From: Junio C Hamano <gitster@xxxxxxxxx>
Our "grep" allows complex boolean expressions to be formed to match
each individual line with operators like --and, '(', ')' and --not.
Introduce the "--debug" option to show the parse tree to help people
who want to debug and enhance it.
Also "log" learns "--debug-grep" option to do the same. The command
line parser to the log family is a lot more limited than the general
"git grep" parser, but it has special handling for header matching
(e.g. "--author"), and a parse tree is valuable when working on it.
Note that "--all-match" is *not* any individual node in the parse
tree. It is an instruction to the evaluator to check all the nodes
in the top-level backbone have matched and reject a document as
non-matching otherwise.
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
Signed-off-by: Michael J Gruber <git@xxxxxxxxxxxxxxxxxxxx>
---
builtin/grep.c | 3 ++
grep.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
grep.h | 1 +
revision.c | 2 ++
4 files changed, 96 insertions(+), 2 deletions(-)
diff --git a/builtin/grep.c b/builtin/grep.c
index fe1726f..8aea00c 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -772,6 +772,9 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
"indicate hit with exit status without output"),
OPT_BOOLEAN(0, "all-match", &opt.all_match,
"show only matches from files that match all patterns"),
+ { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
+ "show parse tree for grep expression",
+ PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
OPT_GROUP(""),
{ OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
"pager", "show matching files in the pager",
diff --git a/grep.c b/grep.c
index 04e3ec6..be15c47 100644
--- a/grep.c
+++ b/grep.c
@@ -332,6 +332,87 @@ static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
return compile_pattern_or(list);
}
+static void indent(int in)
+{
+ while (in-- > 0)
+ fputc(' ', stderr);
+}
+
+static void dump_grep_pat(struct grep_pat *p)
+{
+ switch (p->token) {
+ case GREP_AND: fprintf(stderr, "*and*"); break;
+ case GREP_OPEN_PAREN: fprintf(stderr, "*(*"); break;
+ case GREP_CLOSE_PAREN: fprintf(stderr, "*)*"); break;
+ case GREP_NOT: fprintf(stderr, "*not*"); break;
+ case GREP_OR: fprintf(stderr, "*or*"); break;
+
+ case GREP_PATTERN: fprintf(stderr, "pattern"); break;
+ case GREP_PATTERN_HEAD: fprintf(stderr, "pattern_head"); break;
+ case GREP_PATTERN_BODY: fprintf(stderr, "pattern_body"); break;
+ }
+
+ switch (p->token) {
+ default: break;
+ case GREP_PATTERN_HEAD:
+ fprintf(stderr, "<head %d>", p->field); break;
+ case GREP_PATTERN_BODY:
+ fprintf(stderr, "<body>"); break;
+ }
+ switch (p->token) {
+ default: break;
+ case GREP_PATTERN_HEAD:
+ case GREP_PATTERN_BODY:
+ case GREP_PATTERN:
+ fprintf(stderr, "%.*s", (int)p->patternlen, p->pattern);
+ break;
+ }
+ fputc('\n', stderr);
+}
+
+static void dump_grep_expression_1(struct grep_expr *x, int in)
+{
+ indent(in);
+ switch (x->node) {
+ case GREP_NODE_TRUE:
+ fprintf(stderr, "true\n");
+ break;
+ case GREP_NODE_ATOM:
+ dump_grep_pat(x->u.atom);
+ break;
+ case GREP_NODE_NOT:
+ fprintf(stderr, "(not\n");
+ dump_grep_expression_1(x->u.unary, in+1);
+ indent(in);
+ fprintf(stderr, ")\n");
+ break;
+ case GREP_NODE_AND:
+ fprintf(stderr, "(and\n");
+ dump_grep_expression_1(x->u.binary.left, in+1);
+ dump_grep_expression_1(x->u.binary.right, in+1);
+ indent(in);
+ fprintf(stderr, ")\n");
+ break;
+ case GREP_NODE_OR:
+ fprintf(stderr, "(or\n");
+ dump_grep_expression_1(x->u.binary.left, in+1);
+ dump_grep_expression_1(x->u.binary.right, in+1);
+ indent(in);
+ fprintf(stderr, ")\n");
+ break;
+ }
+}
+
+void dump_grep_expression(struct grep_opt *opt)
+{
+ struct grep_expr *x = opt->pattern_expression;
+
+ if (opt->all_match)
+ fprintf(stderr, "[all-match]\n");
+ dump_grep_expression_1(x, 0);
+ fflush(NULL);
+}
+
static struct grep_expr *grep_true_expr(void)
{
struct grep_expr *z = xcalloc(1, sizeof(*z));
@@ -395,7 +476,7 @@ static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
return header_expr;
}
-void compile_grep_patterns(struct grep_opt *opt)
+static void compile_grep_patterns_real(struct grep_opt *opt)
{
struct grep_pat *p;
struct grep_expr *header_expr = prep_header_patterns(opt);
@@ -415,7 +496,7 @@ void compile_grep_patterns(struct grep_opt *opt)
if (opt->all_match || header_expr)
opt->extended = 1;
- else if (!opt->extended)
+ else if (!opt->extended && !opt->debug)
return;
p = opt->pattern_list;
@@ -435,6 +516,13 @@ void compile_grep_patterns(struct grep_opt *opt)
opt->all_match = 1;
}
+void compile_grep_patterns(struct grep_opt *opt)
+{
+ compile_grep_patterns_real(opt);
+ if (opt->debug)
+ dump_grep_expression(opt);
+}
+
static void free_pattern_expr(struct grep_expr *x)
{
switch (x->node) {
diff --git a/grep.h b/grep.h
index ed7de6b..bf5be5a 100644
--- a/grep.h
+++ b/grep.h
@@ -90,6 +90,7 @@ struct grep_opt {
int word_regexp;
int fixed;
int all_match;
+ int debug;
#define GREP_BINARY_DEFAULT 0
#define GREP_BINARY_NOMATCH 1
#define GREP_BINARY_TEXT 2
diff --git a/revision.c b/revision.c
index 9a0d9c7..90376e8 100644
--- a/revision.c
+++ b/revision.c
@@ -1578,6 +1578,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
} else if ((argcount = parse_long_opt("grep", argv, &optarg))) {
add_message_grep(revs, optarg);
return argcount;
+ } else if (!strcmp(arg, "--grep-debug")) {
+ revs->grep_filter.debug = 1;
} else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
revs->grep_filter.regflags |= REG_EXTENDED;
} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
--
1.7.12.592.g41e7905
--
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