src/native/jvmti/cacaodbgserver.c

   1 /* src/native/jvmti/cacaodbgserver.c - contains the cacaodbgserver process. This
   2                                        process controls the cacao vm through gdb
   3
   4    Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
   5    C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
   6    E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
   7    J. Wenninger, Institut f. Computersprachen - TU Wien
   8
   9    This file is part of CACAO.
  10
  11    This program is free software; you can redistribute it and/or
  12    modify it under the terms of the GNU General Public License as
  13    published by the Free Software Foundation; either version 2, or (at
  14    your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful, but
  17    WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19    General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  24    02111-1307, USA.
  25
  26    Contact: cacao@complang.tuwien.ac.at
  27
  28    Authors: Martin Platter
  29
  30    Changes: Edwin Steiner
  31             Samuel Vinson
  32
  33    $Id$
  34
  35 */
  36
  37 #include "native/jvmti/cacaodbgserver.h"
  38 #include "native/jvmti/cacaodbg.h"
  39 #include "native/jvmti/dbg.h"
  40 #include <sys/types.h>
  41 #include <unistd.h>
  42 #include <signal.h>
  43 #include <sys/wait.h>
  44 #include <stdlib.h>
  45 #include <stdio.h>
  46 #include <assert.h>
  47 #include <string.h>
  48
  49 FILE *gdbin, *gdbout; /* file descriptor for gdb pipes */
  50
  51 struct _pending_brkpt {
  52         int brknumber;
  53         unsigned long threadid;
  54         char* regs;
  55 };
  56
  57 struct _pending_brkpt *pending_brkpts;
  58 int pending_brkpts_size;
  59
  60
  61 static void closepipeend (int fd) {
  62         if (close(fd) == -1) {
  63                 perror("unable to close pipe - ");
  64                 exit(1);
  65         }
  66 }
  67
  68 /* startgdb *******************************************************************
  69
  70    starts a gdb session and creates two pipes connection gdb stdout/stdin to
  71    gdbin/gdbout
  72
  73 *******************************************************************************/
  74
  75 static void startgdb() {
  76         char gdbargs[20];
  77         int cacao2gdbpipe[2],gdb2cacaopipe[2];
  78
  79         pipe(cacao2gdbpipe);
  80         pipe(gdb2cacaopipe);
  81
  82         snprintf(gdbargs,20,"--pid=%d",getppid());
  83
  84         switch(fork()) {
  85         case -1:
  86                 fprintf(stderr,"cacaodbgserver: fork error\n");
  87                 exit(1);
  88         case 0:
  89                 /* child */
  90                 closepipeend(gdb2cacaopipe[0]); /* read end */
  91                 closepipeend(cacao2gdbpipe[1]); /* write end */
  92
  93                 /* connect stdin of gdb to cacao2gdbpipe */
  94                 dup2(cacao2gdbpipe[0],0);
  95                 /* connect stdout of gdb to gdb2cacaopipe */
  96                 dup2(gdb2cacaopipe[1],1);
  97
  98                 if (execlp("gdb","gdb","--interpreter=mi" ,gdbargs,(char *) NULL)==-1){
  99                         fprintf(stderr,"cacaodbgserver: unable to start gdb\n");
 100                         exit(1);
 101                 }
 102         default:
 103                 /* parent */
 104                 closepipeend(gdb2cacaopipe[1]); /* write end */
 105                 closepipeend(cacao2gdbpipe[0]); /* read end */
 106
 107                 gdbin = fdopen(gdb2cacaopipe[0],"r");
 108                 gdbout = fdopen(cacao2gdbpipe[1],"w");
 109         }
 110
 111 }
 112
 113
 114 #define SENDCMD(CMD) \
 115         fprintf(gdbout,"%s",CMD); \
 116         fflush(gdbout); \
 117
 118
 119 static void getgdboutput(char *inbuf,int buflen) {
 120         int i=0;
 121         inbuf[0]='\0';
 122         do {
 123                 i += strlen(&inbuf[i]);
 124                 if (fgets(&inbuf[i],buflen-i,gdbin)==NULL) {
 125                         perror("cacaodbgserver: ");
 126                         exit(1);
 127                 }
 128         } while(!(strncmp(OUTPUTEND,&inbuf[i],OUTPUTENDSIZE)==0));
 129 }
 130
 131
 132 /* dataevaluate ***************************************************************
 133
 134    evaluates expr returning long in gdb and returns the result
 135
 136 *******************************************************************************/
 137
 138 static unsigned long dataevaluate(char *expr) {
 139         char *match, inbuf[160];
 140
 141         fprintf(gdbout,"-data-evaluate-expression %s\n",expr);
 142         fflush(gdbout);
 143
 144         getgdboutput(inbuf,160);
 145         if ((match=strstr(inbuf,DATAEVALUATE)) == NULL) {
 146                 fprintf(stderr,"dataevaluate: no matching value\n");
 147                 return -1;
 148         }
 149         return strtoll(&match[strlen(DATAEVALUATE)], NULL, 16);
 150 }
 151
 152
 153 /* commonbreakpointhandler *****************************************************
 154
 155    called by gdb and hard coded breakpoint handler
 156
 157 *******************************************************************************/
 158
 159 static bool commonbreakpointhandler(char* sigbuf, int sigtrap) {
 160         int numberofbreakpoints, i;
 161         char tmp[INBUFLEN], *match;
 162         unsigned long addr;
 163
 164         if ((match=strstr(sigbuf,SIGADDR))==NULL) {
 165                 fprintf(stderr,"commonbreakpointhandler: no matching address(%s)\n",
 166                                 sigbuf);
 167                 return true;
 168         }
 169
 170         addr = strtoll(&match[strlen(SIGADDR)],NULL,16);
 171         if (sigtrap) addr--;
 172
 173
 174         numberofbreakpoints = (int)dataevaluate("dbgcom->jvmtibrkpt.num");
 175
 176         i = -1;
 177         do {
 178                 i++;
 179                 snprintf(tmp,INBUFLEN,"dbgcom->jvmtibrkpt.brk[%d].addr",i);
 180         } while ((i<numberofbreakpoints) && (dataevaluate(tmp) != addr));
 181
 182         assert(i<numberofbreakpoints);
 183
 184         /* handle system breakpoints */
 185         switch(i) {
 186         case SETSYSBRKPT:
 187                 /* add a breakpoint */
 188                 fprintf(gdbout,"break *0x%lx\n",dataevaluate("dbgcom->brkaddr"));
 189                 fflush(gdbout);
 190                 getgdboutput(tmp,INBUFLEN);
 191                 break;
 192         case CACAODBGSERVERQUIT:
 193                 SENDCMD("-gdb-exit\n");
 194                 return false;
 195         default:
 196                 /* other breakpoints -> call jvmti_cacao_generic_breakpointhandler
 197                    in the cacao vm */
 198                 fprintf(gdbout,"call jvmti_cacao_generic_breakpointhandler(%d)\n",i);
 199                 fflush(gdbout);
 200                 getgdboutput(tmp,INBUFLEN);
 201         }
 202         SENDCMD(CONTINUE);
 203         getgdboutput(tmp,INBUFLEN);
 204         return true;
 205 }
 206
 207 /* controlloop ****************************************************************
 208
 209    this function controls the gdb behaviour
 210
 211 *******************************************************************************/
 212
 213 static void controlloop() {
 214         char inbuf[INBUFLEN], *match;
 215         bool running = true;
 216
 217         pending_brkpts_size = 5;
 218         pending_brkpts = malloc(sizeof(struct _pending_brkpt)*pending_brkpts_size);
 219
 220         getgdboutput(inbuf,INBUFLEN);   /* read gdb welcome message */
 221
 222         SENDCMD("handle SIGSEGV SIGPWR SIGXCPU SIGBUS noprint nostop\n");
 223         getgdboutput(inbuf,INBUFLEN);
 224
 225         SENDCMD("print dbgcom\n");
 226         getgdboutput(inbuf,INBUFLEN);
 227
 228         SENDCMD(CONTINUE);
 229         getgdboutput(inbuf,INBUFLEN);
 230
 231         while(running) {
 232                 getgdboutput(inbuf,INBUFLEN);
 233
 234                 if ((match=strstr(inbuf,HCSIGTRAP))!=NULL) {
 235                         running = commonbreakpointhandler(match,1);
 236                         continue;
 237                         }
 238
 239                 if ((match=strstr(inbuf,GDBBREAKPOINT))!=NULL) {
 240                         running = commonbreakpointhandler(match,0);
 241                         continue;
 242                 }
 243
 244                 if (strstr(inbuf,EXITEDNORMALLY) != NULL) {
 245                         /* quit gdb */
 246                         SENDCMD ("-gdb-exit");
 247                         running = false;
 248                         continue;
 249                 }
 250
 251                 if ((inbuf[0]!=LOGSTREAMOUTPUT) && (inbuf[0]!=CONSOLESTREAMOUTPUT)) {
 252                         fprintf(stderr,"gdbin not handled %s\n",inbuf);
 253                         fprintf(gdbout,"bt\n");
 254                         fflush(gdbout);
 255                         fprintf(stderr,"not handled 1\n");
 256                         fflush(stderr);
 257                         getgdboutput(inbuf,INBUFLEN);
 258                         fprintf(stderr,"gdbin: %s\n",inbuf);
 259                         SENDCMD("-gdb-exit\n");
 260                         return;
 261                 }
 262         }
 263
 264         free(pending_brkpts);
 265 }
 266
 267 /* main (cacaodbgserver) ******************************************************
 268
 269    main function for cacaodbgserver process.
 270
 271 *******************************************************************************/
 272
 273 int main(int argc, char **argv) {
 274         startgdb();
 275
 276         controlloop();
 277
 278         return 0;
 279 }
 280
 281
 282 /*
 283  * These are local overrides for various environment variables in Emacs.
 284  * Please do not remove this and leave it at the end of the file, where
 285  * Emacs will automagically detect them.
 286  * ---------------------------------------------------------------------
 287  * Local variables:
 288  * mode: c
 289  * indent-tabs-mode: t
 290  * c-basic-offset: 4
 291  * tab-width: 4
 292  * End:
 293  * vim:noexpandtab:sw=4:ts=4:
 294  */