v7.0.0

🚨 BREAKING CHANGES: Complete API redesign since v6.5.0
New type system, unified naming, and simplified build configuration. These notes cover only part of the changes.

🌟 Added

• Output Management System — unified destination control replacing callbacks
• Custom Log Levels — define your own schemes
• Static Configuration Header — central file for all build-time options
• Optional Warning on Disabled features
• Disabling the library fully using a compilation flag (e.g., for production releases)
• Extensions — modular, copy-paste-ready examples of extending functionality through the public API.
  • Syslog levels (RFC 5424)
  • Thread-safe locks for CMSIS-RTOS2, FreeRTOS, POSIX, ThreadX, Windows
  • Generic Logger Interface (integration layer for other libraries)
  • Microlog 6 compatibility layer for easy migration
• Quality Assurance — > 85 % line and > 90 % function test coverage

🪄 Changed

• Unified naming:
  • Functions → ulog_<feature>_<method>()
    • ulog_add_fp() → ulog_output_add_file()
    • ulog_set_lock() → ulog_lock_set_fn()
  • Types → snake_case
    • ulog_Event → ulog_event
    • ulog_LogFn → ulog_log_fn
• Build configuration moved in-source with ULOG_BUILD_* pattern

❌ Removed, 🐞 Fixed

• Removed emoji log levels 😭
• Removed log_* macro aliases — use ulog_* directly
• Numerous fixes and stability improvements

---

📄 Full details: CHANGELOG.md

v7.0.0-beta.2

🌟 Added

• ULOG_BUILD_DISABLED option to completely disable the library at compile time.
• Disabled feature test to ensure no code is included when disabled.

🪄 Changed

• ulog_lock_set_fn now returns ulog_status for error handling when locking fails.

v7.0.0-beta.1

🚨 BREAKING CHANGES: Complete API redesign from v6.5.0. This is a major architectural overhaul with new type system, function names, and build configuration.

The changelog below consolidates all changes from alpha versions leading up to this release.

🌟 Added

Core Features

• Output Management System: Unified system replacing callbacks for logging destinations

  • ulog_output_add() - Add custom callback outputs
  • ulog_output_add_file() - Add file outputs
  • ulog_output_remove() - Remove outputs dynamically
  • ulog_output_level_set() / ulog_output_level_set_all() - Per-output level control
  • ULOG_OUTPUT_STDOUT - Predefined output for stdout
  • Topics can be bound to specific outputs via ulog_topic_add(TOPIC, OUTPUT, LEVEL)

• Enhanced Type System: Modern C enum types for better type safety

  • ulog_level enum: ULOG_LEVEL_TRACE, ULOG_LEVEL_DEBUG, ULOG_LEVEL_INFO, ULOG_LEVEL_WARN, ULOG_LEVEL_ERROR, ULOG_LEVEL_FATAL
  • ulog_status enum: ULOG_STATUS_OK, ULOG_STATUS_ERROR, ULOG_STATUS_INVALID_ARGUMENT, ULOG_STATUS_NOT_FOUND, ULOG_STATUS_BUSY, ULOG_STATUS_DISABLED
  • ulog_topic_id type for topic identification
  • ulog_output type for output handles

• Custom Log Levels: Define your own level schemes

  • ulog_level_set_new_levels(ulog_level_descriptor) - Set custom levels
  • ulog_level_reset_levels() - Reset to defaults
  • Generic ULOG_LEVEL_0...7 available for custom schemes
  • New macros ulog_t(level, topic, ...) and ulog(level, ...) for dynamic level logging

• Static Configuration Header: Simplified build-time configuration

  • Enable with ULOG_BUILD_CONFIG_HEADER_ENABLED=1
  • Use ulog_config.h by default or customize with ULOG_BUILD_CONFIG_HEADER_NAME

Extensions

• Syslog Levels Extension (extensions/ulog_syslog.c/.h)

  • RFC 5424 style severities: DEBUG, INFO, NOTICE, WARN, ERR, CRIT, ALERT, EMERG

• Thread-Safe Lock Extensions for multiple platforms:

  • CMSIS-RTOS2, FreeRTOS, POSIX, ThreadX, and Windows

• Generic Logger Interface Extension

  • Easier migration from/to other logging libraries

• Comprehensive Documentation

  • Extensions included in releases
  • Documentation moved to extensions/README.md for better visibility

Resource Management

• ulog_topic_remove(TOPIC) - Remove topics dynamically
• ulog_cleanup() - Free all dynamic resources and reset state

Event Access API

• ulog_event_get_message() - Extract formatted message to buffer
• ulog_event_get_topic() - Get topic ID from event
• ulog_event_get_time() - Get timestamp from event
• ulog_event_get_file() / ulog_event_get_line() - Get source location
• ulog_event_get_level() - Get log level from event
• ulog_event_to_cstr() - Convert event to C string

Quality Assurance

• Unit tests with >85% line coverage and >90% function coverage

🪄 Changed

API Redesign

• Macro System: Dual macro system with improved naming

  • Primary: ulog_trace(), ulog_debug(), ulog_info(), ulog_warn(), ulog_error(), ulog_fatal()
  • Topic macros: ulog_t_*() (renamed from logt_*)
  • Basic log_* aliases removed - use ulog_* directly

• Function Renaming for consistency (selected examples):

  • ulog_get_level_string() → ulog_level_to_string()
  • ulog_set_level() → ulog_output_level_set_all()
  • ulog_set_quiet() → ulog_output_level_set(ULOG_OUTPUT_STDOUT, level)
  • ulog_add_callback() → ulog_output_add()
  • ulog_add_fp() → ulog_output_add_file()
  • ulog_set_lock() → ulog_lock_set_fn()
  • ulog_set_prefix_fn() → ulog_prefix_set_fn()
  • All topic functions now use ulog_topic_* prefix
  • All configuration functions now use *_config suffix

• Type Naming: Consistent snake_case convention

  • ulog_Event → ulog_event
  • ulog_LogFn → ulog_log_fn
  • ulog_LockFn → ulog_lock_fn
  • ulog_PrefixFn → ulog_prefix_fn

Build Configuration Revolution

All build configuration now uses unified ULOG_BUILD_* pattern:

Old	New
!ULOG_NO_COLOR	ULOG_BUILD_COLOR=1
ULOG_HAVE_TIME	ULOG_BUILD_TIME=1
ULOG_CUSTOM_PREFIX_SIZE	ULOG_BUILD_PREFIX_SIZE=N
ULOG_EXTRA_OUTPUTS	ULOG_BUILD_EXTRA_OUTPUTS=N
!ULOG_HIDE_FILE_STRING	ULOG_BUILD_SOURCE_LOCATION=1
ULOG_SHORT_LEVEL_STRINGS	ULOG_BUILD_LEVEL_SHORT=1
ULOG_TOPICS_NUM	ULOG_BUILD_TOPICS_MODE + ULOG_BUILD_TOPICS_STATIC_NUM
ULOG_RUNTIME_MODE	ULOG_BUILD_DYNAMIC_CONFIG=1

Topics Overhaul

• Level-Based Control: Topics now use log levels instead of simple enable/disable

  • ulog_topic_add() now takes a level parameter
  • Replaces previous binary enabled/disabled state

• Registration Required: All topics (static and dynamic) must use ulog_topic_add()

• Display Format: Changed from [Topic] LEVEL to LEVEL [Topic]

Enhanced Behavior

• Error Handling: Dynamic config functions and lock functions now return ulog_status
• Default Levels: Now aliases for generic ULOG_LEVEL_0...7
  • TRACE=0, DEBUG=1, INFO=2, WARN=3, ERROR=4, FATAL=5, Upper levels (6,7) unused by default
• Visual Improvements: FATAL level color changed from magenta to "red on white"
• Feature Names: Simplified naming (Custom Prefix → Prefix, Extra Outputs → Outputs, File String → Source Location, Runtime Mode → Dynamic Config)

Documentation & Examples

• Example application completely rewritten for v7.0 API
• Better inline documentation and demonstrations
• Syslog levels and dynamic level switching examples

❌ Removed

• Emoji Levels: ULOG_FEATURE_EMOJI_LEVELS / ULOG_USE_EMOJI completely removed
• Direct Event Access: Event struct removed from public API (use getter functions instead)
• Legacy Topic Functions: Removed due to level-based topic system
  • ulog_topic_enable() / ulog_topic_enable_all()
  • ulog_topic_disable() / ulog_topic_disable_all()
• Basic Macro Aliases: log_* aliases removed (use ulog_* directly)

🐞 Fixed

• Prefix callback execution (was called multiple times per log call)
• Potential buffer overflows in printing system
• Early exits on outputs and topics iteration after removal
• Memory allocation/deallocation for dynamic topics (including name strings)
• va_list handling issues in ulog_event_get_message() and ulog_event_to_cstr()
• Topic string processing and validation
• Buffer handling in print system
• Various bugs in test_time.cpp
• Consistency and formatting in feature documentation

v7.0.0-alpha.4

🌟 Added

• Add extensions to the release
• Add Static Configuration Header ulog_config.h feature to simplify configuration. Use ULOG_BUILD_CONFIG_HEADER_ENABLED=1 to enable it.
• Add ULOG_BUILD_CONFIG_HEADER_NAME to use a static configuration header instead of default ulog_config.h.

🪄 Changed

• Move extensions documentation from doc/extensions.md to extensions/README.md for better visibility
• Revamp topics handling from enable/disable to level-based
  • ulog_topic_add() now takes a level parameter instead of enabled/disabled state
• ULOG_BUILD_TOPICS_NUM is replaced with ULOG_BUILD_TOPICS_MODE and ULOG_BUILD_TOPICS_STATIC_NUM

❌ Removed

• Revamp topics handling from enable/disable to level-based
  • ulog_topic_enable() and ulog_topic_enable_all()
  • ulog_topic_disable() and ulog_topic_disable_all()

v7.0.0-alpha.3.ext

🌟 Add extensions package to the releases

v7.0.0-alpha.3

🌟 Added

• Custom log levels via ulog_level_set_new_levels(ulog_level_descriptor) / ulog_level_reset_levels()
• Replace default levels with generic ULOG_LEVEL_0...7 - for custom level schemes.
• New macros ulog_t(level, topic, ...) and ulog(level, ...) for dynamic level logging.
• ULOG_STATUS_DISABLED status code for disabled features.
• Extensions:
  • Syslog levels extension (extensions/ulog_syslog.c/.h) providing RFC 5424 style severities (DEBUG, INFO, NOTICE, WARN, ERR, CRIT, ALERT, EMERG)
  • Thread-safe lock extensions for CMSIS-RTOS2, FreeRTOS, POSIX, ThreadX, and Windows.
  • Generic logger interface extension for easier migration from/to other logging libraries.
  • New documentation page doc/extensions.md and README Extensions section.
• Unit tests. UT coverage: >85% lines, >90% functions

🪄 Changed

• ulog_prefix_set_fn now returns ulog_status for error handling.
• Default levels are now aliases for generic ULOG_LEVEL_0...7. TRACE = 0, DEBUG = 1, INFO = 2, WARN = 3, ERROR = 4, FATAL = 5. Upper levels (6,7) are unused by default.
• Color of FATAL level from "magenta" to "red on white" for better visibility.
• Example application updated to demonstrate syslog levels and dynamic level switching.
• ULOG_BUILD_LEVEL_STYLE replaced with ULOG_BUILD_LEVEL_SHORT (bool, 0/1) for static configuration of level style.

🐞 Fixed

• Minor consistency and formatting adjustments in feature documentation prior to extension introduction.
• Memory (de)allocation for dynamic topics, adding (de)allocation of name string.
• Potential problems with va_list in ulog_event_get_message() and ulog_event_to_cstr()

v7.0.0-alpha.2

🌟 Added

• Binding topic to a specific output via ulog_topic_add(TOPIC, OUTPUT, ENABLED)
• New status code: ULOG_STATUS_NOT_FOUND returned when a topic or output is not present (previously returned ULOG_STATUS_ERROR)
• ulog_topic_remove(TOPIC)
• ulog_cleanup() to free all dynamic resources and reset added entities (topics, outputs, etc.)

🪄 Changed

• BREAKING: Topics are now require ulog_topic_add() to be used. For both static and dynamic topics.
• BREAKING: Standardized macro alias naming conventions for consistency
  • Renamed topic aliases: logt_* → ulog_t_* (e.g., logt_info → ulog_t_info)
  • Removed basic aliases: log_* → use ulog_* directly (e.g., log_info → ulog_info)

🐞 Fixed

• Fix potential buffer overflows on printing
• Fix early exits on outputs and topics iteration after removal

v7.0.0-alpha.1

🚀 microlog v7.0.0-alpha.1 - Major Architecture Overhaul

⚠️ Breaking Changes Alert: This is a major version release with significant API changes. Please review the migration guide below before upgrading.

🌟 What's New

Output Management System (replaces callbacks)

• New ulog_output type for better output control
• Dynamic output management with ulog_output_add(), ulog_output_remove()
• Per-output level control with ulog_output_level_set()

Enhanced Type System

• Proper enum types: ulog_level, ulog_status, ulog_topic_id
• Type safety improvements throughout the API
• Better completion/refactoring support in IDEs

Event Getter Functions

Events are now private, you cannot access the fields directly!

Access private event data via getters:

const char* msg = ulog_event_get_message(event);
ulog_level level = ulog_event_get_level(event);
const char* file = ulog_event_get_file(event);
...

🔧 Major Changes

API Redesign

• Build Configuration: ULOG_FEATURE_* → ULOG_BUILD_*
• Log Levels: LOG_TRACE → ULOG_LEVEL_TRACE
• Function Names: Consistent ulog_<module>_<action> pattern
• Type Names: Consistent case, e.g. ulog_Event → ulog_event

Enhanced Features

• Better message alignment: Now shows as LEVEL [Topic] instead of [Topic] LEVEL
• Improved callback system with dynamic management
• Enhanced macro system with backward compatibility

🗑️ Removed Features

• Emoji Levels: Feature removed entirely
• Direct event access: Now use getter functions for type safety

🐞 Bug Fixes

• Fixed color detection logic
• Resolved prefix callback multiple execution
• Improved topic string processing
• Enhanced memory management

🔒 Security Improvements

• Enhanced type safety with proper enums
• Better input validation
• Improved memory management

📋 Migration Guide

TBD - after release

🎯 Testing

This is an alpha release - please test thoroughly in your development environment before considering for production use.

📚 Documentation

• Updated API documentation
• New example demonstrating v7 features

v6.5.1

• 🐞 Revert breaking change after accidentally introduced ULOG_HAVE_COLOR compilation flag

Docs: https://github.com/an-dr/microlog/blob/v6.5.1/README.md

v6.5.0

• 🌟 Add Runtime Configuration mode
  • With it enabled, you can compile a library with nearly all features enabled and control them from the code!