git-commit-vandalism/xdiff-interface.c

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#include "cache.h"
#include "xdiff-interface.h"
#include "xdiff/xtypes.h"
#include "xdiff/xdiffi.h"
#include "xdiff/xemit.h"
#include "xdiff/xmacros.h"
struct xdiff_emit_state {
xdiff_emit_consume_fn consume;
void *consume_callback_data;
struct strbuf remainder;
};
static int parse_num(char **cp_p, int *num_p)
{
char *cp = *cp_p;
int num = 0;
while ('0' <= *cp && *cp <= '9')
num = num * 10 + *cp++ - '0';
if (!(cp - *cp_p))
return -1;
*cp_p = cp;
*num_p = num;
return 0;
}
int parse_hunk_header(char *line, int len,
int *ob, int *on,
int *nb, int *nn)
{
char *cp;
cp = line + 4;
if (parse_num(&cp, ob)) {
bad_line:
return error("malformed diff output: %s", line);
}
if (*cp == ',') {
cp++;
if (parse_num(&cp, on))
goto bad_line;
}
else
*on = 1;
if (*cp++ != ' ' || *cp++ != '+')
goto bad_line;
if (parse_num(&cp, nb))
goto bad_line;
if (*cp == ',') {
cp++;
if (parse_num(&cp, nn))
goto bad_line;
}
else
*nn = 1;
return -!!memcmp(cp, " @@", 3);
}
static void consume_one(void *priv_, char *s, unsigned long size)
{
struct xdiff_emit_state *priv = priv_;
char *ep;
while (size) {
unsigned long this_size;
ep = memchr(s, '\n', size);
this_size = (ep == NULL) ? size : (ep - s + 1);
priv->consume(priv->consume_callback_data, s, this_size);
size -= this_size;
s += this_size;
}
}
static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
struct xdiff_emit_state *priv = priv_;
int i;
for (i = 0; i < nbuf; i++) {
if (mb[i].ptr[mb[i].size-1] != '\n') {
/* Incomplete line */
strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
continue;
}
/* we have a complete line */
if (!priv->remainder.len) {
consume_one(priv, mb[i].ptr, mb[i].size);
continue;
}
strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
consume_one(priv, priv->remainder.buf, priv->remainder.len);
strbuf_reset(&priv->remainder);
}
if (priv->remainder.len) {
consume_one(priv, priv->remainder.buf, priv->remainder.len);
strbuf_reset(&priv->remainder);
}
return 0;
}
/*
* Trim down common substring at the end of the buffers,
* but leave at least ctx lines at the end.
*/
static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
{
const int blk = 1024;
long trimmed = 0, recovered = 0;
char *ap = a->ptr + a->size;
char *bp = b->ptr + b->size;
long smaller = (a->size < b->size) ? a->size : b->size;
if (ctx)
return;
while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
trimmed += blk;
ap -= blk;
bp -= blk;
}
while (recovered < trimmed)
if (ap[recovered++] == '\n')
break;
a->size -= trimmed - recovered;
b->size -= trimmed - recovered;
}
int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
{
mmfile_t a = *mf1;
mmfile_t b = *mf2;
trim_common_tail(&a, &b, xecfg->ctxlen);
return xdl_diff(&a, &b, xpp, xecfg, xecb);
}
int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
xdiff_emit_consume_fn fn, void *consume_callback_data,
xpparam_t const *xpp,
xdemitconf_t const *xecfg, xdemitcb_t *xecb)
{
int ret;
struct xdiff_emit_state state;
memset(&state, 0, sizeof(state));
state.consume = fn;
state.consume_callback_data = consume_callback_data;
xecb->outf = xdiff_outf;
xecb->priv = &state;
strbuf_init(&state.remainder, 0);
ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
strbuf_release(&state.remainder);
return ret;
}
struct xdiff_emit_hunk_state {
xdiff_emit_hunk_consume_fn consume;
void *consume_callback_data;
};
static int process_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
xdemitconf_t const *xecfg)
{
long s1, s2, same, p_next, t_next;
xdchange_t *xch, *xche;
struct xdiff_emit_hunk_state *state = ecb->priv;
xdiff_emit_hunk_consume_fn fn = state->consume;
void *consume_callback_data = state->consume_callback_data;
for (xch = xscr; xch; xch = xche->next) {
xche = xdl_get_hunk(xch, xecfg);
s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
same = s2 + XDL_MAX(xch->i1 - s1, 0);
p_next = xche->i1 + xche->chg1;
t_next = xche->i2 + xche->chg2;
fn(consume_callback_data, same, p_next, t_next);
}
return 0;
}
int xdi_diff_hunks(mmfile_t *mf1, mmfile_t *mf2,
xdiff_emit_hunk_consume_fn fn, void *consume_callback_data,
xpparam_t const *xpp, xdemitconf_t *xecfg)
{
struct xdiff_emit_hunk_state state;
xdemitcb_t ecb;
memset(&state, 0, sizeof(state));
memset(&ecb, 0, sizeof(ecb));
state.consume = fn;
state.consume_callback_data = consume_callback_data;
xecfg->emit_func = (void (*)())process_diff;
ecb.priv = &state;
return xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
}
int read_mmfile(mmfile_t *ptr, const char *filename)
{
struct stat st;
FILE *f;
size_t sz;
if (stat(filename, &st))
return error("Could not stat %s", filename);
if ((f = fopen(filename, "rb")) == NULL)
return error("Could not open %s", filename);
sz = xsize_t(st.st_size);
ptr->ptr = xmalloc(sz ? sz : 1);
if (sz && fread(ptr->ptr, sz, 1, f) != 1)
return error("Could not read %s", filename);
fclose(f);
ptr->size = sz;
return 0;
}
#define FIRST_FEW_BYTES 8000
int buffer_is_binary(const char *ptr, unsigned long size)
{
if (FIRST_FEW_BYTES < size)
size = FIRST_FEW_BYTES;
return !!memchr(ptr, 0, size);
}
struct ff_regs {
int nr;
struct ff_reg {
regex_t re;
int negate;
} *array;
};
static long ff_regexp(const char *line, long len,
char *buffer, long buffer_size, void *priv)
{
char *line_buffer;
struct ff_regs *regs = priv;
regmatch_t pmatch[2];
int i;
int result = -1;
/* Exclude terminating newline (and cr) from matching */
if (len > 0 && line[len-1] == '\n') {
if (len > 1 && line[len-2] == '\r')
len -= 2;
else
len--;
}
line_buffer = xstrndup(line, len); /* make NUL terminated */
for (i = 0; i < regs->nr; i++) {
struct ff_reg *reg = regs->array + i;
if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
if (reg->negate)
goto fail;
break;
}
}
if (regs->nr <= i)
goto fail;
i = pmatch[1].rm_so >= 0 ? 1 : 0;
line += pmatch[i].rm_so;
result = pmatch[i].rm_eo - pmatch[i].rm_so;
if (result > buffer_size)
result = buffer_size;
else
while (result > 0 && (isspace(line[result - 1])))
result--;
memcpy(buffer, line, result);
fail:
free(line_buffer);
return result;
}
void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
{
int i;
struct ff_regs *regs;
xecfg->find_func = ff_regexp;
regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
for (i = 0, regs->nr = 1; value[i]; i++)
if (value[i] == '\n')
regs->nr++;
regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
for (i = 0; i < regs->nr; i++) {
struct ff_reg *reg = regs->array + i;
const char *ep = strchr(value, '\n'), *expression;
char *buffer = NULL;
reg->negate = (*value == '!');
if (reg->negate && i == regs->nr - 1)
die("Last expression must not be negated: %s", value);
if (*value == '!')
value++;
if (ep)
expression = buffer = xstrndup(value, ep - value);
else
expression = value;
if (regcomp(&reg->re, expression, cflags))
die("Invalid regexp to look for hunk header: %s", expression);
Avoid unnecessary "if-before-free" tests. This change removes all obvious useless if-before-free tests. E.g., it replaces code like this: if (some_expression) free (some_expression); with the now-equivalent: free (some_expression); It is equivalent not just because POSIX has required free(NULL) to work for a long time, but simply because it has worked for so long that no reasonable porting target fails the test. Here's some evidence from nearly 1.5 years ago: http://www.winehq.org/pipermail/wine-patches/2006-October/031544.html FYI, the change below was prepared by running the following: git ls-files -z | xargs -0 \ perl -0x3b -pi -e \ 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+(free\s*\(\s*\1\s*\))/$2/s' Note however, that it doesn't handle brace-enclosed blocks like "if (x) { free (x); }". But that's ok, since there were none like that in git sources. Beware: if you do use the above snippet, note that it can produce syntactically invalid C code. That happens when the affected "if"-statement has a matching "else". E.g., it would transform this if (x) free (x); else foo (); into this: free (x); else foo (); There were none of those here, either. If you're interested in automating detection of the useless tests, you might like the useless-if-before-free script in gnulib: [it *does* detect brace-enclosed free statements, and has a --name=S option to make it detect free-like functions with different names] http://git.sv.gnu.org/gitweb/?p=gnulib.git;a=blob;f=build-aux/useless-if-before-free Addendum: Remove one more (in imap-send.c), spotted by Jean-Luc Herren <jlh@gmx.ch>. Signed-off-by: Jim Meyering <meyering@redhat.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-31 18:26:32 +01:00
free(buffer);
value = ep + 1;
}
}
void xdiff_clear_find_func(xdemitconf_t *xecfg)
{
if (xecfg->find_func) {
int i;
struct ff_regs *regs = xecfg->find_func_priv;
for (i = 0; i < regs->nr; i++)
regfree(&regs->array[i].re);
free(regs->array);
free(regs);
xecfg->find_func = NULL;
xecfg->find_func_priv = NULL;
}
}
int git_xmerge_style = -1;
int git_xmerge_config(const char *var, const char *value, void *cb)
{
if (!strcasecmp(var, "merge.conflictstyle")) {
if (!value)
die("'%s' is not a boolean", var);
if (!strcmp(value, "diff3"))
git_xmerge_style = XDL_MERGE_DIFF3;
else if (!strcmp(value, "merge"))
git_xmerge_style = 0;
else
die("unknown style '%s' given for '%s'",
value, var);
return 0;
}
return git_default_config(var, value, cb);
}