Multiple definition of '__aeabi_uidivmod' and '__aeabi_uldivmod' on arm-linux-androideabi

[petrochenkov]

In rust-lang/rust#83822 I attempted to remove the --allow-multiple-definition linker hack from Android target specs in rustc, but observed the next linking error:

error: linking with `/android/ndk/arm-14/bin/arm-linux-androideabi-clang` failed: exit status: 1
  |
  = note: "/android/ndk/arm-14/bin/arm-linux-androideabi-clang" "-Wl,--eh-frame-hdr" "-Wl,-znoexecstack" "-Wl,--as-needed" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/arm-linux-androideabi/lib" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/deps/std-aa02b9ba56c47188.std.1gj5x857-cgu.0.rcgu.o" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/deps/libstd-aa02b9ba56c47188.so" "-Wl,--version-script=/tmp/rustcsKqBUX/list" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/deps/std-aa02b9ba56c47188.550hwdqflrivilit.rcgu.o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/deps/std-aa02b9ba56c47188.f3uuzluee2cbevv.rcgu.o" "-shared" "-Wl,-zrelro" "-Wl,-znow" "-Wl,-O1" "-nodefaultlibs" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/deps" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/release/deps" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/build/compiler_builtins-0cc9b3ede123fcbb/out" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-std/arm-linux-androideabi/release/build/profiler_builtins-f00fa99f86511a66/out" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/arm-linux-androideabi/lib" "-ldl" "-llog" "-lgcc" "-Wl,-Bstatic" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libpanic_unwind-53a82f532deef78c.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libminiz_oxide-5ae569e4d71b98f2.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libadler-480e8a29cd327522.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libobject-818d6dece30befc6.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libaddr2line-83e55526cd23350a.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libgimli-d880f99d5b85d10a.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/librustc_demangle-cd2642fb698e70d6.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libhashbrown-a9c6975bf97337e1.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/librustc_std_workspace_alloc-12a29a9bfdad4d51.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libunwind-7de75771c758f0b5.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libcfg_if-7dbf72bdfaf506c0.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/liblibc-f48e19d6fccfbd3c.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/liballoc-cddf24203f98dfca.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/librustc_std_workspace_core-751cff066ed2ddff.rlib" "-Wl,--no-whole-archive" "-Wl,--whole-archive" "/tmp/rustcsKqBUX/libcore-61aecf05f20b0be0.rlib" "-Wl,--no-whole-archive" "/tmp/rustcsKqBUX/libcompiler_builtins-fa77a8df7f01d459.rlib" "-Wl,-Bdynamic" "-lc" "-lm" "-Wl,-rpath,$ORIGIN/../lib"
  = note: /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin/ld: error: /tmp/rustcsKqBUX/libcompiler_builtins-fa77a8df7f01d459.rlib(compiler_builtins-fa77a8df7f01d459.compiler_builtins.1pwrvrkl-cgu.55.rcgu.o): multiple definition of '__aeabi_uidivmod'
          /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin/ld: /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/armv7-a/libgcc.a(_udivsi3.o): previous definition here
          /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin/ld: error: /tmp/rustcsKqBUX/libcompiler_builtins-fa77a8df7f01d459.rlib(compiler_builtins-fa77a8df7f01d459.compiler_builtins.1pwrvrkl-cgu.55.rcgu.o): multiple definition of '__aeabi_uldivmod'
          /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../arm-linux-androideabi/bin/ld: /android/ndk/arm-14/bin/../lib/gcc/arm-linux-androideabi/4.9.x/armv7-a/libgcc.a(_aeabi_uldivmod.o): previous definition here
          clang50: error: linker command failed with exit code 1 (use -v to see invocation)

Previously compiler-builtins fixed similar errors on other targets by putting symbols to separate object files or changing linking order.

It would be great to fix this case as well, and remove --allow-multiple-definition from Android target specs.
That option is a really heavy hammer used when everything is on fire but you still need to make things work, and it is able to hide legitimate errors.

[Amanieu]

compiler-builtins should be getting built with maximal codegen units (enabled by the #![cfg_attr(feature = "compiler-builtins", compiler_builtins)] at the top of the crate).

This should result in every function getting built in a separate object file, but it doesn't seem to be happening here for some reason: the linker error shows that both __aeabi_uidivmod and __aeabi_uldivmod are located in the same object file compiler_builtins-fa77a8df7f01d459.compiler_builtins.1pwrvrkl-cgu.55.rcgu.o.

[bjorn3]

The functions are not placed in their own module. Rustc starts codegen unit partitioning with modules, not individual functions. The intrinsics! macro does this automatically:

compiler-builtins/src/macros.rs

Lines 266 to 272 in e6fd1b2

	pub mod $name {
	$(#[$($attr)*])*
	#[cfg_attr(not(feature = "mangled-names"), no_mangle)]
	pub extern $abi fn $name( $($argname: $ty),* ) -> $ret {
	super::$name($($argname),*)
	}
	}

[d3zd3z]

I am encountering this same issue trying to build a Zephyr application in Rust. I was able to workaround it by changing the Zephyr build system to place -lgcc after the .a for my Rust application.

[Amanieu]

Hopefully this should be fixed by #452 which will be included in rust-lang/rust#93696. Please try it in the next nightly once that is merged.

[petrochenkov]

This issue was fixed, and --allow-multiple-definition was removed from Android targets.