#!/bin/bash

# Simulate make for the given target(s) (can also be empty), printing the
# resulting "big makefile" to stdout.
#
# Use this script if you want to see what is going during complex builds
# without having to browse dozens of included sub-makefiles. Now you get it
# all in one place and are even able to re-run make with the big makefile.
#
# How to use:
#
# Simulate "make" (default target) in current directory and write resulting
# big makefile to 'Makefile.big'. Then re-run with another target, using big
# makefile as input.
#
# tools/developer/big-makefile > Makefile.big
# make -f Makefile.big config-cache

# Print cleaned-up version of big makefile, i.e.
#   - use LC_ALL=C to avoid some German "Konnte nicht geöffnet werden" messages
#     on stdout which should actually go to stderr. This bug does not happen
#     for LC_ALL=C in GNU make 3.81.
#   - remove consecutive lines which are empty or contain only whitespace,
#     leaving only one empty line per block
#   - remove some Make variables possibly blocking a later re-run
LC_ALL=C make --print-data-base --question $@ \
	| sed -r 's/^[[:space:]]+$//' \
	| grep -Ev '^[[:space:]]*#|MAKEFLAGS|MFLAGS|MAKECMDGOALS' \
	| cat -s