Added clang-tidy for C, too.

A limited number of clang-tidy checks can be used with C, too. I pretty much
copied and refactored the C++ clang-tidy linter, and added some documentation
about C-compatible checks.

README.md

@@ -61,7 +61,7 @@ name. That seems to be the fairest way to arrange this table.
 | Awk | [gawk](https://www.gnu.org/software/gawk/)|
 | Bash | [-n flag](https://www.gnu.org/software/bash/manual/bash.html#index-set), [shellcheck](https://www.shellcheck.net/) |
 | Bourne Shell | [-n flag](http://linux.die.net/man/1/sh), [shellcheck](https://www.shellcheck.net/) |
-| C | [cppcheck](http://cppcheck.sourceforge.net), [gcc](https://gcc.gnu.org/), [clang](http://clang.llvm.org/)|
+| C | [cppcheck](http://cppcheck.sourceforge.net), [gcc](https://gcc.gnu.org/), [clang](http://clang.llvm.org/), [clangtidy](http://clang.llvm.org/extra/clang-tidy/)|
 | C++ (filetype cpp) | [clang](http://clang.llvm.org/), [clangcheck](http://clang.llvm.org/docs/ClangCheck.html), [clangtidy](http://clang.llvm.org/extra/clang-tidy/), [cppcheck](http://cppcheck.sourceforge.net), [cpplint](https://github.com/google/styleguide/tree/gh-pages/cpplint), [gcc](https://gcc.gnu.org/)|
 | C# | [mcs](http://www.mono-project.com/docs/about-mono/languages/csharp/) |
 | Chef | [foodcritic](http://www.foodcritic.io/) |

ale_linters/c/clangtidy.vim

@@ -0,0 +1,107 @@
+" Author: vdeurzen <tim@kompiler.org>, w0rp <devw0rp@gmail.com>,
+" gagbo <gagbobada@gmail.com>, Andrej Radovic <r.andrej@gmail.com>
+" Description: clang-tidy linter for c files
+
+call ale#Set('c_clangtidy_executable', 'clang-tidy')
+" Set this option to check the checks clang-tidy will apply.
+" The number of checks that can be applied to C files is limited in contrast to
+" C++
+"
+" Here is an incomplete list of C-compatible checks for clang-tidy version 6:
+" bugprone-suspicious-memset-usage
+" cert-env33-c
+" cert-err34-c
+" cert-flp30-c
+" google-runtime-int
+" llvm-header-guard
+" llvm-include-order
+" misc-argument-comment
+" misc-assert-side-effect
+" misc-bool-pointer-implicit-conversion
+" misc-definitions-in-headers
+" misc-incorrect-roundings
+" misc-macro-parentheses
+" misc-macro-repeated-side-effects
+" misc-misplaced-const
+" misc-misplaced-widening-cast
+" misc-multiple-statement-macro
+" misc-non-copyable-objects
+" misc-redundant-expression
+" misc-sizeof-expression
+" misc-static-assert
+" misc-string-literal-with-embedded-nul
+" misc-suspicious-enum-usage
+" misc-suspicious-missing-comma
+" misc-suspicious-semicolon
+" misc-suspicious-string-compare
+" misc-swapped-arguments
+" modernize-redundant-void-arg
+" modernize-use-bool-literals
+" performance-type-promotion-in-math-fn
+" readability-braces-around-statements
+" readability-else-after-return
+" readability-function-size
+" readability-identifier-naming
+" readability-implicit-bool-cast
+" readability-inconsistent-declaration-parameter-name
+" readability-misleading-indentation
+" readability-misplaced-array-index
+" readability-named-parameter
+" readability-non-const-parameter
+" readability-redundant-control-flow
+" readability-redundant-declaration
+" readability-redundant-function-ptr-dereference
+" readability-simplify-boolean-expr
+
+call ale#Set('c_clangtidy_checks', ['*'])
+" Set this option to manually set some options for clang-tidy.
+" This will disable compile_commands.json detection.
+call ale#Set('c_clangtidy_options', '')
+call ale#Set('c_build_dir', '')
+
+function! ale_linters#c#clangtidy#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'c_clangtidy_executable')
+endfunction
+
+function! s:GetBuildDirectory(buffer) abort
+    " Don't include build directory for header files, as compile_commands.json
+    " files don't consider headers to be translation units, and provide no
+    " commands for compiling header files.
+    if expand('#' . a:buffer) =~# '\v\.(h|hpp)$'
+        return ''
+    endif
+
+    let l:build_dir = ale#Var(a:buffer, 'c_build_dir')
+
+    " c_build_dir has the priority if defined
+    if !empty(l:build_dir)
+        return l:build_dir
+    endif
+
+    return ale#c#FindCompileCommands(a:buffer)
+endfunction
+
+function! ale_linters#c#clangtidy#GetCommand(buffer) abort
+    let l:checks = join(ale#Var(a:buffer, 'c_clangtidy_checks'), ',')
+    let l:build_dir = s:GetBuildDirectory(a:buffer)
+
+    " Get the extra options if we couldn't find a build directory.
+    let l:options = empty(l:build_dir)
+    \   ? ale#Var(a:buffer, 'c_clangtidy_options')
+    \   : ''
+
+    return ale#Escape(ale_linters#c#clangtidy#GetExecutable(a:buffer))
+    \   . (!empty(l:checks) ? ' -checks=' . ale#Escape(l:checks) : '')
+    \   . ' %s'
+    \   . (!empty(l:build_dir) ? ' -p ' . ale#Escape(l:build_dir) : '')
+    \   . (!empty(l:options) ? ' -- ' . l:options : '')
+endfunction
+
+call ale#linter#Define('c', {
+\   'name': 'clangtidy',
+\   'output_stream': 'stdout',
+\   'executable_callback': 'ale_linters#c#clangtidy#GetExecutable',
+\   'command_callback': 'ale_linters#c#clangtidy#GetCommand',
+\   'callback': 'ale#handlers#gcc#HandleGCCFormat',
+\   'lint_file': 1,
+\})

doc/ale-c.txt

@@ -2,6 +2,37 @@
 ALE C Integration                                               *ale-c-options*
 
 
+===============================================================================
+Global Options
+
+g:ale_c_build_dir_names                               *g:ale_c_build_dir_names*
+                                                      *b:ale_c_build_dir_names*
+
+  Type: |List|
+  Default: `['build', 'bin']`
+
+  A list of directory names to be used when searching upwards from cpp
+  files to discover compilation databases with. For directory named `'foo'`,
+  ALE will search for `'foo/compile_commands.json'` in all directories on and above
+  the directory containing the cpp file to find path to compilation database.
+  This feature is useful for the clang tools wrapped around LibTooling (namely
+  here, clang-tidy)
+
+
+g:ale_c_build_dir                                           *g:ale_c_build_dir*
+                                                            *b:ale_c_build_dir*
+
+  Type: |String|
+  Default: `''`
+
+  A path to the directory containing the `compile_commands.json` file to use
+  with c-family linters. Usually setting this option to a non-empty string
+  will override the |g:ale_c_build_dir_names| option to impose a compilation
+  database (it can be useful if multiple builds are in multiple build
+  subdirectories in the project tree).
+  This feature is also most useful for the clang tools linters, wrapped
+  aroung LibTooling (namely clang-tidy here)
+
 ===============================================================================
 clang                                                             *ale-c-clang*
 
@@ -21,6 +52,104 @@ g:ale_c_clang_options                                   *g:ale_c_clang_options*
   This variable can be changed to modify flags given to clang.
 
 
+===============================================================================
+clangtidy                                                   *ale-c-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.
+Therefore, `clang-tidy` linter reads the options |g:ale_c_build_dir| and
+|g:ale_c_build_dir_names|. Also, setting |g:ale_c_build_dir| actually
+overrides |g:ale_c_build_dir_names|.
+
+
+g:ale_c_clangtidy_checks                             *g:ale_c_clangtidy_checks*
+                                                     *b:ale_c_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.
+
+  Not all of clangtidy checks are applicable for C. You should consult the
+  clang documentation for an up-to-date list of compatible checks.
+
+  Here's an (incomplete) list of C-compatible checks, for clang-tidy version 6:
+    bugprone-suspicious-memset-usage
+    cert-env33-c
+    cert-err34-c
+    cert-flp30-c
+    google-runtime-int
+    llvm-header-guard
+    llvm-include-order
+    misc-argument-comment
+    misc-assert-side-effect
+    misc-bool-pointer-implicit-conversion
+    misc-definitions-in-headers
+    misc-incorrect-roundings
+    misc-macro-parentheses
+    misc-macro-repeated-side-effects
+    misc-misplaced-const
+    misc-misplaced-widening-cast
+    misc-multiple-statement-macro
+    misc-non-copyable-objects
+    misc-redundant-expression
+    misc-sizeof-expression
+    misc-static-assert
+    misc-string-literal-with-embedded-nul
+    misc-suspicious-enum-usage
+    misc-suspicious-missing-comma
+    misc-suspicious-semicolon
+    misc-suspicious-string-compare
+    misc-swapped-arguments
+    modernize-redundant-void-arg
+    modernize-use-bool-literals
+    performance-type-promotion-in-math-fn
+    readability-braces-around-statements
+    readability-else-after-return
+    readability-function-size
+    readability-identifier-naming
+    readability-implicit-bool-cast
+    readability-inconsistent-declaration-parameter-name
+    readability-misleading-indentation
+    readability-misplaced-array-index
+    readability-named-parameter
+    readability-non-const-parameter
+    readability-redundant-control-flow
+    readability-redundant-declaration
+    readability-redundant-function-ptr-dereference
+    readability-simplify-boolean-expr
+
+
+g:ale_c_clangtidy_executable                 *g:ale_c_clangtidy_executable*
+                                               *b:ale_c_clangtidy_executable*
+  Type: |String|
+  Default: `'clang-tidy'`
+
+  This variable can be changed to use a different executable for clangtidy.
+
+
+g:ale_c_clangtidy_options                       *g:ale_c_clangtidy_options*
+                                                  *b:ale_c_clangtidy_options*
+  Type: |String|
+  Default: `''`
+
+  This variable can be changed to modify flags given to clang-tidy.
+
+  - Setting this variable to a non-empty string,
+  - and working in a buffer where no compilation database is found using
+    |g:ale_c_build_dir_names| or |g:ale_c_build_dir|,
+  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, and no `compile_commands.json` file is in one
+  of the |g:ale_c_build_dir_names| directories of the project tree.
+
+
 ===============================================================================
 cppcheck                                                       *ale-c-cppcheck*
 

doc/ale.txt

@@ -16,6 +16,7 @@ CONTENTS                                                         *ale-contents*
       gcc.................................|ale-asm-gcc|
     c.....................................|ale-c-options|
       clang...............................|ale-c-clang|
+      clangtidy...........................|ale-c-clangtidy|
       cppcheck............................|ale-c-cppcheck|
       gcc.................................|ale-c-gcc|
     chef..................................|ale-chef-options|