gprof.c

早期freebsd实现

	    /*
	     *	add this arc
	     */
	tally( &arc );
    }
    fclose(pfile);
}

FILE *
openpfile(filename)
    char *filename;
{
    struct gmonhdr	tmp;
    FILE		*pfile;
    int			size;
    int			rate;

    if((pfile = fopen(filename, "r")) == NULL) {
	perror(filename);
	done();
    }
    fread(&tmp, sizeof(struct gmonhdr), 1, pfile);
    if ( s_highpc != 0 && ( tmp.lpc != gmonhdr.lpc ||
	 tmp.hpc != gmonhdr.hpc || tmp.ncnt != gmonhdr.ncnt ) ) {
	fprintf(stderr, "%s: incompatible with first gmon file\n", filename);
	done();
    }
    gmonhdr = tmp;
    if ( gmonhdr.version == GMONVERSION ) {
	rate = gmonhdr.profrate;
	size = sizeof(struct gmonhdr);
    } else {
	fseek(pfile, sizeof(struct ophdr), SEEK_SET);
	size = sizeof(struct ophdr);
	gmonhdr.profrate = rate = hertz();
	gmonhdr.version = GMONVERSION;
    }
    if (hz == 0) {
	hz = rate;
    } else if (hz != rate) {
	fprintf(stderr,
	    "%s: profile clock rate (%d) %s (%d) in first gmon file\n",
	    filename, rate, "incompatible with clock rate", hz);
	done();
    }
    s_lowpc = (unsigned long) gmonhdr.lpc;
    s_highpc = (unsigned long) gmonhdr.hpc;
    lowpc = (unsigned long)gmonhdr.lpc / sizeof(UNIT);
    highpc = (unsigned long)gmonhdr.hpc / sizeof(UNIT);
    sampbytes = gmonhdr.ncnt - size;
    nsamples = sampbytes / sizeof (UNIT);
#   ifdef DEBUG
	if ( debug & SAMPLEDEBUG ) {
	    printf( "[openpfile] hdr.lpc 0x%x hdr.hpc 0x%x hdr.ncnt %d\n",
		gmonhdr.lpc , gmonhdr.hpc , gmonhdr.ncnt );
	    printf( "[openpfile]   s_lowpc 0x%x   s_highpc 0x%x\n" ,
		s_lowpc , s_highpc );
	    printf( "[openpfile]     lowpc 0x%x     highpc 0x%x\n" ,
		lowpc , highpc );
	    printf( "[openpfile] sampbytes %d nsamples %d\n" ,
		sampbytes , nsamples );
	    printf( "[openpfile] sample rate %d\n" , hz );
	}
#   endif DEBUG
    return(pfile);
}

tally( rawp )
    struct rawarc	*rawp;
{
    nltype		*parentp;
    nltype		*childp;

    parentp = nllookup( rawp -> raw_frompc );
    childp = nllookup( rawp -> raw_selfpc );
    if ( parentp == 0 || childp == 0 )
	return;
    if ( kflag
	 && onlist( kfromlist , parentp -> name )
	 && onlist( ktolist , childp -> name ) ) {
	return;
    }
    childp -> ncall += rawp -> raw_count;
#   ifdef DEBUG
	if ( debug & TALLYDEBUG ) {
	    printf( "[tally] arc from %s to %s traversed %d times\n" ,
		    parentp -> name , childp -> name , rawp -> raw_count );
	}
#   endif DEBUG
    addarc( parentp , childp , rawp -> raw_count );
}

/*
 * dump out the gmon.sum file
 */
dumpsum( sumfile )
    char *sumfile;
{
    register nltype *nlp;
    register arctype *arcp;
    struct rawarc arc;
    FILE *sfile;

    if ( ( sfile = fopen ( sumfile , "w" ) ) == NULL ) {
	perror( sumfile );
	done();
    }
    /*
     * dump the header; use the last header read in
     */
    if ( fwrite( &gmonhdr , sizeof gmonhdr , 1 , sfile ) != 1 ) {
	perror( sumfile );
	done();
    }
    /*
     * dump the samples
     */
    if (fwrite(samples, sizeof (UNIT), nsamples, sfile) != nsamples) {
	perror( sumfile );
	done();
    }
    /*
     * dump the normalized raw arc information
     */
    for ( nlp = nl ; nlp < npe ; nlp++ ) {
	for ( arcp = nlp -> children ; arcp ; arcp = arcp -> arc_childlist ) {
	    arc.raw_frompc = arcp -> arc_parentp -> value;
	    arc.raw_selfpc = arcp -> arc_childp -> value;
	    arc.raw_count = arcp -> arc_count;
	    if ( fwrite ( &arc , sizeof arc , 1 , sfile ) != 1 ) {
		perror( sumfile );
		done();
	    }
#	    ifdef DEBUG
		if ( debug & SAMPLEDEBUG ) {
		    printf( "[dumpsum] frompc 0x%x selfpc 0x%x count %d\n" ,
			    arc.raw_frompc , arc.raw_selfpc , arc.raw_count );
		}
#	    endif DEBUG
	}
    }
    fclose( sfile );
}

valcmp(p1, p2)
    nltype *p1, *p2;
{
    if ( p1 -> value < p2 -> value ) {
	return LESSTHAN;
    }
    if ( p1 -> value > p2 -> value ) {
	return GREATERTHAN;
    }
    return EQUALTO;
}

readsamples(pfile)
    FILE	*pfile;
{
    register i;
    UNIT	sample;
    
    if (samples == 0) {
	samples = (UNIT *) calloc(sampbytes, sizeof (UNIT));
	if (samples == 0) {
	    fprintf( stderr , "%s: No room for %d sample pc's\n", 
		whoami , sampbytes / sizeof (UNIT));
	    done();
	}
    }
    for (i = 0; i < nsamples; i++) {
	fread(&sample, sizeof (UNIT), 1, pfile);
	if (feof(pfile))
		break;
	samples[i] += sample;
    }
    if (i != nsamples) {
	fprintf(stderr,
	    "%s: unexpected EOF after reading %d/%d samples\n",
		whoami , --i , nsamples );
	done();
    }
}

/*
 *	Assign samples to the procedures to which they belong.
 *
 *	There are three cases as to where pcl and pch can be
 *	with respect to the routine entry addresses svalue0 and svalue1
 *	as shown in the following diagram.  overlap computes the
 *	distance between the arrows, the fraction of the sample
 *	that is to be credited to the routine which starts at svalue0.
 *
 *	    svalue0                                         svalue1
 *	       |                                               |
 *	       v                                               v
 *
 *	       +-----------------------------------------------+
 *	       |					       |
 *	  |  ->|    |<-		->|         |<-		->|    |<-  |
 *	  |         |		  |         |		  |         |
 *	  +---------+		  +---------+		  +---------+
 *
 *	  ^         ^		  ^         ^		  ^         ^
 *	  |         |		  |         |		  |         |
 *	 pcl       pch		 pcl       pch		 pcl       pch
 *
 *	For the vax we assert that samples will never fall in the first
 *	two bytes of any routine, since that is the entry mask,
 *	thus we give call alignentries() to adjust the entry points if
 *	the entry mask falls in one bucket but the code for the routine
 *	doesn't start until the next bucket.  In conjunction with the
 *	alignment of routine addresses, this should allow us to have
 *	only one sample for every four bytes of text space and never
 *	have any overlap (the two end cases, above).
 */
asgnsamples()
{
    register int	j;
    UNIT		ccnt;
    double		time;
    unsigned long	pcl, pch;
    register int	i;
    unsigned long	overlap;
    unsigned long	svalue0, svalue1;

    /* read samples and assign to namelist symbols */
    scale = highpc - lowpc;
    scale /= nsamples;
    alignentries();
    for (i = 0, j = 1; i < nsamples; i++) {
	ccnt = samples[i];
	if (ccnt == 0)
		continue;
	pcl = lowpc + scale * i;
	pch = lowpc + scale * (i + 1);
	time = ccnt;
#	ifdef DEBUG
	    if ( debug & SAMPLEDEBUG ) {
		printf( "[asgnsamples] pcl 0x%x pch 0x%x ccnt %d\n" ,
			pcl , pch , ccnt );
	    }
#	endif DEBUG
	totime += time;
	for (j = j - 1; j < nname; j++) {
	    svalue0 = nl[j].svalue;
	    svalue1 = nl[j+1].svalue;
		/*
		 *	if high end of tick is below entry address, 
		 *	go for next tick.
		 */
	    if (pch < svalue0)
		    break;
		/*
		 *	if low end of tick into next routine,
		 *	go for next routine.
		 */
	    if (pcl >= svalue1)
		    continue;
	    overlap = min(pch, svalue1) - max(pcl, svalue0);
	    if (overlap > 0) {
#		ifdef DEBUG
		    if (debug & SAMPLEDEBUG) {
			printf("[asgnsamples] (0x%x->0x%x-0x%x) %s gets %f ticks %d overlap\n",
				nl[j].value/sizeof(UNIT), svalue0, svalue1,
				nl[j].name, 
				overlap * time / scale, overlap);
		    }
#		endif DEBUG
		nl[j].time += overlap * time / scale;
	    }
	}
    }
#   ifdef DEBUG
	if (debug & SAMPLEDEBUG) {
	    printf("[asgnsamples] totime %f\n", totime);
	}
#   endif DEBUG
}


unsigned long
min(a, b)
    unsigned long a,b;
{
    if (a<b)
	return(a);
    return(b);
}

unsigned long
max(a, b)
    unsigned long a,b;
{
    if (a>b)
	return(a);
    return(b);
}

    /*
     *	calculate scaled entry point addresses (to save time in asgnsamples),
     *	and possibly push the scaled entry points over the entry mask,
     *	if it turns out that the entry point is in one bucket and the code
     *	for a routine is in the next bucket.
     */
alignentries()
{
    register struct nl	*nlp;
    unsigned long	bucket_of_entry;
    unsigned long	bucket_of_code;

    for (nlp = nl; nlp < npe; nlp++) {
	nlp -> svalue = nlp -> value / sizeof(UNIT);
	bucket_of_entry = (nlp->svalue - lowpc) / scale;
	bucket_of_code = (nlp->svalue + UNITS_TO_CODE - lowpc) / scale;
	if (bucket_of_entry < bucket_of_code) {
#	    ifdef DEBUG
		if (debug & SAMPLEDEBUG) {
		    printf("[alignentries] pushing svalue 0x%x to 0x%x\n",
			    nlp->svalue, nlp->svalue + UNITS_TO_CODE);
		}
#	    endif DEBUG
	    nlp->svalue += UNITS_TO_CODE;
	}
    }
}

bool
funcsymbol( nlistp )
    struct nlist	*nlistp;
{
    extern char	*strtab;	/* string table from a.out */
    extern int	aflag;		/* if static functions aren't desired */
    char	*name, c;

	/*
	 *	must be a text symbol,
	 *	and static text symbols don't qualify if aflag set.
	 */
    if ( ! (  ( nlistp -> n_type == ( N_TEXT | N_EXT ) )
	   || ( ( nlistp -> n_type == N_TEXT ) && ( aflag == 0 ) ) ) ) {
	return FALSE;
    }
	/*
	 *	can't have any `funny' characters in name,
	 *	where `funny' includes	`.', .o file names
	 *			and	`$', pascal labels.
	 *	need to make an exception for sparc .mul & co.
	 *	perhaps we should just drop this code entirely...
	 */
    name = strtab + nlistp -> n_un.n_strx;
#ifdef sparc
    if ( *name == '.' ) {
	char *p = name + 1;
	if ( *p == 'u' )
	    p++;
	if ( strcmp ( p, "mul" ) == 0 || strcmp ( p, "div" ) == 0 ||
	     strcmp ( p, "rem" ) == 0 )
		return TRUE;
    }
#endif
    while ( c = *name++ ) {
	if ( c == '.' || c == '$' ) {
	    return FALSE;
	}
    }
    return TRUE;
}

done()
{

    exit(0);
}