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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.
18 use trans
::cleanup
::CleanupMethods
;
21 use trans
::type_
::Type
;
23 use rustc_front
::hir
as ast
;
24 use std
::ffi
::CString
;
25 use syntax
::ast
::AsmDialect
;
26 use libc
::{c_uint, c_char}
;
28 // Take an inline assembly expression and splat it out via LLVM
29 pub fn trans_inline_asm
<'blk
, 'tcx
>(bcx
: Block
<'blk
, 'tcx
>, ia
: &ast
::InlineAsm
)
30 -> Block
<'blk
, 'tcx
> {
33 let mut constraints
= Vec
::new();
34 let mut output_types
= Vec
::new();
36 let temp_scope
= fcx
.push_custom_cleanup_scope();
38 let mut ext_inputs
= Vec
::new();
39 let mut ext_constraints
= Vec
::new();
41 // Prepare the output operands
42 let mut outputs
= Vec
::new();
43 let mut inputs
= Vec
::new();
44 for (i
, out
) in ia
.outputs
.iter().enumerate() {
45 constraints
.push(out
.constraint
.clone());
47 let out_datum
= unpack_datum
!(bcx
, expr
::trans(bcx
, &out
.expr
));
49 bcx
= callee
::trans_arg_datum(bcx
,
50 expr_ty(bcx
, &out
.expr
),
52 cleanup
::CustomScope(temp_scope
),
53 callee
::DontAutorefArg
,
56 ext_inputs
.push(*inputs
.last().unwrap());
57 ext_constraints
.push(i
.to_string());
60 output_types
.push(type_of
::type_of(bcx
.ccx(), out_datum
.ty
));
61 outputs
.push(out_datum
.val
);
63 bcx
= callee
::trans_arg_datum(bcx
,
64 expr_ty(bcx
, &out
.expr
),
66 cleanup
::CustomScope(temp_scope
),
67 callee
::DontAutorefArg
,
69 ext_constraints
.push(i
.to_string());
74 // Now the input operands
75 for &(ref c
, ref input
) in &ia
.inputs
{
76 constraints
.push((*c
).clone());
78 let in_datum
= unpack_datum
!(bcx
, expr
::trans(bcx
, &input
));
79 bcx
= callee
::trans_arg_datum(bcx
,
82 cleanup
::CustomScope(temp_scope
),
83 callee
::DontAutorefArg
,
86 inputs
.extend_from_slice(&ext_inputs
[..]);
88 // no failure occurred preparing operands, no need to cleanup
89 fcx
.pop_custom_cleanup_scope(temp_scope
);
91 let clobbers
= ia
.clobbers
.iter()
92 .map(|s
| format
!("~{{{}}}", &s
));
94 // Default per-arch clobbers
95 // Basically what clang does
96 let arch_clobbers
= match &bcx
.sess().target
.target
.arch
[..] {
97 "x86" | "x86_64" => vec
!("~{dirflag}", "~{fpsr}", "~{flags}"),
101 let all_constraints
= constraints
.iter()
102 .map(|s
| s
.to_string())
103 .chain(ext_constraints
)
105 .chain(arch_clobbers
.iter()
106 .map(|s
| s
.to_string()))
107 .collect
::<Vec
<String
>>()
110 debug
!("Asm Constraints: {}", &all_constraints
[..]);
112 // Depending on how many outputs we have, the return type is different
113 let num_outputs
= outputs
.len();
114 let output_type
= match num_outputs
{
115 0 => Type
::void(bcx
.ccx()),
116 1 => output_types
[0],
117 _
=> Type
::struct_(bcx
.ccx(), &output_types
[..], false)
120 let dialect
= match ia
.dialect
{
121 AsmDialect
::Att
=> llvm
::AD_ATT
,
122 AsmDialect
::Intel
=> llvm
::AD_Intel
125 let asm
= CString
::new(ia
.asm
.as_bytes()).unwrap();
126 let constraint_cstr
= CString
::new(all_constraints
).unwrap();
127 let r
= InlineAsmCall(bcx
,
129 constraint_cstr
.as_ptr(),
136 // Again, based on how many outputs we have
137 if num_outputs
== 1 {
138 Store(bcx
, r
, outputs
[0]);
140 for (i
, o
) in outputs
.iter().enumerate() {
141 let v
= ExtractValue(bcx
, r
, i
);
146 // Store expn_id in a metadata node so we can map LLVM errors
147 // back to source locations. See #17552.
150 let kind
= llvm
::LLVMGetMDKindIDInContext(bcx
.ccx().llcx(),
151 key
.as_ptr() as *const c_char
, key
.len() as c_uint
);
153 let val
: llvm
::ValueRef
= C_i32(bcx
.ccx(), ia
.expn_id
.into_u32() as i32);
155 llvm
::LLVMSetMetadata(r
, kind
,
156 llvm
::LLVMMDNodeInContext(bcx
.ccx().llcx(), &val
, 1));