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, ClosureTyper};
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::{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;
69 use trans::debuginfo::{self, DebugLoc};
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_closure<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
259 closure_id: ast::DefId,
263 let closure_kind = ccx.tcx().closure_kind(closure_id);
265 ty::FnClosureKind => {
266 ty::mk_imm_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
268 ty::FnMutClosureKind => {
269 ty::mk_mut_rptr(ccx.tcx(), ccx.tcx().mk_region(ty::ReStatic), fn_ty)
271 ty::FnOnceClosureKind => fn_ty
275 pub fn kind_for_closure(ccx: &CrateContext, closure_id: ast::DefId) -> ty::ClosureKind {
276 ccx.tcx().closure_kinds.borrow()[closure_id]
279 pub fn decl_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
280 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
281 debug!("decl_rust_fn(fn_ty={}, name={:?})",
282 fn_ty.repr(ccx.tcx()),
285 let fn_ty = monomorphize::normalize_associated_type(ccx.tcx(), &fn_ty);
287 debug!("decl_rust_fn: fn_ty={} (after normalized associated types)",
288 fn_ty.repr(ccx.tcx()));
290 let function_type; // placeholder so that the memory ownership works out ok
292 let (sig, abi, env) = match fn_ty.sty {
293 ty::ty_bare_fn(_, ref f) => {
294 (&f.sig, f.abi, None)
296 ty::ty_closure(closure_did, _, substs) => {
297 let typer = common::NormalizingClosureTyper::new(ccx.tcx());
298 function_type = typer.closure_type(closure_did, substs);
299 let self_type = self_type_for_closure(ccx, closure_did, fn_ty);
300 let llenvironment_type = type_of_explicit_arg(ccx, self_type);
301 debug!("decl_rust_fn: function_type={} self_type={}",
302 function_type.repr(ccx.tcx()),
303 self_type.repr(ccx.tcx()));
304 (&function_type.sig, RustCall, Some(llenvironment_type))
306 _ => panic!("expected closure or fn")
309 let sig = ty::erase_late_bound_regions(ccx.tcx(), sig);
310 let sig = ty::Binder(sig);
312 debug!("decl_rust_fn: sig={} (after erasing regions)",
313 sig.repr(ccx.tcx()));
315 let llfty = type_of_rust_fn(ccx, env, &sig, abi);
317 debug!("decl_rust_fn: llfty={}",
318 ccx.tn().type_to_string(llfty));
320 let llfn = decl_fn(ccx, name, llvm::CCallConv, llfty, sig.0.output /* (1) */);
321 let attrs = get_fn_llvm_attributes(ccx, fn_ty);
322 attrs.apply_llfn(llfn);
324 // (1) it's ok to directly access sig.0.output because we erased all late-bound-regions above
329 pub fn decl_internal_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
330 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
331 let llfn = decl_rust_fn(ccx, fn_ty, name);
332 llvm::SetLinkage(llfn, llvm::InternalLinkage);
336 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: ast::DefId,
337 t: Ty<'tcx>) -> ValueRef {
338 let name = csearch::get_symbol(&ccx.sess().cstore, did);
339 let ty = type_of(ccx, t);
340 match ccx.externs().borrow_mut().get(&name) {
341 Some(n) => return *n,
345 let buf = CString::from_slice(name.as_bytes());
346 let c = llvm::LLVMAddGlobal(ccx.llmod(), ty.to_ref(), buf.as_ptr());
347 // Thread-local statics in some other crate need to *always* be linked
348 // against in a thread-local fashion, so we need to be sure to apply the
349 // thread-local attribute locally if it was present remotely. If we
350 // don't do this then linker errors can be generated where the linker
351 // complains that one object files has a thread local version of the
352 // symbol and another one doesn't.
353 for attr in &*ty::get_attrs(ccx.tcx(), did) {
354 if attr.check_name("thread_local") {
355 llvm::set_thread_local(c, true);
358 ccx.externs().borrow_mut().insert(name.to_string(), c);
363 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
364 info_ty: Ty<'tcx>, it: LangItem) -> ast::DefId {
365 match bcx.tcx().lang_items.require(it) {
368 bcx.sess().fatal(&format!("allocation of `{}` {}",
369 bcx.ty_to_string(info_ty),
375 // The following malloc_raw_dyn* functions allocate a box to contain
376 // a given type, but with a potentially dynamic size.
378 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
383 -> Result<'blk, 'tcx> {
384 let _icx = push_ctxt("malloc_raw_exchange");
387 let r = callee::trans_lang_call(bcx,
388 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
392 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
395 // Type descriptor and type glue stuff
397 pub fn get_tydesc<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
398 t: Ty<'tcx>) -> Rc<tydesc_info<'tcx>> {
399 match ccx.tydescs().borrow().get(&t) {
400 Some(inf) => return inf.clone(),
404 ccx.stats().n_static_tydescs.set(ccx.stats().n_static_tydescs.get() + 1);
405 let inf = Rc::new(glue::declare_tydesc(ccx, t));
407 ccx.tydescs().borrow_mut().insert(t, inf.clone());
411 #[allow(dead_code)] // useful
412 pub fn set_optimize_for_size(f: ValueRef) {
413 llvm::SetFunctionAttribute(f, llvm::OptimizeForSizeAttribute)
416 pub fn set_no_inline(f: ValueRef) {
417 llvm::SetFunctionAttribute(f, llvm::NoInlineAttribute)
420 #[allow(dead_code)] // useful
421 pub fn set_no_unwind(f: ValueRef) {
422 llvm::SetFunctionAttribute(f, llvm::NoUnwindAttribute)
425 // Tell LLVM to emit the information necessary to unwind the stack for the
427 pub fn set_uwtable(f: ValueRef) {
428 llvm::SetFunctionAttribute(f, llvm::UWTableAttribute)
431 pub fn set_inline_hint(f: ValueRef) {
432 llvm::SetFunctionAttribute(f, llvm::InlineHintAttribute)
435 pub fn set_llvm_fn_attrs(ccx: &CrateContext, attrs: &[ast::Attribute], llfn: ValueRef) {
437 // Set the inline hint if there is one
438 match find_inline_attr(attrs) {
439 InlineHint => set_inline_hint(llfn),
440 InlineAlways => set_always_inline(llfn),
441 InlineNever => set_no_inline(llfn),
442 InlineNone => { /* fallthrough */ }
447 match attr.name().get() {
448 "no_stack_check" => unset_split_stack(llfn),
449 "no_split_stack" => {
450 unset_split_stack(llfn);
451 ccx.sess().span_warn(attr.span,
452 "no_split_stack is a deprecated synonym for no_stack_check");
455 llvm::LLVMAddFunctionAttribute(llfn,
456 llvm::FunctionIndex as c_uint,
457 llvm::ColdAttribute as uint64_t)
462 attr::mark_used(attr);
467 pub fn set_always_inline(f: ValueRef) {
468 llvm::SetFunctionAttribute(f, llvm::AlwaysInlineAttribute)
471 pub fn set_split_stack(f: ValueRef) {
473 llvm::LLVMAddFunctionAttrString(f, llvm::FunctionIndex as c_uint,
474 "split-stack\0".as_ptr() as *const _);
478 pub fn unset_split_stack(f: ValueRef) {
480 llvm::LLVMRemoveFunctionAttrString(f, llvm::FunctionIndex as c_uint,
481 "split-stack\0".as_ptr() as *const _);
485 // Double-check that we never ask LLVM to declare the same symbol twice. It
486 // silently mangles such symbols, breaking our linkage model.
487 pub fn note_unique_llvm_symbol(ccx: &CrateContext, sym: String) {
488 if ccx.all_llvm_symbols().borrow().contains(&sym) {
489 ccx.sess().bug(&format!("duplicate LLVM symbol: {}", sym)[]);
491 ccx.all_llvm_symbols().borrow_mut().insert(sym);
495 pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
498 parent_id: ast::DefId,
499 substs: &subst::Substs<'tcx>)
501 let _icx = push_ctxt("trans_res_dtor");
502 let did = inline::maybe_instantiate_inline(ccx, did);
504 if !substs.types.is_empty() {
505 assert_eq!(did.krate, ast::LOCAL_CRATE);
507 // Since we're in trans we don't care for any region parameters
508 let substs = subst::Substs::erased(substs.types.clone());
510 let (val, _, _) = monomorphize::monomorphic_fn(ccx, did, &substs, None);
513 } else if did.krate == ast::LOCAL_CRATE {
514 get_item_val(ccx, did.node)
517 let name = csearch::get_symbol(&ccx.sess().cstore, did);
518 let class_ty = ty::lookup_item_type(tcx, parent_id).ty.subst(tcx, substs);
519 let llty = type_of_dtor(ccx, class_ty);
520 let dtor_ty = ty::mk_ctor_fn(ccx.tcx(),
522 &[glue::get_drop_glue_type(ccx, t)],
523 ty::mk_nil(ccx.tcx()));
525 &mut *ccx.externs().borrow_mut(),
533 // Used only for creating scalar comparison glue.
535 pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
537 pub fn compare_scalar_types<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
542 -> Result<'blk, 'tcx> {
543 let f = |&: a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op));
546 ty::ty_tup(ref tys) if tys.is_empty() => f(nil_type),
547 ty::ty_bool | ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
548 ty::ty_ptr(mt) if common::type_is_sized(cx.tcx(), mt.ty) => f(unsigned_int),
549 ty::ty_int(_) => f(signed_int),
550 ty::ty_float(_) => f(floating_point),
551 // Should never get here, because t is scalar.
552 _ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
557 // A helper function to do the actual comparison of scalar values.
558 pub fn compare_scalar_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
564 let _icx = push_ctxt("compare_scalar_values");
565 fn die(cx: Block) -> ! {
566 cx.sess().bug("compare_scalar_values: must be a comparison operator");
570 // We don't need to do actual comparisons for nil.
571 // () == () holds but () < () does not.
573 ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(cx.ccx(), true),
574 ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(cx.ccx(), false),
575 // refinements would be nice
581 ast::BiEq => llvm::RealOEQ,
582 ast::BiNe => llvm::RealUNE,
583 ast::BiLt => llvm::RealOLT,
584 ast::BiLe => llvm::RealOLE,
585 ast::BiGt => llvm::RealOGT,
586 ast::BiGe => llvm::RealOGE,
589 return FCmp(cx, cmp, lhs, rhs);
593 ast::BiEq => llvm::IntEQ,
594 ast::BiNe => llvm::IntNE,
595 ast::BiLt => llvm::IntSLT,
596 ast::BiLe => llvm::IntSLE,
597 ast::BiGt => llvm::IntSGT,
598 ast::BiGe => llvm::IntSGE,
601 return ICmp(cx, cmp, lhs, rhs);
605 ast::BiEq => llvm::IntEQ,
606 ast::BiNe => llvm::IntNE,
607 ast::BiLt => llvm::IntULT,
608 ast::BiLe => llvm::IntULE,
609 ast::BiGt => llvm::IntUGT,
610 ast::BiGe => llvm::IntUGE,
613 return ICmp(cx, cmp, lhs, rhs);
618 pub fn compare_simd_types<'blk, 'tcx>(
619 cx: Block<'blk, 'tcx>,
626 let cmp = match t.sty {
628 // The comparison operators for floating point vectors are challenging.
629 // LLVM outputs a `< size x i1 >`, but if we perform a sign extension
630 // then bitcast to a floating point vector, the result will be `-NaN`
631 // for each truth value. Because of this they are unsupported.
632 cx.sess().bug("compare_simd_types: comparison operators \
633 not supported for floating point SIMD types")
635 ty::ty_uint(_) => match op.node {
636 ast::BiEq => llvm::IntEQ,
637 ast::BiNe => llvm::IntNE,
638 ast::BiLt => llvm::IntULT,
639 ast::BiLe => llvm::IntULE,
640 ast::BiGt => llvm::IntUGT,
641 ast::BiGe => llvm::IntUGE,
642 _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
644 ty::ty_int(_) => match op.node {
645 ast::BiEq => llvm::IntEQ,
646 ast::BiNe => llvm::IntNE,
647 ast::BiLt => llvm::IntSLT,
648 ast::BiLe => llvm::IntSLE,
649 ast::BiGt => llvm::IntSGT,
650 ast::BiGe => llvm::IntSGE,
651 _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
653 _ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
655 let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
656 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
657 // to get the correctly sized type. This will compile to a single instruction
658 // once the IR is converted to assembly if the SIMD instruction is supported
659 // by the target architecture.
660 SExt(cx, ICmp(cx, cmp, lhs, rhs), return_ty)
663 // Iterates through the elements of a structural type.
664 pub fn iter_structural_ty<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
668 -> Block<'blk, 'tcx> where
669 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
671 let _icx = push_ctxt("iter_structural_ty");
673 fn iter_variant<'blk, 'tcx, F>(cx: Block<'blk, 'tcx>,
674 repr: &adt::Repr<'tcx>,
676 variant: &ty::VariantInfo<'tcx>,
677 substs: &subst::Substs<'tcx>,
679 -> Block<'blk, 'tcx> where
680 F: FnMut(Block<'blk, 'tcx>, ValueRef, Ty<'tcx>) -> Block<'blk, 'tcx>,
682 let _icx = push_ctxt("iter_variant");
686 for (i, &arg) in variant.args.iter().enumerate() {
687 let arg = monomorphize::apply_param_substs(tcx, substs, &arg);
688 cx = f(cx, adt::trans_field_ptr(cx, repr, av, variant.disr_val, i), arg);
693 let (data_ptr, info) = if common::type_is_sized(cx.tcx(), t) {
696 let data = GEPi(cx, av, &[0, abi::FAT_PTR_ADDR]);
697 let info = GEPi(cx, av, &[0, abi::FAT_PTR_EXTRA]);
698 (Load(cx, data), Some(Load(cx, info)))
703 ty::ty_struct(..) => {
704 let repr = adt::represent_type(cx.ccx(), t);
705 expr::with_field_tys(cx.tcx(), t, None, |discr, field_tys| {
706 for (i, field_ty) in field_tys.iter().enumerate() {
707 let field_ty = field_ty.mt.ty;
708 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
710 let val = if common::type_is_sized(cx.tcx(), field_ty) {
713 let boxed_ty = ty::mk_open(cx.tcx(), field_ty);
714 let scratch = datum::rvalue_scratch_datum(cx, boxed_ty, "__fat_ptr_iter");
715 Store(cx, llfld_a, GEPi(cx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
716 Store(cx, info.unwrap(), GEPi(cx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
719 cx = f(cx, val, field_ty);
723 ty::ty_closure(def_id, _, substs) => {
724 let repr = adt::represent_type(cx.ccx(), t);
725 let typer = common::NormalizingClosureTyper::new(cx.tcx());
726 let upvars = typer.closure_upvars(def_id, substs).unwrap();
727 for (i, upvar) in upvars.iter().enumerate() {
728 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
729 cx = f(cx, llupvar, upvar.ty);
732 ty::ty_vec(_, Some(n)) => {
733 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
734 let unit_ty = ty::sequence_element_type(cx.tcx(), t);
735 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
737 ty::ty_tup(ref args) => {
738 let repr = adt::represent_type(cx.ccx(), t);
739 for (i, arg) in args.iter().enumerate() {
740 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
741 cx = f(cx, llfld_a, *arg);
744 ty::ty_enum(tid, substs) => {
748 let repr = adt::represent_type(ccx, t);
749 let variants = ty::enum_variants(ccx.tcx(), tid);
750 let n_variants = (*variants).len();
752 // NB: we must hit the discriminant first so that structural
753 // comparison know not to proceed when the discriminants differ.
755 match adt::trans_switch(cx, &*repr, av) {
756 (_match::Single, None) => {
757 cx = iter_variant(cx, &*repr, av, &*(*variants)[0],
760 (_match::Switch, Some(lldiscrim_a)) => {
761 cx = f(cx, lldiscrim_a, cx.tcx().types.int);
762 let unr_cx = fcx.new_temp_block("enum-iter-unr");
764 let llswitch = Switch(cx, lldiscrim_a, unr_cx.llbb,
766 let next_cx = fcx.new_temp_block("enum-iter-next");
768 for variant in &(*variants) {
771 &format!("enum-iter-variant-{}",
772 &variant.disr_val.to_string()[])
774 match adt::trans_case(cx, &*repr, variant.disr_val) {
775 _match::SingleResult(r) => {
776 AddCase(llswitch, r.val, variant_cx.llbb)
778 _ => ccx.sess().unimpl("value from adt::trans_case \
779 in iter_structural_ty")
782 iter_variant(variant_cx,
788 Br(variant_cx, next_cx.llbb, DebugLoc::None);
792 _ => ccx.sess().unimpl("value from adt::trans_switch \
793 in iter_structural_ty")
797 cx.sess().unimpl(&format!("type in iter_structural_ty: {}",
798 ty_to_string(cx.tcx(), t))[])
804 pub fn cast_shift_expr_rhs(cx: Block,
809 cast_shift_rhs(op, lhs, rhs,
810 |a,b| Trunc(cx, a, b),
811 |a,b| ZExt(cx, a, b))
814 pub fn cast_shift_const_rhs(op: ast::BinOp,
815 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
816 cast_shift_rhs(op, lhs, rhs,
817 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
818 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
821 pub fn cast_shift_rhs<F, G>(op: ast::BinOp,
827 F: FnOnce(ValueRef, Type) -> ValueRef,
828 G: FnOnce(ValueRef, Type) -> ValueRef,
830 // Shifts may have any size int on the rhs
831 if ast_util::is_shift_binop(op.node) {
832 let mut rhs_llty = val_ty(rhs);
833 let mut lhs_llty = val_ty(lhs);
834 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
835 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
836 let rhs_sz = rhs_llty.int_width();
837 let lhs_sz = lhs_llty.int_width();
840 } else if lhs_sz > rhs_sz {
841 // FIXME (#1877: If shifting by negative
842 // values becomes not undefined then this is wrong.
852 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
853 cx: Block<'blk, 'tcx>,
859 -> Block<'blk, 'tcx> {
860 let (zero_text, overflow_text) = if divrem.node == ast::BiDiv {
861 ("attempted to divide by zero",
862 "attempted to divide with overflow")
864 ("attempted remainder with a divisor of zero",
865 "attempted remainder with overflow")
867 let (is_zero, is_signed) = match rhs_t.sty {
869 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0u64, false);
870 (ICmp(cx, llvm::IntEQ, rhs, zero), true)
873 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0u64, false);
874 (ICmp(cx, llvm::IntEQ, rhs, zero), false)
877 cx.sess().bug(&format!("fail-if-zero on unexpected type: {}",
878 ty_to_string(cx.tcx(), rhs_t))[]);
881 let bcx = with_cond(cx, is_zero, |bcx| {
882 controlflow::trans_fail(bcx, span, InternedString::new(zero_text))
885 // To quote LLVM's documentation for the sdiv instruction:
887 // Division by zero leads to undefined behavior. Overflow also leads
888 // to undefined behavior; this is a rare case, but can occur, for
889 // example, by doing a 32-bit division of -2147483648 by -1.
891 // In order to avoid undefined behavior, we perform runtime checks for
892 // signed division/remainder which would trigger overflow. For unsigned
893 // integers, no action beyond checking for zero need be taken.
895 let (llty, min) = match rhs_t.sty {
897 let llty = Type::int_from_ty(cx.ccx(), t);
899 ast::TyIs(_) if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
900 ast::TyIs(_) => i64::MIN as u64,
901 ast::TyI8 => i8::MIN as u64,
902 ast::TyI16 => i16::MIN as u64,
903 ast::TyI32 => i32::MIN as u64,
904 ast::TyI64 => i64::MIN as u64,
910 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
911 C_integral(llty, -1, false));
912 with_cond(bcx, minus_one, |bcx| {
913 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
914 C_integral(llty, min, true));
915 with_cond(bcx, is_min, |bcx| {
916 controlflow::trans_fail(bcx, span,
917 InternedString::new(overflow_text))
925 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
926 did: ast::DefId, t: Ty<'tcx>) -> ValueRef {
927 let name = csearch::get_symbol(&ccx.sess().cstore, did);
929 ty::ty_bare_fn(_, ref fn_ty) => {
930 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
932 get_extern_rust_fn(ccx, t, &name[], did)
935 ccx.sess().bug("unexpected intrinsic in trans_external_path")
938 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t,
944 get_extern_const(ccx, did, t)
949 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
954 -> (ValueRef, Block<'blk, 'tcx>) {
955 let _icx = push_ctxt("invoke_");
956 if bcx.unreachable.get() {
957 return (C_null(Type::i8(bcx.ccx())), bcx);
960 let attributes = get_fn_llvm_attributes(bcx.ccx(), fn_ty);
962 match bcx.opt_node_id {
964 debug!("invoke at ???");
967 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
971 if need_invoke(bcx) {
972 debug!("invoking {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
973 for &llarg in llargs {
974 debug!("arg: {}", bcx.val_to_string(llarg));
976 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
977 let landing_pad = bcx.fcx.get_landing_pad();
979 let llresult = Invoke(bcx,
986 return (llresult, normal_bcx);
988 debug!("calling {} at {:?}", bcx.val_to_string(llfn), bcx.llbb);
989 for &llarg in llargs {
990 debug!("arg: {}", bcx.val_to_string(llarg));
993 let llresult = Call(bcx,
998 return (llresult, bcx);
1002 pub fn need_invoke(bcx: Block) -> bool {
1003 if bcx.sess().no_landing_pads() {
1007 // Avoid using invoke if we are already inside a landing pad.
1012 bcx.fcx.needs_invoke()
1015 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1016 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
1017 let _icx = push_ctxt("load_if_immediate");
1018 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
1022 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1023 /// differs from the type used for SSA values. Also handles various special cases where the type
1024 /// gives us better information about what we are loading.
1025 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1026 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
1027 if type_is_zero_size(cx.ccx(), t) {
1028 C_undef(type_of::type_of(cx.ccx(), t))
1029 } else if ty::type_is_bool(t) {
1030 Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
1031 } else if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
1032 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1033 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1034 // and we have to convert it
1035 Load(cx, BitCast(cx, ptr, type_of::arg_type_of(cx.ccx(), t).ptr_to()))
1036 } else if ty::type_is_char(t) {
1037 // a char is a Unicode codepoint, and so takes values from 0
1038 // to 0x10FFFF inclusive only.
1039 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1045 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1046 /// differs from the type used for SSA values.
1047 pub fn store_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>, v: ValueRef, dst: ValueRef, t: Ty<'tcx>) {
1048 if ty::type_is_bool(t) {
1049 Store(cx, ZExt(cx, v, Type::i8(cx.ccx())), dst);
1050 } else if type_is_immediate(cx.ccx(), t) && type_of::type_of(cx.ccx(), t).is_aggregate() {
1051 // We want to pass small aggregates as immediate values, but using an aggregate LLVM type
1052 // for this leads to bad optimizations, so its arg type is an appropriately sized integer
1053 // and we have to convert it
1054 Store(cx, v, BitCast(cx, dst, type_of::arg_type_of(cx.ccx(), t).ptr_to()));
1060 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &ast::Local)
1061 -> Block<'blk, 'tcx> {
1062 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1063 let _indenter = indenter();
1064 let _icx = push_ctxt("init_local");
1065 _match::store_local(bcx, local)
1068 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1070 llbb: BasicBlockRef)
1071 -> Block<'blk, 'tcx> {
1072 common::BlockS::new(llbb, is_lpad, None, fcx)
1075 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
1078 -> Block<'blk, 'tcx> where
1079 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
1081 let _icx = push_ctxt("with_cond");
1083 let next_cx = fcx.new_temp_block("next");
1084 let cond_cx = fcx.new_temp_block("cond");
1085 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb, DebugLoc::None);
1086 let after_cx = f(cond_cx);
1087 if !after_cx.terminated.get() {
1088 Br(after_cx, next_cx.llbb, DebugLoc::None);
1093 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1094 if cx.sess().opts.optimize == config::No {
1098 let _icx = push_ctxt("lifetime_start");
1101 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1102 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1103 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1104 Call(cx, lifetime_start, &[llsize, ptr], None, DebugLoc::None);
1107 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1108 if cx.sess().opts.optimize == config::No {
1112 let _icx = push_ctxt("lifetime_end");
1115 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1116 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1117 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1118 Call(cx, lifetime_end, &[llsize, ptr], None, DebugLoc::None);
1121 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1122 let _icx = push_ctxt("call_memcpy");
1124 let key = match &ccx.sess().target.target.target_pointer_width[] {
1125 "32" => "llvm.memcpy.p0i8.p0i8.i32",
1126 "64" => "llvm.memcpy.p0i8.p0i8.i64",
1127 tws => panic!("Unsupported target word size for memcpy: {}", tws),
1129 let memcpy = ccx.get_intrinsic(&key);
1130 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1131 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1132 let size = IntCast(cx, n_bytes, ccx.int_type());
1133 let align = C_i32(ccx, align as i32);
1134 let volatile = C_bool(ccx, false);
1135 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None, DebugLoc::None);
1138 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1139 dst: ValueRef, src: ValueRef,
1141 let _icx = push_ctxt("memcpy_ty");
1142 let ccx = bcx.ccx();
1143 if ty::type_is_structural(t) {
1144 let llty = type_of::type_of(ccx, t);
1145 let llsz = llsize_of(ccx, llty);
1146 let llalign = type_of::align_of(ccx, t);
1147 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1149 store_ty(bcx, Load(bcx, src), dst, t);
1153 pub fn zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1154 if cx.unreachable.get() { return; }
1155 let _icx = push_ctxt("zero_mem");
1157 memzero(&B(bcx), llptr, t);
1160 // Always use this function instead of storing a zero constant to the memory
1161 // in question. If you store a zero constant, LLVM will drown in vreg
1162 // allocation for large data structures, and the generated code will be
1163 // awful. (A telltale sign of this is large quantities of
1164 // `mov [byte ptr foo],0` in the generated code.)
1165 fn memzero<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>) {
1166 let _icx = push_ctxt("memzero");
1169 let llty = type_of::type_of(ccx, ty);
1171 let intrinsic_key = match &ccx.sess().target.target.target_pointer_width[] {
1172 "32" => "llvm.memset.p0i8.i32",
1173 "64" => "llvm.memset.p0i8.i64",
1174 tws => panic!("Unsupported target word size for memset: {}", tws),
1177 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1178 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1179 let llzeroval = C_u8(ccx, 0);
1180 let size = machine::llsize_of(ccx, llty);
1181 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1182 let volatile = C_bool(ccx, false);
1183 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1186 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1187 let _icx = push_ctxt("alloc_ty");
1188 let ccx = bcx.ccx();
1189 let ty = type_of::type_of(ccx, t);
1190 assert!(!ty::type_has_params(t));
1191 let val = alloca(bcx, ty, name);
1195 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1196 let p = alloca_no_lifetime(cx, ty, name);
1197 call_lifetime_start(cx, p);
1201 pub fn alloca_no_lifetime(cx: Block, ty: Type, name: &str) -> ValueRef {
1202 let _icx = push_ctxt("alloca");
1203 if cx.unreachable.get() {
1205 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1208 debuginfo::clear_source_location(cx.fcx);
1209 Alloca(cx, ty, name)
1212 pub fn alloca_zeroed<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>,
1213 name: &str) -> ValueRef {
1214 let llty = type_of::type_of(cx.ccx(), ty);
1215 if cx.unreachable.get() {
1217 return llvm::LLVMGetUndef(llty.ptr_to().to_ref());
1220 let p = alloca_no_lifetime(cx, llty, name);
1221 let b = cx.fcx.ccx.builder();
1222 b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
1227 pub fn arrayalloca(cx: Block, ty: Type, v: ValueRef) -> ValueRef {
1228 let _icx = push_ctxt("arrayalloca");
1229 if cx.unreachable.get() {
1231 return llvm::LLVMGetUndef(ty.to_ref());
1234 debuginfo::clear_source_location(cx.fcx);
1235 let p = ArrayAlloca(cx, ty, v);
1236 call_lifetime_start(cx, p);
1240 // Creates the alloca slot which holds the pointer to the slot for the final return value
1241 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1242 output_type: Ty<'tcx>) -> ValueRef {
1243 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1245 // We create an alloca to hold a pointer of type `output_type`
1246 // which will hold the pointer to the right alloca which has the
1248 if fcx.needs_ret_allocas {
1249 // Let's create the stack slot
1250 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1252 // and if we're using an out pointer, then store that in our newly made slot
1253 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1254 let outptr = get_param(fcx.llfn, 0);
1256 let b = fcx.ccx.builder();
1257 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1258 b.store(outptr, slot);
1263 // But if there are no nested returns, we skip the indirection and have a single
1266 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1267 get_param(fcx.llfn, 0)
1269 AllocaFcx(fcx, lloutputtype, "sret_slot")
1274 struct FindNestedReturn {
1278 impl FindNestedReturn {
1279 fn new() -> FindNestedReturn {
1280 FindNestedReturn { found: false }
1284 impl<'v> Visitor<'v> for FindNestedReturn {
1285 fn visit_expr(&mut self, e: &ast::Expr) {
1287 ast::ExprRet(..) => {
1290 _ => visit::walk_expr(self, e)
1295 fn build_cfg(tcx: &ty::ctxt, id: ast::NodeId) -> (ast::NodeId, Option<cfg::CFG>) {
1296 let blk = match tcx.map.find(id) {
1297 Some(ast_map::NodeItem(i)) => {
1299 ast::ItemFn(_, _, _, _, ref blk) => {
1302 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1305 Some(ast_map::NodeTraitItem(trait_method)) => {
1306 match *trait_method {
1307 ast::ProvidedMethod(ref m) => {
1309 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1312 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1315 ast::RequiredMethod(_) => {
1316 tcx.sess.bug("unexpected variant: required trait method \
1317 in has_nested_returns")
1319 ast::TypeTraitItem(_) => {
1320 tcx.sess.bug("unexpected variant: type trait item in \
1321 has_nested_returns")
1325 Some(ast_map::NodeImplItem(ii)) => {
1327 ast::MethodImplItem(ref m) => {
1329 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1332 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1335 ast::TypeImplItem(_) => {
1336 tcx.sess.bug("unexpected variant: type impl item in \
1337 has_nested_returns")
1341 Some(ast_map::NodeExpr(e)) => {
1343 ast::ExprClosure(_, _, _, ref blk) => {
1346 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1349 Some(ast_map::NodeVariant(..)) |
1350 Some(ast_map::NodeStructCtor(..)) => return (ast::DUMMY_NODE_ID, None),
1353 None if id == ast::DUMMY_NODE_ID => return (ast::DUMMY_NODE_ID, None),
1355 _ => tcx.sess.bug(format!("unexpected variant in has_nested_returns: {}",
1356 tcx.map.path_to_string(id)).as_slice())
1359 (blk.id, Some(cfg::CFG::new(tcx, &**blk)))
1362 // Checks for the presence of "nested returns" in a function.
1363 // Nested returns are when the inner expression of a return expression
1364 // (the 'expr' in 'return expr') contains a return expression. Only cases
1365 // where the outer return is actually reachable are considered. Implicit
1366 // returns from the end of blocks are considered as well.
1368 // This check is needed to handle the case where the inner expression is
1369 // part of a larger expression that may have already partially-filled the
1370 // return slot alloca. This can cause errors related to clean-up due to
1371 // the clobbering of the existing value in the return slot.
1372 fn has_nested_returns(tcx: &ty::ctxt, cfg: &cfg::CFG, blk_id: ast::NodeId) -> bool {
1373 for n in cfg.graph.depth_traverse(cfg.entry) {
1374 match tcx.map.find(n.id) {
1375 Some(ast_map::NodeExpr(ex)) => {
1376 if let ast::ExprRet(Some(ref ret_expr)) = ex.node {
1377 let mut visitor = FindNestedReturn::new();
1378 visit::walk_expr(&mut visitor, &**ret_expr);
1384 Some(ast_map::NodeBlock(blk)) if blk.id == blk_id => {
1385 let mut visitor = FindNestedReturn::new();
1386 visit::walk_expr_opt(&mut visitor, &blk.expr);
1398 // NB: must keep 4 fns in sync:
1401 // - create_datums_for_fn_args.
1405 // Be warned! You must call `init_function` before doing anything with the
1406 // returned function context.
1407 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1411 output_type: ty::FnOutput<'tcx>,
1412 param_substs: &'a Substs<'tcx>,
1414 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1415 -> FunctionContext<'a, 'tcx> {
1416 common::validate_substs(param_substs);
1418 debug!("new_fn_ctxt(path={}, id={}, param_substs={})",
1422 ccx.tcx().map.path_to_string(id).to_string()
1424 id, param_substs.repr(ccx.tcx()));
1426 let uses_outptr = match output_type {
1427 ty::FnConverging(output_type) => {
1428 let substd_output_type =
1429 monomorphize::apply_param_substs(ccx.tcx(), param_substs, &output_type);
1430 type_of::return_uses_outptr(ccx, substd_output_type)
1432 ty::FnDiverging => false
1434 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1435 let (blk_id, cfg) = build_cfg(ccx.tcx(), id);
1436 let nested_returns = if let Some(ref cfg) = cfg {
1437 has_nested_returns(ccx.tcx(), cfg, blk_id)
1442 let mut fcx = FunctionContext {
1445 llretslotptr: Cell::new(None),
1446 param_env: ty::empty_parameter_environment(ccx.tcx()),
1447 alloca_insert_pt: Cell::new(None),
1448 llreturn: Cell::new(None),
1449 needs_ret_allocas: nested_returns,
1450 personality: Cell::new(None),
1451 caller_expects_out_pointer: uses_outptr,
1452 lllocals: RefCell::new(NodeMap()),
1453 llupvars: RefCell::new(NodeMap()),
1455 param_substs: param_substs,
1457 block_arena: block_arena,
1459 debug_context: debug_context,
1460 scopes: RefCell::new(Vec::new()),
1465 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1471 /// Performs setup on a newly created function, creating the entry scope block
1472 /// and allocating space for the return pointer.
1473 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1475 output: ty::FnOutput<'tcx>)
1476 -> Block<'a, 'tcx> {
1477 let entry_bcx = fcx.new_temp_block("entry-block");
1479 // Use a dummy instruction as the insertion point for all allocas.
1480 // This is later removed in FunctionContext::cleanup.
1481 fcx.alloca_insert_pt.set(Some(unsafe {
1482 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1483 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1486 if let ty::FnConverging(output_type) = output {
1487 // This shouldn't need to recompute the return type,
1488 // as new_fn_ctxt did it already.
1489 let substd_output_type = fcx.monomorphize(&output_type);
1490 if !return_type_is_void(fcx.ccx, substd_output_type) {
1491 // If the function returns nil/bot, there is no real return
1492 // value, so do not set `llretslotptr`.
1493 if !skip_retptr || fcx.caller_expects_out_pointer {
1494 // Otherwise, we normally allocate the llretslotptr, unless we
1495 // have been instructed to skip it for immediate return
1497 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1505 // NB: must keep 4 fns in sync:
1508 // - create_datums_for_fn_args.
1512 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1514 use trans::datum::{ByRef, ByValue};
1517 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1521 // work around bizarre resolve errors
1522 type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>;
1524 // create_datums_for_fn_args: creates rvalue datums for each of the
1525 // incoming function arguments. These will later be stored into
1526 // appropriate lvalue datums.
1527 pub fn create_datums_for_fn_args<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1528 arg_tys: &[Ty<'tcx>])
1529 -> Vec<RvalueDatum<'tcx>> {
1530 let _icx = push_ctxt("create_datums_for_fn_args");
1532 // Return an array wrapping the ValueRefs that we get from `get_param` for
1533 // each argument into datums.
1534 arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
1535 let llarg = get_param(fcx.llfn, fcx.arg_pos(i) as c_uint);
1536 datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty))
1540 /// Creates rvalue datums for each of the incoming function arguments and
1541 /// tuples the arguments. These will later be stored into appropriate lvalue
1544 /// FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1545 fn create_datums_for_fn_args_under_call_abi<'blk, 'tcx>(
1546 mut bcx: Block<'blk, 'tcx>,
1547 arg_scope: cleanup::CustomScopeIndex,
1548 arg_tys: &[Ty<'tcx>])
1549 -> Vec<RvalueDatum<'tcx>> {
1550 let mut result = Vec::new();
1551 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1552 if i < arg_tys.len() - 1 {
1553 // Regular argument.
1554 let llarg = get_param(bcx.fcx.llfn, bcx.fcx.arg_pos(i) as c_uint);
1555 result.push(datum::Datum::new(llarg, arg_ty, arg_kind(bcx.fcx,
1560 // This is the last argument. Tuple it.
1562 ty::ty_tup(ref tupled_arg_tys) => {
1563 let tuple_args_scope_id = cleanup::CustomScope(arg_scope);
1566 datum::lvalue_scratch_datum(bcx,
1570 tuple_args_scope_id,
1575 for (j, &tupled_arg_ty) in
1576 tupled_arg_tys.iter().enumerate() {
1578 get_param(bcx.fcx.llfn,
1579 bcx.fcx.arg_pos(i + j) as c_uint);
1580 let lldest = GEPi(bcx, llval, &[0, j]);
1581 let datum = datum::Datum::new(
1584 arg_kind(bcx.fcx, tupled_arg_ty));
1585 bcx = datum.store_to(bcx, lldest);
1589 let tuple = unpack_datum!(bcx,
1590 tuple.to_expr_datum()
1591 .to_rvalue_datum(bcx,
1596 bcx.tcx().sess.bug("last argument of a function with \
1597 `rust-call` ABI isn't a tuple?!")
1606 fn copy_args_to_allocas<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1607 arg_scope: cleanup::CustomScopeIndex,
1609 arg_datums: Vec<RvalueDatum<'tcx>>)
1610 -> Block<'blk, 'tcx> {
1611 debug!("copy_args_to_allocas");
1613 let _icx = push_ctxt("copy_args_to_allocas");
1616 let arg_scope_id = cleanup::CustomScope(arg_scope);
1618 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
1619 // For certain mode/type combinations, the raw llarg values are passed
1620 // by value. However, within the fn body itself, we want to always
1621 // have all locals and arguments be by-ref so that we can cancel the
1622 // cleanup and for better interaction with LLVM's debug info. So, if
1623 // the argument would be passed by value, we store it into an alloca.
1624 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1625 // the event it's not truly needed.
1627 bcx = _match::store_arg(bcx, &*args[i].pat, arg_datum, arg_scope_id);
1628 debuginfo::create_argument_metadata(bcx, &args[i]);
1634 fn copy_closure_args_to_allocas<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1635 arg_scope: cleanup::CustomScopeIndex,
1637 arg_datums: Vec<RvalueDatum<'tcx>>,
1638 monomorphized_arg_types: &[Ty<'tcx>])
1639 -> Block<'blk, 'tcx> {
1640 let _icx = push_ctxt("copy_closure_args_to_allocas");
1641 let arg_scope_id = cleanup::CustomScope(arg_scope);
1643 assert_eq!(arg_datums.len(), 1);
1645 let arg_datum = arg_datums.into_iter().next().unwrap();
1647 // Untuple the rest of the arguments.
1650 arg_datum.to_lvalue_datum_in_scope(bcx,
1653 let untupled_arg_types = match monomorphized_arg_types[0].sty {
1654 ty::ty_tup(ref types) => &types[],
1656 bcx.tcx().sess.span_bug(args[0].pat.span,
1657 "first arg to `rust-call` ABI function \
1661 for j in 0..args.len() {
1662 let tuple_element_type = untupled_arg_types[j];
1663 let tuple_element_datum =
1664 tuple_datum.get_element(bcx,
1666 |llval| GEPi(bcx, llval, &[0, j]));
1667 let tuple_element_datum = tuple_element_datum.to_expr_datum();
1668 let tuple_element_datum =
1670 tuple_element_datum.to_rvalue_datum(bcx,
1672 bcx = _match::store_arg(bcx,
1674 tuple_element_datum,
1677 debuginfo::create_argument_metadata(bcx, &args[j]);
1683 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1684 // and builds the return block.
1685 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1686 last_bcx: Block<'blk, 'tcx>,
1687 retty: ty::FnOutput<'tcx>,
1688 ret_debug_loc: DebugLoc) {
1689 let _icx = push_ctxt("finish_fn");
1691 let ret_cx = match fcx.llreturn.get() {
1693 if !last_bcx.terminated.get() {
1694 Br(last_bcx, llreturn, DebugLoc::None);
1696 raw_block(fcx, false, llreturn)
1701 // This shouldn't need to recompute the return type,
1702 // as new_fn_ctxt did it already.
1703 let substd_retty = fcx.monomorphize(&retty);
1704 build_return_block(fcx, ret_cx, substd_retty, ret_debug_loc);
1706 debuginfo::clear_source_location(fcx);
1710 // Builds the return block for a function.
1711 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1712 ret_cx: Block<'blk, 'tcx>,
1713 retty: ty::FnOutput<'tcx>,
1714 ret_debug_location: DebugLoc) {
1715 if fcx.llretslotptr.get().is_none() ||
1716 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1717 return RetVoid(ret_cx, ret_debug_location);
1720 let retslot = if fcx.needs_ret_allocas {
1721 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1723 fcx.llretslotptr.get().unwrap()
1725 let retptr = Value(retslot);
1726 match retptr.get_dominating_store(ret_cx) {
1727 // If there's only a single store to the ret slot, we can directly return
1728 // the value that was stored and omit the store and the alloca
1730 let retval = s.get_operand(0).unwrap().get();
1731 s.erase_from_parent();
1733 if retptr.has_no_uses() {
1734 retptr.erase_from_parent();
1737 let retval = if retty == ty::FnConverging(fcx.ccx.tcx().types.bool) {
1738 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1743 if fcx.caller_expects_out_pointer {
1744 if let ty::FnConverging(retty) = retty {
1745 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1747 RetVoid(ret_cx, ret_debug_location)
1749 Ret(ret_cx, retval, ret_debug_location)
1752 // Otherwise, copy the return value to the ret slot
1753 None => match retty {
1754 ty::FnConverging(retty) => {
1755 if fcx.caller_expects_out_pointer {
1756 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1757 RetVoid(ret_cx, ret_debug_location)
1759 Ret(ret_cx, load_ty(ret_cx, retslot, retty), ret_debug_location)
1762 ty::FnDiverging => {
1763 if fcx.caller_expects_out_pointer {
1764 RetVoid(ret_cx, ret_debug_location)
1766 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)), ret_debug_location)
1773 // trans_closure: Builds an LLVM function out of a source function.
1774 // If the function closes over its environment a closure will be
1776 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1780 param_substs: &Substs<'tcx>,
1781 fn_ast_id: ast::NodeId,
1782 _attributes: &[ast::Attribute],
1783 output_type: ty::FnOutput<'tcx>,
1785 closure_env: closure::ClosureEnv<'b>) {
1786 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1788 let _icx = push_ctxt("trans_closure");
1789 set_uwtable(llfndecl);
1791 debug!("trans_closure(..., param_substs={})",
1792 param_substs.repr(ccx.tcx()));
1794 let has_env = match closure_env {
1795 closure::ClosureEnv::Closure(_) => true,
1796 closure::ClosureEnv::NotClosure => false,
1799 let (arena, fcx): (TypedArena<_>, FunctionContext);
1800 arena = TypedArena::new();
1801 fcx = new_fn_ctxt(ccx,
1809 let mut bcx = init_function(&fcx, false, output_type);
1811 // cleanup scope for the incoming arguments
1812 let fn_cleanup_debug_loc =
1813 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1814 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1816 let block_ty = node_id_type(bcx, body.id);
1818 // Set up arguments to the function.
1819 let monomorphized_arg_types =
1821 .map(|arg| node_id_type(bcx, arg.id))
1822 .collect::<Vec<_>>();
1823 let monomorphized_arg_types = match closure_env {
1824 closure::ClosureEnv::NotClosure => {
1825 monomorphized_arg_types
1828 // Tuple up closure argument types for the "rust-call" ABI.
1829 closure::ClosureEnv::Closure(_) => {
1830 vec![ty::mk_tup(ccx.tcx(), monomorphized_arg_types)]
1833 for monomorphized_arg_type in &monomorphized_arg_types {
1834 debug!("trans_closure: monomorphized_arg_type: {}",
1835 ty_to_string(ccx.tcx(), *monomorphized_arg_type));
1837 debug!("trans_closure: function lltype: {}",
1838 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1840 let arg_datums = if abi != RustCall {
1841 create_datums_for_fn_args(&fcx,
1842 &monomorphized_arg_types[])
1844 create_datums_for_fn_args_under_call_abi(
1847 &monomorphized_arg_types[])
1850 bcx = match closure_env {
1851 closure::ClosureEnv::NotClosure => {
1852 copy_args_to_allocas(bcx,
1857 closure::ClosureEnv::Closure(_) => {
1858 copy_closure_args_to_allocas(
1863 &monomorphized_arg_types[])
1867 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1869 // Up until here, IR instructions for this function have explicitly not been annotated with
1870 // source code location, so we don't step into call setup code. From here on, source location
1871 // emitting should be enabled.
1872 debuginfo::start_emitting_source_locations(&fcx);
1874 let dest = match fcx.llretslotptr.get() {
1875 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1877 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1882 // This call to trans_block is the place where we bridge between
1883 // translation calls that don't have a return value (trans_crate,
1884 // trans_mod, trans_item, et cetera) and those that do
1885 // (trans_block, trans_expr, et cetera).
1886 bcx = controlflow::trans_block(bcx, body, dest);
1889 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1890 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1895 match fcx.llreturn.get() {
1897 Br(bcx, fcx.return_exit_block(), DebugLoc::None);
1898 fcx.pop_custom_cleanup_scope(arg_scope);
1901 // Microoptimization writ large: avoid creating a separate
1902 // llreturn basic block
1903 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1907 // Put return block after all other blocks.
1908 // This somewhat improves single-stepping experience in debugger.
1910 let llreturn = fcx.llreturn.get();
1911 if let Some(llreturn) = llreturn {
1912 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1916 let ret_debug_loc = DebugLoc::At(fn_cleanup_debug_loc.id,
1917 fn_cleanup_debug_loc.span);
1919 // Insert the mandatory first few basic blocks before lltop.
1920 finish_fn(&fcx, bcx, output_type, ret_debug_loc);
1923 // trans_fn: creates an LLVM function corresponding to a source language
1925 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1929 param_substs: &Substs<'tcx>,
1931 attrs: &[ast::Attribute]) {
1932 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1933 debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx()));
1934 let _icx = push_ctxt("trans_fn");
1935 let fn_ty = ty::node_id_to_type(ccx.tcx(), id);
1936 let output_type = ty::erase_late_bound_regions(ccx.tcx(), &ty::ty_fn_ret(fn_ty));
1937 let abi = ty::ty_fn_abi(fn_ty);
1947 closure::ClosureEnv::NotClosure);
1950 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1951 _enum_id: ast::NodeId,
1952 variant: &ast::Variant,
1953 _args: &[ast::VariantArg],
1955 param_substs: &Substs<'tcx>,
1956 llfndecl: ValueRef) {
1957 let _icx = push_ctxt("trans_enum_variant");
1959 trans_enum_variant_or_tuple_like_struct(
1967 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1970 args: callee::CallArgs,
1972 debug_loc: DebugLoc)
1973 -> Result<'blk, 'tcx> {
1975 let ccx = bcx.fcx.ccx;
1976 let tcx = ccx.tcx();
1978 let result_ty = match ctor_ty.sty {
1979 ty::ty_bare_fn(_, ref bft) => {
1980 ty::erase_late_bound_regions(bcx.tcx(), &bft.sig.output()).unwrap()
1982 _ => ccx.sess().bug(
1983 &format!("trans_enum_variant_constructor: \
1984 unexpected ctor return type {}",
1985 ctor_ty.repr(tcx))[])
1988 // Get location to store the result. If the user does not care about
1989 // the result, just make a stack slot
1990 let llresult = match dest {
1991 expr::SaveIn(d) => d,
1993 if !type_is_zero_size(ccx, result_ty) {
1994 alloc_ty(bcx, result_ty, "constructor_result")
1996 C_undef(type_of::type_of(ccx, result_ty))
2001 if !type_is_zero_size(ccx, result_ty) {
2003 callee::ArgExprs(exprs) => {
2004 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2005 bcx = expr::trans_adt(bcx,
2010 expr::SaveIn(llresult),
2013 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
2017 // If the caller doesn't care about the result
2018 // drop the temporary we made
2019 let bcx = match dest {
2020 expr::SaveIn(_) => bcx,
2022 glue::drop_ty(bcx, llresult, result_ty, debug_loc)
2026 Result::new(bcx, llresult)
2029 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2030 _fields: &[ast::StructField],
2031 ctor_id: ast::NodeId,
2032 param_substs: &Substs<'tcx>,
2033 llfndecl: ValueRef) {
2034 let _icx = push_ctxt("trans_tuple_struct");
2036 trans_enum_variant_or_tuple_like_struct(
2044 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2045 ctor_id: ast::NodeId,
2047 param_substs: &Substs<'tcx>,
2048 llfndecl: ValueRef) {
2049 let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2050 let ctor_ty = monomorphize::apply_param_substs(ccx.tcx(), param_substs, &ctor_ty);
2052 let result_ty = match ctor_ty.sty {
2053 ty::ty_bare_fn(_, ref bft) => {
2054 ty::erase_late_bound_regions(ccx.tcx(), &bft.sig.output())
2056 _ => ccx.sess().bug(
2057 &format!("trans_enum_variant_or_tuple_like_struct: \
2058 unexpected ctor return type {}",
2059 ty_to_string(ccx.tcx(), ctor_ty))[])
2062 let (arena, fcx): (TypedArena<_>, FunctionContext);
2063 arena = TypedArena::new();
2064 fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
2065 param_substs, None, &arena);
2066 let bcx = init_function(&fcx, false, result_ty);
2068 assert!(!fcx.needs_ret_allocas);
2071 ty::erase_late_bound_regions(
2072 ccx.tcx(), &ty::ty_fn_args(ctor_ty));
2074 let arg_datums = create_datums_for_fn_args(&fcx, &arg_tys[]);
2076 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2077 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2078 let repr = adt::represent_type(ccx, result_ty.unwrap());
2079 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
2080 let lldestptr = adt::trans_field_ptr(bcx,
2085 arg_datum.store_to(bcx, lldestptr);
2087 adt::trans_set_discr(bcx, &*repr, dest, disr);
2090 finish_fn(&fcx, bcx, result_ty, DebugLoc::None);
2093 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
2094 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2096 let print_info = ccx.sess().print_enum_sizes();
2098 let levels = ccx.tcx().node_lint_levels.borrow();
2099 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2100 let lvlsrc = levels.get(&(id, lint_id));
2101 let is_allow = lvlsrc.map_or(true, |&(lvl, _)| lvl == lint::Allow);
2103 if is_allow && !print_info {
2104 // we're not interested in anything here
2108 let ty = ty::node_id_to_type(ccx.tcx(), id);
2109 let avar = adt::represent_type(ccx, ty);
2111 adt::General(_, ref variants, _) => {
2112 for var in variants {
2114 for field in var.fields.iter().skip(1) {
2115 // skip the discriminant
2116 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2121 _ => { /* its size is either constant or unimportant */ }
2124 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2125 |(l, s, li), (idx, &size)|
2128 } else if size > s {
2136 let llty = type_of::sizing_type_of(ccx, ty);
2138 let sess = &ccx.tcx().sess;
2139 sess.span_note(sp, &*format!("total size: {} bytes", llsize_of_real(ccx, llty)));
2141 adt::General(..) => {
2142 for (i, var) in enum_def.variants.iter().enumerate() {
2143 ccx.tcx().sess.span_note(var.span,
2144 &*format!("variant data: {} bytes", sizes[i]));
2151 // we only warn if the largest variant is at least thrice as large as
2152 // the second-largest.
2153 if !is_allow && largest > slargest * 3 && slargest > 0 {
2154 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2155 // pass for the latter already ran.
2156 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
2157 *lvlsrc.unwrap(), Some(sp),
2158 &format!("enum variant is more than three times larger \
2159 ({} bytes) than the next largest (ignoring padding)",
2162 ccx.sess().span_note(enum_def.variants[largest_index].span,
2163 "this variant is the largest");
2167 pub struct TransItemVisitor<'a, 'tcx: 'a> {
2168 pub ccx: &'a CrateContext<'a, 'tcx>,
2171 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemVisitor<'a, 'tcx> {
2172 fn visit_item(&mut self, i: &ast::Item) {
2173 trans_item(self.ccx, i);
2177 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2178 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2179 // applicable to variable declarations and may not really make sense for
2180 // Rust code in the first place but whitelist them anyway and trust that
2181 // the user knows what s/he's doing. Who knows, unanticipated use cases
2182 // may pop up in the future.
2184 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2185 // and don't have to be, LLVM treats them as no-ops.
2187 "appending" => Some(llvm::AppendingLinkage),
2188 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2189 "common" => Some(llvm::CommonLinkage),
2190 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2191 "external" => Some(llvm::ExternalLinkage),
2192 "internal" => Some(llvm::InternalLinkage),
2193 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2194 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2195 "private" => Some(llvm::PrivateLinkage),
2196 "weak" => Some(llvm::WeakAnyLinkage),
2197 "weak_odr" => Some(llvm::WeakODRLinkage),
2203 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2205 pub enum ValueOrigin {
2206 /// The LLVM `Value` is in this context because the corresponding item was
2207 /// assigned to the current compilation unit.
2208 OriginalTranslation,
2209 /// The `Value`'s corresponding item was assigned to some other compilation
2210 /// unit, but the `Value` was translated in this context anyway because the
2211 /// item is marked `#[inline]`.
2215 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2216 /// If the `llval` is the direct translation of a specific Rust item, `id`
2217 /// should be set to the `NodeId` of that item. (This mapping should be
2218 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2219 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2220 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2221 /// assigned to a different compilation unit.
2222 pub fn update_linkage(ccx: &CrateContext,
2224 id: Option<ast::NodeId>,
2225 llval_origin: ValueOrigin) {
2226 match llval_origin {
2228 // `llval` is a translation of an item defined in a separate
2229 // compilation unit. This only makes sense if there are at least
2230 // two compilation units.
2231 assert!(ccx.sess().opts.cg.codegen_units > 1);
2232 // `llval` is a copy of something defined elsewhere, so use
2233 // `AvailableExternallyLinkage` to avoid duplicating code in the
2235 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2238 OriginalTranslation => {},
2241 if let Some(id) = id {
2242 let item = ccx.tcx().map.get(id);
2243 if let ast_map::NodeItem(i) = item {
2244 if let Some(name) = attr::first_attr_value_str_by_name(i.attrs.as_slice(), "linkage") {
2245 if let Some(linkage) = llvm_linkage_by_name(name.get()) {
2246 llvm::SetLinkage(llval, linkage);
2248 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2256 Some(id) if ccx.reachable().contains(&id) => {
2257 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2260 // `id` does not refer to an item in `ccx.reachable`.
2261 if ccx.sess().opts.cg.codegen_units > 1 {
2262 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2264 llvm::SetLinkage(llval, llvm::InternalLinkage);
2270 pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
2271 let _icx = push_ctxt("trans_item");
2273 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2276 ast::ItemFn(ref decl, _fn_style, abi, ref generics, ref body) => {
2277 if !generics.is_type_parameterized() {
2278 let trans_everywhere = attr::requests_inline(&item.attrs[]);
2279 // Ignore `trans_everywhere` for cross-crate inlined items
2280 // (`from_external`). `trans_item` will be called once for each
2281 // compilation unit that references the item, so it will still get
2282 // translated everywhere it's needed.
2283 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2284 let llfn = get_item_val(ccx, item.id);
2286 foreign::trans_rust_fn_with_foreign_abi(ccx,
2291 &Substs::trans_empty(),
2299 &Substs::trans_empty(),
2306 if is_origin { OriginalTranslation } else { InlinedCopy });
2310 // Be sure to travel more than just one layer deep to catch nested
2311 // items in blocks and such.
2312 let mut v = TransItemVisitor{ ccx: ccx };
2313 v.visit_block(&**body);
2315 ast::ItemImpl(_, _, ref generics, _, _, ref impl_items) => {
2316 meth::trans_impl(ccx,
2322 ast::ItemMod(ref m) => {
2323 trans_mod(&ccx.rotate(), m);
2325 ast::ItemEnum(ref enum_definition, ref gens) => {
2326 if gens.ty_params.is_empty() {
2327 // sizes only make sense for non-generic types
2329 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2332 ast::ItemConst(_, ref expr) => {
2333 // Recurse on the expression to catch items in blocks
2334 let mut v = TransItemVisitor{ ccx: ccx };
2335 v.visit_expr(&**expr);
2337 ast::ItemStatic(_, m, 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 consts::trans_static(ccx, m, item.id);
2343 let g = get_item_val(ccx, item.id);
2344 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2346 // Do static_assert checking. It can't really be done much earlier
2347 // because we need to get the value of the bool out of LLVM
2348 if attr::contains_name(&item.attrs[], "static_assert") {
2349 if m == ast::MutMutable {
2350 ccx.sess().span_fatal(expr.span,
2351 "cannot have static_assert on a mutable \
2355 let v = ccx.static_values().borrow()[item.id].clone();
2357 if !(llvm::LLVMConstIntGetZExtValue(v) != 0) {
2358 ccx.sess().span_fatal(expr.span, "static assertion failed");
2363 ast::ItemForeignMod(ref foreign_mod) => {
2364 foreign::trans_foreign_mod(ccx, foreign_mod);
2366 ast::ItemTrait(..) => {
2367 // Inside of this trait definition, we won't be actually translating any
2368 // functions, but the trait still needs to be walked. Otherwise default
2369 // methods with items will not get translated and will cause ICE's when
2370 // metadata time comes around.
2371 let mut v = TransItemVisitor{ ccx: ccx };
2372 visit::walk_item(&mut v, item);
2374 _ => {/* fall through */ }
2378 // Translate a module. Doing this amounts to translating the items in the
2379 // module; there ends up being no artifact (aside from linkage names) of
2380 // separate modules in the compiled program. That's because modules exist
2381 // only as a convenience for humans working with the code, to organize names
2382 // and control visibility.
2383 pub fn trans_mod(ccx: &CrateContext, m: &ast::Mod) {
2384 let _icx = push_ctxt("trans_mod");
2385 for item in &m.items {
2386 trans_item(ccx, &**item);
2390 fn finish_register_fn(ccx: &CrateContext, sp: Span, sym: String, node_id: ast::NodeId,
2392 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2394 // The stack exhaustion lang item shouldn't have a split stack because
2395 // otherwise it would continue to be exhausted (bad), and both it and the
2396 // eh_personality functions need to be externally linkable.
2397 let def = ast_util::local_def(node_id);
2398 if ccx.tcx().lang_items.stack_exhausted() == Some(def) {
2399 unset_split_stack(llfn);
2400 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2402 if ccx.tcx().lang_items.eh_personality() == Some(def) {
2403 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2407 if is_entry_fn(ccx.sess(), node_id) {
2408 create_entry_wrapper(ccx, sp, llfn);
2412 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2415 node_id: ast::NodeId,
2416 node_type: Ty<'tcx>)
2418 match node_type.sty {
2419 ty::ty_bare_fn(_, ref f) => {
2420 assert!(f.abi == Rust || f.abi == RustCall);
2422 _ => panic!("expected bare rust fn")
2425 let llfn = decl_rust_fn(ccx, node_type, &sym[]);
2426 finish_register_fn(ccx, sp, sym, node_id, llfn);
2430 pub fn get_fn_llvm_attributes<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>)
2431 -> llvm::AttrBuilder
2433 use middle::ty::{BrAnon, ReLateBound};
2436 let (fn_sig, abi, has_env) = match fn_ty.sty {
2437 ty::ty_bare_fn(_, ref f) => (&f.sig, f.abi, false),
2438 ty::ty_closure(closure_did, _, substs) => {
2439 let typer = common::NormalizingClosureTyper::new(ccx.tcx());
2440 function_type = typer.closure_type(closure_did, substs);
2441 (&function_type.sig, RustCall, true)
2443 _ => ccx.sess().bug("expected closure or function.")
2446 let fn_sig = ty::erase_late_bound_regions(ccx.tcx(), fn_sig);
2448 // Since index 0 is the return value of the llvm func, we start
2449 // at either 1 or 2 depending on whether there's an env slot or not
2450 let mut first_arg_offset = if has_env { 2 } else { 1 };
2451 let mut attrs = llvm::AttrBuilder::new();
2452 let ret_ty = fn_sig.output;
2454 // These have an odd calling convention, so we need to manually
2455 // unpack the input ty's
2456 let input_tys = match fn_ty.sty {
2457 ty::ty_closure(_, _, _) => {
2458 assert!(abi == RustCall);
2460 match fn_sig.inputs[0].sty {
2461 ty::ty_tup(ref inputs) => inputs.clone(),
2462 _ => ccx.sess().bug("expected tuple'd inputs")
2465 ty::ty_bare_fn(..) if abi == RustCall => {
2466 let mut inputs = vec![fn_sig.inputs[0]];
2468 match fn_sig.inputs[1].sty {
2469 ty::ty_tup(ref t_in) => {
2470 inputs.push_all(&t_in[]);
2473 _ => ccx.sess().bug("expected tuple'd inputs")
2476 _ => fn_sig.inputs.clone()
2479 if let ty::FnConverging(ret_ty) = ret_ty {
2480 // A function pointer is called without the declaration
2481 // available, so we have to apply any attributes with ABI
2482 // implications directly to the call instruction. Right now,
2483 // the only attribute we need to worry about is `sret`.
2484 if type_of::return_uses_outptr(ccx, ret_ty) {
2485 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, ret_ty));
2487 // The outptr can be noalias and nocapture because it's entirely
2488 // invisible to the program. We also know it's nonnull as well
2489 // as how many bytes we can dereference
2490 attrs.arg(1, llvm::StructRetAttribute)
2491 .arg(1, llvm::NoAliasAttribute)
2492 .arg(1, llvm::NoCaptureAttribute)
2493 .arg(1, llvm::DereferenceableAttribute(llret_sz));
2495 // Add one more since there's an outptr
2496 first_arg_offset += 1;
2498 // The `noalias` attribute on the return value is useful to a
2499 // function ptr caller.
2501 // `~` pointer return values never alias because ownership
2503 ty::ty_uniq(it) if !common::type_is_sized(ccx.tcx(), it) => {}
2505 attrs.ret(llvm::NoAliasAttribute);
2510 // We can also mark the return value as `dereferenceable` in certain cases
2512 // These are not really pointers but pairs, (pointer, len)
2514 ty::ty_rptr(_, ty::mt { ty: it, .. }) if !common::type_is_sized(ccx.tcx(), it) => {}
2515 ty::ty_uniq(inner) | ty::ty_rptr(_, ty::mt { ty: inner, .. }) => {
2516 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2517 attrs.ret(llvm::DereferenceableAttribute(llret_sz));
2522 if let ty::ty_bool = ret_ty.sty {
2523 attrs.ret(llvm::ZExtAttribute);
2528 for (idx, &t) in input_tys.iter().enumerate().map(|(i, v)| (i + first_arg_offset, v)) {
2530 // this needs to be first to prevent fat pointers from falling through
2531 _ if !type_is_immediate(ccx, t) => {
2532 let llarg_sz = llsize_of_real(ccx, type_of::type_of(ccx, t));
2534 // For non-immediate arguments the callee gets its own copy of
2535 // the value on the stack, so there are no aliases. It's also
2536 // program-invisible so can't possibly capture
2537 attrs.arg(idx, llvm::NoAliasAttribute)
2538 .arg(idx, llvm::NoCaptureAttribute)
2539 .arg(idx, llvm::DereferenceableAttribute(llarg_sz));
2543 attrs.arg(idx, llvm::ZExtAttribute);
2546 // `~` pointer parameters never alias because ownership is transferred
2547 ty::ty_uniq(inner) => {
2548 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2550 attrs.arg(idx, llvm::NoAliasAttribute)
2551 .arg(idx, llvm::DereferenceableAttribute(llsz));
2554 // `&mut` pointer parameters never alias other parameters, or mutable global data
2556 // `&T` where `T` contains no `UnsafeCell<U>` is immutable, and can be marked as both
2557 // `readonly` and `noalias`, as LLVM's definition of `noalias` is based solely on
2558 // memory dependencies rather than pointer equality
2559 ty::ty_rptr(b, mt) if mt.mutbl == ast::MutMutable ||
2560 !ty::type_contents(ccx.tcx(), mt.ty).interior_unsafe() => {
2562 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2563 attrs.arg(idx, llvm::NoAliasAttribute)
2564 .arg(idx, llvm::DereferenceableAttribute(llsz));
2566 if mt.mutbl == ast::MutImmutable {
2567 attrs.arg(idx, llvm::ReadOnlyAttribute);
2570 if let ReLateBound(_, BrAnon(_)) = *b {
2571 attrs.arg(idx, llvm::NoCaptureAttribute);
2575 // When a reference in an argument has no named lifetime, it's impossible for that
2576 // reference to escape this function (returned or stored beyond the call by a closure).
2577 ty::ty_rptr(&ReLateBound(_, BrAnon(_)), mt) => {
2578 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2579 attrs.arg(idx, llvm::NoCaptureAttribute)
2580 .arg(idx, llvm::DereferenceableAttribute(llsz));
2583 // & pointer parameters are also never null and we know exactly how
2584 // many bytes we can dereference
2585 ty::ty_rptr(_, mt) => {
2586 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2587 attrs.arg(idx, llvm::DereferenceableAttribute(llsz));
2596 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2597 pub fn register_fn_llvmty(ccx: &CrateContext,
2600 node_id: ast::NodeId,
2602 llfty: Type) -> ValueRef {
2603 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2605 let llfn = decl_fn(ccx,
2609 ty::FnConverging(ty::mk_nil(ccx.tcx())));
2610 finish_register_fn(ccx, sp, sym, node_id, llfn);
2614 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2615 match *sess.entry_fn.borrow() {
2616 Some((entry_id, _)) => node_id == entry_id,
2621 // Create a _rust_main(args: ~[str]) function which will be called from the
2622 // runtime rust_start function
2623 pub fn create_entry_wrapper(ccx: &CrateContext,
2625 main_llfn: ValueRef) {
2626 let et = ccx.sess().entry_type.get().unwrap();
2628 config::EntryMain => {
2629 create_entry_fn(ccx, main_llfn, true);
2631 config::EntryStart => create_entry_fn(ccx, main_llfn, false),
2632 config::EntryNone => {} // Do nothing.
2635 fn create_entry_fn(ccx: &CrateContext,
2636 rust_main: ValueRef,
2637 use_start_lang_item: bool) {
2638 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2641 let llfn = decl_cdecl_fn(ccx, "main", llfty, ty::mk_nil(ccx.tcx()));
2643 // FIXME: #16581: Marking a symbol in the executable with `dllexport`
2644 // linkage forces MinGW's linker to output a `.reloc` section for ASLR
2645 if ccx.sess().target.target.options.is_like_windows {
2646 unsafe { llvm::LLVMRustSetDLLExportStorageClass(llfn) }
2650 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn,
2651 "top\0".as_ptr() as *const _)
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 = llvm::LLVMBuildPointerCast(bld,
2674 rust_main, Type::i8p(ccx).to_ref(),
2675 "rust_main\0".as_ptr() as *const _);
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 buf = CString::from_slice(sym.as_bytes());
2783 let g = llvm::LLVMAddGlobal(ccx.llmod(), llty,
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 let buf = CString::from_slice(sect.get().as_bytes());
2827 llvm::LLVMSetSection(v, buf.as_ptr());
2836 ast_map::NodeTraitItem(trait_method) => {
2837 debug!("get_item_val(): processing a NodeTraitItem");
2838 match *trait_method {
2839 ast::RequiredMethod(_) | ast::TypeTraitItem(_) => {
2840 ccx.sess().bug("unexpected variant: required trait \
2841 method in get_item_val()");
2843 ast::ProvidedMethod(ref m) => {
2844 register_method(ccx, id, &**m)
2849 ast_map::NodeImplItem(ii) => {
2851 ast::MethodImplItem(ref m) => register_method(ccx, id, &**m),
2852 ast::TypeImplItem(ref typedef) => {
2853 ccx.sess().span_bug(typedef.span,
2854 "unexpected variant: required impl \
2855 method in get_item_val()")
2860 ast_map::NodeForeignItem(ni) => {
2862 ast::ForeignItemFn(..) => {
2863 let abi = ccx.tcx().map.get_foreign_abi(id);
2864 let ty = ty::node_id_to_type(ccx.tcx(), ni.id);
2865 let name = foreign::link_name(&*ni);
2866 foreign::register_foreign_item_fn(ccx, abi, ty, &name.get()[])
2868 ast::ForeignItemStatic(..) => {
2869 foreign::register_static(ccx, &*ni)
2874 ast_map::NodeVariant(ref v) => {
2876 let args = match v.node.kind {
2877 ast::TupleVariantKind(ref args) => args,
2878 ast::StructVariantKind(_) => {
2879 panic!("struct variant kind unexpected in get_item_val")
2882 assert!(args.len() != 0);
2883 let ty = ty::node_id_to_type(ccx.tcx(), id);
2884 let parent = ccx.tcx().map.get_parent(id);
2885 let enm = ccx.tcx().map.expect_item(parent);
2886 let sym = exported_name(ccx,
2891 llfn = match enm.node {
2892 ast::ItemEnum(_, _) => {
2893 register_fn(ccx, (*v).span, sym, id, ty)
2895 _ => panic!("NodeVariant, shouldn't happen")
2897 set_inline_hint(llfn);
2901 ast_map::NodeStructCtor(struct_def) => {
2902 // Only register the constructor if this is a tuple-like struct.
2903 let ctor_id = match struct_def.ctor_id {
2905 ccx.sess().bug("attempt to register a constructor of \
2906 a non-tuple-like struct")
2908 Some(ctor_id) => ctor_id,
2910 let parent = ccx.tcx().map.get_parent(id);
2911 let struct_item = ccx.tcx().map.expect_item(parent);
2912 let ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2913 let sym = exported_name(ccx,
2916 &struct_item.attrs[]);
2917 let llfn = register_fn(ccx, struct_item.span,
2919 set_inline_hint(llfn);
2924 ccx.sess().bug(&format!("get_item_val(): unexpected variant: {:?}",
2929 // All LLVM globals and functions are initially created as external-linkage
2930 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2931 // into a definition, it adjusts the linkage then (using `update_linkage`).
2933 // The exception is foreign items, which have their linkage set inside the
2934 // call to `foreign::register_*` above. We don't touch the linkage after
2935 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2936 // other item translation functions do).
2938 ccx.item_vals().borrow_mut().insert(id, val);
2942 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2943 m: &ast::Method) -> ValueRef {
2944 let mty = ty::node_id_to_type(ccx.tcx(), id);
2946 let sym = exported_name(ccx, id, mty, &m.attrs[]);
2948 let llfn = register_fn(ccx, m.span, sym, id, mty);
2949 set_llvm_fn_attrs(ccx, &m.attrs[], llfn);
2953 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'tcx>,
2954 ie: encoder::EncodeInlinedItem<'a>)
2955 -> encoder::EncodeParams<'a, 'tcx> {
2956 encoder::EncodeParams {
2957 diag: cx.sess().diagnostic(),
2959 reexports: cx.export_map(),
2960 item_symbols: cx.item_symbols(),
2961 link_meta: cx.link_meta(),
2962 cstore: &cx.sess().cstore,
2963 encode_inlined_item: ie,
2964 reachable: cx.reachable(),
2968 pub fn write_metadata(cx: &SharedCrateContext, krate: &ast::Crate) -> Vec<u8> {
2971 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2972 *ty != config::CrateTypeExecutable
2978 let encode_inlined_item: encoder::EncodeInlinedItem =
2979 box |ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii);
2981 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item);
2982 let metadata = encoder::encode_metadata(encode_parms, krate);
2983 let mut compressed = encoder::metadata_encoding_version.to_vec();
2984 compressed.push_all(match flate::deflate_bytes(metadata.as_slice()) {
2985 Some(compressed) => compressed,
2986 None => cx.sess().fatal("failed to compress metadata"),
2988 let llmeta = C_bytes_in_context(cx.metadata_llcx(), &compressed[]);
2989 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2990 let name = format!("rust_metadata_{}_{}",
2991 cx.link_meta().crate_name,
2992 cx.link_meta().crate_hash);
2993 let buf = CString::from_vec(name.into_bytes());
2994 let llglobal = unsafe {
2995 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(),
2999 llvm::LLVMSetInitializer(llglobal, llconst);
3000 let name = loader::meta_section_name(cx.sess().target.target.options.is_like_osx);
3001 let name = CString::from_slice(name.as_bytes());
3002 llvm::LLVMSetSection(llglobal, name.as_ptr())
3007 /// Find any symbols that are defined in one compilation unit, but not declared
3008 /// in any other compilation unit. Give these symbols internal linkage.
3009 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<String>) {
3011 let mut declared = HashSet::new();
3013 let iter_globals = |&: llmod| {
3015 cur: llvm::LLVMGetFirstGlobal(llmod),
3016 step: llvm::LLVMGetNextGlobal,
3020 let iter_functions = |&: llmod| {
3022 cur: llvm::LLVMGetFirstFunction(llmod),
3023 step: llvm::LLVMGetNextFunction,
3027 // Collect all external declarations in all compilation units.
3028 for ccx in cx.iter() {
3029 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3030 let linkage = llvm::LLVMGetLinkage(val);
3031 // We only care about external declarations (not definitions)
3032 // and available_externally definitions.
3033 if !(linkage == llvm::ExternalLinkage as c_uint &&
3034 llvm::LLVMIsDeclaration(val) != 0) &&
3035 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
3039 let name = ffi::c_str_to_bytes(&llvm::LLVMGetValueName(val))
3041 declared.insert(name);
3045 // Examine each external definition. If the definition is not used in
3046 // any other compilation unit, and is not reachable from other crates,
3047 // then give it internal linkage.
3048 for ccx in cx.iter() {
3049 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3050 // We only care about external definitions.
3051 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
3052 llvm::LLVMIsDeclaration(val) == 0) {
3056 let name = ffi::c_str_to_bytes(&llvm::LLVMGetValueName(val))
3058 if !declared.contains(&name) &&
3059 !reachable.contains(str::from_utf8(name.as_slice()).unwrap()) {
3060 llvm::SetLinkage(val, llvm::InternalLinkage);
3069 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
3072 impl Iterator for ValueIter {
3073 type Item = ValueRef;
3075 fn next(&mut self) -> Option<ValueRef> {
3079 let step: unsafe extern "C" fn(ValueRef) -> ValueRef =
3080 mem::transmute_copy(&self.step);
3091 pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
3092 -> (ty::ctxt<'tcx>, CrateTranslation) {
3093 let ty::CrateAnalysis { ty_cx: tcx, export_map, reachable, name, .. } = analysis;
3094 let krate = tcx.map.krate();
3096 // Before we touch LLVM, make sure that multithreading is enabled.
3098 use std::sync::{Once, ONCE_INIT};
3099 static INIT: Once = ONCE_INIT;
3100 static mut POISONED: bool = false;
3102 if llvm::LLVMStartMultithreaded() != 1 {
3103 // use an extra bool to make sure that all future usage of LLVM
3104 // cannot proceed despite the Once not running more than once.
3110 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3114 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3116 let codegen_units = tcx.sess.opts.cg.codegen_units;
3117 let shared_ccx = SharedCrateContext::new(&link_meta.crate_name[],
3126 let ccx = shared_ccx.get_ccx(0);
3128 // First, verify intrinsics.
3129 intrinsic::check_intrinsics(&ccx);
3131 // Next, translate the module.
3133 let _icx = push_ctxt("text");
3134 trans_mod(&ccx, &krate.module);
3138 for ccx in shared_ccx.iter() {
3139 glue::emit_tydescs(&ccx);
3140 if ccx.sess().opts.debuginfo != NoDebugInfo {
3141 debuginfo::finalize(&ccx);
3145 // Translate the metadata.
3146 let metadata = write_metadata(&shared_ccx, krate);
3148 if shared_ccx.sess().trans_stats() {
3149 let stats = shared_ccx.stats();
3150 println!("--- trans stats ---");
3151 println!("n_static_tydescs: {}", stats.n_static_tydescs.get());
3152 println!("n_glues_created: {}", stats.n_glues_created.get());
3153 println!("n_null_glues: {}", stats.n_null_glues.get());
3154 println!("n_real_glues: {}", stats.n_real_glues.get());
3156 println!("n_fns: {}", stats.n_fns.get());
3157 println!("n_monos: {}", stats.n_monos.get());
3158 println!("n_inlines: {}", stats.n_inlines.get());
3159 println!("n_closures: {}", stats.n_closures.get());
3160 println!("fn stats:");
3161 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3162 insns_b.cmp(&insns_a)
3164 for tuple in &*stats.fn_stats.borrow() {
3166 (ref name, insns) => {
3167 println!("{} insns, {}", insns, *name);
3172 if shared_ccx.sess().count_llvm_insns() {
3173 for (k, v) in &*shared_ccx.stats().llvm_insns.borrow() {
3174 println!("{:7} {}", *v, *k);
3178 let modules = shared_ccx.iter()
3179 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3182 let mut reachable: Vec<String> = shared_ccx.reachable().iter().filter_map(|id| {
3183 shared_ccx.item_symbols().borrow().get(id).map(|s| s.to_string())
3186 // For the purposes of LTO, we add to the reachable set all of the upstream
3187 // reachable extern fns. These functions are all part of the public ABI of
3188 // the final product, so LTO needs to preserve them.
3189 shared_ccx.sess().cstore.iter_crate_data(|cnum, _| {
3190 let syms = csearch::get_reachable_extern_fns(&shared_ccx.sess().cstore, cnum);
3191 reachable.extend(syms.into_iter().map(|did| {
3192 csearch::get_symbol(&shared_ccx.sess().cstore, did)
3196 // Make sure that some other crucial symbols are not eliminated from the
3197 // module. This includes the main function, the crate map (used for debug
3198 // log settings and I/O), and finally the curious rust_stack_exhausted
3199 // symbol. This symbol is required for use by the libmorestack library that
3200 // we link in, so we must ensure that this symbol is not internalized (if
3201 // defined in the crate).
3202 reachable.push("main".to_string());
3203 reachable.push("rust_stack_exhausted".to_string());
3205 // referenced from .eh_frame section on some platforms
3206 reachable.push("rust_eh_personality".to_string());
3207 // referenced from rt/rust_try.ll
3208 reachable.push("rust_eh_personality_catch".to_string());
3210 if codegen_units > 1 {
3211 internalize_symbols(&shared_ccx, &reachable.iter().map(|x| x.clone()).collect());
3214 let metadata_module = ModuleTranslation {
3215 llcx: shared_ccx.metadata_llcx(),
3216 llmod: shared_ccx.metadata_llmod(),
3218 let formats = shared_ccx.tcx().dependency_formats.borrow().clone();
3219 let no_builtins = attr::contains_name(&krate.attrs[], "no_builtins");
3221 let translation = CrateTranslation {
3223 metadata_module: metadata_module,
3226 reachable: reachable,
3227 crate_formats: formats,
3228 no_builtins: no_builtins,
3231 (shared_ccx.take_tcx(), translation)