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git/convert.c
Johannes Sixt 5709e0363a run_command: return exit code as positive value
As a general guideline, functions in git's code return zero to indicate
success and negative values to indicate failure. The run_command family of
functions followed this guideline. But there are actually two different
kinds of failure:

- failures of system calls;

- non-zero exit code of the program that was run.

Usually, a non-zero exit code of the program is a failure and means a
failure to the caller. Except that sometimes it does not. For example, the
exit code of merge programs (e.g. external merge drivers) conveys
information about how the merge failed, and not all exit calls are
actually failures.

Furthermore, the return value of run_command is sometimes used as exit
code by the caller.

This change arranges that the exit code of the program is returned as a
positive value, which can now be regarded as the "result" of the function.
System call failures continue to be reported as negative values.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-05 12:16:27 -07:00

628 lines
14 KiB
C

#include "cache.h"
#include "attr.h"
#include "run-command.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 "auto_crlf" option is set.
*/
#define CRLF_GUESS (-1)
#define CRLF_BINARY 0
#define CRLF_TEXT 1
#define CRLF_INPUT 2
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 void check_safe_crlf(const char *path, int action,
struct text_stat *stats, enum safe_crlf checksafe)
{
if (!checksafe)
return;
if (action == CRLF_INPUT || auto_crlf <= 0) {
/*
* 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.", path);
else /* i.e. SAFE_CRLF_FAIL */
die("CRLF would be replaced by LF in %s.", path);
}
} else if (auto_crlf > 0) {
/*
* 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", path);
else /* i.e. SAFE_CRLF_FAIL */
die("LF would be replaced by CRLF in %s", path);
}
}
}
static int crlf_to_git(const char *path, const char *src, size_t len,
struct strbuf *buf, int action, enum safe_crlf checksafe)
{
struct text_stat stats;
char *dst;
if ((action == CRLF_BINARY) || !auto_crlf || !len)
return 0;
gather_stats(src, len, &stats);
if (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;
}
check_safe_crlf(path, action, &stats, checksafe);
/* Optimization: No CR? Nothing to convert, regardless. */
if (!stats.cr)
return 0;
/* only grow if not in place */
if (strbuf_avail(buf) + buf->len < len)
strbuf_grow(buf, len - buf->len);
dst = buf->buf;
if (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, int action)
{
char *to_free = NULL;
struct text_stat stats;
if ((action == CRLF_BINARY) || (action == CRLF_INPUT) ||
auto_crlf <= 0)
return 0;
if (!len)
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 (action == CRLF_GUESS) {
/* 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;
const char *cmd;
};
static int filter_buffer(int fd, void *data)
{
/*
* Spawn cmd and feed the buffer contents through its stdin.
*/
struct child_process child_process;
struct filter_params *params = (struct filter_params *)data;
int write_err, status;
const char *argv[] = { "sh", "-c", params->cmd, NULL };
memset(&child_process, 0, sizeof(child_process));
child_process.argv = argv;
child_process.in = -1;
child_process.out = fd;
if (start_command(&child_process))
return error("cannot fork to run external filter %s", params->cmd);
write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
if (close(child_process.in))
write_err = 1;
if (write_err)
error("cannot feed the input to external filter %s", params->cmd);
status = finish_command(&child_process);
if (status)
error("external filter %s failed %d", params->cmd, status);
return (write_err || status);
}
static int apply_filter(const char *path, const char *src, size_t len,
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;
memset(&async, 0, sizeof(async));
async.proc = filter_buffer;
async.data = &params;
params.src = src;
params.size = len;
params.cmd = cmd;
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;
} *user_convert, **user_convert_tail;
static int read_convert_config(const char *var, const char *value, void *cb)
{
const char *ep, *name;
int namelen;
struct convert_driver *drv;
/*
* External conversion drivers are configured using
* "filter.<name>.variable".
*/
if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6)
return 0;
name = var + 7;
namelen = ep - name;
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);
}
ep++;
/*
* 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", ep))
return git_config_string(&drv->smudge, var, value);
if (!strcmp("clean", ep))
return git_config_string(&drv->clean, var, value);
return 0;
}
static void setup_convert_check(struct git_attr_check *check)
{
static struct git_attr *attr_crlf;
static struct git_attr *attr_ident;
static struct git_attr *attr_filter;
if (!attr_crlf) {
attr_crlf = git_attr("crlf", 4);
attr_ident = git_attr("ident", 5);
attr_filter = git_attr("filter", 6);
user_convert_tail = &user_convert;
git_config(read_convert_config, NULL);
}
check[0].attr = attr_crlf;
check[1].attr = attr_ident;
check[2].attr = attr_filter;
}
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;
}
}
}
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 || !count_ident(src, len))
return 0;
/* 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, '$', len);
if (!dollar)
break;
memcpy(dst, src, dollar + 1 - src);
dst += dollar + 1 - src;
len -= dollar + 1 - src;
src = dollar + 1;
if (len > 3 && !memcmp(src, "Id:", 3)) {
dollar = memchr(src + 3, '$', len - 3);
if (!dollar)
break;
memcpy(dst, "Id$", 3);
dst += 3;
len -= dollar + 1 - src;
src = dollar + 1;
}
}
memcpy(dst, src, len);
strbuf_setlen(buf, dst + len - buf->buf);
return 1;
}
static int ident_to_worktree(const char *path, const char *src, size_t len,
struct strbuf *buf, int ident)
{
unsigned char sha1[20];
char *to_free = NULL, *dollar;
int cnt;
if (!ident)
return 0;
cnt = count_ident(src, len);
if (!cnt)
return 0;
/* are we "faking" in place editing ? */
if (src == buf->buf)
to_free = strbuf_detach(buf, NULL);
hash_sha1_file(src, len, "blob", sha1);
strbuf_grow(buf, len + cnt * 43);
for (;;) {
/* step 1: run to the next '$' */
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] == '$') {
src += 3;
len -= 3;
} else if (src[2] == ':') {
/*
* It's possible that an expanded Id has crept its way into the
* repository, we cope with that by stripping the expansion out
*/
dollar = memchr(src + 3, '$', len - 3);
if (!dollar) {
/* incomplete keyword, no more '$', so just quit the loop */
break;
}
len -= dollar + 1 - src;
src = dollar + 1;
} else {
/* it wasn't a "Id$" 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 int 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;
return CRLF_GUESS;
}
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);
}
int convert_to_git(const char *path, const char *src, size_t len,
struct strbuf *dst, enum safe_crlf checksafe)
{
struct git_attr_check check[3];
int crlf = CRLF_GUESS;
int ident = 0, ret = 0;
const char *filter = NULL;
setup_convert_check(check);
if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->clean)
filter = drv->clean;
}
ret |= apply_filter(path, src, len, dst, filter);
if (ret) {
src = dst->buf;
len = dst->len;
}
ret |= crlf_to_git(path, src, len, dst, crlf, checksafe);
if (ret) {
src = dst->buf;
len = dst->len;
}
return ret | ident_to_git(path, src, len, dst, ident);
}
int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
{
struct git_attr_check check[3];
int crlf = CRLF_GUESS;
int ident = 0, ret = 0;
const char *filter = NULL;
setup_convert_check(check);
if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->smudge)
filter = drv->smudge;
}
ret |= ident_to_worktree(path, src, len, dst, ident);
if (ret) {
src = dst->buf;
len = dst->len;
}
ret |= crlf_to_worktree(path, src, len, dst, crlf);
if (ret) {
src = dst->buf;
len = dst->len;
}
return ret | apply_filter(path, src, len, dst, filter);
}