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![Jeff King](/assets/img/avatar_default.png)
We currently read the input to test-delta by mmap()-ing it. However, memory-checking tools like valgrind and ASan are less able to detect reads/writes past the end of an mmap'd buffer, because the OS is likely to give us extra bytes to pad out the final page size. So instead, let's read into a heap buffer. As a bonus, this also makes it possible to write tests with empty bases, as mmap() will complain about a zero-length map. This is based on a patch by Jann Horn <jannh@google.com> which actually aligned the data at the end of a page, and followed it with another page marked with mprotect(). That would detect problems even without a tool like ASan, but it was significantly more complex and may have introduced portability problems. By comparison, this approach pushes the complexity onto existing memory-checking tools. Note that this could be done even more simply by using strbuf_read_file(), but that would defeat the purpose: strbufs generally overallocate (and at the very least include a trailing NUL which we do not care about), which would defeat most memory checkers. Signed-off-by: Jeff King <peff@peff.net> Reviewed-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
/*
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* test-delta.c: test code to exercise diff-delta.c and patch-delta.c
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*
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* (C) 2005 Nicolas Pitre <nico@fluxnic.net>
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*
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* This code is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include "test-tool.h"
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#include "git-compat-util.h"
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#include "delta.h"
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#include "cache.h"
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static const char usage_str[] =
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"test-tool delta (-d|-p) <from_file> <data_file> <out_file>";
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int cmd__delta(int argc, const char **argv)
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{
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int fd;
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struct stat st;
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void *from_buf, *data_buf, *out_buf;
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unsigned long from_size, data_size, out_size;
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if (argc != 5 || (strcmp(argv[1], "-d") && strcmp(argv[1], "-p"))) {
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fprintf(stderr, "usage: %s\n", usage_str);
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return 1;
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}
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fd = open(argv[2], O_RDONLY);
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if (fd < 0 || fstat(fd, &st)) {
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perror(argv[2]);
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return 1;
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}
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from_size = st.st_size;
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from_buf = xmalloc(from_size);
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if (read_in_full(fd, from_buf, from_size) < 0) {
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perror(argv[2]);
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close(fd);
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return 1;
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}
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close(fd);
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fd = open(argv[3], O_RDONLY);
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if (fd < 0 || fstat(fd, &st)) {
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perror(argv[3]);
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return 1;
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}
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data_size = st.st_size;
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data_buf = xmalloc(data_size);
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if (read_in_full(fd, data_buf, data_size) < 0) {
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perror(argv[3]);
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close(fd);
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return 1;
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}
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close(fd);
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if (argv[1][1] == 'd')
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out_buf = diff_delta(from_buf, from_size,
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data_buf, data_size,
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&out_size, 0);
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else
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out_buf = patch_delta(from_buf, from_size,
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data_buf, data_size,
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&out_size);
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if (!out_buf) {
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fprintf(stderr, "delta operation failed (returned NULL)\n");
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return 1;
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}
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fd = open (argv[4], O_WRONLY|O_CREAT|O_TRUNC, 0666);
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if (fd < 0 || write_in_full(fd, out_buf, out_size) < 0) {
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perror(argv[4]);
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return 1;
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}
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return 0;
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}
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