[for-next][PATCH 44/46] tracing: Combine enum and arrays into single macro in filter code

Steven Rostedt
2018-03-21T02:22:40Z

[-- Attachment #1: 0044-tracing-Combine-enum-and-arrays-into-single-macro-in.patch --]
[-- Type: text/plain, Size: 4245 bytes --]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Instead of having a separate enum that is the index into another array, like
a string array, make a single macro that combines them into a single list,
and then the two can not get out of sync. This makes it easier to add and
remove items.

The macro trick is:

#define DOGS \
C( JACK, "Jack Russell") \
C( ITALIAN, "Italian Greyhound") \
C( GERMAN, "German Shepherd")

#undef C
#define C(a, b) a

enum { DOGS };

#undef C
#define C(a, b) b

static char dogs[] = { DOGS };

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 112 ++++++++++++++++---------------------
1 file changed, 48 insertions(+), 64 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c3c6eee1e4df..a2ef393b3bb2 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -33,22 +33,26 @@
"# Only events with the given fields will be affected.\n" \
"# If no events are modified, an error message will be displayed here"

-enum filter_op_ids
-{
- OP_OR,
- OP_AND,
- OP_GLOB,
- OP_NE,
- OP_EQ,
- OP_LT,
- OP_LE,
- OP_GT,
- OP_GE,
- OP_BAND,
- OP_NOT,
- OP_NONE,
- OP_OPEN_PAREN,
-};
+#define OPS \
+ C( OP_OR, "||", 1 ), \
+ C( OP_AND, "&&", 2 ), \
+ C( OP_GLOB, "~", 4 ), \
+ C( OP_NE, "!=", 4 ), \
+ C( OP_EQ, "==", 4 ), \
+ C( OP_LT, "<", 5 ), \
+ C( OP_LE, "<=", 5 ), \
+ C( OP_GT, ">", 5 ), \
+ C( OP_GE, ">=", 5 ), \
+ C( OP_BAND, "&", 6 ), \
+ C( OP_NOT, "!", 6 ), \
+ C( OP_NONE, "OP_NONE", 0 ), \
+ C( OP_OPEN_PAREN, "(", 0 ), \
+ C( OP_MAX, NULL, 0 )
+
+#undef C
+#define C(a, b, c) a
+
+enum filter_op_ids { OPS };

struct filter_op {
int id;
@@ -56,56 +60,36 @@ struct filter_op {
int precedence;
};

-/* Order must be the same as enum filter_op_ids above */
-static struct filter_op filter_ops[] = {
- { OP_OR, "||", 1 },
- { OP_AND, "&&", 2 },
- { OP_GLOB, "~", 4 },
- { OP_NE, "!=", 4 },
- { OP_EQ, "==", 4 },
- { OP_LT, "<", 5 },
- { OP_LE, "<=", 5 },
- { OP_GT, ">", 5 },
- { OP_GE, ">=", 5 },
- { OP_BAND, "&", 6 },
- { OP_NOT, "!", 6 },
- { OP_NONE, "OP_NONE", 0 },
- { OP_OPEN_PAREN, "(", 0 },
-};
+#undef C
+#define C(a, b, c) { a, b, c }

-enum {
- FILT_ERR_NONE,
- FILT_ERR_INVALID_OP,
- FILT_ERR_UNBALANCED_PAREN,
- FILT_ERR_TOO_MANY_OPERANDS,
- FILT_ERR_OPERAND_TOO_LONG,
- FILT_ERR_FIELD_NOT_FOUND,
- FILT_ERR_ILLEGAL_FIELD_OP,
- FILT_ERR_ILLEGAL_INTVAL,
- FILT_ERR_BAD_SUBSYS_FILTER,
- FILT_ERR_TOO_MANY_PREDS,
- FILT_ERR_MISSING_FIELD,
- FILT_ERR_INVALID_FILTER,
- FILT_ERR_IP_FIELD_ONLY,
- FILT_ERR_ILLEGAL_NOT_OP,
-};
+static struct filter_op filter_ops[] = { OPS };

-static char *err_text[] = {
- "No error",
- "Invalid operator",
- "Unbalanced parens",
- "Too many operands",
- "Operand too long",
- "Field not found",
- "Illegal operation for field type",
- "Illegal integer value",
- "Couldn't find or set field in one of a subsystem's events",
- "Too many terms in predicate expression",
- "Missing field name and/or value",
- "Meaningless filter expression",
- "Only 'ip' field is supported for function trace",
- "Illegal use of '!'",
-};
+#define ERRORS \
+ C( NONE, "No error"), \
+ C( INVALID_OP, "Invalid operator"), \
+ C( UNBALANCED_PAREN, "Unbalanced parens"), \
+ C( TOO_MANY_OPERANDS, "Too many operands"), \
+ C( OPERAND_TOO_LONG, "Operand too long"), \
+ C( FIELD_NOT_FOUND, "Field not found"), \
+ C( ILLEGAL_FIELD_OP, "Illegal operation for field type"), \
+ C( ILLEGAL_INTVAL, "Illegal integer value"), \
+ C( BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \
+ C( TOO_MANY_PREDS, "Too many terms in predicate expression"), \
+ C( MISSING_FIELD, "Missing field name and/or value"), \
+ C( INVALID_FILTER, "Meaningless filter expression"), \
+ C( IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \
+ C( ILLEGAL_NOT_OP, "Illegal use of '!'"),
+
+#undef C
+#define C(a, b) FILT_ERR_##a
+
+enum { ERRORS };
+
+#undef C
+#define C(a, b) b
+
+static char *err_text[] = { ERRORS };

struct opstack_op {
enum filter_op_ids op;
--
2.15.1