patch 9.1.0935: SpotBugs compiler can be improved

Problem:  SpotBugs compiler can be improved
Solution: runtime(compiler): Improve defaults and error handling for
          SpotBugs; update test_compiler.vim (Aliaksei Budavei)

runtime(compiler): Improve defaults and error handling for SpotBugs

* Keep "spotbugs#DefaultPreCompilerTestAction()" defined but
  do not assign its Funcref to the "PreCompilerTestAction"
  key of "g:spotbugs_properties": there are no default and
  there can only be introduced arbitrary "*sourceDirPath"
  entries; therefore, this assignment is confusing at best,
  given that the function's implementation delegates to
  whatever "PreCompilerAction" is.

* Allow for the possibility of relative source pathnames
  passed as arguments to Vim for the Javac default actions,
  and the necessity to have them properly reconciled when
  the current working directory is changed.

* Do not expect users to remember or know that new source
  files ‘must be’ ":argadd"'d to be then known to the Javac
  default actions; so collect the names of Java-file buffers
  and Java-file Vim arguments; and let users providing the
  "@sources" file-lists in the "g:javac_makeprg_params"
  variable update these file-lists themselves.

* Strive to not leave behind a fire-once Syntax ":autocmd"
  for a Java buffer whenever an arbitrary pre-compile action
  errors out.

* Only attempt to run a post-compiler action in the absence
  of failures for a pre-compiler action.  Note that warnings
  and failures are treated alike (?!) by the Javac compiler,
  so when previews are tried out with "--enable-preview",
  remember about passing "-Xlint:-preview" too to also let
  SpotBugs have a go.

* Properly group conditional operators when testing for key
  entries in a user-defined variable.

* Also test whether "javaExternal" is defined when choosing
  an implementation for source-file parsing.

* Two commands are provided to toggle actions for buffer-local
  autocommands:
  - SpotBugsRemoveBufferAutocmd;
  - SpotBugsDefineBufferAutocmd.

For example, try this from "~/.vim/after/ftplugin/java.vim":
------------------------------------------------------------
if exists(':SpotBugsDefineBufferAutocmd') == 2
	SpotBugsDefineBufferAutocmd BufWritePost SigUSR1
endif
------------------------------------------------------------

And ":doautocmd java_spotbugs User" can be manually used at will.

closes: #16140

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/autoload/spotbugs.vim b/runtime/autoload/spotbugs.vim
index 9161395..e226207 100644
--- a/runtime/autoload/spotbugs.vim
+++ b/runtime/autoload/spotbugs.vim
@@ -1,10 +1,51 @@
-" Default pre- and post-compiler actions for SpotBugs
+" Default pre- and post-compiler actions and commands for SpotBugs
 " Maintainers:  @konfekt and @zzzyxwvut
-" Last Change:  2024 Nov 27
+" Last Change:  2024 Dec 08
 
 let s:save_cpo = &cpo
 set cpo&vim
 
+" Look for the setting of "g:spotbugs#state" in "ftplugin/java.vim".
+let s:state = get(g:, 'spotbugs#state', {})
+let s:commands = get(s:state, 'commands', {})
+let s:compiler = get(s:state, 'compiler', '')
+let s:readable = filereadable($VIMRUNTIME . '/compiler/' . s:compiler . '.vim')
+
+if has_key(s:commands, 'DefaultPreCompilerCommand')
+  let g:SpotBugsPreCompilerCommand = s:commands.DefaultPreCompilerCommand
+else
+
+  function! s:DefaultPreCompilerCommand(arguments) abort
+    execute 'make ' . a:arguments
+    cc
+  endfunction
+
+  let g:SpotBugsPreCompilerCommand = function('s:DefaultPreCompilerCommand')
+endif
+
+if has_key(s:commands, 'DefaultPreCompilerTestCommand')
+  let g:SpotBugsPreCompilerTestCommand = s:commands.DefaultPreCompilerTestCommand
+else
+
+  function! s:DefaultPreCompilerTestCommand(arguments) abort
+    execute 'make ' . a:arguments
+    cc
+  endfunction
+
+  let g:SpotBugsPreCompilerTestCommand = function('s:DefaultPreCompilerTestCommand')
+endif
+
+if has_key(s:commands, 'DefaultPostCompilerCommand')
+  let g:SpotBugsPostCompilerCommand = s:commands.DefaultPostCompilerCommand
+else
+
+  function! s:DefaultPostCompilerCommand(arguments) abort
+    execute 'make ' . a:arguments
+  endfunction
+
+  let g:SpotBugsPostCompilerCommand = function('s:DefaultPostCompilerCommand')
+endif
+
 if v:version > 900
 
   function! spotbugs#DeleteClassFiles() abort
@@ -127,25 +168,21 @@
 
 function! spotbugs#DefaultPostCompilerAction() abort
   " Since v7.4.191.
-  make %:S
+  call call(g:SpotBugsPostCompilerCommand, ['%:S'])
 endfunction
 
-" Look for "spotbugs#compiler" in "ftplugin/java.vim".
-let s:compiler = exists('spotbugs#compiler') ? spotbugs#compiler : ''
-let s:readable = filereadable($VIMRUNTIME . '/compiler/' . s:compiler . '.vim')
-
 if s:readable && s:compiler ==# 'maven' && executable('mvn')
 
   function! spotbugs#DefaultPreCompilerAction() abort
     call spotbugs#DeleteClassFiles()
     compiler maven
-    make compile
+    call call(g:SpotBugsPreCompilerCommand, ['compile'])
   endfunction
 
   function! spotbugs#DefaultPreCompilerTestAction() abort
     call spotbugs#DeleteClassFiles()
     compiler maven
-    make test-compile
+    call call(g:SpotBugsPreCompilerTestCommand, ['test-compile'])
   endfunction
 
   function! spotbugs#DefaultProperties() abort
@@ -156,10 +193,10 @@
             \ function('spotbugs#DefaultPreCompilerTestAction'),
         \ 'PostCompilerAction':
             \ function('spotbugs#DefaultPostCompilerAction'),
-        \ 'sourceDirPath':      'src/main/java',
-        \ 'classDirPath':       'target/classes',
-        \ 'testSourceDirPath':  'src/test/java',
-        \ 'testClassDirPath':   'target/test-classes',
+        \ 'sourceDirPath':      ['src/main/java'],
+        \ 'classDirPath':       ['target/classes'],
+        \ 'testSourceDirPath':  ['src/test/java'],
+        \ 'testClassDirPath':   ['target/test-classes'],
         \ }
   endfunction
 
@@ -169,13 +206,13 @@
   function! spotbugs#DefaultPreCompilerAction() abort
     call spotbugs#DeleteClassFiles()
     compiler ant
-    make compile
+    call call(g:SpotBugsPreCompilerCommand, ['compile'])
   endfunction
 
   function! spotbugs#DefaultPreCompilerTestAction() abort
     call spotbugs#DeleteClassFiles()
     compiler ant
-    make compile-test
+    call call(g:SpotBugsPreCompilerTestCommand, ['compile-test'])
   endfunction
 
   function! spotbugs#DefaultProperties() abort
@@ -186,28 +223,55 @@
             \ function('spotbugs#DefaultPreCompilerTestAction'),
         \ 'PostCompilerAction':
             \ function('spotbugs#DefaultPostCompilerAction'),
-        \ 'sourceDirPath':      'src',
-        \ 'classDirPath':       'build/classes',
-        \ 'testSourceDirPath':  'test',
-        \ 'testClassDirPath':   'build/test/classes',
+        \ 'sourceDirPath':      ['src'],
+        \ 'classDirPath':       ['build/classes'],
+        \ 'testSourceDirPath':  ['test'],
+        \ 'testClassDirPath':   ['build/test/classes'],
         \ }
   endfunction
 
   unlet s:readable s:compiler
 elseif s:readable && s:compiler ==# 'javac' && executable('javac')
+  let s:filename = tempname()
 
   function! spotbugs#DefaultPreCompilerAction() abort
     call spotbugs#DeleteClassFiles()
     compiler javac
 
     if get(b:, 'javac_makeprg_params', get(g:, 'javac_makeprg_params', '')) =~ '\s@\S'
-      " Read options and filenames from @options [@sources ...].
-      make
+      " Only read options and filenames from @options [@sources ...] and do
+      " not update these files when filelists change.
+      call call(g:SpotBugsPreCompilerCommand, [''])
     else
-      " Let Javac figure out what files to compile.
-      execute 'make ' . join(map(filter(copy(v:argv),
-          \ "v:val =~# '\\.java\\=$'"),
-          \ 'shellescape(v:val)'), ' ')
+      " Collect filenames so that Javac can figure out what to compile.
+      let filelist = []
+
+      for arg_num in range(argc(-1))
+        let arg_name = argv(arg_num)
+
+        if arg_name =~# '\.java\=$'
+          call add(filelist, fnamemodify(arg_name, ':p:S'))
+        endif
+      endfor
+
+      for buf_num in range(1, bufnr('$'))
+        if !buflisted(buf_num)
+          continue
+        endif
+
+        let buf_name = bufname(buf_num)
+
+        if buf_name =~# '\.java\=$'
+          let buf_name = fnamemodify(buf_name, ':p:S')
+
+          if index(filelist, buf_name) < 0
+            call add(filelist, buf_name)
+          endif
+        endif
+      endfor
+
+      noautocmd call writefile(filelist, s:filename)
+      call call(g:SpotBugsPreCompilerCommand, [shellescape('@' . s:filename)])
     endif
   endfunction
 
@@ -219,14 +283,13 @@
     return {
         \ 'PreCompilerAction':
             \ function('spotbugs#DefaultPreCompilerAction'),
-        \ 'PreCompilerTestAction':
-            \ function('spotbugs#DefaultPreCompilerTestAction'),
         \ 'PostCompilerAction':
             \ function('spotbugs#DefaultPostCompilerAction'),
         \ }
   endfunction
 
-  unlet s:readable s:compiler
+  unlet s:readable s:compiler g:SpotBugsPreCompilerTestCommand
+  delfunction! s:DefaultPreCompilerTestCommand
 else
 
   function! spotbugs#DefaultPreCompilerAction() abort
@@ -241,10 +304,49 @@
     return {}
   endfunction
 
-  unlet s:readable
+  " XXX: Keep "s:compiler" around for "spotbugs#DefaultPreCompilerAction()",
+  " "s:DefaultPostCompilerCommand" -- "spotbugs#DefaultPostCompilerAction()".
+  unlet s:readable g:SpotBugsPreCompilerCommand g:SpotBugsPreCompilerTestCommand
+  delfunction! s:DefaultPreCompilerCommand
+  delfunction! s:DefaultPreCompilerTestCommand
 endif
 
+function! s:DefineBufferAutocmd(event, ...) abort
+  if !exists('#java_spotbugs#User')
+    return 1
+  endif
+
+  for l:event in insert(copy(a:000), a:event)
+    if l:event != 'User'
+      execute printf('silent! autocmd! java_spotbugs %s <buffer>', l:event)
+      execute printf('autocmd java_spotbugs %s <buffer> doautocmd User', l:event)
+    endif
+  endfor
+
+  return 0
+endfunction
+
+function! s:RemoveBufferAutocmd(event, ...) abort
+  if !exists('#java_spotbugs')
+    return 1
+  endif
+
+  for l:event in insert(copy(a:000), a:event)
+    if l:event != 'User'
+      execute printf('silent! autocmd! java_spotbugs %s <buffer>', l:event)
+    endif
+  endfor
+
+  return 0
+endfunction
+
+" Documented in ":help compiler-spotbugs".
+command! -bar -nargs=+ -complete=event SpotBugsDefineBufferAutocmd
+    \ call s:DefineBufferAutocmd(<f-args>)
+command! -bar -nargs=+ -complete=event SpotBugsRemoveBufferAutocmd
+    \ call s:RemoveBufferAutocmd(<f-args>)
+
 let &cpo = s:save_cpo
-unlet s:save_cpo
+unlet s:commands s:state s:save_cpo
 
 " vim: set foldmethod=syntax shiftwidth=2 expandtab: