gecko/tools/jprof/bfd.cpp

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// vim:ts=8:sw=2:et:
2012-05-21 04:12:37 -07:00
/* 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/. */
#include "leaky.h"
#ifdef USE_BFD
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <libgen.h>
#include <bfd.h>
extern "C" {
char *cplus_demangle (const char *mangled, int options);
}
static bfd *try_debug_file(const char *filename, unsigned long crc32)
{
int fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
unsigned char buf[4*1024];
unsigned long crc = 0;
while (1) {
ssize_t count = read(fd, buf, sizeof(buf));
if (count <= 0)
break;
crc = bfd_calc_gnu_debuglink_crc32(crc, buf, count);
}
close(fd);
if (crc != crc32)
return NULL;
bfd *object = bfd_openr(filename, NULL);
if (!bfd_check_format(object, bfd_object)) {
bfd_close(object);
return NULL;
}
return object;
}
static bfd *find_debug_file(bfd *lib, const char *aFileName)
{
// check for a separate debug file with symbols
asection *sect = bfd_get_section_by_name(lib, ".gnu_debuglink");
if (!sect)
return NULL;
bfd_size_type debuglinkSize = bfd_section_size (objfile->obfd, sect);
char *debuglink = new char[debuglinkSize];
bfd_get_section_contents(lib, sect, debuglink, 0, debuglinkSize);
// crc checksum is aligned to 4 bytes, and after the NUL.
int crc_offset = (int(strlen(debuglink)) & ~3) + 4;
unsigned long crc32 = bfd_get_32(lib, debuglink + crc_offset);
// directory component
char *dirbuf = strdup(aFileName);
const char *dir = dirname(dirbuf);
static const char debug_subdir[] = ".debug";
// This is gdb's default global debugging info directory, but gdb can
// be instructed to use a different directory.
static const char global_debug_dir[] = "/usr/lib/debug";
char *filename =
new char[strlen(global_debug_dir) + strlen(dir) + crc_offset + 3];
// /path/debuglink
sprintf(filename, "%s/%s", dir, debuglink);
bfd *debugFile = try_debug_file(filename, crc32);
if (!debugFile) {
// /path/.debug/debuglink
sprintf(filename, "%s/%s/%s", dir, debug_subdir, debuglink);
debugFile = try_debug_file(filename, crc32);
if (!debugFile) {
// /usr/lib/debug/path/debuglink
sprintf(filename, "%s/%s/%s", global_debug_dir, dir, debuglink);
debugFile = try_debug_file(filename, crc32);
}
}
delete[] filename;
free(dirbuf);
delete[] debuglink;
return debugFile;
}
#define NEXT_SYMBOL \
sp++; \
if (sp >= lastSymbol) { \
long n = numExternalSymbols + 10000; \
externalSymbols = (Symbol*) \
realloc(externalSymbols, (size_t) (sizeof(Symbol) * n)); \
lastSymbol = externalSymbols + n; \
sp = externalSymbols + numExternalSymbols; \
numExternalSymbols = n; \
}
void leaky::ReadSymbols(const char *aFileName, u_long aBaseAddress)
{
int initialSymbols = usefulSymbols;
if (NULL == externalSymbols) {
externalSymbols = (Symbol*) malloc(sizeof(Symbol) * 10000);
numExternalSymbols = 10000;
}
Symbol* sp = externalSymbols + usefulSymbols;
Symbol* lastSymbol = externalSymbols + numExternalSymbols;
// Create a dummy symbol for the library so, if it doesn't have any
// symbols, we show it by library.
sp->Init(aFileName, aBaseAddress);
NEXT_SYMBOL
bfd_boolean kDynamic = (bfd_boolean) false;
static int firstTime = 1;
if (firstTime) {
firstTime = 0;
bfd_init ();
}
bfd* lib = bfd_openr(aFileName, NULL);
if (NULL == lib) {
return;
}
if (!bfd_check_format(lib, bfd_object)) {
bfd_close(lib);
return;
}
bfd *symbolFile = find_debug_file(lib, aFileName);
// read mini symbols
PTR minisyms;
unsigned int size;
long symcount = 0;
if (symbolFile) {
symcount = bfd_read_minisymbols(symbolFile, kDynamic, &minisyms, &size);
if (symcount == 0) {
bfd_close(symbolFile);
} else {
bfd_close(lib);
}
}
if (symcount == 0) {
symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size);
if (symcount == 0) {
// symtab is empty; try dynamic symbols
kDynamic = (bfd_boolean) true;
symcount = bfd_read_minisymbols(lib, kDynamic, &minisyms, &size);
}
symbolFile = lib;
}
asymbol* store;
store = bfd_make_empty_symbol(symbolFile);
// Scan symbols
bfd_byte* from = (bfd_byte *) minisyms;
bfd_byte* fromend = from + symcount * size;
for (; from < fromend; from += size) {
asymbol *sym;
sym = bfd_minisymbol_to_symbol(symbolFile, kDynamic, (const PTR) from, store);
symbol_info syminfo;
bfd_get_symbol_info (symbolFile, sym, &syminfo);
// if ((syminfo.type == 'T') || (syminfo.type == 't')) {
const char* nm = bfd_asymbol_name(sym);
if (nm && nm[0]) {
char* dnm = NULL;
if (strncmp("__thunk", nm, 7)) {
dnm = cplus_demangle(nm, 1);
}
sp->Init(dnm ? dnm : nm, syminfo.value + aBaseAddress);
NEXT_SYMBOL
}
// }
}
bfd_close(symbolFile);
int interesting = sp - externalSymbols;
if (!quiet) {
printf("%s provided %d symbols\n", aFileName,
interesting - initialSymbols);
}
usefulSymbols = interesting;
}
#endif /* USE_BFD */