Compiler options in Android.bp files

Question

I'm trying to convert a makefile to a .bp file for Android Q and I'm facing some issues.

1. I'm not sure how to define a release version. Previously in makefile i would just write something along the lines of:

   MY_RELEASE_VERSION := $(shell cd $(LOCAL_PATH); git describe --always --dirty) DSW_VERSION= \"$(MY_RELEASE_VERSION)\"

Which would be defined as a string like for example: DSW_VERSION="project_specific_3_0"

Now I am able to use a cppflag in .bp with the DSW_VERSION , but I found no way to make the value of it to be taken like in the makefile. Something like:

MY_RELEASE_VERSION = ["__builtin_func:shell cd <'LOCAL_PATH' unset>; git describe --always --dirty"]
CPPFLAGS = [
 "DSW_VERSION = "\"MY_RELEASE_VERSION"\",
]

Does not work.

Secondly I'm facing issues in defining a config variant, which in turn would define a variable from the source code. Something like this in .mk files:

LOCAL_CPPFLAGS +=$(TARGET_CONFIG)

With a ifdefined in the code that looks like this:

#if defined (TARGET_ONE)
    static const VAR   = 1;
#elif defined (TARGET_TWO)
    static const VAR     = 2; 

I tried in .bp appending to the cppflags, something like : cppflags: MY_CPPFLAGS + TARGET_CONFIG, where MY_CPPFLAGS is a variable defined with all the flags needed and it doesn't work

Anyone can help me with those?

Answer 1

You can use genrule to generate code at build time (e.g. a header file containing the repository version). Check out the Wayland Android.bp as an example on how a genrule looks like.

To answer your second question: You can use cflags to add defines:

<some-module> {
    [...]
    cflags: ["-DTARGET_CONFIG"],
}