base: support gzip-compressed object files

This commit is contained in:
Curtis Dunham 2016-02-29 19:13:13 -06:00
parent 28289e5995
commit aa674268e9

View file

@ -33,6 +33,7 @@
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <zlib.h>
#include <cstdio>
#include <list>
@ -101,6 +102,61 @@ ObjectFile::close()
}
}
static bool
hasGzipMagic(int fd)
{
uint8_t buf[2] = {0};
size_t sz = pread(fd, buf, 2, 0);
panic_if(sz != 2, "Couldn't read magic bytes from object file");
return ((buf[0] == 0x1f) && (buf[1] == 0x8b));
}
static int
doGzipLoad(int fd)
{
const size_t blk_sz = 4096;
gzFile fdz = gzdopen(fd, "rb");
if (!fdz) {
return -1;
}
size_t tmp_len = strlen(P_tmpdir);
char *tmpnam = (char*) malloc(tmp_len + 20);
strcpy(tmpnam, P_tmpdir);
strcpy(tmpnam+tmp_len, "/gem5-gz-obj-XXXXXX"); // 19 chars
fd = mkstemp(tmpnam); // repurposing fd variable for output
if (fd < 0) {
free(tmpnam);
gzclose(fdz);
return fd;
}
if (unlink(tmpnam) != 0)
warn("couldn't remove temporary file %s\n", tmpnam);
free(tmpnam);
auto buf = new uint8_t[blk_sz];
int r; // size of (r)emaining uncopied data in (buf)fer
while ((r = gzread(fdz, buf, blk_sz)) > 0) {
auto p = buf; // pointer into buffer
while (r > 0) {
auto sz = write(fd, p, r);
assert(sz <= r);
r -= sz;
p += sz;
}
}
delete[] buf;
gzclose(fdz);
if (r < 0) { // error
close(fd);
return -1;
}
assert(r == 0); // finished successfully
return fd; // return fd to decompressed temporary file for mmap()'ing
}
ObjectFile *
createObjectFile(const string &fname, bool raw)
@ -111,15 +167,24 @@ createObjectFile(const string &fname, bool raw)
return NULL;
}
// decompress GZ files
if (hasGzipMagic(fd)) {
fd = doGzipLoad(fd);
if (fd < 0) {
return NULL;
}
}
// find the length of the file by seeking to the end
off_t off = lseek(fd, 0, SEEK_END);
fatal_if(off < 0, "Failed to determine size of object file %s\n", fname);
size_t len = static_cast<size_t>(off);
fatal_if(off < 0,
"Failed to determine size of object file %s\n", fname);
auto len = static_cast<size_t>(off);
// mmap the whole shebang
uint8_t *fileData =
(uint8_t *)mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
auto fileData = (uint8_t *)mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
close(fd);
if (fileData == MAP_FAILED) {
return NULL;
}