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Update grep internal for grepping only in head/body

This further updates the built-in grep engine so that we can say
something like "this pattern should match only in head".  This
can be used to simplify grepping in the log messages.

Signed-off-by: Junio C Hamano <junkio@cox.net>
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1 parent a2ed6ae commit 480c1ca6fd8df58a783e231648b489ed2bfd17f1 Junio C Hamano committed Sep 20, 2006
Showing with 42 additions and 16 deletions.
  1. +35 −16 grep.c
  2. +7 −0 grep.h
View
51 grep.c
@@ -43,6 +43,8 @@ static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
p = *list;
switch (p->token) {
case GREP_PATTERN: /* atom */
+ case GREP_PATTERN_HEAD:
+ case GREP_PATTERN_BODY:
x = xcalloc(1, sizeof (struct grep_expr));
x->node = GREP_NODE_ATOM;
x->u.atom = p;
@@ -141,10 +143,16 @@ void compile_grep_patterns(struct grep_opt *opt)
/* First compile regexps */
for (p = opt->pattern_list; p; p = p->next) {
- if (p->token == GREP_PATTERN)
+ switch (p->token) {
+ case GREP_PATTERN: /* atom */
+ case GREP_PATTERN_HEAD:
+ case GREP_PATTERN_BODY:
compile_regexp(p, opt);
- else
+ break;
+ default:
opt->extended = 1;
+ break;
+ }
}
if (!opt->extended)
@@ -210,12 +218,16 @@ static int fixmatch(const char *pattern, char *line, regmatch_t *match)
}
}
-static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol)
+static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol, enum grep_context ctx)
{
int hit = 0;
int at_true_bol = 1;
regmatch_t pmatch[10];
+ if ((p->token != GREP_PATTERN) &&
+ ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
+ return 0;
+
again:
if (!opt->fixed) {
regex_t *exp = &p->regexp;
@@ -262,37 +274,40 @@ static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol
static int match_expr_eval(struct grep_opt *opt,
struct grep_expr *x,
- char *bol, char *eol)
+ char *bol, char *eol,
+ enum grep_context ctx)
{
switch (x->node) {
case GREP_NODE_ATOM:
- return match_one_pattern(opt, x->u.atom, bol, eol);
+ return match_one_pattern(opt, x->u.atom, bol, eol, ctx);
break;
case GREP_NODE_NOT:
- return !match_expr_eval(opt, x->u.unary, bol, eol);
+ return !match_expr_eval(opt, x->u.unary, bol, eol, ctx);
case GREP_NODE_AND:
- return (match_expr_eval(opt, x->u.binary.left, bol, eol) &&
- match_expr_eval(opt, x->u.binary.right, bol, eol));
+ return (match_expr_eval(opt, x->u.binary.left, bol, eol, ctx) &&
+ match_expr_eval(opt, x->u.binary.right, bol, eol, ctx));
case GREP_NODE_OR:
- return (match_expr_eval(opt, x->u.binary.left, bol, eol) ||
- match_expr_eval(opt, x->u.binary.right, bol, eol));
+ return (match_expr_eval(opt, x->u.binary.left, bol, eol, ctx) ||
+ match_expr_eval(opt, x->u.binary.right, bol, eol, ctx));
}
die("Unexpected node type (internal error) %d\n", x->node);
}
-static int match_expr(struct grep_opt *opt, char *bol, char *eol)
+static int match_expr(struct grep_opt *opt, char *bol, char *eol,
+ enum grep_context ctx)
{
struct grep_expr *x = opt->pattern_expression;
- return match_expr_eval(opt, x, bol, eol);
+ return match_expr_eval(opt, x, bol, eol, ctx);
}
-static int match_line(struct grep_opt *opt, char *bol, char *eol)
+static int match_line(struct grep_opt *opt, char *bol, char *eol,
+ enum grep_context ctx)
{
struct grep_pat *p;
if (opt->extended)
- return match_expr(opt, bol, eol);
+ return match_expr(opt, bol, eol, ctx);
for (p = opt->pattern_list; p; p = p->next) {
- if (match_one_pattern(opt, p, bol, eol))
+ if (match_one_pattern(opt, p, bol, eol, ctx))
return 1;
}
return 0;
@@ -312,6 +327,7 @@ int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long
int binary_match_only = 0;
const char *hunk_mark = "";
unsigned count = 0;
+ enum grep_context ctx = GREP_CONTEXT_HEAD;
if (buffer_is_binary(buf, size)) {
switch (opt->binary) {
@@ -339,7 +355,10 @@ int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long
ch = *eol;
*eol = 0;
- hit = match_line(opt, bol, eol);
+ if ((ctx == GREP_CONTEXT_HEAD) && (eol == bol))
+ ctx = GREP_CONTEXT_BODY;
+
+ hit = match_line(opt, bol, eol, ctx);
*eol = ch;
/* "grep -v -e foo -e bla" should list lines
View
7 grep.h
@@ -3,13 +3,20 @@
enum grep_pat_token {
GREP_PATTERN,
+ GREP_PATTERN_HEAD,
+ GREP_PATTERN_BODY,
GREP_AND,
GREP_OPEN_PAREN,
GREP_CLOSE_PAREN,
GREP_NOT,
GREP_OR,
};
+enum grep_context {
+ GREP_CONTEXT_HEAD,
+ GREP_CONTEXT_BODY,
+};
+
struct grep_pat {
struct grep_pat *next;
const char *origin;

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