Static Initializers

Some background on the original decision to ban static initializers:

http://neugierig.org/software/chromium/notes/2011/08/static-initializers.html

How Static Initializers are Checked

For Linux and Mac:
- The expected count is stored in //infra/scripts/legacy/scripts/slave/chromium/sizes.py
For Android:
- The expected count is stored in the build target //chrome/android:monochrome_static_initializers

Removing Static Initializers

Common fixes include:

Add constexpr.
Move global variable to be a static variable within a function that returns it, often wrapped in base::NoDestructor.

Listing Static Initializers

Method 1 - Ask compiler to report them

Edit //build/config/BUILDCONFIG.gn and add "//build/config/compiler:wglobal_constructors" to default_compiler_configs
Set GN arg treat_warnings_as_errors=false
Compile and look at warnings

This will produce far more warnings than there are static initializers because it (seems to) trigger on global variables initialized with constexpr constructors.

Method 2 - Use objdump to report them

For Linux:

tools/linux/dump-static-initializers.py out/Release/chrome

For Android (from easiest to hardest):

# Build with: is_official_build=true is_chrome_branded=true
# This will dump the list of SI's only when they don't match the expected
# number in static_initializers.gni (this is what the bots use).
ninja chrome/android:monochrome_static_initializers
# or:
tools/binary_size/diagnose_bloat.py HEAD  # See README.md for flags.
# or:
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

For more information about diagnose_bloat.py, refer to its README.md
List of existing static initializers documented in static_initializers.gni