Re: Library dependency files

[Erik Rull]

Todd Showalter wrote:
>     We're case b, but the problem remains.  I'll try to give a more
> concrete example:
>
>     Say we've got an environment variable, $BUILD_NETWORK_SUPPORT, and
> it's currently set to 0.  Within the makefile we have
>
> CFLAGS+= -DBUILD_NETWORK_SUPPORT=$(BUILD_NETWORK_SUPPORT)
>
>     Within a C file we have:
>
> #if (BUILD_NETWORK_SUPPORT == 1)
> #include "Network.h"
> #else
> #include "Network.Stub.h"
> #endif
>
>     Now say on the command line I do:
>
> make
> export BUILD_NETWORK_SUPPORT=1
> make
>
>     The second invocation of make will not detect the change, and the
> dependencies will be wrong.

Simple solution:
- write down the current parameter settings that will be changed via 
Makefile parameters into a file (e.g. echo -en "$(CFLAGS)" > 
compile_settings.txt; syntax might be wrong, just to show what I want to 
express)
- read the file and compare it to the "current" settings string. If 
different do a clean and then a make and sync the file with the most recent 
parameters

You just need a function in your makefile how to create the string and how 
to read the file and compare it and what to do if it has changed.

Should be possible to be solved with pure make.

Best regards,

Erik