pjs/tools/reorder/histogram.cpp

143 строки
3.1 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
A program that computes a call histogram from runtime call
information. It reads a list of address references (e.g., as
computed by libcygprof.so), and uses an ELF image to map the
addresses to functions.
*/
#include <fstream>
#include <hash_map>
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include "elf_symbol_table.h"
#define _GNU_SOURCE
#include <getopt.h>
const char *opt_exe;
int opt_tick = 0;
elf_symbol_table table;
typedef hash_map<unsigned int, unsigned int> histogram_t;
histogram_t histogram;
static struct option long_options[] = {
{ "exe", required_argument, 0, 'e' },
{ "tick", optional_argument, 0, 't' },
{ 0, 0, 0, 0 }
};
static void
usage(const char *name)
{
cerr << "usage: " << name << " --exe=<image> [--tick[=count]]" << endl;
}
static void
map_addrs(int fd)
{
// Read the binary addresses from stdin.
unsigned int buf[128];
ssize_t cb;
unsigned int count = 0;
while ((cb = read(fd, buf, sizeof buf)) > 0) {
if (cb % sizeof buf[0])
fprintf(stderr, "unaligned read\n");
unsigned int *addr = buf;
unsigned int *limit = buf + (cb / 4);
for (; addr < limit; ++addr) {
const Elf32_Sym *sym = table.lookup(*addr);
if (sym)
++histogram[reinterpret_cast<unsigned int>(sym)];
if (opt_tick && (++count % opt_tick == 0)) {
cerr << ".";
flush(cerr);
}
}
}
if (opt_tick)
cerr << endl;
}
int
main(int argc, char *argv[])
{
int c;
while (1) {
int option_index = 0;
c = getopt_long(argc, argv, "e:t", long_options, &option_index);
if (c < 0)
break;
switch (c) {
case 'e':
opt_exe = optarg;
break;
case 't':
opt_tick = optarg ? atoi(optarg) : 1000000;
break;
default:
usage(argv[0]);
return 1;
}
}
if (! opt_exe) {
usage(argv[0]);
return 1;
}
table.init(opt_exe);
// Process addresses.
if (optind >= argc) {
map_addrs(STDIN_FILENO);
}
else {
do {
int fd = open(argv[optind], O_RDONLY);
if (fd < 0) {
perror(argv[optind]);
return 1;
}
map_addrs(fd);
close(fd);
} while (++optind < argc);
}
// Emit the histogram.
histogram_t::const_iterator limit = histogram.end();
histogram_t::const_iterator i;
for (i = histogram.begin(); i != limit; ++i) {
const Elf32_Sym *sym = reinterpret_cast<const Elf32_Sym *>(i->first);
cout.form("%08x %6d %2d %10d ",
sym->st_value,
sym->st_size,
sym->st_shndx,
i->second);
cout << table.get_symbol_name(sym) << endl;
}
return 0;
}