X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fevent-expr-to-bytecode.c;fp=src%2Fcommon%2Fevent-expr-to-bytecode.c;h=abc713fb3dba1227f1e914834602219570c2caca;hb=748b5f7b257748a094096ef2beeb2eb941324978;hp=0000000000000000000000000000000000000000;hpb=6afbab01c56b1a634c7071e1e885759ac4fd0b7f;p=lttng-tools.git

diff --git a/src/common/event-expr-to-bytecode.c b/src/common/event-expr-to-bytecode.c
new file mode 100644
index 000000000..abc713fb3
--- /dev/null
+++ b/src/common/event-expr-to-bytecode.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright 2020 EfficiOS, Inc.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include "event-expr-to-bytecode.h"
+
+#include <stdio.h>
+#include <lttng/event-expr.h>
+#include <common/bytecode/bytecode.h>
+#include <common/error.h>
+
+static
+int event_expr_to_bytecode_recursive(const struct lttng_event_expr *expr,
+		struct lttng_bytecode_alloc **bytecode,
+		struct lttng_bytecode_alloc **bytecode_reloc)
+{
+	int status;
+	enum lttng_event_expr_status event_expr_status;
+
+	switch (lttng_event_expr_get_type(expr)) {
+	case LTTNG_EVENT_EXPR_TYPE_EVENT_PAYLOAD_FIELD:
+	{
+		const char *name;
+
+		status = bytecode_push_get_payload_root(bytecode);
+		if (status) {
+			ERR("Failed to get payload root from bytecode");
+			goto end;
+		}
+
+		name = lttng_event_expr_event_payload_field_get_name(expr);
+		if (!name) {
+			ERR("Failed to get payload field name from event expression");
+			status = -1;
+			goto end;
+		}
+
+		status = bytecode_push_get_symbol(bytecode, bytecode_reloc, name);
+		if (status) {
+			ERR("Failed to push 'get symbol %s' in bytecode", name);
+			goto end;
+		}
+
+		break;
+	}
+	case LTTNG_EVENT_EXPR_TYPE_CHANNEL_CONTEXT_FIELD:
+	{
+		const char *name;
+
+		status = bytecode_push_get_context_root(bytecode);
+		if (status) {
+			ERR("Failed to get context root from bytecode");
+			goto end;
+		}
+
+		name = lttng_event_expr_channel_context_field_get_name(expr);
+		if (!name) {
+			ERR("Failed to get channel context field name from event expression");
+			status = -1;
+			goto end;
+		}
+
+		status = bytecode_push_get_symbol(bytecode, bytecode_reloc, name);
+		if (status) {
+			ERR("Failed to push 'get symbol %s' in bytecode", name);
+			goto end;
+		}
+
+		break;
+	}
+	case LTTNG_EVENT_EXPR_TYPE_APP_SPECIFIC_CONTEXT_FIELD:
+	{
+		int ret;
+		char *name = NULL;
+		const char *provider_name, *type_name;
+
+		status = bytecode_push_get_app_context_root(bytecode);
+		if (status) {
+			ERR("Failed to get application context root from bytecode");
+			goto end;
+		}
+
+		provider_name = lttng_event_expr_app_specific_context_field_get_provider_name(
+				expr);
+		if (!provider_name) {
+			ERR("Failed to get application context provider name from event expression");
+			status = -1;
+			goto end;
+		}
+
+		type_name = lttng_event_expr_app_specific_context_field_get_type_name(
+				expr);
+		if (!type_name) {
+			ERR("Failed to get application context type name from event expression");
+			status = -1;
+			goto end;
+		}
+
+		/*
+		 * Reconstitute the app context field name from its two parts.
+		 */
+		ret = asprintf(&name, "%s:%s", provider_name, type_name);
+		if (ret < 0) {
+			PERROR("Failed to format application specific context: provider_name = '%s', type_name = '%s'",
+					provider_name, type_name);
+			status = -1;
+			goto end;
+		}
+
+		status = bytecode_push_get_symbol(
+				bytecode, bytecode_reloc, name);
+		free(name);
+		if (status) {
+			ERR("Failed to push 'get symbol %s' in bytecode", name);
+			goto end;
+		}
+
+		break;
+	}
+	case LTTNG_EVENT_EXPR_TYPE_ARRAY_FIELD_ELEMENT:
+	{
+		unsigned int index;
+		const struct lttng_event_expr *parent;
+
+		parent = lttng_event_expr_array_field_element_get_parent_expr(
+				expr);
+		if (!parent) {
+			ERR("Failed to get parent expression from array event expression");
+			status = -1;
+			goto end;
+		}
+
+		status = event_expr_to_bytecode_recursive(
+				parent, bytecode, bytecode_reloc);
+		if (status) {
+			goto end;
+		}
+
+		event_expr_status = lttng_event_expr_array_field_element_get_index(
+				expr, &index);
+		if (event_expr_status != LTTNG_EVENT_EXPR_STATUS_OK) {
+			ERR("Failed to get array field element index from event expression");
+			status = -1;
+			goto end;
+		}
+
+		status = bytecode_push_get_index_u64(bytecode, index);
+		if (status) {
+			ERR("Failed to push 'get index %u' in bytecode", index);
+			goto end;
+		}
+
+		break;
+	}
+	default:
+		abort();
+	}
+
+	status = 0;
+end:
+	return status;
+}
+
+LTTNG_HIDDEN
+int lttng_event_expr_to_bytecode(const struct lttng_event_expr *expr,
+		struct lttng_bytecode **bytecode_out)
+{
+	int status;
+	struct return_op ret_insn;
+	struct lttng_bytecode_alloc *bytecode = NULL;
+	struct lttng_bytecode_alloc *bytecode_reloc = NULL;
+
+	status = bytecode_init(&bytecode);
+	if (status) {
+		ERR("Failed to initialize bytecode");
+		goto end;
+	}
+
+	status = bytecode_init(&bytecode_reloc);
+	if (status) {
+		ERR("Failed to initialize relocation bytecode");
+		goto end;
+	}
+
+	status = event_expr_to_bytecode_recursive(
+			expr, &bytecode, &bytecode_reloc);
+	if (status) {
+		/* Errors already logged. */
+		goto end;
+	}
+
+	ret_insn.op = BYTECODE_OP_RETURN;
+	bytecode_push(&bytecode, &ret_insn, 1, sizeof(ret_insn));
+
+	/* Append symbol table to bytecode. */
+	bytecode->b.reloc_table_offset = bytecode_get_len(&bytecode->b);
+	status = bytecode_push(&bytecode, bytecode_reloc->b.data, 1,
+			bytecode_get_len(&bytecode_reloc->b));
+	if (status) {
+		ERR("Failed to push symbol table to bytecode");
+		goto end;
+	}
+
+	/* Copy the `lttng_bytecode` out of the `lttng_bytecode_alloc`.  */
+	*bytecode_out = lttng_bytecode_copy(&bytecode->b);
+	if (!*bytecode_out) {
+		status = -1;
+		goto end;
+	}
+
+end:
+	if (bytecode) {
+		free(bytecode);
+	}
+
+	if (bytecode_reloc) {
+		free(bytecode_reloc);
+	}
+
+	return status;
+}