1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
12 use rustc::mir::interpret::ConstEvalErr;
13 use rustc_mir::interpret::{read_target_uint, const_val_field};
14 use rustc::hir::def_id::DefId;
16 use rustc_data_structures::indexed_vec::Idx;
17 use rustc_data_structures::sync::Lrc;
18 use rustc::mir::interpret::{GlobalId, Pointer, Scalar, Allocation, ConstValue, AllocType};
19 use rustc::ty::{self, Ty};
20 use rustc::ty::layout::{self, HasDataLayout, LayoutOf, Size};
22 use common::{CodegenCx};
23 use common::{C_bytes, C_struct, C_uint_big, C_undef, C_usize};
25 use type_of::LayoutLlvmExt;
27 use syntax::ast::Mutability;
28 use syntax::codemap::Span;
31 use super::super::callee;
32 use super::FunctionCx;
34 pub fn scalar_to_llvm(
35 cx: &CodegenCx<'ll, '_>,
37 layout: &layout::Scalar,
40 let bitsize = if layout.is_bool() { 1 } else { layout.value.size(cx).bits() };
42 Scalar::Bits { size: 0, .. } => {
43 assert_eq!(0, layout.value.size(cx).bytes());
44 C_undef(Type::ix(cx, 0))
46 Scalar::Bits { bits, size } => {
47 assert_eq!(size as u64, layout.value.size(cx).bytes());
48 let llval = C_uint_big(Type::ix(cx, bitsize), bits);
49 if layout.value == layout::Pointer {
50 unsafe { llvm::LLVMConstIntToPtr(llval, llty) }
52 consts::bitcast(llval, llty)
56 let alloc_type = cx.tcx.alloc_map.lock().get(ptr.alloc_id);
57 let base_addr = match alloc_type {
58 Some(AllocType::Memory(alloc)) => {
59 let init = const_alloc_to_llvm(cx, alloc);
60 if alloc.runtime_mutability == Mutability::Mutable {
61 consts::addr_of_mut(cx, init, alloc.align, None)
63 consts::addr_of(cx, init, alloc.align, None)
66 Some(AllocType::Function(fn_instance)) => {
67 callee::get_fn(cx, fn_instance)
69 Some(AllocType::Static(def_id)) => {
70 assert!(cx.tcx.is_static(def_id).is_some());
71 consts::get_static(cx, def_id)
73 None => bug!("missing allocation {:?}", ptr.alloc_id),
75 let llval = unsafe { llvm::LLVMConstInBoundsGEP(
76 consts::bitcast(base_addr, Type::i8p(cx)),
77 &C_usize(cx, ptr.offset.bytes()),
80 if layout.value != layout::Pointer {
81 unsafe { llvm::LLVMConstPtrToInt(llval, llty) }
83 consts::bitcast(llval, llty)
89 pub fn const_alloc_to_llvm(cx: &CodegenCx<'ll, '_>, alloc: &Allocation) -> &'ll Value {
90 let mut llvals = Vec::with_capacity(alloc.relocations.len() + 1);
91 let layout = cx.data_layout();
92 let pointer_size = layout.pointer_size.bytes() as usize;
94 let mut next_offset = 0;
95 for &(offset, alloc_id) in alloc.relocations.iter() {
96 let offset = offset.bytes();
97 assert_eq!(offset as usize as u64, offset);
98 let offset = offset as usize;
99 if offset > next_offset {
100 llvals.push(C_bytes(cx, &alloc.bytes[next_offset..offset]));
102 let ptr_offset = read_target_uint(
104 &alloc.bytes[offset..(offset + pointer_size)],
105 ).expect("const_alloc_to_llvm: could not read relocation pointer") as u64;
106 llvals.push(scalar_to_llvm(
108 Pointer { alloc_id, offset: Size::from_bytes(ptr_offset) }.into(),
110 value: layout::Primitive::Pointer,
115 next_offset = offset + pointer_size;
117 if alloc.bytes.len() >= next_offset {
118 llvals.push(C_bytes(cx, &alloc.bytes[next_offset ..]));
121 C_struct(cx, &llvals, true)
124 pub fn codegen_static_initializer(
125 cx: &CodegenCx<'ll, 'tcx>,
127 ) -> Result<(&'ll Value, &'tcx Allocation), Lrc<ConstEvalErr<'tcx>>> {
128 let instance = ty::Instance::mono(cx.tcx, def_id);
133 let param_env = ty::ParamEnv::reveal_all();
134 let static_ = cx.tcx.const_eval(param_env.and(cid))?;
136 let alloc = match static_.val {
137 ConstValue::ByRef(alloc, n) if n.bytes() == 0 => alloc,
138 _ => bug!("static const eval returned {:#?}", static_),
140 Ok((const_alloc_to_llvm(cx, alloc), alloc))
143 impl FunctionCx<'a, 'll, 'tcx> {
146 bx: &Builder<'a, 'll, 'tcx>,
147 constant: &'tcx ty::Const<'tcx>,
148 ) -> Result<&'tcx ty::Const<'tcx>, Lrc<ConstEvalErr<'tcx>>> {
150 ConstValue::Unevaluated(def_id, ref substs) => {
152 let param_env = ty::ParamEnv::reveal_all();
153 let instance = ty::Instance::resolve(tcx, param_env, def_id, substs).unwrap();
158 tcx.const_eval(param_env.and(cid))
164 pub fn eval_mir_constant(
166 bx: &Builder<'a, 'll, 'tcx>,
167 constant: &mir::Constant<'tcx>,
168 ) -> Result<&'tcx ty::Const<'tcx>, Lrc<ConstEvalErr<'tcx>>> {
169 let c = self.monomorphize(&constant.literal);
170 self.fully_evaluate(bx, c)
173 /// process constant containing SIMD shuffle indices
174 pub fn simd_shuffle_indices(
176 bx: &Builder<'a, 'll, 'tcx>,
179 constant: Result<&'tcx ty::Const<'tcx>, Lrc<ConstEvalErr<'tcx>>>,
180 ) -> (&'ll Value, Ty<'tcx>) {
183 let field_ty = c.ty.builtin_index().unwrap();
184 let fields = match c.ty.sty {
185 ty::TyArray(_, n) => n.unwrap_usize(bx.tcx()),
186 ref other => bug!("invalid simd shuffle type: {}", other),
188 let values: Result<Vec<_>, Lrc<_>> = (0..fields).map(|field| {
189 let field = const_val_field(
191 ty::ParamEnv::reveal_all(),
194 mir::Field::new(field as usize),
197 if let Some(prim) = field.val.try_to_scalar() {
198 let layout = bx.cx.layout_of(field_ty);
199 let scalar = match layout.abi {
200 layout::Abi::Scalar(ref x) => x,
201 _ => bug!("from_const: invalid ByVal layout: {:#?}", layout)
205 layout.immediate_llvm_type(bx.cx),
208 bug!("simd shuffle field {:?}", field)
211 let llval = C_struct(bx.cx, &values?, false);
214 .unwrap_or_else(|e| {
217 "could not evaluate shuffle_indices at compile time",
219 // We've errored, so we don't have to produce working code.
220 let ty = self.monomorphize(&ty);
221 let llty = bx.cx.layout_of(ty).llvm_type(bx.cx);