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Auto-generate the hostcalls module of wasi-common (#846)

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* Auto-generate shims for old `wasi_unstable` module

This commit is effectively just doing what #707 already did, but
applying it to the `snapshot_0` module as well. The end result is the
same, where we cut down on all the boilerplate in `snapshot_0` and bring
it in line with the main `wasi_snapshot_preview1` implementation. The
goal here is to make it easier to change the two in tandem since they're
both doing the same thing.

* Migrate `wasi_common::hostcalls` to a macro

This commit migrates the `hostcalls` module to being auto-generated by a
macro rather than duplicating a handwritten signature for each wasi
syscall.

* Auto-generate snapshot_0's `hostcalls` module

Similar to the previous commit, but for `snapshot_0`

* Delete the `wasi-common-cbindgen` crate

This is no longer needed with the hostcalls macro now, we can easily
fold the definition of the cbindgen macro into the same crate.

* Rustfmt

* Fix windows build errors

* Rustfmt

* Remove now no-longer-necessary code

* rustfmt
This commit is contained in:
Alex Crichton
2020-01-22 14:54:39 -06:00
committed by GitHub
parent 5d7635c351
commit 5953215bac
44 changed files with 391 additions and 2742 deletions
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131
crates/wasi-common/wig/src/hostcalls.rs Normal file
View File

@@ -0,0 +1,131 @@
use crate::utils;
use proc_macro2::TokenStream;
use quote::{format_ident, quote};
pub fn define(args: TokenStream) -> TokenStream {
let (path, phase) = utils::witx_path_from_args(args);
let doc = match witx::load(&[&path]) {
Ok(doc) => doc,
Err(e) => {
panic!("error opening file {}: {}", path, e);
}
};
let mut ret = TokenStream::new();
let old = match phase.as_str() {
"snapshot" => false,
"old/snapshot_0" => true,
s => panic!("unsupported phase: {}", s),
};
for module in doc.modules() {
for func in module.funcs() {
ret.extend(generate_wrappers(&func, old));
}
}
return ret;
}
fn generate_wrappers(func: &witx::InterfaceFunc, old: bool) -> TokenStream {
let name = format_ident!("{}", func.name.as_str());
let mut arg_declarations = Vec::new();
let mut arg_names = Vec::new();
for param in func.params.iter() {
let name = utils::param_name(param);
if let witx::TypePassedBy::PointerLengthPair = param.tref.type_().passed_by() {
let ptr = format_ident!("{}_ptr", name);
let len = format_ident!("{}_len", name);
arg_declarations.push(quote! { #ptr: super::wasi32::uintptr_t });
arg_declarations.push(quote! { #len: super::wasi32::size_t });
arg_names.push(ptr);
arg_names.push(len);
continue;
}
match &param.tref {
witx::TypeRef::Name(n) => {
if n.name.as_str() == "size" {
arg_declarations.push(quote! { #name: super::wasi32::size_t });
} else {
let ty_name = format_ident!("__wasi_{}_t", n.name.as_str());
arg_declarations.push(quote! { #name: super::wasi::#ty_name });
}
}
witx::TypeRef::Value(v) => match &**v {
witx::Type::ConstPointer(_) | witx::Type::Pointer(_) => {
arg_declarations.push(quote! { #name: super::wasi32::uintptr_t });
}
_ => panic!("unexpected value type"),
},
}
arg_names.push(name);
}
let mut ret = quote!(());
for (i, result) in func.results.iter().enumerate() {
if i == 0 {
match &result.tref {
witx::TypeRef::Name(n) => {
let ty_name = format_ident!("__wasi_{}_t", n.name.as_str());
ret = quote! { super::wasi::#ty_name };
}
witx::TypeRef::Value(_) => panic!("unexpected value type"),
}
continue;
}
let name = utils::param_name(result);
arg_declarations.push(quote! { #name: super::wasi32::uintptr_t });
arg_names.push(name);
}
let call = quote! {
super::hostcalls_impl::#name(wasi_ctx, memory, #(#arg_names,)*)
};
let body = if func.results.len() == 0 {
call
} else {
quote! {
let ret = #call
.err()
.unwrap_or(super::Error::ESUCCESS)
.as_wasi_error();
log::trace!(" | errno={}", ret);
ret.as_raw_errno()
}
};
let c_abi_name = if old {
format_ident!("old_wasi_common_{}", name)
} else {
format_ident!("wasi_common_{}", name)
};
quote! {
pub unsafe fn #name(
wasi_ctx: &mut super::WasiCtx,
memory: &mut [u8],
#(#arg_declarations,)*
) -> #ret {
#body
}
#[no_mangle]
pub unsafe fn #c_abi_name(
wasi_ctx: *mut super::WasiCtx,
memory: *mut u8,
memory_len: usize,
#(#arg_declarations,)*
) -> #ret {
#name(
&mut *wasi_ctx,
std::slice::from_raw_parts_mut(memory, memory_len),
#(#arg_names,)*
)
}
}
}

6
crates/wasi-common/wig/src/lib.rs
View File

@@ -1,5 +1,6 @@
extern crate proc_macro;
mod hostcalls;
mod raw_types;
mod utils;
mod wasi;
@@ -36,3 +37,8 @@ pub fn witx_wasi32_types(args: TokenStream) -> TokenStream {
pub fn define_add_wrappers_to_module(args: TokenStream) -> TokenStream {
wasi::add_wrappers_to_module(args.into()).into()
}
#[proc_macro]
pub fn define_hostcalls(args: TokenStream) -> TokenStream {
hostcalls::define(args.into()).into()
}

17
crates/wasi-common/wig/src/raw_types.rs
View File

@@ -50,12 +50,13 @@ fn gen_datatypes(output: &mut TokenStream, doc: &witx::Document, mode: Mode) {
fn gen_datatype(output: &mut TokenStream, mode: Mode, namedtype: &witx::NamedType) {
let wasi_name = format_ident!("__wasi_{}_t", namedtype.name.as_str());
match &namedtype.dt {
match &namedtype.tref {
witx::TypeRef::Name(alias_to) => {
let to = tref_tokens(mode, &alias_to.dt);
let to = tref_tokens(mode, &alias_to.tref);
output.extend(quote!(pub type #wasi_name = #to;));
}
witx::TypeRef::Value(v) => match &**v {
witx::Type::Int(_) => panic!("unsupported int datatype"),
witx::Type::Enum(e) => {
let repr = int_repr_tokens(e.repr);
output.extend(quote!(pub type #wasi_name = #repr;));
@@ -143,7 +144,7 @@ fn gen_datatype(output: &mut TokenStream, mode: Mode, namedtype: &witx::NamedTyp
witx::Type::Pointer { .. }
| witx::Type::ConstPointer { .. }
| witx::Type::Array { .. } => {
let tref_tokens = tref_tokens(mode, &namedtype.dt);
let tref_tokens = tref_tokens(mode, &namedtype.tref);
output.extend(quote!(pub type #wasi_name = #tref_tokens;));
}
},
@@ -156,7 +157,7 @@ fn gen_datatype(output: &mut TokenStream, mode: Mode, namedtype: &witx::NamedTyp
}
fn gen_errno_strerror(output: &mut TokenStream, namedtype: &witx::NamedType) {
let inner = match &namedtype.dt {
let inner = match &namedtype.tref {
witx::TypeRef::Value(v) => match &**v {
witx::Type::Enum(e) => e,
x => panic!("expected Enum('errno'), instead received {:?}", x),
@@ -198,6 +199,7 @@ fn builtin_tokens(mode: Mode, builtin: witx::BuiltinType) -> TokenStream {
Mode::Wasi => panic!("strings have target-specific size"),
Mode::Wasi32 => quote!((u32, u32)),
},
witx::BuiltinType::Char8 => quote!(i8),
witx::BuiltinType::U8 => quote!(u8),
witx::BuiltinType::U16 => quote!(u16),
witx::BuiltinType::U32 => quote!(u32),
@@ -208,6 +210,11 @@ fn builtin_tokens(mode: Mode, builtin: witx::BuiltinType) -> TokenStream {
witx::BuiltinType::S64 => quote!(i64),
witx::BuiltinType::F32 => quote!(f32),
witx::BuiltinType::F64 => quote!(f64),
witx::BuiltinType::USize => match mode {
Mode::Host => quote!(usize),
Mode::Wasi => panic!("usize has target-specific size"),
Mode::Wasi32 => quote!(u32),
},
}
}
@@ -270,7 +277,7 @@ fn namedtype_has_target_size(nt: &witx::NamedType) -> bool {
if nt.name.as_str() == "size" {
true
} else {
tref_has_target_size(&nt.dt)
tref_has_target_size(&nt.tref)
}
}

12
crates/wasi-common/wig/src/utils.rs
View File

@@ -1,4 +1,4 @@
use proc_macro2::{Literal, TokenStream, TokenTree};
use proc_macro2::{Ident, Literal, TokenStream, TokenTree};
/// Given the input tokens to a macro invocation, return the path to the
/// witx file to process.
@@ -53,3 +53,13 @@ fn parse_string_literal(literal: Literal) -> String {
trimmed
}
pub fn param_name(param: &witx::InterfaceFuncParam) -> Ident {
quote::format_ident!(
"{}",
match param.name.as_str() {
"in" | "type" => format!("r#{}", param.name.as_str()),
s => s.to_string(),
}
)
}

21
crates/wasi-common/wig/src/wasi.rs
View File

@@ -45,13 +45,7 @@ pub fn add_wrappers_to_module(args: TokenStream) -> TokenStream {
let mut hostcall_args = Vec::new();
for param in func.params.iter() {
let name = format_ident!(
"{}",
match param.name.as_str() {
"in" | "type" => format!("r#{}", param.name.as_str()),
s => s.to_string(),
}
);
let name = utils::param_name(param);
// Registers a new parameter to the shim we're making with the
// given `name`, the `abi_ty` wasm type and `hex` defines
@@ -89,6 +83,11 @@ pub fn add_wrappers_to_module(args: TokenStream) -> TokenStream {
};
match &*param.tref.type_() {
witx::Type::Int(e) => match e.repr {
witx::IntRepr::U64 => add_param(&name, Abi::I64, false),
_ => add_param(&name, Abi::I32, false),
},
witx::Type::Enum(e) => match e.repr {
witx::IntRepr::U64 => add_param(&name, Abi::I64, false),
_ => add_param(&name, Abi::I32, false),
@@ -99,12 +98,14 @@ pub fn add_wrappers_to_module(args: TokenStream) -> TokenStream {
_ => add_param(&name, Abi::I32, true),
},
witx::Type::Builtin(witx::BuiltinType::S8)
witx::Type::Builtin(witx::BuiltinType::Char8)
| witx::Type::Builtin(witx::BuiltinType::S8)
| witx::Type::Builtin(witx::BuiltinType::U8)
| witx::Type::Builtin(witx::BuiltinType::S16)
| witx::Type::Builtin(witx::BuiltinType::U16)
| witx::Type::Builtin(witx::BuiltinType::S32)
| witx::Type::Builtin(witx::BuiltinType::U32) => {
| witx::Type::Builtin(witx::BuiltinType::U32)
| witx::Type::Builtin(witx::BuiltinType::USize) => {
add_param(&name, Abi::I32, false);
}
@@ -208,7 +209,7 @@ pub fn add_wrappers_to_module(args: TokenStream) -> TokenStream {
Ok(e) => e,
Err(e) => #handle_early_error,
};
wasi_common::hostcalls::#name_ident(
hostcalls::#name_ident(
wasi_ctx,
memory,
#(#hostcall_args),*