1. Building Dinit
  2. =-=-=-=-=-=-=-
  3. Building Dinit should be a straight-forward process. It requires GNU make and a C++11 compiler
  4. (GCC version 4.9 and later, or Clang ~5.0 and later, should be fine)
  5. On the directly supported operating systems - Linux, OpenBSD, FreeBSD and Darwin (macOS) - a
  6. suitable build configuration is provided and will be used automatically if no manual configuration
  7. is supplied - skip directly to running "make" (more details below) if you are on one of these
  8. systems and are happy to use the default configuration.
  9. For other systems, or to fine tune or correct the configuration, create and edit the
  10. "mconfig" file (start by copying one for a particular OS from the "configs" directory) to choose
  11. appropriate values for the configuration variables defined within. In particular:
  12. CXX : should be set to the name of the C++ compiler (and link driver)
  13. CXXOPTS : are options passed to the compiler during compilation (see note for GCC below)
  14. LDFLAGS : are any extra flags required for linking; should not normally be needed
  15. (FreeBSD requires -lrt).
  16. Note that the "eg++" or "clang++" package must be installed on OpenBSD as the default "g++"
  17. compiler is too old. Clang is part of the base system in recent releases.
  18. Then, from the top-level directory, run "make" (or "gmake" if the system make is not GNU make,
  19. such as on most BSD systems):
  20. make
  21. If everything goes smoothly this will build dinit, dinitctl, and optionally the shutdown
  22. utility. Use "make install" to install; you can specify an alternate installation by
  23. setting the "DESTDIR" variable, eg "make DESTDIR=/tmp/temporary-install-path install".
  24. Recommended Compiler options
  25. =-=-=-=-=-=-=-=-=-=-=-=-=-=-
  26. Dinit should generally build fine with no additional options, other than:
  27. -std=c++11 : may be required to select correct C++ standard.
  28. -D_GLIBCXX_USE_CXX11_ABI=1 : see "Special note for GCC/Libstdc++", below. Not needed for
  29. most modern systems.
  30. Recommended options, supported by at least GCC and Clang, are:
  31. -Os : optimise for size
  32. -fno-rtti : disable RTTI (run-time type information), it is not required by Dinit.
  33. However, on some platforms such as Mac OS (and historically FreeBSD, IIRC), this
  34. prevents exceptions working correctly.
  35. -fno-plt : enables better code generation for non-static builds, but may cause unit test
  36. failures on some older versions of FreeBSD (11.2-RELEASE-p4 with clang++ 6.0.0).
  37. -flto : perform link-time optimisation (option required at compile and link).
  38. Consult compiler documentation for further information on the above options.
  39. Other configuration variables
  40. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=
  41. There are a number of other variables you can set in the mconfig file which affect the build:
  42. SBINDIR=...
  43. Where the "/sbin" directory is. Executables will be installed here.
  44. MANDIR=...
  45. Where the "man" directory is. Man pages will be installed here.
  47. Default full path to the control socket, for when Dinit runs as system service manager.
  48. BUILD_SHUTDOWN=yes|no
  49. Whether to build the "shutdown" (and "halt" etc) utilities. These are only useful
  50. if dinit is the system init (i.e. the PID 1 process). You probably don't want this
  51. unless building for Linux.
  53. Name prefix for "shutdown", "halt" and "reboot" commands (if they are built). This affects
  54. both the output, and what command dinit will execute as part of system shutdown.
  55. If you want to install Dinit alongside another init system with its own shutdown/halt/reboot
  56. commands, set this (for eg. to "dinit-").
  57. USE_UTMPX=1|0
  58. Whether to build support for manipulating the utmp/utmpx database via the related POSIX
  59. functions. This may be required (along with appropriate service configuration) for utilities
  60. like "who" to work correctly (the service configuration items "inittab-id" and "inittab-line"
  61. have no effect if this is disabled). If not set to any value, support is enabled for certain
  62. systems automatically and disabled for all others.
  64. Any options to enable run-time sanitizers or additional safety checks. This will be used
  65. only when building tests. It can safely be left blank.
  66. Running test suite
  67. =-=-=-=-=-=-=-=-=-
  68. Build the "check" target in order to run the test suite:
  69. make check
  70. The standard mconfig options enable various sanitizers during build of the tests. On Linux you may
  71. see an error such as the following:
  72. make[3]: Leaving directory '/home/davmac/workspace/dinit/src/tests/cptests'
  73. ./tests
  74. ==25332==ERROR: AddressSanitizer failed to allocate 0xdfff0001000 (15392894357504) bytes at
  75. address 2008fff7000 (errno: 12)
  76. ==25332==ReserveShadowMemoryRange failed while trying to map 0xdfff0001000 bytes. Perhaps
  77. you're using ulimit -v
  78. make[2]: *** [Makefile:12: run-tests] Aborted
  79. If you get this, either disable the address sanitizer or make sure you have overcommit enabled:
  80. echo 1 > /proc/sys/vm/overcommit_memory
  81. Any test failures will abort the test suite run immediately.
  82. To run the integration tests:
  83. make check-igr
  84. (The integration tests are more fragile than the unit tests, but give a better indication that
  85. Dinit will actually work correctly on your system).
  86. In addition to the standard test suite, there is experimental support for fuzzing the control
  87. protocol handling using LLVM/clang's fuzzer (libFuzzer). Change to the `src/tests/cptests`
  88. directory and build the "fuzz" target:
  89. make fuzz
  90. Then create a "corpus" directory and run the fuzzer:
  91. mkdir corpus
  92. ./fuzz corpus
  93. This will auto-generate test data as it finds input which triggers new execution paths. Check
  94. libFuzzer documentation for further details.
  95. Installation
  96. =-=-=-=-=-=-
  97. You can install using the "install" target:
  98. make install
  99. If you want to install to an alternate root (eg for packaging purposes), specify that root via
  100. DESTDIR:
  101. make DESTDIR=/some/path install
  102. The dinit executable will be put in /sbin (or rather, in $DESTDIR/sbin), which may not be on the
  103. path for normal users. Consider making a symbolic link to /usr/sbin/dinit.
  104. Special note for GCC/Libstdc++
  105. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
  106. (Note: the issue discussed here has apparently been resolved in recent GCC versions).
  107. GCC 5.x onwards includes a "dual ABI" in its standard library implementation, aka Libstdc++.
  108. Compiling against the newer (C++11 and later) ABI can be achieved by adding
  109. -D_GLIBCXX_USE_CXX11_ABI=1 to the compiler command line; this uses a non-standard language
  110. extension to differently mangle symbol names in order to link against the new ABI versions.
  111. (Some systems may be configured to build with the new ABI by default, and in that case you
  112. build against the old ABI using -D_GLIBCXX_USE_CXX11_ABI=0).
  113. This is problematic for several reasons. First, it prevents linking against the new ABI with
  114. other compilers that do not understand the language extension (LLVM i.e. clang++ does so
  115. in recent versions, so this is perhaps no longer much of a problem in practice). Secondly,
  116. some aspects of library behaviour are ABI-dependent but cannot be changed using the ABI
  117. macro; in particular, exceptions thrown as a result of failed I/O operations are, in GCC
  118. versions 5.x and 6.x, always "old ABI" exceptions which cannot be caught by code compiled
  119. against the new ABI, and in GCC version 7.x they are always "new ABI" exceptions which cannot
  120. be caught by code compiled against the old ABI. Since the one library object now supposedly
  121. houses both ABIs, this means that at least one of the two ABIs is always broken.
  122. A blog post describing the dual ABI mechanism can be found here:
  124. The bug regarding the issue with catching other-ABI exceptions is here:
  126. Since Dinit is affected by this bug, the unfortunate possibility exists to break Dinit by
  127. upgrading GCC. If you have libstdc++ corresponding to GCC 5.x or 6.x, you *must* build with
  128. the old ABI, but Dinit will be broken if you upgrade to GCC 7. If you have libstdc++ from
  129. GCC 7, you *must* build with the new ABI. If the wrong ABI is used, Dinit may still run
  130. successfully but any attempt to load a non-existing service, for example, will cause Dinit
  131. to crash.