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This is a short introduction to the basics of ClangCheck tool.


ClangCheck is a small wrapper around LibTooling which can be used to do basic error checking and AST dumping.

The available functions and options for clang-check can be found by the help option:

clang-check --help

Let us try the features with the hello world program in C.

cat << EOF > hello_world.c
#include <stdio.h>

#define STR "Hello World"

/* Multi-line Comment - 
 * Starting main function here
int main()
  // Printing Hello World
  printf("%s\n", STR);
  return 0;

A.1 –ast-dump/–ast-print

clang-check can be used to dump out the AST.

clang-check --ast-dump hello_world.c --

The ‘–-’ at the end is important as it prevents clang-check from searching for a compilation database.

Or clang-check can pretty-print the AST.

clang-check --ast-print hello_world.c --

A.2 –ast-list

clang-check can Build ASTs and print the list of declaration node qualified names.

clang-check --ast-list hello_world.c --

A.3 –ast-dump-filter

Use with -ast-dump or -ast-print to dump/print only AST declaration nodes having a certain substring in a qualified name. Use -ast-list to list all filterable declaration node names.

We can dump out only the main function of the Hello World program.

clang-check --ast-dump --ast-dump-filter=main hello_world.c --

We can use –ast-list to find a specific funciton name. Then use –ast-dump-filter to find out the AST of this funciton.

clang-check --ast-list hello_world.c -- | grep printf
clang-check --ast-dump --ast-dump-filter=fprintf hello_world.c --