view rvinterf/ctracedec/decode.c @ 461:10e168596dfd

doc/SIM-hardware-debugging: article written
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 10 Feb 2019 20:40:56 +0000
parents e7502631a0f9
children
line wrap: on
line source

/*
 * This module implements the actual decoding of compressed traces.
 */

#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>

extern char *str2ind_tab_filename;
extern int str2ind_array_size;
extern char **str2ind_orig_strings;
extern char **str2ind_param_strings;

#define	MAX_PRINTF_PARAMS	16

static int cindex, cindex_nchars;
static u_char param_bytes_array[256];
static int param_bytes_count;
static char *format_string, *param_type_string;
static int num_printf_params;
static u_long printf_params[MAX_PRINTF_PARAMS];
static char output_buf[2048];

decode_hex_digit(c)
{
	if (isdigit(c))
		return(c - '0');
	else if (isupper(c))
		return(c - 'A' + 10);
	else
		return(c - 'a' + 10);
}

static int
decode_idx_and_params(line)
	char *line;
{
	char *cp;
	u_char *dp;

	for (cp = line; isdigit(*cp); cp++)
		;
	if (*cp && *cp != ' ')
		return(-1);
	cindex = atoi(line);
	cindex_nchars = cp - line;
	for (dp = param_bytes_array; *cp; ) {
		if (*cp++ != ' ')
			return(-1);
		if (!isxdigit(cp[0]) || !isxdigit(cp[1]))
			return(-1);
		*dp++ = decode_hex_digit(cp[0]) << 4 | decode_hex_digit(cp[1]);
		cp += 2;
	}
	param_bytes_count = dp - param_bytes_array;
	return(0);
}

static void
decode_parameters(filename_for_errs, lineno_for_errs)
	char *filename_for_errs;
{
	int pi, type;
	u_char *bp, *endp;

	bp = param_bytes_array;
	endp = bp + param_bytes_count;
	for (pi = 0; pi < num_printf_params; pi++) {
		type = param_type_string[pi];
		switch (type) {
		case 'c':
			if (bp >= endp) {
wrong_param_byte_count:		fprintf(stderr,
	"%s line %d: wrong number of parameter bytes for %s entry #%d\n",
					filename_for_errs, lineno_for_errs,
					str2ind_tab_filename, cindex);
				exit(1);
			}
			printf_params[pi] = *bp++;
			continue;
		case 'i':
		case 'p':
		case '*':
			if (bp > endp - 4)
				goto wrong_param_byte_count;
			printf_params[pi] = (u_long) bp[0] |
					    (u_long) bp[1] << 8 |
					    (u_long) bp[2] << 16 |
					    (u_long) bp[3] << 24;
			bp += 4;
			continue;
		case 's':
			printf_params[pi] = (u_long) bp;
			for (;;) {
				if (bp >= endp) {
					fprintf(stderr,
	"%s line %d: unterminated string parameter in compressed trace\n",
						filename_for_errs,
						lineno_for_errs);
					exit(1);
				}
				if (!*bp++)
					break;
			}
			continue;
		default:
			fprintf(stderr,
			"%s entry #%d: parameter type \'%c\' not supported\n",
				str2ind_tab_filename, cindex, type);
			exit(1);
		}
	}
	if (bp != endp)
		goto wrong_param_byte_count;
}

process_ctrace_line(line, cindex_offset, filename_for_errs, lineno_for_errs)
	char *line, *filename_for_errs;
{
	if (decode_idx_and_params(line + cindex_offset) < 0) {
		fprintf(stderr,
			"%s line %d: unable to decode compressed trace line\n",
			filename_for_errs, lineno_for_errs);
		exit(1);
	}
	if (cindex >= str2ind_array_size) {
		fprintf(stderr,
			"%s line %d: index %d exceeds the range of %s\n",
			filename_for_errs, lineno_for_errs, cindex,
			str2ind_tab_filename);
		exit(1);
	}
	format_string = str2ind_orig_strings[cindex];
	param_type_string = str2ind_param_strings[cindex];
	num_printf_params = strlen(param_type_string);
	if (num_printf_params > MAX_PRINTF_PARAMS) {
		fprintf(stderr,
			"error: entry #%d in %s has too many parameters\n",
			cindex, str2ind_tab_filename);
		exit(1);
	}
	decode_parameters(filename_for_errs, lineno_for_errs);
	ind2str_doprnt(format_string, printf_params, output_buf);
	printf("%.*s \"%s\"\n", cindex_offset + cindex_nchars, line,
		output_buf);
	return(0);
}