pw_trace: Add pw_trace:null as default backend

This module is added to act as the default backend for pw_trace where
trace is disabled. With this module, applications would not be required
to set a backend. This backend is implemented with empty functions and
handles unused variables as well.

Test: presubmit involves tests. But an application without backend is
set.
Bug: b/202193001

Change-Id: I676d49ffedf64e5ce493f188349b5a4d8ba17153
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/68141
Reviewed-by: Wyatt Hepler <hepler@google.com>
Reviewed-by: Rob Oliver <rgoliver@google.com>
Commit-Queue: Yuanyao Zhong <yyzhong@google.com>
9 files changed
tree: b3f40d65e9b7b323cc39243effe30a9ca176e42d
  1. build_overrides/
  2. docker/
  3. docs/
  4. pw_allocator/
  5. pw_analog/
  6. pw_android_toolchain/
  7. pw_arduino_build/
  8. pw_assert/
  9. pw_assert_basic/
  10. pw_assert_log/
  11. pw_base64/
  12. pw_bloat/
  13. pw_blob_store/
  14. pw_bluetooth_hci/
  15. pw_boot/
  16. pw_boot_cortex_m/
  17. pw_build/
  18. pw_build_info/
  19. pw_build_mcuxpresso/
  20. pw_bytes/
  21. pw_checksum/
  22. pw_chrono/
  23. pw_chrono_embos/
  24. pw_chrono_freertos/
  25. pw_chrono_stl/
  26. pw_chrono_threadx/
  27. pw_cli/
  28. pw_console/
  29. pw_containers/
  30. pw_cpu_exception/
  31. pw_cpu_exception_cortex_m/
  32. pw_crypto/
  33. pw_docgen/
  34. pw_doctor/
  35. pw_env_setup/
  36. pw_file/
  37. pw_function/
  38. pw_fuzzer/
  39. pw_hdlc/
  40. pw_hex_dump/
  41. pw_i2c/
  42. pw_interrupt/
  43. pw_interrupt_cortex_m/
  44. pw_kvs/
  45. pw_libc/
  46. pw_log/
  47. pw_log_basic/
  48. pw_log_null/
  49. pw_log_rpc/
  50. pw_log_tokenized/
  51. pw_malloc/
  52. pw_malloc_freelist/
  53. pw_metric/
  54. pw_minimal_cpp_stdlib/
  55. pw_module/
  56. pw_multisink/
  57. pw_package/
  58. pw_persistent_ram/
  59. pw_polyfill/
  60. pw_preprocessor/
  61. pw_presubmit/
  62. pw_protobuf/
  63. pw_protobuf_compiler/
  64. pw_random/
  65. pw_result/
  66. pw_ring_buffer/
  67. pw_router/
  68. pw_rpc/
  69. pw_snapshot/
  70. pw_software_update/
  71. pw_span/
  72. pw_status/
  73. pw_stm32cube_build/
  74. pw_stream/
  75. pw_string/
  76. pw_symbolizer/
  77. pw_sync/
  78. pw_sync_baremetal/
  79. pw_sync_embos/
  80. pw_sync_freertos/
  81. pw_sync_stl/
  82. pw_sync_threadx/
  83. pw_sys_io/
  84. pw_sys_io_arduino/
  85. pw_sys_io_baremetal_lm3s6965evb/
  86. pw_sys_io_baremetal_stm32f429/
  87. pw_sys_io_mcuxpresso/
  88. pw_sys_io_stdio/
  89. pw_target_runner/
  90. pw_thread/
  91. pw_thread_embos/
  92. pw_thread_freertos/
  93. pw_thread_stl/
  94. pw_thread_threadx/
  95. pw_tls_client/
  96. pw_tls_client_boringssl/
  97. pw_tls_client_mbedtls/
  98. pw_tokenizer/
  99. pw_tool/
  100. pw_toolchain/
  101. pw_trace/
  102. pw_trace_tokenized/
  103. pw_transfer/
  104. pw_unit_test/
  105. pw_varint/
  106. pw_watch/
  107. pw_web_ui/
  108. pw_work_queue/
  109. targets/
  110. third_party/
  111. .bazelignore
  112. .bazelrc
  113. .clang-format
  114. .clang-tidy
  115. .eslintrc.json
  116. .gitattributes
  117. .gitignore
  118. .gn
  119. .prettierrc.js
  120. .pylintrc
  121. activate.bat
  122. AUTHORS
  123. bootstrap.bat
  124. bootstrap.sh
  125. BUILD.bazel
  126. BUILD.gn
  127. BUILDCONFIG.gn
  128. CMakeLists.txt
  129. LICENSE
  130. modules.gni
  131. OWNERS
  132. package.json
  133. PW_PLUGINS
  134. README.md
  135. tsconfig.json
  136. WORKSPACE
  137. yarn.lock
README.md

Pigweed

Pigweed is an open source collection of embedded-targeted libraries–or as we like to call them, modules. These modules are building blocks and infrastructure that enable faster and more reliable development on small-footprint MMU-less 32-bit microcontrollers like the STMicroelectronics STM32L452 or the Nordic nRF52832.

For more information please see our website: https://pigweed.dev/

Links