test-librsloader target fails to build on ubuntu 12.04

[Zygmunt Krynicki]

This bug hampers my local development / research as I simply cannot successfully build the 'tests' variant locally.

The build failure seems to be:

 * libLLVMSupport.a requires -lpthreads -ldl
 * something links to that library
 * it fails to specify those depencencies

I'm trying to understand the build system enough to know if the linkage dependencies are defined in one place (for each .a) or is this a separate per-executable responsibility.

The actual build can be reproduced by https://github.com/zyga/android-build-scripts

The actual error message is:

host Executable: test-librsloader (out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/test-librsloader)
out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a(Signals.o): In function `PrintStackTrace':
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Unix/Signals.inc:219: undefined reference to `dladdr'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Unix/Signals.inc:231: undefined reference to `dladdr'
out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a(Threading.o): In function `llvm::llvm_execute_on_thread(void (*)(void*), void*, unsigned int)':
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Threading.cpp:96: undefined reference to `pthread_create'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Threading.cpp:91: undefined reference to `pthread_attr_setstacksize'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Threading.cpp:100: undefined reference to `pthread_join'
out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a(Mutex.o): In function `MutexImpl':
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Mutex.cpp:69: undefined reference to `pthread_mutexattr_init'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Mutex.cpp:75: undefined reference to `pthread_mutexattr_settype'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Mutex.cpp:80: undefined reference to `pthread_mutexattr_setpshared'
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Mutex.cpp:89: undefined reference to `pthread_mutexattr_destroy'
out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::tryacquire()':
/home/zyga/Android/panda-ics-gcc47-tilt-tracking-tests-blob/android/external/llvm/lib/Support/Mutex.cpp:143: undefined reference to `pthread_mutex_trylock'
collect2: ld returned 1 exit status
make: *** [out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/test-librsloader] Error 1

[Zygmunt Krynicki (zyga)]

It seems to be coming from

/frameworks/compile/linkloader/Android.mk

specifically librsloader-test (Host) executable

[Zygmunt Krynicki (zyga)]

Seems to be reproducible on my host with:

$ make test-librsloader showcommands

The command it executes is:

g++ -Wl,-rpath-link=out/host/linux-x86/obj/lib -Wl,-rpath,\$ORIGIN/../lib -Lout/host/linux-x86/obj/lib -lpthread -ldl -Wl,--no-undefined -Wl,-O2 -m32 out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/android/test-librsloader.o -Wl,--whole-archive -Wl,--no-whole-archive out/host/linux-x86/obj/STATIC_LIBRARIES/librsloader_intermediates/librsloader.a out/host/linux-x86/obj/STATIC_LIBRARIES/liblog_intermediates/liblog.a out/host/linux-x86/obj/STATIC_LIBRARIES/libcutils_intermediates/libcutils.a out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a -o out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/test-librsloader

It obviously ignores LOCAL_LDFLAGS that specify the missing required dependencies.

[Zygmunt Krynicki (zyga)]

Ah, my blind eye, it's obvious what the problem is, the static libraries that really require -ldl and -lpthread (libLLVMSupport.a) are listed _AFTER_ -l{dl,pthread}

[Zygmunt Krynicki (zyga)]

Digging deeper:

The rule that builds executables is defined in: build/core/definitions.mk in the transform-host-o-to-executable-inner variable

This is how it looks like

ifneq ($(HOST_CUSTOM_LD_COMMAND),true)
define transform-host-o-to-executable-inner
$(hide) $(PRIVATE_CXX) \
    -Wl,-rpath-link=$(HOST_OUT_INTERMEDIATE_LIBRARIES) \
    -Wl,-rpath,\$$ORIGIN/../lib \
    $(HOST_GLOBAL_LD_DIRS) \
    $(PRIVATE_LDFLAGS) \
    $(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
        $(HOST_GLOBAL_LDFLAGS) \
    ) \
    $(PRIVATE_ALL_OBJECTS) \
    -Wl,--whole-archive \
    $(call normalize-host-libraries,$(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES)) \
    -Wl,--no-whole-archive \
    $(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--start-group) \
    $(call normalize-host-libraries,$(PRIVATE_ALL_STATIC_LIBRARIES)) \
    $(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--end-group) \
    $(call normalize-host-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
    -o $@ \
    $(PRIVATE_LDLIBS)
endef
endif

 Based on that I simply thing that instead of saying

LOCAL_LDFLAGS = ...

the test should simply state

LOCAL_LDLIBS = ...

[Zygmunt Krynicki (zyga)]

Grepping the whole tree like this:

$ grep -A 6 -R LOCAL_LDFLAGS . 2>/dev/null

Reveals another case that seem to make the same mistake (again in tests), specifically:

 ./system/extras/tests/bionic/libc/Android.mk:LOCAL_LDFLAGS := -ldl

Every other reference to LOCAL_FLAGS are inside the core build system or documentation.

[Zygmunt Krynicki (zyga)]

This patch fixes this problem for me

[Zygmunt Krynicki (zyga)]

Assigning to myself, setting current milestone

[Bernhard Rosenkraenzer (berolinux)]

The patch looks good to me... Just makes me wonder why it works for me and on android-build even without the patch.

[Zygmunt Krynicki (zyga)]

W dniu 28.06.2012 17:58, Bernhard Rosenkraenzer pisze:
> The patch looks good to me... Just makes me wonder why it works for me
> and on android-build even without the patch.
>

Yeah. I wonder that too.

Please don't apply it yet. I want to propose it to gerrit to see how
that works myself, ok?

Thanks
ZK

[Zygmunt Krynicki (zyga)]

Submitted for review:
http://review.android.git.linaro.org/#change,2357
http://review.android.git.linaro.org/#change,2358

[Zygmunt Krynicki (zyga)]

http://review.android.git.linaro.org/#change,2359 (replacing change 2357)

[Zygmunt Krynicki (zyga)]

Merged to linaro branch

[mrzhang (zgd-521)]

This problem have been soloved in android 4.2.

[changson (changson0823)]

I am compiling linaro-android 4.0.4 on ubuntu 12.04 64bit
I resules the problem with try:

 #gedit external/llvm/llvm-host-build.mk

Add:
  LOCAL_LDLIBS := -lpthread -ldl

Good luck!