| // Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| #![allow(non_upper_case_globals)] |
| |
| use libc::c_uint; |
| use std::cmp; |
| use llvm; |
| use llvm::{Integer, Pointer, Float, Double, Struct, Array, Vector, Attribute}; |
| use trans::cabi::{ArgType, FnType}; |
| use trans::context::CrateContext; |
| use trans::type_::Type; |
| |
| fn align_up_to(off: usize, a: usize) -> usize { |
| return (off + a - 1) / a * a; |
| } |
| |
| fn align(off: usize, ty: Type) -> usize { |
| let a = ty_align(ty); |
| return align_up_to(off, a); |
| } |
| |
| fn ty_align(ty: Type) -> usize { |
| match ty.kind() { |
| Integer => ((ty.int_width() as usize) + 7) / 8, |
| Pointer => 4, |
| Float => 4, |
| Double => 8, |
| Struct => { |
| if ty.is_packed() { |
| 1 |
| } else { |
| let str_tys = ty.field_types(); |
| str_tys.iter().fold(1, |a, t| cmp::max(a, ty_align(*t))) |
| } |
| } |
| Array => { |
| let elt = ty.element_type(); |
| ty_align(elt) |
| } |
| Vector => { |
| let len = ty.vector_length(); |
| let elt = ty.element_type(); |
| ty_align(elt) * len |
| } |
| _ => panic!("ty_align: unhandled type") |
| } |
| } |
| |
| fn ty_size(ty: Type) -> usize { |
| match ty.kind() { |
| Integer => ((ty.int_width() as usize) + 7) / 8, |
| Pointer => 4, |
| Float => 4, |
| Double => 8, |
| Struct => { |
| if ty.is_packed() { |
| let str_tys = ty.field_types(); |
| str_tys.iter().fold(0, |s, t| s + ty_size(*t)) |
| } else { |
| let str_tys = ty.field_types(); |
| let size = str_tys.iter().fold(0, |s, t| align(s, *t) + ty_size(*t)); |
| align(size, ty) |
| } |
| } |
| Array => { |
| let len = ty.array_length(); |
| let elt = ty.element_type(); |
| let eltsz = ty_size(elt); |
| len * eltsz |
| } |
| Vector => { |
| let len = ty.vector_length(); |
| let elt = ty.element_type(); |
| let eltsz = ty_size(elt); |
| len * eltsz |
| } |
| _ => panic!("ty_size: unhandled type") |
| } |
| } |
| |
| fn classify_ret_ty(ccx: &CrateContext, ty: Type) -> ArgType { |
| if is_reg_ty(ty) { |
| let attr = if ty == Type::i1(ccx) { Some(Attribute::ZExt) } else { None }; |
| ArgType::direct(ty, None, None, attr) |
| } else { |
| ArgType::indirect(ty, Some(Attribute::StructRet)) |
| } |
| } |
| |
| fn classify_arg_ty(ccx: &CrateContext, ty: Type, offset: &mut usize) -> ArgType { |
| let orig_offset = *offset; |
| let size = ty_size(ty) * 8; |
| let mut align = ty_align(ty); |
| |
| align = cmp::min(cmp::max(align, 4), 8); |
| *offset = align_up_to(*offset, align); |
| *offset += align_up_to(size, align * 8) / 8; |
| |
| if is_reg_ty(ty) { |
| let attr = if ty == Type::i1(ccx) { Some(Attribute::ZExt) } else { None }; |
| ArgType::direct(ty, None, None, attr) |
| } else { |
| ArgType::direct( |
| ty, |
| Some(struct_ty(ccx, ty)), |
| padding_ty(ccx, align, orig_offset), |
| None |
| ) |
| } |
| } |
| |
| fn is_reg_ty(ty: Type) -> bool { |
| return match ty.kind() { |
| Integer |
| | Pointer |
| | Float |
| | Double |
| | Vector => true, |
| _ => false |
| }; |
| } |
| |
| fn padding_ty(ccx: &CrateContext, align: usize, offset: usize) -> Option<Type> { |
| if ((align - 1 ) & offset) > 0 { |
| Some(Type::i32(ccx)) |
| } else { |
| None |
| } |
| } |
| |
| fn coerce_to_int(ccx: &CrateContext, size: usize) -> Vec<Type> { |
| let int_ty = Type::i32(ccx); |
| let mut args = Vec::new(); |
| |
| let mut n = size / 32; |
| while n > 0 { |
| args.push(int_ty); |
| n -= 1; |
| } |
| |
| let r = size % 32; |
| if r > 0 { |
| unsafe { |
| args.push(Type::from_ref(llvm::LLVMIntTypeInContext(ccx.llcx(), r as c_uint))); |
| } |
| } |
| |
| args |
| } |
| |
| fn struct_ty(ccx: &CrateContext, ty: Type) -> Type { |
| let size = ty_size(ty) * 8; |
| Type::struct_(ccx, &coerce_to_int(ccx, size), false) |
| } |
| |
| pub fn compute_abi_info(ccx: &CrateContext, |
| atys: &[Type], |
| rty: Type, |
| ret_def: bool) -> FnType { |
| let ret_ty = if ret_def { |
| classify_ret_ty(ccx, rty) |
| } else { |
| ArgType::direct(Type::void(ccx), None, None, None) |
| }; |
| |
| let sret = ret_ty.is_indirect(); |
| let mut arg_tys = Vec::new(); |
| let mut offset = if sret { 4 } else { 0 }; |
| |
| for aty in atys { |
| let ty = classify_arg_ty(ccx, *aty, &mut offset); |
| arg_tys.push(ty); |
| }; |
| |
| return FnType { |
| arg_tys: arg_tys, |
| ret_ty: ret_ty, |
| }; |
| } |