Merge pull request #11338 from bfredl/vvlua

v:lua and better error messages for vimL->lua

3 files changed, 169 insertions, 65 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 3621f90511..9fe92a92cc 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -422,6 +422,7 @@ static struct vimvar {
   VV(VV_TYPE_BOOL,      "t_bool",           VAR_NUMBER, VV_RO),
   VV(VV_ECHOSPACE,      "echospace",        VAR_NUMBER, VV_RO),
   VV(VV_EXITING,        "exiting",          VAR_NUMBER, VV_RO),
+  VV(VV_LUA,            "lua",              VAR_PARTIAL, VV_RO),
 };
 #undef VV
 
@@ -433,11 +434,14 @@ static struct vimvar {
 #define vv_str          vv_di.di_tv.vval.v_string
 #define vv_list         vv_di.di_tv.vval.v_list
 #define vv_dict         vv_di.di_tv.vval.v_dict
+#define vv_partial      vv_di.di_tv.vval.v_partial
 #define vv_tv           vv_di.di_tv
 
 /// Variable used for v:
 static ScopeDictDictItem vimvars_var;
 
+static partial_T *vvlua_partial;
+
 /// v: hashtab
 #define vimvarht  vimvardict.dv_hashtab
 
@@ -639,6 +643,13 @@ void eval_init(void)
 
   set_vim_var_nr(VV_ECHOSPACE,    sc_col - 1);
 
+  vimvars[VV_LUA].vv_type = VAR_PARTIAL;
+  vvlua_partial = xcalloc(1, sizeof(partial_T));
+  vimvars[VV_LUA].vv_partial = vvlua_partial;
+  // this value shouldn't be printed, but if it is, do not crash
+  vvlua_partial->pt_name = xmallocz(0);
+  vvlua_partial->pt_refcount++;
+
   set_reg_var(0);  // default for v:register is not 0 but '"'
 }
 
@@ -1313,12 +1324,25 @@ int call_vim_function(
 {
   int doesrange;
   int ret;
+  int len = (int)STRLEN(func);
+  partial_T *pt = NULL;
+
+  if (len >= 6 && !memcmp(func, "v:lua.", 6)) {
+    func += 6;
+    len = check_luafunc_name((const char *)func, false);
+    if (len == 0) {
+      ret = FAIL;
+      goto fail;
+    }
+    pt = vvlua_partial;
+  }
 
   rettv->v_type = VAR_UNKNOWN;  // tv_clear() uses this.
-  ret = call_func(func, (int)STRLEN(func), rettv, argc, argv, NULL,
+  ret = call_func(func, len, rettv, argc, argv, NULL,
                   curwin->w_cursor.lnum, curwin->w_cursor.lnum,
-                  &doesrange, true, NULL, NULL);
+                  &doesrange, true, pt, NULL);
 
+fail:
   if (ret == FAIL) {
     tv_clear(rettv);
   }
@@ -2462,6 +2486,13 @@ static char_u *get_lval(char_u *const name, typval_T *const rettv,
         }
       }
 
+      if (lp->ll_di != NULL && tv_is_luafunc(&lp->ll_di->di_tv)
+          && len == -1 && rettv == NULL) {
+        tv_clear(&var1);
+        EMSG2(e_illvar, "v:['lua']");
+        return NULL;
+      }
+
       if (lp->ll_di == NULL) {
         // Can't add "v:" or "a:" variable.
         if (lp->ll_dict == &vimvardict
@@ -4699,7 +4730,7 @@ eval_index(
 
   if (evaluate) {
     n1 = 0;
-    if (!empty1 && rettv->v_type != VAR_DICT) {
+    if (!empty1 && rettv->v_type != VAR_DICT && !tv_is_luafunc(rettv)) {
       n1 = tv_get_number(&var1);
       tv_clear(&var1);
     }
@@ -4823,7 +4854,7 @@ eval_index(
         if (len == -1) {
           tv_clear(&var1);
         }
-        if (item == NULL) {
+        if (item == NULL || tv_is_luafunc(&item->di_tv)) {
           return FAIL;
         }
 
@@ -6334,7 +6365,7 @@ static char_u *deref_func_name(const char *name, int *lenp,
  */
 static int
 get_func_tv(
-    char_u *name,           // name of the function
+    const char_u *name,     // name of the function
     int len,                // length of "name"
     typval_T *rettv,
     char_u **arg,           // argument, pointing to the '('
@@ -6590,7 +6621,15 @@ call_func(
     rettv->vval.v_number = 0;
     error = ERROR_UNKNOWN;
 
-    if (!builtin_function((const char *)rfname, -1)) {
+    if (partial == vvlua_partial) {
+      if (len > 0) {
+        error = ERROR_NONE;
+        executor_call_lua((const char *)funcname, len,
+                          argvars, argcount, rettv);
+      } else {
+        error = ERROR_UNKNOWN;
+      }
+    } else if (!builtin_function((const char *)rfname, -1)) {
       // User defined function.
       if (partial != NULL && partial->pt_func != NULL) {
         fp = partial->pt_func;
@@ -6707,14 +6746,14 @@ call_func(
 ///
 /// @param ermsg must be passed without translation (use N_() instead of _()).
 /// @param name function name
-static void emsg_funcname(char *ermsg, char_u *name)
+static void emsg_funcname(char *ermsg, const char_u *name)
 {
   char_u *p;
 
   if (*name == K_SPECIAL) {
     p = concat_str((char_u *)"<SNR>", name + 3);
   } else {
-    p = name;
+    p = (char_u *)name;
   }
 
   EMSG2(_(ermsg), p);
@@ -20168,6 +20207,26 @@ static void check_vars(const char *name, size_t len)
   }
 }
 
+/// check if special v:lua value for calling lua functions
+static bool tv_is_luafunc(typval_T *tv)
+{
+  return tv->v_type == VAR_PARTIAL && tv->vval.v_partial == vvlua_partial;
+}
+
+/// check the function name after "v:lua."
+static int check_luafunc_name(const char *str, bool paren)
+{
+  const char *p = str;
+  while (ASCII_ISALNUM(*p) || *p == '_' || *p == '.') {
+    p++;
+  }
+  if (*p != (paren ? '(' : NUL)) {
+    return 0;
+  } else {
+    return (int)(p-str);
+  }
+}
+
 /// Handle expr[expr], expr[expr:expr] subscript and .name lookup.
 /// Also handle function call with Funcref variable: func(expr)
 /// Can all be combined: dict.func(expr)[idx]['func'](expr)
@@ -20181,9 +20240,30 @@ handle_subscript(
 {
   int ret = OK;
   dict_T      *selfdict = NULL;
-  char_u      *s;
+  const char_u *s;
   int len;
   typval_T functv;
+  int slen = 0;
+  bool lua = false;
+
+  if (tv_is_luafunc(rettv)) {
+    if (**arg != '.') {
+      tv_clear(rettv);
+      ret = FAIL;
+    } else {
+      (*arg)++;
+
+      lua = true;
+      s = (char_u *)(*arg);
+      slen = check_luafunc_name(*arg, true);
+      if (slen == 0) {
+        tv_clear(rettv);
+        ret = FAIL;
+      }
+      (*arg) += slen;
+    }
+  }
+
 
   while (ret == OK
          && (**arg == '['
@@ -20200,14 +20280,16 @@ handle_subscript(
         // Invoke the function.  Recursive!
         if (functv.v_type == VAR_PARTIAL) {
           pt = functv.vval.v_partial;
-          s = partial_name(pt);
+          if (!lua) {
+            s = partial_name(pt);
+          }
         } else {
           s = functv.vval.v_string;
         }
       } else {
         s = (char_u *)"";
       }
-      ret = get_func_tv(s, (int)STRLEN(s), rettv, (char_u **)arg,
+      ret = get_func_tv(s, lua ? slen : (int)STRLEN(s), rettv, (char_u **)arg,
                         curwin->w_cursor.lnum, curwin->w_cursor.lnum,
                         &len, evaluate, pt, selfdict);
 
@@ -22039,8 +22121,19 @@ trans_function_name(
       *pp = (char_u *)end;
     } else if (lv.ll_tv->v_type == VAR_PARTIAL
                && lv.ll_tv->vval.v_partial != NULL) {
-      name = vim_strsave(partial_name(lv.ll_tv->vval.v_partial));
-      *pp = (char_u *)end;
+      if (lv.ll_tv->vval.v_partial == vvlua_partial && *end == '.') {
+        len = check_luafunc_name((const char *)end+1, true);
+        if (len == 0) {
+          EMSG2(e_invexpr2, "v:lua");
+          goto theend;
+        }
+        name = xmallocz(len);
+        memcpy(name, end+1, len);
+        *pp = (char_u *)end+1+len;
+      } else {
+        name = vim_strsave(partial_name(lv.ll_tv->vval.v_partial));
+        *pp = (char_u *)end;
+      }
       if (partial != NULL) {
         *partial = lv.ll_tv->vval.v_partial;
       }
diff --git a/src/nvim/eval.h b/src/nvim/eval.h
index e099de831a..2aa08e2074 100644
--- a/src/nvim/eval.h
+++ b/src/nvim/eval.h
@@ -117,6 +117,7 @@ typedef enum {
     VV_TYPE_BOOL,
     VV_ECHOSPACE,
     VV_EXITING,
+    VV_LUA,
 } VimVarIndex;
 
 /// All recognized msgpack types
diff --git a/src/nvim/lua/executor.c b/src/nvim/lua/executor.c
index 5e5cb0cea5..093c130c5f 100644
--- a/src/nvim/lua/executor.c
+++ b/src/nvim/lua/executor.c
@@ -48,9 +48,6 @@ typedef struct {
 # include "lua/executor.c.generated.h"
 #endif
 
-/// Name of the run code for use in messages
-#define NLUA_EVAL_NAME "<VimL compiled string>"
-
 /// Convert lua error into a Vim error message
 ///
 /// @param  lstate  Lua interpreter state.
@@ -397,29 +394,6 @@ static lua_State *nlua_enter(void)
   return lstate;
 }
 
-/// Execute lua string
-///
-/// @param[in]  str  String to execute.
-/// @param[out]  ret_tv  Location where result will be saved.
-///
-/// @return Result of the execution.
-void executor_exec_lua(const String str, typval_T *const ret_tv)
-  FUNC_ATTR_NONNULL_ALL
-{
-  lua_State *const lstate = nlua_enter();
-
-  if (luaL_loadbuffer(lstate, str.data, str.size, NLUA_EVAL_NAME)) {
-    nlua_error(lstate, _("E5104: Error while creating lua chunk: %.*s"));
-    return;
-  }
-  if (lua_pcall(lstate, 0, 1, 0)) {
-    nlua_error(lstate, _("E5105: Error while calling lua chunk: %.*s"));
-    return;
-  }
-
-  nlua_pop_typval(lstate, ret_tv);
-}
-
 static void nlua_print_event(void **argv)
 {
   char *str = argv[0];
@@ -732,10 +706,6 @@ void executor_eval_lua(const String str, typval_T *const arg,
                        typval_T *const ret_tv)
   FUNC_ATTR_NONNULL_ALL
 {
-  lua_State *const lstate = nlua_enter();
-
-  garray_T str_ga;
-  ga_init(&str_ga, 1, 80);
 #define EVALHEADER "local _A=select(1,...) return ("
   const size_t lcmd_len = sizeof(EVALHEADER) - 1 + str.size + 1;
   char *lcmd;
@@ -748,30 +718,71 @@ void executor_eval_lua(const String str, typval_T *const arg,
   memcpy(lcmd + sizeof(EVALHEADER) - 1, str.data, str.size);
   lcmd[lcmd_len - 1] = ')';
 #undef EVALHEADER
-  if (luaL_loadbuffer(lstate, lcmd, lcmd_len, NLUA_EVAL_NAME)) {
-    nlua_error(lstate,
-               _("E5107: Error while creating lua chunk for luaeval(): %.*s"));
-    if (lcmd != (char *)IObuff) {
-      xfree(lcmd);
-    }
-    return;
-  }
+  typval_exec_lua(lcmd, lcmd_len, "luaeval()", arg, 1, true, ret_tv);
+
   if (lcmd != (char *)IObuff) {
     xfree(lcmd);
   }
+}
 
-  if (arg->v_type == VAR_UNKNOWN) {
-    lua_pushnil(lstate);
+void executor_call_lua(const char *str, size_t len, typval_T *const args,
+                       int argcount, typval_T *ret_tv)
+  FUNC_ATTR_NONNULL_ALL
+{
+#define CALLHEADER "return "
+#define CALLSUFFIX "(...)"
+  const size_t lcmd_len = sizeof(CALLHEADER) - 1 + len + sizeof(CALLSUFFIX) - 1;
+  char *lcmd;
+  if (lcmd_len < IOSIZE) {
+    lcmd = (char *)IObuff;
   } else {
-    nlua_push_typval(lstate, arg, true);
+    lcmd = xmalloc(lcmd_len);
+  }
+  memcpy(lcmd, CALLHEADER, sizeof(CALLHEADER) - 1);
+  memcpy(lcmd + sizeof(CALLHEADER) - 1, str, len);
+  memcpy(lcmd + sizeof(CALLHEADER) - 1 + len, CALLSUFFIX,
+         sizeof(CALLSUFFIX) - 1);
+#undef CALLHEADER
+#undef CALLSUFFIX
+
+  typval_exec_lua(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)
+{
+  if (check_restricted() || check_secure()) {
+    ret_tv->v_type = VAR_NUMBER;
+    ret_tv->vval.v_number = 0;
+    return;
   }
-  if (lua_pcall(lstate, 1, 1, 0)) {
-    nlua_error(lstate,
-               _("E5108: Error while calling lua chunk for luaeval(): %.*s"));
+
+  lua_State *const lstate = nlua_enter();
+  if (luaL_loadbuffer(lstate, lcmd, lcmd_len, name)) {
+    nlua_error(lstate, _("E5107: Error loading lua %.*s"));
     return;
   }
 
-  nlua_pop_typval(lstate, ret_tv);
+  for (int i = 0; i < argcount; i++) {
+    if (args[i].v_type == VAR_UNKNOWN) {
+      lua_pushnil(lstate);
+    } else {
+      nlua_push_typval(lstate, &args[i], special);
+    }
+  }
+  if (lua_pcall(lstate, argcount, ret_tv ? 1 : 0, 0)) {
+    nlua_error(lstate, _("E5108: Error executing lua %.*s"));
+    return;
+  }
+
+  if (ret_tv) {
+    nlua_pop_typval(lstate, ret_tv);
+  }
 }
 
 /// Execute lua string
@@ -857,9 +868,8 @@ void ex_lua(exarg_T *const eap)
     xfree(code);
     return;
   }
-  typval_T tv = { .v_type = VAR_UNKNOWN };
-  executor_exec_lua((String) { .data = code, .size = len }, &tv);
-  tv_clear(&tv);
+  typval_exec_lua(code, len, ":lua", NULL, 0, false, NULL);
+
   xfree(code);
 }
 
@@ -897,8 +907,8 @@ void ex_luado(exarg_T *const eap)
 #undef DOSTART
 #undef DOEND
 
-  if (luaL_loadbuffer(lstate, lcmd, lcmd_len, NLUA_EVAL_NAME)) {
-    nlua_error(lstate, _("E5109: Error while creating lua chunk: %.*s"));
+  if (luaL_loadbuffer(lstate, lcmd, lcmd_len, ":luado")) {
+    nlua_error(lstate, _("E5109: Error loading lua: %.*s"));
     if (lcmd_len >= IOSIZE) {
       xfree(lcmd);
     }
@@ -908,7 +918,7 @@ void ex_luado(exarg_T *const eap)
     xfree(lcmd);
   }
   if (lua_pcall(lstate, 0, 1, 0)) {
-    nlua_error(lstate, _("E5110: Error while creating lua function: %.*s"));
+    nlua_error(lstate, _("E5110: Error executing lua: %.*s"));
     return;
   }
   for (linenr_T l = eap->line1; l <= eap->line2; l++) {
@@ -919,7 +929,7 @@ void ex_luado(exarg_T *const eap)
     lua_pushstring(lstate, (const char *)ml_get_buf(curbuf, l, false));
     lua_pushnumber(lstate, (lua_Number)l);
     if (lua_pcall(lstate, 2, 1, 0)) {
-      nlua_error(lstate, _("E5111: Error while calling lua function: %.*s"));
+      nlua_error(lstate, _("E5111: Error calling lua: %.*s"));
       break;
     }
     if (lua_isstring(lstate, -1)) {