scripts/unifdef.c

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

File Facts

System
Linux kernel
Corpus path
scripts/unifdef.c
Extension
.c
Size
35672 bytes
Lines
1226
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 op {
		const char *str;
		Linetype (*fn)(int *, Linetype, int, Linetype, int);
	} op[5];
} eval_ops[] = {
	{ eval_table, { { "||", op_or } } },
	{ eval_table, { { "&&", op_and } } },
	{ eval_table, { { "==", op_eq },
			{ "!=", op_ne } } },
	{ eval_unary, { { "<=", op_le },
			{ ">=", op_ge },
			{ "<", op_lt },
			{ ">", op_gt } } }
};

/*
 * Function for evaluating the innermost parts of expressions,
 * viz. !expr (expr) number defined(symbol) symbol
 * We reset the constexpression flag in the last two cases.
 */
static Linetype
eval_unary(const struct ops *ops, int *valp, const char **cpp)
{
	const char *cp;
	char *ep;
	int sym;
	bool defparen;
	Linetype lt;

	cp = skipcomment(*cpp);
	if (*cp == '!') {
		debug("eval%d !", ops - eval_ops);
		cp++;
		lt = eval_unary(ops, valp, &cp);
		if (lt == LT_ERROR)
			return (LT_ERROR);
		if (lt != LT_IF) {
			*valp = !*valp;
			lt = *valp ? LT_TRUE : LT_FALSE;
		}
	} else if (*cp == '(') {
		cp++;
		debug("eval%d (", ops - eval_ops);
		lt = eval_table(eval_ops, valp, &cp);
		if (lt == LT_ERROR)
			return (LT_ERROR);
		cp = skipcomment(cp);
		if (*cp++ != ')')
			return (LT_ERROR);
	} else if (isdigit((unsigned char)*cp)) {
		debug("eval%d number", ops - eval_ops);
		*valp = strtol(cp, &ep, 0);
		if (ep == cp)
			return (LT_ERROR);
		lt = *valp ? LT_TRUE : LT_FALSE;
		cp = skipsym(cp);
	} else if (strncmp(cp, "defined", 7) == 0 && endsym(cp[7])) {
		cp = skipcomment(cp+7);
		debug("eval%d defined", ops - eval_ops);
		if (*cp == '(') {
			cp = skipcomment(cp+1);
			defparen = true;
		} else {
			defparen = false;
		}
		sym = findsym(cp);
		if (sym < 0) {
			lt = LT_IF;
		} else {
			*valp = (value[sym] != NULL);
			lt = *valp ? LT_TRUE : LT_FALSE;
		}
		cp = skipsym(cp);
		cp = skipcomment(cp);
		if (defparen && *cp++ != ')')
			return (LT_ERROR);
		constexpression = false;
	} else if (!endsym(*cp)) {
		debug("eval%d symbol", ops - eval_ops);
		sym = findsym(cp);
		cp = skipsym(cp);
		if (sym < 0) {
			lt = LT_IF;
			cp = skipargs(cp);
		} else if (value[sym] == NULL) {
			*valp = 0;
			lt = LT_FALSE;
		} else {
			*valp = strtol(value[sym], &ep, 0);
			if (*ep != '\0' || ep == value[sym])

Annotation

Implementation Notes