src/librustc_target/abi/call/wasm32.rs

   1 use crate::abi::call::{FnType, ArgType, Uniform};
   2 use crate::abi::{HasDataLayout, LayoutOf, TyLayout, TyLayoutMethods};
   3
   4 fn unwrap_trivial_aggregate<'a, Ty, C>(cx: &C, val: &mut ArgType<'a, Ty>) -> bool
   5     where Ty: TyLayoutMethods<'a, C> + Copy,
   6           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
   7 {
   8     if val.layout.is_aggregate() {
   9         if let Some(unit) = val.layout.homogeneous_aggregate(cx).unit() {
  10             let size = val.layout.size;
  11             if unit.size == size {
  12                 val.cast_to(Uniform {
  13                     unit,
  14                     total: size
  15                 });
  16                 return true;
  17             }
  18         }
  19     }
  20     false
  21 }
  22
  23
  24 fn classify_ret_ty<'a, Ty, C>(cx: &C, ret: &mut ArgType<'a, Ty>)
  25     where Ty: TyLayoutMethods<'a, C> + Copy,
  26           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
  27 {
  28     ret.extend_integer_width_to(32);
  29     if ret.layout.is_aggregate() {
  30         if !unwrap_trivial_aggregate(cx, ret) {
  31             ret.make_indirect();
  32         }
  33     }
  34 }
  35
  36 fn classify_arg_ty<'a, Ty, C>(cx: &C, arg: &mut ArgType<'a, Ty>)
  37     where Ty: TyLayoutMethods<'a, C> + Copy,
  38           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
  39 {
  40     arg.extend_integer_width_to(32);
  41     if arg.layout.is_aggregate() {
  42         if !unwrap_trivial_aggregate(cx, arg) {
  43             arg.make_indirect_byval();
  44         }
  45     }
  46 }
  47
  48 pub fn compute_abi_info<'a, Ty, C>(cx: &C, fty: &mut FnType<'a, Ty>)
  49     where Ty: TyLayoutMethods<'a, C> + Copy,
  50           C: LayoutOf<Ty = Ty, TyLayout = TyLayout<'a, Ty>> + HasDataLayout
  51 {
  52     if !fty.ret.is_ignore() {
  53         classify_ret_ty(cx, &mut fty.ret);
  54     }
  55
  56     for arg in &mut fty.args {
  57         if arg.is_ignore() { continue; }
  58         classify_arg_ty(cx, arg);
  59     }
  60 }