vim-patch:9.2.0143: termdebug: no support for thread and condition in :Break

Problem:  termdebug :Break does not support `thread` and `if` arguments
Solution: extend :Break and :Tbreak to accept optional location, thread
          {nr}, and if {expr} arguments (Yinzuo Jiang).

closes: vim/vim#19613

5890ea5397

AI-assisted: Codex

runtime/doc/terminal.txt

@@ -398,11 +398,25 @@ gdb:
  `:Arguments` {args}  set arguments for the next `:Run`
 
  *:Break*	set a breakpoint at the cursor position
- :Break {position}
+ :Break [{position}] [thread {nr}] [if {expr}]
 		set a breakpoint at the specified position
+		if {position} is omitted, use the current file and line
+		thread {nr} limits the breakpoint to one thread
+		if {expr} sets a conditional breakpoint
+		Examples: >
+			:Break if argc == 1
+			:Break 42 thread 3 if x > 10
+			:Break main
+<
  *:Tbreak*	set a temporary breakpoint at the cursor position
- :Tbreak {position}
-		set a temporary breakpoint at the specified position
+ :Tbreak [{position}] [thread {nr}] [if {expr}]
+		like `:Break`, but the breakpoint is deleted after
+		it is hit once
+		Examples: >
+			:Tbreak if argc == 1
+			:Tbreak 42 thread 3 if x > 10
+			:Tbreak main
+<
  *:Clear*	delete the breakpoint at the cursor position
 
  *:Step*	execute the gdb "step" command

runtime/pack/dist/opt/termdebug/plugin/termdebug.vim

@@ -2,7 +2,7 @@
 "
 " Author: Bram Moolenaar
 " Copyright: Vim license applies, see ":help license"
-" Last Change: 2025 Jul 08
+" Last Change: 2026 Mar 11
 "
 " WORK IN PROGRESS - The basics works stable, more to come
 " Note: In general you need at least GDB 7.12 because this provides the
@@ -1186,6 +1186,86 @@ func s:QuoteArg(x)
   return printf('"%s"', a:x->substitute('[\\"]', '\\&', 'g'))
 endfunc
 
+func s:DefaultBreakpointLocation()
+  " Use the fname:lnum format, older gdb can't handle --source.
+  return s:QuoteArg($"{expand('%:p')}:{line('.')}")
+endfunc
+
+func s:TokenizeBreakpointArguments(args)
+  let tokens = []
+  let start = -1
+  let escaped = v:false
+  let in_quotes = v:false
+
+  let i = 0
+  for ch in a:args
+    if start < 0 && ch !~# '\s'
+      let start = i
+    endif
+    if start >= 0
+      if escaped
+        let escaped = v:false
+      elseif ch ==# '\'
+        let escaped = v:true
+      elseif ch ==# '"'
+        let in_quotes = !in_quotes
+      elseif !in_quotes && ch =~# '\s'
+        eval tokens->add(#{text: a:args->slice(start, i), start: start, end: i - 1})
+        let start = -1
+      endif
+    endif
+    let i += 1
+  endfor
+
+  if start >= 0
+    eval tokens->add(#{text: a:args->slice(start), start: start, end: i - 1})
+  endif
+  return tokens
+endfunc
+
+func s:BuildBreakpointCommand(at, tbreak)
+  let args = trim(a:at)
+  let cmd = '-break-insert'
+  if a:tbreak
+    let cmd ..= ' -t'
+  endif
+
+  if empty(args)
+    return $'{cmd} {s:DefaultBreakpointLocation()}'
+  endif
+
+  let condition = ''
+  let prefix = args
+  for token in s:TokenizeBreakpointArguments(args)
+    if token.text ==# 'if' && token.end < strchars(args) - 1
+      let condition = trim(args->slice(token.end + 1))
+      let prefix = token.start > 0 ? trim(args->slice(0, token.start)) : ''
+      break
+    endif
+  endfor
+
+  let prefix_tokens = s:TokenizeBreakpointArguments(prefix)
+  let location = prefix
+  let thread = ''
+  if len(prefix_tokens) >= 2
+        \ && prefix_tokens[-2].text ==# 'thread'
+        \ && prefix_tokens[-1].text =~# '^\d\+$'
+    let thread = prefix_tokens[-1].text
+    let location = join(prefix_tokens[: -3]->mapnew('v:val.text'), ' ')
+  endif
+
+  if empty(trim(location))
+    let location = s:DefaultBreakpointLocation()
+  endif
+  if !empty(thread)
+    let cmd ..= $' -p {thread}'
+  endif
+  if !empty(condition)
+    let cmd ..= $' -c {s:QuoteArg(condition)}'
+  endif
+  return $'{cmd} {trim(location)}'
+endfunc
+
 " :Until - Execute until past a specified position or current line
 func s:Until(at)
   if s:stopped
@@ -1211,13 +1291,7 @@ func s:SetBreakpoint(at, tbreak=v:false)
     sleep 10m
   endif
 
-  " Use the fname:lnum format, older gdb can't handle --source.
-  let at = empty(a:at) ? s:QuoteArg($"{expand('%:p')}:{line('.')}") : a:at
-  if a:tbreak
-    let cmd = $'-break-insert -t {at}'
-  else
-    let cmd = $'-break-insert {at}'
-  endif
+  let cmd = s:BuildBreakpointCommand(a:at, a:tbreak)
   call s:SendCommand(cmd)
   if do_continue
     Continue

test/old/testdir/test_plugin_termdebug.vim

@@ -77,6 +77,96 @@ endfunction
 
 packadd termdebug
 
+func s:GetTermdebugFunction(name)
+  for line in execute('scriptnames')->split("\n")
+    if line =~# 'termdebug/plugin/termdebug\.vim$'
+      let sid = matchstr(line, '^\s*\zs\d\+')
+      return function('<SNR>' .. sid .. '_' .. a:name)
+    endif
+  endfor
+  throw 'termdebug script not found'
+endfunc
+
+func Test_termdebug_break_command_builder()
+  let bin_name = 'XTD_break_cmd'
+  let src_name = bin_name .. '.c'
+  let BuildBreakpointCommand = s:GetTermdebugFunction('BuildBreakpointCommand')
+  call s:generate_files(bin_name)
+
+  execute 'edit ' .. src_name
+  call cursor(22, 1)
+  let here = '"' .. fnamemodify(src_name, ':p') .. ':22"'
+
+  call assert_equal('-break-insert ' .. here, BuildBreakpointCommand('', v:false))
+  call assert_equal('-break-insert -t ' .. here, BuildBreakpointCommand('', v:true))
+  call assert_equal('-break-insert -c "argc == 1" ' .. here,
+        \ BuildBreakpointCommand('if argc == 1', v:false))
+  call assert_equal('-break-insert -p 2 ' .. here,
+        \ BuildBreakpointCommand('thread 2', v:false))
+  call assert_equal('-break-insert -p 2 -c "argc == 1" ' .. here,
+        \ BuildBreakpointCommand('thread 2 if argc == 1', v:false))
+  call assert_equal('-break-insert -p 2 -c "argc == 1" 22',
+        \ BuildBreakpointCommand('22 thread 2 if argc == 1', v:false))
+  call assert_equal('-break-insert -c "argc == 1" 22',
+        \ BuildBreakpointCommand('22 if argc == 1', v:false))
+  call assert_equal('-break-insert -c "é == 1" 断点',
+        \ BuildBreakpointCommand('断点 if é == 1', v:false))
+  call assert_equal('-break-insert -p 2 断点',
+        \ BuildBreakpointCommand('断点 thread 2', v:false))
+  call assert_equal('-break-insert 断点 if',
+        \ BuildBreakpointCommand('断点 if', v:false))
+  call assert_equal('-break-insert 断点 thread 2 if',
+        \ BuildBreakpointCommand('断点 thread 2 if', v:false))
+  call assert_equal('-break-insert foo\ if\ bar',
+        \ BuildBreakpointCommand('foo\ if\ bar', v:false))
+
+  call s:cleanup_files(bin_name)
+  %bw!
+endfunc
+
+func Test_termdebug_break_with_default_location_and_condition()
+  let g:test_is_flaky = 1
+  let bin_name = 'XTD_break_if'
+  let src_name = bin_name .. '.c'
+  call s:generate_files(bin_name)
+
+  execute 'edit ' .. src_name
+  execute 'Termdebug ./' .. bin_name
+  call WaitForAssert({-> assert_true(get(g:, "termdebug_is_running", v:false))})
+  call WaitForAssert({-> assert_equal(3, winnr('$'))})
+  let gdb_buf = winbufnr(1)
+  wincmd b
+
+  call cursor(22, 1)
+  Break if argc == 1
+  call Nterm_wait(gdb_buf)
+  redraw!
+  call WaitForAssert({-> assert_equal([
+        \ {'lnum': 22, 'id': 1014, 'name': 'debugBreakpoint1.0',
+        \  'priority': 110, 'group': 'TermDebug'}],
+        \ sign_getplaced('', #{group: 'TermDebug'})[0].signs)})
+
+  Run
+  call Nterm_wait(gdb_buf, 400)
+  redraw!
+  call WaitForAssert({-> assert_equal([
+        \ {'lnum': 22, 'id': 12, 'name': 'debugPC', 'priority': 110,
+        \  'group': 'TermDebug'},
+        \ {'lnum': 22, 'id': 1014, 'name': 'debugBreakpoint1.0',
+        \  'priority': 110, 'group': 'TermDebug'}],
+        \ sign_getplaced('', #{group: 'TermDebug'})[0].signs->reverse())})
+
+  Continue
+  call Nterm_wait(gdb_buf)
+  wincmd t
+  quit!
+  redraw!
+  call WaitForAssert({-> assert_equal(1, winnr('$'))})
+
+  call s:cleanup_files(bin_name)
+  %bw!
+endfunc
+
 func Test_termdebug_basic()
   let g:test_is_flaky = 1
   let bin_name = 'XTD_basic'