Fix #410 - Use compile_commands.json files for clang-tidy, and check files on disk instead

ale_linters/cpp/clangtidy.vim

@@ -1,12 +1,24 @@
 " Author: vdeurzen <tim@kompiler.org>, w0rp <devw0rp@gmail.com>
 " Description: clang-tidy linter for cpp files
 
-" Set this option to change the clang-tidy options for warnings for C.
-let g:ale_cpp_clangtidy_options =
-\   get(g:, 'ale_cpp_clangtidy_options', '-std=c++14 -Wall')
+" Set this option to check the checks clang-tidy will apply.
+let g:ale_cpp_clangtidy_checks = get(g:, 'ale_cpp_clangtidy_checks', ['*'])
+
+" Set this option to manually set some options for clang-tidy.
+" This will disable compile_commands.json detection.
+let g:ale_cpp_clangtidy_options = get(g:, 'ale_cpp_clangtidy_options', '')
 
 function! ale_linters#cpp#clangtidy#GetCommand(buffer) abort
-    return 'clang-tidy %t -- ' . ale#Var(a:buffer, 'cpp_clangtidy_options')
+    let l:check_list = ale#Var(a:buffer, 'cpp_clangtidy_checks')
+    let l:check_option = !empty(l:check_list)
+    \   ? '-checks=' . shellescape(join(l:check_list, ',')) . ' '
+    \   : ''
+    let l:user_options = ale#Var(a:buffer, 'cpp_clangtidy_options')
+    let l:extra_options = !empty(l:user_options)
+    \   ? ' -- ' . l:user_options
+    \   : ''
+
+    return 'clang-tidy ' . l:check_option . '%s' . l:extra_options
 endfunction
 
 call ale#linter#Define('cpp', {
@@ -15,4 +27,5 @@ call ale#linter#Define('cpp', {
 \   'executable': 'clang-tidy',
 \   'command_callback': 'ale_linters#cpp#clangtidy#GetCommand',
 \   'callback': 'ale#handlers#gcc#HandleGCCFormat',
+\   'lint_file': 1,
 \})

doc/ale-cpp.txt

@@ -16,12 +16,35 @@ g:ale_cpp_clang_options                               *g:ale_cpp_clang_options*
 -------------------------------------------------------------------------------
 clangtidy                                                   *ale-cpp-clangtidy*
 
+`clang-tidy` will be run only when files are saved to disk, so that
+`compile_commands.json` files can be used. It is recommended to use this
+linter in combination with `compile_commands.json` files.
+
+
+g:ale_cpp_clangtidy_checks                         *g:ale_cpp_clangtidy_checks*
+                                                   *b:ale_cpp_clangtidy_checks*
+  Type: |List|
+  Default: `['*']`
+
+  The checks to enable for clang-tidy with the `-checks` argument.
+
+  All options will be joined with commas, and escaped appropriately for
+  the shell. The `-checks` flag can be removed entirely by setting this
+  option to an empty List.
+
+
 g:ale_cpp_clangtidy_options                       *g:ale_cpp_clangtidy_options*
                                                   *b:ale_cpp_clangtidy_options*
   Type: |String|
-  Default: `'-std=c++14 -Wall'`
+  Default: `''`
 
-  This variable can be changed to modify flags given to clangtidy.
+  This variable can be changed to modify flags given to clang-tidy.
+
+  Setting this variable to a non-empty string will cause the `--` argument
+  to be passed to `clang-tidy`, which will mean that detection of
+  `compile_commands.json` files for compile command databases will be
+  disabled. Only set this option if you want to control compiler flags
+  entirely manually.
 
 
 -------------------------------------------------------------------------------

test/command_callback/test_clang_tidy_command_callback.vader

@@ -0,0 +1,31 @@
+Before:
+  Save g:ale_cpp_clangtidy_checks
+  Save g:ale_cpp_clangtidy_options
+  runtime ale_linters/cpp/clangtidy.vim
+
+After:
+  Restore
+  call ale#linter#Reset()
+
+Execute(The clangtidy command default should be correct):
+  AssertEqual
+  \ 'clang-tidy -checks=''*'' %s',
+  \ ale_linters#cpp#clangtidy#GetCommand(bufnr(''))
+
+Execute(You should be able to remove the -checks option for clang-tidy):
+  let g:ale_cpp_clangtidy_checks = []
+  AssertEqual
+  \ 'clang-tidy %s',
+  \ ale_linters#cpp#clangtidy#GetCommand(bufnr(''))
+
+Execute(You should be able to set other checks for clang-tidy):
+  let g:ale_cpp_clangtidy_checks = ['-*', 'clang-analyzer-*']
+  AssertEqual
+  \ 'clang-tidy -checks=''-*,clang-analyzer-*'' %s',
+  \ ale_linters#cpp#clangtidy#GetCommand(bufnr(''))
+
+Execute(You should be able to manually set compiler flags for clang-tidy):
+  let g:ale_cpp_clangtidy_options = '-Wall'
+  AssertEqual
+  \ 'clang-tidy -checks=''*'' %s -- -Wall',
+  \ ale_linters#cpp#clangtidy#GetCommand(bufnr(''))