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};
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::ffi::{self, CString};
92 use std::cell::{Cell, RefCell};
93 use std::collections::HashSet;
97 use std::{i8, i16, i32, i64};
98 use syntax::abi::{Rust, RustCall, RustIntrinsic, Abi};
99 use syntax::ast_util::local_def;
100 use syntax::attr::AttrMetaMethods;
102 use syntax::codemap::Span;
103 use syntax::parse::token::InternedString;
104 use syntax::visit::Visitor;
106 use syntax::{ast, ast_util, ast_map};
109 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
114 pub fn with_insn_ctxt<F>(blk: F) where
115 F: FnOnce(&[&'static str]),
117 TASK_LOCAL_INSN_KEY.with(move |slot| {
118 slot.borrow().as_ref().map(move |s| blk(s.as_slice()));
122 pub fn init_insn_ctxt() {
123 TASK_LOCAL_INSN_KEY.with(|slot| {
124 *slot.borrow_mut() = Some(Vec::new());
128 pub struct _InsnCtxt {
129 _cannot_construct_outside_of_this_module: ()
133 impl Drop for _InsnCtxt {
135 TASK_LOCAL_INSN_KEY.with(|slot| {
136 match slot.borrow_mut().as_mut() {
137 Some(ctx) => { ctx.pop(); }
144 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
145 debug!("new InsnCtxt: {}", s);
146 TASK_LOCAL_INSN_KEY.with(|slot| {
147 match slot.borrow_mut().as_mut() {
148 Some(ctx) => ctx.push(s),
152 _InsnCtxt { _cannot_construct_outside_of_this_module: () }
155 pub struct StatRecorder<'a, 'tcx: 'a> {
156 ccx: &'a CrateContext<'a, 'tcx>,
157 name: Option<String>,
161 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
162 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
163 -> StatRecorder<'a, 'tcx> {
164 let istart = ccx.stats().n_llvm_insns.get();
174 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
176 if self.ccx.sess().trans_stats() {
177 let iend = self.ccx.stats().n_llvm_insns.get();
178 self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
179 iend - self.istart));
180 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
181 // Reset LLVM insn count to avoid compound costs.
182 self.ccx.stats().n_llvm_insns.set(self.istart);
187 // only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
188 pub fn decl_fn(ccx: &CrateContext, name: &str, cc: llvm::CallConv,
189 ty: Type, output: ty::FnOutput) -> ValueRef {
191 let buf = CString::from_slice(name.as_bytes());
192 let llfn: ValueRef = unsafe {
193 llvm::LLVMGetOrInsertFunction(ccx.llmod(), buf.as_ptr(), 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 let attrs = csearch::get_item_attrs(&ccx.sess().cstore, did);
252 set_llvm_fn_attrs(ccx, &attrs[], f);
254 ccx.externs().borrow_mut().insert(name.to_string(), f);
258 pub fn self_type_for_unboxed_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
259 closure_id: ast::DefId,
263 let unboxed_closure_kind = ccx.tcx().unboxed_closure_kind(closure_id);
264 match unboxed_closure_kind {
265 ty::FnUnboxedClosureKind => {
266 ty::mk_imm_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
268 ty::FnMutUnboxedClosureKind => {
269 ty::mk_mut_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
271 ty::FnOnceUnboxedClosureKind => fn_ty
275 pub fn kind_for_unboxed_closure(ccx: &CrateContext, closure_id: ast::DefId)
276 -> ty::UnboxedClosureKind {
277 let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
278 (*unboxed_closures)[closure_id].kind
281 pub fn decl_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
282 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
283 debug!("decl_rust_fn(fn_ty={}, name={:?})",
284 fn_ty.repr(ccx.tcx()),
287 let fn_ty = monomorphize::normalize_associated_type(ccx.tcx(), &fn_ty);
289 debug!("decl_rust_fn: fn_ty={} (after normalized associated types)",
290 fn_ty.repr(ccx.tcx()));
292 let function_type; // placeholder so that the memory ownership works out ok
294 let (sig, abi, env) = match fn_ty.sty {
295 ty::ty_bare_fn(_, ref f) => {
296 (&f.sig, f.abi, None)
298 ty::ty_unboxed_closure(closure_did, _, substs) => {
299 let typer = common::NormalizingUnboxedClosureTyper::new(ccx.tcx());
300 function_type = typer.unboxed_closure_type(closure_did, substs);
301 let self_type = self_type_for_unboxed_closure(ccx, closure_did, fn_ty);
302 let llenvironment_type = type_of_explicit_arg(ccx, self_type);
303 debug!("decl_rust_fn: function_type={} self_type={}",
304 function_type.repr(ccx.tcx()),
305 self_type.repr(ccx.tcx()));
306 (&function_type.sig, RustCall, Some(llenvironment_type))
308 _ => panic!("expected closure or fn")
311 let sig = ty::erase_late_bound_regions(ccx.tcx(), sig);
312 let sig = ty::Binder(sig);
314 debug!("decl_rust_fn: sig={} (after erasing regions)",
315 sig.repr(ccx.tcx()));
317 let llfty = type_of_rust_fn(ccx, env, &sig, abi);
319 debug!("decl_rust_fn: llfty={}",
320 ccx.tn().type_to_string(llfty));
322 let llfn = decl_fn(ccx, name, llvm::CCallConv, llfty, sig.0.output /* (1) */);
323 let attrs = get_fn_llvm_attributes(ccx, fn_ty);
324 attrs.apply_llfn(llfn);
326 // (1) it's ok to directly access sig.0.output because we erased all late-bound-regions above
331 pub fn decl_internal_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
332 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
333 let llfn = decl_rust_fn(ccx, fn_ty, name);
334 llvm::SetLinkage(llfn, llvm::InternalLinkage);
338 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: ast::DefId,
339 t: Ty<'tcx>) -> ValueRef {
340 let name = csearch::get_symbol(&ccx.sess().cstore, did);
341 let ty = type_of(ccx, t);
342 match ccx.externs().borrow_mut().get(&name) {
343 Some(n) => return *n,
347 let buf = CString::from_slice(name.as_bytes());
348 let c = llvm::LLVMAddGlobal(ccx.llmod(), ty.to_ref(), buf.as_ptr());
349 // Thread-local statics in some other crate need to *always* be linked
350 // against in a thread-local fashion, so we need to be sure to apply the
351 // thread-local attribute locally if it was present remotely. If we
352 // don't do this then linker errors can be generated where the linker
353 // complains that one object files has a thread local version of the
354 // symbol and another one doesn't.
355 for attr in ty::get_attrs(ccx.tcx(), did).iter() {
356 if attr.check_name("thread_local") {
357 llvm::set_thread_local(c, true);
360 ccx.externs().borrow_mut().insert(name.to_string(), c);
365 // Returns a pointer to the body for the box. The box may be an opaque
366 // box. The result will be casted to the type of body_t, if it is statically
368 pub fn at_box_body<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
369 body_t: Ty<'tcx>, boxptr: ValueRef) -> ValueRef {
370 let _icx = push_ctxt("at_box_body");
372 let ty = Type::at_box(ccx, type_of(ccx, body_t));
373 let boxptr = PointerCast(bcx, boxptr, ty.ptr_to());
374 GEPi(bcx, boxptr, &[0u, abi::BOX_FIELD_BODY])
377 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
378 info_ty: Ty<'tcx>, it: LangItem) -> ast::DefId {
379 match bcx.tcx().lang_items.require(it) {
382 bcx.sess().fatal(&format!("allocation of `{}` {}",
383 bcx.ty_to_string(info_ty),
389 // The following malloc_raw_dyn* functions allocate a box to contain
390 // a given type, but with a potentially dynamic size.
392 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
397 -> Result<'blk, 'tcx> {
398 let _icx = push_ctxt("malloc_raw_exchange");
401 let r = callee::trans_lang_call(bcx,
402 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
406 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
409 // Type descriptor and type glue stuff
411 pub fn get_tydesc<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
412 t: Ty<'tcx>) -> Rc<tydesc_info<'tcx>> {
413 match ccx.tydescs().borrow().get(&t) {
414 Some(inf) => return inf.clone(),
418 ccx.stats().n_static_tydescs.set(ccx.stats().n_static_tydescs.get() + 1u);
419 let inf = Rc::new(glue::declare_tydesc(ccx, t));
421 ccx.tydescs().borrow_mut().insert(t, inf.clone());
425 #[allow(dead_code)] // useful
426 pub fn set_optimize_for_size(f: ValueRef) {
427 llvm::SetFunctionAttribute(f, llvm::OptimizeForSizeAttribute)
430 pub fn set_no_inline(f: ValueRef) {
431 llvm::SetFunctionAttribute(f, llvm::NoInlineAttribute)
434 #[allow(dead_code)] // useful
435 pub fn set_no_unwind(f: ValueRef) {
436 llvm::SetFunctionAttribute(f, llvm::NoUnwindAttribute)
439 // Tell LLVM to emit the information necessary to unwind the stack for the
441 pub fn set_uwtable(f: ValueRef) {
442 llvm::SetFunctionAttribute(f, llvm::UWTableAttribute)
445 pub fn set_inline_hint(f: ValueRef) {
446 llvm::SetFunctionAttribute(f, llvm::InlineHintAttribute)
449 pub fn set_llvm_fn_attrs(ccx: &CrateContext, attrs: &[ast::Attribute], llfn: ValueRef) {
451 // Set the inline hint if there is one
452 match find_inline_attr(attrs) {
453 InlineHint => set_inline_hint(llfn),
454 InlineAlways => set_always_inline(llfn),
455 InlineNever => set_no_inline(llfn),
456 InlineNone => { /* fallthrough */ }
459 for attr in attrs.iter() {
461 match attr.name().get() {
462 "no_stack_check" => unset_split_stack(llfn),
463 "no_split_stack" => {
464 unset_split_stack(llfn);
465 ccx.sess().span_warn(attr.span,
466 "no_split_stack is a deprecated synonym for no_stack_check");
469 llvm::LLVMAddFunctionAttribute(llfn,
470 llvm::FunctionIndex as c_uint,
471 llvm::ColdAttribute as uint64_t)
476 attr::mark_used(attr);
481 pub fn set_always_inline(f: ValueRef) {
482 llvm::SetFunctionAttribute(f, llvm::AlwaysInlineAttribute)
485 pub fn set_split_stack(f: ValueRef) {
487 llvm::LLVMAddFunctionAttrString(f, llvm::FunctionIndex as c_uint,
488 "split-stack\0".as_ptr() as *const _);
492 pub fn unset_split_stack(f: ValueRef) {
494 llvm::LLVMRemoveFunctionAttrString(f, llvm::FunctionIndex as c_uint,
495 "split-stack\0".as_ptr() as *const _);
499 // Double-check that we never ask LLVM to declare the same symbol twice. It
500 // silently mangles such symbols, breaking our linkage model.
501 pub fn note_unique_llvm_symbol(ccx: &CrateContext, sym: String) {
502 if ccx.all_llvm_symbols().borrow().contains(&sym) {
503 ccx.sess().bug(&format!("duplicate LLVM symbol: {}", sym)[]);
505 ccx.all_llvm_symbols().borrow_mut().insert(sym);
509 pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
512 parent_id: ast::DefId,
513 substs: &subst::Substs<'tcx>)
515 let _icx = push_ctxt("trans_res_dtor");
516 let did = inline::maybe_instantiate_inline(ccx, did);
518 if !substs.types.is_empty() {
519 assert_eq!(did.krate, ast::LOCAL_CRATE);
521 // Since we're in trans we don't care for any region parameters
522 let substs = subst::Substs::erased(substs.types.clone());
524 let (val, _, _) = monomorphize::monomorphic_fn(ccx, did, &substs, None);
527 } else if did.krate == ast::LOCAL_CRATE {
528 get_item_val(ccx, did.node)
531 let name = csearch::get_symbol(&ccx.sess().cstore, did);
532 let class_ty = ty::lookup_item_type(tcx, parent_id).ty.subst(tcx, substs);
533 let llty = type_of_dtor(ccx, class_ty);
534 let dtor_ty = ty::mk_ctor_fn(ccx.tcx(),
536 &[glue::get_drop_glue_type(ccx, t)],
537 ty::mk_nil(ccx.tcx()));
539 &mut *ccx.externs().borrow_mut(),
547 // Used only for creating scalar comparison glue.
549 pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
551 pub fn compare_scalar_types<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
556 -> Result<'blk, 'tcx> {
557 let f = |&: a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op));
560 ty::ty_tup(ref tys) if tys.is_empty() => f(nil_type),
561 ty::ty_bool | ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
562 ty::ty_ptr(mt) if common::type_is_sized(cx.tcx(), mt.ty) => f(unsigned_int),
563 ty::ty_int(_) => f(signed_int),
564 ty::ty_float(_) => f(floating_point),
565 // Should never get here, because t is scalar.
566 _ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
571 // A helper function to do the actual comparison of scalar values.
572 pub fn compare_scalar_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
578 let _icx = push_ctxt("compare_scalar_values");
579 fn die(cx: Block) -> ! {
580 cx.sess().bug("compare_scalar_values: must be a comparison operator");
584 // We don't need to do actual comparisons for nil.
585 // () == () holds but () < () does not.
587 ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(cx.ccx(), true),
588 ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(cx.ccx(), false),
589 // refinements would be nice
595 ast::BiEq => llvm::RealOEQ,
596 ast::BiNe => llvm::RealUNE,
597 ast::BiLt => llvm::RealOLT,
598 ast::BiLe => llvm::RealOLE,
599 ast::BiGt => llvm::RealOGT,
600 ast::BiGe => llvm::RealOGE,
603 return FCmp(cx, cmp, lhs, rhs);
607 ast::BiEq => llvm::IntEQ,
608 ast::BiNe => llvm::IntNE,
609 ast::BiLt => llvm::IntSLT,
610 ast::BiLe => llvm::IntSLE,
611 ast::BiGt => llvm::IntSGT,
612 ast::BiGe => llvm::IntSGE,
615 return ICmp(cx, cmp, lhs, rhs);
619 ast::BiEq => llvm::IntEQ,
620 ast::BiNe => llvm::IntNE,
621 ast::BiLt => llvm::IntULT,
622 ast::BiLe => llvm::IntULE,
623 ast::BiGt => llvm::IntUGT,
624 ast::BiGe => llvm::IntUGE,
627 return ICmp(cx, cmp, lhs, rhs);
632 pub fn compare_simd_types<'blk, 'tcx>(
633 cx: Block<'blk, 'tcx>,
642 // The comparison operators for floating point vectors are challenging.
643 // LLVM outputs a `< size x i1 >`, but if we perform a sign extension
644 // then bitcast to a floating point vector, the result will be `-NaN`
645 // for each truth value. Because of this they are unsupported.
646 cx.sess().bug("compare_simd_types: comparison operators \
647 not supported for floating point SIMD types")
649 ty::ty_uint(_) | ty::ty_int(_) => {
651 ast::BiEq => llvm::IntEQ,
652 ast::BiNe => llvm::IntNE,
653 ast::BiLt => llvm::IntSLT,
654 ast::BiLe => llvm::IntSLE,
655 ast::BiGt => llvm::IntSGT,
656 ast::BiGe => llvm::IntSGE,
657 _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
659 let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
660 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
661 // to get the correctly sized type. This will compile to a single instruction
662 // once the IR is converted to assembly if the SIMD instruction is supported
663 // by the target architecture.
664 SExt(cx, ICmp(cx, cmp, lhs, rhs), return_ty)
666 _ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
670 // Iterates through the elements of a structural type.
671 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
675 -> Block<'blk, 'tcx> where
676 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
678 let _icx = push_ctxt("iter_structural_ty");
680 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
681 repr: &adt::Repr<'tcx>,
683 variant: &ty::VariantInfo<'tcx>,
684 substs: &subst::Substs<'tcx>,
686 -> Block<'blk, 'tcx> where
687 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
689 let _icx = push_ctxt("iter_variant");
693 for (i, &arg) in variant.args.iter().enumerate() {
694 let arg = monomorphize::apply_param_substs(tcx, substs, &arg);
695 cx = f(cx, adt::trans_field_ptr(cx, repr, av, variant.disr_val, i), arg);
700 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
703 let data = GEPi(cx, av, &[0, abi::FAT_PTR_ADDR]);
704 let info = GEPi(cx, av, &[0, abi::FAT_PTR_EXTRA]);
705 (Load(cx, data), Some(Load(cx, info)))
710 ty::ty_struct(..) => {
711 let repr = adt::represent_type(cx.ccx(), t);
712 expr::with_field_tys(cx.tcx(), t, None, |discr, field_tys| {
713 for (i, field_ty) in field_tys.iter().enumerate() {
714 let field_ty = field_ty.mt.ty;
715 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
717 let val = if common::type_is_sized(cx.tcx(), field_ty) {
720 let boxed_ty = ty::mk_open(cx.tcx(), field_ty);
721 let scratch = datum::rvalue_scratch_datum(cx, boxed_ty, "__fat_ptr_iter");
722 Store(cx, llfld_a, GEPi(cx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
723 Store(cx, info.unwrap(), GEPi(cx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
726 cx = f(cx, val, field_ty);
730 ty::ty_unboxed_closure(def_id, _, substs) => {
731 let repr = adt::represent_type(cx.ccx(), t);
732 let typer = common::NormalizingUnboxedClosureTyper::new(cx.tcx());
733 let upvars = typer.unboxed_closure_upvars(def_id, substs).unwrap();
734 for (i, upvar) in upvars.iter().enumerate() {
735 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
736 cx = f(cx, llupvar, upvar.ty);
739 ty::ty_vec(_, Some(n)) => {
740 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
741 let unit_ty = ty::sequence_element_type(cx.tcx(), t);
742 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
744 ty::ty_tup(ref args) => {
745 let repr = adt::represent_type(cx.ccx(), t);
746 for (i, arg) in args.iter().enumerate() {
747 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
748 cx = f(cx, llfld_a, *arg);
751 ty::ty_enum(tid, substs) => {
755 let repr = adt::represent_type(ccx, t);
756 let variants = ty::enum_variants(ccx.tcx(), tid);
757 let n_variants = (*variants).len();
759 // NB: we must hit the discriminant first so that structural
760 // comparison know not to proceed when the discriminants differ.
762 match adt::trans_switch(cx, &*repr, av) {
763 (_match::Single, None) => {
764 cx = iter_variant(cx, &*repr, av, &*(*variants)[0],
767 (_match::Switch, Some(lldiscrim_a)) => {
768 cx = f(cx, lldiscrim_a, cx.tcx().types.int);
769 let unr_cx = fcx.new_temp_block("enum-iter-unr");
771 let llswitch = Switch(cx, lldiscrim_a, unr_cx.llbb,
773 let next_cx = fcx.new_temp_block("enum-iter-next");
775 for variant in (*variants).iter() {
778 &format!("enum-iter-variant-{}",
779 &variant.disr_val.to_string()[])
781 match adt::trans_case(cx, &*repr, variant.disr_val) {
782 _match::SingleResult(r) => {
783 AddCase(llswitch, r.val, variant_cx.llbb)
785 _ => ccx.sess().unimpl("value from adt::trans_case \
786 in iter_structural_ty")
789 iter_variant(variant_cx,
795 Br(variant_cx, next_cx.llbb);
799 _ => ccx.sess().unimpl("value from adt::trans_switch \
800 in iter_structural_ty")
804 cx.sess().unimpl(&format!("type in iter_structural_ty: {}",
805 ty_to_string(cx.tcx(), t))[])
811 pub fn cast_shift_expr_rhs(cx: Block,
816 cast_shift_rhs(op, lhs, rhs,
817 |a,b| Trunc(cx, a, b),
818 |a,b| ZExt(cx, a, b))
821 pub fn cast_shift_const_rhs(op: ast::BinOp,
822 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
823 cast_shift_rhs(op, lhs, rhs,
824 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
825 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
828 pub fn cast_shift_rhs<F, G>(op: ast::BinOp,
834 F: FnOnce(ValueRef, Type) -> ValueRef,
835 G: FnOnce(ValueRef, Type) -> ValueRef,
837 // Shifts may have any size int on the rhs
838 if ast_util::is_shift_binop(op) {
839 let mut rhs_llty = val_ty(rhs);
840 let mut lhs_llty = val_ty(lhs);
841 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
842 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
843 let rhs_sz = rhs_llty.int_width();
844 let lhs_sz = lhs_llty.int_width();
847 } else if lhs_sz > rhs_sz {
848 // FIXME (#1877: If shifting by negative
849 // values becomes not undefined then this is wrong.
859 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
860 cx: Block<'blk, 'tcx>,
866 -> Block<'blk, 'tcx> {
867 let (zero_text, overflow_text) = if divrem == ast::BiDiv {
868 ("attempted to divide by zero",
869 "attempted to divide with overflow")
871 ("attempted remainder with a divisor of zero",
872 "attempted remainder with overflow")
874 let (is_zero, is_signed) = match rhs_t.sty {
876 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0u64, false);
877 (ICmp(cx, llvm::IntEQ, rhs, zero), true)
880 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0u64, false);
881 (ICmp(cx, llvm::IntEQ, rhs, zero), false)
884 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}",
885 ty_to_string(cx.tcx(), rhs_t))[]);
888 let bcx = with_cond(cx, is_zero, |bcx| {
889 controlflow::trans_fail(bcx, span, InternedString::new(zero_text))
892 // To quote LLVM's documentation for the sdiv instruction:
894 // Division by zero leads to undefined behavior. Overflow also leads
895 // to undefined behavior; this is a rare case, but can occur, for
896 // example, by doing a 32-bit division of -2147483648 by -1.
898 // In order to avoid undefined behavior, we perform runtime checks for
899 // signed division/remainder which would trigger overflow. For unsigned
900 // integers, no action beyond checking for zero need be taken.
902 let (llty, min) = match rhs_t.sty {
904 let llty = Type::int_from_ty(cx.ccx(), t);
906 ast::TyIs(_) if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
907 ast::TyIs(_) => i64::MIN as u64,
908 ast::TyI8 => i8::MIN as u64,
909 ast::TyI16 => i16::MIN as u64,
910 ast::TyI32 => i32::MIN as u64,
911 ast::TyI64 => i64::MIN as u64,
917 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
918 C_integral(llty, -1, false));
919 with_cond(bcx, minus_one, |bcx| {
920 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
921 C_integral(llty, min, true));
922 with_cond(bcx, is_min, |bcx| {
923 controlflow::trans_fail(bcx, span,
924 InternedString::new(overflow_text))
932 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
933 did: ast::DefId, t: Ty<'tcx>) -> ValueRef {
934 let name = csearch::get_symbol(&ccx.sess().cstore, did);
936 ty::ty_bare_fn(_, ref fn_ty) => {
937 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
939 get_extern_rust_fn(ccx, t, &name[], did)
942 ccx.sess().bug("unexpected intrinsic in trans_external_path")
945 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t,
951 get_extern_const(ccx, did, t)
956 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
960 call_info: Option<NodeInfo>)
961 -> (ValueRef, Block<'blk, 'tcx>) {
962 let _icx = push_ctxt("invoke_");
963 if bcx.unreachable.get() {
964 return (C_null(Type::i8(bcx.ccx())), bcx);
967 let attributes = get_fn_llvm_attributes(bcx.ccx(), fn_ty);
969 match bcx.opt_node_id {
971 debug!("invoke at ???");
974 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
978 if need_invoke(bcx) {
979 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
980 for &llarg in llargs.iter() {
981 debug!("arg: {}", bcx.val_to_string(llarg));
983 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
984 let landing_pad = bcx.fcx.get_landing_pad();
987 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
988 None => debuginfo::clear_source_location(bcx.fcx)
991 let llresult = Invoke(bcx,
997 return (llresult, normal_bcx);
999 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
1000 for &llarg in llargs.iter() {
1001 debug!("arg: {}", bcx.val_to_string(llarg));
1005 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
1006 None => debuginfo::clear_source_location(bcx.fcx)
1009 let llresult = Call(bcx, llfn, &llargs[], Some(attributes));
1010 return (llresult, bcx);
1014 pub fn need_invoke(bcx: Block) -> bool {
1015 if bcx.sess().no_landing_pads() {
1019 // Avoid using invoke if we are already inside a landing pad.
1024 bcx.fcx.needs_invoke()
1027 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1028 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
1029 let _icx = push_ctxt("load_if_immediate");
1030 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
1034 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1035 /// differs from the type used for SSA values. Also handles various special cases where the type
1036 /// gives us better information about what we are loading.
1037 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1038 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
1039 if type_is_zero_size(cx.ccx(), t) {
1040 C_undef(type_of::type_of(cx.ccx(), t))
1041 } else if ty::type_is_bool(t) {
1042 Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
1043 } else if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
1044 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1045 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1046 // and we have to convert it
1047 Load(cx, BitCast(cx, ptr, type_of::arg_type_of(cx.ccx(), t).ptr_to()))
1048 } else if ty::type_is_char(t) {
1049 // a char is a Unicode codepoint, and so takes values from 0
1050 // to 0x10FFFF inclusive only.
1051 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1057 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1058 /// differs from the type used for SSA values.
1059 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1060 if ty::type_is_bool(t) {
1061 Store(cx, ZExt(cx, v, Type::i8(cx.ccx())), dst);
1062 } else if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
1063 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1064 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1065 // and we have to convert it
1066 Store(cx, v, BitCast(cx, dst, type_of::arg_type_of(cx.ccx(), t).ptr_to()));
1072 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &ast::Local)
1073 -> Block<'blk, 'tcx> {
1074 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1075 let _indenter = indenter();
1076 let _icx = push_ctxt("init_local");
1077 _match::store_local(bcx, local)
1080 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1082 llbb: BasicBlockRef)
1083 -> Block<'blk, 'tcx> {
1084 common::BlockS::new(llbb, is_lpad, None, fcx)
1087 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
1090 -> Block<'blk, 'tcx> where
1091 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
1093 let _icx = push_ctxt("with_cond");
1095 let next_cx = fcx.new_temp_block("next");
1096 let cond_cx = fcx.new_temp_block("cond");
1097 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb);
1098 let after_cx = f(cond_cx);
1099 if !after_cx.terminated.get() {
1100 Br(after_cx, next_cx.llbb);
1105 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1106 if cx.sess().opts.optimize == config::No {
1110 let _icx = push_ctxt("lifetime_start");
1113 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1114 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1115 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1116 Call(cx, lifetime_start, &[llsize, ptr], None);
1119 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1120 if cx.sess().opts.optimize == config::No {
1124 let _icx = push_ctxt("lifetime_end");
1127 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1128 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1129 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1130 Call(cx, lifetime_end, &[llsize, ptr], None);
1133 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1134 let _icx = push_ctxt("call_memcpy");
1136 let key = match &ccx.sess().target.target.target_pointer_width[] {
1137 "32" => "llvm.memcpy.p0i8.p0i8.i32",
1138 "64" => "llvm.memcpy.p0i8.p0i8.i64",
1139 tws => panic!("Unsupported target word size for memcpy: {}", tws),
1141 let memcpy = ccx.get_intrinsic(&key);
1142 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1143 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1144 let size = IntCast(cx, n_bytes, ccx.int_type());
1145 let align = C_i32(ccx, align as i32);
1146 let volatile = C_bool(ccx, false);
1147 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None);
1150 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1151 dst: ValueRef, src: ValueRef,
1153 let _icx = push_ctxt("memcpy_ty");
1154 let ccx = bcx.ccx();
1155 if ty::type_is_structural(t) {
1156 let llty = type_of::type_of(ccx, t);
1157 let llsz = llsize_of(ccx, llty);
1158 let llalign = type_of::align_of(ccx, t);
1159 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1161 store_ty(bcx, Load(bcx, src), dst, t);
1165 pub fn zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1166 if cx.unreachable.get() { return; }
1167 let _icx = push_ctxt("zero_mem");
1169 memzero(&B(bcx), llptr, t);
1172 // Always use this function instead of storing a zero constant to the memory
1173 // in question. If you store a zero constant, LLVM will drown in vreg
1174 // allocation for large data structures, and the generated code will be
1175 // awful. (A telltale sign of this is large quantities of
1176 // `mov [byte ptr foo],0` in the generated code.)
1177 fn memzero<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>) {
1178 let _icx = push_ctxt("memzero");
1181 let llty = type_of::type_of(ccx, ty);
1183 let intrinsic_key = match &ccx.sess().target.target.target_pointer_width[] {
1184 "32" => "llvm.memset.p0i8.i32",
1185 "64" => "llvm.memset.p0i8.i64",
1186 tws => panic!("Unsupported target word size for memset: {}", tws),
1189 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1190 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1191 let llzeroval = C_u8(ccx, 0);
1192 let size = machine::llsize_of(ccx, llty);
1193 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1194 let volatile = C_bool(ccx, false);
1195 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1198 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1199 let _icx = push_ctxt("alloc_ty");
1200 let ccx = bcx.ccx();
1201 let ty = type_of::type_of(ccx, t);
1202 assert!(!ty::type_has_params(t));
1203 let val = alloca(bcx, ty, name);
1207 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1208 let p = alloca_no_lifetime(cx, ty, name);
1209 call_lifetime_start(cx, p);
1213 pub fn alloca_no_lifetime(cx: Block, ty: Type, name: &str) -> ValueRef {
1214 let _icx = push_ctxt("alloca");
1215 if cx.unreachable.get() {
1217 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1220 debuginfo::clear_source_location(cx.fcx);
1221 Alloca(cx, ty, name)
1224 pub fn alloca_zeroed<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>,
1225 name: &str) -> ValueRef {
1226 let llty = type_of::type_of(cx.ccx(), ty);
1227 if cx.unreachable.get() {
1229 return llvm::LLVMGetUndef(llty.ptr_to().to_ref());
1232 let p = alloca_no_lifetime(cx, llty, name);
1233 let b = cx.fcx.ccx.builder();
1234 b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
1239 pub fn arrayalloca(cx: Block, ty: Type, v: ValueRef) -> ValueRef {
1240 let _icx = push_ctxt("arrayalloca");
1241 if cx.unreachable.get() {
1243 return llvm::LLVMGetUndef(ty.to_ref());
1246 debuginfo::clear_source_location(cx.fcx);
1247 let p = ArrayAlloca(cx, ty, v);
1248 call_lifetime_start(cx, p);
1252 // Creates the alloca slot which holds the pointer to the slot for the final return value
1253 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1254 output_type: Ty<'tcx>) -> ValueRef {
1255 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1257 // We create an alloca to hold a pointer of type `output_type`
1258 // which will hold the pointer to the right alloca which has the
1260 if fcx.needs_ret_allocas {
1261 // Let's create the stack slot
1262 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1264 // and if we're using an out pointer, then store that in our newly made slot
1265 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1266 let outptr = get_param(fcx.llfn, 0);
1268 let b = fcx.ccx.builder();
1269 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1270 b.store(outptr, slot);
1275 // But if there are no nested returns, we skip the indirection and have a single
1278 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1279 get_param(fcx.llfn, 0)
1281 AllocaFcx(fcx, lloutputtype, "sret_slot")
1286 struct FindNestedReturn {
1290 impl FindNestedReturn {
1291 fn new() -> FindNestedReturn {
1292 FindNestedReturn { found: false }
1296 impl<'v> Visitor<'v> for FindNestedReturn {
1297 fn visit_expr(&mut self, e: &ast::Expr) {
1299 ast::ExprRet(..) => {
1302 _ => visit::walk_expr(self, e)
1307 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1308 let blk = match tcx.map.find(id) {
1309 Some(ast_map::NodeItem(i)) => {
1311 ast::ItemFn(_, _, _, _, ref blk) => {
1314 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1317 Some(ast_map::NodeTraitItem(trait_method)) => {
1318 match *trait_method {
1319 ast::ProvidedMethod(ref m) => {
1321 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1324 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1327 ast::RequiredMethod(_) => {
1328 tcx.sess.bug("unexpected variant: required trait method \
1329 in has_nested_returns")
1331 ast::TypeTraitItem(_) => {
1332 tcx.sess.bug("unexpected variant: type trait item in \
1333 has_nested_returns")
1337 Some(ast_map::NodeImplItem(ii)) => {
1339 ast::MethodImplItem(ref m) => {
1341 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1344 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1347 ast::TypeImplItem(_) => {
1348 tcx.sess.bug("unexpected variant: type impl item in \
1349 has_nested_returns")
1353 Some(ast_map::NodeExpr(e)) => {
1355 ast::ExprClosure(_, _, _, ref blk) => {
1358 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1361 Some(ast_map::NodeVariant(..)) |
1362 Some(ast_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1365 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1367 _ => tcx.sess.bug(format!("unexpected variant in has_nested_returns: {}",
1368 tcx.map.path_to_string(id)).as_slice())
1371 (blk.id, Some(cfg::CFG::new(tcx, &**blk)))
1374 // Checks for the presence of "nested returns" in a function.
1375 // Nested returns are when the inner expression of a return expression
1376 // (the 'expr' in 'return expr') contains a return expression. Only cases
1377 // where the outer return is actually reachable are considered. Implicit
1378 // returns from the end of blocks are considered as well.
1380 // This check is needed to handle the case where the inner expression is
1381 // part of a larger expression that may have already partially-filled the
1382 // return slot alloca. This can cause errors related to clean-up due to
1383 // the clobbering of the existing value in the return slot.
1384 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1385 for n in cfg.graph.depth_traverse(cfg.entry) {
1386 match tcx.map.find(n.id) {
1387 Some(ast_map::NodeExpr(ex)) => {
1388 if let ast::ExprRet(Some(ref ret_expr)) = ex.node {
1389 let mut visitor = FindNestedReturn::new();
1390 visit::walk_expr(&mut visitor, &**ret_expr);
1396 Some(ast_map::NodeBlock(blk)) if blk.id == blk_id => {
1397 let mut visitor = FindNestedReturn::new();
1398 visit::walk_expr_opt(&mut visitor, &blk.expr);
1410 // NB: must keep 4 fns in sync:
1413 // - create_datums_for_fn_args.
1417 // Be warned! You must call `init_function` before doing anything with the
1418 // returned function context.
1419 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1423 output_type: ty::FnOutput<'tcx>,
1424 param_substs: &'a Substs<'tcx>,
1426 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1427 -> FunctionContext<'a, 'tcx> {
1428 common::validate_substs(param_substs);
1430 debug!("new_fn_ctxt(path={}, id={}, param_substs={})",
1434 ccx.tcx().map.path_to_string(id).to_string()
1436 id, param_substs.repr(ccx.tcx()));
1438 let uses_outptr = match output_type {
1439 ty::FnConverging(output_type) => {
1440 let substd_output_type =
1441 monomorphize::apply_param_substs(ccx.tcx(), param_substs, &output_type);
1442 type_of::return_uses_outptr(ccx, substd_output_type)
1444 ty::FnDiverging => false
1446 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1447 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1448 let nested_returns = if let Some(ref cfg) = cfg {
1449 has_nested_returns(ccx.tcx(), cfg, blk_id)
1454 let mut fcx = FunctionContext {
1457 llretslotptr: Cell::new(None),
1458 param_env: ty::empty_parameter_environment(ccx.tcx()),
1459 alloca_insert_pt: Cell::new(None),
1460 llreturn: Cell::new(None),
1461 needs_ret_allocas: nested_returns,
1462 personality: Cell::new(None),
1463 caller_expects_out_pointer: uses_outptr,
1464 lllocals: RefCell::new(NodeMap::new()),
1465 llupvars: RefCell::new(NodeMap::new()),
1467 param_substs: param_substs,
1469 block_arena: block_arena,
1471 debug_context: debug_context,
1472 scopes: RefCell::new(Vec::new()),
1477 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1483 /// Performs setup on a newly created function, creating the entry scope block
1484 /// and allocating space for the return pointer.
1485 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1487 output: ty::FnOutput<'tcx>)
1488 -> Block<'a, 'tcx> {
1489 let entry_bcx = fcx.new_temp_block("entry-block");
1491 // Use a dummy instruction as the insertion point for all allocas.
1492 // This is later removed in FunctionContext::cleanup.
1493 fcx.alloca_insert_pt.set(Some(unsafe {
1494 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1495 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1498 if let ty::FnConverging(output_type) = output {
1499 // This shouldn't need to recompute the return type,
1500 // as new_fn_ctxt did it already.
1501 let substd_output_type = fcx.monomorphize(&output_type);
1502 if !return_type_is_void(fcx.ccx, substd_output_type) {
1503 // If the function returns nil/bot, there is no real return
1504 // value, so do not set `llretslotptr`.
1505 if !skip_retptr || fcx.caller_expects_out_pointer {
1506 // Otherwise, we normally allocate the llretslotptr, unless we
1507 // have been instructed to skip it for immediate return
1509 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1517 // NB: must keep 4 fns in sync:
1520 // - create_datums_for_fn_args.
1524 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1526 use trans::datum::{ByRef, ByValue};
1529 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1533 // work around bizarre resolve errors
1534 type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>;
1536 // create_datums_for_fn_args: creates rvalue datums for each of the
1537 // incoming function arguments. These will later be stored into
1538 // appropriate lvalue datums.
1539 pub fn create_datums_for_fn_args<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1540 arg_tys: &[Ty<'tcx>])
1541 -> Vec<RvalueDatum<'tcx>> {
1542 let _icx = push_ctxt("create_datums_for_fn_args");
1544 // Return an array wrapping the ValueRefs that we get from `get_param` for
1545 // each argument into datums.
1546 arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
1547 let llarg = get_param(fcx.llfn, fcx.arg_pos(i) as c_uint);
1548 datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty))
1552 /// Creates rvalue datums for each of the incoming function arguments and
1553 /// tuples the arguments. These will later be stored into appropriate lvalue
1556 /// FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1557 fn create_datums_for_fn_args_under_call_abi<'blk, 'tcx>(
1558 mut bcx: Block<'blk, 'tcx>,
1559 arg_scope: cleanup::CustomScopeIndex,
1560 arg_tys: &[Ty<'tcx>])
1561 -> Vec<RvalueDatum<'tcx>> {
1562 let mut result = Vec::new();
1563 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1564 if i < arg_tys.len() - 1 {
1565 // Regular argument.
1566 let llarg = get_param(bcx.fcx.llfn, bcx.fcx.arg_pos(i) as c_uint);
1567 result.push(datum::Datum::new(llarg, arg_ty, arg_kind(bcx.fcx,
1572 // This is the last argument. Tuple it.
1574 ty::ty_tup(ref tupled_arg_tys) => {
1575 let tuple_args_scope_id = cleanup::CustomScope(arg_scope);
1578 datum::lvalue_scratch_datum(bcx,
1582 tuple_args_scope_id,
1587 for (j, &tupled_arg_ty) in
1588 tupled_arg_tys.iter().enumerate() {
1590 get_param(bcx.fcx.llfn,
1591 bcx.fcx.arg_pos(i + j) as c_uint);
1592 let lldest = GEPi(bcx, llval, &[0, j]);
1593 let datum = datum::Datum::new(
1596 arg_kind(bcx.fcx, tupled_arg_ty));
1597 bcx = datum.store_to(bcx, lldest);
1601 let tuple = unpack_datum!(bcx,
1602 tuple.to_expr_datum()
1603 .to_rvalue_datum(bcx,
1608 bcx.tcx().sess.bug("last argument of a function with \
1609 `rust-call` ABI isn't a tuple?!")
1618 fn copy_args_to_allocas<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1619 arg_scope: cleanup::CustomScopeIndex,
1621 arg_datums: Vec<RvalueDatum<'tcx>>)
1622 -> Block<'blk, 'tcx> {
1623 debug!("copy_args_to_allocas");
1625 let _icx = push_ctxt("copy_args_to_allocas");
1628 let arg_scope_id = cleanup::CustomScope(arg_scope);
1630 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
1631 // For certain mode/type combinations, the raw llarg values are passed
1632 // by value. However, within the fn body itself, we want to always
1633 // have all locals and arguments be by-ref so that we can cancel the
1634 // cleanup and for better interaction with LLVM's debug info. So, if
1635 // the argument would be passed by value, we store it into an alloca.
1636 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1637 // the event it's not truly needed.
1639 bcx = _match::store_arg(bcx, &*args[i].pat, arg_datum, arg_scope_id);
1640 debuginfo::create_argument_metadata(bcx, &args[i]);
1646 fn copy_unboxed_closure_args_to_allocas<'blk, 'tcx>(
1647 mut bcx: Block<'blk, 'tcx>,
1648 arg_scope: cleanup::CustomScopeIndex,
1650 arg_datums: Vec<RvalueDatum<'tcx>>,
1651 monomorphized_arg_types: &[Ty<'tcx>])
1652 -> Block<'blk, 'tcx> {
1653 let _icx = push_ctxt("copy_unboxed_closure_args_to_allocas");
1654 let arg_scope_id = cleanup::CustomScope(arg_scope);
1656 assert_eq!(arg_datums.len(), 1);
1658 let arg_datum = arg_datums.into_iter().next().unwrap();
1660 // Untuple the rest of the arguments.
1663 arg_datum.to_lvalue_datum_in_scope(bcx,
1666 let untupled_arg_types = match monomorphized_arg_types[0].sty {
1667 ty::ty_tup(ref types) => &types[],
1669 bcx.tcx().sess.span_bug(args[0].pat.span,
1670 "first arg to `rust-call` ABI function \
1674 for j in range(0, args.len()) {
1675 let tuple_element_type = untupled_arg_types[j];
1676 let tuple_element_datum =
1677 tuple_datum.get_element(bcx,
1679 |llval| GEPi(bcx, llval, &[0, j]));
1680 let tuple_element_datum = tuple_element_datum.to_expr_datum();
1681 let tuple_element_datum =
1683 tuple_element_datum.to_rvalue_datum(bcx,
1685 bcx = _match::store_arg(bcx,
1687 tuple_element_datum,
1690 debuginfo::create_argument_metadata(bcx, &args[j]);
1696 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1697 // and builds the return block.
1698 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1699 last_bcx: Block<'blk, 'tcx>,
1700 retty: ty::FnOutput<'tcx>) {
1701 let _icx = push_ctxt("finish_fn");
1703 let ret_cx = match fcx.llreturn.get() {
1705 if !last_bcx.terminated.get() {
1706 Br(last_bcx, llreturn);
1708 raw_block(fcx, false, llreturn)
1713 // This shouldn't need to recompute the return type,
1714 // as new_fn_ctxt did it already.
1715 let substd_retty = fcx.monomorphize(&retty);
1716 build_return_block(fcx, ret_cx, substd_retty);
1718 debuginfo::clear_source_location(fcx);
1722 // Builds the return block for a function.
1723 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1724 ret_cx: Block<'blk, 'tcx>,
1725 retty: ty::FnOutput<'tcx>) {
1726 if fcx.llretslotptr.get().is_none() ||
1727 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1728 return RetVoid(ret_cx);
1731 let retslot = if fcx.needs_ret_allocas {
1732 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1734 fcx.llretslotptr.get().unwrap()
1736 let retptr = Value(retslot);
1737 match retptr.get_dominating_store(ret_cx) {
1738 // If there's only a single store to the ret slot, we can directly return
1739 // the value that was stored and omit the store and the alloca
1741 let retval = s.get_operand(0).unwrap().get();
1742 s.erase_from_parent();
1744 if retptr.has_no_uses() {
1745 retptr.erase_from_parent();
1748 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1749 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1754 if fcx.caller_expects_out_pointer {
1755 if let ty::FnConverging(retty) = retty {
1756 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1763 // Otherwise, copy the return value to the ret slot
1764 None => match retty {
1765 ty::FnConverging(retty) => {
1766 if fcx.caller_expects_out_pointer {
1767 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1770 Ret(ret_cx, load_ty(ret_cx, retslot, retty))
1773 ty::FnDiverging => {
1774 if fcx.caller_expects_out_pointer {
1777 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)))
1784 #[derive(Clone, Copy, Eq, PartialEq)]
1785 pub enum IsUnboxedClosureFlag {
1790 // trans_closure: Builds an LLVM function out of a source function.
1791 // If the function closes over its environment a closure will be
1793 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1797 param_substs: &Substs<'tcx>,
1798 fn_ast_id: ast::NodeId,
1799 _attributes: &[ast::Attribute],
1800 output_type: ty::FnOutput<'tcx>,
1802 closure_env: closure::ClosureEnv<'b, 'tcx>) {
1803 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1805 let _icx = push_ctxt("trans_closure");
1806 set_uwtable(llfndecl);
1808 debug!("trans_closure(..., param_substs={})",
1809 param_substs.repr(ccx.tcx()));
1811 let arena = TypedArena::new();
1812 let fcx = new_fn_ctxt(ccx,
1815 closure_env.kind != closure::NotClosure,
1820 let mut bcx = init_function(&fcx, false, output_type);
1822 // cleanup scope for the incoming arguments
1823 let fn_cleanup_debug_loc =
1824 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1825 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1827 let block_ty = node_id_type(bcx, body.id);
1829 // Set up arguments to the function.
1830 let monomorphized_arg_types =
1832 .map(|arg| node_id_type(bcx, arg.id))
1833 .collect::<Vec<_>>();
1834 let monomorphized_arg_types = match closure_env.kind {
1835 closure::NotClosure | closure::BoxedClosure(..) => {
1836 monomorphized_arg_types
1839 // Tuple up closure argument types for the "rust-call" ABI.
1840 closure::UnboxedClosure(..) => {
1841 vec![ty::mk_tup(ccx.tcx(), monomorphized_arg_types)]
1844 for monomorphized_arg_type in monomorphized_arg_types.iter() {
1845 debug!("trans_closure: monomorphized_arg_type: {}",
1846 ty_to_string(ccx.tcx(), *monomorphized_arg_type));
1848 debug!("trans_closure: function lltype: {}",
1849 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1851 let arg_datums = if abi != RustCall {
1852 create_datums_for_fn_args(&fcx,
1853 &monomorphized_arg_types[])
1855 create_datums_for_fn_args_under_call_abi(
1858 &monomorphized_arg_types[])
1861 bcx = match closure_env.kind {
1862 closure::NotClosure | closure::BoxedClosure(..) => {
1863 copy_args_to_allocas(bcx,
1868 closure::UnboxedClosure(..) => {
1869 copy_unboxed_closure_args_to_allocas(
1874 &monomorphized_arg_types[])
1878 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1880 // Up until here, IR instructions for this function have explicitly not been annotated with
1881 // source code location, so we don't step into call setup code. From here on, source location
1882 // emitting should be enabled.
1883 debuginfo::start_emitting_source_locations(&fcx);
1885 let dest = match fcx.llretslotptr.get() {
1886 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1888 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1893 // This call to trans_block is the place where we bridge between
1894 // translation calls that don't have a return value (trans_crate,
1895 // trans_mod, trans_item, et cetera) and those that do
1896 // (trans_block, trans_expr, et cetera).
1897 bcx = controlflow::trans_block(bcx, body, dest);
1900 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1901 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1906 match fcx.llreturn.get() {
1908 Br(bcx, fcx.return_exit_block());
1909 fcx.pop_custom_cleanup_scope(arg_scope);
1912 // Microoptimization writ large: avoid creating a separate
1913 // llreturn basic block
1914 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1918 // Put return block after all other blocks.
1919 // This somewhat improves single-stepping experience in debugger.
1921 let llreturn = fcx.llreturn.get();
1922 for &llreturn in llreturn.iter() {
1923 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1927 // Insert the mandatory first few basic blocks before lltop.
1928 finish_fn(&fcx, bcx, output_type);
1931 // trans_fn: creates an LLVM function corresponding to a source language
1933 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1937 param_substs: &Substs<'tcx>,
1939 attrs: &[ast::Attribute]) {
1940 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1941 debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx()));
1942 let _icx = push_ctxt("trans_fn");
1943 let fn_ty = ty::node_id_to_type(ccx.tcx(), id);
1944 let output_type = ty::erase_late_bound_regions(ccx.tcx(), &ty::ty_fn_ret(fn_ty));
1945 let abi = ty::ty_fn_abi(fn_ty);
1955 closure::ClosureEnv::new(&[], closure::NotClosure));
1958 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1959 _enum_id: ast::NodeId,
1960 variant: &ast::Variant,
1961 _args: &[ast::VariantArg],
1963 param_substs: &Substs<'tcx>,
1964 llfndecl: ValueRef) {
1965 let _icx = push_ctxt("trans_enum_variant");
1967 trans_enum_variant_or_tuple_like_struct(
1975 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1978 args: callee::CallArgs,
1980 call_info: Option<NodeInfo>)
1981 -> Result<'blk, 'tcx> {
1983 let ccx = bcx.fcx.ccx;
1984 let tcx = ccx.tcx();
1986 let result_ty = match ctor_ty.sty {
1987 ty::ty_bare_fn(_, ref bft) => {
1988 ty::erase_late_bound_regions(bcx.tcx(), &bft.sig.output()).unwrap()
1990 _ => ccx.sess().bug(
1991 &format!("trans_enum_variant_constructor: \
1992 unexpected ctor return type {}",
1993 ctor_ty.repr(tcx))[])
1996 // Get location to store the result. If the user does not care about
1997 // the result, just make a stack slot
1998 let llresult = match dest {
1999 expr::SaveIn(d) => d,
2001 if !type_is_zero_size(ccx, result_ty) {
2002 alloc_ty(bcx, result_ty, "constructor_result")
2004 C_undef(type_of::type_of(ccx, result_ty))
2009 if !type_is_zero_size(ccx, result_ty) {
2011 callee::ArgExprs(exprs) => {
2012 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2013 bcx = expr::trans_adt(bcx,
2018 expr::SaveIn(llresult),
2021 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
2025 // If the caller doesn't care about the result
2026 // drop the temporary we made
2027 let bcx = match dest {
2028 expr::SaveIn(_) => bcx,
2030 glue::drop_ty(bcx, llresult, result_ty, call_info)
2034 Result::new(bcx, llresult)
2037 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2038 _fields: &[ast::StructField],
2039 ctor_id: ast::NodeId,
2040 param_substs: &Substs<'tcx>,
2041 llfndecl: ValueRef) {
2042 let _icx = push_ctxt("trans_tuple_struct");
2044 trans_enum_variant_or_tuple_like_struct(
2052 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2053 ctor_id: ast::NodeId,
2055 param_substs: &Substs<'tcx>,
2056 llfndecl: ValueRef) {
2057 let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2058 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2060 let result_ty = match ctor_ty.sty {
2061 ty::ty_bare_fn(_, ref bft) => {
2062 ty::erase_late_bound_regions(ccx.tcx(), &bft.sig.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);
2078 ty::erase_late_bound_regions(
2079 ccx.tcx(), &ty::ty_fn_args(ctor_ty));
2081 let arg_datums = create_datums_for_fn_args(&fcx, &arg_tys[]);
2083 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2084 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2085 let repr = adt::represent_type(ccx, result_ty.unwrap());
2086 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
2087 let lldestptr = adt::trans_field_ptr(bcx,
2092 arg_datum.store_to(bcx, lldestptr);
2094 adt::trans_set_discr(bcx, &*repr, dest, disr);
2097 finish_fn(&fcx, bcx, result_ty);
2100 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
2101 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2103 let print_info = ccx.sess().print_enum_sizes();
2105 let levels = ccx.tcx().node_lint_levels.borrow();
2106 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2107 let lvlsrc = levels.get(&(id, lint_id));
2108 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2110 if is_allow && !print_info {
2111 // we're not interested in anything here
2115 let ty = ty::node_id_to_type(ccx.tcx(), id);
2116 let avar = adt::represent_type(ccx, ty);
2118 adt::General(_, ref variants, _) => {
2119 for var in variants.iter() {
2121 for field in var.fields.iter().skip(1) {
2122 // skip the discriminant
2123 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2128 _ => { /* its size is either constant or unimportant */ }
2131 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2132 |(l, s, li), (idx, &size)|
2135 } else if size > s {
2143 let llty = type_of::sizing_type_of(ccx, ty);
2145 let sess = &ccx.tcx().sess;
2146 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2148 adt::General(..) => {
2149 for (i, var) in enum_def.variants.iter().enumerate() {
2150 ccx.tcx().sess.span_note(var.span,
2151 &*format!("variant data: {} bytes", sizes[i]));
2158 // we only warn if the largest variant is at least thrice as large as
2159 // the second-largest.
2160 if !is_allow && largest > slargest * 3 && slargest > 0 {
2161 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2162 // pass for the latter already ran.
2163 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
2164 *lvlsrc.unwrap(), Some(sp),
2165 &format!("enum variant is more than three times larger \
2166 ({} bytes) than the next largest (ignoring padding)",
2169 ccx.sess().span_note(enum_def.variants[largest_index].span,
2170 "this variant is the largest");
2174 pub struct TransItemVisitor<'a, 'tcx: 'a> {
2175 pub ccx: &'a CrateContext<'a, 'tcx>,
2178 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemVisitor<'a, 'tcx> {
2179 fn visit_item(&mut self, i: &ast::Item) {
2180 trans_item(self.ccx, i);
2184 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2185 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2186 // applicable to variable declarations and may not really make sense for
2187 // Rust code in the first place but whitelist them anyway and trust that
2188 // the user knows what s/he's doing. Who knows, unanticipated use cases
2189 // may pop up in the future.
2191 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2192 // and don't have to be, LLVM treats them as no-ops.
2194 "appending" => Some(llvm::AppendingLinkage),
2195 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2196 "common" => Some(llvm::CommonLinkage),
2197 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2198 "external" => Some(llvm::ExternalLinkage),
2199 "internal" => Some(llvm::InternalLinkage),
2200 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2201 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2202 "private" => Some(llvm::PrivateLinkage),
2203 "weak" => Some(llvm::WeakAnyLinkage),
2204 "weak_odr" => Some(llvm::WeakODRLinkage),
2210 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2212 pub enum ValueOrigin {
2213 /// The LLVM `Value` is in this context because the corresponding item was
2214 /// assigned to the current compilation unit.
2215 OriginalTranslation,
2216 /// The `Value`'s corresponding item was assigned to some other compilation
2217 /// unit, but the `Value` was translated in this context anyway because the
2218 /// item is marked `#[inline]`.
2222 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2223 /// If the `llval` is the direct translation of a specific Rust item, `id`
2224 /// should be set to the `NodeId` of that item. (This mapping should be
2225 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2226 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2227 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2228 /// assigned to a different compilation unit.
2229 pub fn update_linkage(ccx: &CrateContext,
2231 id: Option<ast::NodeId>,
2232 llval_origin: ValueOrigin) {
2233 match llval_origin {
2235 // `llval` is a translation of an item defined in a separate
2236 // compilation unit. This only makes sense if there are at least
2237 // two compilation units.
2238 assert!(ccx.sess().opts.cg.codegen_units > 1);
2239 // `llval` is a copy of something defined elsewhere, so use
2240 // `AvailableExternallyLinkage` to avoid duplicating code in the
2242 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2245 OriginalTranslation => {},
2248 if let Some(id) = id {
2249 let item = ccx.tcx().map.get(id);
2250 if let ast_map::NodeItem(i) = item {
2251 if let Some(name) = attr::first_attr_value_str_by_name(i.attrs.as_slice(), "linkage") {
2252 if let Some(linkage) = llvm_linkage_by_name(name.get()) {
2253 llvm::SetLinkage(llval, linkage);
2255 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2263 Some(id) if ccx.reachable().contains(&id) => {
2264 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2267 // `id` does not refer to an item in `ccx.reachable`.
2268 if ccx.sess().opts.cg.codegen_units > 1 {
2269 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2271 llvm::SetLinkage(llval, llvm::InternalLinkage);
2277 pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
2278 let _icx = push_ctxt("trans_item");
2280 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2283 ast::ItemFn(ref decl, _fn_style, abi, ref generics, ref body) => {
2284 if !generics.is_type_parameterized() {
2285 let trans_everywhere = attr::requests_inline(&item.attrs[]);
2286 // Ignore `trans_everywhere` for cross-crate inlined items
2287 // (`from_external`). `trans_item` will be called once for each
2288 // compilation unit that references the item, so it will still get
2289 // translated everywhere it's needed.
2290 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2291 let llfn = get_item_val(ccx, item.id);
2293 foreign::trans_rust_fn_with_foreign_abi(ccx,
2298 &Substs::trans_empty(),
2306 &Substs::trans_empty(),
2313 if is_origin { OriginalTranslation } else { InlinedCopy });
2317 // Be sure to travel more than just one layer deep to catch nested
2318 // items in blocks and such.
2319 let mut v = TransItemVisitor{ ccx: ccx };
2320 v.visit_block(&**body);
2322 ast::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2323 meth::trans_impl(ccx,
2329 ast::ItemMod(ref m) => {
2330 trans_mod(&ccx.rotate(), m);
2332 ast::ItemEnum(ref enum_definition, ref gens) => {
2333 if gens.ty_params.is_empty() {
2334 // sizes only make sense for non-generic types
2336 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2339 ast::ItemConst(_, ref expr) => {
2340 // Recurse on the expression to catch items in blocks
2341 let mut v = TransItemVisitor{ ccx: ccx };
2342 v.visit_expr(&**expr);
2344 ast::ItemStatic(_, m, ref expr) => {
2345 // Recurse on the expression to catch items in blocks
2346 let mut v = TransItemVisitor{ ccx: ccx };
2347 v.visit_expr(&**expr);
2349 consts::trans_static(ccx, m, item.id);
2350 let g = get_item_val(ccx, item.id);
2351 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2353 // Do static_assert checking. It can't really be done much earlier
2354 // because we need to get the value of the bool out of LLVM
2355 if attr::contains_name(&item.attrs[], "static_assert") {
2356 if m == ast::MutMutable {
2357 ccx.sess().span_fatal(expr.span,
2358 "cannot have static_assert on a mutable \
2362 let v = ccx.static_values().borrow()[item.id].clone();
2364 if !(llvm::LLVMConstIntGetZExtValue(v) != 0) {
2365 ccx.sess().span_fatal(expr.span, "static assertion failed");
2370 ast::ItemForeignMod(ref foreign_mod) => {
2371 foreign::trans_foreign_mod(ccx, foreign_mod);
2373 ast::ItemTrait(..) => {
2374 // Inside of this trait definition, we won't be actually translating any
2375 // functions, but the trait still needs to be walked. Otherwise default
2376 // methods with items will not get translated and will cause ICE's when
2377 // metadata time comes around.
2378 let mut v = TransItemVisitor{ ccx: ccx };
2379 visit::walk_item(&mut v, item);
2381 _ => {/* fall through */ }
2385 // Translate a module. Doing this amounts to translating the items in the
2386 // module; there ends up being no artifact (aside from linkage names) of
2387 // separate modules in the compiled program. That's because modules exist
2388 // only as a convenience for humans working with the code, to organize names
2389 // and control visibility.
2390 pub fn trans_mod(ccx: &CrateContext, m: &ast::Mod) {
2391 let _icx = push_ctxt("trans_mod");
2392 for item in m.items.iter() {
2393 trans_item(ccx, &**item);
2397 fn finish_register_fn(ccx: &CrateContext, sp: Span, sym: String, node_id: ast::NodeId,
2399 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2401 // The stack exhaustion lang item shouldn't have a split stack because
2402 // otherwise it would continue to be exhausted (bad), and both it and the
2403 // eh_personality functions need to be externally linkable.
2404 let def = ast_util::local_def(node_id);
2405 if ccx.tcx().lang_items.stack_exhausted() == Some(def) {
2406 unset_split_stack(llfn);
2407 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2409 if ccx.tcx().lang_items.eh_personality() == Some(def) {
2410 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2414 if is_entry_fn(ccx.sess(), node_id) {
2415 create_entry_wrapper(ccx, sp, llfn);
2419 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2422 node_id: ast::NodeId,
2423 node_type: Ty<'tcx>)
2425 match node_type.sty {
2426 ty::ty_bare_fn(_, ref f) => {
2427 assert!(f.abi == Rust || f.abi == RustCall);
2429 _ => panic!("expected bare rust fn")
2432 let llfn = decl_rust_fn(ccx, node_type, &sym[]);
2433 finish_register_fn(ccx, sp, sym, node_id, llfn);
2437 pub fn get_fn_llvm_attributes<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>)
2438 -> llvm::AttrBuilder
2440 use middle::ty::{BrAnon, ReLateBound};
2443 let (fn_sig, abi, has_env) = match fn_ty.sty {
2444 ty::ty_bare_fn(_, ref f) => (&f.sig, f.abi, false),
2445 ty::ty_unboxed_closure(closure_did, _, substs) => {
2446 let typer = common::NormalizingUnboxedClosureTyper::new(ccx.tcx());
2447 function_type = typer.unboxed_closure_type(closure_did, substs);
2448 (&function_type.sig, RustCall, true)
2450 _ => ccx.sess().bug("expected closure or function.")
2453 let fn_sig = ty::erase_late_bound_regions(ccx.tcx(), fn_sig);
2455 // Since index 0 is the return value of the llvm func, we start
2456 // at either 1 or 2 depending on whether there's an env slot or not
2457 let mut first_arg_offset = if has_env { 2 } else { 1 };
2458 let mut attrs = llvm::AttrBuilder::new();
2459 let ret_ty = fn_sig.output;
2461 // These have an odd calling convention, so we need to manually
2462 // unpack the input ty's
2463 let input_tys = match fn_ty.sty {
2464 ty::ty_unboxed_closure(_, _, _) => {
2465 assert!(abi == RustCall);
2467 match fn_sig.inputs[0].sty {
2468 ty::ty_tup(ref inputs) => inputs.clone(),
2469 _ => ccx.sess().bug("expected tuple'd inputs")
2472 ty::ty_bare_fn(..) if abi == RustCall => {
2473 let mut inputs = vec![fn_sig.inputs[0]];
2475 match fn_sig.inputs[1].sty {
2476 ty::ty_tup(ref t_in) => {
2477 inputs.push_all(&t_in[]);
2480 _ => ccx.sess().bug("expected tuple'd inputs")
2483 _ => fn_sig.inputs.clone()
2486 if let ty::FnConverging(ret_ty) = ret_ty {
2487 // A function pointer is called without the declaration
2488 // available, so we have to apply any attributes with ABI
2489 // implications directly to the call instruction. Right now,
2490 // the only attribute we need to worry about is `sret`.
2491 if type_of::return_uses_outptr(ccx, ret_ty) {
2492 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, ret_ty));
2494 // The outptr can be noalias and nocapture because it's entirely
2495 // invisible to the program. We also know it's nonnull as well
2496 // as how many bytes we can dereference
2497 attrs.arg(1, llvm::StructRetAttribute)
2498 .arg(1, llvm::NoAliasAttribute)
2499 .arg(1, llvm::NoCaptureAttribute)
2500 .arg(1, llvm::DereferenceableAttribute(llret_sz));
2502 // Add one more since there's an outptr
2503 first_arg_offset += 1;
2505 // The `noalias` attribute on the return value is useful to a
2506 // function ptr caller.
2508 // `~` pointer return values never alias because ownership
2510 ty::ty_uniq(it) if !common::type_is_sized(ccx.tcx(), it) => {}
2512 attrs.ret(llvm::NoAliasAttribute);
2517 // We can also mark the return value as `dereferenceable` in certain cases
2519 // These are not really pointers but pairs, (pointer, len)
2521 ty::ty_rptr(_, ty::mt { ty: it, .. }) if !common::type_is_sized(ccx.tcx(), it) => {}
2522 ty::ty_uniq(inner) | ty::ty_rptr(_, ty::mt { ty: inner, .. }) => {
2523 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2524 attrs.ret(llvm::DereferenceableAttribute(llret_sz));
2529 if let ty::ty_bool = ret_ty.sty {
2530 attrs.ret(llvm::ZExtAttribute);
2535 for (idx, &t) in input_tys.iter().enumerate().map(|(i, v)| (i + first_arg_offset, v)) {
2537 // this needs to be first to prevent fat pointers from falling through
2538 _ if !type_is_immediate(ccx, t) => {
2539 let llarg_sz = llsize_of_real(ccx, type_of::type_of(ccx, t));
2541 // For non-immediate arguments the callee gets its own copy of
2542 // the value on the stack, so there are no aliases. It's also
2543 // program-invisible so can't possibly capture
2544 attrs.arg(idx, llvm::NoAliasAttribute)
2545 .arg(idx, llvm::NoCaptureAttribute)
2546 .arg(idx, llvm::DereferenceableAttribute(llarg_sz));
2550 attrs.arg(idx, llvm::ZExtAttribute);
2553 // `~` pointer parameters never alias because ownership is transferred
2554 ty::ty_uniq(inner) => {
2555 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2557 attrs.arg(idx, llvm::NoAliasAttribute)
2558 .arg(idx, llvm::DereferenceableAttribute(llsz));
2561 // `&mut` pointer parameters never alias other parameters, or mutable global data
2563 // `&T` where `T` contains no `UnsafeCell<U>` is immutable, and can be marked as both
2564 // `readonly` and `noalias`, as LLVM's definition of `noalias` is based solely on
2565 // memory dependencies rather than pointer equality
2566 ty::ty_rptr(b, mt) if mt.mutbl == ast::MutMutable ||
2567 !ty::type_contents(ccx.tcx(), mt.ty).interior_unsafe() => {
2569 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2570 attrs.arg(idx, llvm::NoAliasAttribute)
2571 .arg(idx, llvm::DereferenceableAttribute(llsz));
2573 if mt.mutbl == ast::MutImmutable {
2574 attrs.arg(idx, llvm::ReadOnlyAttribute);
2577 if let ReLateBound(_, BrAnon(_)) = *b {
2578 attrs.arg(idx, llvm::NoCaptureAttribute);
2582 // When a reference in an argument has no named lifetime, it's impossible for that
2583 // reference to escape this function (returned or stored beyond the call by a closure).
2584 ty::ty_rptr(&ReLateBound(_, BrAnon(_)), mt) => {
2585 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2586 attrs.arg(idx, llvm::NoCaptureAttribute)
2587 .arg(idx, llvm::DereferenceableAttribute(llsz));
2590 // & pointer parameters are also never null and we know exactly how
2591 // many bytes we can dereference
2592 ty::ty_rptr(_, mt) => {
2593 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2594 attrs.arg(idx, llvm::DereferenceableAttribute(llsz));
2603 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2604 pub fn register_fn_llvmty(ccx: &CrateContext,
2607 node_id: ast::NodeId,
2609 llfty: Type) -> ValueRef {
2610 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2612 let llfn = decl_fn(ccx,
2616 ty::FnConverging(ty::mk_nil(ccx.tcx())));
2617 finish_register_fn(ccx, sp, sym, node_id, llfn);
2621 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2622 match *sess.entry_fn.borrow() {
2623 Some((entry_id, _)) => node_id == entry_id,
2628 // Create a _rust_main(args: ~[str]) function which will be called from the
2629 // runtime rust_start function
2630 pub fn create_entry_wrapper(ccx: &CrateContext,
2632 main_llfn: ValueRef) {
2633 let et = ccx.sess().entry_type.get().unwrap();
2635 config::EntryMain => {
2636 create_entry_fn(ccx, main_llfn, true);
2638 config::EntryStart => create_entry_fn(ccx, main_llfn, false),
2639 config::EntryNone => {} // Do nothing.
2642 fn create_entry_fn(ccx: &CrateContext,
2643 rust_main: ValueRef,
2644 use_start_lang_item: bool) {
2645 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2648 let llfn = decl_cdecl_fn(ccx, "main", llfty, ty::mk_nil(ccx.tcx()));
2650 // FIXME: #16581: Marking a symbol in the executable with `dllexport`
2651 // linkage forces MinGW's linker to output a `.reloc` section for ASLR
2652 if ccx.sess().target.target.options.is_like_windows {
2653 unsafe { llvm::LLVMRustSetDLLExportStorageClass(llfn) }
2657 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn,
2658 "top\0".as_ptr() as *const _)
2660 let bld = ccx.raw_builder();
2662 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2664 debuginfo::insert_reference_to_gdb_debug_scripts_section_global(ccx);
2666 let (start_fn, args) = if use_start_lang_item {
2667 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2669 Err(s) => { ccx.sess().fatal(&s[]); }
2671 let start_fn = if start_def_id.krate == ast::LOCAL_CRATE {
2672 get_item_val(ccx, start_def_id.node)
2674 let start_fn_type = csearch::get_type(ccx.tcx(),
2676 trans_external_path(ccx, start_def_id, start_fn_type)
2680 let opaque_rust_main = llvm::LLVMBuildPointerCast(bld,
2681 rust_main, Type::i8p(ccx).to_ref(),
2682 "rust_main\0".as_ptr() as *const _);
2692 debug!("using user-defined start fn");
2694 get_param(llfn, 0 as c_uint),
2695 get_param(llfn, 1 as c_uint)
2701 let result = llvm::LLVMBuildCall(bld,
2704 args.len() as c_uint,
2707 llvm::LLVMBuildRet(bld, result);
2712 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, id: ast::NodeId,
2713 ty: Ty<'tcx>, attrs: &[ast::Attribute]) -> String {
2714 match ccx.external_srcs().borrow().get(&id) {
2716 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2717 debug!("found item {} in other crate...", sym);
2723 match attr::first_attr_value_str_by_name(attrs, "export_name") {
2724 // Use provided name
2725 Some(name) => name.get().to_string(),
2727 _ => ccx.tcx().map.with_path(id, |path| {
2728 if attr::contains_name(attrs, "no_mangle") {
2730 path.last().unwrap().to_string()
2732 match weak_lang_items::link_name(attrs) {
2733 Some(name) => name.get().to_string(),
2735 // Usual name mangling
2736 mangle_exported_name(ccx, path, ty, id)
2744 fn contains_null(s: &str) -> bool {
2745 s.bytes().any(|b| b == 0)
2748 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2749 debug!("get_item_val(id=`{}`)", id);
2751 match ccx.item_vals().borrow().get(&id).cloned() {
2752 Some(v) => return v,
2756 let item = ccx.tcx().map.get(id);
2757 debug!("get_item_val: id={} item={:?}", id, item);
2758 let val = match item {
2759 ast_map::NodeItem(i) => {
2760 let ty = ty::node_id_to_type(ccx.tcx(), i.id);
2761 let sym = |&:| exported_name(ccx, id, ty, &i.attrs[]);
2763 let v = match i.node {
2764 ast::ItemStatic(_, _, ref expr) => {
2765 // If this static came from an external crate, then
2766 // we need to get the symbol from csearch instead of
2767 // using the current crate's name/version
2768 // information in the hash of the symbol
2770 debug!("making {}", sym);
2772 // We need the translated value here, because for enums the
2773 // LLVM type is not fully determined by the Rust type.
2774 let (v, ty) = consts::const_expr(ccx, &**expr);
2775 ccx.static_values().borrow_mut().insert(id, v);
2777 // boolean SSA values are i1, but they have to be stored in i8 slots,
2778 // otherwise some LLVM optimization passes don't work as expected
2779 let llty = if ty::type_is_bool(ty) {
2780 llvm::LLVMInt8TypeInContext(ccx.llcx())
2784 if contains_null(&sym[]) {
2786 &format!("Illegal null byte in export_name \
2787 value: `{}`", sym)[]);
2789 let buf = CString::from_slice(sym.as_bytes());
2790 let g = llvm::LLVMAddGlobal(ccx.llmod(), llty,
2793 if attr::contains_name(&i.attrs[],
2795 llvm::set_thread_local(g, true);
2797 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2802 ast::ItemConst(_, ref expr) => {
2803 let (v, _) = consts::const_expr(ccx, &**expr);
2804 ccx.const_values().borrow_mut().insert(id, v);
2808 ast::ItemFn(_, _, abi, _, _) => {
2810 let llfn = if abi == Rust {
2811 register_fn(ccx, i.span, sym, i.id, ty)
2813 foreign::register_rust_fn_with_foreign_abi(ccx,
2818 set_llvm_fn_attrs(ccx, &i.attrs[], llfn);
2822 _ => panic!("get_item_val: weird result in table")
2825 match attr::first_attr_value_str_by_name(&i.attrs[],
2828 if contains_null(sect.get()) {
2829 ccx.sess().fatal(&format!("Illegal null byte in link_section value: `{}`",
2833 let buf = CString::from_slice(sect.get().as_bytes());
2834 llvm::LLVMSetSection(v, buf.as_ptr());
2843 ast_map::NodeTraitItem(trait_method) => {
2844 debug!("get_item_val(): processing a NodeTraitItem");
2845 match *trait_method {
2846 ast::RequiredMethod(_) | ast::TypeTraitItem(_) => {
2847 ccx.sess().bug("unexpected variant: required trait \
2848 method in get_item_val()");
2850 ast::ProvidedMethod(ref m) => {
2851 register_method(ccx, id, &**m)
2856 ast_map::NodeImplItem(ii) => {
2858 ast::MethodImplItem(ref m) => register_method(ccx, id, &**m),
2859 ast::TypeImplItem(ref typedef) => {
2860 ccx.sess().span_bug(typedef.span,
2861 "unexpected variant: required impl \
2862 method in get_item_val()")
2867 ast_map::NodeForeignItem(ni) => {
2869 ast::ForeignItemFn(..) => {
2870 let abi = ccx.tcx().map.get_foreign_abi(id);
2871 let ty = ty::node_id_to_type(ccx.tcx(), ni.id);
2872 let name = foreign::link_name(&*ni);
2873 foreign::register_foreign_item_fn(ccx, abi, ty, &name.get()[])
2875 ast::ForeignItemStatic(..) => {
2876 foreign::register_static(ccx, &*ni)
2881 ast_map::NodeVariant(ref v) => {
2883 let args = match v.node.kind {
2884 ast::TupleVariantKind(ref args) => args,
2885 ast::StructVariantKind(_) => {
2886 panic!("struct variant kind unexpected in get_item_val")
2889 assert!(args.len() != 0u);
2890 let ty = ty::node_id_to_type(ccx.tcx(), id);
2891 let parent = ccx.tcx().map.get_parent(id);
2892 let enm = ccx.tcx().map.expect_item(parent);
2893 let sym = exported_name(ccx,
2898 llfn = match enm.node {
2899 ast::ItemEnum(_, _) => {
2900 register_fn(ccx, (*v).span, sym, id, ty)
2902 _ => panic!("NodeVariant, shouldn't happen")
2904 set_inline_hint(llfn);
2908 ast_map::NodeStructCtor(struct_def) => {
2909 // Only register the constructor if this is a tuple-like struct.
2910 let ctor_id = match struct_def.ctor_id {
2912 ccx.sess().bug("attempt to register a constructor of \
2913 a non-tuple-like struct")
2915 Some(ctor_id) => ctor_id,
2917 let parent = ccx.tcx().map.get_parent(id);
2918 let struct_item = ccx.tcx().map.expect_item(parent);
2919 let ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2920 let sym = exported_name(ccx,
2923 &struct_item.attrs[]);
2924 let llfn = register_fn(ccx, struct_item.span,
2926 set_inline_hint(llfn);
2931 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}",
2936 // All LLVM globals and functions are initially created as external-linkage
2937 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2938 // into a definition, it adjusts the linkage then (using `update_linkage`).
2940 // The exception is foreign items, which have their linkage set inside the
2941 // call to `foreign::register_*` above. We don't touch the linkage after
2942 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2943 // other item translation functions do).
2945 ccx.item_vals().borrow_mut().insert(id, val);
2949 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2950 m: &ast::Method) -> ValueRef {
2951 let mty = ty::node_id_to_type(ccx.tcx(), id);
2953 let sym = exported_name(ccx, id, mty, &m.attrs[]);
2955 let llfn = register_fn(ccx, m.span, sym, id, mty);
2956 set_llvm_fn_attrs(ccx, &m.attrs[], llfn);
2960 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'tcx>,
2961 ie: encoder::EncodeInlinedItem<'a>)
2962 -> encoder::EncodeParams<'a, 'tcx> {
2963 encoder::EncodeParams {
2964 diag: cx.sess().diagnostic(),
2966 reexports: cx.export_map(),
2967 item_symbols: cx.item_symbols(),
2968 link_meta: cx.link_meta(),
2969 cstore: &cx.sess().cstore,
2970 encode_inlined_item: ie,
2971 reachable: cx.reachable(),
2975 pub fn write_metadata(cx: &SharedCrateContext, krate: &ast::Crate) -> Vec<u8> {
2978 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2979 *ty != config::CrateTypeExecutable
2985 let encode_inlined_item: encoder::EncodeInlinedItem =
2986 box |ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii);
2988 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item);
2989 let metadata = encoder::encode_metadata(encode_parms, krate);
2990 let mut compressed = encoder::metadata_encoding_version.to_vec();
2991 compressed.push_all(match flate::deflate_bytes(metadata.as_slice()) {
2992 Some(compressed) => compressed,
2993 None => cx.sess().fatal("failed to compress metadata"),
2995 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[]);
2996 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2997 let name = format!("rust_metadata_{}_{}",
2998 cx.link_meta().crate_name,
2999 cx.link_meta().crate_hash);
3000 let buf = CString::from_vec(name.into_bytes());
3001 let llglobal = unsafe {
3002 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(),
3006 llvm::LLVMSetInitializer(llglobal, llconst);
3007 let name = loader::meta_section_name(cx.sess().target.target.options.is_like_osx);
3008 let name = CString::from_slice(name.as_bytes());
3009 llvm::LLVMSetSection(llglobal, name.as_ptr())
3014 /// Find any symbols that are defined in one compilation unit, but not declared
3015 /// in any other compilation unit. Give these symbols internal linkage.
3016 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<String>) {
3018 let mut declared = HashSet::new();
3020 let iter_globals = |&: llmod| {
3022 cur: llvm::LLVMGetFirstGlobal(llmod),
3023 step: llvm::LLVMGetNextGlobal,
3027 let iter_functions = |&: llmod| {
3029 cur: llvm::LLVMGetFirstFunction(llmod),
3030 step: llvm::LLVMGetNextFunction,
3034 // Collect all external declarations in all compilation units.
3035 for ccx in cx.iter() {
3036 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3037 let linkage = llvm::LLVMGetLinkage(val);
3038 // We only care about external declarations (not definitions)
3039 // and available_externally definitions.
3040 if !(linkage == llvm::ExternalLinkage as c_uint &&
3041 llvm::LLVMIsDeclaration(val) != 0) &&
3042 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
3046 let name = ffi::c_str_to_bytes(&llvm::LLVMGetValueName(val))
3048 declared.insert(name);
3052 // Examine each external definition. If the definition is not used in
3053 // any other compilation unit, and is not reachable from other crates,
3054 // then give it internal linkage.
3055 for ccx in cx.iter() {
3056 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3057 // We only care about external definitions.
3058 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
3059 llvm::LLVMIsDeclaration(val) == 0) {
3063 let name = ffi::c_str_to_bytes(&llvm::LLVMGetValueName(val))
3065 if !declared.contains(&name) &&
3066 !reachable.contains(str::from_utf8(name.as_slice()).unwrap()) {
3067 llvm::SetLinkage(val, llvm::InternalLinkage);
3076 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
3079 impl Iterator for ValueIter {
3080 type Item = ValueRef;
3082 fn next(&mut self) -> Option<ValueRef> {
3086 let step: unsafe extern "C" fn(ValueRef) -> ValueRef =
3087 mem::transmute_copy(&self.step);
3098 pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
3099 -> (ty::ctxt<'tcx>, CrateTranslation) {
3100 let ty::CrateAnalysis { ty_cx: tcx, export_map, reachable, name, .. } = analysis;
3101 let krate = tcx.map.krate();
3103 // Before we touch LLVM, make sure that multithreading is enabled.
3105 use std::sync::{Once, ONCE_INIT};
3106 static INIT: Once = ONCE_INIT;
3107 static mut POISONED: bool = false;
3109 if llvm::LLVMStartMultithreaded() != 1 {
3110 // use an extra bool to make sure that all future usage of LLVM
3111 // cannot proceed despite the Once not running more than once.
3117 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3121 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3123 let codegen_units = tcx.sess.opts.cg.codegen_units;
3124 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name[],
3133 let ccx = shared_ccx.get_ccx(0);
3135 // First, verify intrinsics.
3136 intrinsic::check_intrinsics(&ccx);
3138 // Next, translate the module.
3140 let _icx = push_ctxt("text");
3141 trans_mod(&ccx, &krate.module);
3145 for ccx in shared_ccx.iter() {
3146 glue::emit_tydescs(&ccx);
3147 if ccx.sess().opts.debuginfo != NoDebugInfo {
3148 debuginfo::finalize(&ccx);
3152 // Translate the metadata.
3153 let metadata = write_metadata(&shared_ccx, krate);
3155 if shared_ccx.sess().trans_stats() {
3156 let stats = shared_ccx.stats();
3157 println!("--- trans stats ---");
3158 println!("n_static_tydescs: {}", stats.n_static_tydescs.get());
3159 println!("n_glues_created: {}", stats.n_glues_created.get());
3160 println!("n_null_glues: {}", stats.n_null_glues.get());
3161 println!("n_real_glues: {}", stats.n_real_glues.get());
3163 println!("n_fns: {}", stats.n_fns.get());
3164 println!("n_monos: {}", stats.n_monos.get());
3165 println!("n_inlines: {}", stats.n_inlines.get());
3166 println!("n_closures: {}", stats.n_closures.get());
3167 println!("fn stats:");
3168 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3169 insns_b.cmp(&insns_a)
3171 for tuple in stats.fn_stats.borrow().iter() {
3173 (ref name, insns) => {
3174 println!("{} insns, {}", insns, *name);
3179 if shared_ccx.sess().count_llvm_insns() {
3180 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3181 println!("{:7} {}", *v, *k);
3185 let modules = shared_ccx.iter()
3186 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3189 let mut reachable: Vec<String> = shared_ccx.reachable().iter().filter_map(|id| {
3190 shared_ccx.item_symbols().borrow().get(id).map(|s| s.to_string())
3193 // For the purposes of LTO, we add to the reachable set all of the upstream
3194 // reachable extern fns. These functions are all part of the public ABI of
3195 // the final product, so LTO needs to preserve them.
3196 shared_ccx.sess().cstore.iter_crate_data(|cnum, _| {
3197 let syms = csearch::get_reachable_extern_fns(&shared_ccx.sess().cstore, cnum);
3198 reachable.extend(syms.into_iter().map(|did| {
3199 csearch::get_symbol(&shared_ccx.sess().cstore, did)
3203 // Make sure that some other crucial symbols are not eliminated from the
3204 // module. This includes the main function, the crate map (used for debug
3205 // log settings and I/O), and finally the curious rust_stack_exhausted
3206 // symbol. This symbol is required for use by the libmorestack library that
3207 // we link in, so we must ensure that this symbol is not internalized (if
3208 // defined in the crate).
3209 reachable.push("main".to_string());
3210 reachable.push("rust_stack_exhausted".to_string());
3212 // referenced from .eh_frame section on some platforms
3213 reachable.push("rust_eh_personality".to_string());
3214 // referenced from rt/rust_try.ll
3215 reachable.push("rust_eh_personality_catch".to_string());
3217 if codegen_units > 1 {
3218 internalize_symbols(&shared_ccx, &reachable.iter().map(|x| x.clone()).collect());
3221 let metadata_module = ModuleTranslation {
3222 llcx: shared_ccx.metadata_llcx(),
3223 llmod: shared_ccx.metadata_llmod(),
3225 let formats = shared_ccx.tcx().dependency_formats.borrow().clone();
3226 let no_builtins = attr::contains_name(&krate.attrs[], "no_builtins");
3228 let translation = CrateTranslation {
3230 metadata_module: metadata_module,
3233 reachable: reachable,
3234 crate_formats: formats,
3235 no_builtins: no_builtins,
3238 (shared_ccx.take_tcx(), translation)