/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. [rescinded 22 July 1999]
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * This is a modified gmon.c by J.W.Hawtin <oolon@ankh.org>,
 * 14/8/96 based on the original gmon.c in GCC and the hacked version
 * solaris 2 sparc version (config/sparc/gmon-sol.c) by Mark Eichin. To do
 * process profiling on solaris 2.X X86
 *
 * It must be used in conjunction with sol2-gc1.asm, which is used to start
 * and stop process monitoring.
 *
 * Differences.
 *
 * On Solaris 2 _mcount is called by library functions not mcount, so support
 * has been added for both.
 *
 * Also the prototype for profil() is different
 *
 * Solaris 2 does not seem to have char *minbrk whcih allows the setting of
 * the minimum SBRK region so this code has been removed and lets pray malloc
 * does not mess it up.
 *
 * Notes
 *
 * This code could easily be integrated with the original gmon.c and perhaps
 * should be.
 */
#include "tconfig.h"
#include "tsystem.h"
#include <fcntl.h> /* for creat() */

#ifdef DEBUG
#include <stdio.h>
#endif

static void moncontrol (int);
extern void monstartup (char *, char *);
extern void _mcleanup (void);
extern void internal_mcount (void);


struct phdr {
                char    *lpc;
                char    *hpc;
                int     ncnt;
};


#define HISTFRACTION 2
#define HISTCOUNTER unsigned short
#define HASHFRACTION 1
#define ARCDENSITY 2
#define MINARCS 50
#define BASEADDRESS 0x8000000 /* On Solaris 2 X86 all executables start here
                                 and not at 0 */ 

struct tostruct {
  char *selfpc;
  long count;
  unsigned short link;
};

struct rawarc {
    unsigned long       raw_frompc;
    unsigned long       raw_selfpc;
    long                raw_count;
};
#define ROUNDDOWN(x,y)  (((x)/(y))*(y))
#define ROUNDUP(x,y)    ((((x)+(y)-1)/(y))*(y))

/* char *minbrk; */

    /*
     *        froms is actually a bunch of unsigned shorts indexing tos
     */
static int                profiling = 3;
static unsigned short        *froms;
static struct tostruct        *tos = 0;
static long                tolimit = 0;
static char                *s_lowpc = 0;
static char                *s_highpc = 0;
static unsigned long        s_textsize = 0;

static int        ssiz;
static char        *sbuf;
static int        s_scale;
    /* see profil(2) where this is describe (incorrectly) */
#define                SCALE_1_TO_1        0x10000L

#define        MSG "No space for profiling buffer(s)\n"

extern int errno;

void
monstartup(char *lowpc, char *highpc)
{
    int                        monsize;
    char                *buffer;
    register int        o;

        /*
         *        round lowpc and highpc to multiples of the density we're using
         *        so the rest of the scaling (here and in gprof) stays in ints.
         */
    lowpc = (char *)
            ROUNDDOWN((unsigned long)lowpc, HISTFRACTION*sizeof(HISTCOUNTER));
    s_lowpc = lowpc;
    highpc = (char *)
            ROUNDUP((unsigned long)highpc, HISTFRACTION*sizeof(HISTCOUNTER));
    s_highpc = highpc;
    s_textsize = highpc - lowpc;
    monsize = (s_textsize / HISTFRACTION) + sizeof(struct phdr);
    buffer = (char *) sbrk( monsize );
    if ( buffer == (char *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        return;
    }
    froms = (unsigned short *) sbrk( s_textsize / HASHFRACTION );
    if ( froms == (unsigned short *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        return;
    }
    tolimit = s_textsize * ARCDENSITY / 100;
    if ( tolimit < MINARCS ) {
        tolimit = MINARCS;
    } else if ( tolimit > 65534 ) {
        tolimit = 65534;
    }
    tos = (struct tostruct *) sbrk( tolimit * sizeof( struct tostruct ) );
    if ( tos == (struct tostruct *) -1 ) {
        write( 2 , MSG , sizeof(MSG) );
        froms = 0;
        tos = 0;
        return;
    }
/*    minbrk = (char *) sbrk(0);*/
    tos[0].link = 0;
    sbuf = buffer;
    ssiz = monsize;
    ( (struct phdr *) buffer ) -> lpc = lowpc;
    ( (struct phdr *) buffer ) -> hpc = highpc;
    ( (struct phdr *) buffer ) -> ncnt = ssiz;
    monsize -= sizeof(struct phdr);
    if ( monsize <= 0 )
        return;
    o = highpc - lowpc;
    if( monsize < o )
#ifndef hp300
        s_scale = ( (float) monsize / o ) * SCALE_1_TO_1;
#else /* avoid floating point */
    {
        int quot = o / monsize;

        if (quot >= 0x10000)
                s_scale = 1;
        else if (quot >= 0x100)
                s_scale = 0x10000 / quot;
        else if (o >= 0x800000)
                s_scale = 0x1000000 / (o / (monsize >> 8));
        else
                s_scale = 0x1000000 / ((o << 8) / monsize);
    }
#endif
    else
        s_scale = SCALE_1_TO_1;
    moncontrol(1);
}

void
_mcleanup (void)
{
    int                        fd;
    int                        fromindex;
    int                        endfrom;
    char                *frompc;
    int                        toindex;
    struct rawarc        rawarc;

    moncontrol(0);
    fd = creat( "gmon.out" , 0666 );
    if ( fd < 0 ) {
        perror( "mcount: gmon.out" );
        return;
    }
#   ifdef DEBUG
        fprintf( stderr , "[mcleanup] sbuf 0x%x ssiz %d\n" , sbuf , ssiz );
#   endif /* DEBUG */

    write( fd , sbuf , ssiz );
    endfrom = s_textsize / (HASHFRACTION * sizeof(*froms));
    for ( fromindex = 0 ; fromindex < endfrom ; fromindex++ ) {
        if ( froms[fromindex] == 0 ) {
            continue;
        }
        frompc = s_lowpc + (fromindex * HASHFRACTION * sizeof(*froms));
        for (toindex=froms[fromindex]; toindex!=0; toindex=tos[toindex].link) {
#            ifdef DEBUG
                fprintf( stderr ,
                        "[mcleanup] frompc 0x%x selfpc 0x%x count %d\n" ,
                        frompc , tos[toindex].selfpc , tos[toindex].count );
#            endif /* DEBUG */
            rawarc.raw_frompc = (unsigned long) frompc;
            rawarc.raw_selfpc = (unsigned long) tos[toindex].selfpc;
            rawarc.raw_count = tos[toindex].count;
            write( fd , &rawarc , sizeof rawarc );
        }
    }
    close( fd );
}

/* Solaris 2 libraries use _mcount.  */
asm(".globl _mcount; _mcount: jmp internal_mcount");
/* This is for compatibility with old versions of gcc which used mcount.  */
asm(".globl mcount; mcount: jmp internal_mcount");

void
internal_mcount (void)
{
        register char                        *selfpc;
        register unsigned short                *frompcindex;
        register struct tostruct        *top;
        register struct tostruct        *prevtop;
        register long                        toindex;
        static char already_setup;

        /*
         *        find the return address for mcount,
         *        and the return address for mcount's caller.
         */

        /* selfpc = pc pushed by mcount call.
           This identifies the function that was just entered.  */
        selfpc = (void *) __builtin_return_address (0);
        /* frompcindex = pc in preceding frame.
           This identifies the caller of the function just entered.  */
        frompcindex = (void *) __builtin_return_address (1);

        if(!already_setup) {
          extern char etext[];
          already_setup = 1;
/*          monstartup(0, etext); */
          monstartup((char*)0x08040000, etext);
#ifdef USE_ONEXIT
          on_exit(_mcleanup, 0);
#else
          atexit(_mcleanup);
#endif
        }
        /*
         *        check that we are profiling
         *        and that we aren't recursively invoked.
         */
        if (profiling) {
                goto out;
        }
        profiling++;
        /*
         *        check that frompcindex is a reasonable pc value.
         *        for example:        signal catchers get called from the stack,
         *                        not from text space.  too bad.
         */
        frompcindex = (unsigned short *)((long)frompcindex - (long)s_lowpc);
        if ((unsigned long)frompcindex > s_textsize) {
                goto done;
        }
        frompcindex =
            &froms[((long)frompcindex) / (HASHFRACTION * sizeof(*froms))];
        toindex = *frompcindex;
        if (toindex == 0) {
                /*
                 *        first time traversing this arc
                 */
                toindex = ++tos[0].link;
                if (toindex >= tolimit) {
                        goto overflow;
                }
                *frompcindex = toindex;
                top = &tos[toindex];
                top->selfpc = selfpc;
                top->count = 1;
                top->link = 0;
                goto done;
        }
        top = &tos[toindex];
        if (top->selfpc == selfpc) {
                /*
                 *        arc at front of chain; usual case.
                 */
                top->count++;
                goto done;
        }
        /*
         *        have to go looking down chain for it.
         *        top points to what we are looking at,
         *        prevtop points to previous top.
         *        we know it is not at the head of the chain.
         */
        for (; /* goto done */; ) {
                if (top->link == 0) {
                        /*
                         *        top is end of the chain and none of the chain
                         *        had top->selfpc == selfpc.
                         *        so we allocate a new tostruct
                         *        and link it to the head of the chain.
                         */
                        toindex = ++tos[0].link;
                        if (toindex >= tolimit) {
                                goto overflow;
                        }
                        top = &tos[toindex];
                        top->selfpc = selfpc;
                        top->count = 1;
                        top->link = *frompcindex;
                        *frompcindex = toindex;
                        goto done;
                }
                /*
                 *        otherwise, check the next arc on the chain.
                 */
                prevtop = top;
                top = &tos[top->link];
                if (top->selfpc == selfpc) {
                        /*
                         *        there it is.
                         *        increment its count
                         *        move it to the head of the chain.
                         */
                        top->count++;
                        toindex = prevtop->link;
                        prevtop->link = top->link;
                        top->link = *frompcindex;
                        *frompcindex = toindex;
                        goto done;
                }

        }
done:
        profiling--;
        /* and fall through */
out:
        return;                /* normal return restores saved registers */

overflow:
        profiling++; /* halt further profiling */
#   define        TOLIMIT        "mcount: tos overflow\n"
        write(2, TOLIMIT, sizeof(TOLIMIT));
        goto out;
}

/*
 * Control profiling
 *        profiling is what mcount checks to see if
 *        all the data structures are ready.
 */
static void
moncontrol(int mode)
{
    if (mode)
    {
      /* start */
      profil((unsigned short *)(sbuf + sizeof(struct phdr)),
             ssiz - sizeof(struct phdr),
             (long)s_lowpc, s_scale);
      
      profiling = 0;
    } else {
      /* stop */
      profil((unsigned short *)0, 0, 0, 0);
      profiling = 3;
    }
}