Why is my Vim plugin ALE valid for C files, but not for C++?

[zhangyu1131]

I use vim-plug to manage plugins.

This is my .vimrc.

call plug#begin('~/.vim/plugged')
Plug 'dense-analysis/ale'
call plug#end()
……
let g:ale_linters_explicit = 1
let g:ale_linters = {
  \   'csh': ['shell'],
  \   'zsh': ['shell'],
  \   'go': ['gofmt', 'golint'],
  \   'python': ['flake8', 'mypy', 'pylint'],
  \   'c': ['gcc', 'cppcheck'],
  \   'c++': ['g++'],
  \   'text': [],
  \}
let g:ale_completion_delay = 500
let g:ale_echo_delay = 20
let g:ale_lint_delay = 500
let g:ale_echo_msg_format = '[%linter%] %code: %%s'
let g:ale_lint_on_text_changed = 'normal'
let g:ale_lint_on_insert_leave = 1
let g:airline#extensions#ale#enabled = 1
let g:ale_c_gcc_options = '-Wall -O2 -std=c99'
let g:ale_cpp_gcc_options = '-Wall -O2 -std=c++11'
let g:ale_c_cppcheck_options = ''
let g:ale_cpp_cppcheck_options = ''

When I open c file, it works well.

But when I open c++ file, it doesn't work anymore!

I don't know this is why and I use ALEInfo, then I see there is no command history in c++ file.

  Command History:

But in c file, there are some commands.

  Command History:
(executable check - success) clang
(finished - exit code 1) ['/bin/bash', '-c', '''clang'' -S -x c -o /dev/null -iquote ''/home/mydir'' -std=c11 -Wall - < ''/tmp/v6wfTrO/1/test.c''']
<<<OUTPUT STARTS>>>
<stdin>:3:1: error: unknown type name 'dfs'
dfs
^
<stdin>:5:1: error: expected identifier or '('
int main() {
^
2 errors generated.
<<<OUTPUT ENDS>>>
(executable check - failure) cppcheck

Is there any problem I didn't realize?