From: Simon Marchi <simon.marchi@efficios.com>
Date: Mon, 6 Apr 2020 20:43:09 +0000 (-0400)
Subject: common: add more bytecode helpers
X-Git-Tag: v2.13.0-rc1~262
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=6afbab01c56b1a634c7071e1e885759ac4fd0b7f;p=lttng-tools.git

common: add more bytecode helpers

The common/bytecode/bytecode.c file already contains some helper
functions that are used build bytecode. A following patch will require
helpers for a few more operations. This patch factors them out of the
filter-visitor-generate-bytecode.c file.

No functional changes intended.

Change-Id: I013e0dad3e0264d062e3e8733c05f7fbb4bda70c
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Depends-on: lttng-ust: I5a800fc92e588c2a6a0e26282b0ad5f31c044479
---

diff --git a/src/common/bytecode/bytecode.c b/src/common/bytecode/bytecode.c
index 4f8c325b5..fb8985a00 100644
--- a/src/common/bytecode/bytecode.c
+++ b/src/common/bytecode/bytecode.c
@@ -100,6 +100,155 @@ int bytecode_push_logical(struct lttng_bytecode_alloc **fb,
 	return 0;
 }
 
+LTTNG_HIDDEN
+int bytecode_push_get_payload_root(struct lttng_bytecode_alloc **bytecode)
+{
+	int ret;
+	struct load_op *insn;
+	const uint32_t insn_len = sizeof(struct load_op);
+
+	insn = calloc(insn_len, 1);
+	if (!insn) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	insn->op = BYTECODE_OP_GET_PAYLOAD_ROOT;
+	ret = bytecode_push(bytecode, insn, 1, insn_len);
+	free(insn);
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+int bytecode_push_get_context_root(struct lttng_bytecode_alloc **bytecode)
+{
+	int ret;
+	struct load_op *insn;
+	const uint32_t insn_len = sizeof(struct load_op);
+
+	insn = calloc(insn_len, 1);
+	if (!insn) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	insn->op = BYTECODE_OP_GET_CONTEXT_ROOT;
+	ret = bytecode_push(bytecode, insn, 1, insn_len);
+	free(insn);
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+int bytecode_push_get_app_context_root(struct lttng_bytecode_alloc **bytecode)
+{
+	int ret;
+	struct load_op *insn;
+	const uint32_t insn_len = sizeof(struct load_op);
+
+	insn = calloc(insn_len, 1);
+	if (!insn) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	insn->op = BYTECODE_OP_GET_APP_CONTEXT_ROOT;
+	ret = bytecode_push(bytecode, insn, 1, insn_len);
+	free(insn);
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+int bytecode_push_get_index_u64(struct lttng_bytecode_alloc **bytecode,
+		uint64_t index)
+{
+	int ret;
+	struct load_op *insn;
+	struct get_index_u64 index_op_data;
+	const uint32_t insn_len =
+			sizeof(struct load_op) + sizeof(struct get_index_u64);
+
+	insn = calloc(insn_len, 1);
+	if (!insn) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	insn->op = BYTECODE_OP_GET_INDEX_U64;
+	index_op_data.index = index;
+	memcpy(insn->data, &index_op_data, sizeof(index));
+	ret = bytecode_push(bytecode, insn, 1, insn_len);
+
+	free(insn);
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+int bytecode_push_get_symbol(struct lttng_bytecode_alloc **bytecode,
+		struct lttng_bytecode_alloc **bytecode_reloc,
+		const char *symbol)
+{
+	int ret;
+	struct load_op *insn;
+	struct get_symbol symbol_offset;
+	uint32_t reloc_offset_u32;
+	uint16_t reloc_offset;
+	uint32_t bytecode_reloc_offset_u32;
+	const uint32_t insn_len =
+			sizeof(struct load_op) + sizeof(struct get_symbol);
+
+	insn = calloc(insn_len, 1);
+	if (!insn) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	insn->op = BYTECODE_OP_GET_SYMBOL;
+
+	/*
+	 * Get offset in the reloc portion at which the symbol name
+	 * will end up at (GET_SYMBOL's operand points there).
+	 */
+	bytecode_reloc_offset_u32 = bytecode_get_len(&(*bytecode_reloc)->b) +
+			sizeof(reloc_offset);
+	symbol_offset.offset = (uint16_t) bytecode_reloc_offset_u32;
+	memcpy(insn->data, &symbol_offset, sizeof(symbol_offset));
+
+	/*
+	 * Get offset in the bytecode where the opcode will end up at,
+	 * the reloc offset points to it.
+	 */
+	reloc_offset_u32 = bytecode_get_len(&(*bytecode)->b);
+	if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
+		ret = -EINVAL;
+		goto end;
+	}
+	reloc_offset = (uint16_t) reloc_offset_u32;
+
+	/* Append op in bytecode. */
+	ret = bytecode_push(bytecode, insn, 1, insn_len);
+	if (ret) {
+		goto end;
+	}
+
+	/* Append reloc offset. */
+	ret = bytecode_push(bytecode_reloc, &reloc_offset,
+			1, sizeof(reloc_offset));
+	if (ret) {
+		goto end;
+	}
+
+	/* Append symbol name. */
+	ret = bytecode_push(bytecode_reloc, symbol, 1, strlen(symbol) + 1);
+
+end:
+	free(insn);
+	return ret;
+}
+
 /*
  * Allocate an lttng_bytecode object and copy the given original bytecode.
  *
diff --git a/src/common/bytecode/bytecode.h b/src/common/bytecode/bytecode.h
index 151ca8a0f..498f7f000 100644
--- a/src/common/bytecode/bytecode.h
+++ b/src/common/bytecode/bytecode.h
@@ -245,6 +245,19 @@ LTTNG_HIDDEN int bytecode_push_logical(struct lttng_bytecode_alloc **fb,
 LTTNG_HIDDEN struct lttng_bytecode *lttng_bytecode_copy(
 		const struct lttng_bytecode *orig_f);
 
+LTTNG_HIDDEN int bytecode_push_get_payload_root(
+		struct lttng_bytecode_alloc **bytecode);
+LTTNG_HIDDEN int bytecode_push_get_context_root(
+		struct lttng_bytecode_alloc **bytecode);
+LTTNG_HIDDEN int bytecode_push_get_app_context_root(
+		struct lttng_bytecode_alloc **bytecode);
+LTTNG_HIDDEN int bytecode_push_get_index_u64(
+		struct lttng_bytecode_alloc **bytecode, uint64_t index);
+LTTNG_HIDDEN int bytecode_push_get_symbol(
+		struct lttng_bytecode_alloc **bytecode,
+		struct lttng_bytecode_alloc **bytecode_reloc,
+		const char *symbol);
+
 static inline
 unsigned int bytecode_get_len(struct lttng_bytecode *bytecode)
 {
diff --git a/src/common/filter/filter-visitor-generate-bytecode.c b/src/common/filter/filter-visitor-generate-bytecode.c
index 51ebad130..e0ba9fd0a 100644
--- a/src/common/filter/filter-visitor-generate-bytecode.c
+++ b/src/common/filter/filter-visitor-generate-bytecode.c
@@ -240,124 +240,55 @@ int visit_node_load_expression(struct filter_parser_ctx *ctx,
 		switch (op->type) {
 		case IR_LOAD_EXPRESSION_GET_CONTEXT_ROOT:
 		{
-			struct load_op *insn;
-			uint32_t insn_len = sizeof(struct load_op);
-			int ret;
+			const int ret = bytecode_push_get_context_root(&ctx->bytecode);
 
-			insn = calloc(insn_len, 1);
-			if (!insn)
-				return -ENOMEM;
-			insn->op = BYTECODE_OP_GET_CONTEXT_ROOT;
-			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
-			free(insn);
 			if (ret) {
 				return ret;
 			}
+
 			break;
 		}
 		case IR_LOAD_EXPRESSION_GET_APP_CONTEXT_ROOT:
 		{
-			struct load_op *insn;
-			uint32_t insn_len = sizeof(struct load_op);
-			int ret;
+			const int ret = bytecode_push_get_app_context_root(&ctx->bytecode);
 
-			insn = calloc(insn_len, 1);
-			if (!insn)
-				return -ENOMEM;
-			insn->op = BYTECODE_OP_GET_APP_CONTEXT_ROOT;
-			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
-			free(insn);
 			if (ret) {
 				return ret;
 			}
+
 			break;
 		}
 		case IR_LOAD_EXPRESSION_GET_PAYLOAD_ROOT:
 		{
-			struct load_op *insn;
-			uint32_t insn_len = sizeof(struct load_op);
-			int ret;
+			const int ret = bytecode_push_get_payload_root(&ctx->bytecode);
 
-			insn = calloc(insn_len, 1);
-			if (!insn)
-				return -ENOMEM;
-			insn->op = BYTECODE_OP_GET_PAYLOAD_ROOT;
-			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
-			free(insn);
 			if (ret) {
 				return ret;
 			}
+
 			break;
 		}
 		case IR_LOAD_EXPRESSION_GET_SYMBOL:
 		{
-			struct load_op *insn;
-			uint32_t insn_len = sizeof(struct load_op)
-				+ sizeof(struct get_symbol);
-			struct get_symbol symbol_offset;
-			uint32_t reloc_offset_u32;
-			uint16_t reloc_offset;
-			uint32_t bytecode_reloc_offset_u32;
-			int ret;
+			const int ret = bytecode_push_get_symbol(
+					&ctx->bytecode,
+					&ctx->bytecode_reloc,
+					op->u.symbol);
 
-			insn = calloc(insn_len, 1);
-			if (!insn)
-				return -ENOMEM;
-			insn->op = BYTECODE_OP_GET_SYMBOL;
-			bytecode_reloc_offset_u32 =
-					bytecode_get_len(&ctx->bytecode_reloc->b)
-					+ sizeof(reloc_offset);
-			symbol_offset.offset =
-					(uint16_t) bytecode_reloc_offset_u32;
-			memcpy(insn->data, &symbol_offset,
-					sizeof(symbol_offset));
-			/* reloc_offset points to struct load_op */
-			reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
-			if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
-				free(insn);
-				return -EINVAL;
-			}
-			reloc_offset = (uint16_t) reloc_offset_u32;
-			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
-			if (ret) {
-				free(insn);
-				return ret;
-			}
-			/* append reloc */
-			ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
-					1, sizeof(reloc_offset));
-			if (ret) {
-				free(insn);
-				return ret;
-			}
-			ret = bytecode_push(&ctx->bytecode_reloc,
-					op->u.symbol,
-					1, strlen(op->u.symbol) + 1);
-			free(insn);
 			if (ret) {
 				return ret;
 			}
+
 			break;
 		}
 		case IR_LOAD_EXPRESSION_GET_INDEX:
 		{
-			struct load_op *insn;
-			uint32_t insn_len = sizeof(struct load_op)
-				+ sizeof(struct get_index_u64);
-			struct get_index_u64 index;
-			int ret;
+			const int ret = bytecode_push_get_index_u64(&ctx->bytecode, op->u.index);
 
-			insn = calloc(insn_len, 1);
-			if (!insn)
-				return -ENOMEM;
-			insn->op = BYTECODE_OP_GET_INDEX_U64;
-			index.index = op->u.index;
-			memcpy(insn->data, &index, sizeof(index));
-			ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
-			free(insn);
 			if (ret) {
 				return ret;
 			}
+
 			break;
 		}
 		case IR_LOAD_EXPRESSION_LOAD_FIELD: