Merge remote-tracking branch 'upstream/master' into rahm

1 files changed, 2547 insertions, 0 deletions

diff --git a/src/nvim/mapping.c b/src/nvim/mapping.c
new file mode 100644
index 0000000000..5a11ac686e
--- /dev/null
+++ b/src/nvim/mapping.c
@@ -0,0 +1,2547 @@
+// 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
+
+// mapping.c: Code for mappings and abbreviations.
+
+#include <assert.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "nvim/api/private/converter.h"
+#include "nvim/api/private/helpers.h"
+#include "nvim/ascii.h"
+#include "nvim/assert.h"
+#include "nvim/buffer_defs.h"
+#include "nvim/charset.h"
+#include "nvim/eval.h"
+#include "nvim/eval/typval.h"
+#include "nvim/ex_docmd.h"
+#include "nvim/ex_session.h"
+#include "nvim/func_attr.h"
+#include "nvim/garray.h"
+#include "nvim/getchar.h"
+#include "nvim/keycodes.h"
+#include "nvim/lua/executor.h"
+#include "nvim/mapping.h"
+#include "nvim/mbyte.h"
+#include "nvim/memory.h"
+#include "nvim/message.h"
+#include "nvim/option.h"
+#include "nvim/regexp.h"
+#include "nvim/ui.h"
+#include "nvim/vim.h"
+
+/// List used for abbreviations.
+static mapblock_T *first_abbr = NULL;  // first entry in abbrlist
+
+// Each mapping is put in one of the MAX_MAPHASH hash lists,
+// to speed up finding it.
+static mapblock_T *(maphash[MAX_MAPHASH]) = { 0 };
+
+// Make a hash value for a mapping.
+// "mode" is the lower 4 bits of the State for the mapping.
+// "c1" is the first character of the "lhs".
+// Returns a value between 0 and 255, index in maphash.
+// Put Normal/Visual mode mappings mostly separately from Insert/Cmdline mode.
+#define MAP_HASH(mode, \
+                 c1) (((mode) & \
+                       (MODE_NORMAL | MODE_VISUAL | MODE_SELECT | \
+                        MODE_OP_PENDING | MODE_TERMINAL)) ? (c1) : ((c1) ^ 0x80))
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "mapping.c.generated.h"
+#endif
+
+/// Get the start of the hashed map list for "state" and first character "c".
+mapblock_T *get_maphash_list(int state, int c)
+{
+  return maphash[MAP_HASH(state, c)];
+}
+
+/// Get the buffer-local hashed map list for "state" and first character "c".
+mapblock_T *get_buf_maphash_list(int state, int c)
+{
+  return curbuf->b_maphash[MAP_HASH(state, c)];
+}
+
+/// Retrieve the mapblock at the index either globally or for a certain buffer
+///
+/// @param  index  The index in the maphash[]
+/// @param  buf  The buffer to get the maphash from. NULL for global
+mapblock_T *get_maphash(int index, buf_T *buf)
+    FUNC_ATTR_PURE
+{
+  if (index >= MAX_MAPHASH) {
+    return NULL;
+  }
+
+  return (buf == NULL) ? maphash[index] : buf->b_maphash[index];
+}
+
+/// Delete one entry from the abbrlist or maphash[].
+/// "mpp" is a pointer to the m_next field of the PREVIOUS entry!
+static void mapblock_free(mapblock_T **mpp)
+{
+  mapblock_T *mp;
+
+  mp = *mpp;
+  xfree(mp->m_keys);
+  if (!mp->m_simplified) {
+    NLUA_CLEAR_REF(mp->m_luaref);
+    xfree(mp->m_str);
+    xfree(mp->m_orig_str);
+  }
+  xfree(mp->m_desc);
+  *mpp = mp->m_next;
+  xfree(mp);
+}
+
+/// Return characters to represent the map mode in an allocated string
+///
+/// @return [allocated] NUL-terminated string with characters.
+static char *map_mode_to_chars(int mode)
+  FUNC_ATTR_MALLOC FUNC_ATTR_NONNULL_RET
+{
+  garray_T mapmode;
+
+  ga_init(&mapmode, 1, 7);
+
+  if ((mode & (MODE_INSERT | MODE_CMDLINE)) == (MODE_INSERT | MODE_CMDLINE)) {
+    ga_append(&mapmode, '!');                           // :map!
+  } else if (mode & MODE_INSERT) {
+    ga_append(&mapmode, 'i');                           // :imap
+  } else if (mode & MODE_LANGMAP) {
+    ga_append(&mapmode, 'l');                           // :lmap
+  } else if (mode & MODE_CMDLINE) {
+    ga_append(&mapmode, 'c');                           // :cmap
+  } else if ((mode & (MODE_NORMAL | MODE_VISUAL | MODE_SELECT | MODE_OP_PENDING))
+             == (MODE_NORMAL | MODE_VISUAL | MODE_SELECT | MODE_OP_PENDING)) {
+    ga_append(&mapmode, ' ');                           // :map
+  } else {
+    if (mode & MODE_NORMAL) {
+      ga_append(&mapmode, 'n');                         // :nmap
+    }
+    if (mode & MODE_OP_PENDING) {
+      ga_append(&mapmode, 'o');                         // :omap
+    }
+    if (mode & MODE_TERMINAL) {
+      ga_append(&mapmode, 't');                         // :tmap
+    }
+    if ((mode & (MODE_VISUAL | MODE_SELECT)) == (MODE_VISUAL | MODE_SELECT)) {
+      ga_append(&mapmode, 'v');                         // :vmap
+    } else {
+      if (mode & MODE_VISUAL) {
+        ga_append(&mapmode, 'x');                       // :xmap
+      }
+      if (mode & MODE_SELECT) {
+        ga_append(&mapmode, 's');                       // :smap
+      }
+    }
+  }
+
+  ga_append(&mapmode, NUL);
+  return (char *)mapmode.ga_data;
+}
+
+/// @param local  true for buffer-local map
+static void showmap(mapblock_T *mp, bool local)
+{
+  size_t len = 1;
+
+  if (message_filtered(mp->m_keys) && message_filtered(mp->m_str)
+      && (mp->m_desc == NULL || message_filtered((char_u *)mp->m_desc))) {
+    return;
+  }
+
+  if (msg_didout || msg_silent != 0) {
+    msg_putchar('\n');
+    if (got_int) {          // 'q' typed at MORE prompt
+      return;
+    }
+  }
+
+  {
+    char *const mapchars = map_mode_to_chars(mp->m_mode);
+    msg_puts(mapchars);
+    len = strlen(mapchars);
+    xfree(mapchars);
+  }
+
+  while (++len <= 3) {
+    msg_putchar(' ');
+  }
+
+  // Display the LHS.  Get length of what we write.
+  len = (size_t)msg_outtrans_special(mp->m_keys, true, 0);
+  do {
+    msg_putchar(' ');                   // padd with blanks
+    len++;
+  } while (len < 12);
+
+  if (mp->m_noremap == REMAP_NONE) {
+    msg_puts_attr("*", HL_ATTR(HLF_8));
+  } else if (mp->m_noremap == REMAP_SCRIPT) {
+    msg_puts_attr("&", HL_ATTR(HLF_8));
+  } else {
+    msg_putchar(' ');
+  }
+
+  if (local) {
+    msg_putchar('@');
+  } else {
+    msg_putchar(' ');
+  }
+
+  // Use false below if we only want things like <Up> to show up as such on
+  // the rhs, and not M-x etc, true gets both -- webb
+  if (mp->m_luaref != LUA_NOREF) {
+    char msg[100];
+    snprintf(msg, sizeof(msg), "<Lua function %d>", mp->m_luaref);
+    msg_puts_attr(msg, HL_ATTR(HLF_8));
+  } else if (mp->m_str[0] == NUL) {
+    msg_puts_attr("<Nop>", HL_ATTR(HLF_8));
+  } else {
+    msg_outtrans_special(mp->m_str, false, 0);
+  }
+
+  if (mp->m_desc != NULL) {
+    msg_puts("\n                 ");  // Shift line to same level as rhs.
+    msg_puts(mp->m_desc);
+  }
+  if (p_verbose > 0) {
+    last_set_msg(mp->m_script_ctx);
+  }
+  msg_clr_eos();
+  ui_flush();                          // show one line at a time
+}
+
+/// Replace termcodes in the given LHS and RHS and store the results into the
+/// `lhs` and `rhs` of the given @ref MapArguments struct.
+///
+/// `rhs` and `orig_rhs` will both point to new allocated buffers. `orig_rhs`
+/// will hold a copy of the given `orig_rhs`.
+///
+/// The `*_len` variables will be set appropriately. If the length of
+/// the final `lhs` exceeds `MAXMAPLEN`, `lhs_len` will be set equal to the
+/// original larger length and `lhs` will be truncated.
+///
+/// If RHS should be <Nop>, `rhs` will be an empty string, `rhs_len` will be
+/// zero, and `rhs_is_noop` will be set to true.
+///
+/// Any memory allocated by @ref replace_termcodes is freed before this function
+/// returns.
+///
+/// @param[in] orig_lhs   Original mapping LHS, with characters to replace.
+/// @param[in] orig_lhs_len   `strlen` of orig_lhs.
+/// @param[in] orig_rhs   Original mapping RHS, with characters to replace.
+/// @param[in] rhs_lua   Lua reference for Lua maps.
+/// @param[in] orig_rhs_len   `strlen` of orig_rhs.
+/// @param[in] cpo_flags  See param docs for @ref replace_termcodes.
+/// @param[out] mapargs   MapArguments struct holding the replaced strings.
+static bool set_maparg_lhs_rhs(const char *const orig_lhs, const size_t orig_lhs_len,
+                               const char *const orig_rhs, const size_t orig_rhs_len,
+                               const LuaRef rhs_lua, const int cpo_flags,
+                               MapArguments *const mapargs)
+{
+  char lhs_buf[128];
+
+  // If mapping has been given as ^V<C_UP> say, then replace the term codes
+  // with the appropriate two bytes. If it is a shifted special key, unshift
+  // it too, giving another two bytes.
+  //
+  // replace_termcodes() may move the result to allocated memory, which
+  // needs to be freed later (*lhs_buf and *rhs_buf).
+  // replace_termcodes() also removes CTRL-Vs and sometimes backslashes.
+  // If something like <C-H> is simplified to 0x08 then mark it as simplified.
+  bool did_simplify = false;
+  const int flags = REPTERM_FROM_PART | REPTERM_DO_LT;
+  char *bufarg = lhs_buf;
+  char *replaced = replace_termcodes(orig_lhs, orig_lhs_len, &bufarg, flags, &did_simplify,
+                                     cpo_flags);
+  if (replaced == NULL) {
+    return false;
+  }
+  mapargs->lhs_len = STRLEN(replaced);
+  STRLCPY(mapargs->lhs, replaced, sizeof(mapargs->lhs));
+  if (did_simplify) {
+    replaced = replace_termcodes(orig_lhs, orig_lhs_len, &bufarg, flags | REPTERM_NO_SIMPLIFY,
+                                 NULL, cpo_flags);
+    if (replaced == NULL) {
+      return false;
+    }
+    mapargs->alt_lhs_len = STRLEN(replaced);
+    STRLCPY(mapargs->alt_lhs, replaced, sizeof(mapargs->alt_lhs));
+  } else {
+    mapargs->alt_lhs_len = 0;
+  }
+
+  mapargs->rhs_lua = rhs_lua;
+
+  if (rhs_lua == LUA_NOREF) {
+    mapargs->orig_rhs_len = orig_rhs_len;
+    mapargs->orig_rhs = xcalloc(mapargs->orig_rhs_len + 1, sizeof(char_u));
+    STRLCPY(mapargs->orig_rhs, orig_rhs, mapargs->orig_rhs_len + 1);
+
+    if (STRICMP(orig_rhs, "<nop>") == 0) {  // "<Nop>" means nothing
+      mapargs->rhs = xcalloc(1, sizeof(char_u));  // single null-char
+      mapargs->rhs_len = 0;
+      mapargs->rhs_is_noop = true;
+    } else {
+      char *rhs_buf = NULL;
+      replaced = replace_termcodes(orig_rhs, orig_rhs_len, &rhs_buf, REPTERM_DO_LT, NULL,
+                                   cpo_flags);
+      mapargs->rhs_len = STRLEN(replaced);
+      // XXX: replace_termcodes may produce an empty string even if orig_rhs is non-empty
+      // (e.g. a single ^V, see :h map-empty-rhs)
+      mapargs->rhs_is_noop = orig_rhs_len != 0 && mapargs->rhs_len == 0;
+      mapargs->rhs = (char_u *)replaced;
+    }
+  } else {
+    char tmp_buf[64];
+    // orig_rhs is not used for Lua mappings, but still needs to be a string.
+    mapargs->orig_rhs = xcalloc(1, sizeof(char_u));
+    mapargs->orig_rhs_len = 0;
+    // stores <lua>ref_no<cr> in map_str
+    mapargs->rhs_len = (size_t)vim_snprintf(S_LEN(tmp_buf), "%c%c%c%d\r", K_SPECIAL,
+                                            (char_u)KS_EXTRA, KE_LUA, rhs_lua);
+    mapargs->rhs = vim_strsave((char_u *)tmp_buf);
+  }
+  return true;
+}
+
+/// Parse a string of |:map-arguments| into a @ref MapArguments struct.
+///
+/// Termcodes, backslashes, CTRL-V's, etc. inside the extracted {lhs} and
+/// {rhs} are replaced by @ref set_maparg_lhs_rhs.
+///
+/// rhs and orig_rhs in the returned mapargs will be set to null or a pointer
+/// to allocated memory and should be freed even on error.
+///
+/// @param[in]  strargs   String of map args, e.g. "<buffer> <expr><silent>".
+///                       May contain leading or trailing whitespace.
+/// @param[in]  is_unmap  True, if strargs should be parsed like an |:unmap|
+///                       command. |:unmap| commands interpret *all* text to the
+///                       right of the last map argument as the {lhs} of the
+///                       mapping, i.e. a literal ' ' character is treated like
+///                       a "<space>", rather than separating the {lhs} from the
+///                       {rhs}.
+/// @param[out] mapargs   MapArguments struct holding all extracted argument
+///                       values.
+/// @return 0 on success, 1 if invalid arguments are detected.
+static int str_to_mapargs(const char_u *strargs, bool is_unmap, MapArguments *mapargs)
+{
+  const char_u *to_parse = strargs;
+  to_parse = (char_u *)skipwhite((char *)to_parse);
+  memset(mapargs, 0, sizeof(*mapargs));
+
+  // Accept <buffer>, <nowait>, <silent>, <expr>, <script>, and <unique> in
+  // any order.
+  while (true) {
+    if (STRNCMP(to_parse, "<buffer>", 8) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 8);
+      mapargs->buffer = true;
+      continue;
+    }
+
+    if (STRNCMP(to_parse, "<nowait>", 8) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 8);
+      mapargs->nowait = true;
+      continue;
+    }
+
+    if (STRNCMP(to_parse, "<silent>", 8) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 8);
+      mapargs->silent = true;
+      continue;
+    }
+
+    // Ignore obsolete "<special>" modifier.
+    if (STRNCMP(to_parse, "<special>", 9) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 9);
+      continue;
+    }
+
+    if (STRNCMP(to_parse, "<script>", 8) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 8);
+      mapargs->script = true;
+      continue;
+    }
+
+    if (STRNCMP(to_parse, "<expr>", 6) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 6);
+      mapargs->expr = true;
+      continue;
+    }
+
+    if (STRNCMP(to_parse, "<unique>", 8) == 0) {
+      to_parse = (char_u *)skipwhite((char *)to_parse + 8);
+      mapargs->unique = true;
+      continue;
+    }
+    break;
+  }
+
+  // Find the next whitespace character, call that the end of {lhs}.
+  //
+  // If a character (e.g. whitespace) is immediately preceded by a CTRL-V,
+  // "scan past" that character, i.e. don't "terminate" LHS with that character
+  // if it's whitespace.
+  //
+  // Treat backslash like CTRL-V when 'cpoptions' does not contain 'B'.
+  //
+  // With :unmap, literal white space is included in the {lhs}; there is no
+  // separate {rhs}.
+  const char *lhs_end = (char *)to_parse;
+  bool do_backslash = (vim_strchr(p_cpo, CPO_BSLASH) == NULL);
+  while (*lhs_end && (is_unmap || !ascii_iswhite(*lhs_end))) {
+    if ((lhs_end[0] == Ctrl_V || (do_backslash && lhs_end[0] == '\\'))
+        && lhs_end[1] != NUL) {
+      lhs_end++;  // skip CTRL-V or backslash
+    }
+    lhs_end++;
+  }
+
+  // {lhs_end} is a pointer to the "terminating whitespace" after {lhs}.
+  // Use that to initialize {rhs_start}.
+  const char_u *rhs_start = (char_u *)skipwhite((char *)lhs_end);
+
+  // Given {lhs} might be larger than MAXMAPLEN before replace_termcodes
+  // (e.g. "<Space>" is longer than ' '), so first copy into a buffer.
+  size_t orig_lhs_len = (size_t)((char_u *)lhs_end - to_parse);
+  if (orig_lhs_len >= 256) {
+    return 1;
+  }
+  char_u lhs_to_replace[256];
+  STRLCPY(lhs_to_replace, to_parse, orig_lhs_len + 1);
+
+  size_t orig_rhs_len = STRLEN(rhs_start);
+  if (!set_maparg_lhs_rhs((char *)lhs_to_replace, orig_lhs_len,
+                          (char *)rhs_start, orig_rhs_len, LUA_NOREF,
+                          CPO_TO_CPO_FLAGS, mapargs)) {
+    return 1;
+  }
+
+  if (mapargs->lhs_len > MAXMAPLEN) {
+    return 1;
+  }
+  return 0;
+}
+
+/// Sets or removes a mapping or abbreviation in buffer `buf`.
+///
+/// @param maptype    @see do_map
+/// @param args  Fully parsed and "preprocessed" arguments for the
+///              (un)map/abbrev command. Termcodes should have already been
+///              replaced; whitespace, `<` and `>` signs, etc. in {lhs} and
+///              {rhs} are assumed to be literal components of the mapping.
+/// @param mode       @see do_map
+/// @param is_abbrev  @see do_map
+/// @param buf        Target Buffer
+static int buf_do_map(int maptype, MapArguments *args, int mode, bool is_abbrev, buf_T *buf)
+{
+  mapblock_T *mp, **mpp;
+  const char_u *p;
+  int n;
+  int retval = 0;
+  mapblock_T **abbr_table;
+  mapblock_T **map_table;
+  int noremap;
+
+  map_table = maphash;
+  abbr_table = &first_abbr;
+
+  // For ":noremap" don't remap, otherwise do remap.
+  if (maptype == 2) {
+    noremap = REMAP_NONE;
+  } else {
+    noremap = REMAP_YES;
+  }
+
+  if (args->buffer) {
+    // If <buffer> was given, we'll be searching through the buffer's
+    // mappings/abbreviations, not the globals.
+    map_table = buf->b_maphash;
+    abbr_table = &buf->b_first_abbr;
+  }
+  if (args->script) {
+    noremap = REMAP_SCRIPT;
+  }
+
+  const bool has_lhs = (args->lhs[0] != NUL);
+  const bool has_rhs = args->rhs_lua != LUA_NOREF || (args->rhs[0] != NUL) || args->rhs_is_noop;
+  const bool do_print = !has_lhs || (maptype != 1 && !has_rhs);
+
+  // check for :unmap without argument
+  if (maptype == 1 && !has_lhs) {
+    retval = 1;
+    goto theend;
+  }
+
+  const char_u *lhs = (char_u *)&args->lhs;
+  const bool did_simplify = args->alt_lhs_len != 0;
+
+  // The following is done twice if we have two versions of keys
+  for (int keyround = 1; keyround <= 2; keyround++) {
+    bool did_it = false;
+    bool did_local = false;
+    bool keyround1_simplified = keyround == 1 && did_simplify;
+    int len = (int)args->lhs_len;
+
+    if (keyround == 2) {
+      if (!did_simplify) {
+        break;
+      }
+      lhs = (char_u *)&args->alt_lhs;
+      len = (int)args->alt_lhs_len;
+    } else if (did_simplify && do_print) {
+      // when printing always use the not-simplified map
+      lhs = (char_u *)&args->alt_lhs;
+      len = (int)args->alt_lhs_len;
+    }
+
+    // check arguments and translate function keys
+    if (has_lhs) {
+      if (len > MAXMAPLEN) {
+        retval = 1;
+        goto theend;
+      }
+
+      if (is_abbrev && maptype != 1) {
+        //
+        // If an abbreviation ends in a keyword character, the
+        // rest must be all keyword-char or all non-keyword-char.
+        // Otherwise we won't be able to find the start of it in a
+        // vi-compatible way.
+        //
+        int same = -1;
+
+        const int first = vim_iswordp(lhs);
+        int last = first;
+        p = lhs + utfc_ptr2len((char *)lhs);
+        n = 1;
+        while (p < lhs + len) {
+          n++;                                  // nr of (multi-byte) chars
+          last = vim_iswordp(p);                // type of last char
+          if (same == -1 && last != first) {
+            same = n - 1;                       // count of same char type
+          }
+          p += utfc_ptr2len((char *)p);
+        }
+        if (last && n > 2 && same >= 0 && same < n - 1) {
+          retval = 1;
+          goto theend;
+        }
+        // An abbreviation cannot contain white space.
+        for (n = 0; n < len; n++) {
+          if (ascii_iswhite(lhs[n])) {
+            retval = 1;
+            goto theend;
+          }
+        }  // for
+      }
+    }
+
+    if (has_lhs && has_rhs && is_abbrev) {  // if we will add an abbreviation,
+      no_abbr = false;  // reset flag that indicates there are no abbreviations
+    }
+
+    if (do_print) {
+      msg_start();
+    }
+
+    // Check if a new local mapping wasn't already defined globally.
+    if (args->unique && map_table == buf->b_maphash && has_lhs && has_rhs && maptype != 1) {
+      // need to loop over all global hash lists
+      for (int hash = 0; hash < 256 && !got_int; hash++) {
+        if (is_abbrev) {
+          if (hash != 0) {  // there is only one abbreviation list
+            break;
+          }
+          mp = first_abbr;
+        } else {
+          mp = maphash[hash];
+        }
+        for (; mp != NULL && !got_int; mp = mp->m_next) {
+          // check entries with the same mode
+          if ((mp->m_mode & mode) != 0
+              && mp->m_keylen == len
+              && STRNCMP(mp->m_keys, lhs, (size_t)len) == 0) {
+            if (is_abbrev) {
+              semsg(_("E224: global abbreviation already exists for %s"),
+                    mp->m_keys);
+            } else {
+              semsg(_("E225: global mapping already exists for %s"), mp->m_keys);
+            }
+            retval = 5;
+            goto theend;
+          }
+        }
+      }
+    }
+
+    // When listing global mappings, also list buffer-local ones here.
+    if (map_table != buf->b_maphash && !has_rhs && maptype != 1) {
+      // need to loop over all global hash lists
+      for (int hash = 0; hash < 256 && !got_int; hash++) {
+        if (is_abbrev) {
+          if (hash != 0) {  // there is only one abbreviation list
+            break;
+          }
+          mp = buf->b_first_abbr;
+        } else {
+          mp = buf->b_maphash[hash];
+        }
+        for (; mp != NULL && !got_int; mp = mp->m_next) {
+          // check entries with the same mode
+          if (!mp->m_simplified && (mp->m_mode & mode) != 0) {
+            if (!has_lhs) {  // show all entries
+              showmap(mp, true);
+              did_local = true;
+            } else {
+              n = mp->m_keylen;
+              if (STRNCMP(mp->m_keys, lhs, (size_t)(n < len ? n : len)) == 0) {
+                showmap(mp, true);
+                did_local = true;
+              }
+            }
+          }
+        }
+      }
+    }
+
+    // Find an entry in the maphash[] list that matches.
+    // For :unmap we may loop two times: once to try to unmap an entry with a
+    // matching 'from' part, a second time, if the first fails, to unmap an
+    // entry with a matching 'to' part. This was done to allow ":ab foo bar"
+    // to be unmapped by typing ":unab foo", where "foo" will be replaced by
+    // "bar" because of the abbreviation.
+    for (int round = 0; (round == 0 || maptype == 1) && round <= 1
+         && !did_it && !got_int; round++) {
+      int hash_start, hash_end;
+      if (has_lhs || is_abbrev) {
+        // just use one hash
+        hash_start = is_abbrev ? 0 : MAP_HASH(mode, lhs[0]);
+        hash_end = hash_start + 1;
+      } else {
+        // need to loop over all hash lists
+        hash_start = 0;
+        hash_end = 256;
+      }
+      for (int hash = hash_start; hash < hash_end && !got_int; hash++) {
+        mpp = is_abbrev ?  abbr_table :  &(map_table[hash]);
+        for (mp = *mpp; mp != NULL && !got_int; mp = *mpp) {
+          if ((mp->m_mode & mode) == 0) {
+            // skip entries with wrong mode
+            mpp = &(mp->m_next);
+            continue;
+          }
+          if (!has_lhs) {                      // show all entries
+            if (!mp->m_simplified) {
+              showmap(mp, map_table != maphash);
+              did_it = true;
+            }
+          } else {                          // do we have a match?
+            if (round) {              // second round: Try unmap "rhs" string
+              n = (int)STRLEN(mp->m_str);
+              p = mp->m_str;
+            } else {
+              n = mp->m_keylen;
+              p = mp->m_keys;
+            }
+            if (STRNCMP(p, lhs, (size_t)(n < len ? n : len)) == 0) {
+              if (maptype == 1) {
+                // Delete entry.
+                // Only accept a full match.  For abbreviations
+                // we ignore trailing space when matching with
+                // the "lhs", since an abbreviation can't have
+                // trailing space.
+                if (n != len && (!is_abbrev || round || n > len
+                                 || *skipwhite((char *)lhs + n) != NUL)) {
+                  mpp = &(mp->m_next);
+                  continue;
+                }
+                // In keyround for simplified keys, don't unmap
+                // a mapping without m_simplified flag.
+                if (keyround1_simplified && !mp->m_simplified) {
+                  break;
+                }
+                // We reset the indicated mode bits. If nothing
+                // is left the entry is deleted below.
+                mp->m_mode &= ~mode;
+                did_it = true;  // remember we did something
+              } else if (!has_rhs) {  // show matching entry
+                if (!mp->m_simplified) {
+                  showmap(mp, map_table != maphash);
+                  did_it = true;
+                }
+              } else if (n != len) {  // new entry is ambiguous
+                mpp = &(mp->m_next);
+                continue;
+              } else if (keyround1_simplified && !mp->m_simplified) {
+                // In keyround for simplified keys, don't replace
+                // a mapping without m_simplified flag.
+                did_it = true;
+                break;
+              } else if (args->unique) {
+                if (is_abbrev) {
+                  semsg(_("E226: abbreviation already exists for %s"), p);
+                } else {
+                  semsg(_("E227: mapping already exists for %s"), p);
+                }
+                retval = 5;
+                goto theend;
+              } else {
+                // new rhs for existing entry
+                mp->m_mode &= ~mode;  // remove mode bits
+                if (mp->m_mode == 0 && !did_it) {  // reuse entry
+                  XFREE_CLEAR(mp->m_desc);
+                  if (!mp->m_simplified) {
+                    NLUA_CLEAR_REF(mp->m_luaref);
+                    XFREE_CLEAR(mp->m_str);
+                    XFREE_CLEAR(mp->m_orig_str);
+                  }
+                  mp->m_str = args->rhs;
+                  mp->m_orig_str = args->orig_rhs;
+                  mp->m_luaref = args->rhs_lua;
+                  if (!keyround1_simplified) {
+                    args->rhs = NULL;
+                    args->orig_rhs = NULL;
+                    args->rhs_lua = LUA_NOREF;
+                  }
+                  mp->m_noremap = noremap;
+                  mp->m_nowait = args->nowait;
+                  mp->m_silent = args->silent;
+                  mp->m_mode = mode;
+                  mp->m_simplified = keyround1_simplified;
+                  mp->m_expr = args->expr;
+                  mp->m_script_ctx = current_sctx;
+                  mp->m_script_ctx.sc_lnum += sourcing_lnum;
+                  nlua_set_sctx(&mp->m_script_ctx);
+                  if (args->desc != NULL) {
+                    mp->m_desc = xstrdup(args->desc);
+                  }
+                  did_it = true;
+                }
+              }
+              if (mp->m_mode == 0) {  // entry can be deleted
+                mapblock_free(mpp);
+                continue;  // continue with *mpp
+              }
+
+              // May need to put this entry into another hash list.
+              int new_hash = MAP_HASH(mp->m_mode, mp->m_keys[0]);
+              if (!is_abbrev && new_hash != hash) {
+                *mpp = mp->m_next;
+                mp->m_next = map_table[new_hash];
+                map_table[new_hash] = mp;
+
+                continue;  // continue with *mpp
+              }
+            }
+          }
+          mpp = &(mp->m_next);
+        }
+      }
+    }
+
+    if (maptype == 1) {
+      // delete entry
+      if (!did_it) {
+        if (!keyround1_simplified) {
+          retval = 2;  // no match
+        }
+      } else if (*lhs == Ctrl_C) {
+        // If CTRL-C has been unmapped, reuse it for Interrupting.
+        if (map_table == buf->b_maphash) {
+          buf->b_mapped_ctrl_c &= ~mode;
+        } else {
+          mapped_ctrl_c &= ~mode;
+        }
+      }
+      continue;
+    }
+
+    if (!has_lhs || !has_rhs) {
+      // print entries
+      if (!did_it && !did_local) {
+        if (is_abbrev) {
+          msg(_("No abbreviation found"));
+        } else {
+          msg(_("No mapping found"));
+        }
+      }
+      goto theend;  // listing finished
+    }
+
+    if (did_it) {
+      continue;  // have added the new entry already
+    }
+
+    // Get here when adding a new entry to the maphash[] list or abbrlist.
+    mp = xmalloc(sizeof(mapblock_T));
+
+    // If CTRL-C has been mapped, don't always use it for Interrupting.
+    if (*lhs == Ctrl_C) {
+      if (map_table == buf->b_maphash) {
+        buf->b_mapped_ctrl_c |= mode;
+      } else {
+        mapped_ctrl_c |= mode;
+      }
+    }
+
+    mp->m_keys = vim_strsave(lhs);
+    mp->m_str = args->rhs;
+    mp->m_orig_str = args->orig_rhs;
+    mp->m_luaref = args->rhs_lua;
+    if (!keyround1_simplified) {
+      args->rhs = NULL;
+      args->orig_rhs = NULL;
+      args->rhs_lua = LUA_NOREF;
+    }
+    mp->m_keylen = (int)STRLEN(mp->m_keys);
+    mp->m_noremap = noremap;
+    mp->m_nowait = args->nowait;
+    mp->m_silent = args->silent;
+    mp->m_mode = mode;
+    mp->m_simplified = keyround1_simplified;  // Notice this when porting patch 8.2.0807
+    mp->m_expr = args->expr;
+    mp->m_script_ctx = current_sctx;
+    mp->m_script_ctx.sc_lnum += sourcing_lnum;
+    nlua_set_sctx(&mp->m_script_ctx);
+    mp->m_desc = NULL;
+    if (args->desc != NULL) {
+      mp->m_desc = xstrdup(args->desc);
+    }
+
+    // add the new entry in front of the abbrlist or maphash[] list
+    if (is_abbrev) {
+      mp->m_next = *abbr_table;
+      *abbr_table = mp;
+    } else {
+      n = MAP_HASH(mp->m_mode, mp->m_keys[0]);
+      mp->m_next = map_table[n];
+      map_table[n] = mp;
+    }
+  }
+
+theend:
+  return retval;
+}
+
+/// Set or remove a mapping or an abbreviation in the current buffer, OR
+/// display (matching) mappings/abbreviations.
+///
+/// ```vim
+/// map[!]                          " show all key mappings
+/// map[!] {lhs}                    " show key mapping for {lhs}
+/// map[!] {lhs} {rhs}              " set key mapping for {lhs} to {rhs}
+/// noremap[!] {lhs} {rhs}          " same, but no remapping for {rhs}
+/// unmap[!] {lhs}                  " remove key mapping for {lhs}
+/// abbr                            " show all abbreviations
+/// abbr {lhs}                      " show abbreviations for {lhs}
+/// abbr {lhs} {rhs}                " set abbreviation for {lhs} to {rhs}
+/// noreabbr {lhs} {rhs}            " same, but no remapping for {rhs}
+/// unabbr {lhs}                    " remove abbreviation for {lhs}
+///
+/// for :map   mode is MODE_NORMAL | MODE_VISUAL | MODE_SELECT | MODE_OP_PENDING
+/// for :map!  mode is MODE_INSERT | MODE_CMDLINE
+/// for :cmap  mode is MODE_CMDLINE
+/// for :imap  mode is MODE_INSERT
+/// for :lmap  mode is MODE_LANGMAP
+/// for :nmap  mode is MODE_NORMAL
+/// for :vmap  mode is MODE_VISUAL | MODE_SELECT
+/// for :xmap  mode is MODE_VISUAL
+/// for :smap  mode is MODE_SELECT
+/// for :omap  mode is MODE_OP_PENDING
+/// for :tmap  mode is MODE_TERMINAL
+///
+/// for :abbr  mode is MODE_INSERT | MODE_CMDLINE
+/// for :iabbr mode is MODE_INSERT
+/// for :cabbr mode is MODE_CMDLINE
+/// ```
+///
+/// @param maptype  0 for |:map|, 1 for |:unmap|, 2 for |noremap|.
+/// @param arg      C-string containing the arguments of the map/abbrev
+///                 command, i.e. everything except the initial `:[X][nore]map`.
+///                 - Cannot be a read-only string; it will be modified.
+/// @param mode   Bitflags representing the mode in which to set the mapping.
+///               See @ref get_map_mode.
+/// @param is_abbrev  True if setting an abbreviation, false otherwise.
+///
+/// @return 0 on success. On failure, will return one of the following:
+///         - 1 for invalid arguments
+///         - 2 for no match
+///         - 4 for out of mem (deprecated, WON'T HAPPEN)
+///         - 5 for entry not unique
+///
+int do_map(int maptype, char_u *arg, int mode, bool is_abbrev)
+{
+  MapArguments parsed_args;
+  int result = str_to_mapargs(arg, maptype == 1, &parsed_args);
+  switch (result) {
+  case 0:
+    break;
+  case 1:
+    // invalid arguments
+    goto free_and_return;
+  default:
+    assert(false && "Unknown return code from str_to_mapargs!");
+    result = -1;
+    goto free_and_return;
+  }  // switch
+
+  result = buf_do_map(maptype, &parsed_args, mode, is_abbrev, curbuf);
+
+free_and_return:
+  xfree(parsed_args.rhs);
+  xfree(parsed_args.orig_rhs);
+  return result;
+}
+
+/// Get the mapping mode from the command name.
+static int get_map_mode(char **cmdp, bool forceit)
+{
+  char *p;
+  int modec;
+  int mode;
+
+  p = *cmdp;
+  modec = (uint8_t)(*p++);
+  if (modec == 'i') {
+    mode = MODE_INSERT;                                                  // :imap
+  } else if (modec == 'l') {
+    mode = MODE_LANGMAP;                                                 // :lmap
+  } else if (modec == 'c') {
+    mode = MODE_CMDLINE;                                                 // :cmap
+  } else if (modec == 'n' && *p != 'o') {  // avoid :noremap
+    mode = MODE_NORMAL;                                                  // :nmap
+  } else if (modec == 'v') {
+    mode = MODE_VISUAL | MODE_SELECT;                                    // :vmap
+  } else if (modec == 'x') {
+    mode = MODE_VISUAL;                                                  // :xmap
+  } else if (modec == 's') {
+    mode = MODE_SELECT;                                                  // :smap
+  } else if (modec == 'o') {
+    mode = MODE_OP_PENDING;                                              // :omap
+  } else if (modec == 't') {
+    mode = MODE_TERMINAL;                                                // :tmap
+  } else {
+    p--;
+    if (forceit) {
+      mode = MODE_INSERT | MODE_CMDLINE;                                 // :map !
+    } else {
+      mode = MODE_VISUAL | MODE_SELECT | MODE_NORMAL | MODE_OP_PENDING;  // :map
+    }
+  }
+
+  *cmdp = p;
+  return mode;
+}
+
+/// Clear all mappings (":mapclear") or abbreviations (":abclear").
+/// "abbr" should be false for mappings, true for abbreviations.
+/// This function used to be called map_clear().
+static void do_mapclear(char_u *cmdp, char_u *arg, int forceit, int abbr)
+{
+  int mode;
+  int local;
+
+  local = (STRCMP(arg, "<buffer>") == 0);
+  if (!local && *arg != NUL) {
+    emsg(_(e_invarg));
+    return;
+  }
+
+  mode = get_map_mode((char **)&cmdp, forceit);
+  map_clear_mode(curbuf, mode, local, abbr);
+}
+
+/// Clear all mappings in "mode".
+///
+/// @param buf,  buffer for local mappings
+/// @param mode  mode in which to delete
+/// @param local  true for buffer-local mappings
+/// @param abbr  true for abbreviations
+void map_clear_mode(buf_T *buf, int mode, bool local, bool abbr)
+{
+  mapblock_T *mp, **mpp;
+  int hash;
+  int new_hash;
+
+  for (hash = 0; hash < 256; hash++) {
+    if (abbr) {
+      if (hash > 0) {           // there is only one abbrlist
+        break;
+      }
+      if (local) {
+        mpp = &buf->b_first_abbr;
+      } else {
+        mpp = &first_abbr;
+      }
+    } else {
+      if (local) {
+        mpp = &buf->b_maphash[hash];
+      } else {
+        mpp = &maphash[hash];
+      }
+    }
+    while (*mpp != NULL) {
+      mp = *mpp;
+      if (mp->m_mode & mode) {
+        mp->m_mode &= ~mode;
+        if (mp->m_mode == 0) {       // entry can be deleted
+          mapblock_free(mpp);
+          continue;
+        }
+        // May need to put this entry into another hash list.
+        new_hash = MAP_HASH(mp->m_mode, mp->m_keys[0]);
+        if (!abbr && new_hash != hash) {
+          *mpp = mp->m_next;
+          if (local) {
+            mp->m_next = buf->b_maphash[new_hash];
+            buf->b_maphash[new_hash] = mp;
+          } else {
+            mp->m_next = maphash[new_hash];
+            maphash[new_hash] = mp;
+          }
+          continue;                     // continue with *mpp
+        }
+      }
+      mpp = &(mp->m_next);
+    }
+  }
+}
+
+/// Check if a map exists that has given string in the rhs
+///
+/// Also checks mappings local to the current buffer.
+///
+/// @param[in]  str  String which mapping must have in the rhs. Termcap codes
+///                  are recognized in this argument.
+/// @param[in]  modechars  Mode(s) in which mappings are checked.
+/// @param[in]  abbr  true if checking abbreviations in place of mappings.
+///
+/// @return true if there is at least one mapping with given parameters.
+bool map_to_exists(const char *const str, const char *const modechars, const bool abbr)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_PURE
+{
+  int mode = 0;
+  int retval;
+
+  char_u *buf = NULL;
+  const char_u *const rhs = (char_u *)replace_termcodes(str, strlen(str),
+                                                        (char **)&buf, REPTERM_DO_LT,
+                                                        NULL, CPO_TO_CPO_FLAGS);
+
+#define MAPMODE(mode, modechars, chr, modeflags) \
+  do { \
+    if (strchr(modechars, chr) != NULL) { \
+      (mode) |= (modeflags); \
+    } \
+  } while (0)
+  MAPMODE(mode, modechars, 'n', MODE_NORMAL);
+  MAPMODE(mode, modechars, 'v', MODE_VISUAL | MODE_SELECT);
+  MAPMODE(mode, modechars, 'x', MODE_VISUAL);
+  MAPMODE(mode, modechars, 's', MODE_SELECT);
+  MAPMODE(mode, modechars, 'o', MODE_OP_PENDING);
+  MAPMODE(mode, modechars, 'i', MODE_INSERT);
+  MAPMODE(mode, modechars, 'l', MODE_LANGMAP);
+  MAPMODE(mode, modechars, 'c', MODE_CMDLINE);
+#undef MAPMODE
+
+  retval = map_to_exists_mode((char *)rhs, mode, abbr);
+  xfree(buf);
+
+  return retval;
+}
+
+/// Check if a map exists that has given string in the rhs
+///
+/// Also checks mappings local to the current buffer.
+///
+/// @param[in]  rhs  String which mapping must have in the rhs. Termcap codes
+///                  are recognized in this argument.
+/// @param[in]  mode  Mode(s) in which mappings are checked.
+/// @param[in]  abbr  true if checking abbreviations in place of mappings.
+///
+/// @return true if there is at least one mapping with given parameters.
+int map_to_exists_mode(const char *const rhs, const int mode, const bool abbr)
+{
+  mapblock_T *mp;
+  int hash;
+  bool exp_buffer = false;
+
+  // Do it twice: once for global maps and once for local maps.
+  for (;;) {
+    for (hash = 0; hash < 256; hash++) {
+      if (abbr) {
+        if (hash > 0) {  // There is only one abbr list.
+          break;
+        }
+        if (exp_buffer) {
+          mp = curbuf->b_first_abbr;
+        } else {
+          mp = first_abbr;
+        }
+      } else if (exp_buffer) {
+        mp = curbuf->b_maphash[hash];
+      } else {
+        mp = maphash[hash];
+      }
+      for (; mp; mp = mp->m_next) {
+        if ((mp->m_mode & mode) && strstr((char *)mp->m_str, rhs) != NULL) {
+          return true;
+        }
+      }
+    }
+    if (exp_buffer) {
+      break;
+    }
+    exp_buffer = true;
+  }
+
+  return false;
+}
+
+/// Used below when expanding mapping/abbreviation names.
+static int expand_mapmodes = 0;
+static bool expand_isabbrev = false;
+static bool expand_buffer = false;
+
+/// Translate an internal mapping/abbreviation representation into the
+/// corresponding external one recognized by :map/:abbrev commands.
+///
+/// This function is called when expanding mappings/abbreviations on the
+/// command-line.
+///
+/// It uses a growarray to build the translation string since the latter can be
+/// wider than the original description. The caller has to free the string
+/// afterwards.
+///
+/// @param cpo_flags  Value of various flags present in &cpo
+///
+/// @return  NULL when there is a problem.
+static char_u *translate_mapping(char_u *str, int cpo_flags)
+{
+  garray_T ga;
+  ga_init(&ga, 1, 40);
+
+  bool cpo_bslash = !(cpo_flags&FLAG_CPO_BSLASH);
+
+  for (; *str; str++) {
+    int c = *str;
+    if (c == K_SPECIAL && str[1] != NUL && str[2] != NUL) {
+      int modifiers = 0;
+      if (str[1] == KS_MODIFIER) {
+        str++;
+        modifiers = *++str;
+        c = *++str;
+      }
+
+      if (c == K_SPECIAL && str[1] != NUL && str[2] != NUL) {
+        c = TO_SPECIAL(str[1], str[2]);
+        if (c == K_ZERO) {
+          // display <Nul> as ^@
+          c = NUL;
+        }
+        str += 2;
+      }
+      if (IS_SPECIAL(c) || modifiers) {         // special key
+        ga_concat(&ga, (char *)get_special_key_name(c, modifiers));
+        continue;         // for (str)
+      }
+    }
+
+    if (c == ' ' || c == '\t' || c == Ctrl_J || c == Ctrl_V
+        || (c == '\\' && !cpo_bslash)) {
+      ga_append(&ga, cpo_bslash ? Ctrl_V : '\\');
+    }
+
+    if (c) {
+      ga_append(&ga, (char)c);
+    }
+  }
+  ga_append(&ga, NUL);
+  return (char_u *)(ga.ga_data);
+}
+
+/// Work out what to complete when doing command line completion of mapping
+/// or abbreviation names.
+///
+/// @param forceit  true if '!' given
+/// @param isabbrev  true if abbreviation
+/// @param isunmap  true if unmap/unabbrev command
+char_u *set_context_in_map_cmd(expand_T *xp, char_u *cmd, char_u *arg, bool forceit, bool isabbrev,
+                               bool isunmap, cmdidx_T cmdidx)
+{
+  if (forceit && cmdidx != CMD_map && cmdidx != CMD_unmap) {
+    xp->xp_context = EXPAND_NOTHING;
+  } else {
+    if (isunmap) {
+      expand_mapmodes = get_map_mode((char **)&cmd, forceit || isabbrev);
+    } else {
+      expand_mapmodes = MODE_INSERT | MODE_CMDLINE;
+      if (!isabbrev) {
+        expand_mapmodes |= MODE_VISUAL | MODE_SELECT | MODE_NORMAL | MODE_OP_PENDING;
+      }
+    }
+    expand_isabbrev = isabbrev;
+    xp->xp_context = EXPAND_MAPPINGS;
+    expand_buffer = false;
+    for (;;) {
+      if (STRNCMP(arg, "<buffer>", 8) == 0) {
+        expand_buffer = true;
+        arg = (char_u *)skipwhite((char *)arg + 8);
+        continue;
+      }
+      if (STRNCMP(arg, "<unique>", 8) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 8);
+        continue;
+      }
+      if (STRNCMP(arg, "<nowait>", 8) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 8);
+        continue;
+      }
+      if (STRNCMP(arg, "<silent>", 8) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 8);
+        continue;
+      }
+      if (STRNCMP(arg, "<special>", 9) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 9);
+        continue;
+      }
+      if (STRNCMP(arg, "<script>", 8) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 8);
+        continue;
+      }
+      if (STRNCMP(arg, "<expr>", 6) == 0) {
+        arg = (char_u *)skipwhite((char *)arg + 6);
+        continue;
+      }
+      break;
+    }
+    xp->xp_pattern = (char *)arg;
+  }
+
+  return NULL;
+}
+
+/// Find all mapping/abbreviation names that match regexp "regmatch".
+/// For command line expansion of ":[un]map" and ":[un]abbrev" in all modes.
+/// @return OK if matches found, FAIL otherwise.
+int ExpandMappings(regmatch_T *regmatch, int *num_file, char_u ***file)
+{
+  mapblock_T *mp;
+  int hash;
+  int count;
+  int round;
+  char_u *p;
+  int i;
+
+  *num_file = 0;                    // return values in case of FAIL
+  *file = NULL;
+
+  // round == 1: Count the matches.
+  // round == 2: Build the array to keep the matches.
+  for (round = 1; round <= 2; round++) {
+    count = 0;
+
+    for (i = 0; i < 7; i++) {
+      if (i == 0) {
+        p = (char_u *)"<silent>";
+      } else if (i == 1) {
+        p = (char_u *)"<unique>";
+      } else if (i == 2) {
+        p = (char_u *)"<script>";
+      } else if (i == 3) {
+        p = (char_u *)"<expr>";
+      } else if (i == 4 && !expand_buffer) {
+        p = (char_u *)"<buffer>";
+      } else if (i == 5) {
+        p = (char_u *)"<nowait>";
+      } else if (i == 6) {
+        p = (char_u *)"<special>";
+      } else {
+        continue;
+      }
+
+      if (vim_regexec(regmatch, (char *)p, (colnr_T)0)) {
+        if (round == 1) {
+          count++;
+        } else {
+          (*file)[count++] = vim_strsave(p);
+        }
+      }
+    }
+
+    for (hash = 0; hash < 256; hash++) {
+      if (expand_isabbrev) {
+        if (hash > 0) {    // only one abbrev list
+          break;           // for (hash)
+        }
+        mp = first_abbr;
+      } else if (expand_buffer) {
+        mp = curbuf->b_maphash[hash];
+      } else {
+        mp = maphash[hash];
+      }
+      for (; mp; mp = mp->m_next) {
+        if (mp->m_mode & expand_mapmodes) {
+          p = translate_mapping(mp->m_keys, CPO_TO_CPO_FLAGS);
+          if (p != NULL && vim_regexec(regmatch, (char *)p, (colnr_T)0)) {
+            if (round == 1) {
+              count++;
+            } else {
+              (*file)[count++] = p;
+              p = NULL;
+            }
+          }
+          xfree(p);
+        }
+      }       // for (mp)
+    }     // for (hash)
+
+    if (count == 0) {  // no match found
+      break;       // for (round)
+    }
+
+    if (round == 1) {
+      *file = (char_u **)xmalloc((size_t)count * sizeof(char_u *));
+    }
+  }   // for (round)
+
+  if (count > 1) {
+    char_u **ptr1;
+    char_u **ptr2;
+    char_u **ptr3;
+
+    // Sort the matches
+    sort_strings(*file, count);
+
+    // Remove multiple entries
+    ptr1 = *file;
+    ptr2 = ptr1 + 1;
+    ptr3 = ptr1 + count;
+
+    while (ptr2 < ptr3) {
+      if (STRCMP(*ptr1, *ptr2)) {
+        *++ptr1 = *ptr2++;
+      } else {
+        xfree(*ptr2++);
+        count--;
+      }
+    }
+  }
+
+  *num_file = count;
+  return count == 0 ? FAIL : OK;
+}
+
+// Check for an abbreviation.
+// Cursor is at ptr[col].
+// When inserting, mincol is where insert started.
+// For the command line, mincol is what is to be skipped over.
+// "c" is the character typed before check_abbr was called.  It may have
+// ABBR_OFF added to avoid prepending a CTRL-V to it.
+//
+// Historic vi practice: The last character of an abbreviation must be an id
+// character ([a-zA-Z0-9_]). The characters in front of it must be all id
+// characters or all non-id characters. This allows for abbr. "#i" to
+// "#include".
+//
+// Vim addition: Allow for abbreviations that end in a non-keyword character.
+// Then there must be white space before the abbr.
+//
+// Return true if there is an abbreviation, false if not.
+bool check_abbr(int c, char_u *ptr, int col, int mincol)
+{
+  int len;
+  int scol;                     // starting column of the abbr.
+  int j;
+  char_u *s;
+  char_u tb[MB_MAXBYTES + 4];
+  mapblock_T *mp;
+  mapblock_T *mp2;
+  int clen = 0;                 // length in characters
+  bool is_id = true;
+
+  if (typebuf.tb_no_abbr_cnt) {  // abbrev. are not recursive
+    return false;
+  }
+
+  // no remapping implies no abbreviation, except for CTRL-]
+  if (noremap_keys() && c != Ctrl_RSB) {
+    return false;
+  }
+
+  // Check for word before the cursor: If it ends in a keyword char all
+  // chars before it must be keyword chars or non-keyword chars, but not
+  // white space. If it ends in a non-keyword char we accept any characters
+  // before it except white space.
+  if (col == 0) {  // cannot be an abbr.
+    return false;
+  }
+
+  {
+    bool vim_abbr;
+    char_u *p = mb_prevptr(ptr, ptr + col);
+    if (!vim_iswordp(p)) {
+      vim_abbr = true;    // Vim added abbr.
+    } else {
+      vim_abbr = false;   // vi compatible abbr.
+      if (p > ptr) {
+        is_id = vim_iswordp(mb_prevptr(ptr, p));
+      }
+    }
+    clen = 1;
+    while (p > ptr + mincol) {
+      p = mb_prevptr(ptr, p);
+      if (ascii_isspace(*p) || (!vim_abbr && is_id != vim_iswordp(p))) {
+        p += utfc_ptr2len((char *)p);
+        break;
+      }
+      clen++;
+    }
+    scol = (int)(p - ptr);
+  }
+
+  if (scol < mincol) {
+    scol = mincol;
+  }
+  if (scol < col) {             // there is a word in front of the cursor
+    ptr += scol;
+    len = col - scol;
+    mp = curbuf->b_first_abbr;
+    mp2 = first_abbr;
+    if (mp == NULL) {
+      mp = mp2;
+      mp2 = NULL;
+    }
+    for (; mp;
+         mp->m_next == NULL ? (mp = mp2, mp2 = NULL) :
+         (mp = mp->m_next)) {
+      int qlen = mp->m_keylen;
+      char_u *q = mp->m_keys;
+      int match;
+
+      if (strchr((const char *)mp->m_keys, K_SPECIAL) != NULL) {
+        // Might have K_SPECIAL escaped mp->m_keys.
+        q = vim_strsave(mp->m_keys);
+        vim_unescape_ks(q);
+        qlen = (int)STRLEN(q);
+      }
+      // find entries with right mode and keys
+      match = (mp->m_mode & State)
+              && qlen == len
+              && !STRNCMP(q, ptr, (size_t)len);
+      if (q != mp->m_keys) {
+        xfree(q);
+      }
+      if (match) {
+        break;
+      }
+    }
+    if (mp != NULL) {
+      // Found a match:
+      // Insert the rest of the abbreviation in typebuf.tb_buf[].
+      // This goes from end to start.
+      //
+      // Characters 0x000 - 0x100: normal chars, may need CTRL-V,
+      // except K_SPECIAL: Becomes K_SPECIAL KS_SPECIAL KE_FILLER
+      // Characters where IS_SPECIAL() == true: key codes, need
+      // K_SPECIAL. Other characters (with ABBR_OFF): don't use CTRL-V.
+      //
+      // Character CTRL-] is treated specially - it completes the
+      // abbreviation, but is not inserted into the input stream.
+      j = 0;
+      if (c != Ctrl_RSB) {
+        // special key code, split up
+        if (IS_SPECIAL(c) || c == K_SPECIAL) {
+          tb[j++] = K_SPECIAL;
+          tb[j++] = (char_u)K_SECOND(c);
+          tb[j++] = (char_u)K_THIRD(c);
+        } else {
+          if (c < ABBR_OFF && (c < ' ' || c > '~')) {
+            tb[j++] = Ctrl_V;                   // special char needs CTRL-V
+          }
+          // if ABBR_OFF has been added, remove it here.
+          if (c >= ABBR_OFF) {
+            c -= ABBR_OFF;
+          }
+          int newlen = utf_char2bytes(c, (char *)tb + j);
+          tb[j + newlen] = NUL;
+          // Need to escape K_SPECIAL.
+          char_u *escaped = (char_u *)vim_strsave_escape_ks((char *)tb + j);
+          if (escaped != NULL) {
+            newlen = (int)STRLEN(escaped);
+            memmove(tb + j, escaped, (size_t)newlen);
+            j += newlen;
+            xfree(escaped);
+          }
+        }
+        tb[j] = NUL;
+        // insert the last typed char
+        (void)ins_typebuf((char *)tb, 1, 0, true, mp->m_silent);
+      }
+      if (mp->m_expr) {
+        s = eval_map_expr(mp, c);
+      } else {
+        s = mp->m_str;
+      }
+      if (s != NULL) {
+        // insert the to string
+        (void)ins_typebuf((char *)s, mp->m_noremap, 0, true, mp->m_silent);
+        // no abbrev. for these chars
+        typebuf.tb_no_abbr_cnt += (int)STRLEN(s) + j + 1;
+        if (mp->m_expr) {
+          xfree(s);
+        }
+      }
+
+      tb[0] = Ctrl_H;
+      tb[1] = NUL;
+      len = clen;  // Delete characters instead of bytes
+      while (len-- > 0) {  // delete the from string
+        (void)ins_typebuf((char *)tb, 1, 0, true, mp->m_silent);
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
+/// Evaluate the RHS of a mapping or abbreviations and take care of escaping
+/// special characters.
+///
+/// @param c  NUL or typed character for abbreviation
+char_u *eval_map_expr(mapblock_T *mp, int c)
+{
+  char_u *res;
+  char_u *p = NULL;
+  char_u *expr = NULL;
+  pos_T save_cursor;
+  int save_msg_col;
+  int save_msg_row;
+
+  // Remove escaping of K_SPECIAL, because "str" is in a format to be used as
+  // typeahead.
+  if (mp->m_luaref == LUA_NOREF) {
+    expr = vim_strsave(mp->m_str);
+    vim_unescape_ks(expr);
+  }
+
+  // Forbid changing text or using ":normal" to avoid most of the bad side
+  // effects.  Also restore the cursor position.
+  textlock++;
+  ex_normal_lock++;
+  set_vim_var_char(c);    // set v:char to the typed character
+  save_cursor = curwin->w_cursor;
+  save_msg_col = msg_col;
+  save_msg_row = msg_row;
+  if (mp->m_luaref != LUA_NOREF) {
+    Error err = ERROR_INIT;
+    Array args = ARRAY_DICT_INIT;
+    Object ret = nlua_call_ref(mp->m_luaref, NULL, args, true, &err);
+    if (ret.type == kObjectTypeString) {
+      p = (char_u *)xstrndup(ret.data.string.data, ret.data.string.size);
+    }
+    api_free_object(ret);
+    if (err.type != kErrorTypeNone) {
+      semsg_multiline("E5108: %s", err.msg);
+      api_clear_error(&err);
+    }
+  } else {
+    p = (char_u *)eval_to_string((char *)expr, NULL, false);
+    xfree(expr);
+  }
+  textlock--;
+  ex_normal_lock--;
+  curwin->w_cursor = save_cursor;
+  msg_col = save_msg_col;
+  msg_row = save_msg_row;
+
+  if (p == NULL) {
+    return NULL;
+  }
+  // Escape K_SPECIAL in the result to be able to use the string as typeahead.
+  res = (char_u *)vim_strsave_escape_ks((char *)p);
+  xfree(p);
+
+  return res;
+}
+
+/// Write map commands for the current mappings to an .exrc file.
+/// Return FAIL on error, OK otherwise.
+///
+/// @param buf  buffer for local mappings or NULL
+int makemap(FILE *fd, buf_T *buf)
+{
+  mapblock_T *mp;
+  char_u c1, c2, c3;
+  char_u *p;
+  char *cmd;
+  int abbr;
+  int hash;
+  bool did_cpo = false;
+
+  // Do the loop twice: Once for mappings, once for abbreviations.
+  // Then loop over all map hash lists.
+  for (abbr = 0; abbr < 2; abbr++) {
+    for (hash = 0; hash < 256; hash++) {
+      if (abbr) {
+        if (hash > 0) {                 // there is only one abbr list
+          break;
+        }
+        if (buf != NULL) {
+          mp = buf->b_first_abbr;
+        } else {
+          mp = first_abbr;
+        }
+      } else {
+        if (buf != NULL) {
+          mp = buf->b_maphash[hash];
+        } else {
+          mp = maphash[hash];
+        }
+      }
+
+      for (; mp; mp = mp->m_next) {
+        // skip script-local mappings
+        if (mp->m_noremap == REMAP_SCRIPT) {
+          continue;
+        }
+
+        // skip lua mappings and mappings that contain a <SNR> (script-local thing),
+        // they probably don't work when loaded again
+        if (mp->m_luaref != LUA_NOREF) {
+          continue;
+        }
+        for (p = mp->m_str; *p != NUL; p++) {
+          if (p[0] == K_SPECIAL && p[1] == KS_EXTRA
+              && p[2] == KE_SNR) {
+            break;
+          }
+        }
+        if (*p != NUL) {
+          continue;
+        }
+
+        // It's possible to create a mapping and then ":unmap" certain
+        // modes.  We recreate this here by mapping the individual
+        // modes, which requires up to three of them.
+        c1 = NUL;
+        c2 = NUL;
+        c3 = NUL;
+        if (abbr) {
+          cmd = "abbr";
+        } else {
+          cmd = "map";
+        }
+        switch (mp->m_mode) {
+        case MODE_NORMAL | MODE_VISUAL | MODE_SELECT | MODE_OP_PENDING:
+          break;
+        case MODE_NORMAL:
+          c1 = 'n';
+          break;
+        case MODE_VISUAL:
+          c1 = 'x';
+          break;
+        case MODE_SELECT:
+          c1 = 's';
+          break;
+        case MODE_OP_PENDING:
+          c1 = 'o';
+          break;
+        case MODE_NORMAL | MODE_VISUAL:
+          c1 = 'n';
+          c2 = 'x';
+          break;
+        case MODE_NORMAL | MODE_SELECT:
+          c1 = 'n';
+          c2 = 's';
+          break;
+        case MODE_NORMAL | MODE_OP_PENDING:
+          c1 = 'n';
+          c2 = 'o';
+          break;
+        case MODE_VISUAL | MODE_SELECT:
+          c1 = 'v';
+          break;
+        case MODE_VISUAL | MODE_OP_PENDING:
+          c1 = 'x';
+          c2 = 'o';
+          break;
+        case MODE_SELECT | MODE_OP_PENDING:
+          c1 = 's';
+          c2 = 'o';
+          break;
+        case MODE_NORMAL | MODE_VISUAL | MODE_SELECT:
+          c1 = 'n';
+          c2 = 'v';
+          break;
+        case MODE_NORMAL | MODE_VISUAL | MODE_OP_PENDING:
+          c1 = 'n';
+          c2 = 'x';
+          c3 = 'o';
+          break;
+        case MODE_NORMAL | MODE_SELECT | MODE_OP_PENDING:
+          c1 = 'n';
+          c2 = 's';
+          c3 = 'o';
+          break;
+        case MODE_VISUAL | MODE_SELECT | MODE_OP_PENDING:
+          c1 = 'v';
+          c2 = 'o';
+          break;
+        case MODE_CMDLINE | MODE_INSERT:
+          if (!abbr) {
+            cmd = "map!";
+          }
+          break;
+        case MODE_CMDLINE:
+          c1 = 'c';
+          break;
+        case MODE_INSERT:
+          c1 = 'i';
+          break;
+        case MODE_LANGMAP:
+          c1 = 'l';
+          break;
+        case MODE_TERMINAL:
+          c1 = 't';
+          break;
+        default:
+          iemsg(_("E228: makemap: Illegal mode"));
+          return FAIL;
+        }
+        do {
+          // do this twice if c2 is set, 3 times with c3 */
+          // When outputting <> form, need to make sure that 'cpo'
+          // is set to the Vim default.
+          if (!did_cpo) {
+            if (*mp->m_str == NUL) {  // Will use <Nop>.
+              did_cpo = true;
+            } else {
+              const char specials[] = { (char)(uint8_t)K_SPECIAL, NL, NUL };
+              if (strpbrk((const char *)mp->m_str, specials) != NULL
+                  || strpbrk((const char *)mp->m_keys, specials) != NULL) {
+                did_cpo = true;
+              }
+            }
+            if (did_cpo) {
+              if (fprintf(fd, "let s:cpo_save=&cpo") < 0
+                  || put_eol(fd) < 0
+                  || fprintf(fd, "set cpo&vim") < 0
+                  || put_eol(fd) < 0) {
+                return FAIL;
+              }
+            }
+          }
+          if (c1 && putc(c1, fd) < 0) {
+            return FAIL;
+          }
+          if (mp->m_noremap != REMAP_YES && fprintf(fd, "nore") < 0) {
+            return FAIL;
+          }
+          if (fputs(cmd, fd) < 0) {
+            return FAIL;
+          }
+          if (buf != NULL && fputs(" <buffer>", fd) < 0) {
+            return FAIL;
+          }
+          if (mp->m_nowait && fputs(" <nowait>", fd) < 0) {
+            return FAIL;
+          }
+          if (mp->m_silent && fputs(" <silent>", fd) < 0) {
+            return FAIL;
+          }
+          if (mp->m_expr && fputs(" <expr>", fd) < 0) {
+            return FAIL;
+          }
+
+          if (putc(' ', fd) < 0
+              || put_escstr(fd, mp->m_keys, 0) == FAIL
+              || putc(' ', fd) < 0
+              || put_escstr(fd, mp->m_str, 1) == FAIL
+              || put_eol(fd) < 0) {
+            return FAIL;
+          }
+          c1 = c2;
+          c2 = c3;
+          c3 = NUL;
+        } while (c1 != NUL);
+      }
+    }
+  }
+  if (did_cpo) {
+    if (fprintf(fd, "let &cpo=s:cpo_save") < 0
+        || put_eol(fd) < 0
+        || fprintf(fd, "unlet s:cpo_save") < 0
+        || put_eol(fd) < 0) {
+      return FAIL;
+    }
+  }
+  return OK;
+}
+
+// write escape string to file
+// "what": 0 for :map lhs, 1 for :map rhs, 2 for :set
+//
+// return FAIL for failure, OK otherwise
+int put_escstr(FILE *fd, char_u *strstart, int what)
+{
+  char_u *str = strstart;
+  int c;
+
+  // :map xx <Nop>
+  if (*str == NUL && what == 1) {
+    if (fprintf(fd, "<Nop>") < 0) {
+      return FAIL;
+    }
+    return OK;
+  }
+
+  for (; *str != NUL; str++) {
+    // Check for a multi-byte character, which may contain escaped
+    // K_SPECIAL bytes.
+    const char *p = mb_unescape((const char **)&str);
+    if (p != NULL) {
+      while (*p != NUL) {
+        if (fputc(*p++, fd) < 0) {
+          return FAIL;
+        }
+      }
+      str--;
+      continue;
+    }
+
+    c = *str;
+    // Special key codes have to be translated to be able to make sense
+    // when they are read back.
+    if (c == K_SPECIAL && what != 2) {
+      int modifiers = 0;
+      if (str[1] == KS_MODIFIER) {
+        modifiers = str[2];
+        str += 3;
+        c = *str;
+      }
+      if (c == K_SPECIAL) {
+        c = TO_SPECIAL(str[1], str[2]);
+        str += 2;
+      }
+      if (IS_SPECIAL(c) || modifiers) {         // special key
+        if (fputs((char *)get_special_key_name(c, modifiers), fd) < 0) {
+          return FAIL;
+        }
+        continue;
+      }
+    }
+
+    // A '\n' in a map command should be written as <NL>.
+    // A '\n' in a set command should be written as \^V^J.
+    if (c == NL) {
+      if (what == 2) {
+        if (fprintf(fd, "\\\026\n") < 0) {
+          return FAIL;
+        }
+      } else {
+        if (fprintf(fd, "<NL>") < 0) {
+          return FAIL;
+        }
+      }
+      continue;
+    }
+
+    // Some characters have to be escaped with CTRL-V to
+    // prevent them from misinterpreted in DoOneCmd().
+    // A space, Tab and '"' has to be escaped with a backslash to
+    // prevent it to be misinterpreted in do_set().
+    // A space has to be escaped with a CTRL-V when it's at the start of a
+    // ":map" rhs.
+    // A '<' has to be escaped with a CTRL-V to prevent it being
+    // interpreted as the start of a special key name.
+    // A space in the lhs of a :map needs a CTRL-V.
+    if (what == 2 && (ascii_iswhite(c) || c == '"' || c == '\\')) {
+      if (putc('\\', fd) < 0) {
+        return FAIL;
+      }
+    } else if (c < ' ' || c > '~' || c == '|'
+               || (what == 0 && c == ' ')
+               || (what == 1 && str == strstart && c == ' ')
+               || (what != 2 && c == '<')) {
+      if (putc(Ctrl_V, fd) < 0) {
+        return FAIL;
+      }
+    }
+    if (putc(c, fd) < 0) {
+      return FAIL;
+    }
+  }
+  return OK;
+}
+
+/// Check the string "keys" against the lhs of all mappings.
+/// Return pointer to rhs of mapping (mapblock->m_str).
+/// NULL when no mapping found.
+///
+/// @param exact  require exact match
+/// @param ign_mod  ignore preceding modifier
+/// @param abbr  do abbreviations
+/// @param mp_ptr  return: pointer to mapblock or NULL
+/// @param local_ptr  return: buffer-local mapping or NULL
+char_u *check_map(char_u *keys, int mode, int exact, int ign_mod, int abbr, mapblock_T **mp_ptr,
+                  int *local_ptr, int *rhs_lua)
+{
+  int len, minlen;
+  mapblock_T *mp;
+  *rhs_lua = LUA_NOREF;
+
+  len = (int)STRLEN(keys);
+  for (int local = 1; local >= 0; local--) {
+    // loop over all hash lists
+    for (int hash = 0; hash < 256; hash++) {
+      if (abbr) {
+        if (hash > 0) {                 // there is only one list.
+          break;
+        }
+        if (local) {
+          mp = curbuf->b_first_abbr;
+        } else {
+          mp = first_abbr;
+        }
+      } else if (local) {
+        mp = curbuf->b_maphash[hash];
+      } else {
+        mp = maphash[hash];
+      }
+      for (; mp != NULL; mp = mp->m_next) {
+        // skip entries with wrong mode, wrong length and not matching ones
+        if ((mp->m_mode & mode) && (!exact || mp->m_keylen == len)) {
+          char_u *s = mp->m_keys;
+          int keylen = mp->m_keylen;
+          if (ign_mod && keylen >= 3
+              && s[0] == K_SPECIAL && s[1] == KS_MODIFIER) {
+            s += 3;
+            keylen -= 3;
+          }
+          minlen = keylen < len ? keylen : len;
+          if (STRNCMP(s, keys, minlen) == 0) {
+            if (mp_ptr != NULL) {
+              *mp_ptr = mp;
+            }
+            if (local_ptr != NULL) {
+              *local_ptr = local;
+            }
+            *rhs_lua = mp->m_luaref;
+            return mp->m_luaref == LUA_NOREF ? mp->m_str : NULL;
+          }
+        }
+      }
+    }
+  }
+
+  return NULL;
+}
+
+/// "hasmapto()" function
+void f_hasmapto(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  const char *mode;
+  const char *const name = tv_get_string(&argvars[0]);
+  bool abbr = false;
+  char buf[NUMBUFLEN];
+  if (argvars[1].v_type == VAR_UNKNOWN) {
+    mode = "nvo";
+  } else {
+    mode = tv_get_string_buf(&argvars[1], buf);
+    if (argvars[2].v_type != VAR_UNKNOWN) {
+      abbr = tv_get_number(&argvars[2]);
+    }
+  }
+
+  if (map_to_exists(name, mode, abbr)) {
+    rettv->vval.v_number = true;
+  } else {
+    rettv->vval.v_number = false;
+  }
+}
+
+/// Fill a dictionary with all applicable maparg() like dictionaries
+///
+/// @param dict          The dictionary to be filled
+/// @param mp            The maphash that contains the mapping information
+/// @param buffer_value  The "buffer" value
+/// @param compatible    True for compatible with old maparg() dict
+static void mapblock_fill_dict(dict_T *const dict, const mapblock_T *const mp, long buffer_value,
+                               bool compatible)
+  FUNC_ATTR_NONNULL_ALL
+{
+  char *const lhs = str2special_save((const char *)mp->m_keys,
+                                     compatible, !compatible);
+  char *const mapmode = map_mode_to_chars(mp->m_mode);
+  varnumber_T noremap_value;
+
+  if (compatible) {
+    // Keep old compatible behavior
+    // This is unable to determine whether a mapping is a <script> mapping
+    noremap_value = !!mp->m_noremap;
+  } else {
+    // Distinguish between <script> mapping
+    // If it's not a <script> mapping, check if it's a noremap
+    noremap_value = mp->m_noremap == REMAP_SCRIPT ? 2 : !!mp->m_noremap;
+  }
+
+  if (mp->m_luaref != LUA_NOREF) {
+    tv_dict_add_nr(dict, S_LEN("callback"), mp->m_luaref);
+  } else {
+    if (compatible) {
+      tv_dict_add_str(dict, S_LEN("rhs"), (const char *)mp->m_orig_str);
+    } else {
+      tv_dict_add_allocated_str(dict, S_LEN("rhs"),
+                                str2special_save((const char *)mp->m_str, false,
+                                                 true));
+    }
+  }
+  if (mp->m_desc != NULL) {
+    tv_dict_add_allocated_str(dict, S_LEN("desc"), xstrdup(mp->m_desc));
+  }
+  tv_dict_add_allocated_str(dict, S_LEN("lhs"), lhs);
+  tv_dict_add_nr(dict, S_LEN("noremap"), noremap_value);
+  tv_dict_add_nr(dict, S_LEN("script"), mp->m_noremap == REMAP_SCRIPT ? 1 : 0);
+  tv_dict_add_nr(dict, S_LEN("expr"),  mp->m_expr ? 1 : 0);
+  tv_dict_add_nr(dict, S_LEN("silent"), mp->m_silent ? 1 : 0);
+  tv_dict_add_nr(dict, S_LEN("sid"), (varnumber_T)mp->m_script_ctx.sc_sid);
+  tv_dict_add_nr(dict, S_LEN("lnum"), (varnumber_T)mp->m_script_ctx.sc_lnum);
+  tv_dict_add_nr(dict, S_LEN("buffer"), (varnumber_T)buffer_value);
+  tv_dict_add_nr(dict, S_LEN("nowait"), mp->m_nowait ? 1 : 0);
+  tv_dict_add_allocated_str(dict, S_LEN("mode"), mapmode);
+}
+
+static void get_maparg(typval_T *argvars, typval_T *rettv, int exact)
+{
+  char *keys_buf = NULL;
+  char_u *alt_keys_buf = NULL;
+  bool did_simplify = false;
+  char_u *rhs;
+  LuaRef rhs_lua;
+  int mode;
+  bool abbr = false;
+  bool get_dict = false;
+  mapblock_T *mp;
+  int buffer_local;
+  int flags = REPTERM_FROM_PART | REPTERM_DO_LT;
+
+  // Return empty string for failure.
+  rettv->v_type = VAR_STRING;
+  rettv->vval.v_string = NULL;
+
+  char *keys = (char *)tv_get_string(&argvars[0]);
+  if (*keys == NUL) {
+    return;
+  }
+
+  char buf[NUMBUFLEN];
+  const char *which;
+  if (argvars[1].v_type != VAR_UNKNOWN) {
+    which = tv_get_string_buf_chk(&argvars[1], buf);
+    if (argvars[2].v_type != VAR_UNKNOWN) {
+      abbr = (bool)tv_get_number(&argvars[2]);
+      if (argvars[3].v_type != VAR_UNKNOWN) {
+        get_dict = (bool)tv_get_number(&argvars[3]);
+      }
+    }
+  } else {
+    which = "";
+  }
+  if (which == NULL) {
+    return;
+  }
+
+  mode = get_map_mode((char **)&which, 0);
+
+  char_u *keys_simplified
+    = (char_u *)replace_termcodes(keys,
+                                  STRLEN(keys), &keys_buf, flags, &did_simplify,
+                                  CPO_TO_CPO_FLAGS);
+  rhs = check_map(keys_simplified, mode, exact, false, abbr, &mp, &buffer_local, &rhs_lua);
+  if (did_simplify) {
+    // When the lhs is being simplified the not-simplified keys are
+    // preferred for printing, like in do_map().
+    (void)replace_termcodes(keys,
+                            STRLEN(keys),
+                            (char **)&alt_keys_buf, flags | REPTERM_NO_SIMPLIFY, NULL,
+                            CPO_TO_CPO_FLAGS);
+    rhs = check_map(alt_keys_buf, mode, exact, false, abbr, &mp, &buffer_local, &rhs_lua);
+  }
+
+  if (!get_dict) {
+    // Return a string.
+    if (rhs != NULL) {
+      if (*rhs == NUL) {
+        rettv->vval.v_string = xstrdup("<Nop>");
+      } else {
+        rettv->vval.v_string = str2special_save((char *)rhs, false, false);
+      }
+    } else if (rhs_lua != LUA_NOREF) {
+      size_t msglen = 100;
+      char *msg = (char *)xmalloc(msglen);
+      snprintf(msg, msglen, "<Lua function %d>", mp->m_luaref);
+      rettv->vval.v_string = msg;
+    }
+  } else {
+    tv_dict_alloc_ret(rettv);
+    if (mp != NULL && (rhs != NULL || rhs_lua != LUA_NOREF)) {
+      // Return a dictionary.
+      mapblock_fill_dict(rettv->vval.v_dict, mp, buffer_local, true);
+    }
+  }
+
+  xfree(keys_buf);
+  xfree(alt_keys_buf);
+}
+
+/// "maparg()" function
+void f_maparg(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  get_maparg(argvars, rettv, true);
+}
+
+/// "mapcheck()" function
+void f_mapcheck(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+  get_maparg(argvars, rettv, false);
+}
+
+/// Add a mapping. Unlike @ref do_map this copies the string arguments, so
+/// static or read-only strings can be used.
+///
+/// @param lhs  C-string containing the lhs of the mapping
+/// @param rhs  C-string containing the rhs of the mapping
+/// @param mode  Bitflags representing the mode in which to set the mapping.
+///              See @ref get_map_mode.
+/// @param buffer  If true, make a buffer-local mapping for curbuf
+void add_map(char *lhs, char *rhs, int mode, bool buffer)
+{
+  MapArguments args = { 0 };
+  set_maparg_lhs_rhs(lhs, strlen(lhs), rhs, strlen(rhs), LUA_NOREF, 0, &args);
+  args.buffer = buffer;
+
+  buf_do_map(2, &args, mode, false, curbuf);
+  xfree(args.rhs);
+  xfree(args.orig_rhs);
+}
+
+/// Any character has an equivalent 'langmap' character.  This is used for
+/// keyboards that have a special language mode that sends characters above
+/// 128 (although other characters can be translated too).  The "to" field is a
+/// Vim command character.  This avoids having to switch the keyboard back to
+/// ASCII mode when leaving Insert mode.
+///
+/// langmap_mapchar[] maps any of 256 chars to an ASCII char used for Vim
+/// commands.
+/// langmap_mapga.ga_data is a sorted table of langmap_entry_T.
+/// This does the same as langmap_mapchar[] for characters >= 256.
+///
+/// With multi-byte support use growarray for 'langmap' chars >= 256
+typedef struct {
+  int from;
+  int to;
+} langmap_entry_T;
+
+static garray_T langmap_mapga = GA_EMPTY_INIT_VALUE;
+
+/// Search for an entry in "langmap_mapga" for "from".  If found set the "to"
+/// field.  If not found insert a new entry at the appropriate location.
+static void langmap_set_entry(int from, int to)
+{
+  langmap_entry_T *entries = (langmap_entry_T *)(langmap_mapga.ga_data);
+  unsigned int a = 0;
+  assert(langmap_mapga.ga_len >= 0);
+  unsigned int b = (unsigned int)langmap_mapga.ga_len;
+
+  // Do a binary search for an existing entry.
+  while (a != b) {
+    unsigned int i = (a + b) / 2;
+    int d = entries[i].from - from;
+
+    if (d == 0) {
+      entries[i].to = to;
+      return;
+    }
+    if (d < 0) {
+      a = i + 1;
+    } else {
+      b = i;
+    }
+  }
+
+  ga_grow(&langmap_mapga, 1);
+
+  // insert new entry at position "a"
+  entries = (langmap_entry_T *)(langmap_mapga.ga_data) + a;
+  memmove(entries + 1, entries,
+          ((unsigned int)langmap_mapga.ga_len - a) * sizeof(langmap_entry_T));
+  langmap_mapga.ga_len++;
+  entries[0].from = from;
+  entries[0].to = to;
+}
+
+/// Apply 'langmap' to multi-byte character "c" and return the result.
+int langmap_adjust_mb(int c)
+{
+  langmap_entry_T *entries = (langmap_entry_T *)(langmap_mapga.ga_data);
+  int a = 0;
+  int b = langmap_mapga.ga_len;
+
+  while (a != b) {
+    int i = (a + b) / 2;
+    int d = entries[i].from - c;
+
+    if (d == 0) {
+      return entries[i].to;        // found matching entry
+    }
+    if (d < 0) {
+      a = i + 1;
+    } else {
+      b = i;
+    }
+  }
+  return c;    // no entry found, return "c" unmodified
+}
+
+void langmap_init(void)
+{
+  for (int i = 0; i < 256; i++) {
+    langmap_mapchar[i] = (char_u)i;      // we init with a one-to-one map
+  }
+  ga_init(&langmap_mapga, sizeof(langmap_entry_T), 8);
+}
+
+/// Called when langmap option is set; the language map can be
+/// changed at any time!
+void langmap_set(void)
+{
+  char_u *p;
+  char_u *p2;
+  int from, to;
+
+  ga_clear(&langmap_mapga);                 // clear the previous map first
+  langmap_init();                           // back to one-to-one map
+
+  for (p = p_langmap; p[0] != NUL;) {
+    for (p2 = p; p2[0] != NUL && p2[0] != ',' && p2[0] != ';';
+         MB_PTR_ADV(p2)) {
+      if (p2[0] == '\\' && p2[1] != NUL) {
+        p2++;
+      }
+    }
+    if (p2[0] == ';') {
+      p2++;                 // abcd;ABCD form, p2 points to A
+    } else {
+      p2 = NULL;            // aAbBcCdD form, p2 is NULL
+    }
+    while (p[0]) {
+      if (p[0] == ',') {
+        p++;
+        break;
+      }
+      if (p[0] == '\\' && p[1] != NUL) {
+        p++;
+      }
+      from = utf_ptr2char((char *)p);
+      to = NUL;
+      if (p2 == NULL) {
+        MB_PTR_ADV(p);
+        if (p[0] != ',') {
+          if (p[0] == '\\') {
+            p++;
+          }
+          to = utf_ptr2char((char *)p);
+        }
+      } else {
+        if (p2[0] != ',') {
+          if (p2[0] == '\\') {
+            p2++;
+          }
+          to = utf_ptr2char((char *)p2);
+        }
+      }
+      if (to == NUL) {
+        semsg(_("E357: 'langmap': Matching character missing for %s"),
+              transchar(from));
+        return;
+      }
+
+      if (from >= 256) {
+        langmap_set_entry(from, to);
+      } else {
+        assert(to <= UCHAR_MAX);
+        langmap_mapchar[from & 255] = (char_u)to;
+      }
+
+      // Advance to next pair
+      MB_PTR_ADV(p);
+      if (p2 != NULL) {
+        MB_PTR_ADV(p2);
+        if (*p == ';') {
+          p = p2;
+          if (p[0] != NUL) {
+            if (p[0] != ',') {
+              semsg(_("E358: 'langmap': Extra characters after semicolon: %s"),
+                    p);
+              return;
+            }
+            p++;
+          }
+          break;
+        }
+      }
+    }
+  }
+}
+
+static void do_exmap(exarg_T *eap, int isabbrev)
+{
+  int mode;
+  char *cmdp = eap->cmd;
+  mode = get_map_mode(&cmdp, eap->forceit || isabbrev);
+
+  switch (do_map((*cmdp == 'n') ? 2 : (*cmdp == 'u'),
+                 (char_u *)eap->arg, mode, isabbrev)) {
+  case 1:
+    emsg(_(e_invarg));
+    break;
+  case 2:
+    emsg(isabbrev ? _(e_noabbr) : _(e_nomap));
+    break;
+  }
+}
+
+/// ":abbreviate" and friends.
+void ex_abbreviate(exarg_T *eap)
+{
+  do_exmap(eap, true);          // almost the same as mapping
+}
+
+/// ":map" and friends.
+void ex_map(exarg_T *eap)
+{
+  // If we are sourcing .exrc or .vimrc in current directory we
+  // print the mappings for security reasons.
+  if (secure) {
+    secure = 2;
+    msg_outtrans(eap->cmd);
+    msg_putchar('\n');
+  }
+  do_exmap(eap, false);
+}
+
+/// ":unmap" and friends.
+void ex_unmap(exarg_T *eap)
+{
+  do_exmap(eap, false);
+}
+
+/// ":mapclear" and friends.
+void ex_mapclear(exarg_T *eap)
+{
+  do_mapclear((char_u *)eap->cmd, (char_u *)eap->arg, eap->forceit, false);
+}
+
+/// ":abclear" and friends.
+void ex_abclear(exarg_T *eap)
+{
+  do_mapclear((char_u *)eap->cmd, (char_u *)eap->arg, true, true);
+}
+
+/// Set, tweak, or remove a mapping in a mode. Acts as the implementation for
+/// functions like @ref nvim_buf_set_keymap.
+///
+/// Arguments are handled like @ref nvim_set_keymap unless noted.
+/// @param  buffer    Buffer handle for a specific buffer, or 0 for the current
+///                   buffer, or -1 to signify global behavior ("all buffers")
+/// @param  is_unmap  When true, removes the mapping that matches {lhs}.
+void modify_keymap(uint64_t channel_id, Buffer buffer, bool is_unmap, String mode, String lhs,
+                   String rhs, Dict(keymap) *opts, Error *err)
+{
+  LuaRef lua_funcref = LUA_NOREF;
+  bool global = (buffer == -1);
+  if (global) {
+    buffer = 0;
+  }
+  buf_T *target_buf = find_buffer_by_handle(buffer, err);
+
+  if (!target_buf) {
+    return;
+  }
+
+  const sctx_T save_current_sctx = api_set_sctx(channel_id);
+
+  if (opts != NULL && opts->callback.type == kObjectTypeLuaRef) {
+    lua_funcref = opts->callback.data.luaref;
+    opts->callback.data.luaref = LUA_NOREF;
+  }
+  MapArguments parsed_args = MAP_ARGUMENTS_INIT;
+  if (opts) {
+#define KEY_TO_BOOL(name) \
+  parsed_args.name = api_object_to_bool(opts->name, #name, false, err); \
+  if (ERROR_SET(err)) { \
+    goto fail_and_free; \
+  }
+
+    KEY_TO_BOOL(nowait);
+    KEY_TO_BOOL(noremap);
+    KEY_TO_BOOL(silent);
+    KEY_TO_BOOL(script);
+    KEY_TO_BOOL(expr);
+    KEY_TO_BOOL(unique);
+#undef KEY_TO_BOOL
+  }
+  parsed_args.buffer = !global;
+
+  if (!set_maparg_lhs_rhs(lhs.data, lhs.size,
+                          rhs.data, rhs.size, lua_funcref,
+                          CPO_TO_CPO_FLAGS, &parsed_args)) {
+    api_set_error(err, kErrorTypeValidation,  "LHS exceeds maximum map length: %s", lhs.data);
+    goto fail_and_free;
+  }
+
+  if (opts != NULL && opts->desc.type == kObjectTypeString) {
+    parsed_args.desc = string_to_cstr(opts->desc.data.string);
+  } else {
+    parsed_args.desc = NULL;
+  }
+  if (parsed_args.lhs_len > MAXMAPLEN || parsed_args.alt_lhs_len > MAXMAPLEN) {
+    api_set_error(err, kErrorTypeValidation,  "LHS exceeds maximum map length: %s", lhs.data);
+    goto fail_and_free;
+  }
+
+  if (mode.size > 1) {
+    api_set_error(err, kErrorTypeValidation, "Shortname is too long: %s", mode.data);
+    goto fail_and_free;
+  }
+  int mode_val;  // integer value of the mapping mode, to be passed to do_map()
+  char *p = (mode.size) ? mode.data : "m";
+  if (STRNCMP(p, "!", 2) == 0) {
+    mode_val = get_map_mode(&p, true);  // mapmode-ic
+  } else {
+    mode_val = get_map_mode(&p, false);
+    if (mode_val == (MODE_VISUAL | MODE_SELECT | MODE_NORMAL | MODE_OP_PENDING) && mode.size > 0) {
+      // get_map_mode() treats unrecognized mode shortnames as ":map".
+      // This is an error unless the given shortname was empty string "".
+      api_set_error(err, kErrorTypeValidation, "Invalid mode shortname: \"%s\"", p);
+      goto fail_and_free;
+    }
+  }
+
+  if (parsed_args.lhs_len == 0) {
+    api_set_error(err, kErrorTypeValidation, "Invalid (empty) LHS");
+    goto fail_and_free;
+  }
+
+  bool is_noremap = parsed_args.noremap;
+  assert(!(is_unmap && is_noremap));
+
+  if (!is_unmap && lua_funcref == LUA_NOREF
+      && (parsed_args.rhs_len == 0 && !parsed_args.rhs_is_noop)) {
+    if (rhs.size == 0) {  // assume that the user wants RHS to be a <Nop>
+      parsed_args.rhs_is_noop = true;
+    } else {
+      abort();  // should never happen
+    }
+  } else if (is_unmap && (parsed_args.rhs_len || parsed_args.rhs_lua != LUA_NOREF)) {
+    if (parsed_args.rhs_len) {
+      api_set_error(err, kErrorTypeValidation,
+                    "Gave nonempty RHS in unmap command: %s", parsed_args.rhs);
+    } else {
+      api_set_error(err, kErrorTypeValidation, "Gave nonempty RHS for unmap");
+    }
+    goto fail_and_free;
+  }
+
+  // buf_do_map() reads noremap/unmap as its own argument.
+  int maptype_val = 0;
+  if (is_unmap) {
+    maptype_val = 1;
+  } else if (is_noremap) {
+    maptype_val = 2;
+  }
+
+  switch (buf_do_map(maptype_val, &parsed_args, mode_val, 0, target_buf)) {
+  case 0:
+    break;
+  case 1:
+    api_set_error(err, kErrorTypeException, (char *)e_invarg, 0);
+    goto fail_and_free;
+  case 2:
+    api_set_error(err, kErrorTypeException, (char *)e_nomap, 0);
+    goto fail_and_free;
+  case 5:
+    api_set_error(err, kErrorTypeException,
+                  "E227: mapping already exists for %s", parsed_args.lhs);
+    goto fail_and_free;
+  default:
+    assert(false && "Unrecognized return code!");
+    goto fail_and_free;
+  }  // switch
+
+fail_and_free:
+  current_sctx = save_current_sctx;
+  NLUA_CLEAR_REF(parsed_args.rhs_lua);
+  xfree(parsed_args.rhs);
+  xfree(parsed_args.orig_rhs);
+  xfree(parsed_args.desc);
+}
+
+/// Get an array containing dictionaries describing mappings
+/// based on mode and buffer id
+///
+/// @param  mode  The abbreviation for the mode
+/// @param  buf  The buffer to get the mapping array. NULL for global
+/// @param  from_lua  Whether it is called from internal lua api.
+/// @returns Array of maparg()-like dictionaries describing mappings
+ArrayOf(Dictionary) keymap_array(String mode, buf_T *buf, bool from_lua)
+{
+  Array mappings = ARRAY_DICT_INIT;
+  dict_T *const dict = tv_dict_alloc();
+
+  // Convert the string mode to the integer mode
+  // that is stored within each mapblock
+  char *p = mode.data;
+  int int_mode = get_map_mode(&p, 0);
+
+  // Determine the desired buffer value
+  long buffer_value = (buf == NULL) ? 0 : buf->handle;
+
+  for (int i = 0; i < MAX_MAPHASH; i++) {
+    for (const mapblock_T *current_maphash = get_maphash(i, buf);
+         current_maphash;
+         current_maphash = current_maphash->m_next) {
+      if (current_maphash->m_simplified) {
+        continue;
+      }
+      // Check for correct mode
+      if (int_mode & current_maphash->m_mode) {
+        mapblock_fill_dict(dict, current_maphash, buffer_value, false);
+        Object api_dict = vim_to_object((typval_T[]) { { .v_type = VAR_DICT,
+                                                         .vval.v_dict = dict } });
+        if (from_lua) {
+          Dictionary d = api_dict.data.dictionary;
+          for (size_t j = 0; j < d.size; j++) {
+            if (strequal("callback", d.items[j].key.data)) {
+              d.items[j].value.type = kObjectTypeLuaRef;
+              d.items[j].value.data.luaref = api_new_luaref((LuaRef)d.items[j].value.data.integer);
+              break;
+            }
+          }
+        }
+        ADD(mappings, api_dict);
+        tv_dict_clear(dict);
+      }
+    }
+  }
+  tv_dict_free(dict);
+
+  return mappings;
+}