wasm link failures - "The end of the file was unexpectedly encountered"

[lilyball]

With the release of Rust 1.14.0, I wanted to try out the emscripten support. I've never used emscripten before, so here's the steps I took:

> brew install emscripten
# installing
# brew instructed me to edit ~/.emscripten
> vim ~/.emscripten # edit as instructed
> rustup target add wasm32-unknown-emscripten
> echo 'fn main() { println!("Hello, Emscripten!"); }' > hello.rs
> rustc --target=wasm32-unknown-emscripten hello.rs

At this point, emcc spewed a bunch of link errors:

error: linking with `emcc` failed: exit code: 1
  |
  = note: "emcc" "-L" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib" "hello.0.o" "-o" "hello.js" "-Wl,--gc-sections" "-nodefaultlibs" "-L" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib" "-Wl,-Bstatic" "-Wl,-Bdynamic" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libstd-610aec1c0c2edd5b.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libpanic_unwind-f2d5dd75c5a64c5f.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libunwind-cce8009dda26867d.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/librand-d2f56491199d3b9f.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcollections-4f02fd86535a3157.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/librustc_unicode-8d6c34ad46f07f91.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liballoc-198f48436646c796.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liballoc_system-22e63f2ceba0e6f8.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liblibc-9b19cb4b417215a8.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcore-ec0461203eec19c8.rlib" "/Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcompiler_builtins-ad8606f391af463e.rlib" "-l" "c" "-s" "BINARYEN=1" "-s" "ERROR_ON_UNDEFINED_SYMBOLS=1"
  = note: /usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libstd-610aec1c0c2edd5b.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libpanic_unwind-f2d5dd75c5a64c5f.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libunwind-cce8009dda26867d.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/librand-d2f56491199d3b9f.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcollections-4f02fd86535a3157.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/librustc_unicode-8d6c34ad46f07f91.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liballoc-198f48436646c796.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liballoc_system-22e63f2ceba0e6f8.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/liblibc-9b19cb4b417215a8.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcore-ec0461203eec19c8.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

/usr/local/opt/emscripten/libexec/llvm/bin/llvm-nm: /Users/kevinballard/.rustup/toolchains/stable-x86_64-apple-darwin/lib/rustlib/wasm32-unknown-emscripten/lib/libcompiler_builtins-ad8606f391af463e.rlib(rust.metadata.bin) The end of the file was unexpectedly encountered

Traceback (most recent call last):
  File "/usr/local/bin/emcc", line 13, in <module>
    emcc.run()
  File "/usr/local/Cellar/emscripten/1.36.14/libexec/emcc.py", line 1609, in run
    wasm_js_glue = open(os.path.join(shared.Settings.BINARYEN_ROOT, 'src', 'js', 'wasm.js-post.js')).read()
IOError: [Errno 2] No such file or directory: u'/usr/bin/src/js/wasm.js-post.js'

This is on macOS 10.12.2, Rust 1.14.0, and emscripten 1.36.14.

[brson]

Thanks for the report @kballard. I intend to make a sweep through all the emscripten issues soon and try to make some fresh progress.

[brson]

Same as the secondary issue in #37185

[wehlutyk]

I'm seeing the same issue on an up-to-date ArchLinux, with Rust 1.14.0 and Emscripten 1.37.1 (following the same steps). The asm.js build works fine though.

[mckinnsb]

Also seeing what @wehlutyk reported on Ubuntu 16 on nightly.

In this case, it only happens when I build for release, but the debug build fails regardless ( with error: "Uncaught no binaryen method succeeded. consider enabling more options, like interpreting, if you want that: " ).

[brson]

Thanks for the additional reports @wehlutyk @mckinnsb . I've updated the title to indicate it's multiplatform.

[donhcd]

on OSX 10.11.5, rustc 1.17.0-nightly (956e2bc 2017-02-12), emcc 1.36.11 (commit c5af8f63f00bb03aa2177c71d16628474918b60f), I get a similar but slightly different error if I compile with target wasm and with the --release flag.

It works perfectly if I leave out the --release flag.

[CryZe]

This is a "duplicate" of this issue: WebAssembly/binaryen#855

Pretty sure this is due to the vector instructions that rustc emits. This should happen a lot more with the recent changes @RReverser introduced, since --release now actually produces vector instructions, which it didn't before, because --release didn't actually run any optimizations.

[RReverser]

@CryZe --release did still run Rust / LLVM optimizations before, the only difference is that it now also asks Emscripten to run JS-specific optimizations. If, as it sounds from the description, the error is on Rust side emitting unsupported instructions (and not Emscripten's), then nothing should have changed compared to previous state.