Scenario:
```
export CURL=libsodium
cd zyre/builds/android
./ci_build.sh
```
Result:
```
Android (arm) build failed for the following reasons:
Found no library named libzmq.so libsodium.so
/home/stephan/git/zproject-android-testing/libzmq/builds/android/prefix/arm/lib/libzmq.so libsodium.so
```
Caused by PR #4437, where the 2nd commit was to fix Sonatype findings.
Lesson learnt: Not always a good idea to add double quotes around variables ...
Solution: Make VERIFY an array, so that Sonatype won't complain.
Seen when someone has to relaunch `ci_build.sh` manually, for troubleshooting,
or experiment(s), ci_build.sh stops as libraries are already built.
Solution: Clean more temporary/build folders before build.
Note:
To be reported in ZYRE/CZMQ via ZProject.
When called from ZYRE/CZMQ, it's difficult to identify which build script is
being executed
Solution: Modify each `echo` trace to show the project name and Android architecture in progress.
Note:
To be reported in ZYRE/CZMQ via ZProject.
* Problem: Android APP fails to load ZMQ since NDK r25.x
With the help of the dump of ./configure options (former PR):
```
LIBZMQ (arm) - ./configure options to build 'LIBZMQ':
> --quiet
> TOOLCHAIN=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64
> CC=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang
> CXX=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi21-clang++
> LD=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/ld
> AS=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-as
> AR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ar
> RANLIB=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ranlib
> STRIP=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-strip
> CFLAGS= -D_GNU_SOURCE -D_REENTRANT -D_THREAD_SAFE
> CPPFLAGS= -I/home/stephan/git/zproject-android-testing/libzmq/builds/android/prefix/arm/include
> CXXFLAGS=
> LDFLAGS=-L/home/stephan/git/zproject-android-testing/libzmq/builds/android/prefix/arm/lib -L/tmp/android-ndk-r25/sour\
ces/cxx-stl/llvm-libc++/libs/armeabi-v7a
> LIBS=-lc -ldl -lm -llog -lc++_shared
> PKG_CONFIG_LIBDIR=/tmp/android-ndk-r25/prebuilt/linux-x86_64/lib/pkgconfig
> PKG_CONFIG_PATH=/home/stephan/git/zproject-android-testing/libzmq/builds/android/prefix/arm/lib/pkgconfig
> PKG_CONFIG_SYSROOT_DIR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> PKG_CONFIG_DIR=
> --with-sysroot=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> --host=arm-linux-androideabi
> --prefix=/home/stephan/git/zproject-android-testing/libzmq/builds/android/prefix/arm
> --disable-curve
> --without-docs
```
We can observe that LDFLAGS has invalid `-L<path_to_libc++_shared.so>`:
```
-L/tmp/android-ndk-r25/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a
```
This path is no more valid, since NDK r25, where one should use LLVM path.
Ok, once this is fixed, ./configure requires also the path to libc.so.
I don't understand why libc.so is now required, actually, but without this, ./configure fails
to build its conftest.
Solution: Fix invalid LDFLAGS.
Notes:
- To be reported to CZMQ/ZYRE via ZPROJECT.
- Tested successfully with Android Emulator (x86 & x86_64).
- Still need some more work, as execution still fails with physical devices (observed on arm64).
- Introduced `ANDROID_STL`, `ANDROID_STL_ROOT` & `ANDROID_LIBC_ROOT`. All are initialized in `android_build_helper.sh`.
- New mechanism **MUST** be compatible with former NDK versions.
Proposal is to dump ./configure options to have an output like below:
```
LIBZMQ (x86_64) - ./configure options to build 'LIBZMQ':
> --quiet
> TOOLCHAIN=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64
> CC=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang
> CXX=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang++
> LD=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/ld
> AS=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-as
> AR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ar
> RANLIB=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-ranlib
> STRIP=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-strip
> CFLAGS= -D_GNU_SOURCE -D_REENTRANT -D_THREAD_SAFE
> CPPFLAGS= -I/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/include
> CXXFLAGS=
> LDFLAGS=-L/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/lib -L/tmp/android-ndk-r25/sources/cxx-stl/llvm-libc++/libs/x86_64
> LIBS=-lc -ldl -lm -llog -lc++_shared
> PKG_CONFIG_LIBDIR=/tmp/android-ndk-r25/prebuilt/linux-x86_64/lib/pkgconfig
> PKG_CONFIG_PATH=/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64/lib/pkgconfig
> PKG_CONFIG_SYSROOT_DIR=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> PKG_CONFIG_DIR=
> --with-sysroot=/tmp/android-ndk-r25/toolchains/llvm/prebuilt/linux-x86_64/sysroot
> --host=x86_64-linux-android
> --prefix=/builds/CrisalidBox/zproject-android-testing/libzmq/builds/android/prefix/x86_64
> --disable-curve
> --without-docs
```
Note:
This mechanism is currently in use to identify/fix a bug in a recent PR for NDK update.
This mechanism is added before every call of `./configure`.
To be reported to CZMQ/ZYRE (via ZPROJECT).
Solution: Use `set -e`
Note:
To be reported in ZPROJECT, when generating the same for CZMQ & ZYRE.
Note:
`make clean` may fail when Makefile is not yet generated
(case of 1st call of build.sh after git clone).
Additionnaly, cleaned the dependency folder
(report of ZPROJECT generated scripts).
Seen in the code:
```
function android_build_verify_so {
...
for dep_soname do
if [[ $elfoutput != *"library: [${dep_soname}]"* ]]; then
ANDROID_BUILD_FAIL+=("Library ${soname} was expected to be linked to library with soname:")
ANDROID_BUILD_FAIL+=(" ${dep_soname}")
fi
done
```
The `for xxx` syntax is wrong, most probably a typo somewhere.
Solution: Fix & complete the `for xxx` loop.
Tested with & without LIBSODIUM (only available dependent library for LIBZMQ).
Note: The same has to be done in ZPROJECT, for CZMQ & ZYRE.
Solution: Modify the build scripts so the user can specify the platform
for which to build, e.g. `./build.sh arm`. This approach originally
significantly reduces the parameters which have to be set before running
the script.
Further the build process is documented in a README now.
Solution: Migrate build scripts from Android NDK r11c to r20.
- Standalone toolchain
- Migration from GCC to Clang
- Migration from libgnustl to libc++
- Dropped support for API level below 16 (Android 4.1), previously it was API level 9 (Android 2.3)
- Dropped support for mips architecture
- The build script now start the build of all 4 Android architectures (arm, arm64, x86, x86_64)
Solution: set the appropriate options, environment variables and paths
so that the host pkg-config files are ignored, and the target ones are
used instead (if any)
Solution: establish a matrix of CI options. On one axis we have the
build system (autotools, cmake, android) and on the other axis we
have the encryption options (tweetnacl, libsodium or none).
