]> git.proxmox.com Git - rustc.git/blame - src/librustc_trans/trans/asm.rs
Imported Upstream version 1.8.0+dfsg1
[rustc.git] / src / librustc_trans / trans / asm.rs
CommitLineData
1a4d82fc
JJ
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.
4//
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.
10
11//! # Translation of inline assembly.
12
13use llvm;
14use trans::build::*;
15use trans::callee;
16use trans::common::*;
17use trans::cleanup;
18use trans::cleanup::CleanupMethods;
19use trans::expr;
20use trans::type_of;
21use trans::type_::Type;
22
e9174d1e 23use rustc_front::hir as ast;
1a4d82fc 24use std::ffi::CString;
b039eaaf 25use syntax::ast::AsmDialect;
1a4d82fc
JJ
26use libc::{c_uint, c_char};
27
28// Take an inline assembly expression and splat it out via LLVM
29pub fn trans_inline_asm<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ia: &ast::InlineAsm)
30 -> Block<'blk, 'tcx> {
31 let fcx = bcx.fcx;
32 let mut bcx = bcx;
33 let mut constraints = Vec::new();
34 let mut output_types = Vec::new();
35
36 let temp_scope = fcx.push_custom_cleanup_scope();
37
38 let mut ext_inputs = Vec::new();
39 let mut ext_constraints = Vec::new();
40
41 // Prepare the output operands
9cc50fc6
SL
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());
1a4d82fc 46
7453a54e 47 let out_datum = unpack_datum!(bcx, expr::trans(bcx, &out.expr));
9cc50fc6 48 if out.is_indirect {
62682a34 49 bcx = callee::trans_arg_datum(bcx,
7453a54e 50 expr_ty(bcx, &out.expr),
62682a34
SL
51 out_datum,
52 cleanup::CustomScope(temp_scope),
53 callee::DontAutorefArg,
9cc50fc6
SL
54 &mut inputs);
55 if out.is_rw {
56 ext_inputs.push(*inputs.last().unwrap());
57 ext_constraints.push(i.to_string());
58 }
59 } else {
60 output_types.push(type_of::type_of(bcx.ccx(), out_datum.ty));
61 outputs.push(out_datum.val);
62 if out.is_rw {
63 bcx = callee::trans_arg_datum(bcx,
7453a54e 64 expr_ty(bcx, &out.expr),
9cc50fc6
SL
65 out_datum,
66 cleanup::CustomScope(temp_scope),
67 callee::DontAutorefArg,
68 &mut ext_inputs);
69 ext_constraints.push(i.to_string());
70 }
1a4d82fc 71 }
9cc50fc6 72 }
1a4d82fc
JJ
73
74 // Now the input operands
62682a34 75 for &(ref c, ref input) in &ia.inputs {
1a4d82fc
JJ
76 constraints.push((*c).clone());
77
7453a54e 78 let in_datum = unpack_datum!(bcx, expr::trans(bcx, &input));
62682a34 79 bcx = callee::trans_arg_datum(bcx,
7453a54e 80 expr_ty(bcx, &input),
1a4d82fc
JJ
81 in_datum,
82 cleanup::CustomScope(temp_scope),
62682a34
SL
83 callee::DontAutorefArg,
84 &mut inputs);
85 }
92a42be0 86 inputs.extend_from_slice(&ext_inputs[..]);
1a4d82fc
JJ
87
88 // no failure occurred preparing operands, no need to cleanup
89 fcx.pop_custom_cleanup_scope(temp_scope);
90
c34b1796
AL
91 let clobbers = ia.clobbers.iter()
92 .map(|s| format!("~{{{}}}", &s));
93
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}"),
98 _ => Vec::new()
99 };
1a4d82fc 100
c34b1796
AL
101 let all_constraints= constraints.iter()
102 .map(|s| s.to_string())
62682a34 103 .chain(ext_constraints)
c34b1796
AL
104 .chain(clobbers)
105 .chain(arch_clobbers.iter()
106 .map(|s| s.to_string()))
107 .collect::<Vec<String>>()
c1a9b12d 108 .join(",");
1a4d82fc 109
c34b1796 110 debug!("Asm Constraints: {}", &all_constraints[..]);
1a4d82fc
JJ
111
112 // Depending on how many outputs we have, the return type is different
c34b1796
AL
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)
1a4d82fc
JJ
118 };
119
120 let dialect = match ia.dialect {
b039eaaf
SL
121 AsmDialect::Att => llvm::AD_ATT,
122 AsmDialect::Intel => llvm::AD_Intel
1a4d82fc
JJ
123 };
124
85aaf69f 125 let asm = CString::new(ia.asm.as_bytes()).unwrap();
c34b1796 126 let constraint_cstr = CString::new(all_constraints).unwrap();
1a4d82fc
JJ
127 let r = InlineAsmCall(bcx,
128 asm.as_ptr(),
c34b1796 129 constraint_cstr.as_ptr(),
85aaf69f 130 &inputs,
1a4d82fc
JJ
131 output_type,
132 ia.volatile,
133 ia.alignstack,
134 dialect);
135
136 // Again, based on how many outputs we have
137 if num_outputs == 1 {
138 Store(bcx, r, outputs[0]);
139 } else {
140 for (i, o) in outputs.iter().enumerate() {
141 let v = ExtractValue(bcx, r, i);
142 Store(bcx, v, *o);
143 }
144 }
145
146 // Store expn_id in a metadata node so we can map LLVM errors
147 // back to source locations. See #17552.
148 unsafe {
149 let key = "srcloc";
150 let kind = llvm::LLVMGetMDKindIDInContext(bcx.ccx().llcx(),
151 key.as_ptr() as *const c_char, key.len() as c_uint);
152
d9579d0f 153 let val: llvm::ValueRef = C_i32(bcx.ccx(), ia.expn_id.into_u32() as i32);
1a4d82fc
JJ
154
155 llvm::LLVMSetMetadata(r, kind,
156 llvm::LLVMMDNodeInContext(bcx.ccx().llcx(), &val, 1));
157 }
158
159 return bcx;
160
161}