Safety checks for ghc-mod.

lcd047 · lcd047 · commit 2c1c0d0eeb7d · 2013-11-05T20:28:19.000+02:00
diff --git a/syntax_checkers/haskell/ghc-mod.vim b/syntax_checkers/haskell/ghc-mod.vim
@@ -15,13 +15,18 @@ if exists('g:loaded_syntastic_haskell_ghc_mod_checker')
 endif
 let g:loaded_syntastic_haskell_ghc_mod_checker = 1
 
+let s:ghc_mod_new = -1
+
 function! SyntaxCheckers_haskell_ghc_mod_IsAvailable()
-    return executable('ghc-mod')
+    " We need either a Vim version that can handle NULs in system() output,
+    " or a ghc-mod version that has the --boundary option.
+    let s:ghc_mod_new = executable('ghc-mod') ? s:GhcModNew() : -1
+    return (s:ghc_mod_new >= 0) && (v:version >= 704 || s:ghc_mod_new)
 endfunction
 
 function! SyntaxCheckers_haskell_ghc_mod_GetLocList()
     let makeprg = syntastic#makeprg#build({
-        \ 'exe': 'ghc-mod check',
+        \ 'exe': 'ghc-mod check' . (s:ghc_mod_new ? ' --boundary=""' : ''),
         \ 'filetype': 'haskell',
         \ 'subchecker': 'ghc_mod' })
 
@@ -41,6 +46,17 @@ function! SyntaxCheckers_haskell_ghc_mod_GetLocList()
         \ 'postprocess': ['compressWhitespace'] })
 endfunction
 
+function! s:GhcModNew()
+    try
+        let ghc_mod_version = filter(split(system('ghc-mod'), '\n'), 'v:val =~# ''\m^ghc-mod version''')[0]
+        let ret = syntastic#util#versionIsAtLeast(syntastic#util#parseVersion(ghc_mod_version), [2, 1, 2])
+    catch /^Vim\%((\a\+)\)\=:E684/
+        call syntastic#util#error("checker haskell/ghc_mod: can't parse version string (abnormal termination?)")
+        let ret = -1
+    endtry
+    return ret
+endfunction
+
 call g:SyntasticRegistry.CreateAndRegisterChecker({
     \ 'filetype': 'haskell',
     \ 'name': 'ghc_mod'})
