feat(:source, nvim_exec): line numbers in :verbose output

Support showing line numbers for Vim script sourced anonymously via :source (no
args) and nvim_exec.

Do not offset the line number shown from anonymous scripts with the line number
of an enclosing script. For example, this could produce incorrect numbers in
situations where we have escaped NLs:

```vim
echo "hi"
call nvim_exec("\n\n\nset cul", 1)
verbose set cul?
```
Would print "line 6" (preferably "line 5"), but it's actually on line 2...

TODO: ideally, we should say something instead, like:
"Last set from anonymous :source (script id X) line 4 in script.vim line 2"

TODO: see verbose_spec.lua comment, anonymous sources in Lua need to be fixed so
they can be <SID>ed like regular anon sources, but neovim#15079 broke that...

src/nvim/ex_cmds2.c

@@ -1790,6 +1790,7 @@ static FILE *fopen_noinh_readbin(char *filename)
 typedef struct {
   char_u *buf;
   size_t offset;
+  linenr_T sourcing_lnum;
 } GetStrLineCookie;
 
 /// Get one full line from a sourced string (in-memory, no file).
@@ -1799,7 +1800,7 @@ typedef struct {
 ///         some error.
 static char_u *get_str_line(int c, void *cookie, int indent, bool do_concat)
 {
-  GetStrLineCookie *p = cookie;
+  GetStrLineCookie *const p = cookie;
   if (STRLEN(p->buf) <= p->offset) {
     return NULL;
   }
@@ -1808,13 +1809,15 @@ static char_u *get_str_line(int c, void *cookie, int indent, bool do_concat)
   garray_T ga;
   ga_init(&ga, sizeof(char_u), 400);
   ga_concat_len(&ga, (const char *)line, (size_t)(eol - line));
+  sourcing_lnum = ++p->sourcing_lnum;
   if (do_concat && vim_strchr(p_cpo, CPO_CONCAT) == NULL) {
     while (eol[0] != NUL) {
       line = eol + 1;
       const char_u *const next_eol = skip_to_newline(line);
       if (!concat_continued_line(&ga, 400, line, (size_t)(next_eol - line))) {
         break;
       }
+      p->sourcing_lnum++;
       eol = next_eol;
     }
   }
@@ -1875,7 +1878,7 @@ static int source_using_linegetter(void *cookie, LineGetter fgetline, const char
   const sctx_T save_current_sctx = current_sctx;
   current_sctx.sc_sid = sid;
   current_sctx.sc_seq = sid > 0 ? ++last_current_SID_seq : 0;
-  current_sctx.sc_lnum = save_sourcing_lnum;
+  current_sctx.sc_lnum = 0;
   funccal_entry_T entry;
   save_funccal(&entry);
   const int retval
@@ -1911,6 +1914,7 @@ static void cmd_source_buffer(const exarg_T *const eap)
   const GetStrLineCookie cookie = {
     .buf = ga.ga_data,
     .offset = 0,
+    .sourcing_lnum = 0,
   };
   if (curbuf->b_fname && path_with_extension((const char *)curbuf->b_fname, "lua")) {
     nlua_source_using_linegetter(get_str_line, (void *)&cookie, ":source (no file)");
@@ -1934,6 +1938,7 @@ int do_source_str(const char *cmd, const char *traceback_name)
   GetStrLineCookie cookie = {
     .buf = (char_u *)cmd,
     .offset = 0,
+    .sourcing_lnum = 0,
   };
   const scid_T sid = current_sctx.sc_sid == SID_LUA ? SID_LUA : ++last_current_SID;
   return source_using_linegetter((void *)&cookie, get_str_line, traceback_name, sid);
@@ -2344,9 +2349,12 @@ void free_scriptnames(void)
 
 linenr_T get_sourced_lnum(LineGetter fgetline, void *cookie)
 {
-  return fgetline == getsourceline
-        ? ((struct source_cookie *)cookie)->sourcing_lnum
-        : sourcing_lnum;
+  if (fgetline == getsourceline) {
+    return ((struct source_cookie *)cookie)->sourcing_lnum;
+  } else if (fgetline == get_str_line) {
+    return ((GetStrLineCookie *)cookie)->sourcing_lnum;
+  }
+  return sourcing_lnum;
 }
 
 

test/functional/api/vim_spec.lua

@@ -92,8 +92,8 @@ describe('API', function()
 
     it(':verbose set {option}?', function()
       nvim('exec', 'set nowrap', false)
-      eq('nowrap\n\tLast set from anonymous :source (script id 1)',
-        nvim('exec', 'verbose set wrap?', true))
+      eq('nowrap\n\tLast set from anonymous :source (script id 1) line 1',
+         nvim('exec', 'verbose set wrap?', true))
     end)
 
     it('multiline input', function()
@@ -240,13 +240,13 @@ describe('API', function()
       local sourcing_fname = tmpname()
       write_file(sourcing_fname, 'call nvim_exec("source '..fname..'", v:false)\n')
       meths.exec('set verbose=2', false)
-      local traceback_output = 'line 0: sourcing "'..sourcing_fname..'"\n'..
-        'line 0: sourcing "'..fname..'"\n'..
+      local traceback_output = 'line 1: sourcing "'..sourcing_fname..'"\n'..
+        'line 1: sourcing "'..fname..'"\n'..
         'hello\n'..
         'finished sourcing '..fname..'\n'..
         'continuing in nvim_exec() called at '..sourcing_fname..':1\n'..
         'finished sourcing '..sourcing_fname..'\n'..
-        'continuing in nvim_exec() called at nvim_exec():0'
+        'continuing in nvim_exec() called at nvim_exec():1'
       eq(traceback_output,
         meths.exec('call nvim_exec("source '..sourcing_fname..'", v:false)', true))
       os.remove(fname)
@@ -279,7 +279,7 @@ describe('API', function()
       ]]}
     end)
 
-    it('does\'t display messages when output=true', function()
+    it('doesn\'t display messages when output=true', function()
       local screen = Screen.new(40, 8)
       screen:attach()
       screen:set_default_attr_ids({
@@ -297,6 +297,48 @@ describe('API', function()
                                                 |
       ]]}
     end)
+
+    it(':verbose shows correct line numbers', function()
+      -- should work like test_vimscript's Test_function_defined_line()
+      local code = [[
+        " F1
+        func F1()
+            " F2
+            func F2()
+                "
+                "
+                "
+                return
+            endfunc
+            " F3
+            execute "func F3()\n\n\n\nreturn\nendfunc"
+            " F4
+            execute "func F4()\n
+                        \\n
+                        \\n
+                        \\n
+                        \return\n
+                        \endfunc"
+        endfunc
+        " F5
+        execute "func F5()\n\n\n\nreturn\nendfunc"
+        " F6
+        execute "func F6()\n
+                    \\n
+                    \\n
+                    \\n
+                    \return\n
+                    \endfunc"
+        call F1()
+      ]]
+      meths.exec(code, false)
+      matches('line 2\n', meths.exec('verbose func F1', true))
+      matches('line 4\n', meths.exec('verbose func F2', true))
+      matches('line 11\n', meths.exec('verbose func F3', true))
+      matches('line 13\n', meths.exec('verbose func F4', true))
+      matches('line 21\n', meths.exec('verbose func F5', true))
+      matches('line 23\n', meths.exec('verbose func F6', true))
+    end)
   end)
 
   describe('nvim_command', function()

test/functional/ex_cmds/verbose_spec.lua

@@ -139,9 +139,11 @@ test_group  FileType
 
   it('"Last set" works with anonymous sid', function()
     local result = exec_capture(':verbose set tw?')
+    -- TODO(seandewar): should be 27, but ideally should display something like
+    -- "Last set from anonymous :source (script id <blah>) line 5 in <script_location> line 23"
     eq(string.format([[
   textwidth=80
-	Last set from %s line 23]],
+	Last set from %s line 28]],
        script_location), result)
 
     -- Different anon execs in the same file should have unique SIDs as usual.

test/functional/legacy/assert_spec.lua

@@ -145,10 +145,10 @@ describe('assert function:', function()
         call assert_true('', 'file two')
       ]])
       expected_errors({
-        "nvim_exec(): equal assertion failed: Expected 1 but got 100",
-        "nvim_exec(): true  assertion failed: Expected False but got 'true'",
-        "nvim_exec(): false assertion failed: Expected True but got 'false'",
-        "nvim_exec(): file two: Expected True but got ''",
+        "nvim_exec() line 1: equal assertion failed: Expected 1 but got 100",
+        "nvim_exec() line 2: true  assertion failed: Expected False but got 'true'",
+        "nvim_exec() line 3: false assertion failed: Expected True but got 'false'",
+        "nvim_exec() line 1: file two: Expected True but got ''",
       })
     end)
   end)