libgcc2.c

GCC编译器源代码

#include <string.h>

/* Number of buckets in hashtable of basic block addresses.  */

#define BB_BUCKETS 311

/* Maximum length of string in file bb.in.  */

#define BBINBUFSIZE 500

/* BBINBUFSIZE-1 with double quotes. We could use #BBINBUFSIZE or
   "BBINBUFSIZE" but want to avoid trouble with preprocessors.  */

#define BBINBUFSIZESTR "499"

struct bb_edge
{
  struct bb_edge *next;
  unsigned long src_addr;
  unsigned long dst_addr;
  unsigned long count;
};

enum bb_func_mode
{
  TRACE_KEEP = 0, TRACE_ON = 1, TRACE_OFF = 2
};

struct bb_func
{
  struct bb_func *next;
  char *funcname;
  char *filename;
  enum bb_func_mode mode;
};

/* This is the connection to the outside world.
   The BLOCK_PROFILER macro must set __bb.blocks
   and __bb.blockno.  */

struct {
  unsigned long blockno;
  struct bb *blocks;
} __bb;

/* Vars to store addrs of source and destination basic blocks 
   of a jump.  */

static unsigned long bb_src = 0;
static unsigned long bb_dst = 0;

static FILE *bb_tracefile = (FILE *) 0;
static struct bb_edge **bb_hashbuckets = (struct bb_edge **) 0;
static struct bb_func *bb_func_head = (struct bb_func *) 0;
static unsigned long bb_callcount = 0;
static int bb_mode = 0;

static unsigned long *bb_stack = (unsigned long *) 0;
static size_t bb_stacksize = 0;

static int reported = 0;

/* Trace modes:
Always             :   Print execution frequencies of basic blocks
                       to file bb.out.
bb_mode & 1 != 0   :   Dump trace of basic blocks to file bbtrace[.gz]
bb_mode & 2 != 0   :   Print jump frequencies to file bb.out.
bb_mode & 4 != 0   :   Cut call instructions from basic block flow.
bb_mode & 8 != 0   :   Insert return instructions in basic block flow.
*/

#ifdef HAVE_POPEN

/*#include <sys/types.h>*/
#include <sys/stat.h>
/*#include <malloc.h>*/

/* Commands executed by gopen.  */

#define GOPENDECOMPRESS "gzip -cd "
#define GOPENCOMPRESS "gzip -c >"

/* Like fopen but pipes through gzip.  mode may only be "r" or "w".
   If it does not compile, simply replace gopen by fopen and delete
   '.gz' from any first parameter to gopen.  */

static FILE *
gopen (char *fn, char *mode)
{
  int use_gzip;
  char *p;

  if (mode[1])
    return (FILE *) 0;

  if (mode[0] != 'r' && mode[0] != 'w') 
    return (FILE *) 0;

  p = fn + strlen (fn)-1;
  use_gzip = ((p[-1] == '.' && (p[0] == 'Z' || p[0] == 'z'))
	      || (p[-2] == '.' && p[-1] == 'g' && p[0] == 'z'));

  if (use_gzip)
    {
      if (mode[0]=='r')
        {
          FILE *f;
          char *s = (char *) malloc (sizeof (char) * strlen (fn)
				     + sizeof (GOPENDECOMPRESS));
          strcpy (s, GOPENDECOMPRESS);
          strcpy (s + (sizeof (GOPENDECOMPRESS)-1), fn);
          f = popen (s, mode);
          free (s);
          return f;
        }

      else
        {
          FILE *f;
          char *s = (char *) malloc (sizeof (char) * strlen (fn)
				     + sizeof (GOPENCOMPRESS));
          strcpy (s, GOPENCOMPRESS);
          strcpy (s + (sizeof (GOPENCOMPRESS)-1), fn);
          if (!(f = popen (s, mode)))
            f = fopen (s, mode);
          free (s);
          return f;
        }
    }

  else
    return fopen (fn, mode);
}

static int
gclose (FILE *f)
{
  struct stat buf;

  if (f != 0)
    {
      if (!fstat (fileno (f), &buf) && S_ISFIFO (buf.st_mode))
        return pclose (f);

      return fclose (f);
    }
  return 0;
}

#endif /* HAVE_POPEN */

/* Called once per program.  */

static void
__bb_exit_trace_func ()
{
  FILE *file = fopen ("bb.out", "a");
  struct bb_func *f;
  struct bb_edge *e;
  struct bb *b;
        
  if (!file)
    perror ("bb.out");

  if (bb_mode & 1)
    {
      if (!bb_tracefile)
        perror ("bbtrace");
      else
#ifdef HAVE_POPEN
        gclose (bb_tracefile);
#else
        fclose (bb_tracefile);
#endif /* HAVE_POPEN */
    }

  /* Check functions in `bb.in'.  */

  if (file)
    {
      long time_value;
      const struct bb_func *p;
      int printed_something = 0;
      struct bb *ptr;
      long blk;

      /* This is somewhat type incorrect.  */
      time ((void *) &time_value);

      for (p = bb_func_head; p != (struct bb_func *) 0; p = p->next)
        {
          for (ptr = bb_head; ptr != (struct bb *) 0; ptr = ptr->next)
            {
              if (!ptr->filename || p->filename != (char *) 0 && strcmp (p->filename, ptr->filename))
                continue;
              for (blk = 0; blk < ptr->ncounts; blk++)
                {
                  if (!strcmp (p->funcname, ptr->functions[blk]))
                    goto found;
                }
            }
  
          if (!printed_something)
            {
              fprintf (file, "Functions in `bb.in' not executed during basic block profiling on %s\n", ctime ((void *) &time_value));
              printed_something = 1;
            }

          fprintf (file, "\tFunction %s", p->funcname);
          if (p->filename)
              fprintf (file, " of file %s", p->filename);
          fprintf (file, "\n" );
  
found:        ;
        }

      if (printed_something)
       fprintf (file, "\n");

    }

  if (bb_mode & 2)
    {
      if (!bb_hashbuckets)
        {
          if (!reported)
            {
              fprintf (stderr, "Profiler: out of memory\n");
              reported = 1;
            }
          return;
        }
    
      else if (file)
        {
          long time_value;
          int i;
          unsigned long addr_max = 0;
          unsigned long cnt_max  = 0;
          int cnt_len;
          int addr_len;
    
          /* This is somewhat type incorrect, but it avoids worrying about
             exactly where time.h is included from.  It should be ok unless
             a void * differs from other pointer formats, or if sizeof (long)
             is < sizeof (time_t).  It would be nice if we could assume the
             use of rationale standards here.  */
    
          time ((void *) &time_value);
          fprintf (file, "Basic block jump tracing");

          switch (bb_mode & 12)
            {
              case 0:
                fprintf (file, " (with call)");
              break;

              case 4:
		/* Print nothing.  */
              break;

              case 8:
                fprintf (file, " (with call & ret)");
              break;

              case 12:
                fprintf (file, " (with ret)");
              break;
            }

          fprintf (file, " finished on %s\n", ctime ((void *) &time_value));
    
          for (i = 0; i < BB_BUCKETS; i++)
            {
               struct bb_edge *bucket = bb_hashbuckets[i];
               for ( ; bucket; bucket = bucket->next )
                 {
                   if (addr_max < bucket->src_addr) 
                     addr_max = bucket->src_addr;
                   if (addr_max < bucket->dst_addr) 
                     addr_max = bucket->dst_addr;
                   if (cnt_max < bucket->count) 
                     cnt_max = bucket->count;
                 }
            }
          addr_len = num_digits (addr_max, 16);
          cnt_len  = num_digits (cnt_max, 10);
    
          for ( i = 0; i < BB_BUCKETS; i++)
            {
               struct bb_edge *bucket = bb_hashbuckets[i];
               for ( ; bucket; bucket = bucket->next )
                 {
                   fprintf (file, "Jump from block 0x%.*lx to "
                                  "block 0x%.*lx executed %*d time(s)\n", 
                            addr_len, bucket->src_addr, 
                            addr_len, bucket->dst_addr, 
                            cnt_len, bucket->count);
                 }
            }
  
          fprintf (file, "\n");

        }
    }

   if (file)
     fclose (file);

   /* Free allocated memory.  */

   f = bb_func_head;
   while (f)
     {
       struct bb_func *old = f;

       f = f->next;
       if (old->funcname) free (old->funcname);
       if (old->filename) free (old->filename);
       free (old);
     }

   if (bb_stack)
     free (bb_stack);

   if (bb_hashbuckets)
     {
       int i;

       for (i = 0; i < BB_BUCKETS; i++)
         {
           struct bb_edge *old, *bucket = bb_hashbuckets[i];

           while (bucket)
             {
               old = bucket;
               bucket = bucket->next;
               free (old);
             }
         }
       free (bb_hashbuckets);
     }

   for (b = bb_head; b; b = b->next)
     if (b->flags) free (b->flags);
}

/* Called once per program.  */

static void
__bb_init_prg ()
{

  FILE *file;
  char buf[BBINBUFSIZE];
  const char *p;
  const char *pos;
  enum bb_func_mode m;

#ifdef ON_EXIT
  /* Initialize destructor.  */
  ON_EXIT (__bb_exit_func, 0);
#endif

  if (!(file = fopen ("bb.in", "r")))
    return;

  while(fscanf (file, " %" BBINBUFSIZESTR "s ", buf) != EOF)
    {
      p = buf;
      if (*p == '-') 
        { 
          m = TRACE_OFF; 
          p++; 
        }
      else 
        { 
          m = TRACE_ON; 
        }
      if (!strcmp (p, "__bb_trace__"))
        bb_mode |= 1;
      else if (!strcmp (p, "__bb_jumps__"))
        bb_mode |= 2;
      else if (!strcmp (p, "__bb_hidecall__"))
        bb_mode |= 4;
      else if (!strcmp (p, "__bb_showret__"))
        bb_mode |= 8;
      else 
        {
          struct bb_func *f = (struct bb_func *) malloc (sizeof (struct bb_func));
          if (f)
            {
              unsigned long l;
              f->next = bb_func_head;
              if (pos = strchr (p, ':'))
                {
                  if (!(f->funcname = (char *) malloc (strlen (pos+1)+1)))
                    continue;
                  strcpy (f->funcname, pos+1);
                  l = pos-p;
                  if ((f->filename = (char *) malloc (l+1)))
                    {
                      strncpy (f->filename, p, l);
                      f->filename[l] = '\0';
                    }
                  else
                    f->filename = (char *) 0;
                }
              else
                {
                  if (!(f->funcname = (char *) malloc (strlen (p)+1)))
                    continue;
                  strcpy (f->funcname, p);
                  f->filename = (char *) 0;
                }
              f->mode = m;
              bb_func_head = f;
	    }
         }
    }
  fclose (file);

#ifdef HAVE_POPEN 

  if (bb_mode & 1)
      bb_tracefile = gopen ("bbtrace.gz", "w");

#else

  if (bb_mode & 1)
      bb_tracefile = fopen ("bbtrace", "w");

#endif /* HAVE_POPEN */

  if (bb_mode & 2)
    {
      bb_hashbuckets = (struct bb_edge **) 
                   malloc (BB_BUCKETS * sizeof (struct bb_edge *));
      if (bb_hashbuckets)
        bzero ((char *) bb_hashbuckets, BB_BUCKETS);
    }

  if (bb_mode & 12)
    {
      bb_stacksize = 10;
      bb_stack = (unsigned long *) malloc (bb_stacksize * sizeof (*bb_stack));
    }

#ifdef ON_EXIT
      /* Initialize destructor.  */
      ON_EXIT (__bb_exit_trace_func, 0);
#endif

}

/* Called upon entering a basic block.  */

void
__bb_trace_func ()
{
  struct bb_edge *bucket;

  MACHINE_STATE_SAVE("1")

  if (!bb_callcount || (__bb.blocks->flags && (__bb.blocks->flags[__bb.blockno] & TRACE_OFF)))
    goto skip;

  bb_dst = __bb.blocks->addresses[__bb.blockno];
  __bb.blocks->counts[__bb.blockno]++;

  if (bb_tracefile)
    {
      fwrite (&bb_dst, sizeof (unsigned long), 1, bb_tracefile);
    }

  if (bb_hashbuckets)
    {
      struct bb_edge **startbucket, **oldnext;

      oldnext = startbucket
	= & bb_hashbuckets[ (((int) bb_src*8) ^ (int) bb_dst) % BB_BUCKETS ];
      bucket = *startbucket;

      for (bucket = *startbucket; bucket; 
           oldnext = &(bucket->next), bucket = *oldnext)
        {
          if (bucket->src_addr == bb_src
	      && bucket->dst_addr == bb_dst)
            {
              bucket->count++;
              *oldnext = bucket->next;
              bucket->next = *startbucket;
              *startbucket = bucket;
              goto ret;
            }
        }

      bucket = (struct bb_edge *) malloc (sizeof (struct bb_edge));

      if (!bucket)
        {
          if (!reported)
            {
              fprintf (stderr, "Profiler: out of memory\n");
              reported = 1;
            }
        }

      else
        {
          bucket->src_addr = bb_src;
          bucket->dst_addr = bb_dst;
          bucket->next = *startbucket;
          *startbucket = bucket;
          bucket->count = 1;
        }
    }

ret:
  bb_src = bb_dst;

skip:
  ;

  MACHINE_STATE_RESTORE("1")

}

/* Called when returning from a function and `__bb_showret__' is set.  */

static void
__bb_trace_func_ret ()
{
  struct bb_edge *bucket;

  if (!bb_callcount || (__bb.blocks->flags && (__bb.blocks->flags[__bb.blockno] & TRACE_OFF)))
    goto skip;

  if (bb_hashbuckets)
    {
      struct bb_edge **startbucket, **oldnext;

      oldnext = startbucket
	= & bb_hashbuckets[ (((int) bb_dst * 8) ^ (int) bb_src) % BB_BUCKETS ];
      bucket = *startbucket;

      for (bucket = *startbucket; bucket; 
           oldnext = &(bucket->next), bucket = *oldnext)
        {
          if (bucket->src_addr == bb_dst
	       && bucket->dst_addr == bb_src)
            {
              bucket->count++;
              *oldnext = bucket->next;
              bucket->next = *startbucket;
              *startbucket = bucket;
              goto ret;
            }
        }

      bucket = (struct bb_edge *) malloc (sizeof (struct bb_edge));

      if (!bucket)
        {
          if (!reported)
            {
              fprintf (stderr, "Profiler: out of memory\n");
              reported = 1;
            }
        }

      else
        {
          bucket->src_addr = bb_dst;
          bucket->dst_addr = bb_src;