diff options
Diffstat (limited to '')
-rw-r--r-- | compiler/rustc_target/src/abi/call/wasm.rs | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/compiler/rustc_target/src/abi/call/wasm.rs b/compiler/rustc_target/src/abi/call/wasm.rs new file mode 100644 index 000000000..3237cde10 --- /dev/null +++ b/compiler/rustc_target/src/abi/call/wasm.rs @@ -0,0 +1,83 @@ +use crate::abi::call::{ArgAbi, FnAbi, Uniform}; +use crate::abi::{HasDataLayout, TyAbiInterface}; + +fn unwrap_trivial_aggregate<'a, Ty, C>(cx: &C, val: &mut ArgAbi<'a, Ty>) -> bool +where + Ty: TyAbiInterface<'a, C> + Copy, + C: HasDataLayout, +{ + if val.layout.is_aggregate() { + if let Some(unit) = val.layout.homogeneous_aggregate(cx).ok().and_then(|ha| ha.unit()) { + let size = val.layout.size; + if unit.size == size { + val.cast_to(Uniform { unit, total: size }); + return true; + } + } + } + false +} + +fn classify_ret<'a, Ty, C>(cx: &C, ret: &mut ArgAbi<'a, Ty>) +where + Ty: TyAbiInterface<'a, C> + Copy, + C: HasDataLayout, +{ + ret.extend_integer_width_to(32); + if ret.layout.is_aggregate() && !unwrap_trivial_aggregate(cx, ret) { + ret.make_indirect(); + } +} + +fn classify_arg<'a, Ty, C>(cx: &C, arg: &mut ArgAbi<'a, Ty>) +where + Ty: TyAbiInterface<'a, C> + Copy, + C: HasDataLayout, +{ + arg.extend_integer_width_to(32); + if arg.layout.is_aggregate() && !unwrap_trivial_aggregate(cx, arg) { + arg.make_indirect_byval(); + } +} + +/// The purpose of this ABI is to match the C ABI (aka clang) exactly. +pub fn compute_c_abi_info<'a, Ty, C>(cx: &C, fn_abi: &mut FnAbi<'a, Ty>) +where + Ty: TyAbiInterface<'a, C> + Copy, + C: HasDataLayout, +{ + if !fn_abi.ret.is_ignore() { + classify_ret(cx, &mut fn_abi.ret); + } + + for arg in &mut fn_abi.args { + if arg.is_ignore() { + continue; + } + classify_arg(cx, arg); + } +} + +/// The purpose of this ABI is for matching the WebAssembly standard. This +/// intentionally diverges from the C ABI and is specifically crafted to take +/// advantage of LLVM's support of multiple returns in WebAssembly. +pub fn compute_wasm_abi_info<Ty>(fn_abi: &mut FnAbi<'_, Ty>) { + if !fn_abi.ret.is_ignore() { + classify_ret(&mut fn_abi.ret); + } + + for arg in &mut fn_abi.args { + if arg.is_ignore() { + continue; + } + classify_arg(arg); + } + + fn classify_ret<Ty>(ret: &mut ArgAbi<'_, Ty>) { + ret.extend_integer_width_to(32); + } + + fn classify_arg<Ty>(arg: &mut ArgAbi<'_, Ty>) { + arg.extend_integer_width_to(32); + } +} |