HACKING 4.6 KB

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  1. 0. The buildbot.
  2. http://tor-buildbot.freehaven.net:8010/
  3. 1. Coding conventions
  4. 1.0. Whitespace and C conformance
  5. Invoke "make check-spaces" from time to time, so it can tell you about
  6. deviations from our C whitespace style. Generally, we use:
  7. - Unix-style line endings
  8. - K&R-style indentation
  9. - No space before newlines
  10. - A blank line at the end of each file
  11. - Never more than one blank line in a row
  12. - Always spaces, never tabs
  13. - No more than 79-columns per line.
  14. - Two spaces per indent.
  15. - A space between control keywords and their corresponding paren
  16. "if (x)", "while (x)", and "switch (x)", never "if(x)", "while(x)", or
  17. "switch(x)".
  18. - A space between anything and an open brace.
  19. - No space between a function name and an opening paren. "puts(x)", not
  20. "puts (x)".
  21. - Function declarations at the start of the line.
  22. We try hard to build without warnings everywhere. In particular, if you're
  23. using gcc, you should invoke the configure script with the option
  24. "--enable-gcc-warnings". This will give a bunch of extra warning flags to
  25. the compiler, and help us find divergences from our preferred C style.
  26. 1.1. Details
  27. Use tor_malloc, tor_free, tor_strdup, and tor_gettimeofday instead of their
  28. generic equivalents. (They always succeed or exit.)
  29. You can get a full list of the compatibility functions that Tor provides
  30. by looking through src/common/util.h and src/common/compat.h.
  31. Use 'INLINE' instead of 'inline', so that we work properly on Windows.
  32. 1.2. Calling and naming conventions
  33. Whenever possible, functions should return -1 on error and 0 on success.
  34. For multi-word identifiers, use lowercase words combined with
  35. underscores. (e.g., "multi_word_identifier"). Use ALL_CAPS for macros and
  36. constants.
  37. Typenames should end with "_t".
  38. Function names should be prefixed with a module name or object name. (In
  39. general, code to manipulate an object should be a module with the same
  40. name as the object, so it's hard to tell which convention is used.)
  41. Functions that do things should have imperative-verb names
  42. (e.g. buffer_clear, buffer_resize); functions that return booleans should
  43. have predicate names (e.g. buffer_is_empty, buffer_needs_resizing).
  44. 1.3. What To Optimize
  45. Don't optimize anything if it's not in the critical path. Right now,
  46. the critical path seems to be AES, logging, and the network itself.
  47. Feel free to do your own profiling to determine otherwise.
  48. 1.4. Log conventions
  49. http://wiki.noreply.org/noreply/TheOnionRouter/TorFAQ#LogLevels
  50. No error or warning messages should be expected during normal OR or OP
  51. operation.
  52. If a library function is currently called such that failure always
  53. means ERR, then the library function should log WARN and let the caller
  54. log ERR.
  55. [XXX Proposed convention: every message of severity INFO or higher should
  56. either (A) be intelligible to end-users who don't know the Tor source; or
  57. (B) somehow inform the end-users that they aren't expected to understand
  58. the message (perhaps with a string like "internal error"). Option (A) is
  59. to be preferred to option (B). -NM]
  60. 1.5. Doxygen
  61. We use the 'doxygen' utility to generate documentation from our
  62. source code. Here's how to use it:
  63. 1. Begin every file that should be documented with
  64. /**
  65. * \file filename.c
  66. * \brief Short desccription of the file.
  67. **/
  68. (Doxygen will recognize any comment beginning with /** as special.)
  69. 2. Before any function, structure, #define, or variable you want to
  70. document, add a comment of the form:
  71. /** Describe the function's actions in imperative sentences.
  72. *
  73. * Use blank lines for paragraph breaks
  74. * - and
  75. * - hyphens
  76. * - for
  77. * - lists.
  78. *
  79. * Write <b>argument_names</b> in boldface.
  80. *
  81. * \code
  82. * place_example_code();
  83. * between_code_and_endcode_commands();
  84. * \endcode
  85. */
  86. 3. Make sure to escape the characters "<", ">", "\", "%" and "#" as "\<",
  87. "\>", "\\", "\%", and "\#".
  88. 4. To document structure members, you can use two forms:
  89. struct foo {
  90. /** You can put the comment before an element; */
  91. int a;
  92. int b; /**< Or use the less-than symbol to put the comment
  93. * after the element. */
  94. };
  95. 5. To generate documentation from the Tor source code, type:
  96. $ doxygen -g
  97. To generate a file called 'Doxyfile'. Edit that file and run
  98. 'doxygen' to generate the API documentation.
  99. 6. See the Doxygen manual for more information; this summary just
  100. scratches the surface.