feat(:source, nvim_exec): support script-local variables

Based on #13143 (and #11507) with changes:

 - Omit script_type_E. Use sn_name == NULL to determine anon items.
 - Keep SID_STR. Used by anon :source for .lua files (no item).
 - Show SID in get_scriptname output (:verbose set).
 - Factor item creation into new_script_item.
 - Leave sc_seq = 0 (anon scripts don't re-use the same item when re-sourced).
 - Add tests for anon :source.

Co-authored-by: Vikram Pal <vikrampal659@gmail.com>
Co-authored-by: Justin M. Keyes <justinkz@gmail.com>

4 files changed, 75 insertions, 24 deletions

diff --git a/src/nvim/ex_cmds2.c b/src/nvim/ex_cmds2.c
index c3cde2f15a..c421d3991c 100644
--- a/src/nvim/ex_cmds2.c
+++ b/src/nvim/ex_cmds2.c
@@ -1939,6 +1939,29 @@ static char_u *get_str_line(int c, void *cookie, int indent, bool do_concat)
   return ga.ga_data;
 }
 
+/// Create a new script item and allocate script-local vars. @see new_script_vars
+///
+/// @param  name  File name of the script. NULL for anonymous :source.
+/// @param[out]  sid_out  SID of the new item.
+/// @return pointer to the created script item.
+static scriptitem_T *new_script_item(char_u *const name, scid_T *const sid_out)
+{
+  static scid_T last_current_SID = 0;
+  const scid_T sid = ++last_current_SID;
+  if (sid_out != NULL) {
+    *sid_out = sid;
+  }
+  ga_grow(&script_items, (int)(sid - script_items.ga_len));
+  while (script_items.ga_len < sid) {
+    script_items.ga_len++;
+    SCRIPT_ITEM(script_items.ga_len).sn_name = NULL;
+    SCRIPT_ITEM(script_items.ga_len).sn_prof_on = false;
+  }
+  SCRIPT_ITEM(sid).sn_name = name;
+  new_script_vars(sid);  // Allocate the local script variables to use for this script.
+  return &SCRIPT_ITEM(sid);
+}
+
 static int source_using_linegetter(void *cookie, LineGetter fgetline, const char *traceback_name)
 {
   char_u *save_sourcing_name = sourcing_name;
@@ -1955,7 +1978,7 @@ static int source_using_linegetter(void *cookie, LineGetter fgetline, const char
   sourcing_lnum = 0;
 
   const sctx_T save_current_sctx = current_sctx;
-  current_sctx.sc_sid = SID_STR;
+  new_script_item(NULL, &current_sctx.sc_sid);
   current_sctx.sc_seq = 0;
   current_sctx.sc_lnum = save_sourcing_lnum;
   funccal_entry_T entry;
@@ -2036,7 +2059,6 @@ int do_source(char_u *fname, int check_other, int is_vimrc)
   char_u *fname_exp;
   char_u *firstline = NULL;
   int retval = FAIL;
-  static scid_T last_current_SID = 0;
   static int last_current_SID_seq = 0;
   int save_debug_break_level = debug_break_level;
   scriptitem_T *si = NULL;
@@ -2183,15 +2205,7 @@ int do_source(char_u *fname, int check_other, int is_vimrc)
     }
   }
   if (current_sctx.sc_sid == 0) {
-    current_sctx.sc_sid = ++last_current_SID;
-    ga_grow(&script_items, (int)(current_sctx.sc_sid - script_items.ga_len));
-    while (script_items.ga_len < current_sctx.sc_sid) {
-      script_items.ga_len++;
-      SCRIPT_ITEM(script_items.ga_len).sn_name = NULL;
-      SCRIPT_ITEM(script_items.ga_len).sn_prof_on = false;
-    }
-    si = &SCRIPT_ITEM(current_sctx.sc_sid);
-    si->sn_name = fname_exp;
+    si = new_script_item(fname_exp, &current_sctx.sc_sid);
     fname_exp = vim_strsave(si->sn_name);  // used for autocmd
     if (file_id_ok) {
       si->file_id_valid = true;
@@ -2199,9 +2213,6 @@ int do_source(char_u *fname, int check_other, int is_vimrc)
     } else {
       si->file_id_valid = false;
     }
-
-    // Allocate the local script variables to use for this script.
-    new_script_vars(current_sctx.sc_sid);
   }
 
   if (l_do_profiling == PROF_YES) {
@@ -2375,16 +2386,21 @@ char_u *get_scriptname(LastSet last_set, bool *should_free)
   case SID_LUA:
     return (char_u *)_("Lua");
   case SID_API_CLIENT:
-    vim_snprintf((char *)IObuff, IOSIZE,
-                 _("API client (channel id %" PRIu64 ")"),
-                 last_set.channel_id);
+    snprintf((char *)IObuff, IOSIZE, _("API client (channel id %" PRIu64 ")"), last_set.channel_id);
     return IObuff;
   case SID_STR:
     return (char_u *)_("anonymous :source");
-  default:
+  default: {
+    char_u *const sname = SCRIPT_ITEM(last_set.script_ctx.sc_sid).sn_name;
+    if (sname == NULL) {
+      snprintf((char *)IObuff, IOSIZE, _("anonymous :source (script id %d)"),
+               last_set.script_ctx.sc_sid);
+      return IObuff;
+    }
+
     *should_free = true;
-    return home_replace_save(NULL,
-                             SCRIPT_ITEM(last_set.script_ctx.sc_sid).sn_name);
+    return home_replace_save(NULL, sname);
+  }
   }
 }
 
diff --git a/src/nvim/globals.h b/src/nvim/globals.h
index 182e88083a..435949379b 100644
--- a/src/nvim/globals.h
+++ b/src/nvim/globals.h
@@ -335,7 +335,7 @@ EXTERN int garbage_collect_at_exit INIT(= false);
 #define SID_WINLAYOUT   -7      // changing window size
 #define SID_LUA         -8      // for Lua scripts/chunks
 #define SID_API_CLIENT  -9      // for API clients
-#define SID_STR         -10     // for sourcing a string
+#define SID_STR         -10     // for sourcing a string with no script item
 
 // Script CTX being sourced or was sourced to define the current function.
 EXTERN sctx_T current_sctx INIT(= { 0 COMMA 0 COMMA 0 });
diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index 6b644ed519..f878a50a26 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -89,7 +89,7 @@ describe('API', function()
 
     it(':verbose set {option}?', function()
       nvim('exec', 'set nowrap', false)
-      eq('nowrap\n\tLast set from anonymous :source',
+      eq('nowrap\n\tLast set from anonymous :source (script id 1)',
         nvim('exec', 'verbose set wrap?', true))
     end)
 
@@ -132,6 +132,29 @@ describe('API', function()
       -- try no spaces before continuations to catch off-by-one error
       nvim('exec', 'let ab = #{\n\\a: 98,\n"\\ b: 2\n\\}', false)
       eq({a = 98}, request('nvim_eval', 'g:ab'))
+
+      -- Script scope (s:)
+      eq('ahoy! script-scoped varrrrr', nvim('exec', [[
+          let s:pirate = 'script-scoped varrrrr'
+          function! s:avast_ye_hades(s) abort
+            return a:s .. ' ' .. s:pirate
+          endfunction
+          echo <sid>avast_ye_hades('ahoy!')
+        ]], true))
+
+      eq('ahoy! script-scoped varrrrr', nvim('exec', [[
+          let s:pirate = 'script-scoped varrrrr'
+          function! Avast_ye_hades(s) abort
+            return a:s .. ' ' .. s:pirate
+          endfunction
+          echo nvim_exec('echo Avast_ye_hades(''ahoy!'')', 1)
+        ]], true))
+
+      eq('Vim(call):E5555: API call: Vim(echo):E121: Undefined variable: s:pirate',
+        pcall_err(request, 'nvim_exec', [[
+          let s:pirate = 'script-scoped varrrrr'
+          call nvim_exec('echo s:pirate', 1)
+        ]], false))
     end)
 
     it('non-ASCII input', function()
diff --git a/test/functional/ex_cmds/source_spec.lua b/test/functional/ex_cmds/source_spec.lua
index bdf6ae76d1..8077b22e56 100644
--- a/test/functional/ex_cmds/source_spec.lua
+++ b/test/functional/ex_cmds/source_spec.lua
@@ -25,11 +25,14 @@ describe(':source', function()
       let b = #{
         \ k: "v"
        "\ (o_o)
-        \ }]])
+        \ }
+      let s:s = 0zbeef.cafe
+      let c = s:s]])
 
     command('source')
     eq('2', meths.exec('echo a', true))
     eq("{'k': 'v'}", meths.exec('echo b', true))
+    eq("0zBEEFCAFE", meths.exec('echo c', true))
 
     exec('set cpoptions+=C')
     eq('Vim(let):E15: Invalid expression: #{', exc_exec('source'))
@@ -43,7 +46,11 @@ describe(':source', function()
       let b = #{
        "\ (>_<)
         \ K: "V"
-        \ }]])
+        \ }
+      function! s:C() abort
+        return expand("<SID>") .. "C()"
+      endfunction
+      let D = {-> s:C()}]])
 
     -- Source the 2nd line only
     feed('ggjV')
@@ -55,6 +62,11 @@ describe(':source', function()
     feed_command(':source')
     eq('4', meths.exec('echo a', true))
     eq("{'K': 'V'}", meths.exec('echo b', true))
+    eq("<SNR>3_C()", meths.exec('echo D()', true))
+
+    -- Source last line only
+    feed_command(':$source')
+    eq('Vim(echo):E117: Unknown function: s:C', exc_exec('echo D()'))
 
     exec('set cpoptions+=C')
     eq('Vim(let):E15: Invalid expression: #{', exc_exec("'<,'>source"))