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 */
52 static void
53 fix_ptrptr_to_struct(tdata_t *td)
54 {
55 char *strs[2] = { "as", "fdbuffer" };
56 char *mems[2] = { "a_objectdir", "fd_shadow" };
57 char *acts[2] = { "vnode", "page" };
58 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 < 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
106 static void
107 fix_ptr_to_struct(tdata_t *td)
108 {
109 char *strs[2] = { "vmem", "id_space" };
110 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 < 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 */
153 void
154 cvt_fixstabs(tdata_t *td)
155 {
156 fix_ptrptr_to_struct(td);
157 fix_ptr_to_struct(td);
158 }
159
160 struct match {
161 tdesc_t *m_ret;
162 const char *m_name;
163 };
164
165 static int
166 matching_iidesc(iidesc_t *iidesc, struct match *match)
167 {
168 if (!streq(iidesc->ii_name, match->m_name))
169 return (0);
170
171 if (iidesc->ii_type != II_TYPE && iidesc->ii_type != II_SOU)
172 return (0);
173
174 match->m_ret = iidesc->ii_dtype;
175 return (-1);
176 }
177
178 static tdesc_t *
179 lookup_tdesc(tdata_t *td, const char *name)
180 {
181 struct match match = { NULL, name };
182 iter_iidescs_by_name(td, name, (int (*)())matching_iidesc, &match);
183 return (match.m_ret);
184 }
185
186 /*
187 * The cpu structure grows, with the addition of a machcpu member, if
188 * _MACHDEP is defined. This means that, for example, the cpu structure
189 * in unix is different from the cpu structure in genunix. As one might
190 * expect, this causes merges to fail. Since everyone indirectly contains
191 * a pointer to a CPU structure, the failed merges can cause massive amounts
192 * of duplication. In the case of unix uniquifying against genunix, upwards
193 * of 50% of the structures were unmerged due to this problem. We fix this
194 * by adding a cpu_m member. If machcpu hasn't been defined in our module,
195 * we make a forward node for it.
196 */
197 static void
198 fix_small_cpu_struct(tdata_t *td, size_t ptrsize)
199 {
200 tdesc_t *cput, *cpu;
201 tdesc_t *machcpu;
202 mlist_t *ml, *lml;
203 mlist_t *cpum;
204 int foundcpucyc = 0;
205
206 /*
207 * We're going to take the circuitous route finding the cpu structure,
208 * because we want to make sure that we find the right one. It would
209 * be nice if we could verify the header name too. DWARF might not
210 * have the cpu_t, so we let this pass.
211 */
212 if ((cput = lookup_tdesc(td, "cpu_t")) != NULL) {
213 if (cput->t_type != TYPEDEF)
214 return;
215 cpu = cput->t_tdesc;
216 } else {
217 cpu = lookup_tdesc(td, "cpu");
218 }
219
220 if (cpu == NULL)
221 return;
222
223 if (!streq(cpu->t_name, "cpu") || cpu->t_type != STRUCT)
224 return;
225
226 for (ml = cpu->t_members, lml = NULL; ml;
227 lml = ml, ml = ml->ml_next) {
228 if (strcmp(ml->ml_name, "cpu_cyclic") == 0)
229 foundcpucyc = 1;
230 }
231
232 if (foundcpucyc == 0 || lml == NULL ||
233 strcmp(lml->ml_name, "cpu_m") == 0)
234 return;
235
236 /*
237 * We need to derive the right offset for the fake cpu_m member. To do
238 * that, we require a special unused member to be the last member
239 * before the 'cpu_m', that we encode knowledge of here. ABI alignment
240 * on all platforms is such that we only need to add a pointer-size
241 * number of bits to get the right offset for cpu_m. This would most
242 * likely break if gcc's -malign-double were ever used, but that option
243 * breaks the ABI anyway.
244 */
245 if (!streq(lml->ml_name, "cpu_m_pad") &&
246 getenv("CTFCONVERT_PERMISSIVE") == NULL) {
247 terminate("last cpu_t member before cpu_m is %s; "
248 "it must be cpu_m_pad.\n", lml->ml_name);
249 }
250
251 if ((machcpu = lookup_tdesc(td, "machcpu")) == NULL) {
252 machcpu = xcalloc(sizeof (*machcpu));
253 machcpu->t_name = xstrdup("machcpu");
254 machcpu->t_id = td->td_nextid++;
255 machcpu->t_type = FORWARD;
256 } else if (machcpu->t_type != STRUCT) {
257 return;
258 }
259
260 debug(3, "Adding cpu_m machcpu %s to cpu struct\n",
261 (machcpu->t_type == FORWARD ? "forward" : "struct"));
262
263 cpum = xmalloc(sizeof (*cpum));
264 cpum->ml_offset = lml->ml_offset + (ptrsize * NBBY);
265 cpum->ml_size = 0;
266 cpum->ml_name = xstrdup("cpu_m");
267 cpum->ml_type = machcpu;
268 cpum->ml_next = NULL;
269
270 lml->ml_next = cpum;
271 }
272
273 void
274 cvt_fixups(tdata_t *td, size_t ptrsize)
275 {
276 fix_small_cpu_struct(td, ptrsize);
277 }