1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"@(#)ctf_decl.c	1.2	05/06/08 SMI"
28
29/*
30 * CTF Declaration Stack
31 *
32 * In order to implement ctf_type_name(), we must convert a type graph back
33 * into a C type declaration.  Unfortunately, a type graph represents a storage
34 * class ordering of the type whereas a type declaration must obey the C rules
35 * for operator precedence, and the two orderings are frequently in conflict.
36 * For example, consider these CTF type graphs and their C declarations:
37 *
38 * CTF_K_POINTER -> CTF_K_FUNCTION -> CTF_K_INTEGER  : int (*)()
39 * CTF_K_POINTER -> CTF_K_ARRAY -> CTF_K_INTEGER     : int (*)[]
40 *
41 * In each case, parentheses are used to raise operator * to higher lexical
42 * precedence, so the string form of the C declaration cannot be constructed by
43 * walking the type graph links and forming the string from left to right.
44 *
45 * The functions in this file build a set of stacks from the type graph nodes
46 * corresponding to the C operator precedence levels in the appropriate order.
47 * The code in ctf_type_name() can then iterate over the levels and nodes in
48 * lexical precedence order and construct the final C declaration string.
49 */
50
51#include <ctf_impl.h>
52
53void
54ctf_decl_init(ctf_decl_t *cd, char *buf, size_t len)
55{
56	int i;
57
58	bzero(cd, sizeof (ctf_decl_t));
59
60	for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++)
61		cd->cd_order[i] = CTF_PREC_BASE - 1;
62
63	cd->cd_qualp = CTF_PREC_BASE;
64	cd->cd_ordp = CTF_PREC_BASE;
65
66	cd->cd_buf = buf;
67	cd->cd_ptr = buf;
68	cd->cd_end = buf + len;
69}
70
71void
72ctf_decl_fini(ctf_decl_t *cd)
73{
74	ctf_decl_node_t *cdp, *ndp;
75	int i;
76
77	for (i = CTF_PREC_BASE; i < CTF_PREC_MAX; i++) {
78		for (cdp = ctf_list_next(&cd->cd_nodes[i]);
79		    cdp != NULL; cdp = ndp) {
80			ndp = ctf_list_next(cdp);
81			ctf_free(cdp, sizeof (ctf_decl_node_t));
82		}
83	}
84}
85
86void
87ctf_decl_push(ctf_decl_t *cd, ctf_file_t *fp, ctf_id_t type)
88{
89	ctf_decl_node_t *cdp;
90	ctf_decl_prec_t prec;
91	uint_t kind, n = 1;
92	int is_qual = 0;
93
94	const ctf_type_t *tp;
95	ctf_arinfo_t ar;
96
97	if ((tp = ctf_lookup_by_id(&fp, type)) == NULL) {
98		cd->cd_err = fp->ctf_errno;
99		return;
100	}
101
102	switch (kind = LCTF_INFO_KIND(fp, tp->ctt_info)) {
103	case CTF_K_ARRAY:
104		(void) ctf_array_info(fp, type, &ar);
105		ctf_decl_push(cd, fp, ar.ctr_contents);
106		n = ar.ctr_nelems;
107		prec = CTF_PREC_ARRAY;
108		break;
109
110	case CTF_K_TYPEDEF:
111		if (ctf_strptr(fp, tp->ctt_name)[0] == '\0') {
112			ctf_decl_push(cd, fp, tp->ctt_type);
113			return;
114		}
115		prec = CTF_PREC_BASE;
116		break;
117
118	case CTF_K_FUNCTION:
119		ctf_decl_push(cd, fp, tp->ctt_type);
120		prec = CTF_PREC_FUNCTION;
121		break;
122
123	case CTF_K_POINTER:
124		ctf_decl_push(cd, fp, tp->ctt_type);
125		prec = CTF_PREC_POINTER;
126		break;
127
128	case CTF_K_VOLATILE:
129	case CTF_K_CONST:
130	case CTF_K_RESTRICT:
131		ctf_decl_push(cd, fp, tp->ctt_type);
132		prec = cd->cd_qualp;
133		is_qual++;
134		break;
135
136	default:
137		prec = CTF_PREC_BASE;
138	}
139
140	if ((cdp = ctf_alloc(sizeof (ctf_decl_node_t))) == NULL) {
141		cd->cd_err = EAGAIN;
142		return;
143	}
144
145	cdp->cd_type = type;
146	cdp->cd_kind = kind;
147	cdp->cd_n = n;
148
149	if (ctf_list_next(&cd->cd_nodes[prec]) == NULL)
150		cd->cd_order[prec] = cd->cd_ordp++;
151
152	/*
153	 * Reset cd_qualp to the highest precedence level that we've seen so
154	 * far that can be qualified (CTF_PREC_BASE or CTF_PREC_POINTER).
155	 */
156	if (prec > cd->cd_qualp && prec < CTF_PREC_ARRAY)
157		cd->cd_qualp = prec;
158
159	/*
160	 * C array declarators are ordered inside out so prepend them.  Also by
161	 * convention qualifiers of base types precede the type specifier (e.g.
162	 * const int vs. int const) even though the two forms are equivalent.
163	 */
164	if (kind == CTF_K_ARRAY || (is_qual && prec == CTF_PREC_BASE))
165		ctf_list_prepend(&cd->cd_nodes[prec], cdp);
166	else
167		ctf_list_append(&cd->cd_nodes[prec], cdp);
168}
169
170/*PRINTFLIKE2*/
171void
172ctf_decl_sprintf(ctf_decl_t *cd, const char *format, ...)
173{
174	size_t len = (size_t)(cd->cd_end - cd->cd_ptr);
175	va_list ap;
176	size_t n;
177
178	va_start(ap, format);
179	n = vsnprintf(cd->cd_ptr, len, format, ap);
180	va_end(ap);
181
182	cd->cd_ptr += MIN(n, len);
183	cd->cd_len += n;
184}
185