fails to compile to wasm

[ulrichard]

$ wasm-pack build --target web
[INFO]: Checking for the Wasm target...
[INFO]: Compiling to Wasm...
   Compiling bitcoinconsensus v0.19.0-3
The following warnings were emitted during compilation:

warning: error: invalid argument '-std=c++11' not allowed with 'C'

error: failed to run custom build command for `bitcoinconsensus v0.19.0-3`

Caused by:
  process didn't exit successfully: `/home/richi/sourcecode/seba/github/bdk-reserves-web/target/release/build/bitcoinconsensus-438c8c5f1d9ce627/build-script-build` (exit status: 1)
  --- stdout
  OPT_LEVEL = Some("3")
  TARGET = Some("wasm32-unknown-unknown")
  HOST = Some("x86_64-unknown-linux-gnu")
  CXX_wasm32-unknown-unknown = None
  CXX_wasm32_unknown_unknown = None
  TARGET_CXX = None
  CXX = None
  CXXFLAGS_wasm32-unknown-unknown = None
  CXXFLAGS_wasm32_unknown_unknown = None
  TARGET_CXXFLAGS = None
  CXXFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("false")
  CXX_wasm32-unknown-unknown = None
  CXX_wasm32_unknown_unknown = None
  TARGET_CXX = None
  CXX = None
  CXXFLAGS_wasm32-unknown-unknown = None
  CXXFLAGS_wasm32_unknown_unknown = None
  TARGET_CXXFLAGS = None
  CXXFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  running: "clang" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=wasm32-unknown-unknown" "-I" "depend/bitcoin/src" "-I" "depend/bitcoin/src/secp256k1/include" "-I" "depend/bitcoin/src/secp256k1" "-Wall" "-Wextra" "-std=c++11" "-Wno-unused-parameter" "-D__STDC_FORMAT_MACROS" "-DSECP256K1_BUILD=1" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DENABLE_MODULE_RECOVERY=1" "-DUSE_FIELD_10X26=1" "-DUSE_SCALAR_8X32=1" "-o" "/home/richi/sourcecode/seba/github/bdk-reserves-web/target/wasm32-unknown-unknown/release/build/bitcoinconsensus-8310f8dedcb0d87a/out/depend/bitcoin/src/secp256k1/src/secp256k1.o" "-c" "depend/bitcoin/src/secp256k1/src/secp256k1.c"
  cargo:warning=error: invalid argument '-std=c++11' not allowed with 'C'
  exit status: 1

  --- stderr


  error occurred: Command "clang" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "--target=wasm32-unknown-unknown" "-I" "depend/bitcoin/src" "-I" "depend/bitcoin/src/secp256k1/include" "-I" "depend/bitcoin/src/secp256k1" "-Wall" "-Wextra" "-std=c++11" "-Wno-unused-parameter" "-D__STDC_FORMAT_MACROS" "-DSECP256K1_BUILD=1" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DENABLE_MODULE_RECOVERY=1" "-DUSE_FIELD_10X26=1" "-DUSE_SCALAR_8X32=1" "-o" "/home/richi/sourcecode/seba/github/bdk-reserves-web/target/wasm32-unknown-unknown/release/build/bitcoinconsensus-8310f8dedcb0d87a/out/depend/bitcoin/src/secp256k1/src/secp256k1.o" "-c" "depend/bitcoin/src/secp256k1/src/secp256k1.c" with args "clang" did not execute successfully (status code exit status: 1).


Error: Compiling your crate to WebAssembly failed
Caused by: failed to execute `cargo build`: exited with exit status: 101
  full command: "cargo" "build" "--lib" "--release" "--target" "wasm32-unknown-unknown"
make: *** [Makefile:3: build] Fehler 1

Shell beendet 2

[TheBlueMatt]

This sounds like a bug in cc - it should be building as C++ not C.

[tcharding]

Hi @ulrichard, are you still hitting this issue?

[sebastianmontero]

Hi I'm getting this issue when compliling to wasm:

error: failed to run custom build command for `bitcoinconsensus v0.20.2-0.5.0`

Caused by:
  process didn't exit successfully: `/home/sebastian/vsc-workspace/coinstr-wasm/target/debug/build/bitcoinconsensus-3fe2c1af365d97c8/build-script-build` (exit status: 1)
  --- stdout
  OPT_LEVEL = Some("0")
  TARGET = Some("wasm32-unknown-unknown")
  HOST = Some("x86_64-unknown-linux-gnu")
  cargo:rerun-if-env-changed=CXX_wasm32-unknown-unknown
  CXX_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CXX_wasm32_unknown_unknown
  CXX_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CXX
  TARGET_CXX = None
  cargo:rerun-if-env-changed=CXX
  CXX = None
  cargo:rerun-if-env-changed=CXXFLAGS_wasm32-unknown-unknown
  CXXFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CXXFLAGS_wasm32_unknown_unknown
  CXXFLAGS_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CXXFLAGS
  TARGET_CXXFLAGS = None
  cargo:rerun-if-env-changed=CXXFLAGS
  CXXFLAGS = None
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  cargo:rerun-if-env-changed=CXX_wasm32-unknown-unknown
  CXX_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CXX_wasm32_unknown_unknown
  CXX_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CXX
  TARGET_CXX = None
  cargo:rerun-if-env-changed=CXX
  CXX = None
  cargo:rerun-if-env-changed=CXXFLAGS_wasm32-unknown-unknown
  CXXFLAGS_wasm32-unknown-unknown = None
  cargo:rerun-if-env-changed=CXXFLAGS_wasm32_unknown_unknown
  CXXFLAGS_wasm32_unknown_unknown = None
  cargo:rerun-if-env-changed=TARGET_CXXFLAGS
  TARGET_CXXFLAGS = None
  cargo:rerun-if-env-changed=CXXFLAGS
  CXXFLAGS = None
  cargo:rerun-if-env-changed=CRATE_CC_NO_DEFAULTS
  CRATE_CC_NO_DEFAULTS = None
  running: "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=wasm32-unknown-unknown" "-I" "depend/bitcoin/src" "-I" "depend/bitcoin/src/secp256k1/include" "-I" "depend/bitcoin/src/secp256k1" "-Wall" "-Wextra" "-std=c++11" "-Wno-unused-parameter" "-D__STDC_FORMAT_MACROS" "-DSECP256K1_BUILD=1" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DENABLE_MODULE_RECOVERY=1" "-DUSE_FIELD_10X26=1" "-DUSE_SCALAR_8X32=1" "-o" "/home/sebastian/vsc-workspace/coinstr-wasm/target/wasm32-unknown-unknown/debug/build/bitcoinconsensus-e49a0edf6d52a536/out/depend/bitcoin/src/secp256k1/src/secp256k1.o" "-c" "depend/bitcoin/src/secp256k1/src/secp256k1.c"
  cargo:warning=error: invalid argument '-std=c++11' not allowed with 'C'
  exit status: 1

  --- stderr


  error occurred: Command "clang" "-O0" "-ffunction-sections" "-fdata-sections" "-fPIC" "-g" "-fno-omit-frame-pointer" "--target=wasm32-unknown-unknown" "-I" "depend/bitcoin/src" "-I" "depend/bitcoin/src/secp256k1/include" "-I" "depend/bitcoin/src/secp256k1" "-Wall" "-Wextra" "-std=c++11" "-Wno-unused-parameter" "-D__STDC_FORMAT_MACROS" "-DSECP256K1_BUILD=1" "-DUSE_NUM_NONE=1" "-DUSE_FIELD_INV_BUILTIN=1" "-DUSE_SCALAR_INV_BUILTIN=1" "-DENABLE_MODULE_RECOVERY=1" "-DUSE_FIELD_10X26=1" "-DUSE_SCALAR_8X32=1" "-o" "/home/sebastian/vsc-workspace/coinstr-wasm/target/wasm32-unknown-unknown/debug/build/bitcoinconsensus-e49a0edf6d52a536/out/depend/bitcoin/src/secp256k1/src/secp256k1.o" "-c" "depend/bitcoin/src/secp256k1/src/secp256k1.c" with args "clang" did not execute successfully (status code exit status: 1).

Do you know what might be the cause?

@ulrichard did you manage to solve your issue?

[ulrichard]

I still get the same error as above with the current master.
It is not important to me TBH. It would have been cool to integrate it in a website, but not essential for me.
I guess that's easier with pure rust stuff.

[TheBlueMatt]

Note that in general you cannot safely link most C code with wasm_bindegn. While we should fix this, you'll need to use a different wasm build target to make it work.

[ssantos21]

I am getting the same error with wasm-pack build --release --target web.

warning: error: invalid argument '-std=c++11' not allowed with 'C'

error: failed to run custom build command for `bitcoinconsensus v0.20.2-0.5.0`

@TheBlueMatt Could you elaborate? Is there a way to make this library work with wasm-pack build ?

[ulrichard]

I started experimenting:
https://github.com/AminaBank/rust-bitcoinconsensus/tree/feature/wasm
But so far, it doesn't look too good.

[tcharding]

I had a brief look and I rekon that the problem is the secp build, which requires various things like patching out functions etc. I'd say we have to port all the wasm build stuff from secp256k1 to this repo. At a very minimum.

[apoelstra]

I wonder if we can patch out libsecp entirely and link against the one in rust-secp-sys. We would like to do this anyway to minimize the amount of code we compile.

[TheBlueMatt]

I'm confused why we think this is related to secp - the specific error (passing a C++ argument when building targeting C) sounds like either we're invoking cc wrong (which I doubt, cause it works for non-wasm) or cc is buggy building C++ for wasm, which needs to be fixed in the cc crate.

[tcharding]

I'm confused why we think this is related to secp

By "related to secp" I meant I messed around with the build file and could not get secp to build, and that is the first step before building the C++ code.

I got past the exact error in this issue.

[TheBlueMatt]

Ah, so somehow we shouldn't be passing the std=c++... argument in the secp builds? I assume we'll just hit this error eventually once we get to C++ files though.

[tcharding]

Adding this to C++ builds and not to C builds seems to fix this specific error.

    config.cpp(true)

EDIT: I am not totally confident in this statement.

[ulrichard]

What is the reason that compiling for wasm in rust-secp256k1 is patching the Cargo.toml file just for the test? Would that modification break anything else if applied permanently?
I don't think in this state, it could be used as a direct dependency.