/* This plugin exercises diagnostic_metadata.  */

#include "gcc-plugin.h"
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "stringpool.h"
#include "toplev.h"
#include "basic-block.h"
#include "hash-table.h"
#include "vec.h"
#include "ggc.h"
#include "basic-block.h"
#include "tree-ssa-alias.h"
#include "internal-fn.h"
#include "gimple.h"
#include "gimple-iterator.h"
#include "gimple-fold.h"
#include "tree-eh.h"
#include "gimple-expr.h"
#include "is-a.h"
#include "tree.h"
#include "tree-pass.h"
#include "intl.h"
#include "plugin-version.h"
#include "diagnostic.h"
#include "context.h"
#include "gcc-rich-location.h"
#include "diagnostic-metadata.h"

int plugin_is_GPL_compatible;

const pass_data pass_data_test_metadata =
{
  GIMPLE_PASS, /* type */
  "test_metadata", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  PROP_ssa, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  0, /* todo_flags_finish */
};

class pass_test_metadata : public gimple_opt_pass
{
public:
  pass_test_metadata(gcc::context *ctxt)
    : gimple_opt_pass(pass_data_test_metadata, ctxt)
  {}

  /* opt_pass methods: */
  bool gate (function *) { return true; }
  virtual unsigned int execute (function *);

}; // class pass_test_metadata

/* Determine if STMT is a call with NUM_ARGS arguments to a function
   named FUNCNAME.
   If so, return STMT as a gcall *.  Otherwise return NULL.  */

static gcall *
check_for_named_call (gimple *stmt,
		      const char *funcname, unsigned int num_args)
{
  gcc_assert (funcname);

  gcall *call = dyn_cast <gcall *> (stmt);
  if (!call)
    return NULL;

  tree fndecl = gimple_call_fndecl (call);
  if (!fndecl)
    return NULL;

  if (strcmp (IDENTIFIER_POINTER (DECL_NAME (fndecl)), funcname))
    return NULL;

  if (gimple_call_num_args (call) != num_args)
    {
      error_at (stmt->location, "expected number of args: %i (got %i)",
		num_args, gimple_call_num_args (call));
      return NULL;
    }

  return call;
}

/* Exercise diagnostic_metadata.  */

unsigned int
pass_test_metadata::execute (function *fun)
{
  gimple_stmt_iterator gsi;
  basic_block bb;

  FOR_EACH_BB_FN (bb, fun)
    for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
      {
	gimple *stmt = gsi_stmt (gsi);

	/* Example of CWE: complain about uses of gets.  */
	if (gcall *call = check_for_named_call (stmt, "gets", 1))
	  {
	    gcc_rich_location richloc (gimple_location (call));
	    diagnostic_metadata m;

	    /* CWE-242: Use of Inherently Dangerous Function.  */
	    m.add_cwe (242);

	    /* Example of a diagnostic_metadata::rule.  */
	    diagnostic_metadata::precanned_rule
	      test_rule ("STR34-C", "https://example.com/");
	    m.add_rule (test_rule);

	    warning_meta (&richloc, m, 0,
			  "never use %qs", "gets");
	  }
      }

  return 0;
}

int
plugin_init (struct plugin_name_args *plugin_info,
	     struct plugin_gcc_version *version)
{
  struct register_pass_info pass_info;
  const char *plugin_name = plugin_info->base_name;
  int argc = plugin_info->argc;
  struct plugin_argument *argv = plugin_info->argv;

  if (!plugin_default_version_check (version, &gcc_version))
    return 1;

  pass_info.pass = new pass_test_metadata (g);
  pass_info.reference_pass_name = "ssa";
  pass_info.ref_pass_instance_number = 1;
  pass_info.pos_op = PASS_POS_INSERT_AFTER;
  register_callback (plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
		     &pass_info);

  return 0;
}