vim-patch:8.1.2001: some source files are too big (#21231)

Problem:    Some source files are too big.
Solution:   Move buffer and window related functions to evalbuffer.c and
            evalwindow.c. (Yegappan Lakshmanan, closes vim/vim#4898)

https://github.com/vim/vim/commit/261f346f8154c0ec7094a4a211c653c74e9f7c2e

17 files changed, 1736 insertions, 1637 deletions

diff --git a/src/nvim/api/options.c b/src/nvim/api/options.c
index d705636479..bfcb99754f 100644
--- a/src/nvim/api/options.c
+++ b/src/nvim/api/options.c
@@ -11,6 +11,7 @@
 #include "nvim/api/private/helpers.h"
 #include "nvim/autocmd.h"
 #include "nvim/buffer_defs.h"
+#include "nvim/eval/window.h"
 #include "nvim/globals.h"
 #include "nvim/memory.h"
 #include "nvim/option.h"
diff --git a/src/nvim/api/window.c b/src/nvim/api/window.c
index 8d17570077..60fbc55363 100644
--- a/src/nvim/api/window.c
+++ b/src/nvim/api/window.c
@@ -13,6 +13,7 @@
 #include "nvim/buffer_defs.h"
 #include "nvim/cursor.h"
 #include "nvim/drawscreen.h"
+#include "nvim/eval/window.h"
 #include "nvim/ex_docmd.h"
 #include "nvim/gettext.h"
 #include "nvim/globals.h"
diff --git a/src/nvim/arglist.c b/src/nvim/arglist.c
index 8621e48754..0d52cf647f 100644
--- a/src/nvim/arglist.c
+++ b/src/nvim/arglist.c
@@ -13,9 +13,9 @@
 #include "nvim/ascii.h"
 #include "nvim/buffer.h"
 #include "nvim/charset.h"
-#include "nvim/eval.h"
 #include "nvim/eval/typval.h"
 #include "nvim/eval/typval_defs.h"
+#include "nvim/eval/window.h"
 #include "nvim/ex_cmds.h"
 #include "nvim/ex_cmds2.h"
 #include "nvim/ex_cmds_defs.h"
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 67c3307e50..6cb171978b 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -3961,30 +3961,6 @@ char *buf_spname(buf_T *buf)
   return NULL;
 }
 
-/// Find a window for buffer "buf".
-/// If found true is returned and "wp" and "tp" are set to
-/// the window and tabpage.
-/// If not found, false is returned.
-///
-/// @param       buf  buffer to find a window for
-/// @param[out]  wp   stores the found window
-/// @param[out]  tp   stores the found tabpage
-///
-/// @return  true if a window was found for the buffer.
-bool find_win_for_buf(buf_T *buf, win_T **wp, tabpage_T **tp)
-{
-  *wp = NULL;
-  *tp = NULL;
-  FOR_ALL_TAB_WINDOWS(tp2, wp2) {
-    if (wp2->w_buffer == buf) {
-      *tp = tp2;
-      *wp = wp2;
-      return true;
-    }
-  }
-  return false;
-}
-
 static int buf_signcols_inner(buf_T *buf, int maximum)
 {
   sign_entry_T *sign;  // a sign in the sign list
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 89fda1d8f5..dfa9238327 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -16,7 +16,6 @@
 #include "nvim/ascii.h"
 #include "nvim/buffer.h"
 #include "nvim/buffer_defs.h"
-#include "nvim/change.h"
 #include "nvim/channel.h"
 #include "nvim/charset.h"
 #include "nvim/cmdhist.h"
@@ -73,13 +72,11 @@
 #include "nvim/regexp.h"
 #include "nvim/runtime.h"
 #include "nvim/search.h"
-#include "nvim/sign.h"
 #include "nvim/strings.h"
 #include "nvim/tag.h"
 #include "nvim/types.h"
 #include "nvim/ui.h"
 #include "nvim/ui_compositor.h"
-#include "nvim/undo.h"
 #include "nvim/usercmd.h"
 #include "nvim/version.h"
 #include "nvim/vim.h"
@@ -1031,17 +1028,6 @@ void restore_vimvar(int idx, typval_T *save_tv)
   }
 }
 
-/// If there is a window for "curbuf", make it the current window.
-void find_win_for_curbuf(void)
-{
-  for (wininfo_T *wip = curbuf->b_wininfo; wip != NULL; wip = wip->wi_next) {
-    if (wip->wi_win != NULL) {
-      curwin = wip->wi_win;
-      break;
-    }
-  }
-}
-
 /// Evaluate an expression to a list with suggestions.
 /// For the "expr:" part of 'spellsuggest'.
 ///
@@ -4792,19 +4778,6 @@ void assert_error(garray_T *gap)
                         (const char *)gap->ga_data, (ptrdiff_t)gap->ga_len);
 }
 
-/// Find a window: When using a Window ID in any tab page, when using a number
-/// in the current tab page.
-win_T *find_win_by_nr_or_id(typval_T *vp)
-{
-  int nr = (int)tv_get_number_chk(vp, NULL);
-
-  if (nr >= LOWEST_WIN_ID) {
-    return win_id2wp((int)tv_get_number(vp));
-  }
-
-  return find_win_by_nr(vp, NULL);
-}
-
 /// Implementation of map() and filter().
 void filter_map(typval_T *argvars, typval_T *rettv, int map)
 {
@@ -5161,46 +5134,6 @@ theend:
   xfree(trans_name);
 }
 
-/// @return  buffer options, variables and other attributes in a dictionary.
-dict_T *get_buffer_info(buf_T *buf)
-{
-  dict_T *const dict = tv_dict_alloc();
-
-  tv_dict_add_nr(dict, S_LEN("bufnr"), buf->b_fnum);
-  tv_dict_add_str(dict, S_LEN("name"),
-                  buf->b_ffname != NULL ? (const char *)buf->b_ffname : "");
-  tv_dict_add_nr(dict, S_LEN("lnum"),
-                 buf == curbuf ? curwin->w_cursor.lnum : buflist_findlnum(buf));
-  tv_dict_add_nr(dict, S_LEN("linecount"), buf->b_ml.ml_line_count);
-  tv_dict_add_nr(dict, S_LEN("loaded"), buf->b_ml.ml_mfp != NULL);
-  tv_dict_add_nr(dict, S_LEN("listed"), buf->b_p_bl);
-  tv_dict_add_nr(dict, S_LEN("changed"), bufIsChanged(buf));
-  tv_dict_add_nr(dict, S_LEN("changedtick"), buf_get_changedtick(buf));
-  tv_dict_add_nr(dict, S_LEN("hidden"),
-                 buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0);
-
-  // Get a reference to buffer variables
-  tv_dict_add_dict(dict, S_LEN("variables"), buf->b_vars);
-
-  // List of windows displaying this buffer
-  list_T *const windows = tv_list_alloc(kListLenMayKnow);
-  FOR_ALL_TAB_WINDOWS(tp, wp) {
-    if (wp->w_buffer == buf) {
-      tv_list_append_number(windows, (varnumber_T)wp->handle);
-    }
-  }
-  tv_dict_add_list(dict, S_LEN("windows"), windows);
-
-  if (buf->b_signlist != NULL) {
-    // List of signs placed in this buffer
-    tv_dict_add_list(dict, S_LEN("signs"), get_buffer_signs(buf));
-  }
-
-  tv_dict_add_nr(dict, S_LEN("lastused"), buf->b_last_used);
-
-  return dict;
-}
-
 /// Get the line number from VimL object
 ///
 /// @note Unlike tv_get_lnum(), this one supports only "$" special string.
@@ -5224,115 +5157,6 @@ linenr_T tv_get_lnum_buf(const typval_T *const tv, const buf_T *const buf)
   return (linenr_T)tv_get_number_chk(tv, NULL);
 }
 
-/// @return  information (variables, options, etc.) about a tab page
-///          as a dictionary.
-dict_T *get_tabpage_info(tabpage_T *tp, int tp_idx)
-{
-  dict_T *const dict = tv_dict_alloc();
-
-  tv_dict_add_nr(dict, S_LEN("tabnr"), tp_idx);
-
-  list_T *const l = tv_list_alloc(kListLenMayKnow);
-  FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
-    tv_list_append_number(l, (varnumber_T)wp->handle);
-  }
-  tv_dict_add_list(dict, S_LEN("windows"), l);
-
-  // Make a reference to tabpage variables
-  tv_dict_add_dict(dict, S_LEN("variables"), tp->tp_vars);
-
-  return dict;
-}
-
-/// @return  information about a window as a dictionary.
-dict_T *get_win_info(win_T *wp, int16_t tpnr, int16_t winnr)
-{
-  dict_T *const dict = tv_dict_alloc();
-
-  // make sure w_botline is valid
-  validate_botline(wp);
-
-  tv_dict_add_nr(dict, S_LEN("tabnr"), tpnr);
-  tv_dict_add_nr(dict, S_LEN("winnr"), winnr);
-  tv_dict_add_nr(dict, S_LEN("winid"), wp->handle);
-  tv_dict_add_nr(dict, S_LEN("height"), wp->w_height_inner);
-  tv_dict_add_nr(dict, S_LEN("winrow"), wp->w_winrow + 1);
-  tv_dict_add_nr(dict, S_LEN("topline"), wp->w_topline);
-  tv_dict_add_nr(dict, S_LEN("botline"), wp->w_botline - 1);
-  tv_dict_add_nr(dict, S_LEN("winbar"), wp->w_winbar_height);
-  tv_dict_add_nr(dict, S_LEN("width"), wp->w_width_inner);
-  tv_dict_add_nr(dict, S_LEN("bufnr"), wp->w_buffer->b_fnum);
-  tv_dict_add_nr(dict, S_LEN("wincol"), wp->w_wincol + 1);
-  tv_dict_add_nr(dict, S_LEN("textoff"), win_col_off(wp));
-  tv_dict_add_nr(dict, S_LEN("terminal"), bt_terminal(wp->w_buffer));
-  tv_dict_add_nr(dict, S_LEN("quickfix"), bt_quickfix(wp->w_buffer));
-  tv_dict_add_nr(dict, S_LEN("loclist"),
-                 (bt_quickfix(wp->w_buffer) && wp->w_llist_ref != NULL));
-
-  // Add a reference to window variables
-  tv_dict_add_dict(dict, S_LEN("variables"), wp->w_vars);
-
-  return dict;
-}
-
-/// Find window specified by "vp" in tabpage "tp".
-///
-/// @param tp  NULL for current tab page
-win_T *find_win_by_nr(typval_T *vp, tabpage_T *tp)
-{
-  int nr = (int)tv_get_number_chk(vp, NULL);
-
-  if (nr < 0) {
-    return NULL;
-  }
-
-  if (nr == 0) {
-    return curwin;
-  }
-
-  // This method accepts NULL as an alias for curtab.
-  if (tp == NULL) {
-    tp = curtab;
-  }
-
-  FOR_ALL_WINDOWS_IN_TAB(wp, tp) {
-    if (nr >= LOWEST_WIN_ID) {
-      if (wp->handle == nr) {
-        return wp;
-      }
-    } else if (--nr <= 0) {
-      return wp;
-    }
-  }
-  return NULL;
-}
-
-/// Find window specified by "wvp" in tabpage "tvp".
-win_T *find_tabwin(typval_T *wvp, typval_T *tvp)
-{
-  win_T *wp = NULL;
-  tabpage_T *tp = NULL;
-
-  if (wvp->v_type != VAR_UNKNOWN) {
-    if (tvp->v_type != VAR_UNKNOWN) {
-      long n = tv_get_number(tvp);
-      if (n >= 0) {
-        tp = find_tabpage((int)n);
-      }
-    } else {
-      tp = curtab;
-    }
-
-    if (tp != NULL) {
-      wp = find_win_by_nr(wvp, tp);
-    }
-  } else {
-    wp = curwin;
-  }
-
-  return wp;
-}
-
 /// This function is used by f_input() and f_inputdialog() functions. The third
 /// argument to f_input() specifies the type of completion to use at the
 /// prompt. The third argument to f_inputdialog() specifies the value to return
@@ -5554,136 +5378,6 @@ void screenchar_adjust(ScreenGrid **grid, int *row, int *col)
   *col -= (*grid)->comp_col;
 }
 
-/// Set line or list of lines in buffer "buf" to "lines".
-/// Any type is allowed and converted to a string.
-void set_buffer_lines(buf_T *buf, linenr_T lnum_arg, bool append, typval_T *lines, typval_T *rettv)
-  FUNC_ATTR_NONNULL_ARG(4, 5)
-{
-  linenr_T lnum = lnum_arg + (append ? 1 : 0);
-  long added = 0;
-  buf_T *curbuf_save = NULL;
-  win_T *curwin_save = NULL;
-  const bool is_curbuf = buf == curbuf;
-  const bool save_VIsual_active = VIsual_active;
-
-  // When using the current buffer ml_mfp will be set if needed.  Useful when
-  // setline() is used on startup.  For other buffers the buffer must be
-  // loaded.
-  if (buf == NULL || (!is_curbuf && buf->b_ml.ml_mfp == NULL) || lnum < 1) {
-    rettv->vval.v_number = 1;  // FAIL
-    return;
-  }
-
-  if (!is_curbuf) {
-    VIsual_active = false;
-    curbuf_save = curbuf;
-    curwin_save = curwin;
-    curbuf = buf;
-    find_win_for_curbuf();
-  }
-
-  linenr_T append_lnum;
-  if (append) {
-    // appendbufline() uses the line number below which we insert
-    append_lnum = lnum - 1;
-  } else {
-    // setbufline() uses the line number above which we insert, we only
-    // append if it's below the last line
-    append_lnum = curbuf->b_ml.ml_line_count;
-  }
-
-  list_T *l = NULL;
-  listitem_T *li = NULL;
-  char *line = NULL;
-  if (lines->v_type == VAR_LIST) {
-    l = lines->vval.v_list;
-    if (l == NULL || tv_list_len(l) == 0) {
-      // set proper return code
-      if (lnum > curbuf->b_ml.ml_line_count) {
-        rettv->vval.v_number = 1;       // FAIL
-      }
-      goto done;
-    }
-    li = tv_list_first(l);
-  } else {
-    line = typval_tostring(lines, false);
-  }
-
-  // Default result is zero == OK.
-  for (;;) {
-    if (lines->v_type == VAR_LIST) {
-      // List argument, get next string.
-      if (li == NULL) {
-        break;
-      }
-      xfree(line);
-      line = typval_tostring(TV_LIST_ITEM_TV(li), false);
-      li = TV_LIST_ITEM_NEXT(l, li);
-    }
-
-    rettv->vval.v_number = 1;  // FAIL
-    if (line == NULL || lnum > curbuf->b_ml.ml_line_count + 1) {
-      break;
-    }
-
-    // When coming here from Insert mode, sync undo, so that this can be
-    // undone separately from what was previously inserted.
-    if (u_sync_once == 2) {
-      u_sync_once = 1;  // notify that u_sync() was called
-      u_sync(true);
-    }
-
-    if (!append && lnum <= curbuf->b_ml.ml_line_count) {
-      // Existing line, replace it.
-      int old_len = (int)strlen(ml_get(lnum));
-      if (u_savesub(lnum) == OK
-          && ml_replace(lnum, line, true) == OK) {
-        inserted_bytes(lnum, 0, old_len, (int)strlen(line));
-        if (is_curbuf && lnum == curwin->w_cursor.lnum) {
-          check_cursor_col();
-        }
-        rettv->vval.v_number = 0;  // OK
-      }
-    } else if (added > 0 || u_save(lnum - 1, lnum) == OK) {
-      // append the line.
-      added++;
-      if (ml_append(lnum - 1, line, 0, false) == OK) {
-        rettv->vval.v_number = 0;  // OK
-      }
-    }
-
-    if (l == NULL) {  // only one string argument
-      break;
-    }
-    lnum++;
-  }
-  xfree(line);
-
-  if (added > 0) {
-    appended_lines_mark(append_lnum, added);
-
-    // Only adjust the cursor for buffers other than the current, unless it
-    // is the current window. For curbuf and other windows it has been done
-    // in mark_adjust_internal().
-    FOR_ALL_TAB_WINDOWS(tp, wp) {
-      if (wp->w_buffer == buf
-          && (wp->w_buffer != curbuf || wp == curwin)
-          && wp->w_cursor.lnum > append_lnum) {
-        wp->w_cursor.lnum += (linenr_T)added;
-      }
-    }
-    check_cursor_col();
-    update_topline(curwin);
-  }
-
-done:
-  if (!is_curbuf) {
-    curbuf = curbuf_save;
-    curwin = curwin_save;
-    VIsual_active = save_VIsual_active;
-  }
-}
-
 /// "stdpath()" helper for list results
 void get_xdg_var_list(const XDGVarType xdg, typval_T *rettv)
   FUNC_ATTR_NONNULL_ALL
diff --git a/src/nvim/eval/buffer.c b/src/nvim/eval/buffer.c
new file mode 100644
index 0000000000..41ba8d2e88
--- /dev/null
+++ b/src/nvim/eval/buffer.c
@@ -0,0 +1,700 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
+// eval/buffer.c: Buffer related builtin functions
+
+#include <stdbool.h>
+#include <string.h>
+
+#include "nvim/ascii.h"
+#include "nvim/autocmd.h"
+#include "nvim/buffer.h"
+#include "nvim/change.h"
+#include "nvim/cursor.h"
+#include "nvim/eval.h"
+#include "nvim/eval/buffer.h"
+#include "nvim/eval/funcs.h"
+#include "nvim/eval/typval.h"
+#include "nvim/eval/typval_defs.h"
+#include "nvim/globals.h"
+#include "nvim/macros.h"
+#include "nvim/memline.h"
+#include "nvim/memory.h"
+#include "nvim/move.h"
+#include "nvim/path.h"
+#include "nvim/pos.h"
+#include "nvim/sign.h"
+#include "nvim/types.h"
+#include "nvim/undo.h"
+#include "nvim/vim.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "eval/buffer.c.generated.h"
+#endif
+
+/// Find a buffer by number or exact name.
+buf_T *find_buffer(typval_T *avar)
+{
+  buf_T *buf = NULL;
+
+  if (avar->v_type == VAR_NUMBER) {
+    buf = buflist_findnr((int)avar->vval.v_number);
+  } else if (avar->v_type == VAR_STRING && avar->vval.v_string != NULL) {
+    buf = buflist_findname_exp(avar->vval.v_string);
+    if (buf == NULL) {
+      // No full path name match, try a match with a URL or a "nofile"
+      // buffer, these don't use the full path.
+      FOR_ALL_BUFFERS(bp) {
+        if (bp->b_fname != NULL
+            && (path_with_url(bp->b_fname) || bt_nofilename(bp))
+            && strcmp(bp->b_fname, avar->vval.v_string) == 0) {
+          buf = bp;
+          break;
+        }
+      }
+    }
+  }
+  return buf;
+}
+
+/// If there is a window for "curbuf", make it the current window.
+static void find_win_for_curbuf(void)
+{
+  for (wininfo_T *wip = curbuf->b_wininfo; wip != NULL; wip = wip->wi_next) {
+    if (wip->wi_win != NULL) {
+      curwin = wip->wi_win;
+      break;
+    }
+  }
+}
+
+/// Set line or list of lines in buffer "buf" to "lines".
+/// Any type is allowed and converted to a string.
+static void set_buffer_lines(buf_T *buf, linenr_T lnum_arg, bool append, typval_T *lines,
+                             typval_T *rettv)
+  FUNC_ATTR_NONNULL_ARG(4, 5)
+{
+  linenr_T lnum = lnum_arg + (append ? 1 : 0);
+  long added = 0;
+  buf_T *curbuf_save = NULL;
+  win_T *curwin_save = NULL;
+  const bool is_curbuf = buf == curbuf;
+  const bool save_VIsual_active = VIsual_active;
+
+  // When using the current buffer ml_mfp will be set if needed.  Useful when
+  // setline() is used on startup.  For other buffers the buffer must be
+  // loaded.
+  if (buf == NULL || (!is_curbuf && buf->b_ml.ml_mfp == NULL) || lnum < 1) {
+    rettv->vval.v_number = 1;  // FAIL
+    return;
+  }
+
+  if (!is_curbuf) {
+    VIsual_active = false;
+    curbuf_save = curbuf;
+    curwin_save = curwin;
+    curbuf = buf;
+    find_win_for_curbuf();
+  }
+
+  linenr_T append_lnum;
+  if (append) {
+    // appendbufline() uses the line number below which we insert
+    append_lnum = lnum - 1;
+  } else {
+    // setbufline() uses the line number above which we insert, we only
+    // append if it's below the last line
+    append_lnum = curbuf->b_ml.ml_line_count;
+  }
+
+  list_T *l = NULL;
+  listitem_T *li = NULL;
+  char *line = NULL;
+  if (lines->v_type == VAR_LIST) {
+    l = lines->vval.v_list;
+    if (l == NULL || tv_list_len(l) == 0) {
+      // set proper return code
+      if (lnum > curbuf->b_ml.ml_line_count) {
+        rettv->vval.v_number = 1;       // FAIL
+      }
+      goto done;
+    }
+    li = tv_list_first(l);
+  } else {
+    line = typval_tostring(lines, false);
+  }
+
+  // Default result is zero == OK.
+  for (;;) {
+    if (lines->v_type == VAR_LIST) {
+      // List argument, get next string.
+      if (li == NULL) {
+        break;
+      }
+      xfree(line);
+      line = typval_tostring(TV_LIST_ITEM_TV(li), false);
+      li = TV_LIST_ITEM_NEXT(l, li);
+    }
+
+    rettv->vval.v_number = 1;  // FAIL
+    if (line == NULL || lnum > curbuf->b_ml.ml_line_count + 1) {
+      break;
+    }
+
+    // When coming here from Insert mode, sync undo, so that this can be
+    // undone separately from what was previously inserted.
+    if (u_sync_once == 2) {
+      u_sync_once = 1;  // notify that u_sync() was called
+      u_sync(true);
+    }
+
+    if (!append && lnum <= curbuf->b_ml.ml_line_count) {
+      // Existing line, replace it.
+      int old_len = (int)strlen(ml_get(lnum));
+      if (u_savesub(lnum) == OK
+          && ml_replace(lnum, line, true) == OK) {
+        inserted_bytes(lnum, 0, old_len, (int)strlen(line));
+        if (is_curbuf && lnum == curwin->w_cursor.lnum) {
+          check_cursor_col();
+        }
+        rettv->vval.v_number = 0;  // OK
+      }
+    } else if (added > 0 || u_save(lnum - 1, lnum) == OK) {
+      // append the line.
+      added++;
+      if (ml_append(lnum - 1, line, 0, false) == OK) {
+        rettv->vval.v_number = 0;  // OK
+      }
+    }
+
+    if (l == NULL) {  // only one string argument
+      break;
+    }
+    lnum++;
+  }
+  xfree(line);
+
+  if (added > 0) {
+    appended_lines_mark(append_lnum, added);
+
+    // Only adjust the cursor for buffers other than the current, unless it
+    // is the current window. For curbuf and other windows it has been done
+    // in mark_adjust_internal().
+    FOR_ALL_TAB_WINDOWS(tp, wp) {
+      if (wp->w_buffer == buf
+          && (wp->w_buffer != curbuf || wp == curwin)
+          && wp->w_cursor.lnum > append_lnum) {
+        wp->w_cursor.lnum += (linenr_T)added;
+      }
+    }
+    check_cursor_col();
+    update_topline(curwin);
+  }
+
+done:
+  if (!is_curbuf) {
+    curbuf = curbuf_save;
+    curwin = curwin_save;
+    VIsual_active = save_VIsual_active;
+  }
+}
+
+/// "append(lnum, string/list)" function
+void f_append(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  const int did_emsg_before = did_emsg;
+  const linenr_T lnum = tv_get_lnum(&argvars[0]);
+  if (did_emsg == did_emsg_before) {
+    set_buffer_lines(curbuf, lnum, true, &argvars[1], rettv);
+  }
+}
+
+/// Set or append lines to a buffer.
+static void buf_set_append_line(typval_T *argvars, typval_T *rettv, bool append)
+{
+  const int did_emsg_before = did_emsg;
+  buf_T *const buf = tv_get_buf(&argvars[0], false);
+  if (buf == NULL) {
+    rettv->vval.v_number = 1;  // FAIL
+  } else {
+    const linenr_T lnum = tv_get_lnum_buf(&argvars[1], buf);
+    if (did_emsg == did_emsg_before) {
+      set_buffer_lines(buf, lnum, append, &argvars[2], rettv);
+    }
+  }
+}
+
+/// "appendbufline(buf, lnum, string/list)" function
+void f_appendbufline(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_set_append_line(argvars, rettv, true);
+}
+
+/// "bufadd(expr)" function
+void f_bufadd(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  char_u *name = (char_u *)tv_get_string(&argvars[0]);
+
+  rettv->vval.v_number = buflist_add(*name == NUL ? NULL : (char *)name, 0);
+}
+
+/// "bufexists(expr)" function
+void f_bufexists(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  rettv->vval.v_number = (find_buffer(&argvars[0]) != NULL);
+}
+
+/// "buflisted(expr)" function
+void f_buflisted(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_T *buf;
+
+  buf = find_buffer(&argvars[0]);
+  rettv->vval.v_number = (buf != NULL && buf->b_p_bl);
+}
+
+/// "bufload(expr)" function
+void f_bufload(typval_T *argvars, typval_T *unused, EvalFuncData fptr)
+{
+  buf_T *buf = get_buf_arg(&argvars[0]);
+
+  if (buf != NULL && buf->b_ml.ml_mfp == NULL) {
+    aco_save_T aco;
+
+    aucmd_prepbuf(&aco, buf);
+    swap_exists_action = SEA_NONE;
+    open_buffer(false, NULL, 0);
+    aucmd_restbuf(&aco);
+  }
+}
+
+/// "bufloaded(expr)" function
+void f_bufloaded(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_T *buf;
+
+  buf = find_buffer(&argvars[0]);
+  rettv->vval.v_number = (buf != NULL && buf->b_ml.ml_mfp != NULL);
+}
+
+/// "bufname(expr)" function
+void f_bufname(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  const buf_T *buf;
+  rettv->v_type = VAR_STRING;
+  rettv->vval.v_string = NULL;
+  if (argvars[0].v_type == VAR_UNKNOWN) {
+    buf = curbuf;
+  } else {
+    buf = tv_get_buf_from_arg(&argvars[0]);
+  }
+  if (buf != NULL && buf->b_fname != NULL) {
+    rettv->vval.v_string = xstrdup(buf->b_fname);
+  }
+}
+
+/// "bufnr(expr)" function
+void f_bufnr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  const buf_T *buf;
+  bool error = false;
+
+  rettv->vval.v_number = -1;
+
+  if (argvars[0].v_type == VAR_UNKNOWN) {
+    buf = curbuf;
+  } else {
+    // Don't use tv_get_buf_from_arg(); we continue if the buffer wasn't found
+    // and the second argument isn't zero, but we want to return early if the
+    // first argument isn't a string or number so only one error is shown.
+    if (!tv_check_str_or_nr(&argvars[0])) {
+      return;
+    }
+    emsg_off++;
+    buf = tv_get_buf(&argvars[0], false);
+    emsg_off--;
+  }
+
+  // If the buffer isn't found and the second argument is not zero create a
+  // new buffer.
+  const char *name;
+  if (buf == NULL
+      && argvars[1].v_type != VAR_UNKNOWN
+      && tv_get_number_chk(&argvars[1], &error) != 0
+      && !error
+      && (name = tv_get_string_chk(&argvars[0])) != NULL) {
+    buf = buflist_new((char *)name, NULL, 1, 0);
+  }
+
+  if (buf != NULL) {
+    rettv->vval.v_number = buf->b_fnum;
+  }
+}
+
+static void buf_win_common(typval_T *argvars, typval_T *rettv, bool get_nr)
+{
+  const buf_T *const buf = tv_get_buf_from_arg(&argvars[0]);
+  if (buf == NULL) {  // no need to search if invalid arg or buffer not found
+    rettv->vval.v_number = -1;
+    return;
+  }
+
+  int winnr = 0;
+  int winid;
+  bool found_buf = false;
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    winnr++;
+    if (wp->w_buffer == buf) {
+      found_buf = true;
+      winid = wp->handle;
+      break;
+    }
+  }
+  rettv->vval.v_number = (found_buf ? (get_nr ? winnr : winid) : -1);
+}
+
+/// "bufwinid(nr)" function
+void f_bufwinid(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_win_common(argvars, rettv, false);
+}
+
+/// "bufwinnr(nr)" function
+void f_bufwinnr(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_win_common(argvars, rettv, true);
+}
+
+/// "deletebufline()" function
+void f_deletebufline(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  const int did_emsg_before = did_emsg;
+  rettv->vval.v_number = 1;   // FAIL by default
+  buf_T *const buf = tv_get_buf(&argvars[0], false);
+  if (buf == NULL) {
+    return;
+  }
+  const bool is_curbuf = buf == curbuf;
+  const bool save_VIsual_active = VIsual_active;
+
+  linenr_T last;
+  const linenr_T first = tv_get_lnum_buf(&argvars[1], buf);
+  if (did_emsg > did_emsg_before) {
+    return;
+  }
+  if (argvars[2].v_type != VAR_UNKNOWN) {
+    last = tv_get_lnum_buf(&argvars[2], buf);
+  } else {
+    last = first;
+  }
+
+  if (buf->b_ml.ml_mfp == NULL || first < 1
+      || first > buf->b_ml.ml_line_count || last < first) {
+    return;
+  }
+
+  buf_T *curbuf_save = NULL;
+  win_T *curwin_save = NULL;
+  // After this don't use "return", goto "cleanup"!
+  if (!is_curbuf) {
+    VIsual_active = false;
+    curbuf_save = curbuf;
+    curwin_save = curwin;
+    curbuf = buf;
+    find_win_for_curbuf();
+  }
+  if (last > curbuf->b_ml.ml_line_count) {
+    last = curbuf->b_ml.ml_line_count;
+  }
+  const long count = last - first + 1;
+
+  // When coming here from Insert mode, sync undo, so that this can be
+  // undone separately from what was previously inserted.
+  if (u_sync_once == 2) {
+    u_sync_once = 1;  // notify that u_sync() was called
+    u_sync(true);
+  }
+
+  if (u_save(first - 1, last + 1) == FAIL) {
+    goto cleanup;
+  }
+
+  for (linenr_T lnum = first; lnum <= last; lnum++) {
+    ml_delete(first, true);
+  }
+
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (wp->w_buffer == buf) {
+      if (wp->w_cursor.lnum > last) {
+        wp->w_cursor.lnum -= (linenr_T)count;
+      } else if (wp->w_cursor.lnum > first) {
+        wp->w_cursor.lnum = first;
+      }
+      if (wp->w_cursor.lnum > wp->w_buffer->b_ml.ml_line_count) {
+        wp->w_cursor.lnum = wp->w_buffer->b_ml.ml_line_count;
+      }
+    }
+  }
+  check_cursor_col();
+  deleted_lines_mark(first, count);
+  rettv->vval.v_number = 0;  // OK
+
+cleanup:
+  if (!is_curbuf) {
+    curbuf = curbuf_save;
+    curwin = curwin_save;
+    VIsual_active = save_VIsual_active;
+  }
+}
+
+/// @return  buffer options, variables and other attributes in a dictionary.
+static dict_T *get_buffer_info(buf_T *buf)
+{
+  dict_T *const dict = tv_dict_alloc();
+
+  tv_dict_add_nr(dict, S_LEN("bufnr"), buf->b_fnum);
+  tv_dict_add_str(dict, S_LEN("name"),
+                  buf->b_ffname != NULL ? (const char *)buf->b_ffname : "");
+  tv_dict_add_nr(dict, S_LEN("lnum"),
+                 buf == curbuf ? curwin->w_cursor.lnum : buflist_findlnum(buf));
+  tv_dict_add_nr(dict, S_LEN("linecount"), buf->b_ml.ml_line_count);
+  tv_dict_add_nr(dict, S_LEN("loaded"), buf->b_ml.ml_mfp != NULL);
+  tv_dict_add_nr(dict, S_LEN("listed"), buf->b_p_bl);
+  tv_dict_add_nr(dict, S_LEN("changed"), bufIsChanged(buf));
+  tv_dict_add_nr(dict, S_LEN("changedtick"), buf_get_changedtick(buf));
+  tv_dict_add_nr(dict, S_LEN("hidden"),
+                 buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0);
+
+  // Get a reference to buffer variables
+  tv_dict_add_dict(dict, S_LEN("variables"), buf->b_vars);
+
+  // List of windows displaying this buffer
+  list_T *const windows = tv_list_alloc(kListLenMayKnow);
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (wp->w_buffer == buf) {
+      tv_list_append_number(windows, (varnumber_T)wp->handle);
+    }
+  }
+  tv_dict_add_list(dict, S_LEN("windows"), windows);
+
+  if (buf->b_signlist != NULL) {
+    // List of signs placed in this buffer
+    tv_dict_add_list(dict, S_LEN("signs"), get_buffer_signs(buf));
+  }
+
+  tv_dict_add_nr(dict, S_LEN("lastused"), buf->b_last_used);
+
+  return dict;
+}
+
+/// "getbufinfo()" function
+void f_getbufinfo(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
+{
+  buf_T *argbuf = NULL;
+  bool filtered = false;
+  bool sel_buflisted = false;
+  bool sel_bufloaded = false;
+  bool sel_bufmodified = false;
+
+  tv_list_alloc_ret(rettv, kListLenMayKnow);
+
+  // List of all the buffers or selected buffers
+  if (argvars[0].v_type == VAR_DICT) {
+    dict_T *sel_d = argvars[0].vval.v_dict;
+
+    if (sel_d != NULL) {
+      dictitem_T *di;
+
+      filtered = true;
+
+      di = tv_dict_find(sel_d, S_LEN("buflisted"));
+      if (di != NULL && tv_get_number(&di->di_tv)) {
+        sel_buflisted = true;
+      }
+
+      di = tv_dict_find(sel_d, S_LEN("bufloaded"));
+      if (di != NULL && tv_get_number(&di->di_tv)) {
+        sel_bufloaded = true;
+      }
+      di = tv_dict_find(sel_d, S_LEN("bufmodified"));
+      if (di != NULL && tv_get_number(&di->di_tv)) {
+        sel_bufmodified = true;
+      }
+    }
+  } else if (argvars[0].v_type != VAR_UNKNOWN) {
+    // Information about one buffer.  Argument specifies the