/*
  SPDX-License-Identifier: GPL-2.0-only

  Copyright (C) 2006 Mandriva Conectiva S.A.
  Copyright (C) 2006 Arnaldo Carvalho de Melo <acme@mandriva.com>
*/

#include <assert.h>
#include <dwarf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "dwarves.h"
#include "dutil.h"

static void refcnt_tag(struct tag *tag, const struct cu *cu);

static void refcnt_member(struct class_member *member, const struct cu *cu)
{
	if (member->visited)
		return;
	member->visited = 1;
	if (member->tag.type != 0) { /* if not void */
		struct tag *type = cu__type(cu, member->tag.type);
		if (type != NULL)
			refcnt_tag(type, cu);
	}
}

static void refcnt_parameter(const struct parameter *parameter,
			     const struct cu *cu)
{
	if (parameter->tag.type != 0) { /* if not void */
		struct tag *type = cu__type(cu, parameter->tag.type);
		if (type != NULL)
			refcnt_tag(type, cu);
	}
}

static void refcnt_variable(const struct variable *variable,
			    const struct cu *cu)
{
	if (variable->ip.tag.type != 0) { /* if not void */
		struct tag *type = cu__type(cu, variable->ip.tag.type);
		if (type != NULL)
			refcnt_tag(type, cu);
	}
}

static void refcnt_inline_expansion(const struct inline_expansion *exp,
				    const struct cu *cu)
{
	if (exp->ip.tag.type != 0) { /* if not void */
		struct tag *type = cu__function(cu, exp->ip.tag.type);
		if (type != NULL)
			refcnt_tag(type, cu);
	}
}

static void refcnt_tag(struct tag *tag, const struct cu *cu)
{
	struct class_member *member;

	tag->visited = 1;

	if (tag__is_struct(tag) || tag__is_union(tag)) {
		type__for_each_member(tag__type(tag), member)
			refcnt_member(member, cu);
	}
}

static void refcnt_lexblock(const struct lexblock *lexblock, const struct cu *cu)
{
	struct tag *pos;

	list_for_each_entry(pos, &lexblock->tags, node)
		switch (pos->tag) {
		case DW_TAG_variable:
			refcnt_variable(tag__variable(pos), cu);
			break;
		case DW_TAG_inlined_subroutine:
			refcnt_inline_expansion(tag__inline_expansion(pos), cu);
			break;
		case DW_TAG_lexical_block:
			refcnt_lexblock(tag__lexblock(pos), cu);
			break;
		}
}

static void refcnt_function(struct function *function, const struct cu *cu)
{
	struct parameter *parameter;

	function->proto.tag.visited = 1;

	if (function->proto.tag.type != 0) /* if not void */ {
		struct tag *type = cu__type(cu, function->proto.tag.type);
		if (type != NULL)
			refcnt_tag(type, cu);
	}

	list_for_each_entry(parameter, &function->proto.parms, tag.node)
		refcnt_parameter(parameter, cu);

	refcnt_lexblock(&function->lexblock, cu);
}

static int cu_refcnt_iterator(struct cu *cu, void *cookie __maybe_unused)
{
	struct function *pos;
	uint32_t id;

	cu__for_each_function(cu, id, pos)
		refcnt_function(pos, cu);
	return 0;
}

static int lost_iterator(struct tag *tag, struct cu *cu,
			 void *cookie __maybe_unused)
{
	if (!tag->visited && tag__decl_file(tag, cu)) {
		tag__fprintf(tag, cu, NULL, stdout);
		puts(";\n");
	}
	return 0;
}

static int cu_lost_iterator(struct cu *cu, void *cookie)
{
	return cu__for_all_tags(cu, lost_iterator, cookie);
}

int main(int argc __maybe_unused, char *argv[])
{
	int err;
	struct cus *cus = cus__new();

	if (dwarves__init() || cus == NULL) {
		fputs("prefcnt: insufficient memory\n", stderr);
		return EXIT_FAILURE;
	}

	dwarves__resolve_cacheline_size(NULL, 0);

	err = cus__load_files(cus, NULL, argv + 1);
	if (err != 0) {
		cus__fprintf_load_files_err(cus, "prefcnt", argv + 1, err, stderr);
		return EXIT_FAILURE;
	}

	cus__for_each_cu(cus, cu_refcnt_iterator, NULL, NULL);
	cus__for_each_cu(cus, cu_lost_iterator, NULL, NULL);

	return EXIT_SUCCESS;
}