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,
80 expr_ty(bcx, &**input),
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));