ctf_types.c

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/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only.
 * See the file usr/src/LICENSING.NOTICE in this distribution or
 * http://www.opensolaris.org/license/ for details.
 */

#pragma ident	"@(#)ctf_types.c	1.6	03/09/02 SMI"

#include <sys/sysmacros.h>
#include <ctf_impl.h>

ssize_t
ctf_get_ctt_size(const ctf_file_t *fp, const ctf_type_t *tp, ssize_t *sizep,
    ssize_t *incrementp)
{
	ssize_t size, increment;

	if (fp->ctf_version > CTF_VERSION_1 &&
	    tp->ctt_size == CTF_LSIZE_SENT) {
		size = CTF_TYPE_LSIZE(tp);
		increment = sizeof (ctf_type_t);
	} else {
		size = tp->ctt_size;
		increment = sizeof (ctf_stype_t);
	}

	if (sizep)
		*sizep = size;
	if (incrementp)
		*incrementp = increment;

	return (size);
}

/*
 * Iterate over the members of a STRUCT or UNION.  We pass the name, member
 * type, and offset of each member to the specified callback function.
 */
int
ctf_member_iter(ctf_file_t *fp, ctf_id_t type, ctf_member_f *func, void *arg)
{
	ctf_file_t *ofp = fp;
	const ctf_type_t *tp;
	ssize_t size, increment;
	uint_t kind, n;
	int rc;

	if ((type = ctf_type_resolve(fp, type)) == CTF_ERR)
		return (CTF_ERR); /* errno is set for us */

	if ((tp = ctf_lookup_by_id(&fp, type)) == NULL)
		return (CTF_ERR); /* errno is set for us */

	(void) ctf_get_ctt_size(fp, tp, &size, &increment);
	kind = LCTF_INFO_KIND(fp, tp->ctt_info);

	if (kind != CTF_K_STRUCT && kind != CTF_K_UNION)
		return (ctf_set_errno(ofp, ECTF_NOTSOU));

	if (fp->ctf_version == CTF_VERSION_1 || size < CTF_LSTRUCT_THRESH) {
		const ctf_member_t *mp = (const ctf_member_t *)
		    ((uintptr_t)tp + increment);

		for (n = LCTF_INFO_VLEN(fp, tp->ctt_info); n != 0; n--, mp++) {
			const char *name = ctf_strptr(fp, mp->ctm_name);
			if ((rc = func(name, mp->ctm_type, mp->ctm_offset,
			    arg)) != 0)
				return (rc);
		}

	} else {
		const ctf_lmember_t *lmp = (const ctf_lmember_t *)
		    ((uintptr_t)tp + increment);

		for (n = LCTF_INFO_VLEN(fp, tp->ctt_info); n != 0; n--, lmp++) {
			const char *name = ctf_strptr(fp, lmp->ctlm_name);
			if ((rc = func(name, lmp->ctlm_type,
			    (ulong_t)CTF_LMEM_OFFSET(lmp), arg)) != 0)
				return (rc);
		}
	}

	return (0);
}

/*
 * Iterate over the members of an ENUM.  We pass the string name and associated
 * integer value of each enum element to the specified callback function.
 */
int
ctf_enum_iter(ctf_file_t *fp, ctf_id_t type, ctf_enum_f *func, void *arg)
{
	ctf_file_t *ofp = fp;
	const ctf_type_t *tp;
	const ctf_enum_t *ep;
	ssize_t increment;
	uint_t n;
	int rc;

	if ((type = ctf_type_resolve(fp, type)) == CTF_ERR)
		return (CTF_ERR); /* errno is set for us */

	if ((tp = ctf_lookup_by_id(&fp, type)) == NULL)
		return (CTF_ERR); /* errno is set for us */

	if (LCTF_INFO_KIND(fp, tp->ctt_info) != CTF_K_ENUM)
		return (ctf_set_errno(ofp, ECTF_NOTENUM));

	(void) ctf_get_ctt_size(fp, tp, NULL, &increment);

	ep = (const ctf_enum_t *)((uintptr_t)tp + increment);

	for (n = LCTF_INFO_VLEN(fp, tp->ctt_info); n != 0; n--, ep++) {
		const char *name = ctf_strptr(fp, ep->cte_name);
		if ((rc = func(name, ep->cte_value, arg)) != 0)
			return (rc);
	}

	return (0);
}

/*
 * Iterate over every root (user-visible) type in the given CTF container.
 * We pass the type ID of each type to the specified callback function.
 */
int
ctf_type_iter(ctf_file_t *fp, ctf_type_f *func, void *arg)
{
	ctf_id_t id, max = fp->ctf_typemax;
	int rc, child = (fp->ctf_flags & LCTF_CHILD);

	for (id = 1; id <= max; id++) {
		const ctf_type_t *tp = LCTF_INDEX_TO_TYPEPTR(fp, id);
		if (CTF_INFO_ISROOT(tp->ctt_info) &&
		    (rc = func(CTF_INDEX_TO_TYPE(id, child), arg)) != 0)
			return (rc);
	}

	return (0);
}

/*
 * Follow a given type through the graph for TYPEDEF, VOLATILE, CONST, and
 * RESTRICT nodes until we reach a "base" type node.  This is useful when
 * we want to follow a type ID to a node that has members or a size.  To guard
 * against infinite loops, we implement simplified cycle detection and check
 * each link against itself, the previous node, and the topmost node.
 */
ctf_id_t
ctf_type_resolve(ctf_file_t *fp, ctf_id_t type)
{
	ctf_id_t prev = type, otype = type;
	ctf_file_t *ofp = fp;
	const ctf_type_t *tp;

	while ((tp = ctf_lookup_by_id(&fp, type)) != NULL) {
		switch (LCTF_INFO_KIND(fp, tp->ctt_info)) {
		case CTF_K_TYPEDEF:
		case CTF_K_VOLATILE:
		case CTF_K_CONST:
		case CTF_K_RESTRICT:
			if (tp->ctt_type == type || tp->ctt_type == otype ||
			    tp->ctt_type == prev) {
				ctf_dprintf("type %ld cycle detected\n", otype);
				return (ctf_set_errno(ofp, ECTF_CORRUPT));
			}
			prev = type;
			type = tp->ctt_type;
			break;
		default:
			return (type);
		}
	}

	return (CTF_ERR); /* errno is set for us */
}

/*
 * Lookup the given type ID and print a string name for it into buf.  If buf
 * is too small, an appropriate error will be returned to the caller.
 */
char *
ctf_type_name(ctf_file_t *fp, ctf_id_t type, char *buf, size_t len)
{
	ctf_file_t *ofp = fp;
	const ctf_type_t *tp;
	const ctf_array_t *ap;
	const char *name;
	char *p, *q;
	uint_t kind;
	ssize_t size, increment;
	int rlen;

	if (buf == NULL || len == 0) {
		(void) ctf_set_errno(ofp, EINVAL);
		return (NULL);
	}

	buf[0] = '\0'; /* start with empty string */

	for (p = buf, q = buf + len; p < q; p += strlen(p)) {
		if ((tp = ctf_lookup_by_id(&fp, type)) == NULL)
			return (NULL); /* errno is set for us */

		len = (size_t)(q - p); /* bytes remaining in buf */
		name = ctf_strptr(fp, tp->ctt_name);
		kind = LCTF_INFO_KIND(fp, tp->ctt_info);
		(void) ctf_get_ctt_size(fp, tp, &size, &increment);

		if (name[0] != '\0' && (kind == CTF_K_FUNCTION ||
		    kind == CTF_K_POINTER || kind == CTF_K_VOLATILE ||
		    kind == CTF_K_CONST || kind == CTF_K_RESTRICT)) {
			if (snprintf(p, len, "%s", name) >= len)
				goto out;
			return (buf);
		}

		switch (kind) {
		case CTF_K_TYPEDEF:
			if (name[0] == '\0') {
				type = tp->ctt_type;
				break;
			}
			/*FALLTHRU*/
		case CTF_K_INTEGER:
		case CTF_K_FLOAT:
			if (snprintf(p, len, "%s", name) >= len)
				goto out;
			return (buf);

		case CTF_K_ARRAY:
			ap = (const ctf_array_t *)((uintptr_t)tp + increment);

			if (ctf_type_name(fp, ap->cta_contents, p, len) == NULL)
				return (NULL); /* errno is set for us */

			p = buf + strlen(buf);
			len = (size_t)(q - p);

			if (snprintf(p, len, " [%u]", ap->cta_nelems) >= len)
				goto out;

			return (buf);

		case CTF_K_FUNCTION:
		case CTF_K_POINTER:
			if (ctf_type_name(fp, tp->ctt_type, p, len) == NULL)
				return (NULL); /* errno is set for us */

			/*
			 * We assume that all functions are really
			 * pointers to functions.
			 */
			if (kind == CTF_K_POINTER &&
			    ctf_type_kind(fp, tp->ctt_type) == CTF_K_FUNCTION)
				return (buf);

			p = buf + strlen(buf);
			len = (size_t)(q - p);

			if (kind == CTF_K_FUNCTION)
				rlen = snprintf(p, len, " (*)()");
			else if (ctf_type_kind(fp,
			    tp->ctt_type) == CTF_K_POINTER)
				rlen = snprintf(p, len, "*");
			else
				rlen = snprintf(p, len, " *");

			if (rlen >= len)
				goto out;

			return (buf);

		case CTF_K_STRUCT:
		case CTF_K_FORWARD:
			if (snprintf(p, len, "struct %s", name) >= len)
				goto out;
			return (buf);

		case CTF_K_UNION:
			if (snprintf(p, len, "union %s", name) >= len)
				goto out;
			return (buf);

		case CTF_K_ENUM:
			if (snprintf(p, len, "enum %s", name) >= len)
				goto out;
			return (buf);

		case CTF_K_VOLATILE:
			if (snprintf(p, len, "volatile ") >= len)
				goto out;
			type = tp->ctt_type;
			break;

		case CTF_K_CONST:
			if (snprintf(p, len, "const ") >= len)
				goto out;
			type = tp->ctt_type;
			break;

		case CTF_K_RESTRICT:
			if (snprintf(p, len, "restrict ") >= len)
				goto out;
			type = tp->ctt_type;
			break;

		default:
			(void) ctf_set_errno(ofp, ECTF_CORRUPT);
			return (NULL);
		}
	}
out:
	(void) ctf_set_errno(ofp, ECTF_NAMELEN);
	buf[0] = '\0';
	return (NULL);
}

/*
 * Resolve the type down to a base type node, and then return the size
 * of the type storage in bytes.
 */
ssize_t
ctf_type_size(ctf_file_t *fp, ctf_id_t type)
{
	const ctf_type_t *tp;
	ssize_t size;
	ctf_arinfo_t ar;

	if ((type = ctf_type_resolve(fp, type)) == CTF_ERR)
		return (-1); /* errno is set for us */

	if ((tp = ctf_lookup_by_id(&fp, type)) == NULL)
		return (-1); /* errno is set for us */

	switch (LCTF_INFO_KIND(fp, tp->ctt_info)) {
	case CTF_K_POINTER:
		return (fp->ctf_dmodel->ctd_pointer);

	case CTF_K_FUNCTION:
		return (0); /* function size is only known by symtab */

	case CTF_K_ENUM:
		return (fp->ctf_dmodel->ctd_int);

	case CTF_K_ARRAY:
		/*
		 * Array size is not directly returned by stabs data.  Instead,
		 * it defines the element type and requires the user to perform
		 * the multiplication.  If ctf_get_ctt_size() returns zero, the
		 * current version of ctfconvert does not compute member sizes
		 * and we compute the size here on its behalf.
		 */
		if ((size = ctf_get_ctt_size(fp, tp, NULL, NULL)) > 0)
			return (size);

		if (ctf_array_info(fp, type, &ar) == CTF_ERR ||
		    (size = ctf_type_size(fp, ar.ctr_contents)) == CTF_ERR)
			return (-1); /* errno is set for us */

		return (size * ar.ctr_nelems);

	default:
		return (ctf_get_ctt_size(fp, tp, NULL, NULL));
	}
}

/*
 * Resolve the type down to a base type node, and then return the alignment
 * needed for the type storage in bytes.
 */
ssize_t
ctf_type_align(ctf_file_t *fp, ctf_id_t type)
{
	const ctf_type_t *tp;
	ctf_arinfo_t r;

	if ((type = ctf_type_resolve(fp, type)) == CTF_ERR)
		return (-1); /* errno is set for us */

	if ((tp = ctf_lookup_by_id(&fp, type)) == NULL)
		return (-1); /* errno is set for us */

	switch (LCTF_INFO_KIND(fp, tp->ctt_info)) {
	case CTF_K_POINTER:
	case CTF_K_FUNCTION:
		return (fp->ctf_dmodel->ctd_pointer);

	case CTF_K_ARRAY:
		if (ctf_array_info(fp, type, &r) == CTF_ERR)
			return (-1); /* errno is set for us */
		return (ctf_type_align(fp, r.ctr_contents));

	case CTF_K_STRUCT:
	case CTF_K_UNION: {
		uint_t n = LCTF_INFO_VLEN(fp, tp->ctt_info);
		ssize_t size, increment;
		size_t align = 0;
		const void *vmp;

		(void) ctf_get_ctt_size(fp, tp, &size, &increment);
		vmp = (uchar_t *)tp + increment;

		if (LCTF_INFO_KIND(fp, tp->ctt_info) == CTF_K_STRUCT)
			n = MIN(n, 1); /* only use first member for structs */

		if (fp->ctf_version == CTF_VERSION_1 ||
		    size < CTF_LSTRUCT_THRESH) {
			const ctf_member_t *mp = vmp;
			for (; n != 0; n--, mp++) {
				ssize_t am = ctf_type_align(fp, mp->ctm_type);
				align = MAX(align, am);
			}
		} else {
			const ctf_lmember_t *lmp = vmp;
			for (; n != 0; n--, lmp++) {
				ssize_t am = ctf_type_align(fp, lmp->ctlm_type);
				align = MAX(align, am);
			}
		}

		return (align);
	}