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-rw-r--r--grep.c102
1 files changed, 71 insertions, 31 deletions
diff --git a/grep.c b/grep.c
index 82fb349be6..63c4280cac 100644
--- a/grep.c
+++ b/grep.c
@@ -189,30 +189,74 @@ static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
return compile_pattern_or(list);
}
-void compile_grep_patterns(struct grep_opt *opt)
+static struct grep_expr *grep_true_expr(void)
+{
+ struct grep_expr *z = xcalloc(1, sizeof(*z));
+ z->node = GREP_NODE_TRUE;
+ return z;
+}
+
+static struct grep_expr *grep_or_expr(struct grep_expr *left, struct grep_expr *right)
+{
+ struct grep_expr *z = xcalloc(1, sizeof(*z));
+ z->node = GREP_NODE_OR;
+ z->u.binary.left = left;
+ z->u.binary.right = right;
+ return z;
+}
+
+static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
{
struct grep_pat *p;
- struct grep_expr *header_expr = NULL;
-
- if (opt->header_list) {
- p = opt->header_list;
- header_expr = compile_pattern_expr(&p);
- if (p)
- die("incomplete pattern expression: %s", p->pattern);
- for (p = opt->header_list; p; p = p->next) {
- switch (p->token) {
- case GREP_PATTERN: /* atom */
- case GREP_PATTERN_HEAD:
- case GREP_PATTERN_BODY:
- compile_regexp(p, opt);
- break;
- default:
- opt->extended = 1;
- break;
- }
+ struct grep_expr *header_expr;
+ struct grep_expr *(header_group[GREP_HEADER_FIELD_MAX]);
+ enum grep_header_field fld;
+
+ if (!opt->header_list)
+ return NULL;
+ p = opt->header_list;
+ for (p = opt->header_list; p; p = p->next) {
+ if (p->token != GREP_PATTERN_HEAD)
+ die("bug: a non-header pattern in grep header list.");
+ if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
+ die("bug: unknown header field %d", p->field);
+ compile_regexp(p, opt);
+ }
+
+ for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++)
+ header_group[fld] = NULL;
+
+ for (p = opt->header_list; p; p = p->next) {
+ struct grep_expr *h;
+ struct grep_pat *pp = p;
+
+ h = compile_pattern_atom(&pp);
+ if (!h || pp != p->next)
+ die("bug: malformed header expr");
+ if (!header_group[p->field]) {
+ header_group[p->field] = h;
+ continue;
}
+ header_group[p->field] = grep_or_expr(h, header_group[p->field]);
}
+ header_expr = NULL;
+
+ for (fld = 0; fld < GREP_HEADER_FIELD_MAX; fld++) {
+ if (!header_group[fld])
+ continue;
+ if (!header_expr)
+ header_expr = grep_true_expr();
+ header_expr = grep_or_expr(header_group[fld], header_expr);
+ }
+ return header_expr;
+}
+
+void compile_grep_patterns(struct grep_opt *opt)
+{
+ struct grep_pat *p;
+ struct grep_expr *header_expr = prep_header_patterns(opt);
+
for (p = opt->pattern_list; p; p = p->next) {
switch (p->token) {
case GREP_PATTERN: /* atom */
@@ -231,9 +275,6 @@ void compile_grep_patterns(struct grep_opt *opt)
else if (!opt->extended)
return;
- /* Then bundle them up in an expression.
- * A classic recursive descent parser would do.
- */
p = opt->pattern_list;
if (p)
opt->pattern_expression = compile_pattern_expr(&p);
@@ -243,22 +284,18 @@ void compile_grep_patterns(struct grep_opt *opt)
if (!header_expr)
return;
- if (opt->pattern_expression) {
- struct grep_expr *z;
- z = xcalloc(1, sizeof(*z));
- z->node = GREP_NODE_OR;
- z->u.binary.left = opt->pattern_expression;
- z->u.binary.right = header_expr;
- opt->pattern_expression = z;
- } else {
+ if (!opt->pattern_expression)
opt->pattern_expression = header_expr;
- }
+ else
+ opt->pattern_expression = grep_or_expr(opt->pattern_expression,
+ header_expr);
opt->all_match = 1;
}
static void free_pattern_expr(struct grep_expr *x)
{
switch (x->node) {
+ case GREP_NODE_TRUE:
case GREP_NODE_ATOM:
break;
case GREP_NODE_NOT:
@@ -487,6 +524,9 @@ static int match_expr_eval(struct grep_expr *x, char *bol, char *eol,
if (!x)
die("Not a valid grep expression");
switch (x->node) {
+ case GREP_NODE_TRUE:
+ h = 1;
+ break;
case GREP_NODE_ATOM:
h = match_one_pattern(x->u.atom, bol, eol, ctx, &match, 0);
break;