docs/static_initializers.md

   1 # Static Initializers
   2
   3 [TOC]
   4
   5 Some background on the original decision to ban static initializers:
   6
   7 http://neugierig.org/software/chromium/notes/2011/08/static-initializers.html
   8
   9 # How Static Initializers are Checked
  10
  11 * For Linux and Mac:
  12   * The expected count is stored in [//infra/scripts/legacy/scripts/slave/chromium/sizes.py](https://cs.chromium.org/chromium/src/infra/scripts/legacy/scripts/slave/chromium/sizes.py)
  13 * For Android:
  14   * The expected count is stored in the build target [//chrome/android:monochrome_static_initializers](https://cs.chromium.org/chromium/src/chrome/android/BUILD.gn)
  15
  16 ## Removing Static Initializers
  17
  18 Common fixes include:
  19
  20 * Add constexpr,
  21 * Use LazyInstance<>,
  22 * Move global variable to be a static variable within a function that returns it.
  23
  24 ## Listing Static Initializers
  25
  26 For Linux:
  27
  28     tools/linux/dump-static-initializers.py out/Release/chrome
  29
  30 For Android (from easiest to hardest):
  31
  32     # Build with: is_official_build=true is_chrome_branded=true
  33     # This will dump the list of SI's only when they don't match the expected
  34     # number in static_initializers.gni (this is what the bots use).
  35     ninja chrome/android:monochrome_static_initializers
  36     # or:
  37     tools/binary_size/diagnose_bloat.py HEAD  # See README.md for flags.
  38     # or:
  39     tools/linux/dump-static-initializers.py --toolchain-prefix third_party/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/bin/arm-linux-androideabi- out/Release/libmonochrome.so
  40
  41 * For more information about `diagnose_bloat.py`, refer to its [README.md](/tools/binary_size/README.md#diagnose_bloat.py)
  42 * List of existing static initializers documented in [static_initializers.gni](/chrome/android/static_initializers.gni)