attr);
+    int NameBufflen = get_keymap_str(wp, "<%s>", NameBuff, MAXPATHL);
+    if (NameBufflen > 0 && this_ru_col - plen > NameBufflen + 1) {
+      grid_line_puts(off + this_ru_col - NameBufflen - 1, NameBuff, -1, attr);
     }
 
     win_redr_ruler(wp);
 
     // Draw the 'showcmd' information if 'showcmdloc' == "statusline".
     if (p_sc && *p_sloc == 's') {
-      const int sc_width = MIN(10, this_ru_col - len - 2);
+      n = this_ru_col - plen - 2;  // perform the calculation here so we only do it once
+      const int sc_width = MIN(10, n);
 
       if (sc_width > 0) {
         grid_line_puts(off + this_ru_col - sc_width - 1, showcmd_buf, sc_width, attr);
@@ -548,36 +547,40 @@ void win_redr_ruler(win_T *wp)
 #define RULER_BUF_LEN 70
   char buffer[RULER_BUF_LEN];
 
-  // Some sprintfs return the length, some return a pointer.
-  // To avoid portability problems we use strlen() here.
-  vim_snprintf(buffer, RULER_BUF_LEN, "%" PRId64 ",",
-               (wp->w_buffer->b_ml.ml_flags &
-                ML_EMPTY) ? 0 : (int64_t)wp->w_cursor.lnum);
-  size_t len = strlen(buffer);
-  col_print(buffer + len, RULER_BUF_LEN - len,
-            empty_line ? 0 : (int)wp->w_cursor.col + 1,
-            (int)virtcol + 1);
+  int bufferlen = vim_snprintf(buffer, RULER_BUF_LEN, "%" PRId64 ",",
+                               (wp->w_buffer->b_ml.ml_flags & ML_EMPTY)
+                               ? 0
+                               : (int64_t)wp->w_cursor.lnum);
+  bufferlen += col_print(buffer + bufferlen, RULER_BUF_LEN - (size_t)bufferlen,
+                         empty_line ? 0 : (int)wp->w_cursor.col + 1,
+                         (int)virtcol + 1);
 
   // Add a "50%" if there is room for it.
   // On the last line, don't print in the last column (scrolls the
   // screen up on some terminals).
-  int i = (int)strlen(buffer);
-  get_rel_pos(wp, buffer + i + 1, RULER_BUF_LEN - i - 1);
-  int o = i + vim_strsize(buffer + i + 1);
+  char rel_pos[RULER_BUF_LEN];
+  int rel_poslen = get_rel_pos(wp, rel_pos, RULER_BUF_LEN);
+  int n1 = bufferlen + vim_strsize(rel_pos);
   if (wp->w_status_height == 0 && !is_stl_global) {  // can't use last char of screen
-    o++;
+    n1++;
   }
+
+  int this_ru_col = ru_col - (Columns - width);
   // Never use more than half the window/screen width, leave the other half
   // for the filename.
-  int this_ru_col = MAX(ru_col - (Columns - width), (width + 1) / 2);
-  if (this_ru_col + o < width) {
-    // Need at least 3 chars left for get_rel_pos() + NUL.
-    while (this_ru_col + o < width && RULER_BUF_LEN > i + 4) {
-      i += (int)schar_get(buffer + i, fillchar);
-      o++;
-    }
-    get_rel_pos(wp, buffer + i, RULER_BUF_LEN - i);
+  int n2 = (width + 1) / 2;
+  this_ru_col = MAX(this_ru_col, n2);
+  if (this_ru_col + n1 < width) {
+    // need at least space for rel_pos + NUL
+    while (this_ru_col + n1 < width
+           && RULER_BUF_LEN > bufferlen + rel_poslen + 1) {  // +1 for NUL
+      bufferlen += (int)schar_get(buffer + bufferlen, fillchar);
+      n1++;
+    }
+    bufferlen += vim_snprintf(buffer + bufferlen, RULER_BUF_LEN - (size_t)bufferlen,
+                              "%s", rel_pos);
   }
+  (void)bufferlen;
 
   if (ui_has(kUIMessages) && !part_of_status) {
     MAXSIZE_TEMP_ARRAY(content, 1);
@@ -595,11 +598,11 @@ void win_redr_ruler(win_T *wp)
       did_show_ext_ruler = false;
     }
     // Truncate at window boundary.
-    o = 0;
-    for (i = 0; buffer[i] != NUL; i += utfc_ptr2len(buffer + i)) {
-      o += utf_ptr2cells(buffer + i);
-      if (this_ru_col + o > width) {
-        buffer[i] = NUL;
+    for (n1 = 0, n2 = 0; buffer[n1] != NUL; n1 += utfc_ptr2len(buffer + n1)) {
+      n2 += utf_ptr2cells(buffer + n1);
+      if (this_ru_col + n2 > width) {
+        bufferlen = n1;
+        buffer[bufferlen] = NUL;
         break;
       }
     }
@@ -1536,7 +1539,7 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, OptIndex op
       // Store the position percentage in our temporary buffer.
       // Note: We cannot store the value in `num` because
       //       `get_rel_pos` can return a named position. Ex: "Top"
-      get_rel_pos(wp, buf_tmp, TMPLEN);
+      (void)get_rel_pos(wp, buf_tmp, TMPLEN);
       str = buf_tmp;
       break;
 
@@ -1564,7 +1567,7 @@ int build_stl_str_hl(win_T *wp, char *out, size_t outlen, char *fmt, OptIndex op
 
     case STL_KEYMAP:
       fillable = false;
-      if (get_keymap_str(wp, "<%s>", buf_tmp, TMPLEN)) {
+      if (get_keymap_str(wp, "<%s>", buf_tmp, TMPLEN) > 0) {
         str = buf_tmp;
       }
       break;