rust/src/librustc_trans/trans/asm.rs

177 lines
5.5 KiB
Rust
Raw Normal View History

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/*!
# Translation of inline assembly.
*/
use llvm;
use trans::build::*;
use trans::callee;
use trans::common::*;
use trans::cleanup;
use trans::cleanup::CleanupMethods;
use trans::expr;
use trans::type_of;
use trans::type_::Type;
2013-06-16 05:52:44 -05:00
use std::c_str::ToCStr;
use std::string::String;
use syntax::ast;
use libc::{c_uint, c_char};
// Take an inline assembly expression and splat it out via LLVM
pub fn trans_inline_asm<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, ia: &ast::InlineAsm)
-> Block<'blk, 'tcx> {
let fcx = bcx.fcx;
let mut bcx = bcx;
let mut constraints = Vec::new();
let mut output_types = Vec::new();
let temp_scope = fcx.push_custom_cleanup_scope();
let mut ext_inputs = Vec::new();
let mut ext_constraints = Vec::new();
// Prepare the output operands
let outputs = ia.outputs.iter().enumerate().map(|(i, &(ref c, ref out, is_rw))| {
constraints.push((*c).clone());
2014-05-16 12:15:33 -05:00
let out_datum = unpack_datum!(bcx, expr::trans(bcx, &**out));
output_types.push(type_of::type_of(bcx.ccx(), out_datum.ty));
let val = out_datum.val;
if is_rw {
ext_inputs.push(unpack_result!(bcx, {
callee::trans_arg_datum(bcx,
expr_ty(bcx, &**out),
out_datum,
cleanup::CustomScope(temp_scope),
callee::DontAutorefArg)
}));
ext_constraints.push(i.to_string());
}
val
}).collect::<Vec<_>>();
// Now the input operands
let mut inputs = ia.inputs.iter().map(|&(ref c, ref input)| {
constraints.push((*c).clone());
2014-05-16 12:15:33 -05:00
let in_datum = unpack_datum!(bcx, expr::trans(bcx, &**input));
unpack_result!(bcx, {
callee::trans_arg_datum(bcx,
2014-09-07 12:09:06 -05:00
expr_ty(bcx, &**input),
in_datum,
cleanup::CustomScope(temp_scope),
callee::DontAutorefArg)
})
}).collect::<Vec<_>>();
inputs.push_all(ext_inputs.as_slice());
// no failure occurred preparing operands, no need to cleanup
fcx.pop_custom_cleanup_scope(temp_scope);
let mut constraints =
String::from_str(constraints.iter()
.map(|s| s.get().to_string())
2014-09-14 22:27:36 -05:00
.chain(ext_constraints.into_iter())
.collect::<Vec<String>>()
.connect(",")
.as_slice());
let mut clobbers = get_clobbers();
if !ia.clobbers.get().is_empty() && !clobbers.is_empty() {
clobbers = format!("{},{}", ia.clobbers.get(), clobbers);
} else {
clobbers.push_str(ia.clobbers.get());
}
// Add the clobbers to our constraints list
if clobbers.len() != 0 && constraints.len() != 0 {
constraints.push(',');
constraints.push_str(clobbers.as_slice());
} else {
constraints.push_str(clobbers.as_slice());
}
2014-10-15 01:25:34 -05:00
debug!("Asm Constraints: {}", constraints.as_slice());
let num_outputs = outputs.len();
// Depending on how many outputs we have, the return type is different
let output_type = if num_outputs == 0 {
Type::void(bcx.ccx())
} else if num_outputs == 1 {
output_types[0]
} else {
Type::struct_(bcx.ccx(), output_types.as_slice(), false)
};
let dialect = match ia.dialect {
ast::AsmAtt => llvm::AD_ATT,
ast::AsmIntel => llvm::AD_Intel
};
let r = ia.asm.get().with_c_str(|a| {
constraints.as_slice().with_c_str(|c| {
InlineAsmCall(bcx,
a,
c,
inputs.as_slice(),
output_type,
ia.volatile,
ia.alignstack,
dialect)
})
});
2013-03-28 18:34:10 -05:00
// Again, based on how many outputs we have
if num_outputs == 1 {
Store(bcx, r, outputs[0]);
} else {
for (i, o) in outputs.iter().enumerate() {
let v = ExtractValue(bcx, r, i);
Store(bcx, v, *o);
}
}
// Store expn_id in a metadata node so we can map LLVM errors
// back to source locations. See #17552.
unsafe {
let key = "srcloc";
let kind = llvm::LLVMGetMDKindIDInContext(bcx.ccx().llcx(),
key.as_ptr() as *const c_char, key.len() as c_uint);
let val: llvm::ValueRef = C_i32(bcx.ccx(), ia.expn_id.to_llvm_cookie());
llvm::LLVMSetMetadata(r, kind,
llvm::LLVMMDNodeInContext(bcx.ccx().llcx(), &val, 1));
}
return bcx;
}
// Default per-arch clobbers
// Basically what clang does
2014-09-29 01:39:03 -05:00
#[cfg(any(target_arch = "arm",
target_arch = "mips",
target_arch = "mipsel"))]
fn get_clobbers() -> String {
"".to_string()
}
2014-09-29 01:39:03 -05:00
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn get_clobbers() -> String {
"~{dirflag},~{fpsr},~{flags}".to_string()
}