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};
23 use mir::lvalue::Alignment;
25 use std::ffi::CString;
26 use syntax::ast::AsmDialect;
27 use libc::{c_uint, c_char};
29 // Take an inline assembly expression and splat it out via LLVM
30 pub fn trans_inline_asm<'a, 'tcx>(
31 bcx: &Builder<'a, 'tcx>,
33 outputs: Vec<(ValueRef, Ty<'tcx>)>,
34 mut inputs: Vec<ValueRef>
36 let mut ext_constraints = vec![];
37 let mut output_types = vec![];
39 // Prepare the output operands
40 let mut indirect_outputs = vec![];
41 for (i, (out, &(val, ty))) in ia.outputs.iter().zip(&outputs).enumerate() {
42 let val = if out.is_rw || out.is_indirect {
43 Some(base::load_ty(bcx, val, Alignment::Packed, ty))
48 inputs.push(val.unwrap());
49 ext_constraints.push(i.to_string());
52 indirect_outputs.push(val.unwrap());
54 output_types.push(type_of::type_of(bcx.ccx, ty));
57 if !indirect_outputs.is_empty() {
58 indirect_outputs.extend_from_slice(&inputs);
59 inputs = indirect_outputs;
62 let clobbers = ia.clobbers.iter()
63 .map(|s| format!("~{{{}}}", &s));
65 // Default per-arch clobbers
66 // Basically what clang does
67 let arch_clobbers = match &bcx.sess().target.target.arch[..] {
68 "x86" | "x86_64" => vec!["~{dirflag}", "~{fpsr}", "~{flags}"],
73 ia.outputs.iter().map(|out| out.constraint.to_string())
74 .chain(ia.inputs.iter().map(|s| s.to_string()))
75 .chain(ext_constraints)
77 .chain(arch_clobbers.iter().map(|s| s.to_string()))
78 .collect::<Vec<String>>().join(",");
80 debug!("Asm Constraints: {}", &all_constraints);
82 // Depending on how many outputs we have, the return type is different
83 let num_outputs = output_types.len();
84 let output_type = match num_outputs {
85 0 => Type::void(bcx.ccx),
87 _ => Type::struct_(bcx.ccx, &output_types, false)
90 let dialect = match ia.dialect {
91 AsmDialect::Att => llvm::AsmDialect::Att,
92 AsmDialect::Intel => llvm::AsmDialect::Intel,
95 let asm = CString::new(ia.asm.as_str().as_bytes()).unwrap();
96 let constraint_cstr = CString::new(all_constraints).unwrap();
97 let r = bcx.inline_asm_call(
99 constraint_cstr.as_ptr(),
107 // Again, based on how many outputs we have
108 let outputs = ia.outputs.iter().zip(&outputs).filter(|&(ref o, _)| !o.is_indirect);
109 for (i, (_, &(val, _))) in outputs.enumerate() {
110 let v = if num_outputs == 1 { r } else { bcx.extract_value(r, i) };
111 bcx.store(v, val, None);
114 // Store mark in a metadata node so we can map LLVM errors
115 // back to source locations. See #17552.
118 let kind = llvm::LLVMGetMDKindIDInContext(bcx.ccx.llcx(),
119 key.as_ptr() as *const c_char, key.len() as c_uint);
121 let val: llvm::ValueRef = C_i32(bcx.ccx, ia.ctxt.outer().as_u32() as i32);
123 llvm::LLVMSetMetadata(r, kind,
124 llvm::LLVMMDNodeInContext(bcx.ccx.llcx(), &val, 1));
128 pub fn trans_global_asm<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
129 ga: &hir::GlobalAsm) {
130 let asm = CString::new(ga.asm.as_str().as_bytes()).unwrap();
132 llvm::LLVMSetModuleInlineAsm(ccx.llmod(), asm.as_ptr());