git/xdiff-interface.c
Brandon Casey 563d5a2c84 xdiff-interface.c: strip newline (and cr) from line before pattern matching
POSIX doth sayeth:

   "In the regular expression processing described in IEEE Std 1003.1-2001,
    the <newline> is regarded as an ordinary character and both a period and
    a non-matching list can match one. ... Those utilities (like grep) that
    do not allow <newline>s to match are responsible for eliminating any
    <newline> from strings before matching against the RE."

Thus far git has not been removing the trailing newline from strings matched
against regular expression patterns. This has the effect that (quoting
Jonathan del Strother) "... a line containing just 'FUNCNAME' (terminated by
a newline) will be matched by the pattern '^(FUNCNAME.$)' but not
'^(FUNCNAME$)'", and more simply not '^FUNCNAME$'.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-16 08:31:56 -07:00

250 lines
5.5 KiB
C

#include "cache.h"
#include "xdiff-interface.h"
static int parse_num(char **cp_p, int *num_p)
{
char *cp = *cp_p;
int num = 0;
int read_some;
while ('0' <= *cp && *cp <= '9')
num = num * 10 + *cp++ - '0';
if (!(read_some = 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, s, this_size);
size -= this_size;
s += this_size;
}
}
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 */
priv->remainder = xrealloc(priv->remainder,
priv->remainder_size +
mb[i].size);
memcpy(priv->remainder + priv->remainder_size,
mb[i].ptr, mb[i].size);
priv->remainder_size += mb[i].size;
continue;
}
/* we have a complete line */
if (!priv->remainder) {
consume_one(priv, mb[i].ptr, mb[i].size);
continue;
}
priv->remainder = xrealloc(priv->remainder,
priv->remainder_size +
mb[i].size);
memcpy(priv->remainder + priv->remainder_size,
mb[i].ptr, mb[i].size);
consume_one(priv, priv->remainder,
priv->remainder_size + mb[i].size);
free(priv->remainder);
priv->remainder = NULL;
priv->remainder_size = 0;
}
if (priv->remainder) {
consume_one(priv, priv->remainder, priv->remainder_size);
free(priv->remainder);
priv->remainder = NULL;
priv->remainder_size = 0;
}
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 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 result = 0, i;
/* 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 (reg->negate ^ !!regexec(&reg->re,
line_buffer, 2, pmatch, 0)) {
free(line_buffer);
return -1;
}
}
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]) ||
line[result - 1] == '\n'))
result--;
memcpy(buffer, line, result);
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);
free(buffer);
value = ep + 1;
}
}