Failed to get bitcode from object file for LTO

[jiayihu]

When trying to use the tool I get the following error:

cargo +nightly call-stack --bin fedra --verbose

"cargo" "rustc" "--bin" "fedra" "--release" "--" "--emit=llvm-ir,obj" "-C" "embed-bitcode=yes" "-C" "lto=fat" "-Z" "emit-stack-sizes"
   Compiling fedra v0.1.0 (/Users/jiayihu/Desktop/Repo/fedra-clone)
error: failed to get bitcode from object file for LTO (Bitcode section not found in object file)

rustc --version
rustc 1.50.0-nightly (593fe977a 2020-11-20)

Same error even with the previous nightly rustc 1.49.0-nightly (b1496c6e6 2020-10-18)

[jiayihu]

Ironically if I try RUSTFLAGS="-C embed-bitcode" as said in #25 , it gives a different error:

error: BUG: failed to parse .ll file; please submit a bug report with Rust source code. Details (include the _first_ LLVM item, e.g. `define .. { .. }`, in the report):
Failure(("%0 = type { [0 x i32], { {}*, [3 x i32]* }, [0 x i32], i8*, [0 x i32] }\n%1 = type { [0 x i32], %2, [0 x i32], i8*, [0 x i8], i8, [3 x i8] }\n%2 = type { [0 x i32], %\"rtt_target::rtt::RttChannel\"*, [0 x i32], i32, [0 x i32], i32, [0 x i8], i8, [3 x i8] }\n%3 = type { [0 x i32], %\"alloc::string::String\", [0 x i32] }\n%4 = type { [0 x i32], %\"core::fmt::Formatter\"*, [0 x i32], i32, [0 x i8], i8, [0 x i8], i8, [2 x i8] }\n%5 = type { [0 x i32], %\"core::fmt::Formatter\"*, [0 x i8], i8, [0 x i8], i8, [2 x i8] }\n%6 = type { [0 x i8], i8, [11 x i8] }\n%7 = type { [0 x i32], %8, [0 x i32], i32, [0 x i32] }\n%8 = type { [0 x i32], %9, [0 x i32], %9, [0 x i32] }\n%9 = type { [1 x i32], {}*, [1 x i32] }\n%10 = type { [0 x i8], {}, [0 x i8], i32*, [0 x i32], i32*, [0 x i32], i32, [0 x i32] }\n%11 = type { [0 x i32], %\"smoltcp::wire::Icmpv4Repr\", [0 x i32] }\n%12 = type { [0 x i32], i32, [0 x i32], i32, [0 x i32], %13, [0 x i32] }\n%13 = type { [0 x i32], %\"parity_wasm::el
[...]

[CedMaire]

Any update on fixing this issue?

[ysun]

I got the same issue. May I know the progress of this issue ? I got exactly the same issue with @jiayihu. Hi @jiayihu do you get the solution ?

[jiayihu]

Sorry @ysun, no luck

[ysun]

@jiayihu Then did you get any other solution to get rust call-graph ?

[taqtiqa-mark]

We have also observed this error:

BUG: failed to parse .ll file: Failure(("define internal fastcc void @_Z....

The following is a MRE.

Run this command:

RUSTFLAGS = "-C embed-bitcode" cargo +nightly call-stack --example rme > mre.dot

With this code as examples/mre.rs:

use lazy_static::lazy_static;
use rand::distributions::{Distribution, Uniform};
use std::time::Duration;
use tokio::time::{sleep, Instant};

lazy_static! { static ref START_TIME: Instant = Instant::now(); }

#[tokio::main]
async fn main() {
    let page = get_page(42).await;
    println!("Page #42: {:?}", page);
}

async fn get_page(i: usize) -> Vec<usize> {
    let millis = Uniform::from(5_000..6_000).sample(&mut rand::thread_rng());
    println!( "[{}] # get_page({}) will complete in {} ms on {:?}",
        START_TIME.elapsed().as_millis(),
        i,
        millis,
        std::thread::current().id()
    );

    sleep(Duration::from_millis(millis)).await;
    println!("[{}] # get_page({}) completed",
        START_TIME.elapsed().as_millis(),
        i
    );
    (10 * i..10 * (i + 1)).collect()
}

[savchenko]

Observing the same on the "hello world" created via cargo new.

cargo +nightly call-stack --bin hello --target x86_64-unknown-linux-gnu > hello.dot

1. Exporting RUSTFLAGS="-C embed-bitcode" results in:

   error: failed to parse application's LLVM IR from `/tst/helloworld/target/x86_64-unknown-linux-gnu/release/deps/hello-f16df3c84b67da29.ll`: BUG: failed to parse LLVM IR; please submit a cargo-call-stack bug report and attach the `.ll` file: Failure("Eof in line 970")
   

   .ll file is attached to this message: hello-ll.zip

2. Using LTO leads to the same problem.

3. Not using either yields the error:

   error: failed to get bitcode from object file for LTO (Bitcode section not found in object file)
   

@jiayihu , looks suspiciously similar to what @taqtiqa-mark is experiencing in #33

[japaric]

This issue seems to only affect Cargo project using the default release profile. To get pass the "Bitcode section not found in object file" error enable fat LTO in Cargo.toml -- this is a workaround

[profile.release]
lto = 'fat'

A fix may be adding -C embed-bitcode=yes to each rustc invocation; either that or remove the -C embed-bitcode=no that gets passed to rustc by default (when lto = 'thin').

after enabling fat LTO I get a LLVM IR parser error when running cargo-call-stack on a "Hello, world" project but that's a separate issue from this.