/*
  Copyright (C) 1999 by Juergen Pfeifer <juergen.pfeifer@gmx.net>
  Ada for Linux Team (ALT)

  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the
  "Software"), to deal in the Software without restriction, including
  without limitation the rights to use, copy, modify, merge, publish,
  distribute, distribute with modifications, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included
  in all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
  THE USE OR OTHER DEALINGS IN THE SOFTWARE.

  Except as contained in this notice, the name(s) of the above copyright
  holders shall not be used in advertising or otherwise to promote the
  sale, use or other dealings in this Software without prior written
  authorization.
*/
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>

#define STDIN_FILENO  0
#define STDOUT_FILENO 1
#define MAX_LINE      1024

#define CLOSE1  close(fd1[0]); close(fd1[1])
#define CLOSE2  close(fd2[0]); close(fd2[1])
#define RESTSIG sigaction(SIGPIPE,&oact,NULL)

void convert_addresses
( const char* filename,
  void* addrs[],
  int   n_addr,
  char* buf,
  int*  len)
{
  int max_len = *len;
  pid_t pid = getpid();
  pid_t child;

  struct sigaction act, oact;

  int fd1[2], fd2[2];
  char exe_name[128];

  *buf = 0; *len = 0;
  /* Thanx to the /proc filesystem we can very easily reference our own
     executable image:-)*/
  snprintf(exe_name,sizeof(exe_name),"--exe=/proc/%ld/exe", (long)pid);

  act.sa_handler = SIG_IGN;
  sigemptyset(&act.sa_mask);
  act.sa_flags = 0;
  if (sigaction(SIGPIPE,&act,&oact) < 0)
    return;

  if (pipe(fd1) >= 0) {
    if (pipe(fd2)>=0) {
      if ((child = fork()) < 0) {
      CLOSE1; CLOSE2; RESTSIG;
      return;
      }
      else {
      if (0==child) {
        close(fd1[1]);
        close(fd2[0]);
        if (fd1[0] != STDIN_FILENO) {
          if (dup2(fd1[0],STDIN_FILENO) != STDIN_FILENO) {
            CLOSE1; CLOSE2;
          }
          close(fd1[0]);
        }
        if (fd2[1] != STDOUT_FILENO) {
          if (dup2(fd2[1],STDOUT_FILENO) != STDOUT_FILENO) {
            CLOSE1; CLOSE2;
          }
          close(fd2[1]);
        }
        {
          /* As pointed out by Florian Weimer to me, it is a
             security threat to call the script with a user defined
             environment and using the path. That would be Trojans
             pleasure.  Therefore we use the absolute path to
             addr2line and an empty environment. That should be
             safe.
          */
          char *const argv[] = { "addr2line",
                                 exe_name,
                                 "--demangle=gnat",
                                 "--functions",
                                 "--basenames",
                                 NULL };
          char *const envp[] = { NULL };
          if (execve("/usr/bin/addr2line", argv, envp) < 0) {
            CLOSE1; CLOSE2;
          }
        }
      }
      else {
        int i, n;
        char hex[16];
        char line[MAX_LINE + 1];
        char *p;
        char *s = buf;

        /* Parent context */
        close(fd1[0]);
        close(fd2[1]);

        for(i=0; i < n_addr; i++) {
          snprintf(hex,sizeof(hex),"%p\n",addrs[i]);
          write(fd1[1],hex,strlen(hex));
          n = read(fd2[0],line,MAX_LINE);
          if (n<=0)
            break;
          line[n]=0;
          /* We have approx. 16 additional chars for "%p in " clause.
             We use this info to prevent a buffer overrun.
          */
          if (n + 16 + (*len) > max_len)
            break;
          p = strchr(line,'\n');
          if (p) {
            if (*(p+1)) {
              *p = 0;
              *len += snprintf(s, (max_len - (*len)), "%p in %s at %s",addrs[i], line, p+1);
            }
            else {
              *len += snprintf(s, (max_len - (*len)), "%p at %s",addrs[i], line);
            }
            s = buf + (*len);
          }
        }
        close(fd1[1]);
        close(fd2[0]);
      }
      }
    }
    else {
      CLOSE1;
    }
  }
  RESTSIG;
}