Re: Force Rebuild if CXXFLAGS Change?

[Oleksandr Gavenko]

11.08.2011 10:27, Jeffrey Walton пишет:
> Hi All,
>
> Is it possible to have make rebuild a target if its CXXFLAGS change?
> For example:
>
>      `make debug`   # CXXFLAGS = -D_GLIBCXX_DEBUG -DDEBUG=1 -g3 -ggdb -O0
>      <user runs debug build>
>      `make release`   #CXXFLAGS = -DNDEBUG=1 -g -O2
>      <make: nothing to make>
Hi Jeff! I use such technique:


################################################################
# Build files definition.

# Makefile itself.
MK_FILE := $(firstword $(MAKEFILE_LIST))
# Storage for CLI options.
MK_CLI_FILE := $(patsubst %,build/%.cli,$(MK_FILE))
BUILD_SCRIPTS += $(MK_FILE)

################################################################
# Force rebuild project if in CLI you change valuable options.

-include $(MK_CLI_FILE)
$(shell mkdir -p $(dir $(MK_CLI_FILE)); printf "DEBUG_OLD=$(DEBUG)\n" 
>$(MK_CLI_FILE))
ifneq '$(DEBUG_OLD)' '$(DEBUG)'
  $(shell touch $(MK_FILE))
endif

%.o: %.c  $(BUILD_SCRIPTS)   # Place dependency on makefile to all 
xxx                          # target that build something...

So  if I build with debug ON next time if I build with debug OFF
make rebuild all targets marked by $(BUILD_SCRIPTS).


--
С уважением, Александр Гавенко.