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-rw-r--r--convert.c629
1 files changed, 629 insertions, 0 deletions
diff --git a/convert.c b/convert.c
new file mode 100644
index 0000000000..78efed800d
--- /dev/null
+++ b/convert.c
@@ -0,0 +1,629 @@
+#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;
+ 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 */
+
+ strbuf_init(&nbuf, 0);
+ 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);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 08:34:35 +0000