- int i;
- /* to get the backtrace from the libc */
- char **backtrace = backtrace_symbols (e->bt, e->used);
-
- /* To build the commandline of addr2line */
- char *cmd, *curr;
-
- /* to extract the addresses from the backtrace */
- char **addrs=xbt_new(char*,e->used);
- char buff[256],*p;
-
- /* To read the output of addr2line */
- FILE *pipe;
- char line_func[1024],line_pos[1024];
-
- /* size (in char) of pointers on this arch */
- int addr_len=0;
-
- /* To search for the right executable path when not trivial */
- struct stat stat_buf;
- char *binary_name = NULL;
-
- /* Some arches only have stubs of backtrace, no implementation (hppa comes to mind) */
- if (!e->used)
- return;
-
- /* build the commandline */
- if (stat(xbt_binary_name,&stat_buf)) {
- /* Damn. binary not in current dir. We'll have to dig the PATH to find it */
- int i;
- for (i=0; environ[i]; i++) {
- if (!strncmp("PATH=",environ[i], 5)) {
- xbt_dynar_t path=xbt_str_split(environ[i] + 5, ":");
- unsigned int cpt;
- char *data;
- xbt_dynar_foreach(path, cpt, data) {
- if (binary_name)
- free(binary_name);
- binary_name = bprintf("%s/%s",data,xbt_binary_name);
- if (!stat(binary_name,&stat_buf)) {
- /* Found. */
- DEBUG1("Looked in the PATH for the binary. Found %s",binary_name);
- xbt_dynar_free(&path);
- break;
- }
- }
- if (stat(binary_name,&stat_buf)) {
- /* not found */
- e->used = 1;
- e->bt_strings = xbt_new(char*,1);
- e->bt_strings[0] = bprintf("(binary '%s' not found the path)",xbt_binary_name);
- return;
- }
- xbt_dynar_free(&path);
- break;
- }
- }
- } else {
- binary_name = xbt_strdup(xbt_binary_name);
- }
- cmd = curr = xbt_new(char,strlen(ADDR2LINE)+25+strlen(binary_name)+32*e->used);
-
- curr += sprintf(curr,"%s -f -e %s ",ADDR2LINE,binary_name);
- free(binary_name);
-
- for (i=0; i<e->used;i++) {
- /* retrieve this address */
- DEBUG2("Retrieving address number %d from '%s'", i, backtrace[i]);
- snprintf(buff,256,"%s",strchr(backtrace[i],'[')+1);
- p=strchr(buff,']');
- *p='\0';
- if (strcmp(buff,"(nil)"))
- addrs[i]=bprintf("%s", buff);
- else
- addrs[i]=bprintf("0x0");
- DEBUG3("Set up a new address: %d, '%s'(%p)", i, addrs[i], addrs[i]);
-
- /* Add it to the command line args */
- curr+=sprintf(curr,"%s ",addrs[i]);
- }
- addr_len = strlen(addrs[0]);
-
- /* parse the output and build a new backtrace */
- e->bt_strings = xbt_new(char*,e->used);
-
- VERB1("Fire a first command: '%s'", cmd);
- pipe = popen(cmd, "r");
- if (!pipe) {
- CRITICAL0("Cannot fork addr2line to display the backtrace");
- abort();
- }
-
- for (i=0; i<e->used; i++) {
- DEBUG2("Looking for symbol %d, addr = '%s'", i, addrs[i]);
- fgets(line_func,1024,pipe);
- line_func[strlen(line_func)-1]='\0';
- fgets(line_pos,1024,pipe);
- line_pos[strlen(line_pos)-1]='\0';
-
- if (strcmp("??",line_func)) {
- DEBUG2("Found static symbol %s() at %s", line_func, line_pos);
- e->bt_strings[i] = bprintf("** In %s() at %s", line_func,line_pos);
- } else {
- /* Damn. The symbol is in a dynamic library. Let's get wild */
- char *maps_name;
- FILE *maps;
- char maps_buff[512];
-
- long int addr,offset=0;
- char *p,*p2;
-
- char *subcmd;
- FILE *subpipe;
- int found=0;
-
- /* let's look for the offset of this library in our addressing space */
- maps_name=bprintf("/proc/%d/maps",(int)getpid());
- maps=fopen(maps_name,"r");
-
- sscanf(addrs[i],"%lx",&addr);
- sprintf(maps_buff,"%#lx",addr);
-
- if (strcmp(addrs[i],maps_buff)) {
- CRITICAL2("Cannot parse backtrace address '%s' (addr=%#lx)",
- addrs[i], addr);
- }
- DEBUG2("addr=%s (as string) =%#lx (as number)",addrs[i],addr);
-
- while (!found) {
- long int first, last;
- if (fgets(maps_buff,512,maps) == NULL)
- break;
- if (i==0) {
- maps_buff[strlen(maps_buff) -1]='\0';
- DEBUG1("map line: %s", maps_buff);
- }
- sscanf(maps_buff,"%lx",&first);
- p=strchr(maps_buff,'-')+1;
- sscanf(p,"%lx",&last);
- if (first < addr && addr < last) {
- offset = first;
- found=1;
- }
- if (found) {
- DEBUG3("%#lx in [%#lx-%#lx]", addr, first,last);
- DEBUG0("Symbol found, map lines not further displayed (even if looking for next ones)");
- }
- }
- fclose(maps);
- free(maps_name);
-
- if (!found) {
- VERB0("Problem while reading the maps file. Following backtrace will be mangled.");
- DEBUG1("No dynamic. Static symbol: %s", backtrace[i]);
- e->bt_strings[i] = bprintf("** In ?? (%s)", backtrace[i]);
- continue;
- }
-
- /* Ok, Found the offset of the maps line containing the searched symbol.
- We now need to substract this from the address we got from backtrace.
- */
-
- free(addrs[i]);
- addrs[i] = bprintf("0x%0*lx",addr_len-2,addr-offset);
- DEBUG2("offset=%#lx new addr=%s",offset,addrs[i]);
-
- /* Got it. We have our new address. Let's get the library path and we
- are set */
- p = xbt_strdup(backtrace[i]);
- if (p[0]=='[') {
- /* library path not displayed in the map file either... */
- free(p);
- sprintf(line_func,"??");
- } else {
- p2 = strrchr(p,'(');
- if (p2) *p2= '\0';
- p2 = strrchr(p,' ');
- if(p2) *p2= '\0';
-
- /* Here we go, fire an addr2line up */
- subcmd = bprintf("%s -f -e %s %s",ADDR2LINE,p, addrs[i]);
- free(p);
- VERB1("Fire a new command: '%s'",subcmd);
- subpipe = popen(subcmd,"r");
- if (!subpipe) {
- CRITICAL0("Cannot fork addr2line to display the backtrace");
- abort();
- }
- fgets(line_func,1024,subpipe);
- line_func[strlen(line_func)-1]='\0';
- fgets(line_pos,1024,subpipe);
- line_pos[strlen(line_pos)-1]='\0';
- pclose(subpipe);
- free(subcmd);
- }
-
- /* check whether the trick worked */
- if (strcmp("??",line_func)) {
- DEBUG2("Found dynamic symbol %s() at %s", line_func, line_pos);
- e->bt_strings[i] = bprintf("** In %s() at %s", line_func,line_pos);
- } else {
- /* damn, nothing to do here. Let's print the raw address */
- DEBUG1("Dynamic symbol not found. Raw address = %s", backtrace[i]);
- e->bt_strings[i] = bprintf("** In ?? at %s", backtrace[i]);
- }
-
- }
- free(addrs[i]);
-
- /* Mask the bottom of the stack */
- if (!strncmp("main",line_func,strlen("main")) ||
- !strncmp("xbt_thread_context_wrapper",line_func,strlen("xbt_thread_context_wrapper"))) {
- int j;
- for (j=i+1; j<e->used; j++)
- free(addrs[j]);
- e->used = i;
-
- if (!strncmp("xbt_thread_context_wrapper",line_func,strlen("xbt_thread_context_wrapper"))) {
- e->used++;
- e->bt_strings[i] = bprintf("** (in a separate thread)");
- }
- }
-
-
- }
- pclose(pipe);
- free(addrs);
- free(backtrace);
- free(cmd);
