This patch adds 2 functions for the runtime C API, respectively
`wasmer_instance_context_data_set` and
`wasmer_instance_context_data_get`. The goal is to modify the
`vm::Ctx.data` field in the `runtime-core` library.
This is required to pass dynamic data to imported functions for
instance.
This patch ensures that all our examples and tests do not generate
warnings. In C, it can be catastrophic sometimes…
Also, be sure that the `cmake` command doesn't emit any warnings too.
When compiling `wasmer-runtime-c-api` as a dependency of another
crate, `rustc` emits this warning:
```
warning: The package `wasmer_runtime_c_api` provides no linkable
target. The compiler might raise an error while compiling
`foo`. Consider adding 'dylib' or 'rlib' to key `crate-type` in
`wasmer_runtime_c_api`'s Cargo.toml. This warning might turn into a
hard error in the future.
```
To solve this issue, the `rlib` type has been added to the
`crate-type` list.
This patch removes the `WASM_EMSCRIPTEN_GENERATE_C_API_HEADERS`
flag. Consequently, the C header files will be generated for each
build.
The `generate-c-api-headers` feature is also removed, since it becomes useless.
This patch changes the directory where the C header files are
generated, from `CARGO_MANIFEST_DIR` to `OUT_DIR`. The goal is: When
`wasm-runtime-c-api` is used as a dependency of another Rust project,
then the C header files are accessible in the `target/` directory
(i.e. the `OUT_DIR`).
Also, since `rustc` has a `--out-dir` directory, it increases the
flexibility of this approach: The user can generate the C header files
where she wants.
When requiring `wasmer-runtime-c-api`, I get the following conflicts:
```
error: failed to select a version for `serde_derive`.
... required by package `cbindgen v0.7.1`
... which is depended on by `wasmer-runtime-c-api v0.2.1`
... which is depended on by `foo v0.1.0 (/private/tmp/foo)`
versions that meet the requirements `= 1.0.58` are: 1.0.58
all possible versions conflict with previously selected packages.
previously selected package `serde_derive v1.0.89`
... which is depended on by `wasmer-runtime-core v0.2.1`
... which is depended on by `wasmer-runtime-c-api v0.2.1`
... which is depended on by `foo v0.1.0 (/private/tmp/foo)`
failed to select a version for `serde_derive` which could resolve this conflict
```
This issue resolves by updating `cbindgen` to 0.8.
This patch cleans several warnings where mutable bindings are declared
but used only as immutable bindings.
It's a little bit opinionated patch. I think it's interesting to use
`const` pointers as much as possible.
This patch removes `unsafe { … }` blocks inside `unsafe` functions.
This patch also removes some warnings about camel case. All structures
with a C representation are automatically not mangle, and allow non
camel case.
