I have clangd installed. How do I connect it with ALE?

[ubaldot]

When I use commands like :ALEGoToDefinition, :ALEComplete, etc, nothing seems to happen.
I am suspicious that ALE is simply not connected to clangd (in-spite clang-tidy works amazingly).
Inspection of :help ale-lint-language-server suggest to add the following to my _vimrc.

call ale#linter#Define('c', {
  \   'name': 'clangd',
  \   'lsp': 'stdio',
  \   'executable': 'C:\Program Files (x86)\LLVM\bin',
  \   'command': '%e run',
  \   'project_root':'C:\MyProject',
  \})

But when I run :ALEGoToDefinition of :ALEComplete nothing happens.
I have a compile_commands.json file and <C-x> <C-o> works well, but ALE.

My Vim:

VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Sep 21 2021 22:13:38)
MS-Windows 32-bit console version
Included patches: 1-3452
Compiled by appveyor@APPVYR-WIN

My ALEInfo

 Current Filetype: c
Available Linters: ['cc', 'ccls', 'clangd', 'clangtidy', 'cppcheck', 'cquery', 'flawfinder']
   Linter Aliases:
'cc' -> ['gcc', 'clang']
  Enabled Linters: ['clangtidy']
  Ignored Linters: []
 Suggested Fixers: 
  'astyle' - Fix C/C++ with astyle.
  'clang-format' - Fix C/C++ and cuda files with clang-format.
  'clangtidy' - Fix C/C++ and ObjectiveC files with clang-tidy.
  'remove_trailing_lines' - Remove all blank lines at the end of a file.
  'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
  'uncrustify' - Fix C, C++, C#, ObjectiveC, ObjectiveC++, D, Java, Pawn, and VALA files with uncrustify.
 Linter Variables:

let g:ale_c_always_make = 0
let g:ale_c_build_dir = ''
let g:ale_c_build_dir_names = ['build', 'bin']
let g:ale_c_clangtidy_checks = ['*']
let g:ale_c_clangtidy_executable = 'clang-tidy'
let g:ale_c_clangtidy_extra_options = '--extra-arg=-I --extra-arg=C:\Devtools\Install\Cygwin\3.0.7\usr\include --extra-arg=-I --extra-arg=C:\PE_Builds\sw-ecu\BSW\_out\P_AMTG_MC_TEA2P\bin\all_inc'
let g:ale_c_clangtidy_options = ''
let g:ale_c_parse_compile_commands = 1
let g:ale_c_parse_makefile = 0
 Global Variables:

let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = 0
let g:ale_command_wrapper = ''
let g:ale_completion_delay = 100
let g:ale_completion_enabled = 0
let g:ale_completion_max_suggestions = 50
let g:ale_disable_lsp = 0
let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%code: %%s'
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_fix_on_save = 0
let g:ale_fixers = {'c': ['astyle', 'clangtidy', 'remove_trailing_lines', 'trim_whitespace']}
let g:ale_history_enabled = 1
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_filetype_changed = 1
let g:ale_lint_on_insert_leave = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 'normal'
let g:ale_linter_aliases = {}
let g:ale_linters = {'c': ['clangtidy'], 'python': ['flake8']}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {}
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
let g:ale_max_buffer_history_size = 20
let g:ale_max_signs = -1
let g:ale_maximum_file_size = v:null
let g:ale_open_list = 0
let g:ale_pattern_options = v:null
let g:ale_pattern_options_enabled = v:null
let g:ale_root = {}
let g:ale_set_balloons = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '>>'
let g:ale_sign_info = '--'
let g:ale_sign_offset = 1000000
let g:ale_sign_style_error = '>>'
let g:ale_sign_style_warning = '--'
let g:ale_sign_warning = '--'
let g:ale_sign_highlight_linenrs = 0
let g:ale_statusline_format = v:null
let g:ale_type_map = {}
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 0
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
  Command History:

(executable check - success) clang-tidy
(finished - exit code -1073741795) 'cmd /s/c "clang-tidy -checks=* "--extra-arg=-I --extra-arg=C:\Cygwin\3.0.7\usr\include --extra-arg=-I --extra-arg=C:\MyProject\_out\all_inc" C:\MyProject\src\MySource.c -p C:\MyProject"'

<<<NO OUTPUT RETURNED>>>

(started) 'cmd /s/c "clang-tidy -checks=* "--extra-arg=-I --extra-arg=C:\Cygwin\3.0.7\usr\include --extra-arg=-I --extra-arg=C:\MyProject\_out\all_inc" C:\MyProject\src\MySource.c  -p C:\MyProject"'

[hsanson]

The clangd is already defined in ALE, you do not need to define it again in your configuration.

First add clangd to your list of enabled linters. Currently you only have defined clangtidy for C files (see :h g:ale_linters):

let g:ale_linters = {'c': ['clangtidy'], 'python': ['flake8']}

ALE should be able to find the clangd binary on its own but you can tell it where to find it if it doesn't:

let g:ale_c_clangd_executable = '/path/to/bin/clangd'

You can also set options that ALE will use when invoking clangd. See :h ale-c-clangd for additonal details.

Finally make sure vim/neovim current folder is a C project folder. ALE won't start the language server if it cannot find the project root. The project root will be the path where the compile_commands.json file is located.

[ubaldot]

Perfect!
Now clangd is recognized well. Many thanks!

However, :ALEGoToDefinition and :ALEFindReferences seems to partially work.
More precisely, they can find definitions and references only among opened buffers.
For example, if MyFile1.c calls foo() and foo() is defined in MyFile2.c (contained in the same folder), then :ALEGoToDefinition will not find foo() if MyFile2.c is not opened.

Also, :ALEComplete does not seem to work super good.
If I have a user-defined function (say cdd_foo()) and then I type cdd_ and then I call :ALEComplete nothing happens if cdd_foo() is declared in a file not located in the same folder.
Otherwise, the completion seems to work for all those functions whose declaration is "in-folder-scope" (for example in some .h file located in the same folder of my currently opened .c file).
If it normal? How to fix it?
Or maybe this is the due to the double quotation mark issue that I have?
More precisely, from my :ALEInfo of above you can see that clang-tidy delimits the various --extra-arg with a double quotation mark, " i.e.

(finished - exit code -1073741795) 'cmd /s/c "clang-tidy -checks=* "--extra-arg=-I --extra-arg=C:\Cygwin\3.0.7\usr\include --extra-arg=-I --extra-arg=C:\MyProject\_out\all_inc" C:\MyProject\src\MySource.c -p C:\MyProject"'

This leads to several linting errors (and perhaps to the fact that I cannot find functions defined in some other file, see above).
I tried to run the same command from the Powershell without any quotation marks, i.e.

clang-tidy -checks=* --extra-arg=-I --extra-arg=C:\Cygwin\3.0.7\usr\include --extra-arg=-I --extra-arg=C:\MyProject\_out\all_inc C:\MyProject\src\MySource.c -p C:\MyProject

and it works correctly.
I have raised a bug for it but it seems to have been forgotten :/

[hsanson]

Very difficult for me to help you here. I do not use clangd, last time I did C was 10 years ago, and I do not have any Windows machines around me.

Would recommend you create a small "hello world" C project that presents the same problems and share it in a git repo. Maybe someone with similar environment as you can help debug what may be the problem.

[ubaldot]

No problem at all! :)
You already hugely helped me!
Many thanks!

Regarding the jump to definition/declaration/implementation/... I have found this:

#2550

Regarding the double quotation mark added in the --extra-arg I will wait.
In the meantime I will run clang-tidy from Powershell to figure what is going on with my code :)