X-Git-Url: http://git.efficios.com/?p=babeltrace.git;a=blobdiff_plain;f=src%2Fplugins%2Fctf%2Fcommon%2Fmetadata%2Fdecoder.c;h=342cba2fd82f7a1543d91adba5a8dca94c6a1296;hp=fdaf54bf7031be5b989ee01868e2adee7acc39ba;hb=0235b0db7de5bcacdb3650c92461f2ce5eb2143d;hpb=ef267d12284b855bc52ee429a5dc12da1d1e3b95

diff --git a/src/plugins/ctf/common/metadata/decoder.c b/src/plugins/ctf/common/metadata/decoder.c
index fdaf54bf..342cba2f 100644
--- a/src/plugins/ctf/common/metadata/decoder.c
+++ b/src/plugins/ctf/common/metadata/decoder.c
@@ -1,21 +1,13 @@
 /*
- * Copyright 2016-2017 - Philippe Proulx <pproulx@efficios.com>
+ * SPDX-License-Identifier: MIT
  *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
+ * Copyright 2016-2017 Philippe Proulx <pproulx@efficios.com>
  */
 
 #define BT_COMP_LOG_SELF_COMP (mdec->config.self_comp)
 #define BT_LOG_OUTPUT_LEVEL (mdec->config.log_level)
 #define BT_LOG_TAG "PLUGIN/CTF/META/DECODER"
-#include "plugins/comp-logging.h"
+#include "logging/comp-logging.h"
 
 #include <stdio.h>
 #include <stdbool.h>
@@ -23,7 +15,7 @@
 #include <stdlib.h>
 #include <inttypes.h>
 #include "common/assert.h"
-#include "compat/uuid.h"
+#include "common/uuid.h"
 #include "compat/memstream.h"
 #include <babeltrace2/babeltrace.h>
 #include <glib.h>
@@ -33,23 +25,24 @@
 #include "decoder.h"
 #include "scanner.h"
 #include "logging.h"
+#include "parser-wrap.h"
 
 #define TSDL_MAGIC	0x75d11d57
 
-extern
-int yydebug;
-
 struct ctf_metadata_decoder {
+	struct ctf_scanner *scanner;
+	GString *text;
 	struct ctf_visitor_generate_ir *visitor;
-	uint8_t uuid[16];
+	bt_uuid_t uuid;
 	bool is_uuid_set;
 	int bo;
 	struct ctf_metadata_decoder_config config;
+	struct meta_log_config log_cfg;
 };
 
 struct packet_header {
 	uint32_t magic;
-	uint8_t  uuid[16];
+	bt_uuid_t  uuid;
 	uint32_t checksum;
 	uint32_t content_size;
 	uint32_t packet_size;
@@ -61,26 +54,35 @@ struct packet_header {
 } __attribute__((__packed__));
 
 BT_HIDDEN
-bool ctf_metadata_decoder_is_packetized(FILE *fp, int *byte_order,
-		bt_logging_level log_level, bt_self_component *self_comp)
+int ctf_metadata_decoder_packetized_file_stream_to_buf(FILE *fp,
+		char **buf, int byte_order, bool *is_uuid_set,
+		uint8_t *uuid, bt_logging_level log_level,
+		bt_self_component *self_comp);
+
+BT_HIDDEN
+int ctf_metadata_decoder_is_packetized(FILE *fp, bool *is_packetized,
+		int *byte_order, bt_logging_level log_level,
+		bt_self_component *self_comp)
 {
 	uint32_t magic;
 	size_t len;
 	int ret = 0;
 
+	*is_packetized = false;
 	len = fread(&magic, sizeof(magic), 1, fp);
 	if (len != 1) {
 		BT_COMP_LOG_CUR_LVL(BT_LOG_INFO, log_level, self_comp,
 			"Cannot read first metadata packet header: assuming the stream is not packetized.");
+		ret = -1;
 		goto end;
 	}
 
 	if (byte_order) {
 		if (magic == TSDL_MAGIC) {
-			ret = 1;
+			*is_packetized = true;
 			*byte_order = BYTE_ORDER;
 		} else if (magic == GUINT32_SWAP_LE_BE(TSDL_MAGIC)) {
-			ret = 1;
+			*is_packetized = true;
 			*byte_order = BYTE_ORDER == BIG_ENDIAN ?
 				LITTLE_ENDIAN : BIG_ENDIAN;
 		}
@@ -92,272 +94,6 @@ end:
 	return ret;
 }
 
-static
-bool is_version_valid(unsigned int major, unsigned int minor)
-{
-	return major == 1 && minor == 8;
-}
-
-static
-int decode_packet(struct ctf_metadata_decoder *mdec, FILE *in_fp, FILE *out_fp,
-		int byte_order)
-{
-	struct packet_header header;
-	size_t readlen, writelen, toread;
-	uint8_t buf[512 + 1];	/* + 1 for debug-mode \0 */
-	int ret = 0;
-	const long offset = ftell(in_fp);
-
-	if (offset < 0) {
-		BT_COMP_LOGE_ERRNO("Failed to get current metadata file position",
-			".");
-		goto error;
-	}
-	BT_COMP_LOGD("Decoding metadata packet: mdec-addr=%p, offset=%ld",
-		mdec, offset);
-	readlen = fread(&header, sizeof(header), 1, in_fp);
-	if (feof(in_fp) != 0) {
-		BT_COMP_LOGI("Reached end of file: offset=%ld", ftell(in_fp));
-		goto end;
-	}
-	if (readlen < 1) {
-		BT_COMP_LOGE("Cannot decode metadata packet: offset=%ld", offset);
-		goto error;
-	}
-
-	if (byte_order != BYTE_ORDER) {
-		header.magic = GUINT32_SWAP_LE_BE(header.magic);
-		header.checksum = GUINT32_SWAP_LE_BE(header.checksum);
-		header.content_size = GUINT32_SWAP_LE_BE(header.content_size);
-		header.packet_size = GUINT32_SWAP_LE_BE(header.packet_size);
-	}
-
-	if (header.compression_scheme) {
-		BT_COMP_LOGE("Metadata packet compression is not supported as of this version: "
-			"compression-scheme=%u, offset=%ld",
-			(unsigned int) header.compression_scheme, offset);
-		goto error;
-	}
-
-	if (header.encryption_scheme) {
-		BT_COMP_LOGE("Metadata packet encryption is not supported as of this version: "
-			"encryption-scheme=%u, offset=%ld",
-			(unsigned int) header.encryption_scheme, offset);
-		goto error;
-	}
-
-	if (header.checksum || header.checksum_scheme) {
-		BT_COMP_LOGE("Metadata packet checksum verification is not supported as of this version: "
-			"checksum-scheme=%u, checksum=%x, offset=%ld",
-			(unsigned int) header.checksum_scheme, header.checksum,
-			offset);
-		goto error;
-	}
-
-	if (!is_version_valid(header.major, header.minor)) {
-		BT_COMP_LOGE("Invalid metadata packet version: "
-			"version=%u.%u, offset=%ld",
-			header.major, header.minor, offset);
-		goto error;
-	}
-
-	/* Set expected trace UUID if not set; otherwise validate it */
-	if (mdec) {
-		if (!mdec->is_uuid_set) {
-			memcpy(mdec->uuid, header.uuid, sizeof(header.uuid));
-			mdec->is_uuid_set = true;
-		} else if (bt_uuid_compare(header.uuid, mdec->uuid)) {
-			BT_COMP_LOGE("Metadata UUID mismatch between packets of the same stream: "
-				"packet-uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\", "
-				"expected-uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\", "
-				"offset=%ld",
-				(unsigned int) header.uuid[0],
-				(unsigned int) header.uuid[1],
-				(unsigned int) header.uuid[2],
-				(unsigned int) header.uuid[3],
-				(unsigned int) header.uuid[4],
-				(unsigned int) header.uuid[5],
-				(unsigned int) header.uuid[6],
-				(unsigned int) header.uuid[7],
-				(unsigned int) header.uuid[8],
-				(unsigned int) header.uuid[9],
-				(unsigned int) header.uuid[10],
-				(unsigned int) header.uuid[11],
-				(unsigned int) header.uuid[12],
-				(unsigned int) header.uuid[13],
-				(unsigned int) header.uuid[14],
-				(unsigned int) header.uuid[15],
-				(unsigned int) mdec->uuid[0],
-				(unsigned int) mdec->uuid[1],
-				(unsigned int) mdec->uuid[2],
-				(unsigned int) mdec->uuid[3],
-				(unsigned int) mdec->uuid[4],
-				(unsigned int) mdec->uuid[5],
-				(unsigned int) mdec->uuid[6],
-				(unsigned int) mdec->uuid[7],
-				(unsigned int) mdec->uuid[8],
-				(unsigned int) mdec->uuid[9],
-				(unsigned int) mdec->uuid[10],
-				(unsigned int) mdec->uuid[11],
-				(unsigned int) mdec->uuid[12],
-				(unsigned int) mdec->uuid[13],
-				(unsigned int) mdec->uuid[14],
-				(unsigned int) mdec->uuid[15],
-				offset);
-			goto error;
-		}
-	}
-
-	if ((header.content_size / CHAR_BIT) < sizeof(header)) {
-		BT_COMP_LOGE("Bad metadata packet content size: content-size=%u, "
-			"offset=%ld", header.content_size, offset);
-		goto error;
-	}
-
-	toread = header.content_size / CHAR_BIT - sizeof(header);
-
-	for (;;) {
-		size_t loop_read;
-
-		loop_read = MIN(sizeof(buf) - 1, toread);
-		readlen = fread(buf, sizeof(uint8_t), loop_read, in_fp);
-		if (ferror(in_fp)) {
-			BT_COMP_LOGE("Cannot read metadata packet buffer: "
-				"offset=%ld, read-size=%zu",
-				ftell(in_fp), loop_read);
-			goto error;
-		}
-		if (readlen > loop_read) {
-			BT_COMP_LOGE("fread returned more byte than expected: "
-				"read-size-asked=%zu, read-size-returned=%zu",
-				loop_read, readlen);
-			goto error;
-		}
-
-		writelen = fwrite(buf, sizeof(uint8_t), readlen, out_fp);
-		if (writelen < readlen || ferror(out_fp)) {
-			BT_COMP_LOGE("Cannot write decoded metadata text to buffer: "
-				"read-offset=%ld, write-size=%zu",
-				ftell(in_fp), readlen);
-			goto error;
-		}
-
-		toread -= readlen;
-		if (toread == 0) {
-			int fseek_ret;
-
-			/* Read leftover padding */
-			toread = (header.packet_size - header.content_size) /
-				CHAR_BIT;
-			fseek_ret = fseek(in_fp, toread, SEEK_CUR);
-			if (fseek_ret < 0) {
-				BT_COMP_LOGW_STR("Missing padding at the end of the metadata stream.");
-			}
-			break;
-		}
-	}
-
-	goto end;
-
-error:
-	ret = -1;
-
-end:
-	return ret;
-}
-
-static
-int ctf_metadata_decoder_packetized_file_stream_to_buf_with_mdec(
-		struct ctf_metadata_decoder *mdec, FILE *fp,
-		char **buf, int byte_order, bt_logging_level log_level,
-		bt_self_component *self_comp)
-{
-	FILE *out_fp;
-	size_t size;
-	int ret = 0;
-	int tret;
-	size_t packet_index = 0;
-
-	out_fp = bt_open_memstream(buf, &size);
-	if (out_fp == NULL) {
-		BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
-			"Cannot open memory stream: %s: mdec-addr=%p",
-			strerror(errno), mdec);
-		goto error;
-	}
-
-	for (;;) {
-		if (feof(fp) != 0) {
-			break;
-		}
-
-		tret = decode_packet(mdec, fp, out_fp, byte_order);
-		if (tret) {
-			BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
-				"Cannot decode packet: index=%zu, mdec-addr=%p",
-				packet_index, mdec);
-			goto error;
-		}
-
-		packet_index++;
-	}
-
-	/* Make sure the whole string ends with a null character */
-	tret = fputc('\0', out_fp);
-	if (tret == EOF) {
-		BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
-			"Cannot append '\\0' to the decoded metadata buffer: "
-			"mdec-addr=%p", mdec);
-		goto error;
-	}
-
-	/* Close stream, which also flushes the buffer */
-	ret = bt_close_memstream(buf, &size, out_fp);
-	/*
-	 * See fclose(3). Further access to out_fp after both success
-	 * and error, even through another bt_close_memstream(), results
-	 * in undefined behavior. Nullify out_fp to ensure we don't
-	 * fclose it twice on error.
-	 */
-	out_fp = NULL;
-	if (ret < 0) {
-		BT_COMP_LOG_ERRNO_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
-			"Cannot close memory stream", ": mdec-addr=%p", mdec);
-		goto error;
-	}
-
-	goto end;
-
-error:
-	ret = -1;
-
-	if (out_fp) {
-		if (bt_close_memstream(buf, &size, out_fp)) {
-			BT_COMP_LOG_ERRNO_CUR_LVL(BT_LOG_ERROR, log_level,
-				self_comp, "Cannot close memory stream",
-				": mdec-addr=%p", mdec);
-		}
-	}
-
-	if (*buf) {
-		free(*buf);
-		*buf = NULL;
-	}
-
-end:
-	return ret;
-}
-
-BT_HIDDEN
-int ctf_metadata_decoder_packetized_file_stream_to_buf(
-		FILE *fp, char **buf, int byte_order,
-		bt_logging_level log_level,
-		bt_self_component *self_comp)
-{
-	return ctf_metadata_decoder_packetized_file_stream_to_buf_with_mdec(
-		NULL, fp, buf, byte_order, log_level, self_comp);
-}
-
 BT_HIDDEN
 struct ctf_metadata_decoder *ctf_metadata_decoder_create(
 		const struct ctf_metadata_decoder_config *config)
@@ -379,14 +115,29 @@ struct ctf_metadata_decoder *ctf_metadata_decoder_create(
 		goto end;
 	}
 
+	mdec->log_cfg.log_level = config->log_level;
+	mdec->log_cfg.self_comp = config->self_comp;
+	mdec->scanner = ctf_scanner_alloc();
+	if (!mdec->scanner) {
+		BT_COMP_LOGE("Cannot allocate a metadata lexical scanner: "
+			"mdec-addr=%p", mdec);
+		goto error;
+	}
+
+	mdec->text = g_string_new(NULL);
+	if (!mdec->text) {
+		BT_COMP_LOGE("Failed to allocate one GString: "
+			"mdec-addr=%p", mdec);
+		goto error;
+	}
+
+	mdec->bo = -1;
 	mdec->config = *config;
 	mdec->visitor = ctf_visitor_generate_ir_create(config);
 	if (!mdec->visitor) {
 		BT_COMP_LOGE("Failed to create a CTF IR metadata AST visitor: "
 			"mdec-addr=%p", mdec);
-		ctf_metadata_decoder_destroy(mdec);
-		mdec = NULL;
-		goto end;
+		goto error;
 	}
 
 	BT_COMP_LOGD("Creating CTF metadata decoder: "
@@ -394,6 +145,11 @@ struct ctf_metadata_decoder *ctf_metadata_decoder_create(
 		"clock-class-offset-ns=%" PRId64 ", addr=%p",
 		config->clock_class_offset_s, config->clock_class_offset_ns,
 		mdec);
+	goto end;
+
+error:
+	ctf_metadata_decoder_destroy(mdec);
+	mdec = NULL;
 
 end:
 	return mdec;
@@ -406,32 +162,44 @@ void ctf_metadata_decoder_destroy(struct ctf_metadata_decoder *mdec)
 		return;
 	}
 
+	if (mdec->scanner) {
+		ctf_scanner_free(mdec->scanner);
+	}
+
+	if (mdec->text) {
+		g_string_free(mdec->text, TRUE);
+	}
+
 	BT_COMP_LOGD("Destroying CTF metadata decoder: addr=%p", mdec);
 	ctf_visitor_generate_ir_destroy(mdec->visitor);
 	g_free(mdec);
 }
 
 BT_HIDDEN
-enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
+enum ctf_metadata_decoder_status ctf_metadata_decoder_append_content(
 		struct ctf_metadata_decoder *mdec, FILE *fp)
 {
 	enum ctf_metadata_decoder_status status =
 		CTF_METADATA_DECODER_STATUS_OK;
 	int ret;
-	struct ctf_scanner *scanner = NULL;
 	char *buf = NULL;
 	bool close_fp = false;
-	struct meta_log_config log_cfg;
+	long start_pos = -1;
+	bool is_packetized;
 
 	BT_ASSERT(mdec);
-	log_cfg.log_level = mdec->config.log_level;
-	log_cfg.self_comp = mdec->config.self_comp;
+	ret = ctf_metadata_decoder_is_packetized(fp, &is_packetized, &mdec->bo,
+			mdec->config.log_level, mdec->config.self_comp);
+	if (ret) {
+		status = CTF_METADATA_DECODER_STATUS_ERROR;
+		goto end;
+	}
 
-	if (ctf_metadata_decoder_is_packetized(fp, &mdec->bo,
-			mdec->config.log_level, mdec->config.self_comp)) {
+	if (is_packetized) {
 		BT_COMP_LOGI("Metadata stream is packetized: mdec-addr=%p", mdec);
-		ret = ctf_metadata_decoder_packetized_file_stream_to_buf_with_mdec(
-			mdec, fp, &buf, mdec->bo, mdec->config.log_level,
+		ret = ctf_metadata_decoder_packetized_file_stream_to_buf(fp,
+			&buf, mdec->bo, &mdec->is_uuid_set,
+			mdec->uuid, mdec->config.log_level,
 			mdec->config.self_comp);
 		if (ret) {
 			BT_COMP_LOGE("Cannot decode packetized metadata packets to metadata text: "
@@ -476,7 +244,8 @@ enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
 
 		BT_COMP_LOGI("Found metadata stream version in signature: version=%u.%u", major, minor);
 
-		if (!is_version_valid(major, minor)) {
+		if (!ctf_metadata_decoder_is_packet_version_valid(major,
+				minor)) {
 			BT_COMP_LOGE("Invalid metadata version found in plain text signature: "
 				"version=%u.%u, mdec-addr=%p", major, minor,
 				mdec);
@@ -492,21 +261,21 @@ enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
 		}
 	}
 
+#if YYDEBUG
 	if (BT_LOG_ON_TRACE) {
 		yydebug = 1;
 	}
+#endif
 
-	/* Allocate a scanner and append the metadata text content */
-	scanner = ctf_scanner_alloc();
-	if (!scanner) {
-		BT_COMP_LOGE("Cannot allocate a metadata lexical scanner: "
-			"mdec-addr=%p", mdec);
-		status = CTF_METADATA_DECODER_STATUS_ERROR;
-		goto end;
+	/* Save the file's position: we'll seek back to append the plain text */
+	BT_ASSERT(fp);
+
+	if (mdec->config.keep_plain_text) {
+		start_pos = ftell(fp);
 	}
 
-	BT_ASSERT(fp);
-	ret = ctf_scanner_append_ast(scanner, fp);
+	/* Append the metadata text content */
+	ret = ctf_scanner_append_ast(mdec->scanner, fp);
 	if (ret) {
 		BT_COMP_LOGE("Cannot create the metadata AST out of the metadata text: "
 			"mdec-addr=%p", mdec);
@@ -514,7 +283,28 @@ enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
 		goto end;
 	}
 
-	ret = ctf_visitor_semantic_check(0, &scanner->ast->root, &log_cfg);
+	/* We know it's complete: append plain text */
+	if (mdec->config.keep_plain_text) {
+		BT_ASSERT(start_pos != -1);
+		ret = fseek(fp, start_pos, SEEK_SET);
+		if (ret) {
+			BT_COMP_LOGE("Failed to seek file: ret=%d, mdec-addr=%p",
+				ret, mdec);
+			status = CTF_METADATA_DECODER_STATUS_ERROR;
+			goto end;
+		}
+
+		ret = bt_common_append_file_content_to_g_string(mdec->text, fp);
+		if (ret) {
+			BT_COMP_LOGE("Failed to append to current plain text: "
+				"ret=%d, mdec-addr=%p", ret, mdec);
+			status = CTF_METADATA_DECODER_STATUS_ERROR;
+			goto end;
+		}
+	}
+
+	ret = ctf_visitor_semantic_check(0, &mdec->scanner->ast->root,
+		&mdec->log_cfg);
 	if (ret) {
 		BT_COMP_LOGE("Validation of the metadata semantics failed: "
 			"mdec-addr=%p", mdec);
@@ -522,30 +312,30 @@ enum ctf_metadata_decoder_status ctf_metadata_decoder_decode(
 		goto end;
 	}
 
-	ret = ctf_visitor_generate_ir_visit_node(mdec->visitor,
-		&scanner->ast->root);
-	switch (ret) {
-	case 0:
-		/* Success */
-		break;
-	case -EINCOMPLETE:
-		BT_COMP_LOGD("While visiting metadata AST: incomplete data: "
-			"mdec-addr=%p", mdec);
-		status = CTF_METADATA_DECODER_STATUS_INCOMPLETE;
-		goto end;
-	default:
-		BT_COMP_LOGE("Failed to visit AST node to create CTF IR objects: "
-			"mdec-addr=%p, ret=%d", mdec, ret);
-		status = CTF_METADATA_DECODER_STATUS_IR_VISITOR_ERROR;
-		goto end;
+	if (mdec->config.create_trace_class) {
+		ret = ctf_visitor_generate_ir_visit_node(mdec->visitor,
+			&mdec->scanner->ast->root);
+		switch (ret) {
+		case 0:
+			/* Success */
+			break;
+		case -EINCOMPLETE:
+			BT_COMP_LOGD("While visiting metadata AST: incomplete data: "
+				"mdec-addr=%p", mdec);
+			status = CTF_METADATA_DECODER_STATUS_INCOMPLETE;
+			goto end;
+		default:
+			BT_COMP_LOGE("Failed to visit AST node to create CTF IR objects: "
+				"mdec-addr=%p, ret=%d", mdec, ret);
+			status = CTF_METADATA_DECODER_STATUS_IR_VISITOR_ERROR;
+			goto end;
+		}
 	}
 
 end:
-	if (scanner) {
-		ctf_scanner_free(scanner);
-	}
-
+#if YYDEBUG
 	yydebug = 0;
+#endif
 
 	if (fp && close_fp) {
 		if (fclose(fp)) {
@@ -554,9 +344,7 @@ end:
 		}
 	}
 
-	if (buf) {
-		free(buf);
-	}
+	free(buf);
 
 	return status;
 }
@@ -565,6 +353,8 @@ BT_HIDDEN
 bt_trace_class *ctf_metadata_decoder_get_ir_trace_class(
 		struct ctf_metadata_decoder *mdec)
 {
+	BT_ASSERT_DBG(mdec);
+	BT_ASSERT_DBG(mdec->config.create_trace_class);
 	return ctf_visitor_generate_ir_get_ir_trace_class(mdec->visitor);
 }
 
@@ -572,5 +362,118 @@ BT_HIDDEN
 struct ctf_trace_class *ctf_metadata_decoder_borrow_ctf_trace_class(
 		struct ctf_metadata_decoder *mdec)
 {
+	BT_ASSERT_DBG(mdec);
+	BT_ASSERT_DBG(mdec->config.create_trace_class);
 	return ctf_visitor_generate_ir_borrow_ctf_trace_class(mdec->visitor);
 }
+
+BT_HIDDEN
+const char *ctf_metadata_decoder_get_text(struct ctf_metadata_decoder *mdec)
+{
+	BT_ASSERT_DBG(mdec);
+	BT_ASSERT_DBG(mdec->config.keep_plain_text);
+	return mdec->text->str;
+}
+
+BT_HIDDEN
+int ctf_metadata_decoder_get_byte_order(struct ctf_metadata_decoder *mdec)
+{
+	BT_ASSERT_DBG(mdec);
+	return mdec->bo;
+}
+
+BT_HIDDEN
+int ctf_metadata_decoder_get_uuid(struct ctf_metadata_decoder *mdec,
+		bt_uuid_t uuid)
+{
+	int ret = 0;
+
+	BT_ASSERT_DBG(mdec);
+
+	if (!mdec->is_uuid_set) {
+		ret = -1;
+		goto end;
+	}
+
+	bt_uuid_copy(uuid, mdec->uuid);
+
+end:
+	return ret;
+}
+
+static
+enum ctf_metadata_decoder_status find_uuid_in_trace_decl(
+		struct ctf_metadata_decoder *mdec, struct ctf_node *trace_node,
+		bt_uuid_t uuid)
+{
+	enum ctf_metadata_decoder_status status =
+		CTF_METADATA_DECODER_STATUS_OK;
+	struct ctf_node *entry_node;
+	struct bt_list_head *decl_list = &trace_node->u.trace.declaration_list;
+	char *left = NULL;
+
+	bt_list_for_each_entry(entry_node, decl_list, siblings) {
+		if (entry_node->type == NODE_CTF_EXPRESSION) {
+			int ret;
+
+			left = ctf_ast_concatenate_unary_strings(
+				&entry_node->u.ctf_expression.left);
+			if (!left) {
+				BT_COMP_LOGE("Cannot concatenate unary strings.");
+				status = CTF_METADATA_DECODER_STATUS_ERROR;
+				goto end;
+			}
+
+			if (strcmp(left, "uuid") == 0) {
+				ret = ctf_ast_get_unary_uuid(
+					&entry_node->u.ctf_expression.right,
+					uuid, mdec->config.log_level,
+					mdec->config.self_comp);
+				if (ret) {
+					BT_COMP_LOGE("Invalid trace's `uuid` attribute.");
+					status = CTF_METADATA_DECODER_STATUS_ERROR;
+					goto end;
+				}
+
+				goto end;
+			}
+
+			g_free(left);
+			left = NULL;
+		}
+	}
+
+	status = CTF_METADATA_DECODER_STATUS_NONE;
+
+end:
+	g_free(left);
+	return status;
+}
+
+BT_HIDDEN
+enum ctf_metadata_decoder_status ctf_metadata_decoder_get_trace_class_uuid(
+		struct ctf_metadata_decoder *mdec, bt_uuid_t uuid)
+{
+	enum ctf_metadata_decoder_status status =
+		CTF_METADATA_DECODER_STATUS_INCOMPLETE;
+	struct ctf_node *root_node = &mdec->scanner->ast->root;
+	struct ctf_node *trace_node;
+
+	if (!root_node) {
+		status = CTF_METADATA_DECODER_STATUS_INCOMPLETE;
+		goto end;
+	}
+
+	trace_node =
+		bt_list_entry(root_node->u.root.trace.next,
+			struct ctf_node, siblings);
+	if (!trace_node) {
+		status = CTF_METADATA_DECODER_STATUS_INCOMPLETE;
+		goto end;
+	}
+
+	status = find_uuid_in_trace_decl(mdec, trace_node, uuid);
+
+end:
+	return status;
+}