Merge pull request #12235 from dm1try/add_init_lua

add init.lua as an alternative user config

src/nvim/lua/executor.c

@@ -927,7 +927,7 @@ void nlua_typval_eval(const String str, typval_T *const arg,
   memcpy(lcmd + sizeof(EVALHEADER) - 1, str.data, str.size);
   lcmd[lcmd_len - 1] = ')';
 #undef EVALHEADER
-  typval_exec_lua(lcmd, lcmd_len, "luaeval()", arg, 1, true, ret_tv);
+  nlua_typval_exec(lcmd, lcmd_len, "luaeval()", arg, 1, true, ret_tv);
 
   if (lcmd != (char *)IObuff) {
     xfree(lcmd);
@@ -954,16 +954,16 @@ void nlua_typval_call(const char *str, size_t len, typval_T *const args,
 #undef CALLHEADER
 #undef CALLSUFFIX
 
-  typval_exec_lua(lcmd, lcmd_len, "v:lua", args, argcount, false, ret_tv);
+  nlua_typval_exec(lcmd, lcmd_len, "v:lua", args, argcount, false, ret_tv);
 
   if (lcmd != (char *)IObuff) {
     xfree(lcmd);
   }
 }
 
-static void typval_exec_lua(const char *lcmd, size_t lcmd_len, const char *name,
-                            typval_T *const args, int argcount, bool special,
-                            typval_T *ret_tv)
+static void nlua_typval_exec(const char *lcmd, size_t lcmd_len,
+                             const char *name, typval_T *const args,
+                             int argcount, bool special, typval_T *ret_tv)
 {
   if (check_secure()) {
     if (ret_tv) {
@@ -1140,7 +1140,7 @@ void ex_lua(exarg_T *const eap)
     xfree(code);
     return;
   }
-  typval_exec_lua(code, len, ":lua", NULL, 0, false, NULL);
+  nlua_typval_exec(code, len, ":lua", NULL, 0, false, NULL);
 
   xfree(code);
 }
@@ -1230,18 +1230,31 @@ void ex_luado(exarg_T *const eap)
 /// @param  eap  VimL command being run.
 void ex_luafile(exarg_T *const eap)
   FUNC_ATTR_NONNULL_ALL
+{
+  nlua_exec_file((const char *)eap->arg);
+}
+
+/// execute lua code from a file.
+///
+/// @param  path  path of the file
+///
+/// @return  true if everything ok, false if there was an error (echoed)
+bool nlua_exec_file(const char *path)
+  FUNC_ATTR_NONNULL_ALL
 {
   lua_State *const lstate = nlua_enter();
 
-  if (luaL_loadfile(lstate, (const char *)eap->arg)) {
+  if (luaL_loadfile(lstate, path)) {
     nlua_error(lstate, _("E5112: Error while creating lua chunk: %.*s"));
-    return;
+    return false;
   }
 
   if (lua_pcall(lstate, 0, 0, 0)) {
     nlua_error(lstate, _("E5113: Error while calling lua chunk: %.*s"));
-    return;
+    return false;
   }
+
+  return true;
 }
 
 static void nlua_add_treesitter(lua_State *const lstate) FUNC_ATTR_NONNULL_ALL

src/nvim/main.c

@@ -1069,9 +1069,14 @@ static void command_line_scan(mparm_T *parmp)
               } else {
                 a = argv[0];
               }
-              size_t s_size = STRLEN(a) + 4;
+
+              size_t s_size = STRLEN(a) + 9;
               char *s = xmalloc(s_size);
-              snprintf(s, s_size, "so %s", a);
+              if (path_with_extension(a, "lua")) {
+                snprintf(s, s_size, "luafile %s", a);
+              } else {
+                snprintf(s, s_size, "so %s", a);
+              }
               parmp->cmds_tofree[parmp->n_commands] = true;
               parmp->commands[parmp->n_commands++] = s;
             } else {
@@ -1770,6 +1775,23 @@ static bool do_user_initialization(void)
     do_exrc = p_exrc;
     return do_exrc;
   }
+
+  char_u *init_lua_path = (char_u *)stdpaths_user_conf_subpath("init.lua");
+  if (os_path_exists(init_lua_path)
+      && nlua_exec_file((const char *)init_lua_path)) {
+    os_setenv("MYVIMRC", (const char *)init_lua_path, 1);
+    char_u *vimrc_path = (char_u *)stdpaths_user_conf_subpath("init.vim");
+
+    if (os_path_exists(vimrc_path)) {
+      EMSG3(_("Conflicting configs: \"%s\" \"%s\""), init_lua_path, vimrc_path);
+    }
+
+    xfree(vimrc_path);
+    xfree(init_lua_path);
+    return false;
+  }
+  xfree(init_lua_path);
+
   char_u *user_vimrc = (char_u *)stdpaths_user_conf_subpath("init.vim");
   if (do_source(user_vimrc, true, DOSO_VIMRC) != FAIL) {
     do_exrc = p_exrc;
@@ -1829,8 +1851,12 @@ static void source_startup_scripts(const mparm_T *const parmp)
         || strequal(parmp->use_vimrc, "NORC")) {
       // Do nothing.
     } else {
-      if (do_source((char_u *)parmp->use_vimrc, false, DOSO_NONE) != OK) {
-        EMSG2(_("E282: Cannot read from \"%s\""), parmp->use_vimrc);
+      if (path_with_extension(parmp->use_vimrc, "lua")) {
+        nlua_exec_file(parmp->use_vimrc);
+      } else {
+        if (do_source((char_u *)parmp->use_vimrc, false, DOSO_NONE) != OK) {
+          EMSG2(_("E282: Cannot read from \"%s\""), parmp->use_vimrc);
+        }
       }
     }
   } else if (!silent_mode) {

src/nvim/path.c

@@ -1704,6 +1704,13 @@ int path_with_url(const char *fname)
   return path_is_url(p);
 }
 
+bool path_with_extension(const char *path, const char *extension)
+{
+  const char *last_dot = strrchr(path, '.');
+  if (!last_dot) { return false; }
+  return strcmp(last_dot + 1, extension) == 0;
+}
+
 /*
  * Return TRUE if "name" is a full (absolute) path name or URL.
  */