cli: publish the --clang option

cli/cmdlineparser.cpp

@@ -973,6 +973,7 @@ void CmdLineParser::printHelp()
               "                         analysis is disabled by this flag.\n"
               "    --check-library      Show information messages when library files have\n"
               "                         incomplete info.\n"
+              "    --clang              Import Clang AST\n"
               "    --config-exclude=<dir>\n"
               "                         Path (prefix) to be excluded from configuration\n"
               "                         checking. Preprocessor configurations defined in\n"

man/manual.md

@@ -108,6 +108,14 @@ This option is only valid when supplying an input directory. To ignore multiple
 
     cppcheck -isrc/b -isrc/c
 
+### Clang parser
+
+By default Cppcheck uses an internal C/C++ parser. However it is possible to use the Clang parser instead.
+
+Install `clang`. Then use Cppcheck option `--clang`.
+
+Technically, Cppcheck will execute `clang` with its `-ast-dump` option. The Clang output is then imported and converted into our normal Cppcheck format. And then normal Cppcheck analysis is performed on that.
+
 ## Severities
 
 The possible severities for messages are: