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copied!<p><strong>Where to find: __aeabi_unwind_cpp_pr0 and other mysterious, undefined functions</strong></p> <p>(I had a similar problem error to what you describe, but found a different solution, that may be helpful to you or others)</p> <p>I found 'libgccunwind.a' library in the Google NDK package which defines a number of these mysterious functions (they are functions referenced by libc.a and other libraries in the NDK package, but not defined in a standard library) I found them defined in a libgccunwind.a library in:</p> <p>\sources\android\gccunwind\libs\armeabi</p> <p>NM shows that they are defined in that lib from an 'unwind-arm.o' file:</p> <pre><code>nm libgccunwind.a unwind-arm.o: U _GLOBAL_OFFSET_TABLE_ 00000cf8 T _Unwind_Complete 00000cfc T _Unwind_DeleteException 00000ba4 T _Unwind_GetCFA 00000408 t _Unwind_GetGR 00000474 t _Unwind_SetGR 000003c4 T _Unwind_VRS_Get 0000084c T _Unwind_VRS_Pop 00000430 T _Unwind_VRS_Set 00000844 T __aeabi_unwind_cpp_pr0 0000083c W __aeabi_unwind_cpp_pr1 00000834 W __aeabi_unwind_cpp_pr2 w __cxa_begin_cleanup w __cxa_call_unexpected w __cxa_type_match U __exidx_end U __exidx_start 00000d1c T __gnu_Unwind_Backtrace w __gnu_Unwind_Find_exidx </code></pre> <p>Independant of the libgccunwind.a above, I searched for __aeabi_unwind_cpp_pr0 and unwind-arm.c and unwind.c, and found various c source, for example:</p> <p><a href="http://lxr.free-electrons.com/source/arch/arm/kernel/unwind.c?a=arm" rel="nofollow">http://lxr.free-electrons.com/source/arch/arm/kernel/unwind.c?a=arm</a></p> <p><a href="http://opensource.apple.com/source/gcc/gcc-5646/gcc/config/arm/unwind-arm.c" rel="nofollow">http://opensource.apple.com/source/gcc/gcc-5646/gcc/config/arm/unwind-arm.c</a></p> <p>These programs seem to be derived from a similar source. My guess is that these 'unwind_cpp' (and related functions) are called by the functions in libc.a when a function returns or on certain events so that these functions can perform some debugging or tracing operation. </p> <p>In any event, adding that directory in a -L linker option and -lgccunwind linker option (after the -lc linker option) allowed the linker to find those 'undefined' functions -- and let me get to the next problem I have in cross compiling to ARM systems.</p>

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