Implement filter expression to bytecode compiler in liblttng-ctl

[lttng-tools.git] / src / lib / lttng-ctl / filter-bytecode.h

diff --git a/src/lib/lttng-ctl/filter-bytecode.h b/src/lib/lttng-ctl/filter-bytecode.h
new file mode 100644 (file)
index 0000000..fc2d6c8
--- /dev/null
+++ b/src/lib/lttng-ctl/filter-bytecode.h
@@ -0,0 +1,148 @@
+#ifndef _FILTER_BYTECODE_H
+#define _FILTER_BYTECODE_H
+
+/*
+ * filter-bytecode.h
+ *
+ * LTTng filter bytecode
+ *
+ * Copyright 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "filter-ast.h"
+
+/*
+ * offsets are absolute from start of bytecode.
+ */
+
+enum filter_register {
+       REG_R0 = 0,
+       REG_R1 = 1,
+       REG_ERROR,
+};
+
+enum field_ref_type {
+       FIELD_REF_UNKNOWN = 0,
+       FIELD_REF_STRING,
+       FIELD_REF_SEQUENCE,
+       FIELD_REF_S64,
+};
+
+struct field_ref {
+       /* Initially, symbol offset. After link, field offset. */
+       uint16_t offset;
+       uint8_t type;   /* enum field_ref_type */
+} __attribute__((packed));
+
+struct literal_numeric {
+       int64_t v;
+} __attribute__((packed));
+
+struct literal_string {
+       char string[0];
+} __attribute__((packed));
+
+enum filter_op {
+       FILTER_OP_UNKNOWN = 0,
+
+       FILTER_OP_RETURN,
+
+       /* binary */
+       FILTER_OP_MUL,
+       FILTER_OP_DIV,
+       FILTER_OP_MOD,
+       FILTER_OP_PLUS,
+       FILTER_OP_MINUS,
+       FILTER_OP_RSHIFT,
+       FILTER_OP_LSHIFT,
+       FILTER_OP_BIN_AND,
+       FILTER_OP_BIN_OR,
+       FILTER_OP_BIN_XOR,
+       FILTER_OP_EQ,
+       FILTER_OP_NE,
+       FILTER_OP_GT,
+       FILTER_OP_LT,
+       FILTER_OP_GE,
+       FILTER_OP_LE,
+
+       /* unary */
+       FILTER_OP_UNARY_PLUS,
+       FILTER_OP_UNARY_MINUS,
+       FILTER_OP_UNARY_NOT,
+
+       /* logical */
+       FILTER_OP_AND,
+       FILTER_OP_OR,
+
+       /* load */
+       FILTER_OP_LOAD_FIELD_REF,
+       FILTER_OP_LOAD_STRING,
+       FILTER_OP_LOAD_S64,
+
+       NR_FILTER_OPS,
+};
+
+typedef uint8_t filter_opcode_t;
+
+struct load_op {
+       filter_opcode_t op;
+       uint8_t reg;            /* enum filter_register */
+       char data[0];
+       /* data to load. Size known by enum filter_opcode and null-term char. */
+} __attribute__((packed));
+
+struct binary_op {
+       filter_opcode_t op;
+} __attribute__((packed));
+
+struct unary_op {
+       filter_opcode_t op;
+       uint8_t reg;            /* enum filter_register */
+} __attribute__((packed));
+
+/* skip_offset is absolute from start of bytecode */
+struct logical_op {
+       filter_opcode_t op;
+       uint16_t skip_offset;   /* bytecode insn, if skip second test */
+} __attribute__((packed));
+
+struct return_op {
+       filter_opcode_t op;
+} __attribute__((packed));
+
+/*
+ * The reloc table is located at the end of the bytecode. It is made of
+ * tuples: (uint16_t, var. len. string). It starts at
+ * reloc_table_offset.
+ */
+struct filter_bytecode {
+       uint16_t len;
+       uint16_t reloc_table_offset;
+       char data[0];
+};
+
+struct filter_bytecode_alloc {
+       uint16_t alloc_len;
+       struct filter_bytecode b;
+};
+
+static inline
+unsigned int bytecode_get_len(struct filter_bytecode *bytecode)
+{
+       return bytecode->len;
+}
+
+#endif /* _FILTER_BYTECODE_H */