Log Viewer

Overview

The DVT Log Viewer is a powerful tool for simulation log analysis. It identifies structured entries such as UVM messages within the log and extracts attributes, like the timestamp, file, line, UVM component, message ID and text.

You can search and filter by entry attributes using an intuitive Query language. The log content is presented by default in a compact format, with a dedicated timeline. You can easily hyperlink to source code by file/line or UVM component, cross-link with the Waveform Viewer by timestamp and expand entries to drill down into details.

Right click on any file in the Explorer, and from the context menu choose Open With … ‣ Log Viewer, or browse to any location on disk from the File ‣ Open file… menu.

Tip

You can directly open zipped logs such as *.log.gz

When you open a log file, an Indexing process is started in the background.

The annotation ruler displays icons for message severity: warning, error and fatal

The timeline ruler presents message timestamps, highlighting changes so you can easily visualize groups of messages at the same timestamp. Double-click on a timestamp to reveal it in the current Waveform Viewer.

The viewer displays messages in a condensed format: filename, line, UVM component (report_object_name) and message ID as well as the first line of the actual message text. The filename link takes you to the source code line where the message was printed, for example the `uvm_info() call. The UVM component link takes you to the definition of the UVM report object.

You can expand the entries to inspect their structure, including the full message text.

The scrollbar allows quick navigation to the top and bottom of the log, as well as granular scrolling (page up/down, entry up/down).

Filtering and searching

You can type queries into the filter box at the top using a dedicated Query language. Press enter to apply the filter.

Ctrl+F brings up the search box at the bottom of the viewer. Type the query and use the arrows to navigate across matches. Press esc or click the close button to hide it.

Both filter and search input boxes provide content assist and input validation. Press Ctrl+Space to see available query keys and operators. Validation problems are clearly signaled, hover to get more information.

Message templates

Each template has a name, category and a pattern which is matched against the log content. Every pattern match creates a structured entry, mapping attribute keys to their matched value. The Log Viewer has built-in templates for standard UVM messages and popular compiler and simulator messages. To select which ones are applicable for the current log, from the ☰ menu choose Configure message templates:

Note

Templates are applied in the specified order - the first one matching a chunk of log file content consumes it. You can move them up and down in the list using the arrow buttons. In case of templates with overlapping patterns, keep the more specific templates ahead of generic ones.

From this dialog you can also define new templates, for example if using a custom uvm_report_server. Click the add button +, fill in the name and pattern, then click ✓ and OK.

Patterns are made up of plain text, which must match literally, and attributes. You can make an attribute optional by prefixing its name with a question mark, for example <?optional:text>. Attributes have the form <attribute_key:attribute_type> and match log content based on their type:

Attribute type	Example usage	Matches	Example match
file	<filename:file>	relative or absolute path	/path/to/uvm/src/uvm_pkg.sv
file_and_line	<fileline:file_and_line>	relative or absolute path followed by line number between brackets	../env/usb/usb_monitor.sv (1234)
line	<line_no:line>	positive number	3754
long	<timestamp:long>	integer numbers representable as standard ‘long’ format	12345678
report_object	<comp:report_object>	hierarchical path of a UVM component	uvm_test_top.env.usb_agents[0].usb_monitor
severity	<severity:severity>	an enumerated set of values mapped to warnings, errors and UVM severities	UVM_FATAL
text	<message:text>	any text including newlines numbers and symbols up to the next matching attribute	APB_READ: addr = ‘h810000, data = ‘h55
word	<timeunit:word>	single word, any combination of upper- and lower-case letters, digits and underscores	ps

You can use any identifier for attribute keys, however the following have a special meaning:

timestamp	matched values are shown on the timeline ruler
file, line, file_line_str, report_object	matched values are rendered as hyperlinks
severity	matched values are rendered as icons on the vertical ruler

Query language

Queries are used for filtering and searching the log entries. In the query you can reference any attribute key from the applicable patterns. A query can be as simple as a single match clause, for example:

message = “reset done”

matches entries where attribute key “message” has a value containing “reset done” text (case sensitive)

timestamp = 1234567

matches entries where attribute key “timestamp” has a value of exactly 1234567

You can combine multiple match clauses using boolean operators, for example:

message = “reset done” && timestamp > 1000

“reset done” messages after time 1000

You can combine clauses into complex queries using parentheses, for example:

message = “reset done” && (timestamp < 1000 || timestamp > 123456)

“reset done” messages outside a interval

message = “reset done” && (timestamp < 1000 || timestamp > 123456)

“reset done” messages outside a interval

report_object_name = “uart0.master_agent.driver” && (message_id = “RX_ITEM” || message_id = “TX_ITEM”)

all log entries from UART0 master driver with specific UVM message IDs

Note

The entry_structure built-in attribute is set to the name of the pattern, and can be used to hide all unmatched sections of the log using entry_structure != N/A

When used for filtering, the query can also include display modifiers:

Modifier	Example	Effect
hide	report_object_name = “uart0.master_agent.driver” && hide report_object_name	hide report_object_name in the collapsed entry as all entries will show the same matched value
sort_by	entry_structure = “Retry pattern” && sort_by:-nof_retries	show only user defined entry structures called “Retry pattern” and sort descending by custom attribute nof_retries in

Indexing

When you open a log file, it is processed in the background. Log entries are identified and a search/filter index is built. The index is saved in a folder called .dvt.<log_name>, side by side with the log file. If you reopen the log at a later time, the index is reused unless the log file changed.

Note

When the log is located in a read-only directory, the index is saved in a temporary location.

To save resources, indexing is lazy. For example, if you open a log to see just the first few configuration messages printed at the start of the test, only a few small chunks of the file are quickly indexed and content is immediately available. However, performing a narrow search might require the full index to be built. Once the index is built all subsequent operations are fast, regardless of the log size.

Tip

From the main menu you can choose to continue indexing in the background and return to a fully indexed log later.

Tip

Press the top right refresh button to bring in new content, for example when the current log is being actively generated.