android exceptions not caught from shared lib

Question

My binary crashes with the following lines

I DEBUG   : pid: 1190, tid: 1367, name: Binder_1  >>> /system/bin/fingerprint_proxy <<<
I DEBUG   : signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
I DEBUG   : Abort message: 'terminating with uncaught exception of type std::__1::ios_base::failure: ios_base::clear: unspecified iostream_category error'

Code that caused the exception looks like this

try {
    std::ofstream out;
    out.exceptions( std::ofstream::failbit | std::ofstream::badbit );
    out.open("bad_path");
} catch(std::ios_base::failure &e) {
    // skipped
}

For some reason exception wasn't caught so i added more catch blocks

try {
    std::ofstream out;
    out.exceptions( std::ofstream::failbit | std::ofstream::badbit );
    out.open("bad_path");
} catch(std::ios_base::failure &e) {
    // skipped
} catch(std::__1::ios_base::failure &e) {
    // skipped
} catch(std::exception &e) {
    // skipped
} catch(...) {
    // caught
}

This time only the last catch block caught the exception, and to be sure it's not an inheritance issue i added.

try {
    throw std::ios_base::failure("miau");
} catch(std::exception &e) {
    // caught
}

My Android.mk looks like this

include $(CLEAR_VARS)

LOCAL_CFLAGS :=  -Wall
LOCAL_CPPFLAGS := -Wno-write-strings -Wall -std=c++11 -fexceptions

LOCAL_SRC_FILES := test.cpp

LOCAL_MODULE := test_app
LOCAL_MODULE_TAGS := optional

include external/libcxx/libcxx.mk
include $(BUILD_EXECUTABLE)

I get std:: namespace and exception implementation from shared library libc++.so which included by "include external/libcxx/libcxx.mk". So i compiled libc++.so staticlly.

include $(CLEAR_VARS)

LOCAL_CFLAGS :=  -Wall
LOCAL_CPPFLAGS := -Wno-write-strings -Wall -std=c++11 -fexceptions

LOCAL_SRC_FILES := test.cpp

LOCAL_MODULE := test_app
LOCAL_MODULE_TAGS := optional

LOCAL_SHARED_LIBRARIES := libc++

include external/libcxx/libcxx.mk
include $(BUILD_EXECUTABLE)

And it worked!

Exceptions were caught by std::exception clause, although it multiplied binary size by 8, so this is not a solution.

So it seems like exceptions that thrown by shared library are not caught.

Any one has idea why?

A gist for your convenience https://gist.github.com/amfern/2377e9a3cd1ccc0186ea

amfern amfern · Accepted Answer · 2015-08-31T13:13:02

Adding -frtti to LOCAL_CPPFLAGS solved the problem.

Because exceptions use RTTI internally, not specifying -frtti flag will resulting in two tables, one coming from libc++ and one for my binary. exceptions under the hood

Notice: As all android native libraries are compiled without RTTI, which makes it is impossible to include them in -frtti compiled binary/library.

android exceptions not caught from shared lib

1 Answers