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	"%Z%%M%	%I%	%E% SMI"
28
29/*
30 * DTrace Parsing Control Block
31 *
32 * A DTrace Parsing Control Block (PCB) contains all of the state that is used
33 * by a single pass of the D compiler, other than the global variables used by
34 * lex and yacc.  The routines in this file are used to set up and tear down
35 * PCBs, which are kept on a stack pointed to by the libdtrace global 'yypcb'.
36 * The main engine of the compiler, dt_compile(), is located in dt_cc.c and is
37 * responsible for calling these routines to begin and end a compilation pass.
38 *
39 * Sun's lex/yacc are not MT-safe or re-entrant, but we permit limited nested
40 * use of dt_compile() once the entire parse tree has been constructed but has
41 * not yet executed the "cooking" pass (see dt_cc.c for more information).  The
42 * PCB design also makes it easier to debug (since all global state is kept in
43 * one place) and could permit us to make the D compiler MT-safe or re-entrant
44 * in the future by adding locks to libdtrace or switching to Flex and Bison.
45 */
46
47#include <strings.h>
48#include <stdlib.h>
49#include <assert.h>
50
51#include <dt_impl.h>
52#include <dt_program.h>
53#include <dt_provider.h>
54#include <dt_pcb.h>
55
56/*
57 * Initialize the specified PCB by zeroing it and filling in a few default
58 * members, and then pushing it on to the top of the PCB stack and setting
59 * yypcb to point to it.  Increment the current handle's generation count.
60 */
61void
62dt_pcb_push(dtrace_hdl_t *dtp, dt_pcb_t *pcb)
63{
64	/*
65	 * Since lex/yacc are not re-entrant and we don't implement state save,
66	 * assert that if another PCB is active, it is from the same handle and
67	 * has completed execution of yyparse().  If the first assertion fires,
68	 * the caller is calling libdtrace without proper MT locking.  If the
69	 * second assertion fires, dt_compile() is being called recursively
70	 * from an illegal location in libdtrace, or a dt_pcb_pop() is missing.
71	 */
72	if (yypcb != NULL) {
73		assert(yypcb->pcb_hdl == dtp);
74		assert(yypcb->pcb_yystate == YYS_DONE);
75	}
76
77	bzero(pcb, sizeof (dt_pcb_t));
78
79	dt_scope_create(&pcb->pcb_dstack);
80	dt_idstack_push(&pcb->pcb_globals, dtp->dt_globals);
81	dt_irlist_create(&pcb->pcb_ir);
82
83	pcb->pcb_hdl = dtp;
84	pcb->pcb_prev = dtp->dt_pcb;
85
86	dtp->dt_pcb = pcb;
87	dtp->dt_gen++;
88
89	yyinit(pcb);
90}
91
92static int
93dt_pcb_pop_ident(dt_idhash_t *dhp, dt_ident_t *idp, void *arg)
94{
95	dtrace_hdl_t *dtp = arg;
96
97	if (idp->di_gen == dtp->dt_gen)
98		dt_idhash_delete(dhp, idp);
99
100	return (0);
101}
102
103/*
104 * Pop the topmost PCB from the PCB stack and destroy any data structures that
105 * are associated with it.  If 'err' is non-zero, destroy any intermediate
106 * state that is left behind as part of a compilation that has failed.
107 */
108void
109dt_pcb_pop(dtrace_hdl_t *dtp, int err)
110{
111	dt_pcb_t *pcb = yypcb;
112	uint_t i;
113
114	assert(pcb != NULL);
115	assert(pcb == dtp->dt_pcb);
116
117	while (pcb->pcb_dstack.ds_next != NULL)
118		(void) dt_scope_pop();
119
120	dt_scope_destroy(&pcb->pcb_dstack);
121	dt_irlist_destroy(&pcb->pcb_ir);
122
123	dt_node_link_free(&pcb->pcb_list);
124	dt_node_link_free(&pcb->pcb_hold);
125
126	if (err != 0) {
127		dt_xlator_t *dxp, *nxp;
128		dt_provider_t *pvp, *nvp;
129
130		if (pcb->pcb_prog != NULL)
131			dt_program_destroy(dtp, pcb->pcb_prog);
132		if (pcb->pcb_stmt != NULL)
133			dtrace_stmt_destroy(dtp, pcb->pcb_stmt);
134		if (pcb->pcb_ecbdesc != NULL)
135			dt_ecbdesc_release(dtp, pcb->pcb_ecbdesc);
136
137		for (dxp = dt_list_next(&dtp->dt_xlators); dxp; dxp = nxp) {
138			nxp = dt_list_next(dxp);
139			if (dxp->dx_gen == dtp->dt_gen)
140				dt_xlator_destroy(dtp, dxp);
141		}
142
143		for (pvp = dt_list_next(&dtp->dt_provlist); pvp; pvp = nvp) {
144			nvp = dt_list_next(pvp);
145			if (pvp->pv_gen == dtp->dt_gen)
146				dt_provider_destroy(dtp, pvp);
147		}
148
149		(void) dt_idhash_iter(dtp->dt_aggs, dt_pcb_pop_ident, dtp);
150		dt_idhash_update(dtp->dt_aggs);
151
152		(void) dt_idhash_iter(dtp->dt_globals, dt_pcb_pop_ident, dtp);
153		dt_idhash_update(dtp->dt_globals);
154
155		(void) dt_idhash_iter(dtp->dt_tls, dt_pcb_pop_ident, dtp);
156		dt_idhash_update(dtp->dt_tls);
157
158		(void) ctf_discard(dtp->dt_cdefs->dm_ctfp);
159		(void) ctf_discard(dtp->dt_ddefs->dm_ctfp);
160	}
161
162	if (pcb->pcb_pragmas != NULL)
163		dt_idhash_destroy(pcb->pcb_pragmas);
164	if (pcb->pcb_locals != NULL)
165		dt_idhash_destroy(pcb->pcb_locals);
166	if (pcb->pcb_idents != NULL)
167		dt_idhash_destroy(pcb->pcb_idents);
168	if (pcb->pcb_inttab != NULL)
169		dt_inttab_destroy(pcb->pcb_inttab);
170	if (pcb->pcb_strtab != NULL)
171		dt_strtab_destroy(pcb->pcb_strtab);
172	if (pcb->pcb_regs != NULL)
173		dt_regset_destroy(pcb->pcb_regs);
174
175	for (i = 0; i < pcb->pcb_asxreflen; i++)
176		dt_free(dtp, pcb->pcb_asxrefs[i]);
177
178	dt_free(dtp, pcb->pcb_asxrefs);
179	dt_difo_free(dtp, pcb->pcb_difo);
180
181	free(pcb->pcb_filetag);
182	free(pcb->pcb_sflagv);
183
184	dtp->dt_pcb = pcb->pcb_prev;
185	bzero(pcb, sizeof (dt_pcb_t));
186	yyinit(dtp->dt_pcb);
187}
188