Hello,

I try to compile tiny and optimized code using the lastest NDK.

I use Neon instructions thus, the Android.mk file contains : LOCAL_ARM_NEON
:= true.

Moreover, I don't need to debug my code (i.e. no debug symbols needed), so
the Application.mk file contains : APP_OPTIM := release.

Then, when I execute 'ndk-build -n' to see the compile commands, I found
some misterious g++ options :

   - -g : to generate debug symbols
   - -march=armv7-a -mfloat-abi=softfp -mfpu=vfp [..] -mfpu=neon : 2 fpu
   options, AFAIK only the last one is needed in my case, but gcc maybe only
   takes the last one ?

However, even if the fpu options are good (can you confirm ?), is there a
way to drop the '-g' parameter. Indeed, this option enlarges the size of
the lib with useless symbols.

Thanks a lot !

Jérôme

The -g parameter is intended, and doesn't impact your final binaries, i.e.
it doesn't enlarge the size of the final binaries.

In a nutshell:

- intermediate libraries that are placed under obj/local/<abi>/ are built
with -g to contain debug symbols, even for optimized code.
- the final libraries that are put under lib/<abi>/, and which end up in
your .apk, are *stripped* from any debug symbols.

The point of the debug symbols under obj/local/<abi>/ is that it makes
tools like ndk-stack useful when you get a crash in your optimized code.
You can use ndk-stack to use the debug information under obj/local/<abi>/
to know exactly where the problem happened.

There is no impact on the size of the final stripped binaries, with our
without -g, so don't worry about it. And there is no way to disable this
right now.

Second, yes, gcc will only take the last one, to as long as it ends with
-mfpu=neon, you're good. You would probably won't be able to compile your
sources otherwise.