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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28/*
29 * Workarounds for stabs generation bugs in the compiler and general needed
30 * fixups.
31 */
32
33#include <stdio.h>
34#include <strings.h>
35
36#include "ctf_headers.h"
37#include "ctftools.h"
38#include "hash.h"
39#include "memory.h"
40
41/*
42 * Due to 4432619, the 6.1 compiler will sometimes incorrectly generate pointer
43 * stabs.  Given a struct foo, and a corresponding typedef struct foo foo_t.
44 * In some cases, when faced with a pointer to a foo_t, the compiler will
45 * sometimes generate a stab that describes a pointer to a struct foo.
46 * Regardless of correctness, this breaks merges, as it occurs inconsistently
47 * by file.  The following two routines know how to recognize and repair foo_t *
48 * and foo_t ** bugs in a specific set of cases.  There is no general way to
49 * solve this problem without a fix to the compiler.  In general, cases should
50 * only be added to these routines to fix merging problems in genunix.
51 */
52static void
53fix_ptrptr_to_struct(tdata_t *td)
54{
55	const char *strs[2] = { "as", "fdbuffer" };
56	const char *mems[2] = { "a_objectdir", "fd_shadow" };
57	const char *acts[2] = { "vnode", "page" };
58	const char *tgts[2] = { "vnode_t", "page_t" };
59	tdesc_t *str;
60	tdesc_t *act, *tgt;
61	tdesc_t *p1, *p2;
62	mlist_t *ml;
63	int i;
64
65	for (i = 0; i < (int) (sizeof (strs) / sizeof (strs[0])); i++) {
66		if (!(str = lookupname(strs[i])) || str->t_type != STRUCT)
67			continue;
68
69		for (ml = str->t_members; ml; ml = ml->ml_next) {
70			if (streq(ml->ml_name, mems[i]))
71				break;
72		}
73		if (!ml)
74			continue;
75
76		if (ml->ml_type->t_type != POINTER || ml->ml_type->t_name ||
77		    ml->ml_type->t_tdesc->t_type != POINTER ||
78		    ml->ml_type->t_tdesc->t_name)
79			continue;
80
81		act = ml->ml_type->t_tdesc->t_tdesc;
82		if (act->t_type != STRUCT || !streq(act->t_name, acts[i]))
83			continue;
84
85		if (!(tgt = lookupname(tgts[i])) || tgt->t_type != TYPEDEF)
86			continue;
87
88		/* We have an instance of the bug */
89		p2 = xcalloc(sizeof (*p2));
90		p2->t_type = POINTER;
91		p2->t_id = td->td_nextid++;
92		p2->t_tdesc = tgt;
93
94		p1 = xcalloc(sizeof (*p1));
95		p1->t_type = POINTER;
96		p1->t_id = td->td_nextid++;
97		p1->t_tdesc = p2;
98
99		ml->ml_type = p1;
100
101		debug(3, "Fixed %s->%s => ptrptr struct %s bug\n",
102		    strs[i], mems[i], acts[i]);
103	}
104}
105
106static void
107fix_ptr_to_struct(tdata_t *td)
108{
109	const char *strs[2] = { "vmem", "id_space" };
110	const char *mems[2] = { NULL, "is_vmem" };
111	tdesc_t *ptr = NULL;
112	tdesc_t *str, *vmt;
113	mlist_t *ml;
114	int i;
115
116	if ((vmt = lookupname("vmem_t")) == NULL || vmt->t_type != TYPEDEF)
117		return;
118
119	for (i = 0; i < (int) (sizeof (strs) / sizeof (strs[0])); i++) {
120		if (!(str = lookupname(strs[i])) || str->t_type != STRUCT)
121			continue;
122
123		for (ml = str->t_members; ml; ml = ml->ml_next) {
124			if (mems[i] && !streq(ml->ml_name, mems[i]))
125				continue;
126
127			if (ml->ml_type->t_type != POINTER ||
128			    ml->ml_type->t_name ||
129			    (ml->ml_type->t_tdesc->t_type != STRUCT &&
130			    ml->ml_type->t_tdesc->t_type != FORWARD) ||
131			    !streq(ml->ml_type->t_tdesc->t_name, "vmem"))
132				continue;
133
134			debug(3, "Fixed %s->%s => ptr struct vmem bug\n",
135			    strs[i], ml->ml_name);
136
137			if (!ptr) {
138				ptr = xcalloc(sizeof (*ptr));
139				ptr->t_type = POINTER;
140				ptr->t_id = td->td_nextid++;
141				ptr->t_tdesc = vmt;
142			}
143
144			ml->ml_type = ptr;
145		}
146	}
147}
148
149/*
150 * Fix stabs generation bugs.  These routines must be run before the
151 * post-conversion merge
152 */
153void
154cvt_fixstabs(tdata_t *td)
155{
156	fix_ptrptr_to_struct(td);
157	fix_ptr_to_struct(td);
158}
159
160struct match {
161	tdesc_t *m_ret;
162	const char *m_name;
163};
164
165static int
166matching_iidesc(void *arg1, void *arg2)
167{
168	iidesc_t *iidesc = arg1;
169	struct match *match = arg2;
170	if (!streq(iidesc->ii_name, match->m_name))
171		return (0);
172
173	if (iidesc->ii_type != II_TYPE && iidesc->ii_type != II_SOU)
174		return (0);
175
176	match->m_ret = iidesc->ii_dtype;
177	return (-1);
178}
179
180static tdesc_t *
181lookup_tdesc(tdata_t *td, char const *name)
182{
183	struct match match = { NULL, name };
184	iter_iidescs_by_name(td, name, matching_iidesc, &match);
185	return (match.m_ret);
186}
187
188/*
189 * The cpu structure grows, with the addition of a machcpu member, if
190 * _MACHDEP is defined.  This means that, for example, the cpu structure
191 * in unix is different from the cpu structure in genunix.  As one might
192 * expect, this causes merges to fail.  Since everyone indirectly contains
193 * a pointer to a CPU structure, the failed merges can cause massive amounts
194 * of duplication.  In the case of unix uniquifying against genunix, upwards
195 * of 50% of the structures were unmerged due to this problem.  We fix this
196 * by adding a cpu_m member.  If machcpu hasn't been defined in our module,
197 * we make a forward node for it.
198 */
199static void
200fix_small_cpu_struct(tdata_t *td, size_t ptrsize)
201{
202	tdesc_t *cput, *cpu;
203	tdesc_t *machcpu;
204	mlist_t *ml, *lml;
205	mlist_t *cpum;
206	int foundcpucyc = 0;
207
208	/*
209	 * We're going to take the circuitous route finding the cpu structure,
210	 * because we want to make sure that we find the right one.  It would
211	 * be nice if we could verify the header name too.  DWARF might not
212	 * have the cpu_t, so we let this pass.
213	 */
214	if ((cput = lookup_tdesc(td, "cpu_t")) != NULL) {
215		if (cput->t_type != TYPEDEF)
216			return;
217		cpu = cput->t_tdesc;
218	} else {
219		cpu = lookup_tdesc(td, "cpu");
220	}
221
222	if (cpu == NULL)
223		return;
224
225	if (!streq(cpu->t_name, "cpu") || cpu->t_type != STRUCT)
226		return;
227
228	for (ml = cpu->t_members, lml = NULL; ml;
229	    lml = ml, ml = ml->ml_next) {
230		if (strcmp(ml->ml_name, "cpu_cyclic") == 0)
231			foundcpucyc = 1;
232	}
233
234	if (foundcpucyc == 0 || lml == NULL ||
235	    strcmp(lml->ml_name, "cpu_m") == 0)
236		return;
237
238	/*
239	 * We need to derive the right offset for the fake cpu_m member.  To do
240	 * that, we require a special unused member to be the last member
241	 * before the 'cpu_m', that we encode knowledge of here.  ABI alignment
242	 * on all platforms is such that we only need to add a pointer-size
243	 * number of bits to get the right offset for cpu_m.  This would most
244	 * likely break if gcc's -malign-double were ever used, but that option
245	 * breaks the ABI anyway.
246	 */
247	if (!streq(lml->ml_name, "cpu_m_pad") &&
248	    getenv("CTFCONVERT_PERMISSIVE") == NULL) {
249		terminate("last cpu_t member before cpu_m is %s; "
250		    "it must be cpu_m_pad.\n", lml->ml_name);
251	}
252
253	if ((machcpu = lookup_tdesc(td, "machcpu")) == NULL) {
254		machcpu = xcalloc(sizeof (*machcpu));
255		machcpu->t_name = xstrdup("machcpu");
256		machcpu->t_id = td->td_nextid++;
257		machcpu->t_type = FORWARD;
258	} else if (machcpu->t_type != STRUCT) {
259		return;
260	}
261
262	debug(3, "Adding cpu_m machcpu %s to cpu struct\n",
263	    (machcpu->t_type == FORWARD ? "forward" : "struct"));
264
265	cpum = xmalloc(sizeof (*cpum));
266	cpum->ml_offset = lml->ml_offset + (ptrsize * NBBY);
267	cpum->ml_size = 0;
268	cpum->ml_name = xstrdup("cpu_m");
269	cpum->ml_type = machcpu;
270	cpum->ml_next = NULL;
271
272	lml->ml_next = cpum;
273}
274
275void
276cvt_fixups(tdata_t *td, size_t ptrsize)
277{
278	fix_small_cpu_struct(td, ptrsize);
279}
280