feat(treesitter): allow customizing language symbol name

runtime/doc/treesitter.txt

@@ -387,16 +387,20 @@ inspect_language({lang})                                  *inspect_language()*
     Parameters: ~
         {lang}  The language.
 
-require_language({lang}, {path}, {silent})                *require_language()*
+                                                          *require_language()*
+require_language({lang}, {path}, {silent}, {symbol_name})
     Asserts that the provided language is installed, and optionally provide a
     path for the parser
 
     Parsers are searched in the `parser` runtime directory.
 
     Parameters: ~
-        {lang}    The language the parser should parse
-        {path}    Optional path the parser is located at
-        {silent}  Don't throw an error if language not found
+        {lang}         (string) The language the parser should parse
+        {path}         (string|nil) Optional path the parser is located at
+        {silent}       (boolean|nil) Don't throw an error if language not
+                       found
+        {symbol_name}  (string|nil) Internal symbol name for the language to
+                       load
 
 
 ==============================================================================

runtime/lua/vim/treesitter/language.lua

@@ -6,10 +6,11 @@ local M = {}
 ---
 --- Parsers are searched in the `parser` runtime directory.
 ---
----@param lang The language the parser should parse
----@param path Optional path the parser is located at
----@param silent Don't throw an error if language not found
-function M.require_language(lang, path, silent)
+---@param lang string The language the parser should parse
+---@param path string|nil Optional path the parser is located at
+---@param silent boolean|nil Don't throw an error if language not found
+---@param symbol_name string|nil Internal symbol name for the language to load
+function M.require_language(lang, path, silent, symbol_name)
   if vim._ts_has_language(lang) then
     return true
   end
@@ -21,7 +22,6 @@ function M.require_language(lang, path, silent)
         return false
       end
 
-      -- TODO(bfredl): help tag?
       error("no parser for '" .. lang .. "' language, see :help treesitter-parsers")
     end
     path = paths[1]
@@ -29,10 +29,10 @@ function M.require_language(lang, path, silent)
 
   if silent then
     return pcall(function()
-      vim._ts_add_language(path, lang)
+      vim._ts_add_language(path, lang, symbol_name)
     end)
   else
-    vim._ts_add_language(path, lang)
+    vim._ts_add_language(path, lang, symbol_name)
   end
 
   return true

src/nvim/lua/treesitter.c

@@ -14,10 +14,12 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <uv.h>
 
 #include "nvim/api/private/helpers.h"
 #include "nvim/buffer.h"
 #include "nvim/lib/kvec.h"
+#include "nvim/log.h"
 #include "nvim/lua/treesitter.h"
 #include "nvim/memline.h"
 #include "tree_sitter/api.h"
@@ -145,18 +147,27 @@ int tslua_has_language(lua_State *L)
   return 1;
 }
 
+// Creates the language into the internal language map.
+//
+// Returns true if the language is correctly loaded in the language map
 int tslua_add_language(lua_State *L)
 {
   const char *path = luaL_checkstring(L, 1);
   const char *lang_name = luaL_checkstring(L, 2);
+  const char *symbol_name = lang_name;
+
+  if (lua_gettop(L) >= 3 && !lua_isnil(L, 3)) {
+    symbol_name = luaL_checkstring(L, 3);
+  }
 
   if (pmap_has(cstr_t)(&langs, lang_name)) {
-    return 0;
+    lua_pushboolean(L, true);
+    return 1;
   }
 
 #define BUFSIZE 128
   char symbol_buf[BUFSIZE];
-  snprintf(symbol_buf, BUFSIZE, "tree_sitter_%s", lang_name);
+  snprintf(symbol_buf, BUFSIZE, "tree_sitter_%s", symbol_name);
 #undef BUFSIZE
 
   uv_lib_t lib;
@@ -179,6 +190,7 @@ int tslua_add_language(lua_State *L)
 
   TSLanguage *lang = lang_parser();
   if (lang == NULL) {
+    uv_dlclose(&lib);
     return luaL_error(L, "Failed to load parser %s: internal error", path);
   }
 

test/functional/treesitter/language_spec.lua

@@ -10,7 +10,7 @@ local pending_c_parser = helpers.pending_c_parser
 
 before_each(clear)
 
-describe('treesitter API', function()
+describe('treesitter language API', function()
   -- error tests not requiring a parser library
   it('handles missing language', function()
     eq("Error executing lua: .../language.lua:0: no parser for 'borklang' language, see :help treesitter-parsers",
@@ -26,6 +26,9 @@ describe('treesitter API', function()
 
     eq("Error executing lua: .../language.lua:0: no parser for 'borklang' language, see :help treesitter-parsers",
        pcall_err(exec_lua, "parser = vim.treesitter.inspect_language('borklang')"))
+
+    matches("Error executing lua: Failed to load parser: uv_dlsym: .+",
+       pcall_err(exec_lua, "parser = vim.treesitter.require_language('c', nil, false, 'borklang')"))
   end)
 
   it('inspects language', function()