1 // Copyright 2012-2014 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 // trans.rs: Translate the completed AST to the LLVM IR.
13 // Some functions here, such as trans_block and trans_expr, return a value --
14 // the result of the translation to LLVM -- while others, such as trans_fn,
15 // trans_impl, and trans_item, are called only for the side effect of adding a
16 // particular definition to the LLVM IR output we're producing.
18 // Hopefully useful general knowledge about trans:
20 // * There's no way to find out the Ty type of a ValueRef. Doing so
21 // would be "trying to get the eggs out of an omelette" (credit:
22 // pcwalton). You can, instead, find out its TypeRef by calling val_ty,
23 // but one TypeRef corresponds to many `Ty`s; for instance, tup(int, int,
24 // int) and rec(x=int, y=int, z=int) will have the same TypeRef.
26 #![allow(non_camel_case_types)]
28 pub use self::ValueOrigin::*;
29 pub use self::scalar_type::*;
31 use super::CrateTranslation;
32 use super::ModuleTranslation;
34 use back::link::{mangle_exported_name};
35 use back::{link, abi};
37 use llvm::{BasicBlockRef, Linkage, ValueRef, Vector, get_param};
39 use metadata::{csearch, encoder, loader};
40 use middle::astencode;
42 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
44 use middle::weak_lang_items;
45 use middle::subst::{Subst, Substs};
46 use middle::ty::{self, Ty, UnboxedClosureTyper};
47 use session::config::{self, NoDebugInfo, FullDebugInfo};
52 use trans::builder::{Builder, noname};
54 use trans::cleanup::CleanupMethods;
57 use trans::common::{Block, C_bool, C_bytes_in_context, C_i32, C_integral};
58 use trans::common::{C_null, C_struct_in_context, C_u64, C_u8, C_undef};
59 use trans::common::{CrateContext, ExternMap, FunctionContext};
60 use trans::common::{NodeInfo, Result};
61 use trans::common::{node_id_type, return_type_is_void};
62 use trans::common::{tydesc_info, type_is_immediate};
63 use trans::common::{type_is_zero_size, val_ty};
66 use trans::context::SharedCrateContext;
67 use trans::controlflow;
76 use trans::machine::{llsize_of, llsize_of_real};
78 use trans::monomorphize;
80 use trans::type_::Type;
82 use trans::type_of::*;
83 use trans::value::Value;
84 use util::common::indenter;
85 use util::ppaux::{Repr, ty_to_string};
86 use util::sha2::Sha256;
87 use util::nodemap::NodeMap;
89 use arena::TypedArena;
90 use libc::{c_uint, uint64_t};
91 use std::c_str::ToCStr;
92 use std::cell::{Cell, RefCell};
93 use std::collections::HashSet;
96 use std::{i8, i16, i32, i64};
97 use syntax::abi::{Rust, RustCall, RustIntrinsic, Abi};
98 use syntax::ast_util::local_def;
99 use syntax::attr::AttrMetaMethods;
101 use syntax::codemap::Span;
102 use syntax::parse::token::InternedString;
103 use syntax::visit::Visitor;
105 use syntax::{ast, ast_util, ast_map};
108 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
113 pub fn with_insn_ctxt<F>(blk: F) where
114 F: FnOnce(&[&'static str]),
116 TASK_LOCAL_INSN_KEY.with(move |slot| {
117 slot.borrow().as_ref().map(move |s| blk(s.as_slice()));
121 pub fn init_insn_ctxt() {
122 TASK_LOCAL_INSN_KEY.with(|slot| {
123 *slot.borrow_mut() = Some(Vec::new());
127 pub struct _InsnCtxt {
128 _cannot_construct_outside_of_this_module: ()
132 impl Drop for _InsnCtxt {
134 TASK_LOCAL_INSN_KEY.with(|slot| {
135 match slot.borrow_mut().as_mut() {
136 Some(ctx) => { ctx.pop(); }
143 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
144 debug!("new InsnCtxt: {}", s);
145 TASK_LOCAL_INSN_KEY.with(|slot| {
146 match slot.borrow_mut().as_mut() {
147 Some(ctx) => ctx.push(s),
151 _InsnCtxt { _cannot_construct_outside_of_this_module: () }
154 pub struct StatRecorder<'a, 'tcx: 'a> {
155 ccx: &'a CrateContext<'a, 'tcx>,
156 name: Option<String>,
160 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
161 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
162 -> StatRecorder<'a, 'tcx> {
163 let istart = ccx.stats().n_llvm_insns.get();
173 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
175 if self.ccx.sess().trans_stats() {
176 let iend = self.ccx.stats().n_llvm_insns.get();
177 self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
178 iend - self.istart));
179 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
180 // Reset LLVM insn count to avoid compound costs.
181 self.ccx.stats().n_llvm_insns.set(self.istart);
186 // only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
187 pub fn decl_fn(ccx: &CrateContext, name: &str, cc: llvm::CallConv,
188 ty: Type, output: ty::FnOutput) -> ValueRef {
190 let llfn: ValueRef = name.with_c_str(|buf| {
192 llvm::LLVMGetOrInsertFunction(ccx.llmod(), buf, ty.to_ref())
196 // diverging functions may unwind, but can never return normally
197 if output == ty::FnDiverging {
198 llvm::SetFunctionAttribute(llfn, llvm::NoReturnAttribute);
201 if ccx.tcx().sess.opts.cg.no_redzone
202 .unwrap_or(ccx.tcx().sess.target.target.options.disable_redzone) {
203 llvm::SetFunctionAttribute(llfn, llvm::NoRedZoneAttribute)
206 llvm::SetFunctionCallConv(llfn, cc);
207 // Function addresses in Rust are never significant, allowing functions to be merged.
208 llvm::SetUnnamedAddr(llfn, true);
210 if ccx.is_split_stack_supported() && !ccx.sess().opts.cg.no_stack_check {
211 set_split_stack(llfn);
217 // only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
218 pub fn decl_cdecl_fn(ccx: &CrateContext,
221 output: Ty) -> ValueRef {
222 decl_fn(ccx, name, llvm::CCallConv, ty, ty::FnConverging(output))
225 // only use this for foreign function ABIs and glue, use `get_extern_rust_fn` for Rust functions
226 pub fn get_extern_fn(ccx: &CrateContext,
227 externs: &mut ExternMap,
233 match externs.get(name) {
234 Some(n) => return *n,
237 let f = decl_fn(ccx, name, cc, ty, ty::FnConverging(output));
238 externs.insert(name.to_string(), f);
242 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>,
243 name: &str, did: ast::DefId) -> ValueRef {
244 match ccx.externs().borrow().get(name) {
245 Some(n) => return *n,
249 let f = decl_rust_fn(ccx, fn_ty, name);
251 csearch::get_item_attrs(&ccx.sess().cstore, did, |attrs| {
252 set_llvm_fn_attrs(ccx, attrs[], f)
255 ccx.externs().borrow_mut().insert(name.to_string(), f);
259 pub fn self_type_for_unboxed_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
260 closure_id: ast::DefId,
264 let unboxed_closure_kind = ccx.tcx().unboxed_closure_kind(closure_id);
265 match unboxed_closure_kind {
266 ty::FnUnboxedClosureKind => {
267 ty::mk_imm_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
269 ty::FnMutUnboxedClosureKind => {
270 ty::mk_mut_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
272 ty::FnOnceUnboxedClosureKind => fn_ty
276 pub fn kind_for_unboxed_closure(ccx: &CrateContext, closure_id: ast::DefId)
277 -> ty::UnboxedClosureKind {
278 let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
279 (*unboxed_closures)[closure_id].kind
282 pub fn decl_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
283 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
284 let fn_ty = monomorphize::normalize_associated_type(ccx.tcx(), &fn_ty);
286 let (inputs, output, abi, env) = match fn_ty.sty {
287 ty::ty_bare_fn(_, ref f) => {
288 (f.sig.0.inputs.clone(), f.sig.0.output, f.abi, None)
290 ty::ty_closure(ref f) => {
291 (f.sig.0.inputs.clone(), f.sig.0.output, f.abi, Some(Type::i8p(ccx)))
293 ty::ty_unboxed_closure(closure_did, _, substs) => {
294 let typer = common::NormalizingUnboxedClosureTyper::new(ccx.tcx());
295 let function_type = typer.unboxed_closure_type(closure_did, substs);
296 let self_type = self_type_for_unboxed_closure(ccx, closure_did, fn_ty);
297 let llenvironment_type = type_of_explicit_arg(ccx, self_type);
298 debug!("decl_rust_fn: function_type={} self_type={}",
299 function_type.repr(ccx.tcx()),
300 self_type.repr(ccx.tcx()));
301 (function_type.sig.0.inputs,
302 function_type.sig.0.output,
304 Some(llenvironment_type))
306 _ => panic!("expected closure or fn")
309 let llfty = type_of_rust_fn(ccx, env, inputs[], output, abi);
310 debug!("decl_rust_fn(input count={},type={})",
312 ccx.tn().type_to_string(llfty));
314 let llfn = decl_fn(ccx, name, llvm::CCallConv, llfty, output);
315 let attrs = get_fn_llvm_attributes(ccx, fn_ty);
316 attrs.apply_llfn(llfn);
321 pub fn decl_internal_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
322 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
323 let llfn = decl_rust_fn(ccx, fn_ty, name);
324 llvm::SetLinkage(llfn, llvm::InternalLinkage);
328 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: ast::DefId,
329 t: Ty<'tcx>) -> ValueRef {
330 let name = csearch::get_symbol(&ccx.sess().cstore, did);
331 let ty = type_of(ccx, t);
332 match ccx.externs().borrow_mut().get(&name) {
333 Some(n) => return *n,
337 let c = name.with_c_str(|buf| {
338 llvm::LLVMAddGlobal(ccx.llmod(), ty.to_ref(), buf)
340 // Thread-local statics in some other crate need to *always* be linked
341 // against in a thread-local fashion, so we need to be sure to apply the
342 // thread-local attribute locally if it was present remotely. If we
343 // don't do this then linker errors can be generated where the linker
344 // complains that one object files has a thread local version of the
345 // symbol and another one doesn't.
346 ty::each_attr(ccx.tcx(), did, |attr| {
347 if attr.check_name("thread_local") {
348 llvm::set_thread_local(c, true);
352 ccx.externs().borrow_mut().insert(name.to_string(), c);
357 // Returns a pointer to the body for the box. The box may be an opaque
358 // box. The result will be casted to the type of body_t, if it is statically
360 pub fn at_box_body<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
361 body_t: Ty<'tcx>, boxptr: ValueRef) -> ValueRef {
362 let _icx = push_ctxt("at_box_body");
364 let ty = Type::at_box(ccx, type_of(ccx, body_t));
365 let boxptr = PointerCast(bcx, boxptr, ty.ptr_to());
366 GEPi(bcx, boxptr, &[0u, abi::BOX_FIELD_BODY])
369 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
370 info_ty: Ty<'tcx>, it: LangItem) -> ast::DefId {
371 match bcx.tcx().lang_items.require(it) {
374 bcx.sess().fatal(format!("allocation of `{}` {}",
375 bcx.ty_to_string(info_ty),
381 // The following malloc_raw_dyn* functions allocate a box to contain
382 // a given type, but with a potentially dynamic size.
384 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
389 -> Result<'blk, 'tcx> {
390 let _icx = push_ctxt("malloc_raw_exchange");
393 let r = callee::trans_lang_call(bcx,
394 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
398 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
401 // Type descriptor and type glue stuff
403 pub fn get_tydesc<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
404 t: Ty<'tcx>) -> Rc<tydesc_info<'tcx>> {
405 match ccx.tydescs().borrow().get(&t) {
406 Some(inf) => return inf.clone(),
410 ccx.stats().n_static_tydescs.set(ccx.stats().n_static_tydescs.get() + 1u);
411 let inf = Rc::new(glue::declare_tydesc(ccx, t));
413 ccx.tydescs().borrow_mut().insert(t, inf.clone());
417 #[allow(dead_code)] // useful
418 pub fn set_optimize_for_size(f: ValueRef) {
419 llvm::SetFunctionAttribute(f, llvm::OptimizeForSizeAttribute)
422 pub fn set_no_inline(f: ValueRef) {
423 llvm::SetFunctionAttribute(f, llvm::NoInlineAttribute)
426 #[allow(dead_code)] // useful
427 pub fn set_no_unwind(f: ValueRef) {
428 llvm::SetFunctionAttribute(f, llvm::NoUnwindAttribute)
431 // Tell LLVM to emit the information necessary to unwind the stack for the
433 pub fn set_uwtable(f: ValueRef) {
434 llvm::SetFunctionAttribute(f, llvm::UWTableAttribute)
437 pub fn set_inline_hint(f: ValueRef) {
438 llvm::SetFunctionAttribute(f, llvm::InlineHintAttribute)
441 pub fn set_llvm_fn_attrs(ccx: &CrateContext, attrs: &[ast::Attribute], llfn: ValueRef) {
443 // Set the inline hint if there is one
444 match find_inline_attr(attrs) {
445 InlineHint => set_inline_hint(llfn),
446 InlineAlways => set_always_inline(llfn),
447 InlineNever => set_no_inline(llfn),
448 InlineNone => { /* fallthrough */ }
451 for attr in attrs.iter() {
453 match attr.name().get() {
454 "no_stack_check" => unset_split_stack(llfn),
455 "no_split_stack" => {
456 unset_split_stack(llfn);
457 ccx.sess().span_warn(attr.span,
458 "no_split_stack is a deprecated synonym for no_stack_check");
461 llvm::LLVMAddFunctionAttribute(llfn,
462 llvm::FunctionIndex as c_uint,
463 llvm::ColdAttribute as uint64_t)
468 attr::mark_used(attr);
473 pub fn set_always_inline(f: ValueRef) {
474 llvm::SetFunctionAttribute(f, llvm::AlwaysInlineAttribute)
477 pub fn set_split_stack(f: ValueRef) {
478 "split-stack".with_c_str(|buf| {
479 unsafe { llvm::LLVMAddFunctionAttrString(f, llvm::FunctionIndex as c_uint, buf); }
483 pub fn unset_split_stack(f: ValueRef) {
484 "split-stack".with_c_str(|buf| {
485 unsafe { llvm::LLVMRemoveFunctionAttrString(f, llvm::FunctionIndex as c_uint, buf); }
489 // Double-check that we never ask LLVM to declare the same symbol twice. It
490 // silently mangles such symbols, breaking our linkage model.
491 pub fn note_unique_llvm_symbol(ccx: &CrateContext, sym: String) {
492 if ccx.all_llvm_symbols().borrow().contains(&sym) {
493 ccx.sess().bug(format!("duplicate LLVM symbol: {}", sym)[]);
495 ccx.all_llvm_symbols().borrow_mut().insert(sym);
499 pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
502 parent_id: ast::DefId,
503 substs: &subst::Substs<'tcx>)
505 let _icx = push_ctxt("trans_res_dtor");
506 let did = inline::maybe_instantiate_inline(ccx, did);
508 if !substs.types.is_empty() {
509 assert_eq!(did.krate, ast::LOCAL_CRATE);
511 // Since we're in trans we don't care for any region parameters
512 let substs = subst::Substs::erased(substs.types.clone());
514 let (val, _, _) = monomorphize::monomorphic_fn(ccx, did, &substs, None);
517 } else if did.krate == ast::LOCAL_CRATE {
518 get_item_val(ccx, did.node)
521 let name = csearch::get_symbol(&ccx.sess().cstore, did);
522 let class_ty = ty::lookup_item_type(tcx, parent_id).ty.subst(tcx, substs);
523 let llty = type_of_dtor(ccx, class_ty);
524 let dtor_ty = ty::mk_ctor_fn(ccx.tcx(),
526 &[glue::get_drop_glue_type(ccx, t)],
527 ty::mk_nil(ccx.tcx()));
529 &mut *ccx.externs().borrow_mut(),
537 // Structural comparison: a rather involved form of glue.
538 pub fn maybe_name_value(cx: &CrateContext, v: ValueRef, s: &str) {
539 if cx.sess().opts.cg.save_temps {
542 llvm::LLVMSetValueName(v, buf)
549 // Used only for creating scalar comparison glue.
551 pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
553 pub fn compare_scalar_types<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
558 -> Result<'blk, 'tcx> {
559 let f = |&: a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op));
562 ty::ty_tup(ref tys) if tys.is_empty() => f(nil_type),
563 ty::ty_bool | ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
564 ty::ty_ptr(mt) if common::type_is_sized(cx.tcx(), mt.ty) => f(unsigned_int),
565 ty::ty_int(_) => f(signed_int),
566 ty::ty_float(_) => f(floating_point),
567 // Should never get here, because t is scalar.
568 _ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
573 // A helper function to do the actual comparison of scalar values.
574 pub fn compare_scalar_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
580 let _icx = push_ctxt("compare_scalar_values");
581 fn die(cx: Block) -> ! {
582 cx.sess().bug("compare_scalar_values: must be a comparison operator");
586 // We don't need to do actual comparisons for nil.
587 // () == () holds but () < () does not.
589 ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(cx.ccx(), true),
590 ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(cx.ccx(), false),
591 // refinements would be nice
597 ast::BiEq => llvm::RealOEQ,
598 ast::BiNe => llvm::RealUNE,
599 ast::BiLt => llvm::RealOLT,
600 ast::BiLe => llvm::RealOLE,
601 ast::BiGt => llvm::RealOGT,
602 ast::BiGe => llvm::RealOGE,
605 return FCmp(cx, cmp, lhs, rhs);
609 ast::BiEq => llvm::IntEQ,
610 ast::BiNe => llvm::IntNE,
611 ast::BiLt => llvm::IntSLT,
612 ast::BiLe => llvm::IntSLE,
613 ast::BiGt => llvm::IntSGT,
614 ast::BiGe => llvm::IntSGE,
617 return ICmp(cx, cmp, lhs, rhs);
621 ast::BiEq => llvm::IntEQ,
622 ast::BiNe => llvm::IntNE,
623 ast::BiLt => llvm::IntULT,
624 ast::BiLe => llvm::IntULE,
625 ast::BiGt => llvm::IntUGT,
626 ast::BiGe => llvm::IntUGE,
629 return ICmp(cx, cmp, lhs, rhs);
634 pub fn compare_simd_types<'blk, 'tcx>(
635 cx: Block<'blk, 'tcx>,
644 // The comparison operators for floating point vectors are challenging.
645 // LLVM outputs a `< size x i1 >`, but if we perform a sign extension
646 // then bitcast to a floating point vector, the result will be `-NaN`
647 // for each truth value. Because of this they are unsupported.
648 cx.sess().bug("compare_simd_types: comparison operators \
649 not supported for floating point SIMD types")
651 ty::ty_uint(_) | ty::ty_int(_) => {
653 ast::BiEq => llvm::IntEQ,
654 ast::BiNe => llvm::IntNE,
655 ast::BiLt => llvm::IntSLT,
656 ast::BiLe => llvm::IntSLE,
657 ast::BiGt => llvm::IntSGT,
658 ast::BiGe => llvm::IntSGE,
659 _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
661 let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
662 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
663 // to get the correctly sized type. This will compile to a single instruction
664 // once the IR is converted to assembly if the SIMD instruction is supported
665 // by the target architecture.
666 SExt(cx, ICmp(cx, cmp, lhs, rhs), return_ty)
668 _ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
672 pub type val_and_ty_fn<'a, 'blk, 'tcx> =
673 |Block<'blk, 'tcx>, ValueRef, Ty<'tcx>|: 'a -> Block<'blk, 'tcx>;
675 // Iterates through the elements of a structural type.
676 pub fn iter_structural_ty<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
679 f: val_and_ty_fn<'a, 'blk, 'tcx>)
680 -> Block<'blk, 'tcx> {
681 let _icx = push_ctxt("iter_structural_ty");
683 fn iter_variant<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
684 repr: &adt::Repr<'tcx>,
686 variant: &ty::VariantInfo<'tcx>,
687 substs: &subst::Substs<'tcx>,
688 f: val_and_ty_fn<'a, 'blk, 'tcx>)
689 -> Block<'blk, 'tcx> {
690 let _icx = push_ctxt("iter_variant");
694 for (i, &arg) in variant.args.iter().enumerate() {
696 adt::trans_field_ptr(cx, repr, av, variant.disr_val, i),
697 arg.subst(tcx, substs));
702 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
705 let data = GEPi(cx, av, &[0, abi::FAT_PTR_ADDR]);
706 let info = GEPi(cx, av, &[0, abi::FAT_PTR_EXTRA]);
707 (Load(cx, data), Some(Load(cx, info)))
712 ty::ty_struct(..) => {
713 let repr = adt::represent_type(cx.ccx(), t);
714 expr::with_field_tys(cx.tcx(), t, None, |discr, field_tys| {
715 for (i, field_ty) in field_tys.iter().enumerate() {
716 let field_ty = field_ty.mt.ty;
717 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
719 let val = if common::type_is_sized(cx.tcx(), field_ty) {
722 let boxed_ty = ty::mk_open(cx.tcx(), field_ty);
723 let scratch = datum::rvalue_scratch_datum(cx, boxed_ty, "__fat_ptr_iter");
724 Store(cx, llfld_a, GEPi(cx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
725 Store(cx, info.unwrap(), GEPi(cx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
728 cx = f(cx, val, field_ty);
732 ty::ty_unboxed_closure(def_id, _, substs) => {
733 let repr = adt::represent_type(cx.ccx(), t);
734 let typer = common::NormalizingUnboxedClosureTyper::new(cx.tcx());
735 let upvars = typer.unboxed_closure_upvars(def_id, substs).unwrap();
736 for (i, upvar) in upvars.iter().enumerate() {
737 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
738 cx = f(cx, llupvar, upvar.ty);
741 ty::ty_vec(_, Some(n)) => {
742 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
743 let unit_ty = ty::sequence_element_type(cx.tcx(), t);
744 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
746 ty::ty_tup(ref args) => {
747 let repr = adt::represent_type(cx.ccx(), t);
748 for (i, arg) in args.iter().enumerate() {
749 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
750 cx = f(cx, llfld_a, *arg);
753 ty::ty_enum(tid, substs) => {
757 let repr = adt::represent_type(ccx, t);
758 let variants = ty::enum_variants(ccx.tcx(), tid);
759 let n_variants = (*variants).len();
761 // NB: we must hit the discriminant first so that structural
762 // comparison know not to proceed when the discriminants differ.
764 match adt::trans_switch(cx, &*repr, av) {
765 (_match::Single, None) => {
766 cx = iter_variant(cx, &*repr, av, &*(*variants)[0],
769 (_match::Switch, Some(lldiscrim_a)) => {
770 cx = f(cx, lldiscrim_a, cx.tcx().types.int);
771 let unr_cx = fcx.new_temp_block("enum-iter-unr");
773 let llswitch = Switch(cx, lldiscrim_a, unr_cx.llbb,
775 let next_cx = fcx.new_temp_block("enum-iter-next");
777 for variant in (*variants).iter() {
780 format!("enum-iter-variant-{}",
781 variant.disr_val.to_string()[])
783 match adt::trans_case(cx, &*repr, variant.disr_val) {
784 _match::SingleResult(r) => {
785 AddCase(llswitch, r.val, variant_cx.llbb)
787 _ => ccx.sess().unimpl("value from adt::trans_case \
788 in iter_structural_ty")
791 iter_variant(variant_cx,
797 Br(variant_cx, next_cx.llbb);
801 _ => ccx.sess().unimpl("value from adt::trans_switch \
802 in iter_structural_ty")
806 cx.sess().unimpl(format!("type in iter_structural_ty: {}",
807 ty_to_string(cx.tcx(), t))[])
813 pub fn cast_shift_expr_rhs(cx: Block,
818 cast_shift_rhs(op, lhs, rhs,
819 |a,b| Trunc(cx, a, b),
820 |a,b| ZExt(cx, a, b))
823 pub fn cast_shift_const_rhs(op: ast::BinOp,
824 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
825 cast_shift_rhs(op, lhs, rhs,
826 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
827 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
830 pub fn cast_shift_rhs<F, G>(op: ast::BinOp,
836 F: FnOnce(ValueRef, Type) -> ValueRef,
837 G: FnOnce(ValueRef, Type) -> ValueRef,
839 // Shifts may have any size int on the rhs
841 if ast_util::is_shift_binop(op) {
842 let mut rhs_llty = val_ty(rhs);
843 let mut lhs_llty = val_ty(lhs);
844 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
845 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
846 let rhs_sz = llvm::LLVMGetIntTypeWidth(rhs_llty.to_ref());
847 let lhs_sz = llvm::LLVMGetIntTypeWidth(lhs_llty.to_ref());
850 } else if lhs_sz > rhs_sz {
851 // FIXME (#1877: If shifting by negative
852 // values becomes not undefined then this is wrong.
863 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
864 cx: Block<'blk, 'tcx>,
870 -> Block<'blk, 'tcx> {
871 let (zero_text, overflow_text) = if divrem == ast::BiDiv {
872 ("attempted to divide by zero",
873 "attempted to divide with overflow")
875 ("attempted remainder with a divisor of zero",
876 "attempted remainder with overflow")
878 let (is_zero, is_signed) = match rhs_t.sty {
880 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0u64, false);
881 (ICmp(cx, llvm::IntEQ, rhs, zero), true)
884 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0u64, false);
885 (ICmp(cx, llvm::IntEQ, rhs, zero), false)
888 cx.sess().bug(format!("fail-if-zero on unexpected type: {}",
889 ty_to_string(cx.tcx(), rhs_t))[]);
892 let bcx = with_cond(cx, is_zero, |bcx| {
893 controlflow::trans_fail(bcx, span, InternedString::new(zero_text))
896 // To quote LLVM's documentation for the sdiv instruction:
898 // Division by zero leads to undefined behavior. Overflow also leads
899 // to undefined behavior; this is a rare case, but can occur, for
900 // example, by doing a 32-bit division of -2147483648 by -1.
902 // In order to avoid undefined behavior, we perform runtime checks for
903 // signed division/remainder which would trigger overflow. For unsigned
904 // integers, no action beyond checking for zero need be taken.
906 let (llty, min) = match rhs_t.sty {
908 let llty = Type::int_from_ty(cx.ccx(), t);
910 ast::TyI if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
911 ast::TyI => i64::MIN as u64,
912 ast::TyI8 => i8::MIN as u64,
913 ast::TyI16 => i16::MIN as u64,
914 ast::TyI32 => i32::MIN as u64,
915 ast::TyI64 => i64::MIN as u64,
921 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
922 C_integral(llty, -1, false));
923 with_cond(bcx, minus_one, |bcx| {
924 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
925 C_integral(llty, min, true));
926 with_cond(bcx, is_min, |bcx| {
927 controlflow::trans_fail(bcx, span,
928 InternedString::new(overflow_text))
936 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
937 did: ast::DefId, t: Ty<'tcx>) -> ValueRef {
938 let name = csearch::get_symbol(&ccx.sess().cstore, did);
940 ty::ty_bare_fn(_, ref fn_ty) => {
941 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
943 get_extern_rust_fn(ccx, t, name[], did)
946 ccx.sess().bug("unexpected intrinsic in trans_external_path")
949 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t,
954 ty::ty_closure(_) => {
955 get_extern_rust_fn(ccx, t, name[], did)
958 get_extern_const(ccx, did, t)
963 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
967 call_info: Option<NodeInfo>)
968 -> (ValueRef, Block<'blk, 'tcx>) {
969 let _icx = push_ctxt("invoke_");
970 if bcx.unreachable.get() {
971 return (C_null(Type::i8(bcx.ccx())), bcx);
974 let attributes = get_fn_llvm_attributes(bcx.ccx(), fn_ty);
976 match bcx.opt_node_id {
978 debug!("invoke at ???");
981 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
985 if need_invoke(bcx) {
986 debug!("invoking {} at {}", bcx.val_to_string(llfn), bcx.llbb);
987 for &llarg in llargs.iter() {
988 debug!("arg: {}", bcx.val_to_string(llarg));
990 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
991 let landing_pad = bcx.fcx.get_landing_pad();
994 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
995 None => debuginfo::clear_source_location(bcx.fcx)
998 let llresult = Invoke(bcx,
1004 return (llresult, normal_bcx);
1006 debug!("calling {} at {}", bcx.val_to_string(llfn), bcx.llbb);
1007 for &llarg in llargs.iter() {
1008 debug!("arg: {}", bcx.val_to_string(llarg));
1012 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
1013 None => debuginfo::clear_source_location(bcx.fcx)
1016 let llresult = Call(bcx, llfn, llargs[], Some(attributes));
1017 return (llresult, bcx);
1021 pub fn need_invoke(bcx: Block) -> bool {
1022 if bcx.sess().no_landing_pads() {
1026 // Avoid using invoke if we are already inside a landing pad.
1031 bcx.fcx.needs_invoke()
1034 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1035 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
1036 let _icx = push_ctxt("load_if_immediate");
1037 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
1041 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1042 /// differs from the type used for SSA values. Also handles various special cases where the type
1043 /// gives us better information about what we are loading.
1044 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1045 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
1046 if type_is_zero_size(cx.ccx(), t) {
1047 C_undef(type_of::type_of(cx.ccx(), t))
1048 } else if ty::type_is_bool(t) {
1049 Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
1050 } else if ty::type_is_char(t) {
1051 // a char is a Unicode codepoint, and so takes values from 0
1052 // to 0x10FFFF inclusive only.
1053 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1059 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1060 /// differs from the type used for SSA values.
1061 pub fn store_ty(cx: Block, v: ValueRef, dst: ValueRef, t: Ty) {
1062 if ty::type_is_bool(t) {
1063 Store(cx, ZExt(cx, v, Type::i8(cx.ccx())), dst);
1069 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &ast::Local)
1070 -> Block<'blk, 'tcx> {
1071 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1072 let _indenter = indenter();
1073 let _icx = push_ctxt("init_local");
1074 _match::store_local(bcx, local)
1077 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1079 llbb: BasicBlockRef)
1080 -> Block<'blk, 'tcx> {
1081 common::BlockS::new(llbb, is_lpad, None, fcx)
1084 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
1087 -> Block<'blk, 'tcx> where
1088 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
1090 let _icx = push_ctxt("with_cond");
1092 let next_cx = fcx.new_temp_block("next");
1093 let cond_cx = fcx.new_temp_block("cond");
1094 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb);
1095 let after_cx = f(cond_cx);
1096 if !after_cx.terminated.get() {
1097 Br(after_cx, next_cx.llbb);
1102 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1103 if cx.sess().opts.optimize == config::No {
1107 let _icx = push_ctxt("lifetime_start");
1110 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1111 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1112 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1113 Call(cx, lifetime_start, &[llsize, ptr], None);
1116 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1117 if cx.sess().opts.optimize == config::No {
1121 let _icx = push_ctxt("lifetime_end");
1124 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1125 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1126 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1127 Call(cx, lifetime_end, &[llsize, ptr], None);
1130 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1131 let _icx = push_ctxt("call_memcpy");
1133 let key = match ccx.sess().target.target.target_word_size[] {
1134 "32" => "llvm.memcpy.p0i8.p0i8.i32",
1135 "64" => "llvm.memcpy.p0i8.p0i8.i64",
1136 tws => panic!("Unsupported target word size for memcpy: {}", tws),
1138 let memcpy = ccx.get_intrinsic(&key);
1139 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1140 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1141 let size = IntCast(cx, n_bytes, ccx.int_type());
1142 let align = C_i32(ccx, align as i32);
1143 let volatile = C_bool(ccx, false);
1144 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None);
1147 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1148 dst: ValueRef, src: ValueRef,
1150 let _icx = push_ctxt("memcpy_ty");
1151 let ccx = bcx.ccx();
1152 if ty::type_is_structural(t) {
1153 let llty = type_of::type_of(ccx, t);
1154 let llsz = llsize_of(ccx, llty);
1155 let llalign = type_of::align_of(ccx, t);
1156 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1158 store_ty(bcx, Load(bcx, src), dst, t);
1162 pub fn zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1163 if cx.unreachable.get() { return; }
1164 let _icx = push_ctxt("zero_mem");
1166 memzero(&B(bcx), llptr, t);
1169 // Always use this function instead of storing a zero constant to the memory
1170 // in question. If you store a zero constant, LLVM will drown in vreg
1171 // allocation for large data structures, and the generated code will be
1172 // awful. (A telltale sign of this is large quantities of
1173 // `mov [byte ptr foo],0` in the generated code.)
1174 fn memzero<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>) {
1175 let _icx = push_ctxt("memzero");
1178 let llty = type_of::type_of(ccx, ty);
1180 let intrinsic_key = match ccx.sess().target.target.target_word_size[] {
1181 "32" => "llvm.memset.p0i8.i32",
1182 "64" => "llvm.memset.p0i8.i64",
1183 tws => panic!("Unsupported target word size for memset: {}", tws),
1186 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1187 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1188 let llzeroval = C_u8(ccx, 0);
1189 let size = machine::llsize_of(ccx, llty);
1190 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1191 let volatile = C_bool(ccx, false);
1192 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1195 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1196 let _icx = push_ctxt("alloc_ty");
1197 let ccx = bcx.ccx();
1198 let ty = type_of::type_of(ccx, t);
1199 assert!(!ty::type_has_params(t));
1200 let val = alloca(bcx, ty, name);
1204 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1205 let p = alloca_no_lifetime(cx, ty, name);
1206 call_lifetime_start(cx, p);
1210 pub fn alloca_no_lifetime(cx: Block, ty: Type, name: &str) -> ValueRef {
1211 let _icx = push_ctxt("alloca");
1212 if cx.unreachable.get() {
1214 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1217 debuginfo::clear_source_location(cx.fcx);
1218 Alloca(cx, ty, name)
1221 pub fn alloca_zeroed<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>,
1222 name: &str) -> ValueRef {
1223 let llty = type_of::type_of(cx.ccx(), ty);
1224 if cx.unreachable.get() {
1226 return llvm::LLVMGetUndef(llty.ptr_to().to_ref());
1229 let p = alloca_no_lifetime(cx, llty, name);
1230 let b = cx.fcx.ccx.builder();
1231 b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
1236 pub fn arrayalloca(cx: Block, ty: Type, v: ValueRef) -> ValueRef {
1237 let _icx = push_ctxt("arrayalloca");
1238 if cx.unreachable.get() {
1240 return llvm::LLVMGetUndef(ty.to_ref());
1243 debuginfo::clear_source_location(cx.fcx);
1244 let p = ArrayAlloca(cx, ty, v);
1245 call_lifetime_start(cx, p);
1249 // Creates the alloca slot which holds the pointer to the slot for the final return value
1250 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1251 output_type: Ty<'tcx>) -> ValueRef {
1252 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1254 // We create an alloca to hold a pointer of type `output_type`
1255 // which will hold the pointer to the right alloca which has the
1257 if fcx.needs_ret_allocas {
1258 // Let's create the stack slot
1259 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1261 // and if we're using an out pointer, then store that in our newly made slot
1262 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1263 let outptr = get_param(fcx.llfn, 0);
1265 let b = fcx.ccx.builder();
1266 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1267 b.store(outptr, slot);
1272 // But if there are no nested returns, we skip the indirection and have a single
1275 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1276 get_param(fcx.llfn, 0)
1278 AllocaFcx(fcx, lloutputtype, "sret_slot")
1283 struct FindNestedReturn {
1287 impl FindNestedReturn {
1288 fn new() -> FindNestedReturn {
1289 FindNestedReturn { found: false }
1293 impl<'v> Visitor<'v> for FindNestedReturn {
1294 fn visit_expr(&mut self, e: &ast::Expr) {
1296 ast::ExprRet(..) => {
1299 _ => visit::walk_expr(self, e)
1304 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1305 let blk = match tcx.map.find(id) {
1306 Some(ast_map::NodeItem(i)) => {
1308 ast::ItemFn(_, _, _, _, ref blk) => {
1311 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1314 Some(ast_map::NodeTraitItem(trait_method)) => {
1315 match *trait_method {
1316 ast::ProvidedMethod(ref m) => {
1318 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1321 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1324 ast::RequiredMethod(_) => {
1325 tcx.sess.bug("unexpected variant: required trait method \
1326 in has_nested_returns")
1328 ast::TypeTraitItem(_) => {
1329 tcx.sess.bug("unexpected variant: type trait item in \
1330 has_nested_returns")
1334 Some(ast_map::NodeImplItem(ii)) => {
1336 ast::MethodImplItem(ref m) => {
1338 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1341 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1344 ast::TypeImplItem(_) => {
1345 tcx.sess.bug("unexpected variant: type impl item in \
1346 has_nested_returns")
1350 Some(ast_map::NodeExpr(e)) => {
1352 ast::ExprClosure(_, _, _, ref blk) => {
1355 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1358 Some(ast_map::NodeVariant(..)) |
1359 Some(ast_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1362 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1364 _ => tcx.sess.bug(format!("unexpected variant in has_nested_returns: {}",
1365 tcx.map.path_to_string(id)).as_slice())
1368 (blk.id, Some(cfg::CFG::new(tcx, &**blk)))
1371 // Checks for the presence of "nested returns" in a function.
1372 // Nested returns are when the inner expression of a return expression
1373 // (the 'expr' in 'return expr') contains a return expression. Only cases
1374 // where the outer return is actually reachable are considered. Implicit
1375 // returns from the end of blocks are considered as well.
1377 // This check is needed to handle the case where the inner expression is
1378 // part of a larger expression that may have already partially-filled the
1379 // return slot alloca. This can cause errors related to clean-up due to
1380 // the clobbering of the existing value in the return slot.
1381 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1382 for n in cfg.graph.depth_traverse(cfg.entry) {
1383 match tcx.map.find(n.id) {
1384 Some(ast_map::NodeExpr(ex)) => {
1385 if let ast::ExprRet(Some(ref ret_expr)) = ex.node {
1386 let mut visitor = FindNestedReturn::new();
1387 visit::walk_expr(&mut visitor, &**ret_expr);
1393 Some(ast_map::NodeBlock(blk)) if blk.id == blk_id => {
1394 let mut visitor = FindNestedReturn::new();
1395 visit::walk_expr_opt(&mut visitor, &blk.expr);
1407 // NB: must keep 4 fns in sync:
1410 // - create_datums_for_fn_args.
1414 // Be warned! You must call `init_function` before doing anything with the
1415 // returned function context.
1416 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1420 output_type: ty::FnOutput<'tcx>,
1421 param_substs: &'a Substs<'tcx>,
1423 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1424 -> FunctionContext<'a, 'tcx> {
1425 common::validate_substs(param_substs);
1427 debug!("new_fn_ctxt(path={}, id={}, param_substs={})",
1431 ccx.tcx().map.path_to_string(id).to_string()
1433 id, param_substs.repr(ccx.tcx()));
1435 let uses_outptr = match output_type {
1436 ty::FnConverging(output_type) => {
1437 let substd_output_type =
1438 monomorphize::apply_param_substs(ccx.tcx(), param_substs, &output_type);
1439 type_of::return_uses_outptr(ccx, substd_output_type)
1441 ty::FnDiverging => false
1443 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1444 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1445 let nested_returns = if let Some(ref cfg) = cfg {
1446 has_nested_returns(ccx.tcx(), cfg, blk_id)
1451 let mut fcx = FunctionContext {
1454 llretslotptr: Cell::new(None),
1455 param_env: ty::empty_parameter_environment(ccx.tcx()),
1456 alloca_insert_pt: Cell::new(None),
1457 llreturn: Cell::new(None),
1458 needs_ret_allocas: nested_returns,
1459 personality: Cell::new(None),
1460 caller_expects_out_pointer: uses_outptr,
1461 lllocals: RefCell::new(NodeMap::new()),
1462 llupvars: RefCell::new(NodeMap::new()),
1464 param_substs: param_substs,
1466 block_arena: block_arena,
1468 debug_context: debug_context,
1469 scopes: RefCell::new(Vec::new()),
1474 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1480 /// Performs setup on a newly created function, creating the entry scope block
1481 /// and allocating space for the return pointer.
1482 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1484 output: ty::FnOutput<'tcx>)
1485 -> Block<'a, 'tcx> {
1486 let entry_bcx = fcx.new_temp_block("entry-block");
1488 // Use a dummy instruction as the insertion point for all allocas.
1489 // This is later removed in FunctionContext::cleanup.
1490 fcx.alloca_insert_pt.set(Some(unsafe {
1491 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1492 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1495 if let ty::FnConverging(output_type) = output {
1496 // This shouldn't need to recompute the return type,
1497 // as new_fn_ctxt did it already.
1498 let substd_output_type = fcx.monomorphize(&output_type);
1499 if !return_type_is_void(fcx.ccx, substd_output_type) {
1500 // If the function returns nil/bot, there is no real return
1501 // value, so do not set `llretslotptr`.
1502 if !skip_retptr || fcx.caller_expects_out_pointer {
1503 // Otherwise, we normally allocate the llretslotptr, unless we
1504 // have been instructed to skip it for immediate return
1506 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1514 // NB: must keep 4 fns in sync:
1517 // - create_datums_for_fn_args.
1521 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1523 use trans::datum::{ByRef, ByValue};
1526 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1530 // work around bizarre resolve errors
1531 type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>;
1533 // create_datums_for_fn_args: creates rvalue datums for each of the
1534 // incoming function arguments. These will later be stored into
1535 // appropriate lvalue datums.
1536 pub fn create_datums_for_fn_args<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1537 arg_tys: &[Ty<'tcx>])
1538 -> Vec<RvalueDatum<'tcx>> {
1539 let _icx = push_ctxt("create_datums_for_fn_args");
1541 // Return an array wrapping the ValueRefs that we get from `get_param` for
1542 // each argument into datums.
1543 arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
1544 let llarg = get_param(fcx.llfn, fcx.arg_pos(i) as c_uint);
1545 datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty))
1549 /// Creates rvalue datums for each of the incoming function arguments and
1550 /// tuples the arguments. These will later be stored into appropriate lvalue
1553 /// FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1554 fn create_datums_for_fn_args_under_call_abi<'blk, 'tcx>(
1555 mut bcx: Block<'blk, 'tcx>,
1556 arg_scope: cleanup::CustomScopeIndex,
1557 arg_tys: &[Ty<'tcx>])
1558 -> Vec<RvalueDatum<'tcx>> {
1559 let mut result = Vec::new();
1560 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1561 if i < arg_tys.len() - 1 {
1562 // Regular argument.
1563 let llarg = get_param(bcx.fcx.llfn, bcx.fcx.arg_pos(i) as c_uint);
1564 result.push(datum::Datum::new(llarg, arg_ty, arg_kind(bcx.fcx,
1569 // This is the last argument. Tuple it.
1571 ty::ty_tup(ref tupled_arg_tys) => {
1572 let tuple_args_scope_id = cleanup::CustomScope(arg_scope);
1575 datum::lvalue_scratch_datum(bcx,
1579 tuple_args_scope_id,
1584 for (j, &tupled_arg_ty) in
1585 tupled_arg_tys.iter().enumerate() {
1587 get_param(bcx.fcx.llfn,
1588 bcx.fcx.arg_pos(i + j) as c_uint);
1589 let lldest = GEPi(bcx, llval, &[0, j]);
1590 let datum = datum::Datum::new(
1593 arg_kind(bcx.fcx, tupled_arg_ty));
1594 bcx = datum.store_to(bcx, lldest);
1598 let tuple = unpack_datum!(bcx,
1599 tuple.to_expr_datum()
1600 .to_rvalue_datum(bcx,
1605 bcx.tcx().sess.bug("last argument of a function with \
1606 `rust-call` ABI isn't a tuple?!")
1615 fn copy_args_to_allocas<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1616 arg_scope: cleanup::CustomScopeIndex,
1617 bcx: Block<'blk, 'tcx>,
1619 arg_datums: Vec<RvalueDatum<'tcx>>)
1620 -> Block<'blk, 'tcx> {
1621 debug!("copy_args_to_allocas");
1623 let _icx = push_ctxt("copy_args_to_allocas");
1626 let arg_scope_id = cleanup::CustomScope(arg_scope);
1628 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
1629 // For certain mode/type combinations, the raw llarg values are passed
1630 // by value. However, within the fn body itself, we want to always
1631 // have all locals and arguments be by-ref so that we can cancel the
1632 // cleanup and for better interaction with LLVM's debug info. So, if
1633 // the argument would be passed by value, we store it into an alloca.
1634 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1635 // the event it's not truly needed.
1637 bcx = _match::store_arg(bcx, &*args[i].pat, arg_datum, arg_scope_id);
1639 if fcx.ccx.sess().opts.debuginfo == FullDebugInfo {
1640 debuginfo::create_argument_metadata(bcx, &args[i]);
1647 fn copy_unboxed_closure_args_to_allocas<'blk, 'tcx>(
1648 mut bcx: Block<'blk, 'tcx>,
1649 arg_scope: cleanup::CustomScopeIndex,
1651 arg_datums: Vec<RvalueDatum<'tcx>>,
1652 monomorphized_arg_types: &[Ty<'tcx>])
1653 -> Block<'blk, 'tcx> {
1654 let _icx = push_ctxt("copy_unboxed_closure_args_to_allocas");
1655 let arg_scope_id = cleanup::CustomScope(arg_scope);
1657 assert_eq!(arg_datums.len(), 1);
1659 let arg_datum = arg_datums.into_iter().next().unwrap();
1661 // Untuple the rest of the arguments.
1664 arg_datum.to_lvalue_datum_in_scope(bcx,
1667 let untupled_arg_types = match monomorphized_arg_types[0].sty {
1668 ty::ty_tup(ref types) => types[],
1670 bcx.tcx().sess.span_bug(args[0].pat.span,
1671 "first arg to `rust-call` ABI function \
1675 for j in range(0, args.len()) {
1676 let tuple_element_type = untupled_arg_types[j];
1677 let tuple_element_datum =
1678 tuple_datum.get_element(bcx,
1680 |llval| GEPi(bcx, llval, &[0, j]));
1681 let tuple_element_datum = tuple_element_datum.to_expr_datum();
1682 let tuple_element_datum =
1684 tuple_element_datum.to_rvalue_datum(bcx,
1686 bcx = _match::store_arg(bcx,
1688 tuple_element_datum,
1691 if bcx.fcx.ccx.sess().opts.debuginfo == FullDebugInfo {
1692 debuginfo::create_argument_metadata(bcx, &args[j]);
1699 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1700 // and builds the return block.
1701 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1702 last_bcx: Block<'blk, 'tcx>,
1703 retty: ty::FnOutput<'tcx>) {
1704 let _icx = push_ctxt("finish_fn");
1706 let ret_cx = match fcx.llreturn.get() {
1708 if !last_bcx.terminated.get() {
1709 Br(last_bcx, llreturn);
1711 raw_block(fcx, false, llreturn)
1716 // This shouldn't need to recompute the return type,
1717 // as new_fn_ctxt did it already.
1718 let substd_retty = fcx.monomorphize(&retty);
1719 build_return_block(fcx, ret_cx, substd_retty);
1721 debuginfo::clear_source_location(fcx);
1725 // Builds the return block for a function.
1726 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1727 ret_cx: Block<'blk, 'tcx>,
1728 retty: ty::FnOutput<'tcx>) {
1729 if fcx.llretslotptr.get().is_none() ||
1730 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1731 return RetVoid(ret_cx);
1734 let retslot = if fcx.needs_ret_allocas {
1735 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1737 fcx.llretslotptr.get().unwrap()
1739 let retptr = Value(retslot);
1740 match retptr.get_dominating_store(ret_cx) {
1741 // If there's only a single store to the ret slot, we can directly return
1742 // the value that was stored and omit the store and the alloca
1744 let retval = s.get_operand(0).unwrap().get();
1745 s.erase_from_parent();
1747 if retptr.has_no_uses() {
1748 retptr.erase_from_parent();
1751 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1752 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1757 if fcx.caller_expects_out_pointer {
1758 if let ty::FnConverging(retty) = retty {
1759 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1766 // Otherwise, copy the return value to the ret slot
1767 None => match retty {
1768 ty::FnConverging(retty) => {
1769 if fcx.caller_expects_out_pointer {
1770 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1773 Ret(ret_cx, load_ty(ret_cx, retslot, retty))
1776 ty::FnDiverging => {
1777 if fcx.caller_expects_out_pointer {
1780 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)))
1787 #[derive(Clone, Copy, Eq, PartialEq)]
1788 pub enum IsUnboxedClosureFlag {
1793 // trans_closure: Builds an LLVM function out of a source function.
1794 // If the function closes over its environment a closure will be
1796 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1800 param_substs: &Substs<'tcx>,
1801 fn_ast_id: ast::NodeId,
1802 _attributes: &[ast::Attribute],
1803 output_type: ty::FnOutput<'tcx>,
1805 closure_env: closure::ClosureEnv<'b, 'tcx>) {
1806 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1808 let _icx = push_ctxt("trans_closure");
1809 set_uwtable(llfndecl);
1811 debug!("trans_closure(..., param_substs={})",
1812 param_substs.repr(ccx.tcx()));
1814 let arena = TypedArena::new();
1815 let fcx = new_fn_ctxt(ccx,
1818 closure_env.kind != closure::NotClosure,
1823 let mut bcx = init_function(&fcx, false, output_type);
1825 // cleanup scope for the incoming arguments
1826 let fn_cleanup_debug_loc =
1827 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1828 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1830 let block_ty = node_id_type(bcx, body.id);
1832 // Set up arguments to the function.
1833 let monomorphized_arg_types =
1835 .map(|arg| node_id_type(bcx, arg.id))
1836 .collect::<Vec<_>>();
1837 let monomorphized_arg_types = match closure_env.kind {
1838 closure::NotClosure | closure::BoxedClosure(..) => {
1839 monomorphized_arg_types
1842 // Tuple up closure argument types for the "rust-call" ABI.
1843 closure::UnboxedClosure(..) => {
1844 vec![ty::mk_tup(ccx.tcx(), monomorphized_arg_types)]
1847 for monomorphized_arg_type in monomorphized_arg_types.iter() {
1848 debug!("trans_closure: monomorphized_arg_type: {}",
1849 ty_to_string(ccx.tcx(), *monomorphized_arg_type));
1851 debug!("trans_closure: function lltype: {}",
1852 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1854 let arg_datums = if abi != RustCall {
1855 create_datums_for_fn_args(&fcx,
1856 monomorphized_arg_types[])
1858 create_datums_for_fn_args_under_call_abi(
1861 monomorphized_arg_types[])
1864 bcx = match closure_env.kind {
1865 closure::NotClosure | closure::BoxedClosure(..) => {
1866 copy_args_to_allocas(&fcx,
1872 closure::UnboxedClosure(..) => {
1873 copy_unboxed_closure_args_to_allocas(
1878 monomorphized_arg_types[])
1882 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1884 // Up until here, IR instructions for this function have explicitly not been annotated with
1885 // source code location, so we don't step into call setup code. From here on, source location
1886 // emitting should be enabled.
1887 debuginfo::start_emitting_source_locations(&fcx);
1889 let dest = match fcx.llretslotptr.get() {
1890 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1892 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1897 // This call to trans_block is the place where we bridge between
1898 // translation calls that don't have a return value (trans_crate,
1899 // trans_mod, trans_item, et cetera) and those that do
1900 // (trans_block, trans_expr, et cetera).
1901 bcx = controlflow::trans_block(bcx, body, dest);
1904 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1905 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1910 match fcx.llreturn.get() {
1912 Br(bcx, fcx.return_exit_block());
1913 fcx.pop_custom_cleanup_scope(arg_scope);
1916 // Microoptimization writ large: avoid creating a separate
1917 // llreturn basic block
1918 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1922 // Put return block after all other blocks.
1923 // This somewhat improves single-stepping experience in debugger.
1925 let llreturn = fcx.llreturn.get();
1926 for &llreturn in llreturn.iter() {
1927 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1931 // Insert the mandatory first few basic blocks before lltop.
1932 finish_fn(&fcx, bcx, output_type);
1935 // trans_fn: creates an LLVM function corresponding to a source language
1937 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1941 param_substs: &Substs<'tcx>,
1943 attrs: &[ast::Attribute]) {
1944 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1945 debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx()));
1946 let _icx = push_ctxt("trans_fn");
1947 let fn_ty = ty::node_id_to_type(ccx.tcx(), id);
1948 let output_type = ty::ty_fn_ret(fn_ty);
1949 let abi = ty::ty_fn_abi(fn_ty);
1959 closure::ClosureEnv::new(&[], closure::NotClosure));
1962 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1963 _enum_id: ast::NodeId,
1964 variant: &ast::Variant,
1965 _args: &[ast::VariantArg],
1967 param_substs: &Substs<'tcx>,
1968 llfndecl: ValueRef) {
1969 let _icx = push_ctxt("trans_enum_variant");
1971 trans_enum_variant_or_tuple_like_struct(
1979 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1982 args: callee::CallArgs,
1984 call_info: Option<NodeInfo>)
1985 -> Result<'blk, 'tcx> {
1987 let ccx = bcx.fcx.ccx;
1988 let tcx = ccx.tcx();
1990 let result_ty = match ctor_ty.sty {
1991 ty::ty_bare_fn(_, ref bft) => bft.sig.0.output.unwrap(),
1992 _ => ccx.sess().bug(
1993 format!("trans_enum_variant_constructor: \
1994 unexpected ctor return type {}",
1995 ctor_ty.repr(tcx))[])
1998 // Get location to store the result. If the user does not care about
1999 // the result, just make a stack slot
2000 let llresult = match dest {
2001 expr::SaveIn(d) => d,
2003 if !type_is_zero_size(ccx, result_ty) {
2004 alloc_ty(bcx, result_ty, "constructor_result")
2006 C_undef(type_of::type_of(ccx, result_ty))
2011 if !type_is_zero_size(ccx, result_ty) {
2013 callee::ArgExprs(exprs) => {
2014 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2015 bcx = expr::trans_adt(bcx,
2020 expr::SaveIn(llresult),
2023 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
2027 // If the caller doesn't care about the result
2028 // drop the temporary we made
2029 let bcx = match dest {
2030 expr::SaveIn(_) => bcx,
2032 glue::drop_ty(bcx, llresult, result_ty, call_info)
2036 Result::new(bcx, llresult)
2039 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2040 _fields: &[ast::StructField],
2041 ctor_id: ast::NodeId,
2042 param_substs: &Substs<'tcx>,
2043 llfndecl: ValueRef) {
2044 let _icx = push_ctxt("trans_tuple_struct");
2046 trans_enum_variant_or_tuple_like_struct(
2054 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2055 ctor_id: ast::NodeId,
2057 param_substs: &Substs<'tcx>,
2058 llfndecl: ValueRef) {
2059 let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2060 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2062 let result_ty = match ctor_ty.sty {
2063 ty::ty_bare_fn(_, ref bft) => bft.sig.0.output,
2064 _ => ccx.sess().bug(
2065 format!("trans_enum_variant_or_tuple_like_struct: \
2066 unexpected ctor return type {}",
2067 ty_to_string(ccx.tcx(), ctor_ty))[])
2070 let arena = TypedArena::new();
2071 let fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
2072 param_substs, None, &arena);
2073 let bcx = init_function(&fcx, false, result_ty);
2075 assert!(!fcx.needs_ret_allocas);
2077 let arg_tys = ty::ty_fn_args(ctor_ty);
2079 let arg_datums = create_datums_for_fn_args(&fcx, arg_tys[]);
2081 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2082 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2083 let repr = adt::represent_type(ccx, result_ty.unwrap());
2084 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
2085 let lldestptr = adt::trans_field_ptr(bcx,
2090 arg_datum.store_to(bcx, lldestptr);
2092 adt::trans_set_discr(bcx, &*repr, dest, disr);
2095 finish_fn(&fcx, bcx, result_ty);
2098 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
2099 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2101 let print_info = ccx.sess().print_enum_sizes();
2103 let levels = ccx.tcx().node_lint_levels.borrow();
2104 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2105 let lvlsrc = levels.get(&(id, lint_id));
2106 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2108 if is_allow && !print_info {
2109 // we're not interested in anything here
2113 let ty = ty::node_id_to_type(ccx.tcx(), id);
2114 let avar = adt::represent_type(ccx, ty);
2116 adt::General(_, ref variants, _) => {
2117 for var in variants.iter() {
2119 for field in var.fields.iter().skip(1) {
2120 // skip the discriminant
2121 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2126 _ => { /* its size is either constant or unimportant */ }
2129 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2130 |(l, s, li), (idx, &size)|
2133 } else if size > s {
2141 let llty = type_of::sizing_type_of(ccx, ty);
2143 let sess = &ccx.tcx().sess;
2144 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2146 adt::General(..) => {
2147 for (i, var) in enum_def.variants.iter().enumerate() {
2148 ccx.tcx().sess.span_note(var.span,
2149 &*format!("variant data: {} bytes", sizes[i]));
2156 // we only warn if the largest variant is at least thrice as large as
2157 // the second-largest.
2158 if !is_allow && largest > slargest * 3 && slargest > 0 {
2159 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2160 // pass for the latter already ran.
2161 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
2162 *lvlsrc.unwrap(), Some(sp),
2163 format!("enum variant is more than three times larger \
2164 ({} bytes) than the next largest (ignoring padding)",
2167 ccx.sess().span_note(enum_def.variants[largest_index].span,
2168 "this variant is the largest");
2172 pub struct TransItemVisitor<'a, 'tcx: 'a> {
2173 pub ccx: &'a CrateContext<'a, 'tcx>,
2176 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemVisitor<'a, 'tcx> {
2177 fn visit_item(&mut self, i: &ast::Item) {
2178 trans_item(self.ccx, i);
2182 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2183 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2184 // applicable to variable declarations and may not really make sense for
2185 // Rust code in the first place but whitelist them anyway and trust that
2186 // the user knows what s/he's doing. Who knows, unanticipated use cases
2187 // may pop up in the future.
2189 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2190 // and don't have to be, LLVM treats them as no-ops.
2192 "appending" => Some(llvm::AppendingLinkage),
2193 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2194 "common" => Some(llvm::CommonLinkage),
2195 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2196 "external" => Some(llvm::ExternalLinkage),
2197 "internal" => Some(llvm::InternalLinkage),
2198 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2199 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2200 "private" => Some(llvm::PrivateLinkage),
2201 "weak" => Some(llvm::WeakAnyLinkage),
2202 "weak_odr" => Some(llvm::WeakODRLinkage),
2208 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2210 pub enum ValueOrigin {
2211 /// The LLVM `Value` is in this context because the corresponding item was
2212 /// assigned to the current compilation unit.
2213 OriginalTranslation,
2214 /// The `Value`'s corresponding item was assigned to some other compilation
2215 /// unit, but the `Value` was translated in this context anyway because the
2216 /// item is marked `#[inline]`.
2220 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2221 /// If the `llval` is the direct translation of a specific Rust item, `id`
2222 /// should be set to the `NodeId` of that item. (This mapping should be
2223 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2224 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2225 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2226 /// assigned to a different compilation unit.
2227 pub fn update_linkage(ccx: &CrateContext,
2229 id: Option<ast::NodeId>,
2230 llval_origin: ValueOrigin) {
2231 match llval_origin {
2233 // `llval` is a translation of an item defined in a separate
2234 // compilation unit. This only makes sense if there are at least
2235 // two compilation units.
2236 assert!(ccx.sess().opts.cg.codegen_units > 1);
2237 // `llval` is a copy of something defined elsewhere, so use
2238 // `AvailableExternallyLinkage` to avoid duplicating code in the
2240 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2243 OriginalTranslation => {},
2246 if let Some(id) = id {
2247 let item = ccx.tcx().map.get(id);
2248 if let ast_map::NodeItem(i) = item {
2249 if let Some(name) = attr::first_attr_value_str_by_name(i.attrs[], "linkage") {
2250 if let Some(linkage) = llvm_linkage_by_name(name.get()) {
2251 llvm::SetLinkage(llval, linkage);
2253 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2261 Some(id) if ccx.reachable().contains(&id) => {
2262 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2265 // `id` does not refer to an item in `ccx.reachable`.
2266 if ccx.sess().opts.cg.codegen_units > 1 {
2267 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2269 llvm::SetLinkage(llval, llvm::InternalLinkage);
2275 pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
2276 let _icx = push_ctxt("trans_item");
2278 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2281 ast::ItemFn(ref decl, _fn_style, abi, ref generics, ref body) => {
2282 if !generics.is_type_parameterized() {
2283 let trans_everywhere = attr::requests_inline(item.attrs[]);
2284 // Ignore `trans_everywhere` for cross-crate inlined items
2285 // (`from_external`). `trans_item` will be called once for each
2286 // compilation unit that references the item, so it will still get
2287 // translated everywhere it's needed.
2288 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2289 let llfn = get_item_val(ccx, item.id);
2291 foreign::trans_rust_fn_with_foreign_abi(ccx,
2296 &Substs::trans_empty(),
2304 &Substs::trans_empty(),
2311 if is_origin { OriginalTranslation } else { InlinedCopy });
2315 // Be sure to travel more than just one layer deep to catch nested
2316 // items in blocks and such.
2317 let mut v = TransItemVisitor{ ccx: ccx };
2318 v.visit_block(&**body);
2320 ast::ItemImpl(_, ref generics, _, _, ref impl_items) => {
2321 meth::trans_impl(ccx,
2327 ast::ItemMod(ref m) => {
2328 trans_mod(&ccx.rotate(), m);
2330 ast::ItemEnum(ref enum_definition, ref gens) => {
2331 if gens.ty_params.is_empty() {
2332 // sizes only make sense for non-generic types
2334 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2337 ast::ItemConst(_, ref expr) => {
2338 // Recurse on the expression to catch items in blocks
2339 let mut v = TransItemVisitor{ ccx: ccx };
2340 v.visit_expr(&**expr);
2342 ast::ItemStatic(_, m, ref expr) => {
2343 // Recurse on the expression to catch items in blocks
2344 let mut v = TransItemVisitor{ ccx: ccx };
2345 v.visit_expr(&**expr);
2347 consts::trans_static(ccx, m, item.id);
2348 let g = get_item_val(ccx, item.id);
2349 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2351 // Do static_assert checking. It can't really be done much earlier
2352 // because we need to get the value of the bool out of LLVM
2353 if attr::contains_name(item.attrs[], "static_assert") {
2354 if m == ast::MutMutable {
2355 ccx.sess().span_fatal(expr.span,
2356 "cannot have static_assert on a mutable \
2360 let v = ccx.static_values().borrow()[item.id].clone();
2362 if !(llvm::LLVMConstIntGetZExtValue(v) != 0) {
2363 ccx.sess().span_fatal(expr.span, "static assertion failed");
2368 ast::ItemForeignMod(ref foreign_mod) => {
2369 foreign::trans_foreign_mod(ccx, foreign_mod);
2371 ast::ItemTrait(..) => {
2372 // Inside of this trait definition, we won't be actually translating any
2373 // functions, but the trait still needs to be walked. Otherwise default
2374 // methods with items will not get translated and will cause ICE's when
2375 // metadata time comes around.
2376 let mut v = TransItemVisitor{ ccx: ccx };
2377 visit::walk_item(&mut v, item);
2379 _ => {/* fall through */ }
2383 // Translate a module. Doing this amounts to translating the items in the
2384 // module; there ends up being no artifact (aside from linkage names) of
2385 // separate modules in the compiled program. That's because modules exist
2386 // only as a convenience for humans working with the code, to organize names
2387 // and control visibility.
2388 pub fn trans_mod(ccx: &CrateContext, m: &ast::Mod) {
2389 let _icx = push_ctxt("trans_mod");
2390 for item in m.items.iter() {
2391 trans_item(ccx, &**item);
2395 fn finish_register_fn(ccx: &CrateContext, sp: Span, sym: String, node_id: ast::NodeId,
2397 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2399 // The stack exhaustion lang item shouldn't have a split stack because
2400 // otherwise it would continue to be exhausted (bad), and both it and the
2401 // eh_personality functions need to be externally linkable.
2402 let def = ast_util::local_def(node_id);
2403 if ccx.tcx().lang_items.stack_exhausted() == Some(def) {
2404 unset_split_stack(llfn);
2405 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2407 if ccx.tcx().lang_items.eh_personality() == Some(def) {
2408 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2412 if is_entry_fn(ccx.sess(), node_id) {
2413 create_entry_wrapper(ccx, sp, llfn);
2417 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2420 node_id: ast::NodeId,
2421 node_type: Ty<'tcx>)
2423 match node_type.sty {
2424 ty::ty_bare_fn(_, ref f) => {
2425 assert!(f.abi == Rust || f.abi == RustCall);
2427 _ => panic!("expected bare rust fn")
2430 let llfn = decl_rust_fn(ccx, node_type, sym[]);
2431 finish_register_fn(ccx, sp, sym, node_id, llfn);
2435 pub fn get_fn_llvm_attributes<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>)
2436 -> llvm::AttrBuilder {
2437 use middle::ty::{BrAnon, ReLateBound};
2439 let (fn_sig, abi, has_env) = match fn_ty.sty {
2440 ty::ty_closure(ref f) => (f.sig.clone(), f.abi, true),
2441 ty::ty_bare_fn(_, ref f) => (f.sig.clone(), f.abi, false),
2442 ty::ty_unboxed_closure(closure_did, _, substs) => {
2443 let typer = common::NormalizingUnboxedClosureTyper::new(ccx.tcx());
2444 let function_type = typer.unboxed_closure_type(closure_did, substs);
2445 (function_type.sig, RustCall, true)
2447 _ => ccx.sess().bug("expected closure or function.")
2451 // Since index 0 is the return value of the llvm func, we start
2452 // at either 1 or 2 depending on whether there's an env slot or not
2453 let mut first_arg_offset = if has_env { 2 } else { 1 };
2454 let mut attrs = llvm::AttrBuilder::new();
2455 let ret_ty = fn_sig.0.output;
2457 // These have an odd calling convention, so we need to manually
2458 // unpack the input ty's
2459 let input_tys = match fn_ty.sty {
2460 ty::ty_unboxed_closure(_, _, _) => {
2461 assert!(abi == RustCall);
2463 match fn_sig.0.inputs[0].sty {
2464 ty::ty_tup(ref inputs) => inputs.clone(),
2465 _ => ccx.sess().bug("expected tuple'd inputs")
2468 ty::ty_bare_fn(..) if abi == RustCall => {
2469 let mut inputs = vec![fn_sig.0.inputs[0]];
2471 match fn_sig.0.inputs[1].sty {
2472 ty::ty_tup(ref t_in) => {
2473 inputs.push_all(t_in[]);
2476 _ => ccx.sess().bug("expected tuple'd inputs")
2479 _ => fn_sig.0.inputs.clone()
2482 if let ty::FnConverging(ret_ty) = ret_ty {
2483 // A function pointer is called without the declaration
2484 // available, so we have to apply any attributes with ABI
2485 // implications directly to the call instruction. Right now,
2486 // the only attribute we need to worry about is `sret`.
2487 if type_of::return_uses_outptr(ccx, ret_ty) {
2488 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, ret_ty));
2490 // The outptr can be noalias and nocapture because it's entirely
2491 // invisible to the program. We also know it's nonnull as well
2492 // as how many bytes we can dereference
2493 attrs.arg(1, llvm::StructRetAttribute)
2494 .arg(1, llvm::NoAliasAttribute)
2495 .arg(1, llvm::NoCaptureAttribute)
2496 .arg(1, llvm::DereferenceableAttribute(llret_sz));
2498 // Add one more since there's an outptr
2499 first_arg_offset += 1;
2501 // The `noalias` attribute on the return value is useful to a
2502 // function ptr caller.
2504 // `~` pointer return values never alias because ownership
2506 ty::ty_uniq(it) if !common::type_is_sized(ccx.tcx(), it) => {}
2508 attrs.ret(llvm::NoAliasAttribute);
2513 // We can also mark the return value as `dereferenceable` in certain cases
2515 // These are not really pointers but pairs, (pointer, len)
2517 ty::ty_rptr(_, ty::mt { ty: it, .. }) if !common::type_is_sized(ccx.tcx(), it) => {}
2518 ty::ty_uniq(inner) | ty::ty_rptr(_, ty::mt { ty: inner, .. }) => {
2519 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2520 attrs.ret(llvm::DereferenceableAttribute(llret_sz));
2525 if let ty::ty_bool = ret_ty.sty {
2526 attrs.ret(llvm::ZExtAttribute);
2531 for (idx, &t) in input_tys.iter().enumerate().map(|(i, v)| (i + first_arg_offset, v)) {
2533 // this needs to be first to prevent fat pointers from falling through
2534 _ if !type_is_immediate(ccx, t) => {
2535 let llarg_sz = llsize_of_real(ccx, type_of::type_of(ccx, t));
2537 // For non-immediate arguments the callee gets its own copy of
2538 // the value on the stack, so there are no aliases. It's also
2539 // program-invisible so can't possibly capture
2540 attrs.arg(idx, llvm::NoAliasAttribute)
2541 .arg(idx, llvm::NoCaptureAttribute)
2542 .arg(idx, llvm::DereferenceableAttribute(llarg_sz));
2546 attrs.arg(idx, llvm::ZExtAttribute);
2549 // `~` pointer parameters never alias because ownership is transferred
2550 ty::ty_uniq(inner) => {
2551 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2553 attrs.arg(idx, llvm::NoAliasAttribute)
2554 .arg(idx, llvm::DereferenceableAttribute(llsz));
2557 // `&mut` pointer parameters never alias other parameters, or mutable global data
2559 // `&T` where `T` contains no `UnsafeCell<U>` is immutable, and can be marked as both
2560 // `readonly` and `noalias`, as LLVM's definition of `noalias` is based solely on
2561 // memory dependencies rather than pointer equality
2562 ty::ty_rptr(b, mt) if mt.mutbl == ast::MutMutable ||
2563 !ty::type_contents(ccx.tcx(), mt.ty).interior_unsafe() => {
2565 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2566 attrs.arg(idx, llvm::NoAliasAttribute)
2567 .arg(idx, llvm::DereferenceableAttribute(llsz));
2569 if mt.mutbl == ast::MutImmutable {
2570 attrs.arg(idx, llvm::ReadOnlyAttribute);
2573 if let ReLateBound(_, BrAnon(_)) = *b {
2574 attrs.arg(idx, llvm::NoCaptureAttribute);
2578 // When a reference in an argument has no named lifetime, it's impossible for that
2579 // reference to escape this function (returned or stored beyond the call by a closure).
2580 ty::ty_rptr(&ReLateBound(_, BrAnon(_)), mt) => {
2581 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2582 attrs.arg(idx, llvm::NoCaptureAttribute)
2583 .arg(idx, llvm::DereferenceableAttribute(llsz));
2586 // & pointer parameters are also never null and we know exactly how
2587 // many bytes we can dereference
2588 ty::ty_rptr(_, mt) => {
2589 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2590 attrs.arg(idx, llvm::DereferenceableAttribute(llsz));
2599 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2600 pub fn register_fn_llvmty(ccx: &CrateContext,
2603 node_id: ast::NodeId,
2605 llfty: Type) -> ValueRef {
2606 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2608 let llfn = decl_fn(ccx, sym[], cc, llfty, ty::FnConverging(ty::mk_nil(ccx.tcx())));
2609 finish_register_fn(ccx, sp, sym, node_id, llfn);
2613 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2614 match *sess.entry_fn.borrow() {
2615 Some((entry_id, _)) => node_id == entry_id,
2620 // Create a _rust_main(args: ~[str]) function which will be called from the
2621 // runtime rust_start function
2622 pub fn create_entry_wrapper(ccx: &CrateContext,
2624 main_llfn: ValueRef) {
2625 let et = ccx.sess().entry_type.get().unwrap();
2627 config::EntryMain => {
2628 create_entry_fn(ccx, main_llfn, true);
2630 config::EntryStart => create_entry_fn(ccx, main_llfn, false),
2631 config::EntryNone => {} // Do nothing.
2634 fn create_entry_fn(ccx: &CrateContext,
2635 rust_main: ValueRef,
2636 use_start_lang_item: bool) {
2637 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2640 let llfn = decl_cdecl_fn(ccx, "main", llfty, ty::mk_nil(ccx.tcx()));
2642 // FIXME: #16581: Marking a symbol in the executable with `dllexport`
2643 // linkage forces MinGW's linker to output a `.reloc` section for ASLR
2644 if ccx.sess().target.target.options.is_like_windows {
2645 unsafe { llvm::LLVMRustSetDLLExportStorageClass(llfn) }
2648 let llbb = "top".with_c_str(|buf| {
2650 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, buf)
2653 let bld = ccx.raw_builder();
2655 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2657 debuginfo::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2659 let (start_fn, args) = if use_start_lang_item {
2660 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2662 Err(s) => { ccx.sess().fatal(s[]); }
2664 let start_fn = if start_def_id.krate == ast::LOCAL_CRATE {
2665 get_item_val(ccx, start_def_id.node)
2667 let start_fn_type = csearch::get_type(ccx.tcx(),
2669 trans_external_path(ccx, start_def_id, start_fn_type)
2673 let opaque_rust_main = "rust_main".with_c_str(|buf| {
2674 llvm::LLVMBuildPointerCast(bld, rust_main, Type::i8p(ccx).to_ref(), buf)
2685 debug!("using user-defined start fn");
2687 get_param(llfn, 0 as c_uint),
2688 get_param(llfn, 1 as c_uint)
2694 let result = llvm::LLVMBuildCall(bld,
2697 args.len() as c_uint,
2700 llvm::LLVMBuildRet(bld, result);
2705 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, id: ast::NodeId,
2706 ty: Ty<'tcx>, attrs: &[ast::Attribute]) -> String {
2707 match ccx.external_srcs().borrow().get(&id) {
2709 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2710 debug!("found item {} in other crate...", sym);
2716 match attr::first_attr_value_str_by_name(attrs, "export_name") {
2717 // Use provided name
2718 Some(name) => name.get().to_string(),
2720 _ => ccx.tcx().map.with_path(id, |path| {
2721 if attr::contains_name(attrs, "no_mangle") {
2723 path.last().unwrap().to_string()
2725 match weak_lang_items::link_name(attrs) {
2726 Some(name) => name.get().to_string(),
2728 // Usual name mangling
2729 mangle_exported_name(ccx, path, ty, id)
2737 fn contains_null(s: &str) -> bool {
2738 s.bytes().any(|b| b == 0)
2741 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2742 debug!("get_item_val(id=`{}`)", id);
2744 match ccx.item_vals().borrow().get(&id).cloned() {
2745 Some(v) => return v,
2749 let item = ccx.tcx().map.get(id);
2750 debug!("get_item_val: id={} item={}", id, item);
2751 let val = match item {
2752 ast_map::NodeItem(i) => {
2753 let ty = ty::node_id_to_type(ccx.tcx(), i.id);
2754 let sym = |&:| exported_name(ccx, id, ty, i.attrs[]);
2756 let v = match i.node {
2757 ast::ItemStatic(_, _, ref expr) => {
2758 // If this static came from an external crate, then
2759 // we need to get the symbol from csearch instead of
2760 // using the current crate's name/version
2761 // information in the hash of the symbol
2763 debug!("making {}", sym);
2765 // We need the translated value here, because for enums the
2766 // LLVM type is not fully determined by the Rust type.
2767 let (v, ty) = consts::const_expr(ccx, &**expr);
2768 ccx.static_values().borrow_mut().insert(id, v);
2770 // boolean SSA values are i1, but they have to be stored in i8 slots,
2771 // otherwise some LLVM optimization passes don't work as expected
2772 let llty = if ty::type_is_bool(ty) {
2773 llvm::LLVMInt8TypeInContext(ccx.llcx())
2777 if contains_null(sym[]) {
2779 format!("Illegal null byte in export_name \
2780 value: `{}`", sym)[]);
2782 let g = sym.with_c_str(|buf| {
2783 llvm::LLVMAddGlobal(ccx.llmod(), llty, buf)
2786 if attr::contains_name(i.attrs[],
2788 llvm::set_thread_local(g, true);
2790 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2795 ast::ItemConst(_, ref expr) => {
2796 let (v, _) = consts::const_expr(ccx, &**expr);
2797 ccx.const_values().borrow_mut().insert(id, v);
2801 ast::ItemFn(_, _, abi, _, _) => {
2803 let llfn = if abi == Rust {
2804 register_fn(ccx, i.span, sym, i.id, ty)
2806 foreign::register_rust_fn_with_foreign_abi(ccx,
2811 set_llvm_fn_attrs(ccx, i.attrs[], llfn);
2815 _ => panic!("get_item_val: weird result in table")
2818 match attr::first_attr_value_str_by_name(i.attrs[],
2821 if contains_null(sect.get()) {
2822 ccx.sess().fatal(format!("Illegal null byte in link_section value: `{}`",
2826 sect.get().with_c_str(|buf| {
2827 llvm::LLVMSetSection(v, buf);
2837 ast_map::NodeTraitItem(trait_method) => {
2838 debug!("get_item_val(): processing a NodeTraitItem");
2839 match *trait_method {
2840 ast::RequiredMethod(_) | ast::TypeTraitItem(_) => {
2841 ccx.sess().bug("unexpected variant: required trait \
2842 method in get_item_val()");
2844 ast::ProvidedMethod(ref m) => {
2845 register_method(ccx, id, &**m)
2850 ast_map::NodeImplItem(ii) => {
2852 ast::MethodImplItem(ref m) => register_method(ccx, id, &**m),
2853 ast::TypeImplItem(ref typedef) => {
2854 ccx.sess().span_bug(typedef.span,
2855 "unexpected variant: required impl \
2856 method in get_item_val()")
2861 ast_map::NodeForeignItem(ni) => {
2863 ast::ForeignItemFn(..) => {
2864 let abi = ccx.tcx().map.get_foreign_abi(id);
2865 let ty = ty::node_id_to_type(ccx.tcx(), ni.id);
2866 let name = foreign::link_name(&*ni);
2867 foreign::register_foreign_item_fn(ccx, abi, ty, name.get()[])
2869 ast::ForeignItemStatic(..) => {
2870 foreign::register_static(ccx, &*ni)
2875 ast_map::NodeVariant(ref v) => {
2877 let args = match v.node.kind {
2878 ast::TupleVariantKind(ref args) => args,
2879 ast::StructVariantKind(_) => {
2880 panic!("struct variant kind unexpected in get_item_val")
2883 assert!(args.len() != 0u);
2884 let ty = ty::node_id_to_type(ccx.tcx(), id);
2885 let parent = ccx.tcx().map.get_parent(id);
2886 let enm = ccx.tcx().map.expect_item(parent);
2887 let sym = exported_name(ccx,
2892 llfn = match enm.node {
2893 ast::ItemEnum(_, _) => {
2894 register_fn(ccx, (*v).span, sym, id, ty)
2896 _ => panic!("NodeVariant, shouldn't happen")
2898 set_inline_hint(llfn);
2902 ast_map::NodeStructCtor(struct_def) => {
2903 // Only register the constructor if this is a tuple-like struct.
2904 let ctor_id = match struct_def.ctor_id {
2906 ccx.sess().bug("attempt to register a constructor of \
2907 a non-tuple-like struct")
2909 Some(ctor_id) => ctor_id,
2911 let parent = ccx.tcx().map.get_parent(id);
2912 let struct_item = ccx.tcx().map.expect_item(parent);
2913 let ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2914 let sym = exported_name(ccx,
2919 let llfn = register_fn(ccx, struct_item.span,
2921 set_inline_hint(llfn);
2926 ccx.sess().bug(format!("get_item_val(): unexpected variant: {}",
2931 // All LLVM globals and functions are initially created as external-linkage
2932 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2933 // into a definition, it adjusts the linkage then (using `update_linkage`).
2935 // The exception is foreign items, which have their linkage set inside the
2936 // call to `foreign::register_*` above. We don't touch the linkage after
2937 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2938 // other item translation functions do).
2940 ccx.item_vals().borrow_mut().insert(id, val);
2944 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2945 m: &ast::Method) -> ValueRef {
2946 let mty = ty::node_id_to_type(ccx.tcx(), id);
2948 let sym = exported_name(ccx, id, mty, m.attrs[]);
2950 let llfn = register_fn(ccx, m.span, sym, id, mty);
2951 set_llvm_fn_attrs(ccx, m.attrs[], llfn);
2955 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'tcx>,
2956 ie: encoder::EncodeInlinedItem<'a>)
2957 -> encoder::EncodeParams<'a, 'tcx> {
2958 encoder::EncodeParams {
2959 diag: cx.sess().diagnostic(),
2961 reexports: cx.export_map(),
2962 item_symbols: cx.item_symbols(),
2963 link_meta: cx.link_meta(),
2964 cstore: &cx.sess().cstore,
2965 encode_inlined_item: ie,
2966 reachable: cx.reachable(),
2970 pub fn write_metadata(cx: &SharedCrateContext, krate: &ast::Crate) -> Vec<u8> {
2973 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2974 *ty != config::CrateTypeExecutable
2980 let encode_inlined_item: encoder::EncodeInlinedItem =
2981 |ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii);
2983 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item);
2984 let metadata = encoder::encode_metadata(encode_parms, krate);
2985 let mut compressed = encoder::metadata_encoding_version.to_vec();
2986 compressed.push_all(match flate::deflate_bytes(metadata.as_slice()) {
2987 Some(compressed) => compressed,
2988 None => cx.sess().fatal("failed to compress metadata"),
2990 let llmeta = C_bytes_in_context(cx.metadata_llcx(), compressed[]);
2991 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2992 let name = format!("rust_metadata_{}_{}",
2993 cx.link_meta().crate_name,
2994 cx.link_meta().crate_hash);
2995 let llglobal = name.with_c_str(|buf| {
2997 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf)
3001 llvm::LLVMSetInitializer(llglobal, llconst);
3002 let name = loader::meta_section_name(cx.sess().target.target.options.is_like_osx);
3003 name.with_c_str(|buf| {
3004 llvm::LLVMSetSection(llglobal, buf)
3010 /// Find any symbols that are defined in one compilation unit, but not declared
3011 /// in any other compilation unit. Give these symbols internal linkage.
3012 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<String>) {
3013 use std::c_str::CString;
3016 let mut declared = HashSet::new();
3018 let iter_globals = |&: llmod| {
3020 cur: llvm::LLVMGetFirstGlobal(llmod),
3021 step: llvm::LLVMGetNextGlobal,
3025 let iter_functions = |&: llmod| {
3027 cur: llvm::LLVMGetFirstFunction(llmod),
3028 step: llvm::LLVMGetNextFunction,
3032 // Collect all external declarations in all compilation units.
3033 for ccx in cx.iter() {
3034 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3035 let linkage = llvm::LLVMGetLinkage(val);
3036 // We only care about external declarations (not definitions)
3037 // and available_externally definitions.
3038 if !(linkage == llvm::ExternalLinkage as c_uint &&
3039 llvm::LLVMIsDeclaration(val) != 0) &&
3040 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
3044 let name = CString::new(llvm::LLVMGetValueName(val), false);
3045 declared.insert(name);
3049 // Examine each external definition. If the definition is not used in
3050 // any other compilation unit, and is not reachable from other crates,
3051 // then give it internal linkage.
3052 for ccx in cx.iter() {
3053 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3054 // We only care about external definitions.
3055 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
3056 llvm::LLVMIsDeclaration(val) == 0) {
3060 let name = CString::new(llvm::LLVMGetValueName(val), false);
3061 if !declared.contains(&name) &&
3062 !reachable.contains(name.as_str().unwrap()) {
3063 llvm::SetLinkage(val, llvm::InternalLinkage);
3072 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
3075 impl Iterator for ValueIter {
3076 type Item = ValueRef;
3078 fn next(&mut self) -> Option<ValueRef> {
3082 let step: unsafe extern "C" fn(ValueRef) -> ValueRef =
3083 mem::transmute_copy(&self.step);
3094 pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
3095 -> (ty::ctxt<'tcx>, CrateTranslation) {
3096 let ty::CrateAnalysis { ty_cx: tcx, export_map, reachable, name, .. } = analysis;
3097 let krate = tcx.map.krate();
3099 // Before we touch LLVM, make sure that multithreading is enabled.
3101 use std::sync::{Once, ONCE_INIT};
3102 static INIT: Once = ONCE_INIT;
3103 static mut POISONED: bool = false;
3105 if llvm::LLVMStartMultithreaded() != 1 {
3106 // use an extra bool to make sure that all future usage of LLVM
3107 // cannot proceed despite the Once not running more than once.
3113 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3117 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3119 let codegen_units = tcx.sess.opts.cg.codegen_units;
3120 let shared_ccx = SharedCrateContext::new(link_meta.crate_name[],
3129 let ccx = shared_ccx.get_ccx(0);
3131 // First, verify intrinsics.
3132 intrinsic::check_intrinsics(&ccx);
3134 // Next, translate the module.
3136 let _icx = push_ctxt("text");
3137 trans_mod(&ccx, &krate.module);
3141 for ccx in shared_ccx.iter() {
3142 glue::emit_tydescs(&ccx);
3143 if ccx.sess().opts.debuginfo != NoDebugInfo {
3144 debuginfo::finalize(&ccx);
3148 // Translate the metadata.
3149 let metadata = write_metadata(&shared_ccx, krate);
3151 if shared_ccx.sess().trans_stats() {
3152 let stats = shared_ccx.stats();
3153 println!("--- trans stats ---");
3154 println!("n_static_tydescs: {}", stats.n_static_tydescs.get());
3155 println!("n_glues_created: {}", stats.n_glues_created.get());
3156 println!("n_null_glues: {}", stats.n_null_glues.get());
3157 println!("n_real_glues: {}", stats.n_real_glues.get());
3159 println!("n_fns: {}", stats.n_fns.get());
3160 println!("n_monos: {}", stats.n_monos.get());
3161 println!("n_inlines: {}", stats.n_inlines.get());
3162 println!("n_closures: {}", stats.n_closures.get());
3163 println!("fn stats:");
3164 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3165 insns_b.cmp(&insns_a)
3167 for tuple in stats.fn_stats.borrow().iter() {
3169 (ref name, insns) => {
3170 println!("{} insns, {}", insns, *name);
3175 if shared_ccx.sess().count_llvm_insns() {
3176 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3177 println!("{:7} {}", *v, *k);
3181 let modules = shared_ccx.iter()
3182 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3185 let mut reachable: Vec<String> = shared_ccx.reachable().iter().filter_map(|id| {
3186 shared_ccx.item_symbols().borrow().get(id).map(|s| s.to_string())
3189 // For the purposes of LTO, we add to the reachable set all of the upstream
3190 // reachable extern fns. These functions are all part of the public ABI of
3191 // the final product, so LTO needs to preserve them.
3192 shared_ccx.sess().cstore.iter_crate_data(|cnum, _| {
3193 let syms = csearch::get_reachable_extern_fns(&shared_ccx.sess().cstore, cnum);
3194 reachable.extend(syms.into_iter().map(|did| {
3195 csearch::get_symbol(&shared_ccx.sess().cstore, did)
3199 // Make sure that some other crucial symbols are not eliminated from the
3200 // module. This includes the main function, the crate map (used for debug
3201 // log settings and I/O), and finally the curious rust_stack_exhausted
3202 // symbol. This symbol is required for use by the libmorestack library that
3203 // we link in, so we must ensure that this symbol is not internalized (if
3204 // defined in the crate).
3205 reachable.push("main".to_string());
3206 reachable.push("rust_stack_exhausted".to_string());
3208 // referenced from .eh_frame section on some platforms
3209 reachable.push("rust_eh_personality".to_string());
3210 // referenced from rt/rust_try.ll
3211 reachable.push("rust_eh_personality_catch".to_string());
3213 if codegen_units > 1 {
3214 internalize_symbols(&shared_ccx, &reachable.iter().map(|x| x.clone()).collect());
3217 let metadata_module = ModuleTranslation {
3218 llcx: shared_ccx.metadata_llcx(),
3219 llmod: shared_ccx.metadata_llmod(),
3221 let formats = shared_ccx.tcx().dependency_formats.borrow().clone();
3222 let no_builtins = attr::contains_name(krate.attrs[], "no_builtins");
3224 let translation = CrateTranslation {
3226 metadata_module: metadata_module,
3229 reachable: reachable,
3230 crate_formats: formats,
3231 no_builtins: no_builtins,
3234 (shared_ccx.take_tcx(), translation)