1 // Copyright 2012-2015 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.
11 //! # Translation of inline assembly.
13 use llvm
::{self, ValueRef}
;
17 use datum
::{Datum, Lvalue}
;
21 use rustc
::hir
as ast
;
22 use std
::ffi
::CString
;
23 use syntax
::ast
::AsmDialect
;
24 use libc
::{c_uint, c_char}
;
26 // Take an inline assembly expression and splat it out via LLVM
27 pub fn trans_inline_asm
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>,
29 outputs
: Vec
<Datum
<'tcx
, Lvalue
>>,
30 mut inputs
: Vec
<ValueRef
>) {
31 let mut ext_constraints
= vec
![];
32 let mut output_types
= vec
![];
34 // Prepare the output operands
35 let mut indirect_outputs
= vec
![];
36 for (i
, (out
, out_datum
)) in ia
.outputs
.iter().zip(&outputs
).enumerate() {
37 let val
= if out
.is_rw
|| out
.is_indirect
{
38 Some(base
::load_ty(bcx
, out_datum
.val
, out_datum
.ty
))
43 inputs
.push(val
.unwrap());
44 ext_constraints
.push(i
.to_string());
47 indirect_outputs
.push(val
.unwrap());
49 output_types
.push(type_of
::type_of(bcx
.ccx(), out_datum
.ty
));
52 if !indirect_outputs
.is_empty() {
53 indirect_outputs
.extend_from_slice(&inputs
);
54 inputs
= indirect_outputs
;
57 let clobbers
= ia
.clobbers
.iter()
58 .map(|s
| format
!("~{{{}}}", &s
));
60 // Default per-arch clobbers
61 // Basically what clang does
62 let arch_clobbers
= match &bcx
.sess().target
.target
.arch
[..] {
63 "x86" | "x86_64" => vec
!("~{dirflag}", "~{fpsr}", "~{flags}"),
68 ia
.outputs
.iter().map(|out
| out
.constraint
.to_string())
69 .chain(ia
.inputs
.iter().map(|s
| s
.to_string()))
70 .chain(ext_constraints
)
72 .chain(arch_clobbers
.iter().map(|s
| s
.to_string()))
73 .collect
::<Vec
<String
>>().join(",");
75 debug
!("Asm Constraints: {}", &all_constraints
[..]);
77 // Depending on how many outputs we have, the return type is different
78 let num_outputs
= output_types
.len();
79 let output_type
= match num_outputs
{
80 0 => Type
::void(bcx
.ccx()),
82 _
=> Type
::struct_(bcx
.ccx(), &output_types
[..], false)
85 let dialect
= match ia
.dialect
{
86 AsmDialect
::Att
=> llvm
::AD_ATT
,
87 AsmDialect
::Intel
=> llvm
::AD_Intel
90 let asm
= CString
::new(ia
.asm
.as_bytes()).unwrap();
91 let constraint_cstr
= CString
::new(all_constraints
).unwrap();
92 let r
= InlineAsmCall(bcx
,
94 constraint_cstr
.as_ptr(),
101 // Again, based on how many outputs we have
102 let outputs
= ia
.outputs
.iter().zip(&outputs
).filter(|&(ref o
, _
)| !o
.is_indirect
);
103 for (i
, (_
, datum
)) in outputs
.enumerate() {
104 let v
= if num_outputs
== 1 { r }
else { ExtractValue(bcx, r, i) }
;
105 Store(bcx
, v
, datum
.val
);
108 // Store expn_id in a metadata node so we can map LLVM errors
109 // back to source locations. See #17552.
112 let kind
= llvm
::LLVMGetMDKindIDInContext(bcx
.ccx().llcx(),
113 key
.as_ptr() as *const c_char
, key
.len() as c_uint
);
115 let val
: llvm
::ValueRef
= C_i32(bcx
.ccx(), ia
.expn_id
.into_u32() as i32);
117 llvm
::LLVMSetMetadata(r
, kind
,
118 llvm
::LLVMMDNodeInContext(bcx
.ccx().llcx(), &val
, 1));