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