vim-patch:partial:9.1.0482: termdebug plugin needs more love (#29329)

Problem:  termdebug plugin needs more love
Solution: start with some more Vim9 refactoring
          to improve maintenance and readability
          (Ubaldo Tiberi)

List of Changes and the Reasoning Behind Them:

1) Introduction of InitScriptVariables() Function:

Reasoning: This function has been introduced to ensure that when you open and
close Termdebug, and then open it again, there are no leftover script variable
values from the previous session. Leftover values could potentially cause
issues. The goal is for each Termdebug session to be independent of previous
sessions. At startup, all script variables are initialized. The only exception
is g:termdebug_loaded located at the very beginning of the script to prevent
sourcing the script twice. The variables are declared at script level and
defined in InitScriptVariables().

2) More Descriptive Variable Names:

Reasoning: The names of variables have been made more comprehensive. Almost
every Termdebug buffer now has a variable to indicate its name and another
variable to indicate its number, improving code readability and
maintainability. Due to the latest discussion around the &mousemodel option
save/restore mechanism, perhaps some other variables shall be prepended with
saved_.

3) Consistent Naming for GDB Terminal Buffers:

Reasoning: The name of the GDB terminal buffer now matches the name of the GDB
program being used, e.g., 'gdb', 'mygdb', 'arm-eabi-none-gdb', etc. This
ensures clarity and consistency in identifying buffers.

4) Other minor improvements:
Moved EchoErr() on top, added another test, some refactoring, mainly changed
several 0 and 1 to true and false

closes: vim/vim#14980

https://github.com/vim/vim/commit/ef8eab86e29091eaff0d3fb0bc3f7c90f468f6aa

Co-authored-by: Ubaldo Tiberi <ubaldo.tiberi@volvo.com>

2 files changed, 74 insertions, 62 deletions

diff --git a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
index f78a082cb7..9d5d3f5b96 100644
--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -44,8 +44,13 @@
 " - job_info && term_getjob -> nvim_get_chan_info
 " - balloon -> vim.lsp.util.open_floating_preview
 
+func s:Echoerr(msg)
+  echohl ErrorMsg | echom '[termdebug] ' .. a:msg | echohl None
+endfunc
+
 " In case this gets sourced twice.
 if exists(':Termdebug')
+  call s:Echoerr('Termdebug already loaded.')
   finish
 endif
 
@@ -67,8 +72,8 @@ command -nargs=+ -complete=file -bang TermdebugCommand call s:StartDebugCommand(
 let s:pc_id = 12
 let s:asm_id = 13
 let s:break_id = 14  " breakpoint number is added to this
-let s:stopped = 1
-let s:running = 0
+let s:stopped = v:true
+let s:running = v:false
 
 let s:parsing_disasm_msg = 0
 let s:asm_lines = []
@@ -121,10 +126,6 @@ func s:GetCommand()
   return type(cmd) == v:t_list ? copy(cmd) : [cmd]
 endfunc
 
-func s:Echoerr(msg)
-  echohl ErrorMsg | echom '[termdebug] ' .. a:msg | echohl None
-endfunc
-
 func s:StartDebug(bang, ...)
   " First argument is the command to debug, second core file or process ID.
   call s:StartDebug_internal({'gdb_args': a:000, 'bang': a:bang})
@@ -149,9 +150,9 @@ func s:StartDebug_internal(dict)
   let s:ptywin = 0
   let s:pid = 0
   let s:asmwin = 0
-  let s:asmbuf = 0
+  let s:asmbufnr = 0
   let s:varwin = 0
-  let s:varbuf = 0
+  let s:varbufnr = 0
 
   if exists('#User#TermdebugStartPre')
     doauto <nomodeline> User TermdebugStartPre
@@ -168,7 +169,7 @@ func s:StartDebug_internal(dict)
   let s:signcolumn_buflist = [bufnr()]
 
   let s:save_columns = 0
-  let s:allleft = 0
+  let s:allleft = v:false
   let wide = 0
   if exists('g:termdebug_config')
     let wide = get(g:termdebug_config, 'wide', 0)
@@ -181,11 +182,11 @@ func s:StartDebug_internal(dict)
       let &columns = wide
       " If we make the Vim window wider, use the whole left half for the debug
       " windows.
-      let s:allleft = 1
+      let s:allleft = v:true
     endif
-    let s:vertical = 1
+    let s:vertical = v:true
   else
-    let s:vertical = 0
+    let s:vertical = v:false
   endif
 
   " Override using a terminal window by setting g:termdebug_use_prompt to 1.
@@ -226,24 +227,24 @@ endfunc
 
 " Use when debugger didn't start or ended.
 func s:CloseBuffers()
-  exe 'bwipe! ' . s:ptybuf
-  if s:asmbuf > 0 && bufexists(s:asmbuf)
-    exe 'bwipe! ' . s:asmbuf
+  exe 'bwipe! ' . s:ptybufnr
+  if s:asmbufnr > 0 && bufexists(s:asmbufnr)
+    exe 'bwipe! ' . s:asmbufnr
   endif
-  if s:varbuf > 0 && bufexists(s:varbuf)
-    exe 'bwipe! ' . s:varbuf
+  if s:varbufnr > 0 && bufexists(s:varbufnr)
+    exe 'bwipe! ' . s:varbufnr
   endif
-  let s:running = 0
+  let s:running = v:false
   unlet! s:gdbwin
 endfunc
 
-func s:CheckGdbRunning()
+func s:IsGdbStarted()
   if !s:gdb_running
     call s:Echoerr(string(s:GetCommand()[0]) . ' exited unexpectedly')
     call s:CloseBuffers()
-    return ''
+    return v:false
   endif
-  return 'ok'
+  return v:true
 endfunc
 
 " Open a terminal window without a job, to run the debugged program in.
@@ -258,7 +259,7 @@ func s:StartDebug_term(dict)
     return
   endif
   let pty_job_info = nvim_get_chan_info(s:pty_job_id)
-  let s:ptybuf = pty_job_info['buffer']
+  let s:ptybufnr = pty_job_info['buffer']
   let pty = pty_job_info['pty']
   let s:ptywin = win_getid()
   if s:vertical
@@ -279,11 +280,11 @@ func s:StartDebug_term(dict)
   " hide terminal buffer
   if s:comm_job_id == 0
     call s:Echoerr('Invalid argument (or job table is full) while opening communication terminal window')
-    exe 'bwipe! ' . s:ptybuf
+    exe 'bwipe! ' . s:ptybufnr
     return
   elseif s:comm_job_id == -1
     call s:Echoerr('Failed to open the communication terminal window')
-    exe 'bwipe! ' . s:ptybuf
+    exe 'bwipe! ' . s:ptybufnr
     return
   endif
   let comm_job_info = nvim_get_chan_info(s:comm_job_id)
@@ -324,7 +325,7 @@ func s:StartDebug_term(dict)
   let s:gdb_job_id = termopen(gdb_cmd, {'on_exit': function('s:EndTermDebug')})
   if s:gdb_job_id == 0
     call s:Echoerr('Invalid argument (or job table is full) while opening gdb terminal window')
-    exe 'bwipe! ' . s:ptybuf
+    exe 'bwipe! ' . s:ptybufnr
     return
   elseif s:gdb_job_id == -1
     call s:Echoerr('Failed to open the gdb terminal window')
@@ -334,18 +335,18 @@ func s:StartDebug_term(dict)
   let s:gdb_running = v:true
   let s:starting = v:true
   let gdb_job_info = nvim_get_chan_info(s:gdb_job_id)
-  let s:gdbbuf = gdb_job_info['buffer']
+  let s:gdbbufnr = gdb_job_info['buffer']
   let s:gdbwin = win_getid()
 
   " Wait for the "startupdone" message before sending any commands.
   let try_count = 0
   while 1
-    if s:CheckGdbRunning() != 'ok'
+    if !s:IsGdbStarted()
       return
     endif
 
     for lnum in range(1, 200)
-      if get(getbufline(s:gdbbuf, lnum), 0, '') =~ 'startupdone'
+      if get(getbufline(s:gdbbufnr, lnum), 0, '') =~ 'startupdone'
         let try_count = 9999
         break
       endif
@@ -371,14 +372,14 @@ func s:StartDebug_term(dict)
   " why the debugger doesn't work.
   let try_count = 0
   while 1
-    if s:CheckGdbRunning() != 'ok'
+    if !s:IsGdbStarted()
       return
     endif
 
     let response = ''
     for lnum in range(1, 200)
-      let line1 = get(getbufline(s:gdbbuf, lnum), 0, '')
-      let line2 = get(getbufline(s:gdbbuf, lnum + 1), 0, '')
+      let line1 = get(getbufline(s:gdbbufnr, lnum), 0, '')
+      let line2 = get(getbufline(s:gdbbufnr, lnum + 1), 0, '')
       if line1 =~ 'new-ui mi '
         " response can be in the same line or the next line
         let response = line1 . line2
@@ -472,7 +473,7 @@ func s:StartDebug_prompt(dict)
         \ })
   if s:gdbjob == 0
     call s:Echoerr('Invalid argument (or job table is full) while starting gdb job')
-    exe 'bwipe! ' . s:ptybuf
+    exe 'bwipe! ' . s:ptybufnr
     return
   elseif s:gdbjob == -1
     call s:Echoerr('Failed to start the gdb job')
@@ -481,7 +482,7 @@ func s:StartDebug_prompt(dict)
   endif
   exe $'au BufUnload <buffer={s:promptbuf}> ++once call jobstop(s:gdbjob)'
 
-  let s:ptybuf = 0
+  let s:ptybufnr = 0
   if has('win32')
     " MS-Windows: run in a new console window for maximum compatibility
     call s:SendCommand('set new-console on')
@@ -498,7 +499,7 @@ func s:StartDebug_prompt(dict)
       return
     endif
     let pty_job_info = nvim_get_chan_info(s:pty_job_id)
-    let s:ptybuf = pty_job_info['buffer']
+    let s:ptybufnr = pty_job_info['buffer']
     let pty = pty_job_info['pty']
     let s:ptywin = win_getid()
     call s:SendCommand('tty ' . pty)
@@ -602,7 +603,7 @@ endfunc
 func s:SendResumingCommand(cmd)
   if s:stopped
     " reset s:stopped here, it may take a bit of time before we get a response
-    let s:stopped = 0
+    let s:stopped = v:false
     " call ch_log('assume that program is running after this command')
     call s:SendCommand(a:cmd)
   " else
@@ -776,16 +777,16 @@ endfunc
 func s:EndDebugCommon()
   let curwinid = win_getid()
 
-  if exists('s:ptybuf') && s:ptybuf
-    exe 'bwipe! ' . s:ptybuf
+  if exists('s:ptybufnr') && s:ptybufnr
+    exe 'bwipe! ' . s:ptybufnr
   endif
-  if s:asmbuf > 0 && bufexists(s:asmbuf)
-    exe 'bwipe! ' . s:asmbuf
+  if s:asmbufnr > 0 && bufexists(s:asmbufnr)
+    exe 'bwipe! ' . s:asmbufnr
   endif
-  if s:varbuf > 0 && bufexists(s:varbuf)
-    exe 'bwipe! ' . s:varbuf
+  if s:varbufnr > 0 && bufexists(s:varbufnr)
+    exe 'bwipe! ' . s:varbufnr
   endif
-  let s:running = 0
+  let s:running = v:false
 
   " Restore 'signcolumn' in all buffers for which it was set.
   call win_gotoid(s:sourcewin)
@@ -1186,7 +1187,7 @@ endfunc
 func s:Until(at)
   if s:stopped
     " reset s:stopped here, it may take a bit of time before we get a response
-    let s:stopped = 0
+    let s:stopped = v:false
     " call ch_log('assume that program is running after this command')
     " Use the fname:lnum format
     let at = empty(a:at) ?
@@ -1322,9 +1323,9 @@ func s:Evaluate(range, arg)
     return
   endif
   let expr = s:GetEvaluationExpression(a:range, a:arg)
-  let s:evalFromBalloonExpr = 1
+  let s:evalFromBalloonExpr = v:true
   let s:evalFromBalloonExprResult = ''
-  let s:ignoreEvalError = 0
+  let s:ignoreEvalError = v:false
   call s:SendEval(expr)
 endfunc
 
@@ -1343,12 +1344,12 @@ func s:GetEvaluationExpression(range, arg)
     let expr = s:CleanupExpr(@v)
     call setpos('.', pos)
     call setreg('v', reg, regt)
-    let s:evalFromBalloonExpr = 1
+    let s:evalFromBalloonExpr = v:true
   else
     " no evaluation provided: get from C-expression under cursor
     " TODO: allow filetype specific lookup #9057
     let expr = expand('<cexpr>')
-    let s:evalFromBalloonExpr = 1
+    let s:evalFromBalloonExpr = v:true
   endif
   return expr
 endfunc
@@ -1376,8 +1377,8 @@ func s:CleanupExpr(expr)
   return expr
 endfunc
 
-let s:ignoreEvalError = 0
-let s:evalFromBalloonExpr = 0
+let s:ignoreEvalError = v:false
+let s:evalFromBalloonExpr = v:false
 let s:evalFromBalloonExprResult = ''
 
 let s:eval_float_win_id = -1
@@ -1419,7 +1420,7 @@ func s:HandleEvaluate(msg)
 
   if s:evalexpr[0] != '*' && value =~ '^0x' && value != '0x0' && value !~ '"$'
     " Looks like a pointer, also display what it points to.
-    let s:ignoreEvalError = 1
+    let s:ignoreEvalError = v:true
     call s:SendEval('*' . s:evalexpr)
   endif
 endfunc
@@ -1428,8 +1429,8 @@ endfunc
 func s:HandleError(msg)
   if s:ignoreEvalError
     " Result of s:SendEval() failed, ignore.
-    let s:ignoreEvalError = 0
-    let s:evalFromBalloonExpr = 0
+    let s:ignoreEvalError = v:false
+    let s:evalFromBalloonExpr = v:false
     return
   endif
   let msgVal = substitute(a:msg, '.*msg="\(.*\)"', '\1', '')
@@ -1489,11 +1490,11 @@ func s:GotoAsmwinOrCreateIt()
     setlocal signcolumn=no
     setlocal modifiable
 
-    if s:asmbuf > 0 && bufexists(s:asmbuf)
-      exe 'buffer' . s:asmbuf
+    if s:asmbufnr > 0 && bufexists(s:asmbufnr)
+      exe 'buffer' . s:asmbufnr
     elseif empty(glob('Termdebug-asm-listing'))
       silent file Termdebug-asm-listing
-      let s:asmbuf = bufnr('Termdebug-asm-listing')
+      let s:asmbufnr = bufnr('Termdebug-asm-listing')
     else
       call s:Echoerr("You have a file/folder named 'Termdebug-asm-listing'.
           \ Please exit and rename it because Termdebug may not work as expected.")
@@ -1561,11 +1562,11 @@ func s:GotoVariableswinOrCreateIt()
     setlocal signcolumn=no
     setlocal modifiable
 
-    if s:varbuf > 0 && bufexists(s:varbuf)
-      exe 'buffer' . s:varbuf
+    if s:varbufnr > 0 && bufexists(s:varbufnr)
+      exe 'buffer' . s:varbufnr
     elseif empty(glob('Termdebug-variables-listing'))
       silent file Termdebug-variables-listing
-      let s:varbuf = bufnr('Termdebug-variables-listing')
+      let s:varbufnr = bufnr('Termdebug-variables-listing')
     else
       call s:Echoerr("You have a file/folder named 'Termdebug-variables-listing'.
           \ Please exit and rename it because Termdebug may not work as expected.")
@@ -1588,14 +1589,14 @@ func s:HandleCursor(msg)
 
   if a:msg =~ '^\*stopped'
     "call ch_log('program stopped')
-    let s:stopped = 1
+    let s:stopped = v:true
     if a:msg =~ '^\*stopped,reason="exited-normally"'
-      let s:running = 0
+      let s:running = v:false
     endif
   elseif a:msg =~ '^\*running'
     "call ch_log('program running')
-    let s:stopped = 0
-    let s:running = 1
+    let s:stopped = v:false
+    let s:running = v:true
   endif
 
   if a:msg =~ 'fullname='
diff --git a/test/old/testdir/test_termdebug.vim b/test/old/testdir/test_termdebug.vim
index fd0c850577..38278cb326 100644
--- a/test/old/testdir/test_termdebug.vim
+++ b/test/old/testdir/test_termdebug.vim
@@ -340,5 +340,16 @@ func Test_termdebug_bufnames()
   unlet g:termdebug_config
 endfunc
 
+function Test_termdebug_save_restore_variables()
+  let &mousemodel=''
+  Termdebug
+  call WaitForAssert({-> assert_equal(3, winnr('$'))})
+  call WaitForAssert({-> assert_match(&mousemodel, 'popup_setpos')})
+  wincmd t
+  quit!
+  call WaitForAssert({-> assert_equal(1, winnr('$'))})
+  call WaitForAssert({-> assert_true(empty(&mousemodel))})
+endfunction
+
 
 " vim: shiftwidth=2 sts=2 expandtab