How to support C++ exceptions?

[JoeStrout]

I'm trying to incorporate a library that makes use of throw and catch. They're not heavily used, but it would require pretty major architecture changes to get rid of them.

I added CFLAGS += "-fexceptions" to my makefile, and it compiles now, but fails at the linker stage.

arm-none-eabi-ld: main.o: in function `main':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/main.cpp:47:(.text.startup+0x48): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: main.o:(.ARM.extab.text.startup+0x0): undefined reference to `__gxx_personality_v0'
arm-none-eabi-ld: kernel.o: in function `CKernel::CKernel()':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/kernel.cpp:31:(.text+0x260): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: kernel.o: in function `CKernel::Initialize()':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/kernel.cpp:56:(.text+0x42c): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: kernel.o: in function `CKernel::KeyStatusHandlerRaw(unsigned char, unsigned char const*)':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/kernel.cpp:157:(.text+0x7bc): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: kernel.o:(.ARM.extab+0x0): undefined reference to `__gxx_personality_v0'
arm-none-eabi-ld: kernel.o:(.ARM.extab+0x48): undefined reference to `__gxx_personality_v0'
arm-none-eabi-ld: kernel.o:(.ARM.extab+0x64): undefined reference to `__gxx_personality_v0'
arm-none-eabi-ld: tests.o: in function `MiniScript::RefCountedStorage::release()':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/MiniScript/RefCountedStorage.h:25:(.text+0xf8): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: tests.o: in function `MiniScript::String::String(char const*)':
/Users/jstrout/svnrepo/circle/MiniScript-Pi/MiniScript/SimpleString.h:220:(.text+0x108): undefined reference to `__cxa_end_cleanup'
arm-none-eabi-ld: tests.o:(.ARM.extab+0x0): undefined reference to `__gxx_personality_v0'
arm-none-eabi-ld: /Applications/ArmGNUToolchain/13.2.Rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/13.2.1/thumb/v8-a+simd/hard/libgcc.a(unwind-arm.o): in function `unwind_phase2':
unwind-arm.c:(.text.unwind_phase2+0x36): undefined reference to `abort'
arm-none-eabi-ld: /Applications/ArmGNUToolchain/13.2.Rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/13.2.1/thumb/v8-a+simd/hard/libgcc.a(unwind-arm.o): in function `__gnu_Unwind_Resume':
unwind-arm.c:(.text.__gnu_Unwind_Resume+0x3c): undefined reference to `abort'
arm-none-eabi-ld: unwind-arm.c:(.text.__gnu_Unwind_Resume+0x40): undefined reference to `abort'
arm-none-eabi-ld: /Applications/ArmGNUToolchain/13.2.Rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/13.2.1/thumb/v8-a+simd/hard/libgcc.a(pr-support.o): in function `_Unwind_GetDataRelBase':
pr-support.c:(.text.unlikely._Unwind_GetDataRelBase+0x2): undefined reference to `abort'

Any idea how I could make this work? (Apologies if this seems obvious, my C++ is rusty and my make skills were never very good to begin with!)

[rsta2]

It's not that simple, but there is a solution. You should have a look at the circle-stdlib project by @smuehlst, which provides C and C++ standard lib support for Circle, including support for C++ exceptions: https://github.com/smuehlst/circle-stdlib

[JoeStrout]

Thank you. I guess this would also be the solution for using things like (for trig functions, etc.)?

Is there an easy way to know which standard lib modules are already available in Circle, and which are not? Right now I just notice that if I use certain headers, make exits with status 2 (without printing any error, but also without completing its job).

[rsta2]

You are welcome. Yes, with the circle-stdlib project most of the C and C++ standard lib features (e.g. math, containers) can be used. With plain Circle and the toolchain, you are using, you should be able to include <math.h> and <stdint.h>, but not more. Circle implements some utility functions (e.g. strcpy()) on its own in <circle/util.h>, but circle-stdlib provides much more of this.