gcc/gmon.c

   1 /*-
   2  * Copyright (c) 1991 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 static char sccsid[] = "@(#)gmon.c      5.3 (Berkeley) 5/22/91";
  36 #endif /* not lint */
  37
  38 #if 0
  39 #include <unistd.h>
  40
  41 #endif
  42 #ifdef DEBUG
  43 #include <stdio.h>
  44 #endif
  45
  46 #include "gmon.h"
  47
  48 extern mcount() asm ("mcount");
  49 extern char *minbrk asm ("minbrk");
  50
  51 #ifdef __alpha
  52 extern char *sbrk ();
  53 #endif
  54
  55     /*
  56      *  froms is actually a bunch of unsigned shorts indexing tos
  57      */
  58 static int              profiling = 3;
  59 static unsigned short   *froms;
  60 static struct tostruct  *tos = 0;
  61 static long             tolimit = 0;
  62 static char             *s_lowpc = 0;
  63 static char             *s_highpc = 0;
  64 static unsigned long    s_textsize = 0;
  65
  66 static int      ssiz;
  67 static char     *sbuf;
  68 static int      s_scale;
  69     /* see profil(2) where this is describe (incorrectly) */
  70 #define         SCALE_1_TO_1    0x10000L
  71
  72 #define MSG "No space for profiling buffer(s)\n"
  73
  74 monstartup(lowpc, highpc)
  75     char        *lowpc;
  76     char        *highpc;
  77 {
  78     int                 monsize;
  79     char                *buffer;
  80     register int        o;
  81
  82         /*
  83          *      round lowpc and highpc to multiples of the density we're using
  84          *      so the rest of the scaling (here and in gprof) stays in ints.
  85          */
  86     lowpc = (char *)
  87             ROUNDDOWN((unsigned) lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
  88     s_lowpc = lowpc;
  89     highpc = (char *)
  90             ROUNDUP((unsigned) highpc, HISTFRACTION*sizeof(HISTCOUNTER));
  91     s_highpc = highpc;
  92     s_textsize = highpc - lowpc;
  93     monsize = (s_textsize / HISTFRACTION) + sizeof(struct phdr);
  94     buffer = sbrk( monsize );
  95     if ( buffer == (char *) -1 ) {
  96         write( 2 , MSG , sizeof(MSG) );
  97         return;
  98     }
  99     froms = (unsigned short *) sbrk( s_textsize / HASHFRACTION );
 100     if ( froms == (unsigned short *) -1 ) {
 101         write( 2 , MSG , sizeof(MSG) );
 102         froms = 0;
 103         return;
 104     }
 105     tolimit = s_textsize * ARCDENSITY / 100;
 106     if ( tolimit < MINARCS ) {
 107         tolimit = MINARCS;
 108     } else if ( tolimit > 65534 ) {
 109         tolimit = 65534;
 110     }
 111     tos = (struct tostruct *) sbrk( tolimit * sizeof( struct tostruct ) );
 112     if ( tos == (struct tostruct *) -1 ) {
 113         write( 2 , MSG , sizeof(MSG) );
 114         froms = 0;
 115         tos = 0;
 116         return;
 117     }
 118     minbrk = sbrk(0);
 119     tos[0].link = 0;
 120     sbuf = buffer;
 121     ssiz = monsize;
 122     ( (struct phdr *) buffer ) -> lpc = lowpc;
 123     ( (struct phdr *) buffer ) -> hpc = highpc;
 124     ( (struct phdr *) buffer ) -> ncnt = ssiz;
 125     monsize -= sizeof(struct phdr);
 126     if ( monsize <= 0 )
 127         return;
 128     o = highpc - lowpc;
 129     if( monsize < o )
 130 #ifndef hp300
 131         s_scale = ( (float) monsize / o ) * SCALE_1_TO_1;
 132 #else /* avoid floating point */
 133     {
 134         int quot = o / monsize;
 135
 136         if (quot >= 0x10000)
 137                 s_scale = 1;
 138         else if (quot >= 0x100)
 139                 s_scale = 0x10000 / quot;
 140         else if (o >= 0x800000)
 141                 s_scale = 0x1000000 / (o / (monsize >> 8));
 142         else
 143                 s_scale = 0x1000000 / ((o << 8) / monsize);
 144     }
 145 #endif
 146     else
 147         s_scale = SCALE_1_TO_1;
 148     moncontrol(1);
 149 }
 150
 151 _mcleanup()
 152 {
 153     int                 fd;
 154     int                 fromindex;
 155     int                 endfrom;
 156     char                *frompc;
 157     int                 toindex;
 158     struct rawarc       rawarc;
 159
 160     moncontrol(0);
 161     fd = creat( "gmon.out" , 0666 );
 162     if ( fd < 0 ) {
 163         perror( "mcount: gmon.out" );
 164         return;
 165     }
 166 #   ifdef DEBUG
 167         fprintf( stderr , "[mcleanup] sbuf 0x%x ssiz %d\n" , sbuf , ssiz );
 168 #   endif DEBUG
 169     write( fd , sbuf , ssiz );
 170     endfrom = s_textsize / (HASHFRACTION * sizeof(*froms));
 171     for ( fromindex = 0 ; fromindex < endfrom ; fromindex++ ) {
 172         if ( froms[fromindex] == 0 ) {
 173             continue;
 174         }
 175         frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof(*froms));
 176         for (toindex=froms[fromindex]; toindex!=0; toindex=tos[toindex].link) {
 177 #           ifdef DEBUG
 178                 fprintf( stderr ,
 179                         "[mcleanup] frompc 0x%x selfpc 0x%x count %d\n" ,
 180                         frompc , tos[toindex].selfpc , tos[toindex].count );
 181 #           endif DEBUG
 182             rawarc.raw_frompc = (unsigned long) frompc;
 183             rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;
 184             rawarc.raw_count = tos[toindex].count;
 185             write( fd , &rawarc , sizeof rawarc );
 186         }
 187     }
 188     close( fd );
 189 }
 190
 191 mcount()
 192 {
 193         register char                   *selfpc;
 194         register unsigned short         *frompcindex;
 195         register struct tostruct        *top;
 196         register struct tostruct        *prevtop;
 197         register long                   toindex;
 198
 199         /*
 200          *      find the return address for mcount,
 201          *      and the return address for mcount's caller.
 202          */
 203
 204         /* selfpc = pc pushed by mcount call.
 205            This identifies the function that was just entered.  */
 206         selfpc = (void *) __builtin_return_address (0);
 207         /* frompcindex = pc in preceding frame.
 208            This identifies the caller of the function just entered.  */
 209         frompcindex = (void *) __builtin_return_address (1);
 210         /*
 211          *      check that we are profiling
 212          *      and that we aren't recursively invoked.
 213          */
 214         if (profiling) {
 215                 goto out;
 216         }
 217         profiling++;
 218         /*
 219          *      check that frompcindex is a reasonable pc value.
 220          *      for example:    signal catchers get called from the stack,
 221          *                      not from text space.  too bad.
 222          */
 223         frompcindex = (unsigned short *) ((long) frompcindex - (long) s_lowpc);
 224         if ((unsigned long) frompcindex > s_textsize) {
 225                 goto done;
 226         }
 227         frompcindex =
 228             &froms[((long) frompcindex) / (HASHFRACTION * sizeof(*froms))];
 229         toindex = *frompcindex;
 230         if (toindex == 0) {
 231                 /*
 232                  *      first time traversing this arc
 233                  */
 234                 toindex = ++tos[0].link;
 235                 if (toindex >= tolimit) {
 236                         goto overflow;
 237                 }
 238                 *frompcindex = toindex;
 239                 top = &tos[toindex];
 240                 top->selfpc = selfpc;
 241                 top->count = 1;
 242                 top->link = 0;
 243                 goto done;
 244         }
 245         top = &tos[toindex];
 246         if (top->selfpc == selfpc) {
 247                 /*
 248                  *      arc at front of chain; usual case.
 249                  */
 250                 top->count++;
 251                 goto done;
 252         }
 253         /*
 254          *      have to go looking down chain for it.
 255          *      top points to what we are looking at,
 256          *      prevtop points to previous top.
 257          *      we know it is not at the head of the chain.
 258          */
 259         for (; /* goto done */; ) {
 260                 if (top->link == 0) {
 261                         /*
 262                          *      top is end of the chain and none of the chain
 263                          *      had top->selfpc == selfpc.
 264                          *      so we allocate a new tostruct
 265                          *      and link it to the head of the chain.
 266                          */
 267                         toindex = ++tos[0].link;
 268                         if (toindex >= tolimit) {
 269                                 goto overflow;
 270                         }
 271                         top = &tos[toindex];
 272                         top->selfpc = selfpc;
 273                         top->count = 1;
 274                         top->link = *frompcindex;
 275                         *frompcindex = toindex;
 276                         goto done;
 277                 }
 278                 /*
 279                  *      otherwise, check the next arc on the chain.
 280                  */
 281                 prevtop = top;
 282                 top = &tos[top->link];
 283                 if (top->selfpc == selfpc) {
 284                         /*
 285                          *      there it is.
 286                          *      increment its count
 287                          *      move it to the head of the chain.
 288                          */
 289                         top->count++;
 290                         toindex = prevtop->link;
 291                         prevtop->link = top->link;
 292                         top->link = *frompcindex;
 293                         *frompcindex = toindex;
 294                         goto done;
 295                 }
 296
 297         }
 298 done:
 299         profiling--;
 300         /* and fall through */
 301 out:
 302         return;         /* normal return restores saved registers */
 303
 304 overflow:
 305         profiling++; /* halt further profiling */
 306 #   define      TOLIMIT "mcount: tos overflow\n"
 307         write(2, TOLIMIT, sizeof(TOLIMIT));
 308         goto out;
 309 }
 310
 311 /* Control profiling
 312         profiling is what mcount checks to see if
 313         all the data structures are ready.  */
 314
 315 moncontrol(mode)
 316     int mode;
 317 {
 318     if (mode) {
 319         /* start */
 320         profil(sbuf + sizeof(struct phdr), ssiz - sizeof(struct phdr),
 321                 (int)s_lowpc, s_scale);
 322         profiling = 0;
 323     } else {
 324         /* stop */
 325         profil((char *) 0, 0, 0, 0);
 326         profiling = 3;
 327     }
 328 }
 329