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git/convert.c
Jeff King 5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00

1345 lines
30 KiB
C

#include "cache.h"
#include "attr.h"
#include "run-command.h"
#include "quote.h"
#include "sigchain.h"
/*
* convert.c - convert a file when checking it out and checking it in.
*
* This should use the pathname to decide on whether it wants to do some
* more interesting conversions (automatic gzip/unzip, general format
* conversions etc etc), but by default it just does automatic CRLF<->LF
* translation when the "text" attribute or "auto_crlf" option is set.
*/
enum crlf_action {
CRLF_GUESS = -1,
CRLF_BINARY = 0,
CRLF_TEXT,
CRLF_INPUT,
CRLF_CRLF,
CRLF_AUTO
};
struct text_stat {
/* NUL, CR, LF and CRLF counts */
unsigned nul, cr, lf, crlf;
/* These are just approximations! */
unsigned printable, nonprintable;
};
static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
{
unsigned long i;
memset(stats, 0, sizeof(*stats));
for (i = 0; i < size; i++) {
unsigned char c = buf[i];
if (c == '\r') {
stats->cr++;
if (i+1 < size && buf[i+1] == '\n')
stats->crlf++;
continue;
}
if (c == '\n') {
stats->lf++;
continue;
}
if (c == 127)
/* DEL */
stats->nonprintable++;
else if (c < 32) {
switch (c) {
/* BS, HT, ESC and FF */
case '\b': case '\t': case '\033': case '\014':
stats->printable++;
break;
case 0:
stats->nul++;
/* fall through */
default:
stats->nonprintable++;
}
}
else
stats->printable++;
}
/* If file ends with EOF then don't count this EOF as non-printable. */
if (size >= 1 && buf[size-1] == '\032')
stats->nonprintable--;
}
/*
* The same heuristics as diff.c::mmfile_is_binary()
*/
static int is_binary(unsigned long size, struct text_stat *stats)
{
if (stats->nul)
return 1;
if ((stats->printable >> 7) < stats->nonprintable)
return 1;
/*
* Other heuristics? Average line length might be relevant,
* as might LF vs CR vs CRLF counts..
*
* NOTE! It might be normal to have a low ratio of CRLF to LF
* (somebody starts with a LF-only file and edits it with an editor
* that adds CRLF only to lines that are added..). But do we
* want to support CR-only? Probably not.
*/
return 0;
}
static enum eol output_eol(enum crlf_action crlf_action)
{
switch (crlf_action) {
case CRLF_BINARY:
return EOL_UNSET;
case CRLF_CRLF:
return EOL_CRLF;
case CRLF_INPUT:
return EOL_LF;
case CRLF_GUESS:
if (!auto_crlf)
return EOL_UNSET;
/* fall through */
case CRLF_TEXT:
case CRLF_AUTO:
if (auto_crlf == AUTO_CRLF_TRUE)
return EOL_CRLF;
else if (auto_crlf == AUTO_CRLF_INPUT)
return EOL_LF;
else if (core_eol == EOL_UNSET)
return EOL_NATIVE;
}
return core_eol;
}
static void check_safe_crlf(const char *path, enum crlf_action crlf_action,
struct text_stat *stats, enum safe_crlf checksafe)
{
if (!checksafe)
return;
if (output_eol(crlf_action) == EOL_LF) {
/*
* CRLFs would not be restored by checkout:
* check if we'd remove CRLFs
*/
if (stats->crlf) {
if (checksafe == SAFE_CRLF_WARN)
warning("CRLF will be replaced by LF in %s.\nThe file will have its original line endings in your working directory.", path);
else /* i.e. SAFE_CRLF_FAIL */
die("CRLF would be replaced by LF in %s.", path);
}
} else if (output_eol(crlf_action) == EOL_CRLF) {
/*
* CRLFs would be added by checkout:
* check if we have "naked" LFs
*/
if (stats->lf != stats->crlf) {
if (checksafe == SAFE_CRLF_WARN)
warning("LF will be replaced by CRLF in %s.\nThe file will have its original line endings in your working directory.", path);
else /* i.e. SAFE_CRLF_FAIL */
die("LF would be replaced by CRLF in %s", path);
}
}
}
static int has_cr_in_index(const char *path)
{
unsigned long sz;
void *data;
int has_cr;
data = read_blob_data_from_cache(path, &sz);
if (!data)
return 0;
has_cr = memchr(data, '\r', sz) != NULL;
free(data);
return has_cr;
}
static int crlf_to_git(const char *path, const char *src, size_t len,
struct strbuf *buf,
enum crlf_action crlf_action, enum safe_crlf checksafe)
{
struct text_stat stats;
char *dst;
if (crlf_action == CRLF_BINARY ||
(crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE) ||
(src && !len))
return 0;
/*
* If we are doing a dry-run and have no source buffer, there is
* nothing to analyze; we must assume we would convert.
*/
if (!buf && !src)
return 1;
gather_stats(src, len, &stats);
if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
/*
* We're currently not going to even try to convert stuff
* that has bare CR characters. Does anybody do that crazy
* stuff?
*/
if (stats.cr != stats.crlf)
return 0;
/*
* And add some heuristics for binary vs text, of course...
*/
if (is_binary(len, &stats))
return 0;
if (crlf_action == CRLF_GUESS) {
/*
* If the file in the index has any CR in it, do not convert.
* This is the new safer autocrlf handling.
*/
if (has_cr_in_index(path))
return 0;
}
}
check_safe_crlf(path, crlf_action, &stats, checksafe);
/* Optimization: No CR? Nothing to convert, regardless. */
if (!stats.cr)
return 0;
/*
* At this point all of our source analysis is done, and we are sure we
* would convert. If we are in dry-run mode, we can give an answer.
*/
if (!buf)
return 1;
/* only grow if not in place */
if (strbuf_avail(buf) + buf->len < len)
strbuf_grow(buf, len - buf->len);
dst = buf->buf;
if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
/*
* If we guessed, we already know we rejected a file with
* lone CR, and we can strip a CR without looking at what
* follow it.
*/
do {
unsigned char c = *src++;
if (c != '\r')
*dst++ = c;
} while (--len);
} else {
do {
unsigned char c = *src++;
if (! (c == '\r' && (1 < len && *src == '\n')))
*dst++ = c;
} while (--len);
}
strbuf_setlen(buf, dst - buf->buf);
return 1;
}
static int crlf_to_worktree(const char *path, const char *src, size_t len,
struct strbuf *buf, enum crlf_action crlf_action)
{
char *to_free = NULL;
struct text_stat stats;
if (!len || output_eol(crlf_action) != EOL_CRLF)
return 0;
gather_stats(src, len, &stats);
/* No LF? Nothing to convert, regardless. */
if (!stats.lf)
return 0;
/* Was it already in CRLF format? */
if (stats.lf == stats.crlf)
return 0;
if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
if (crlf_action == CRLF_GUESS) {
/* If we have any CR or CRLF line endings, we do not touch it */
/* This is the new safer autocrlf-handling */
if (stats.cr > 0 || stats.crlf > 0)
return 0;
}
/* If we have any bare CR characters, we're not going to touch it */
if (stats.cr != stats.crlf)
return 0;
if (is_binary(len, &stats))
return 0;
}
/* are we "faking" in place editing ? */
if (src == buf->buf)
to_free = strbuf_detach(buf, NULL);
strbuf_grow(buf, len + stats.lf - stats.crlf);
for (;;) {
const char *nl = memchr(src, '\n', len);
if (!nl)
break;
if (nl > src && nl[-1] == '\r') {
strbuf_add(buf, src, nl + 1 - src);
} else {
strbuf_add(buf, src, nl - src);
strbuf_addstr(buf, "\r\n");
}
len -= nl + 1 - src;
src = nl + 1;
}
strbuf_add(buf, src, len);
free(to_free);
return 1;
}
struct filter_params {
const char *src;
unsigned long size;
int fd;
const char *cmd;
const char *path;
};
static int filter_buffer_or_fd(int in, int out, void *data)
{
/*
* Spawn cmd and feed the buffer contents through its stdin.
*/
struct child_process child_process = CHILD_PROCESS_INIT;
struct filter_params *params = (struct filter_params *)data;
int write_err, status;
const char *argv[] = { NULL, NULL };
/* apply % substitution to cmd */
struct strbuf cmd = STRBUF_INIT;
struct strbuf path = STRBUF_INIT;
struct strbuf_expand_dict_entry dict[] = {
{ "f", NULL, },
{ NULL, NULL, },
};
/* quote the path to preserve spaces, etc. */
sq_quote_buf(&path, params->path);
dict[0].value = path.buf;
/* expand all %f with the quoted path */
strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
strbuf_release(&path);
argv[0] = cmd.buf;
child_process.argv = argv;
child_process.use_shell = 1;
child_process.in = -1;
child_process.out = out;
if (start_command(&child_process))
return error("cannot fork to run external filter %s", params->cmd);
sigchain_push(SIGPIPE, SIG_IGN);
if (params->src) {
write_err = (write_in_full(child_process.in,
params->src, params->size) < 0);
if (errno == EPIPE)
write_err = 0;
} else {
write_err = copy_fd(params->fd, child_process.in);
if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
write_err = 0;
}
if (close(child_process.in))
write_err = 1;
if (write_err)
error("cannot feed the input to external filter %s", params->cmd);
sigchain_pop(SIGPIPE);
status = finish_command(&child_process);
if (status)
error("external filter %s failed %d", params->cmd, status);
strbuf_release(&cmd);
return (write_err || status);
}
static int apply_filter(const char *path, const char *src, size_t len, int fd,
struct strbuf *dst, const char *cmd)
{
/*
* Create a pipeline to have the command filter the buffer's
* contents.
*
* (child --> cmd) --> us
*/
int ret = 1;
struct strbuf nbuf = STRBUF_INIT;
struct async async;
struct filter_params params;
if (!cmd)
return 0;
if (!dst)
return 1;
memset(&async, 0, sizeof(async));
async.proc = filter_buffer_or_fd;
async.data = &params;
async.out = -1;
params.src = src;
params.size = len;
params.fd = fd;
params.cmd = cmd;
params.path = path;
fflush(NULL);
if (start_async(&async))
return 0; /* error was already reported */
if (strbuf_read(&nbuf, async.out, len) < 0) {
error("read from external filter %s failed", cmd);
ret = 0;
}
if (close(async.out)) {
error("read from external filter %s failed", cmd);
ret = 0;
}
if (finish_async(&async)) {
error("external filter %s failed", cmd);
ret = 0;
}
if (ret) {
strbuf_swap(dst, &nbuf);
}
strbuf_release(&nbuf);
return ret;
}
static struct convert_driver {
const char *name;
struct convert_driver *next;
const char *smudge;
const char *clean;
int required;
} *user_convert, **user_convert_tail;
static int read_convert_config(const char *var, const char *value, void *cb)
{
const char *key, *name;
int namelen;
struct convert_driver *drv;
/*
* External conversion drivers are configured using
* "filter.<name>.variable".
*/
if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
return 0;
for (drv = user_convert; drv; drv = drv->next)
if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
break;
if (!drv) {
drv = xcalloc(1, sizeof(struct convert_driver));
drv->name = xmemdupz(name, namelen);
*user_convert_tail = drv;
user_convert_tail = &(drv->next);
}
/*
* filter.<name>.smudge and filter.<name>.clean specifies
* the command line:
*
* command-line
*
* The command-line will not be interpolated in any way.
*/
if (!strcmp("smudge", key))
return git_config_string(&drv->smudge, var, value);
if (!strcmp("clean", key))
return git_config_string(&drv->clean, var, value);
if (!strcmp("required", key)) {
drv->required = git_config_bool(var, value);
return 0;
}
return 0;
}
static int count_ident(const char *cp, unsigned long size)
{
/*
* "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
*/
int cnt = 0;
char ch;
while (size) {
ch = *cp++;
size--;
if (ch != '$')
continue;
if (size < 3)
break;
if (memcmp("Id", cp, 2))
continue;
ch = cp[2];
cp += 3;
size -= 3;
if (ch == '$')
cnt++; /* $Id$ */
if (ch != ':')
continue;
/*
* "$Id: ... "; scan up to the closing dollar sign and discard.
*/
while (size) {
ch = *cp++;
size--;
if (ch == '$') {
cnt++;
break;
}
if (ch == '\n')
break;
}
}
return cnt;
}
static int ident_to_git(const char *path, const char *src, size_t len,
struct strbuf *buf, int ident)
{
char *dst, *dollar;
if (!ident || (src && !count_ident(src, len)))
return 0;
if (!buf)
return 1;
/* only grow if not in place */
if (strbuf_avail(buf) + buf->len < len)
strbuf_grow(buf, len - buf->len);
dst = buf->buf;
for (;;) {
dollar = memchr(src, '$', len);
if (!dollar)
break;
memmove(dst, src, dollar + 1 - src);
dst += dollar + 1 - src;
len -= dollar + 1 - src;
src = dollar + 1;
if (len > 3 && !memcmp(src, "Id:", 3)) {
dollar = memchr(src + 3, '$', len - 3);
if (!dollar)
break;
if (memchr(src + 3, '\n', dollar - src - 3)) {
/* Line break before the next dollar. */
continue;
}
memcpy(dst, "Id$", 3);
dst += 3;
len -= dollar + 1 - src;
src = dollar + 1;
}
}
memmove(dst, src, len);
strbuf_setlen(buf, dst + len - buf->buf);
return 1;
}
static int ident_to_worktree(const char *path, const char *src, size_t len,
struct strbuf *buf, int ident)
{
unsigned char sha1[20];
char *to_free = NULL, *dollar, *spc;
int cnt;
if (!ident)
return 0;
cnt = count_ident(src, len);
if (!cnt)
return 0;
/* are we "faking" in place editing ? */
if (src == buf->buf)
to_free = strbuf_detach(buf, NULL);
hash_sha1_file(src, len, "blob", sha1);
strbuf_grow(buf, len + cnt * 43);
for (;;) {
/* step 1: run to the next '$' */
dollar = memchr(src, '$', len);
if (!dollar)
break;
strbuf_add(buf, src, dollar + 1 - src);
len -= dollar + 1 - src;
src = dollar + 1;
/* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
if (len < 3 || memcmp("Id", src, 2))
continue;
/* step 3: skip over Id$ or Id:xxxxx$ */
if (src[2] == '$') {
src += 3;
len -= 3;
} else if (src[2] == ':') {
/*
* It's possible that an expanded Id has crept its way into the
* repository, we cope with that by stripping the expansion out.
* This is probably not a good idea, since it will cause changes
* on checkout, which won't go away by stash, but let's keep it
* for git-style ids.
*/
dollar = memchr(src + 3, '$', len - 3);
if (!dollar) {
/* incomplete keyword, no more '$', so just quit the loop */
break;
}
if (memchr(src + 3, '\n', dollar - src - 3)) {
/* Line break before the next dollar. */
continue;
}
spc = memchr(src + 4, ' ', dollar - src - 4);
if (spc && spc < dollar-1) {
/* There are spaces in unexpected places.
* This is probably an id from some other
* versioning system. Keep it for now.
*/
continue;
}
len -= dollar + 1 - src;
src = dollar + 1;
} else {
/* it wasn't a "Id$" or "Id:xxxx$" */
continue;
}
/* step 4: substitute */
strbuf_addstr(buf, "Id: ");
strbuf_add(buf, sha1_to_hex(sha1), 40);
strbuf_addstr(buf, " $");
}
strbuf_add(buf, src, len);
free(to_free);
return 1;
}
static enum crlf_action git_path_check_crlf(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
if (ATTR_TRUE(value))
return CRLF_TEXT;
else if (ATTR_FALSE(value))
return CRLF_BINARY;
else if (ATTR_UNSET(value))
;
else if (!strcmp(value, "input"))
return CRLF_INPUT;
else if (!strcmp(value, "auto"))
return CRLF_AUTO;
return CRLF_GUESS;
}
static enum eol git_path_check_eol(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
if (ATTR_UNSET(value))
;
else if (!strcmp(value, "lf"))
return EOL_LF;
else if (!strcmp(value, "crlf"))
return EOL_CRLF;
return EOL_UNSET;
}
static struct convert_driver *git_path_check_convert(const char *path,
struct git_attr_check *check)
{
const char *value = check->value;
struct convert_driver *drv;
if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
return NULL;
for (drv = user_convert; drv; drv = drv->next)
if (!strcmp(value, drv->name))
return drv;
return NULL;
}
static int git_path_check_ident(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
return !!ATTR_TRUE(value);
}
static enum crlf_action input_crlf_action(enum crlf_action text_attr, enum eol eol_attr)
{
if (text_attr == CRLF_BINARY)
return CRLF_BINARY;
if (eol_attr == EOL_LF)
return CRLF_INPUT;
if (eol_attr == EOL_CRLF)
return CRLF_CRLF;
return text_attr;
}
struct conv_attrs {
struct convert_driver *drv;
enum crlf_action crlf_action;
enum eol eol_attr;
int ident;
};
static const char *conv_attr_name[] = {
"crlf", "ident", "filter", "eol", "text",
};
#define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
static void convert_attrs(struct conv_attrs *ca, const char *path)
{
int i;
static struct git_attr_check ccheck[NUM_CONV_ATTRS];
if (!ccheck[0].attr) {
for (i = 0; i < NUM_CONV_ATTRS; i++)
ccheck[i].attr = git_attr(conv_attr_name[i]);
user_convert_tail = &user_convert;
git_config(read_convert_config, NULL);
}
if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
ca->crlf_action = git_path_check_crlf(path, ccheck + 4);
if (ca->crlf_action == CRLF_GUESS)
ca->crlf_action = git_path_check_crlf(path, ccheck + 0);
ca->ident = git_path_check_ident(path, ccheck + 1);
ca->drv = git_path_check_convert(path, ccheck + 2);
ca->eol_attr = git_path_check_eol(path, ccheck + 3);
} else {
ca->drv = NULL;
ca->crlf_action = CRLF_GUESS;
ca->eol_attr = EOL_UNSET;
ca->ident = 0;
}
}
int would_convert_to_git_filter_fd(const char *path)
{
struct conv_attrs ca;
convert_attrs(&ca, path);
if (!ca.drv)
return 0;
/*
* Apply a filter to an fd only if the filter is required to succeed.
* We must die if the filter fails, because the original data before
* filtering is not available.
*/
if (!ca.drv->required)
return 0;
return apply_filter(path, NULL, 0, -1, NULL, ca.drv->clean);
}
int convert_to_git(const char *path, const char *src, size_t len,
struct strbuf *dst, enum safe_crlf checksafe)
{
int ret = 0;
const char *filter = NULL;
int required = 0;
struct conv_attrs ca;
convert_attrs(&ca, path);
if (ca.drv) {
filter = ca.drv->clean;
required = ca.drv->required;
}
ret |= apply_filter(path, src, len, -1, dst, filter);
if (!ret && required)
die("%s: clean filter '%s' failed", path, ca.drv->name);
if (ret && dst) {
src = dst->buf;
len = dst->len;
}
ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
ret |= crlf_to_git(path, src, len, dst, ca.crlf_action, checksafe);
if (ret && dst) {
src = dst->buf;
len = dst->len;
}
return ret | ident_to_git(path, src, len, dst, ca.ident);
}
void convert_to_git_filter_fd(const char *path, int fd, struct strbuf *dst,
enum safe_crlf checksafe)
{
struct conv_attrs ca;
convert_attrs(&ca, path);
assert(ca.drv);
assert(ca.drv->clean);
if (!apply_filter(path, NULL, 0, fd, dst, ca.drv->clean))
die("%s: clean filter '%s' failed", path, ca.drv->name);
ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
crlf_to_git(path, dst->buf, dst->len, dst, ca.crlf_action, checksafe);
ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
}
static int convert_to_working_tree_internal(const char *path, const char *src,
size_t len, struct strbuf *dst,
int normalizing)
{
int ret = 0, ret_filter = 0;
const char *filter = NULL;
int required = 0;
struct conv_attrs ca;
convert_attrs(&ca, path);
if (ca.drv) {
filter = ca.drv->smudge;
required = ca.drv->required;
}
ret |= ident_to_worktree(path, src, len, dst, ca.ident);
if (ret) {
src = dst->buf;
len = dst->len;
}
/*
* CRLF conversion can be skipped if normalizing, unless there
* is a smudge filter. The filter might expect CRLFs.
*/
if (filter || !normalizing) {
ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
if (ret) {
src = dst->buf;
len = dst->len;
}
}
ret_filter = apply_filter(path, src, len, -1, dst, filter);
if (!ret_filter && required)
die("%s: smudge filter %s failed", path, ca.drv->name);
return ret | ret_filter;
}
int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
{
return convert_to_working_tree_internal(path, src, len, dst, 0);
}
int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst)
{
int ret = convert_to_working_tree_internal(path, src, len, dst, 1);
if (ret) {
src = dst->buf;
len = dst->len;
}
return ret | convert_to_git(path, src, len, dst, SAFE_CRLF_FALSE);
}
/*****************************************************************
*
* Streaming conversion support
*
*****************************************************************/
typedef int (*filter_fn)(struct stream_filter *,
const char *input, size_t *isize_p,
char *output, size_t *osize_p);
typedef void (*free_fn)(struct stream_filter *);
struct stream_filter_vtbl {
filter_fn filter;
free_fn free;
};
struct stream_filter {
struct stream_filter_vtbl *vtbl;
};
static int null_filter_fn(struct stream_filter *filter,
const char *input, size_t *isize_p,
char *output, size_t *osize_p)
{
size_t count;
if (!input)
return 0; /* we do not keep any states */
count = *isize_p;
if (*osize_p < count)
count = *osize_p;
if (count) {
memmove(output, input, count);
*isize_p -= count;
*osize_p -= count;
}
return 0;
}
static void null_free_fn(struct stream_filter *filter)
{
; /* nothing -- null instances are shared */
}
static struct stream_filter_vtbl null_vtbl = {
null_filter_fn,
null_free_fn,
};
static struct stream_filter null_filter_singleton = {
&null_vtbl,
};
int is_null_stream_filter(struct stream_filter *filter)
{
return filter == &null_filter_singleton;
}
/*
* LF-to-CRLF filter
*/
struct lf_to_crlf_filter {
struct stream_filter filter;
unsigned has_held:1;
char held;
};
static int lf_to_crlf_filter_fn(struct stream_filter *filter,
const char *input, size_t *isize_p,
char *output, size_t *osize_p)
{
size_t count, o = 0;
struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
/*
* We may be holding onto the CR to see if it is followed by a
* LF, in which case we would need to go to the main loop.
* Otherwise, just emit it to the output stream.
*/
if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
output[o++] = lf_to_crlf->held;
lf_to_crlf->has_held = 0;
}
/* We are told to drain */
if (!input) {
*osize_p -= o;
return 0;
}
count = *isize_p;
if (count || lf_to_crlf->has_held) {
size_t i;
int was_cr = 0;
if (lf_to_crlf->has_held) {
was_cr = 1;
lf_to_crlf->has_held = 0;
}
for (i = 0; o < *osize_p && i < count; i++) {
char ch = input[i];
if (ch == '\n') {
output[o++] = '\r';
} else if (was_cr) {
/*
* Previous round saw CR and it is not followed
* by a LF; emit the CR before processing the
* current character.
*/
output[o++] = '\r';
}
/*
* We may have consumed the last output slot,
* in which case we need to break out of this
* loop; hold the current character before
* returning.
*/
if (*osize_p <= o) {
lf_to_crlf->has_held = 1;
lf_to_crlf->held = ch;
continue; /* break but increment i */
}
if (ch == '\r') {
was_cr = 1;
continue;
}
was_cr = 0;
output[o++] = ch;
}
*osize_p -= o;
*isize_p -= i;
if (!lf_to_crlf->has_held && was_cr) {
lf_to_crlf->has_held = 1;
lf_to_crlf->held = '\r';
}
}
return 0;
}
static void lf_to_crlf_free_fn(struct stream_filter *filter)
{
free(filter);
}
static struct stream_filter_vtbl lf_to_crlf_vtbl = {
lf_to_crlf_filter_fn,
lf_to_crlf_free_fn,
};
static struct stream_filter *lf_to_crlf_filter(void)
{
struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
return (struct stream_filter *)lf_to_crlf;
}
/*
* Cascade filter
*/
#define FILTER_BUFFER 1024
struct cascade_filter {
struct stream_filter filter;
struct stream_filter *one;
struct stream_filter *two;
char buf[FILTER_BUFFER];
int end, ptr;
};
static int cascade_filter_fn(struct stream_filter *filter,
const char *input, size_t *isize_p,
char *output, size_t *osize_p)
{
struct cascade_filter *cas = (struct cascade_filter *) filter;
size_t filled = 0;
size_t sz = *osize_p;
size_t to_feed, remaining;
/*
* input -- (one) --> buf -- (two) --> output
*/
while (filled < sz) {
remaining = sz - filled;
/* do we already have something to feed two with? */
if (cas->ptr < cas->end) {
to_feed = cas->end - cas->ptr;
if (stream_filter(cas->two,
cas->buf + cas->ptr, &to_feed,
output + filled, &remaining))
return -1;
cas->ptr += (cas->end - cas->ptr) - to_feed;
filled = sz - remaining;
continue;
}
/* feed one from upstream and have it emit into our buffer */
to_feed = input ? *isize_p : 0;
if (input && !to_feed)
break;
remaining = sizeof(cas->buf);
if (stream_filter(cas->one,
input, &to_feed,
cas->buf, &remaining))
return -1;
cas->end = sizeof(cas->buf) - remaining;
cas->ptr = 0;
if (input) {
size_t fed = *isize_p - to_feed;
*isize_p -= fed;
input += fed;
}
/* do we know that we drained one completely? */
if (input || cas->end)
continue;
/* tell two to drain; we have nothing more to give it */
to_feed = 0;
remaining = sz - filled;
if (stream_filter(cas->two,
NULL, &to_feed,
output + filled, &remaining))
return -1;
if (remaining == (sz - filled))
break; /* completely drained two */
filled = sz - remaining;
}
*osize_p -= filled;
return 0;
}
static void cascade_free_fn(struct stream_filter *filter)
{
struct cascade_filter *cas = (struct cascade_filter *)filter;
free_stream_filter(cas->one);
free_stream_filter(cas->two);
free(filter);
}
static struct stream_filter_vtbl cascade_vtbl = {
cascade_filter_fn,
cascade_free_fn,
};
static struct stream_filter *cascade_filter(struct stream_filter *one,
struct stream_filter *two)
{
struct cascade_filter *cascade;
if (!one || is_null_stream_filter(one))
return two;
if (!two || is_null_stream_filter(two))
return one;
cascade = xmalloc(sizeof(*cascade));
cascade->one = one;
cascade->two = two;
cascade->end = cascade->ptr = 0;
cascade->filter.vtbl = &cascade_vtbl;
return (struct stream_filter *)cascade;
}
/*
* ident filter
*/
#define IDENT_DRAINING (-1)
#define IDENT_SKIPPING (-2)
struct ident_filter {
struct stream_filter filter;
struct strbuf left;
int state;
char ident[45]; /* ": x40 $" */
};
static int is_foreign_ident(const char *str)
{
int i;
if (!skip_prefix(str, "$Id: ", &str))
return 0;
for (i = 0; str[i]; i++) {
if (isspace(str[i]) && str[i+1] != '$')
return 1;
}
return 0;
}
static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
{
size_t to_drain = ident->left.len;
if (*osize_p < to_drain)
to_drain = *osize_p;
if (to_drain) {
memcpy(*output_p, ident->left.buf, to_drain);
strbuf_remove(&ident->left, 0, to_drain);
*output_p += to_drain;
*osize_p -= to_drain;
}
if (!ident->left.len)
ident->state = 0;
}
static int ident_filter_fn(struct stream_filter *filter,
const char *input, size_t *isize_p,
char *output, size_t *osize_p)
{
struct ident_filter *ident = (struct ident_filter *)filter;
static const char head[] = "$Id";
if (!input) {
/* drain upon eof */
switch (ident->state) {
default:
strbuf_add(&ident->left, head, ident->state);
case IDENT_SKIPPING:
/* fallthru */
case IDENT_DRAINING:
ident_drain(ident, &output, osize_p);
}
return 0;
}
while (*isize_p || (ident->state == IDENT_DRAINING)) {
int ch;
if (ident->state == IDENT_DRAINING) {
ident_drain(ident, &output, osize_p);
if (!*osize_p)
break;
continue;
}
ch = *(input++);
(*isize_p)--;
if (ident->state == IDENT_SKIPPING) {
/*
* Skipping until '$' or LF, but keeping them
* in case it is a foreign ident.
*/
strbuf_addch(&ident->left, ch);
if (ch != '\n' && ch != '$')
continue;
if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
strbuf_setlen(&ident->left, sizeof(head) - 1);
strbuf_addstr(&ident->left, ident->ident);
}
ident->state = IDENT_DRAINING;
continue;
}
if (ident->state < sizeof(head) &&
head[ident->state] == ch) {
ident->state++;
continue;
}
if (ident->state)
strbuf_add(&ident->left, head, ident->state);
if (ident->state == sizeof(head) - 1) {
if (ch != ':' && ch != '$') {
strbuf_addch(&ident->left, ch);
ident->state = 0;
continue;
}
if (ch == ':') {
strbuf_addch(&ident->left, ch);
ident->state = IDENT_SKIPPING;
} else {
strbuf_addstr(&ident->left, ident->ident);
ident->state = IDENT_DRAINING;
}
continue;
}
strbuf_addch(&ident->left, ch);
ident->state = IDENT_DRAINING;
}
return 0;
}
static void ident_free_fn(struct stream_filter *filter)
{
struct ident_filter *ident = (struct ident_filter *)filter;
strbuf_release(&ident->left);
free(filter);
}
static struct stream_filter_vtbl ident_vtbl = {
ident_filter_fn,
ident_free_fn,
};
static struct stream_filter *ident_filter(const unsigned char *sha1)
{
struct ident_filter *ident = xmalloc(sizeof(*ident));
xsnprintf(ident->ident, sizeof(ident->ident),
": %s $", sha1_to_hex(sha1));
strbuf_init(&ident->left, 0);
ident->filter.vtbl = &ident_vtbl;
ident->state = 0;
return (struct stream_filter *)ident;
}
/*
* Return an appropriately constructed filter for the path, or NULL if
* the contents cannot be filtered without reading the whole thing
* in-core.
*
* Note that you would be crazy to set CRLF, smuge/clean or ident to a
* large binary blob you would want us not to slurp into the memory!
*/
struct stream_filter *get_stream_filter(const char *path, const unsigned char *sha1)
{
struct conv_attrs ca;
enum crlf_action crlf_action;
struct stream_filter *filter = NULL;
convert_attrs(&ca, path);
if (ca.drv && (ca.drv->smudge || ca.drv->clean))
return filter;
if (ca.ident)
filter = ident_filter(sha1);
crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
if ((crlf_action == CRLF_BINARY) || (crlf_action == CRLF_INPUT) ||
(crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE))
filter = cascade_filter(filter, &null_filter_singleton);
else if (output_eol(crlf_action) == EOL_CRLF &&
!(crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS))
filter = cascade_filter(filter, lf_to_crlf_filter());
return filter;
}
void free_stream_filter(struct stream_filter *filter)
{
filter->vtbl->free(filter);
}
int stream_filter(struct stream_filter *filter,
const char *input, size_t *isize_p,
char *output, size_t *osize_p)
{
return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
}