scripts/kconfig/symbol.c

Source file repositories/reference/linux-study-clean/scripts/kconfig/symbol.c

File Facts

System
Linux kernel
Corpus path
scripts/kconfig/symbol.c
Extension
.c
Size
29701 bytes
Lines
1367
Domain
Support Tooling And Documentation
Bucket
scripts
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct sym_match {
	struct symbol	*sym;
	off_t		so, eo;
};

/* Compare matched symbols as thus:
 * - first, symbols that match exactly
 * - then, alphabetical sort
 */
static int sym_rel_comp(const void *sym1, const void *sym2)
{
	const struct sym_match *s1 = sym1;
	const struct sym_match *s2 = sym2;
	int exact1, exact2;

	/* Exact match:
	 * - if matched length on symbol s1 is the length of that symbol,
	 *   then this symbol should come first;
	 * - if matched length on symbol s2 is the length of that symbol,
	 *   then this symbol should come first.
	 * Note: since the search can be a regexp, both symbols may match
	 * exactly; if this is the case, we can't decide which comes first,
	 * and we fallback to sorting alphabetically.
	 */
	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
	if (exact1 && !exact2)
		return -1;
	if (!exact1 && exact2)
		return 1;

	/* As a fallback, sort symbols alphabetically */
	return strcmp(s1->sym->name, s2->sym->name);
}

struct symbol **sym_re_search(const char *pattern)
{
	struct symbol *sym, **sym_arr = NULL;
	struct sym_match *sym_match_arr = NULL;
	int i, cnt, size;
	regex_t re;
	regmatch_t match[1];

	cnt = size = 0;
	/* Skip if empty */
	if (strlen(pattern) == 0)
		return NULL;
	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
		return NULL;

	for_all_symbols(sym) {
		if (sym->flags & SYMBOL_CONST || !sym->name)
			continue;
		if (regexec(&re, sym->name, 1, match, 0))
			continue;
		if (cnt >= size) {
			void *tmp;
			size += 16;
			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
			if (!tmp)
				goto sym_re_search_free;
			sym_match_arr = tmp;
		}
		sym_calc_value(sym);
		/* As regexec returned 0, we know we have a match, so
		 * we can use match[0].rm_[se]o without further checks
		 */
		sym_match_arr[cnt].so = match[0].rm_so;
		sym_match_arr[cnt].eo = match[0].rm_eo;
		sym_match_arr[cnt++].sym = sym;
	}
	if (sym_match_arr) {
		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
		if (!sym_arr)
			goto sym_re_search_free;
		for (i = 0; i < cnt; i++)
			sym_arr[i] = sym_match_arr[i].sym;
		sym_arr[cnt] = NULL;
	}
sym_re_search_free:
	/* sym_match_arr can be NULL if no match, but free(NULL) is OK */
	free(sym_match_arr);
	regfree(&re);

	return sym_arr;
}

/*
 * When we check for recursive dependencies we use a stack to save

Annotation

Implementation Notes