add ale_asm_gcc_executable option (#1138)

* add ale_asm_gcc_executable option
* add Vader tests for asm gcc linter command callbacks

ale_linters/asm/gcc.vim

@@ -1,10 +1,16 @@
 " Author: Lucas Kolstad <lkolstad@uw.edu>
 " Description: gcc linter for asm files
 
-let g:ale_asm_gcc_options = get(g:, 'ale_asm_gcc_options', '-Wall')
+call ale#Set('asm_gcc_executable', 'gcc')
+call ale#Set('asm_gcc_options', '-Wall')
+
+function! ale_linters#asm#gcc#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'asm_gcc_executable')
+endfunction
 
 function! ale_linters#asm#gcc#GetCommand(buffer) abort
-    return 'gcc -x assembler -fsyntax-only '
+    return ale#Escape(ale_linters#asm#gcc#GetExecutable(a:buffer))
+    \    . ' -x assembler -fsyntax-only '
     \    . '-iquote ' . ale#Escape(fnamemodify(bufname(a:buffer), ':p:h'))
     \    . ' ' . ale#Var(a:buffer, 'asm_gcc_options') . ' -'
 endfunction
@@ -27,7 +33,7 @@ endfunction
 call ale#linter#Define('asm', {
 \    'name': 'gcc',
 \    'output_stream': 'stderr',
-\    'executable': 'gcc',
+\    'executable_callback': 'ale_linters#asm#gcc#GetExecutable',
 \    'command_callback': 'ale_linters#asm#gcc#GetCommand',
 \    'callback': 'ale_linters#asm#gcc#Handle',
 \})

doc/ale-asm.txt

@@ -5,6 +5,14 @@ ALE ASM Integration                                           *ale-asm-options*
 ===============================================================================
 gcc                                                               *ale-asm-gcc*
 
+g:ale_asm_gcc_executable                             *g:ale_asm_gcc_executable*
+                                                     *b:ale_asm_gcc_executable*
+  Type: |String|
+  Default: `'gcc'`
+
+This variable can be changed to use a different executable for gcc.
+
+
 g:ale_asm_gcc_options                                   *g:ale_asm_gcc_options*
                                                         *b:ale_asm_gcc_options*
   Type: |String|

test/command_callback/test_asm_gcc_command_callbacks.vader

@@ -0,0 +1,39 @@
+Before:
+  Save g:ale_asm_gcc_executable
+  Save g:ale_asm_gcc_options
+
+  unlet! g:ale_asm_gcc_executable
+  unlet! b:ale_asm_gcc_executable
+  unlet! g:ale_asm_gcc_options
+  unlet! b:ale_asm_gcc_options
+
+  runtime ale_linters/asm/gcc.vim
+
+  let b:command_tail = ' -x assembler -fsyntax-only -iquote'
+  \   . ' ' . ale#Escape(getcwd())
+  \   . ' -Wall -'
+
+After:
+  Restore
+  unlet! b:command_tail
+  unlet! b:ale_asm_gcc_executable
+  unlet! b:ale_asm_gcc_options
+  call ale#linter#Reset()
+
+Execute(The executable should be configurable):
+  AssertEqual 'gcc', ale_linters#asm#gcc#GetExecutable(bufnr(''))
+
+  let b:ale_asm_gcc_executable = 'foobar'
+
+  AssertEqual 'foobar', ale_linters#asm#gcc#GetExecutable(bufnr(''))
+
+Execute(The executable should be used in the command):
+  AssertEqual
+  \ ale#Escape('gcc') . b:command_tail,
+  \ ale_linters#asm#gcc#GetCommand(bufnr(''))
+
+  let b:ale_asm_gcc_executable = 'foobar'
+
+  AssertEqual
+  \ ale#Escape('foobar') . b:command_tail,
+  \ ale_linters#asm#gcc#GetCommand(bufnr(''))