877 lines
32 KiB
Rust
877 lines
32 KiB
Rust
// Copyright 2012-2013 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.
|
|
|
|
|
|
use back::{link};
|
|
use lib::llvm::llvm;
|
|
use lib::llvm::{ValueRef, CallConv, StructRetAttribute};
|
|
use lib;
|
|
use middle::trans::base::push_ctxt;
|
|
use middle::trans::base;
|
|
use middle::trans::build::*;
|
|
use middle::trans::builder::noname;
|
|
use middle::trans::cabi;
|
|
use middle::trans::common::*;
|
|
use middle::trans::machine;
|
|
use middle::trans::type_::Type;
|
|
use middle::trans::type_of::*;
|
|
use middle::trans::type_of;
|
|
use middle::ty::FnSig;
|
|
use middle::ty;
|
|
use std::cmp;
|
|
use std::libc::c_uint;
|
|
use std::vec;
|
|
use syntax::abi::{Cdecl, Aapcs, C, AbiSet, Win64};
|
|
use syntax::abi::{RustIntrinsic, Rust, Stdcall, Fastcall, System};
|
|
use syntax::codemap::Span;
|
|
use syntax::parse::token::special_idents;
|
|
use syntax::{ast};
|
|
use syntax::{attr, ast_map};
|
|
use util::ppaux::{Repr, UserString};
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
// Type definitions
|
|
|
|
struct ForeignTypes {
|
|
/// Rust signature of the function
|
|
fn_sig: ty::FnSig,
|
|
|
|
/// Adapter object for handling native ABI rules (trust me, you
|
|
/// don't want to know)
|
|
fn_ty: cabi::FnType,
|
|
|
|
/// LLVM types that will appear on the foreign function
|
|
llsig: LlvmSignature,
|
|
|
|
/// True if there is a return value (not bottom, not unit)
|
|
ret_def: bool,
|
|
}
|
|
|
|
struct LlvmSignature {
|
|
// LLVM versions of the types of this function's arguments.
|
|
llarg_tys: ~[Type],
|
|
|
|
// LLVM version of the type that this function returns. Note that
|
|
// this *may not be* the declared return type of the foreign
|
|
// function, because the foreign function may opt to return via an
|
|
// out pointer.
|
|
llret_ty: Type,
|
|
|
|
// True if *Rust* would use an outpointer for this function.
|
|
sret: bool,
|
|
}
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
// Calls to external functions
|
|
|
|
pub fn llvm_calling_convention(ccx: &mut CrateContext,
|
|
abis: AbiSet) -> Option<CallConv> {
|
|
let os = ccx.sess.targ_cfg.os;
|
|
let arch = ccx.sess.targ_cfg.arch;
|
|
abis.for_target(os, arch).map(|abi| {
|
|
match abi {
|
|
RustIntrinsic => {
|
|
// Intrinsics are emitted by monomorphic fn
|
|
ccx.sess.bug(format!("Asked to register intrinsic fn"));
|
|
}
|
|
|
|
Rust => {
|
|
// FIXME(#3678) Implement linking to foreign fns with Rust ABI
|
|
ccx.sess.unimpl(
|
|
format!("Foreign functions with Rust ABI"));
|
|
}
|
|
|
|
// It's the ABI's job to select this, not us.
|
|
System => ccx.sess.bug("System abi should be selected elsewhere"),
|
|
|
|
Stdcall => lib::llvm::X86StdcallCallConv,
|
|
Fastcall => lib::llvm::X86FastcallCallConv,
|
|
C => lib::llvm::CCallConv,
|
|
Win64 => lib::llvm::X86_64_Win64,
|
|
|
|
// These API constants ought to be more specific...
|
|
Cdecl => lib::llvm::CCallConv,
|
|
Aapcs => lib::llvm::CCallConv,
|
|
}
|
|
})
|
|
}
|
|
|
|
|
|
pub fn register_foreign_item_fn(ccx: @mut CrateContext,
|
|
abis: AbiSet,
|
|
path: &ast_map::path,
|
|
foreign_item: @ast::foreign_item) -> ValueRef {
|
|
/*!
|
|
* Registers a foreign function found in a library.
|
|
* Just adds a LLVM global.
|
|
*/
|
|
|
|
debug!("register_foreign_item_fn(abis={}, \
|
|
path={}, \
|
|
foreign_item.id={:?})",
|
|
abis.repr(ccx.tcx),
|
|
path.repr(ccx.tcx),
|
|
foreign_item.id);
|
|
|
|
let cc = match llvm_calling_convention(ccx, abis) {
|
|
Some(cc) => cc,
|
|
None => {
|
|
ccx.sess.span_fatal(foreign_item.span,
|
|
format!("ABI `{}` has no suitable ABI \
|
|
for target architecture \
|
|
in module {}",
|
|
abis.user_string(ccx.tcx),
|
|
ast_map::path_to_str(*path,
|
|
ccx.sess.intr())));
|
|
}
|
|
};
|
|
|
|
// Register the function as a C extern fn
|
|
let lname = link_name(ccx, foreign_item);
|
|
let tys = foreign_types_for_id(ccx, foreign_item.id);
|
|
|
|
// Make sure the calling convention is right for variadic functions
|
|
// (should've been caught if not in typeck)
|
|
if tys.fn_sig.variadic {
|
|
assert!(cc == lib::llvm::CCallConv);
|
|
}
|
|
|
|
// Create the LLVM value for the C extern fn
|
|
let llfn_ty = lltype_for_fn_from_foreign_types(&tys);
|
|
let llfn = base::get_extern_fn(&mut ccx.externs, ccx.llmod,
|
|
lname, cc, llfn_ty);
|
|
add_argument_attributes(&tys, llfn);
|
|
|
|
return llfn;
|
|
}
|
|
|
|
pub fn trans_native_call(bcx: @Block,
|
|
callee_ty: ty::t,
|
|
llfn: ValueRef,
|
|
llretptr: ValueRef,
|
|
llargs_rust: &[ValueRef],
|
|
passed_arg_tys: ~[ty::t]) -> @Block {
|
|
/*!
|
|
* Prepares a call to a native function. This requires adapting
|
|
* from the Rust argument passing rules to the native rules.
|
|
*
|
|
* # Parameters
|
|
*
|
|
* - `callee_ty`: Rust type for the function we are calling
|
|
* - `llfn`: the function pointer we are calling
|
|
* - `llretptr`: where to store the return value of the function
|
|
* - `llargs_rust`: a list of the argument values, prepared
|
|
* as they would be if calling a Rust function
|
|
* - `passed_arg_tys`: Rust type for the arguments. Normally we
|
|
* can derive these from callee_ty but in the case of variadic
|
|
* functions passed_arg_tys will include the Rust type of all
|
|
* the arguments including the ones not specified in the fn's signature.
|
|
*/
|
|
|
|
let ccx = bcx.ccx();
|
|
let tcx = bcx.tcx();
|
|
|
|
debug!("trans_native_call(callee_ty={}, \
|
|
llfn={}, \
|
|
llretptr={})",
|
|
callee_ty.repr(tcx),
|
|
ccx.tn.val_to_str(llfn),
|
|
ccx.tn.val_to_str(llretptr));
|
|
|
|
let (fn_abis, fn_sig) = match ty::get(callee_ty).sty {
|
|
ty::ty_bare_fn(ref fn_ty) => (fn_ty.abis, fn_ty.sig.clone()),
|
|
_ => ccx.sess.bug("trans_native_call called on non-function type")
|
|
};
|
|
let llsig = foreign_signature(ccx, &fn_sig, passed_arg_tys);
|
|
let ret_def = !ty::type_is_voidish(bcx.tcx(), fn_sig.output);
|
|
let fn_type = cabi::compute_abi_info(ccx,
|
|
llsig.llarg_tys,
|
|
llsig.llret_ty,
|
|
ret_def);
|
|
|
|
let arg_tys: &[cabi::ArgType] = fn_type.arg_tys;
|
|
|
|
let mut llargs_foreign = ~[];
|
|
|
|
// If the foreign ABI expects return value by pointer, supply the
|
|
// pointer that Rust gave us. Sometimes we have to bitcast
|
|
// because foreign fns return slightly different (but equivalent)
|
|
// views on the same type (e.g., i64 in place of {i32,i32}).
|
|
if fn_type.ret_ty.is_indirect() {
|
|
match fn_type.ret_ty.cast {
|
|
Some(ty) => {
|
|
let llcastedretptr =
|
|
BitCast(bcx, llretptr, ty.ptr_to());
|
|
llargs_foreign.push(llcastedretptr);
|
|
}
|
|
None => {
|
|
llargs_foreign.push(llretptr);
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i, &llarg_rust) in llargs_rust.iter().enumerate() {
|
|
let mut llarg_rust = llarg_rust;
|
|
|
|
// Does Rust pass this argument by pointer?
|
|
let rust_indirect = type_of::arg_is_indirect(ccx, passed_arg_tys[i]);
|
|
|
|
debug!("argument {}, llarg_rust={}, rust_indirect={}, arg_ty={}",
|
|
i,
|
|
ccx.tn.val_to_str(llarg_rust),
|
|
rust_indirect,
|
|
ccx.tn.type_to_str(arg_tys[i].ty));
|
|
|
|
// Ensure that we always have the Rust value indirectly,
|
|
// because it makes bitcasting easier.
|
|
if !rust_indirect {
|
|
let scratch = base::alloca(bcx, type_of::type_of(ccx, passed_arg_tys[i]), "__arg");
|
|
Store(bcx, llarg_rust, scratch);
|
|
llarg_rust = scratch;
|
|
}
|
|
|
|
debug!("llarg_rust={} (after indirection)",
|
|
ccx.tn.val_to_str(llarg_rust));
|
|
|
|
// Check whether we need to do any casting
|
|
match arg_tys[i].cast {
|
|
Some(ty) => llarg_rust = BitCast(bcx, llarg_rust, ty.ptr_to()),
|
|
None => ()
|
|
}
|
|
|
|
debug!("llarg_rust={} (after casting)",
|
|
ccx.tn.val_to_str(llarg_rust));
|
|
|
|
// Finally, load the value if needed for the foreign ABI
|
|
let foreign_indirect = arg_tys[i].is_indirect();
|
|
let llarg_foreign = if foreign_indirect {
|
|
llarg_rust
|
|
} else {
|
|
Load(bcx, llarg_rust)
|
|
};
|
|
|
|
debug!("argument {}, llarg_foreign={}",
|
|
i, ccx.tn.val_to_str(llarg_foreign));
|
|
|
|
// fill padding with undef value
|
|
match arg_tys[i].pad {
|
|
Some(ty) => llargs_foreign.push(C_undef(ty)),
|
|
None => ()
|
|
}
|
|
llargs_foreign.push(llarg_foreign);
|
|
}
|
|
|
|
let cc = match llvm_calling_convention(ccx, fn_abis) {
|
|
Some(cc) => cc,
|
|
None => {
|
|
// FIXME(#8357) We really ought to report a span here
|
|
ccx.sess.fatal(
|
|
format!("ABI string `{}` has no suitable ABI \
|
|
for target architecture",
|
|
fn_abis.user_string(ccx.tcx)));
|
|
}
|
|
};
|
|
|
|
// A function pointer is called without the declaration available, so we have to apply
|
|
// any attributes with ABI implications directly to the call instruction. Right now, the
|
|
// only attribute we need to worry about is `sret`.
|
|
let attrs;
|
|
if fn_type.ret_ty.is_indirect() {
|
|
attrs = &[(1, StructRetAttribute)];
|
|
} else {
|
|
attrs = &[];
|
|
}
|
|
let llforeign_retval = CallWithConv(bcx, llfn, llargs_foreign, cc, attrs);
|
|
|
|
// If the function we just called does not use an outpointer,
|
|
// store the result into the rust outpointer. Cast the outpointer
|
|
// type to match because some ABIs will use a different type than
|
|
// the Rust type. e.g., a {u32,u32} struct could be returned as
|
|
// u64.
|
|
if ret_def && !fn_type.ret_ty.is_indirect() {
|
|
let llrust_ret_ty = llsig.llret_ty;
|
|
let llforeign_ret_ty = match fn_type.ret_ty.cast {
|
|
Some(ty) => ty,
|
|
None => fn_type.ret_ty.ty
|
|
};
|
|
|
|
debug!("llretptr={}", ccx.tn.val_to_str(llretptr));
|
|
debug!("llforeign_retval={}", ccx.tn.val_to_str(llforeign_retval));
|
|
debug!("llrust_ret_ty={}", ccx.tn.type_to_str(llrust_ret_ty));
|
|
debug!("llforeign_ret_ty={}", ccx.tn.type_to_str(llforeign_ret_ty));
|
|
|
|
if llrust_ret_ty == llforeign_ret_ty {
|
|
Store(bcx, llforeign_retval, llretptr);
|
|
} else {
|
|
// The actual return type is a struct, but the ABI
|
|
// adaptation code has cast it into some scalar type. The
|
|
// code that follows is the only reliable way I have
|
|
// found to do a transform like i64 -> {i32,i32}.
|
|
// Basically we dump the data onto the stack then memcpy it.
|
|
//
|
|
// Other approaches I tried:
|
|
// - Casting rust ret pointer to the foreign type and using Store
|
|
// is (a) unsafe if size of foreign type > size of rust type and
|
|
// (b) runs afoul of strict aliasing rules, yielding invalid
|
|
// assembly under -O (specifically, the store gets removed).
|
|
// - Truncating foreign type to correct integral type and then
|
|
// bitcasting to the struct type yields invalid cast errors.
|
|
let llscratch = base::alloca(bcx, llforeign_ret_ty, "__cast");
|
|
Store(bcx, llforeign_retval, llscratch);
|
|
let llscratch_i8 = BitCast(bcx, llscratch, Type::i8().ptr_to());
|
|
let llretptr_i8 = BitCast(bcx, llretptr, Type::i8().ptr_to());
|
|
let llrust_size = machine::llsize_of_store(ccx, llrust_ret_ty);
|
|
let llforeign_align = machine::llalign_of_min(ccx, llforeign_ret_ty);
|
|
let llrust_align = machine::llalign_of_min(ccx, llrust_ret_ty);
|
|
let llalign = cmp::min(llforeign_align, llrust_align);
|
|
debug!("llrust_size={:?}", llrust_size);
|
|
base::call_memcpy(bcx, llretptr_i8, llscratch_i8,
|
|
C_uint(ccx, llrust_size), llalign as u32);
|
|
}
|
|
}
|
|
|
|
return bcx;
|
|
}
|
|
|
|
pub fn trans_foreign_mod(ccx: @mut CrateContext,
|
|
foreign_mod: &ast::foreign_mod) {
|
|
let _icx = push_ctxt("foreign::trans_foreign_mod");
|
|
for &foreign_item in foreign_mod.items.iter() {
|
|
match foreign_item.node {
|
|
ast::foreign_item_fn(..) => {
|
|
let (abis, mut path) = match ccx.tcx.items.get_copy(&foreign_item.id) {
|
|
ast_map::node_foreign_item(_, abis, _, path) => (abis, (*path).clone()),
|
|
_ => fail!("Unable to find foreign item in tcx.items table.")
|
|
};
|
|
if !(abis.is_rust() || abis.is_intrinsic()) {
|
|
path.push(ast_map::path_name(foreign_item.ident));
|
|
register_foreign_item_fn(ccx, abis, &path, foreign_item);
|
|
}
|
|
}
|
|
_ => ()
|
|
}
|
|
|
|
let lname = link_name(ccx, foreign_item);
|
|
let mut item_symbols = ccx.item_symbols.borrow_mut();
|
|
item_symbols.get().insert(foreign_item.id, lname.to_owned());
|
|
}
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
// Rust functions with foreign ABIs
|
|
//
|
|
// These are normal Rust functions defined with foreign ABIs. For
|
|
// now, and perhaps forever, we translate these using a "layer of
|
|
// indirection". That is, given a Rust declaration like:
|
|
//
|
|
// extern "C" fn foo(i: u32) -> u32 { ... }
|
|
//
|
|
// we will generate a function like:
|
|
//
|
|
// S foo(T i) {
|
|
// S r;
|
|
// foo0(&r, NULL, i);
|
|
// return r;
|
|
// }
|
|
//
|
|
// #[inline_always]
|
|
// void foo0(uint32_t *r, void *env, uint32_t i) { ... }
|
|
//
|
|
// Here the (internal) `foo0` function follows the Rust ABI as normal,
|
|
// where the `foo` function follows the C ABI. We rely on LLVM to
|
|
// inline the one into the other. Of course we could just generate the
|
|
// correct code in the first place, but this is much simpler.
|
|
|
|
pub fn register_rust_fn_with_foreign_abi(ccx: @mut CrateContext,
|
|
sp: Span,
|
|
sym: ~str,
|
|
node_id: ast::NodeId)
|
|
-> ValueRef {
|
|
let _icx = push_ctxt("foreign::register_foreign_fn");
|
|
|
|
let tys = foreign_types_for_id(ccx, node_id);
|
|
let llfn_ty = lltype_for_fn_from_foreign_types(&tys);
|
|
let t = ty::node_id_to_type(ccx.tcx, node_id);
|
|
let cconv = match ty::get(t).sty {
|
|
ty::ty_bare_fn(ref fn_ty) => {
|
|
let c = llvm_calling_convention(ccx, fn_ty.abis);
|
|
c.unwrap_or(lib::llvm::CCallConv)
|
|
}
|
|
_ => lib::llvm::CCallConv
|
|
};
|
|
let llfn = base::register_fn_llvmty(ccx,
|
|
sp,
|
|
sym,
|
|
node_id,
|
|
cconv,
|
|
llfn_ty);
|
|
add_argument_attributes(&tys, llfn);
|
|
debug!("register_rust_fn_with_foreign_abi(node_id={:?}, llfn_ty={}, llfn={})",
|
|
node_id, ccx.tn.type_to_str(llfn_ty), ccx.tn.val_to_str(llfn));
|
|
llfn
|
|
}
|
|
|
|
pub fn trans_rust_fn_with_foreign_abi(ccx: @mut CrateContext,
|
|
path: &ast_map::path,
|
|
decl: &ast::fn_decl,
|
|
body: &ast::Block,
|
|
attrs: &[ast::Attribute],
|
|
llwrapfn: ValueRef,
|
|
id: ast::NodeId) {
|
|
let _icx = push_ctxt("foreign::build_foreign_fn");
|
|
let tys = foreign_types_for_id(ccx, id);
|
|
|
|
unsafe { // unsafe because we call LLVM operations
|
|
// Build up the Rust function (`foo0` above).
|
|
let llrustfn = build_rust_fn(ccx, path, decl, body, attrs, id);
|
|
|
|
// Build up the foreign wrapper (`foo` above).
|
|
return build_wrap_fn(ccx, llrustfn, llwrapfn, &tys);
|
|
}
|
|
|
|
fn build_rust_fn(ccx: @mut CrateContext,
|
|
path: &ast_map::path,
|
|
decl: &ast::fn_decl,
|
|
body: &ast::Block,
|
|
attrs: &[ast::Attribute],
|
|
id: ast::NodeId)
|
|
-> ValueRef {
|
|
let _icx = push_ctxt("foreign::foreign::build_rust_fn");
|
|
let tcx = ccx.tcx;
|
|
let t = ty::node_id_to_type(tcx, id);
|
|
let ps = link::mangle_internal_name_by_path(
|
|
ccx, vec::append_one((*path).clone(), ast_map::path_name(
|
|
special_idents::clownshoe_abi
|
|
)));
|
|
|
|
// Compute the type that the function would have if it were just a
|
|
// normal Rust function. This will be the type of the wrappee fn.
|
|
let f = match ty::get(t).sty {
|
|
ty::ty_bare_fn(ref f) => {
|
|
assert!(!f.abis.is_rust() && !f.abis.is_intrinsic());
|
|
f
|
|
}
|
|
_ => {
|
|
ccx.sess.bug(format!("build_rust_fn: extern fn {} has ty {}, \
|
|
expected a bare fn ty",
|
|
path.repr(tcx),
|
|
t.repr(tcx)));
|
|
}
|
|
};
|
|
|
|
debug!("build_rust_fn: path={} id={:?} t={}",
|
|
path.repr(tcx),
|
|
id,
|
|
t.repr(tcx));
|
|
|
|
let llfndecl = base::decl_internal_rust_fn(ccx, f.sig.inputs, f.sig.output, ps);
|
|
base::set_llvm_fn_attrs(attrs, llfndecl);
|
|
base::trans_fn(ccx,
|
|
(*path).clone(),
|
|
decl,
|
|
body,
|
|
llfndecl,
|
|
base::no_self,
|
|
None,
|
|
id,
|
|
[]);
|
|
return llfndecl;
|
|
}
|
|
|
|
unsafe fn build_wrap_fn(ccx: @mut CrateContext,
|
|
llrustfn: ValueRef,
|
|
llwrapfn: ValueRef,
|
|
tys: &ForeignTypes) {
|
|
let _icx = push_ctxt(
|
|
"foreign::trans_rust_fn_with_foreign_abi::build_wrap_fn");
|
|
let tcx = ccx.tcx;
|
|
|
|
debug!("build_wrap_fn(llrustfn={}, llwrapfn={})",
|
|
ccx.tn.val_to_str(llrustfn),
|
|
ccx.tn.val_to_str(llwrapfn));
|
|
|
|
// Avoid all the Rust generation stuff and just generate raw
|
|
// LLVM here.
|
|
//
|
|
// We want to generate code like this:
|
|
//
|
|
// S foo(T i) {
|
|
// S r;
|
|
// foo0(&r, NULL, i);
|
|
// return r;
|
|
// }
|
|
|
|
let the_block =
|
|
"the block".with_c_str(
|
|
|s| llvm::LLVMAppendBasicBlockInContext(ccx.llcx, llwrapfn, s));
|
|
|
|
let builder = ccx.builder.B;
|
|
llvm::LLVMPositionBuilderAtEnd(builder, the_block);
|
|
|
|
// Array for the arguments we will pass to the rust function.
|
|
let mut llrust_args = ~[];
|
|
let mut next_foreign_arg_counter: c_uint = 0;
|
|
let next_foreign_arg: |pad: bool| -> c_uint = |pad: bool| {
|
|
next_foreign_arg_counter += if pad {
|
|
2
|
|
} else {
|
|
1
|
|
};
|
|
next_foreign_arg_counter - 1
|
|
};
|
|
|
|
// If there is an out pointer on the foreign function
|
|
let foreign_outptr = {
|
|
if tys.fn_ty.ret_ty.is_indirect() {
|
|
Some(llvm::LLVMGetParam(llwrapfn, next_foreign_arg(false)))
|
|
} else {
|
|
None
|
|
}
|
|
};
|
|
|
|
// Push Rust return pointer, using null if it will be unused.
|
|
let rust_uses_outptr =
|
|
type_of::return_uses_outptr(ccx, tys.fn_sig.output);
|
|
let return_alloca: Option<ValueRef>;
|
|
let llrust_ret_ty = tys.llsig.llret_ty;
|
|
let llrust_retptr_ty = llrust_ret_ty.ptr_to();
|
|
if rust_uses_outptr {
|
|
// Rust expects to use an outpointer. If the foreign fn
|
|
// also uses an outpointer, we can reuse it, but the types
|
|
// may vary, so cast first to the Rust type. If the
|
|
// foreign fn does NOT use an outpointer, we will have to
|
|
// alloca some scratch space on the stack.
|
|
match foreign_outptr {
|
|
Some(llforeign_outptr) => {
|
|
debug!("out pointer, foreign={}",
|
|
ccx.tn.val_to_str(llforeign_outptr));
|
|
let llrust_retptr =
|
|
llvm::LLVMBuildBitCast(builder,
|
|
llforeign_outptr,
|
|
llrust_ret_ty.ptr_to().to_ref(),
|
|
noname());
|
|
debug!("out pointer, foreign={} (casted)",
|
|
ccx.tn.val_to_str(llrust_retptr));
|
|
llrust_args.push(llrust_retptr);
|
|
return_alloca = None;
|
|
}
|
|
|
|
None => {
|
|
let slot = {
|
|
"return_alloca".with_c_str(
|
|
|s| llvm::LLVMBuildAlloca(builder,
|
|
llrust_ret_ty.to_ref(),
|
|
s))
|
|
};
|
|
debug!("out pointer, \
|
|
allocad={}, \
|
|
llrust_ret_ty={}, \
|
|
return_ty={}",
|
|
ccx.tn.val_to_str(slot),
|
|
ccx.tn.type_to_str(llrust_ret_ty),
|
|
tys.fn_sig.output.repr(tcx));
|
|
llrust_args.push(slot);
|
|
return_alloca = Some(slot);
|
|
}
|
|
}
|
|
} else {
|
|
// Rust does not expect an outpointer. If the foreign fn
|
|
// does use an outpointer, then we will do a store of the
|
|
// value that the Rust fn returns.
|
|
return_alloca = None;
|
|
};
|
|
|
|
// Push an (null) env pointer
|
|
let env_pointer = base::null_env_ptr(ccx);
|
|
debug!("env pointer={}", ccx.tn.val_to_str(env_pointer));
|
|
llrust_args.push(env_pointer);
|
|
|
|
// Build up the arguments to the call to the rust function.
|
|
// Careful to adapt for cases where the native convention uses
|
|
// a pointer and Rust does not or vice versa.
|
|
for i in range(0, tys.fn_sig.inputs.len()) {
|
|
let rust_ty = tys.fn_sig.inputs[i];
|
|
let llrust_ty = tys.llsig.llarg_tys[i];
|
|
let rust_indirect = type_of::arg_is_indirect(ccx, rust_ty);
|
|
let llforeign_arg_ty = tys.fn_ty.arg_tys[i];
|
|
let foreign_indirect = llforeign_arg_ty.is_indirect();
|
|
|
|
// skip padding
|
|
let foreign_index = next_foreign_arg(llforeign_arg_ty.pad.is_some());
|
|
let mut llforeign_arg = llvm::LLVMGetParam(llwrapfn, foreign_index);
|
|
|
|
debug!("llforeign_arg \\#{}: {}",
|
|
i, ccx.tn.val_to_str(llforeign_arg));
|
|
debug!("rust_indirect = {}, foreign_indirect = {}",
|
|
rust_indirect, foreign_indirect);
|
|
|
|
// Ensure that the foreign argument is indirect (by
|
|
// pointer). It makes adapting types easier, since we can
|
|
// always just bitcast pointers.
|
|
if !foreign_indirect {
|
|
let lltemp =
|
|
llvm::LLVMBuildAlloca(
|
|
builder, val_ty(llforeign_arg).to_ref(), noname());
|
|
llvm::LLVMBuildStore(
|
|
builder, llforeign_arg, lltemp);
|
|
llforeign_arg = lltemp;
|
|
}
|
|
|
|
// If the types in the ABI and the Rust types don't match,
|
|
// bitcast the llforeign_arg pointer so it matches the types
|
|
// Rust expects.
|
|
if llforeign_arg_ty.cast.is_some() {
|
|
assert!(!foreign_indirect);
|
|
llforeign_arg = llvm::LLVMBuildBitCast(
|
|
builder, llforeign_arg,
|
|
llrust_ty.ptr_to().to_ref(), noname());
|
|
}
|
|
|
|
let llrust_arg = if rust_indirect {
|
|
llforeign_arg
|
|
} else {
|
|
llvm::LLVMBuildLoad(builder, llforeign_arg, noname())
|
|
};
|
|
|
|
debug!("llrust_arg \\#{}: {}",
|
|
i, ccx.tn.val_to_str(llrust_arg));
|
|
llrust_args.push(llrust_arg);
|
|
}
|
|
|
|
// Perform the call itself
|
|
debug!("calling llrustfn = {}", ccx.tn.val_to_str(llrustfn));
|
|
let llrust_ret_val = llvm::LLVMBuildCall(builder, llrustfn, llrust_args.as_ptr(),
|
|
llrust_args.len() as c_uint, noname());
|
|
|
|
// Get the return value where the foreign fn expects it.
|
|
let llforeign_ret_ty = match tys.fn_ty.ret_ty.cast {
|
|
Some(ty) => ty,
|
|
None => tys.fn_ty.ret_ty.ty
|
|
};
|
|
match foreign_outptr {
|
|
None if !tys.ret_def => {
|
|
// Function returns `()` or `bot`, which in Rust is the LLVM
|
|
// type "{}" but in foreign ABIs is "Void".
|
|
llvm::LLVMBuildRetVoid(builder);
|
|
}
|
|
|
|
None if rust_uses_outptr => {
|
|
// Rust uses an outpointer, but the foreign ABI does not. Load.
|
|
let llrust_outptr = return_alloca.unwrap();
|
|
let llforeign_outptr_casted =
|
|
llvm::LLVMBuildBitCast(builder,
|
|
llrust_outptr,
|
|
llforeign_ret_ty.ptr_to().to_ref(),
|
|
noname());
|
|
let llforeign_retval =
|
|
llvm::LLVMBuildLoad(builder, llforeign_outptr_casted, noname());
|
|
llvm::LLVMBuildRet(builder, llforeign_retval);
|
|
}
|
|
|
|
None if llforeign_ret_ty != llrust_ret_ty => {
|
|
// Neither ABI uses an outpointer, but the types don't
|
|
// quite match. Must cast. Probably we should try and
|
|
// examine the types and use a concrete llvm cast, but
|
|
// right now we just use a temp memory location and
|
|
// bitcast the pointer, which is the same thing the
|
|
// old wrappers used to do.
|
|
let lltemp =
|
|
llvm::LLVMBuildAlloca(
|
|
builder, llforeign_ret_ty.to_ref(), noname());
|
|
let lltemp_casted =
|
|
llvm::LLVMBuildBitCast(builder,
|
|
lltemp,
|
|
llrust_ret_ty.ptr_to().to_ref(),
|
|
noname());
|
|
llvm::LLVMBuildStore(
|
|
builder, llrust_ret_val, lltemp_casted);
|
|
let llforeign_retval =
|
|
llvm::LLVMBuildLoad(builder, lltemp, noname());
|
|
llvm::LLVMBuildRet(builder, llforeign_retval);
|
|
}
|
|
|
|
None => {
|
|
// Neither ABI uses an outpointer, and the types
|
|
// match. Easy peasy.
|
|
llvm::LLVMBuildRet(builder, llrust_ret_val);
|
|
}
|
|
|
|
Some(llforeign_outptr) if !rust_uses_outptr => {
|
|
// Foreign ABI requires an out pointer, but Rust doesn't.
|
|
// Store Rust return value.
|
|
let llforeign_outptr_casted =
|
|
llvm::LLVMBuildBitCast(builder,
|
|
llforeign_outptr,
|
|
llrust_retptr_ty.to_ref(),
|
|
noname());
|
|
llvm::LLVMBuildStore(
|
|
builder, llrust_ret_val, llforeign_outptr_casted);
|
|
llvm::LLVMBuildRetVoid(builder);
|
|
}
|
|
|
|
Some(_) => {
|
|
// Both ABIs use outpointers. Easy peasy.
|
|
llvm::LLVMBuildRetVoid(builder);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
// General ABI Support
|
|
//
|
|
// This code is kind of a confused mess and needs to be reworked given
|
|
// the massive simplifications that have occurred.
|
|
|
|
pub fn link_name(ccx: &CrateContext, i: @ast::foreign_item) -> @str {
|
|
match attr::first_attr_value_str_by_name(i.attrs, "link_name") {
|
|
None => ccx.sess.str_of(i.ident),
|
|
Some(ln) => ln,
|
|
}
|
|
}
|
|
|
|
fn foreign_signature(ccx: &mut CrateContext, fn_sig: &ty::FnSig, arg_tys: &[ty::t])
|
|
-> LlvmSignature {
|
|
/*!
|
|
* The ForeignSignature is the LLVM types of the arguments/return type
|
|
* of a function. Note that these LLVM types are not quite the same
|
|
* as the LLVM types would be for a native Rust function because foreign
|
|
* functions just plain ignore modes. They also don't pass aggregate
|
|
* values by pointer like we do.
|
|
*/
|
|
|
|
let llarg_tys = arg_tys.map(|&arg| type_of(ccx, arg));
|
|
let llret_ty = type_of::type_of(ccx, fn_sig.output);
|
|
LlvmSignature {
|
|
llarg_tys: llarg_tys,
|
|
llret_ty: llret_ty,
|
|
sret: type_of::return_uses_outptr(ccx, fn_sig.output),
|
|
}
|
|
}
|
|
|
|
fn foreign_types_for_id(ccx: &mut CrateContext,
|
|
id: ast::NodeId) -> ForeignTypes {
|
|
foreign_types_for_fn_ty(ccx, ty::node_id_to_type(ccx.tcx, id))
|
|
}
|
|
|
|
fn foreign_types_for_fn_ty(ccx: &mut CrateContext,
|
|
ty: ty::t) -> ForeignTypes {
|
|
let fn_sig = match ty::get(ty).sty {
|
|
ty::ty_bare_fn(ref fn_ty) => fn_ty.sig.clone(),
|
|
_ => ccx.sess.bug("foreign_types_for_fn_ty called on non-function type")
|
|
};
|
|
let llsig = foreign_signature(ccx, &fn_sig, fn_sig.inputs);
|
|
let ret_def = !ty::type_is_voidish(ccx.tcx, fn_sig.output);
|
|
let fn_ty = cabi::compute_abi_info(ccx,
|
|
llsig.llarg_tys,
|
|
llsig.llret_ty,
|
|
ret_def);
|
|
debug!("foreign_types_for_fn_ty(\
|
|
ty={}, \
|
|
llsig={} -> {}, \
|
|
fn_ty={} -> {}, \
|
|
ret_def={}",
|
|
ty.repr(ccx.tcx),
|
|
ccx.tn.types_to_str(llsig.llarg_tys),
|
|
ccx.tn.type_to_str(llsig.llret_ty),
|
|
ccx.tn.types_to_str(fn_ty.arg_tys.map(|t| t.ty)),
|
|
ccx.tn.type_to_str(fn_ty.ret_ty.ty),
|
|
ret_def);
|
|
|
|
ForeignTypes {
|
|
fn_sig: fn_sig,
|
|
llsig: llsig,
|
|
ret_def: ret_def,
|
|
fn_ty: fn_ty
|
|
}
|
|
}
|
|
|
|
fn lltype_for_fn_from_foreign_types(tys: &ForeignTypes) -> Type {
|
|
let mut llargument_tys = ~[];
|
|
|
|
let ret_ty = tys.fn_ty.ret_ty;
|
|
let llreturn_ty = if ret_ty.is_indirect() {
|
|
llargument_tys.push(ret_ty.ty.ptr_to());
|
|
Type::void()
|
|
} else {
|
|
match ret_ty.cast {
|
|
Some(ty) => ty,
|
|
None => ret_ty.ty
|
|
}
|
|
};
|
|
|
|
for &arg_ty in tys.fn_ty.arg_tys.iter() {
|
|
// add padding
|
|
match arg_ty.pad {
|
|
Some(ty) => llargument_tys.push(ty),
|
|
None => ()
|
|
}
|
|
|
|
let llarg_ty = if arg_ty.is_indirect() {
|
|
arg_ty.ty.ptr_to()
|
|
} else {
|
|
match arg_ty.cast {
|
|
Some(ty) => ty,
|
|
None => arg_ty.ty
|
|
}
|
|
};
|
|
|
|
llargument_tys.push(llarg_ty);
|
|
}
|
|
|
|
if tys.fn_sig.variadic {
|
|
Type::variadic_func(llargument_tys, &llreturn_ty)
|
|
} else {
|
|
Type::func(llargument_tys, &llreturn_ty)
|
|
}
|
|
}
|
|
|
|
pub fn lltype_for_foreign_fn(ccx: &mut CrateContext, ty: ty::t) -> Type {
|
|
let fn_types = foreign_types_for_fn_ty(ccx, ty);
|
|
lltype_for_fn_from_foreign_types(&fn_types)
|
|
}
|
|
|
|
fn add_argument_attributes(tys: &ForeignTypes,
|
|
llfn: ValueRef) {
|
|
let mut i = 0;
|
|
|
|
if tys.fn_ty.ret_ty.is_indirect() {
|
|
match tys.fn_ty.ret_ty.attr {
|
|
Some(attr) => {
|
|
let llarg = get_param(llfn, i);
|
|
unsafe {
|
|
llvm::LLVMAddAttribute(llarg, attr as c_uint);
|
|
}
|
|
}
|
|
None => {}
|
|
}
|
|
|
|
i += 1;
|
|
}
|
|
|
|
for &arg_ty in tys.fn_ty.arg_tys.iter() {
|
|
// skip padding
|
|
if arg_ty.pad.is_some() { i += 1; }
|
|
|
|
match arg_ty.attr {
|
|
Some(attr) => {
|
|
let llarg = get_param(llfn, i);
|
|
unsafe {
|
|
llvm::LLVMAddAttribute(llarg, attr as c_uint);
|
|
}
|
|
}
|
|
None => ()
|
|
}
|
|
|
|
i += 1;
|
|
}
|
|
}
|