Could not compile core - LLVM Error: Cannot Select

[jonahbron]

I just built the latest from the avr-support-upstream branch the other day (6a48e6e). When compiling another library (avr-hal), it tries to build core and fails.

jonah@jonah-desktop-linux/run/media/jonah/data/Projects/avr-hal $ XARGO_RUST_SRC=/run/media/jonah/data/Projects/avr-rust/src cargo +avr xbuild --target avr-unknown-unknown --verbose
WARNING: There is no root package to read the cargo-xbuild config from.
+ "rustc" "--print" "sysroot"
+ "rustc" "--print" "target-list"
+ "/home/jonah/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo" "rustc" "-p" "alloc" "--release" "--manifest-path" "/tmp/xargo.s99JD96fQHru/Cargo.toml" "--target" "avr-unknown-unknown" "-v" "--" "-Z" "force-unstable-if-unmarked"
    Updating crates.io index
   Compiling compiler_builtins v0.1.26
   Compiling core v0.0.0 (/run/media/jonah/data/Projects/avr-rust/src/libcore)
     Running `rustc --crate-name build_script_build /home/jonah/.cargo/registry/src/github.com-1ecc6299db9ec823/compiler_builtins-0.1.26/build.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C opt-level=s -C codegen-units=1 --cfg 'feature="compiler-builtins"' --cfg 'feature="core"' --cfg 'feature="default"' --cfg 'feature="mem"' -C metadata=8f88709af7275f23 -C extra-filename=-8f88709af7275f23 --out-dir /tmp/xargo.s99JD96fQHru/target/release/build/compiler_builtins-8f88709af7275f23 -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps --cap-lints allow`
     Running `rustc --crate-name core --edition=2018 /run/media/jonah/data/Projects/avr-rust/src/libcore/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C panic=abort -C codegen-units=1 -C metadata=0425a61751752881 -C extra-filename=-0425a61751752881 --out-dir /tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps --target avr-unknown-unknown -L dependency=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps`
     Running `/tmp/xargo.s99JD96fQHru/target/release/build/compiler_builtins-8f88709af7275f23/build-script-build`
   Compiling rustc-std-workspace-core v1.99.0 (/run/media/jonah/data/Projects/avr-rust/src/tools/rustc-std-workspace-core)
     Running `rustc --crate-name rustc_std_workspace_core --edition=2018 /run/media/jonah/data/Projects/avr-rust/src/tools/rustc-std-workspace-core/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C panic=abort -C codegen-units=1 -C metadata=1d5b7545d773d921 -C extra-filename=-1d5b7545d773d921 --out-dir /tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps --target avr-unknown-unknown -L dependency=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps --extern core=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps/libcore-0425a61751752881.rmeta`
     Running `rustc --crate-name compiler_builtins /home/jonah/.cargo/registry/src/github.com-1ecc6299db9ec823/compiler_builtins-0.1.26/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C panic=abort -C codegen-units=1 --cfg 'feature="compiler-builtins"' --cfg 'feature="core"' --cfg 'feature="default"' --cfg 'feature="mem"' -C metadata=a0e694beb56f771f -C extra-filename=-a0e694beb56f771f --out-dir /tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps --target avr-unknown-unknown -L dependency=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps --extern core=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps/librustc_std_workspace_core-1d5b7545d773d921.rmeta --cap-lints allow --cfg 'feature="unstable"'`
   Compiling alloc v0.0.0 (/tmp/xargo.s99JD96fQHru)
     Running `rustc --crate-name alloc --edition=2018 /run/media/jonah/data/Projects/avr-rust/src/liballoc/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C panic=abort -C codegen-units=1 -Z force-unstable-if-unmarked -C metadata=80d3f061118f5dfb -C extra-filename=-80d3f061118f5dfb --out-dir /tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps --target avr-unknown-unknown -L dependency=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps --extern compiler_builtins=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps/libcompiler_builtins-a0e694beb56f771f.rmeta --extern core=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps/libcore-0425a61751752881.rmeta`
LLVM ERROR: Cannot select: 0x7fb3d80431b0: i16 = bitcast 0x7fb3d8076fa0
  0x7fb3d8076fa0: i8,ch,glue = CopyFromReg 0x7fb3d89fefe0:1, Register:i8 $r24, 0x7fb3d89fefe0:2
    0x7fb3d8751e80: i8 = Register $r24
    0x7fb3d89fefe0: i16,ch,glue = CopyFromReg 0x7fb3d83eb7c8:1, Register:i16 $r23r22, 0x7fb3d83eb7c8:2
      0x7fb3d80826c8: i16 = Register $r23r22
      0x7fb3d83eb7c8: i16,ch,glue = CopyFromReg 0x7fb3d8752498, Register:i16 $r21r20, 0x7fb3d8752498:1
        0x7fb3d83ebb08: i16 = Register $r21r20
        0x7fb3d8752498: ch,glue = callseq_end 0x7fb3d8b9c830, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7fb3d8b9c830:1
          0x7fb3d83eb488: i16 = TargetConstant<0>
          0x7fb3d83eb488: i16 = TargetConstant<0>
          0x7fb3d8b9c830: ch,glue = CALL 0x7fb3d83eb558, TargetGlobalAddress:i16<{ i8, i32 } (i32) addrspace(1)* @_ZN4core3num7flt2dec8strategy5grisu22max_pow10_no_more_than17h24eda0bf549557d4E> 0, Register:i16 $r23r22, Register:i16 $r25r24, RegisterMask:Untyped, 0x7fb3d83eb558:1
            0x7fb3d80376c0: i16 = TargetGlobalAddress<{ i8, i32 } (i32) addrspace(1)* @_ZN4core3num7flt2dec8strategy5grisu22max_pow10_no_more_than17h24eda0bf549557d4E> 0
            0x7fb3d80826c8: i16 = Register $r23r22
            0x7fb3d8076a58: i16 = Register $r25r24
            0x7fb3d807eed0: Untyped = RegisterMask
            0x7fb3d83eb558: ch,glue = CopyToReg 0x7fb3d807f140, Register:i16 $r25r24, 0x7fb3d84de068, 0x7fb3d807f140:1
              0x7fb3d8076a58: i16 = Register $r25r24
              0x7fb3d84de068: i16,ch,glue = CopyFromReg 0x7fb3d84de000:1, Register:i16 $r21r20, 0x7fb3d84de000:2
                0x7fb3d83ebb08: i16 = Register $r21r20
                0x7fb3d84de000: i16,ch,glue = CopyFromReg 0x7fb3d84ddf98, Register:i16 $r19r18, 0x7fb3d84ddf98:1
                  0x7fb3d84ddc58: i16 = Register $r19r18
                  0x7fb3d84ddf98: ch,glue = callseq_end 0x7fb3d84ddf30, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7fb3d84ddf30:1



              0x7fb3d807f140: ch,glue = CopyToReg 0x7fb3d8144f70, Register:i16 $r23r22, 0x7fb3d84de000
                0x7fb3d80826c8: i16 = Register $r23r22
                0x7fb3d84de000: i16,ch,glue = CopyFromReg 0x7fb3d84ddf98, Register:i16 $r19r18, 0x7fb3d84ddf98:1
                  0x7fb3d84ddc58: i16 = Register $r19r18
                  0x7fb3d84ddf98: ch,glue = callseq_end 0x7fb3d84ddf30, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7fb3d84ddf30:1



In function: _ZN4core3num7flt2dec8strategy5grisu19format_shortest_opt17hfcc742cc4fb3bf66E
error: could not compile `core`.

Caused by:
  process didn't exit successfully: `rustc --crate-name core --edition=2018 /run/media/jonah/data/Projects/avr-rust/src/libcore/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C panic=abort -C codegen-units=1 -C metadata=0425a61751752881 -C extra-filename=-0425a61751752881 --out-dir /tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps --target avr-unknown-unknown -L dependency=/tmp/xargo.s99JD96fQHru/target/avr-unknown-unknown/release/deps -L dependency=/tmp/xargo.s99JD96fQHru/target/release/deps` (exit code: 101)
warning: build failed, waiting for other jobs to finish...
error: build failed
error: `"/home/jonah/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo" "rustc" "-p" "alloc" "--release" "--manifest-path" "/tmp/xargo.s99JD96fQHru/Cargo.toml" "--target" "avr-unknown-unknown" "-v" "--" "-Z" "force-unstable-if-unmarked"` failed with exit code: Some(101)
note: run with `RUST_BACKTRACE=1` for a backtrace

When I built Rust, I simply edited the config.toml to include the experimental AVR target, and set the prefix. Other than that, I ran ./x.py build && ./x.py install; nothing special.

Is there another commit I should have compiled that can compile core, or something else I did wrong?

[Logarithmus]

I've ran into the same issue, unfortunately. Trying to make my university project in Rust. The deadline approaches rapidly, so most likely I'll just pick C.

[jonahbron]

@Logarithmus Sorry for the delay in seeing this, hope it's not too late. If you use the older more stable avr-support branch, it should compile and work just fine. My understanding is that the master branch is unstable right now because upstream is being merged down into this fork, and not everything has been fixed yet.

[jonahbron]

I have a Gist I put together to go from zero to having a Blink program compiled. Hope this helps.

https://gist.github.com/jonahbron/640a825dd9a526d3a1c24f2c20ca44ac

[Logarithmus]

@jonahbron Thank you for help, but I've figured out it myself short after my previous comment. Now I'm stuck with interrupts.

[Rahix]

@Logarithmus, maybe the code I wrote for avr-device can help here? I have a procedural macro to generate the IRQ definitions which essentially creates this function definition:

#[no_mangle]
pub unsafe extern "avr-interrupt" fn <vector_id>() {
    // ...
}

where <vector_id> is __vector_1, __vector_2, __vector_3, ...

The mapping of IRQ to ID can be found in the datasheet.

[jonahbron]

FYI I gave this another shot today, commit ID 54014d0. Still the same error.

$ XARGO_RUST_SRC="$(realpath ../avr-rust/src)" rustup run avr cargo xbuild --target avr-unknown-unknown --example leonardo-blink
WARNING: There is no root package to read the cargo-xbuild config from.
    Updating crates.io index
  Downloaded compiler_builtins v0.1.28
  Downloaded 1 crate (135.1 KB) in 0.74s
   Compiling core v0.0.0 (/run/media/jonah/data/Projects/avr-rust/src/libcore)
   Compiling compiler_builtins v0.1.28
   Compiling rustc-std-workspace-core v1.99.0 (/run/media/jonah/data/Projects/avr-rust/src/tools/rustc-std-workspace-core)
   Compiling alloc v0.0.0 (/tmp/xargo.cVO5liTsZqc7)
LLVM ERROR: Cannot select: 0x7f66c48f3bc0: i16 = bitcast 0x7f66c46d9e20
  0x7f66c46d9e20: i8,ch,glue = CopyFromReg 0x7f66c4a1b1d0:1, Register:i8 $r24, 0x7f66c4a1b1d0:2
    0x7f66c4073160: i8 = Register $r24
    0x7f66c4a1b1d0: i16,ch,glue = CopyFromReg 0x7f66c4041f08:1, Register:i16 $r23r22, 0x7f66c4041f08:2
      0x7f66c473d1c8: i16 = Register $r23r22
      0x7f66c4041f08: i16,ch,glue = CopyFromReg 0x7f66c4073778, Register:i16 $r21r20, 0x7f66c4073778:1
        0x7f66c4042248: i16 = Register $r21r20
        0x7f66c4073778: ch,glue = callseq_end 0x7f66c40d6890, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7f66c40d6890:1
          0x7f66c4041bc8: i16 = TargetConstant<0>
          0x7f66c4041bc8: i16 = TargetConstant<0>
          0x7f66c40d6890: ch,glue = CALL 0x7f66c4041c98, TargetGlobalAddress:i16<{ i8, i32 } (i32) addrspace(1)* @_ZN4core3num7flt2dec8strategy5grisu22max_pow10_no_more_than17h24eda0bf549557d4E> 0, Register:i16 $r23r22, Register:i16 $r25r24, RegisterMask:Untyped, 0x7f66c4041c98:1
            0x7f66c4da4890: i16 = TargetGlobalAddress<{ i8, i32 } (i32) addrspace(1)* @_ZN4core3num7flt2dec8strategy5grisu22max_pow10_no_more_than17h24eda0bf549557d4E> 0
            0x7f66c473d1c8: i16 = Register $r23r22
            0x7f66c46d98d8: i16 = Register $r25r24
            0x7f66c4951270: Untyped = RegisterMask
            0x7f66c4041c98: ch,glue = CopyToReg 0x7f66c49514e0, Register:i16 $r25r24, 0x7f66c4565a98, 0x7f66c49514e0:1
              0x7f66c46d98d8: i16 = Register $r25r24
              0x7f66c4565a98: i16,ch,glue = CopyFromReg 0x7f66c4565a30:1, Register:i16 $r21r20, 0x7f66c4565a30:2
                0x7f66c4042248: i16 = Register $r21r20
                0x7f66c4565a30: i16,ch,glue = CopyFromReg 0x7f66c45659c8, Register:i16 $r19r18, 0x7f66c45659c8:1
                  0x7f66c4565688: i16 = Register $r19r18
                  0x7f66c45659c8: ch,glue = callseq_end 0x7f66c4565960, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7f66c4565960:1



              0x7f66c49514e0: ch,glue = CopyToReg 0x7f66c40aa9f0, Register:i16 $r23r22, 0x7f66c4565a30
                0x7f66c473d1c8: i16 = Register $r23r22
                0x7f66c4565a30: i16,ch,glue = CopyFromReg 0x7f66c45659c8, Register:i16 $r19r18, 0x7f66c45659c8:1
                  0x7f66c4565688: i16 = Register $r19r18
                  0x7f66c45659c8: ch,glue = callseq_end 0x7f66c4565960, TargetConstant:i16<0>, TargetConstant:i16<0>, 0x7f66c4565960:1



In function: _ZN4core3num7flt2dec8strategy5grisu19format_shortest_opt17hfcc742cc4fb3bf66E
error: could not compile `core`.

To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
error: `"/home/jonah/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/bin/cargo" "rustc" "-p" "alloc" "--release" "--manifest-path" "/tmp/xargo.cVO5liTsZqc7/Cargo.toml" "--target" "avr-unknown-unknown" "--" "-Z" "force-unstable-if-unmarked"` failed with exit code: Some(101)
note: run with `RUST_BACKTRACE=1` for a backtrace