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;
41 use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
43 use middle::weak_lang_items;
44 use middle::subst::{Subst, Substs};
45 use middle::ty::{mod, Ty};
46 use session::config::{mod, NoDebugInfo, FullDebugInfo};
51 use trans::builder::{Builder, noname};
53 use trans::cleanup::CleanupMethods;
56 use trans::common::{Block, C_bool, C_bytes_in_context, C_i32, C_integral};
57 use trans::common::{C_null, C_struct_in_context, C_u64, C_u8, C_uint, C_undef};
58 use trans::common::{CrateContext, ExternMap, FunctionContext};
59 use trans::common::{NodeInfo, Result};
60 use trans::common::{node_id_type, return_type_is_void};
61 use trans::common::{tydesc_info, type_is_immediate};
62 use trans::common::{type_is_zero_size, val_ty};
65 use trans::context::SharedCrateContext;
66 use trans::controlflow;
75 use trans::machine::{llsize_of, llsize_of_real, llalign_of_min};
77 use trans::monomorphize;
79 use trans::type_::Type;
81 use trans::type_of::*;
82 use trans::value::Value;
83 use util::common::indenter;
84 use util::ppaux::{Repr, ty_to_string};
85 use util::sha2::Sha256;
86 use util::nodemap::NodeMap;
88 use arena::TypedArena;
89 use libc::{c_uint, uint64_t};
90 use std::c_str::ToCStr;
91 use std::cell::{Cell, RefCell};
92 use std::collections::HashSet;
95 use std::{i8, i16, i32, i64};
96 use syntax::abi::{Rust, RustCall, RustIntrinsic, Abi};
97 use syntax::ast_util::local_def;
98 use syntax::attr::AttrMetaMethods;
100 use syntax::codemap::Span;
101 use syntax::parse::token::InternedString;
102 use syntax::visit::Visitor;
104 use syntax::{ast, ast_util, ast_map};
107 static TASK_LOCAL_INSN_KEY: RefCell<Option<Vec<&'static str>>> = {
112 pub fn with_insn_ctxt<F>(blk: F) where
113 F: FnOnce(&[&'static str]),
115 TASK_LOCAL_INSN_KEY.with(move |slot| {
116 slot.borrow().as_ref().map(move |s| blk(s.as_slice()));
120 pub fn init_insn_ctxt() {
121 TASK_LOCAL_INSN_KEY.with(|slot| {
122 *slot.borrow_mut() = Some(Vec::new());
126 pub struct _InsnCtxt {
127 _cannot_construct_outside_of_this_module: ()
131 impl Drop for _InsnCtxt {
133 TASK_LOCAL_INSN_KEY.with(|slot| {
134 match slot.borrow_mut().as_mut() {
135 Some(ctx) => { ctx.pop(); }
142 pub fn push_ctxt(s: &'static str) -> _InsnCtxt {
143 debug!("new InsnCtxt: {}", s);
144 TASK_LOCAL_INSN_KEY.with(|slot| {
145 match slot.borrow_mut().as_mut() {
146 Some(ctx) => ctx.push(s),
150 _InsnCtxt { _cannot_construct_outside_of_this_module: () }
153 pub struct StatRecorder<'a, 'tcx: 'a> {
154 ccx: &'a CrateContext<'a, 'tcx>,
155 name: Option<String>,
159 impl<'a, 'tcx> StatRecorder<'a, 'tcx> {
160 pub fn new(ccx: &'a CrateContext<'a, 'tcx>, name: String)
161 -> StatRecorder<'a, 'tcx> {
162 let istart = ccx.stats().n_llvm_insns.get();
172 impl<'a, 'tcx> Drop for StatRecorder<'a, 'tcx> {
174 if self.ccx.sess().trans_stats() {
175 let iend = self.ccx.stats().n_llvm_insns.get();
176 self.ccx.stats().fn_stats.borrow_mut().push((self.name.take().unwrap(),
177 iend - self.istart));
178 self.ccx.stats().n_fns.set(self.ccx.stats().n_fns.get() + 1);
179 // Reset LLVM insn count to avoid compound costs.
180 self.ccx.stats().n_llvm_insns.set(self.istart);
185 // only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
186 pub fn decl_fn(ccx: &CrateContext, name: &str, cc: llvm::CallConv,
187 ty: Type, output: ty::FnOutput) -> ValueRef {
189 let llfn: ValueRef = name.with_c_str(|buf| {
191 llvm::LLVMGetOrInsertFunction(ccx.llmod(), buf, ty.to_ref())
195 // diverging functions may unwind, but can never return normally
196 if output == ty::FnDiverging {
197 llvm::SetFunctionAttribute(llfn, llvm::NoReturnAttribute);
200 if ccx.tcx().sess.opts.cg.no_redzone
201 .unwrap_or(ccx.tcx().sess.target.target.options.disable_redzone) {
202 llvm::SetFunctionAttribute(llfn, llvm::NoRedZoneAttribute)
205 llvm::SetFunctionCallConv(llfn, cc);
206 // Function addresses in Rust are never significant, allowing functions to be merged.
207 llvm::SetUnnamedAddr(llfn, true);
209 if ccx.is_split_stack_supported() && !ccx.sess().opts.cg.no_stack_check {
210 set_split_stack(llfn);
216 // only use this for foreign function ABIs and glue, use `decl_rust_fn` for Rust functions
217 pub fn decl_cdecl_fn(ccx: &CrateContext,
220 output: Ty) -> ValueRef {
221 decl_fn(ccx, name, llvm::CCallConv, ty, ty::FnConverging(output))
224 // only use this for foreign function ABIs and glue, use `get_extern_rust_fn` for Rust functions
225 pub fn get_extern_fn(ccx: &CrateContext,
226 externs: &mut ExternMap,
232 match externs.get(name) {
233 Some(n) => return *n,
236 let f = decl_fn(ccx, name, cc, ty, ty::FnConverging(output));
237 externs.insert(name.to_string(), f);
241 fn get_extern_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>,
242 name: &str, did: ast::DefId) -> ValueRef {
243 match ccx.externs().borrow().get(name) {
244 Some(n) => return *n,
248 let f = decl_rust_fn(ccx, fn_ty, name);
250 csearch::get_item_attrs(&ccx.sess().cstore, did, |attrs| {
251 set_llvm_fn_attrs(ccx, attrs.as_slice(), 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,
262 let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
263 let unboxed_closure = &(*unboxed_closures)[closure_id];
264 match unboxed_closure.kind {
265 ty::FnUnboxedClosureKind => {
266 ty::mk_imm_rptr(ccx.tcx(), ty::ReStatic, fn_ty)
268 ty::FnMutUnboxedClosureKind => {
269 ty::mk_mut_rptr(ccx.tcx(), 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 let (inputs, output, abi, env) = match fn_ty.sty {
284 ty::ty_bare_fn(ref f) => {
285 (f.sig.0.inputs.clone(), f.sig.0.output, f.abi, None)
287 ty::ty_closure(ref f) => {
288 (f.sig.0.inputs.clone(), f.sig.0.output, f.abi, Some(Type::i8p(ccx)))
290 ty::ty_unboxed_closure(closure_did, _, ref substs) => {
291 let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
292 let unboxed_closure = &(*unboxed_closures)[closure_did];
293 let function_type = unboxed_closure.closure_type.clone();
294 let self_type = self_type_for_unboxed_closure(ccx, closure_did, fn_ty);
295 let llenvironment_type = type_of_explicit_arg(ccx, self_type);
296 (function_type.sig.0.inputs.iter().map(|t| t.subst(ccx.tcx(), substs)).collect(),
297 function_type.sig.0.output.subst(ccx.tcx(), substs),
299 Some(llenvironment_type))
301 _ => panic!("expected closure or fn")
304 let llfty = type_of_rust_fn(ccx, env, inputs.as_slice(), output, abi);
305 debug!("decl_rust_fn(input count={},type={})",
307 ccx.tn().type_to_string(llfty));
309 let llfn = decl_fn(ccx, name, llvm::CCallConv, llfty, output);
310 let attrs = get_fn_llvm_attributes(ccx, fn_ty);
311 attrs.apply_llfn(llfn);
316 pub fn decl_internal_rust_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
317 fn_ty: Ty<'tcx>, name: &str) -> ValueRef {
318 let llfn = decl_rust_fn(ccx, fn_ty, name);
319 llvm::SetLinkage(llfn, llvm::InternalLinkage);
323 pub fn get_extern_const<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, did: ast::DefId,
324 t: Ty<'tcx>) -> ValueRef {
325 let name = csearch::get_symbol(&ccx.sess().cstore, did);
326 let ty = type_of(ccx, t);
327 match ccx.externs().borrow_mut().get(&name) {
328 Some(n) => return *n,
332 let c = name.with_c_str(|buf| {
333 llvm::LLVMAddGlobal(ccx.llmod(), ty.to_ref(), buf)
335 // Thread-local statics in some other crate need to *always* be linked
336 // against in a thread-local fashion, so we need to be sure to apply the
337 // thread-local attribute locally if it was present remotely. If we
338 // don't do this then linker errors can be generated where the linker
339 // complains that one object files has a thread local version of the
340 // symbol and another one doesn't.
341 ty::each_attr(ccx.tcx(), did, |attr| {
342 if attr.check_name("thread_local") {
343 llvm::set_thread_local(c, true);
347 ccx.externs().borrow_mut().insert(name.to_string(), c);
352 // Returns a pointer to the body for the box. The box may be an opaque
353 // box. The result will be casted to the type of body_t, if it is statically
355 pub fn at_box_body<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
356 body_t: Ty<'tcx>, boxptr: ValueRef) -> ValueRef {
357 let _icx = push_ctxt("at_box_body");
359 let ty = Type::at_box(ccx, type_of(ccx, body_t));
360 let boxptr = PointerCast(bcx, boxptr, ty.ptr_to());
361 GEPi(bcx, boxptr, &[0u, abi::BOX_FIELD_BODY])
364 fn require_alloc_fn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
365 info_ty: Ty<'tcx>, it: LangItem) -> ast::DefId {
366 match bcx.tcx().lang_items.require(it) {
369 bcx.sess().fatal(format!("allocation of `{}` {}",
370 bcx.ty_to_string(info_ty),
376 // The following malloc_raw_dyn* functions allocate a box to contain
377 // a given type, but with a potentially dynamic size.
379 pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
384 -> Result<'blk, 'tcx> {
385 let _icx = push_ctxt("malloc_raw_exchange");
388 let r = callee::trans_lang_call(bcx,
389 require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem),
393 Result::new(r.bcx, PointerCast(r.bcx, r.val, llty_ptr))
396 pub fn malloc_raw_dyn_proc<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>)
397 -> Result<'blk, 'tcx> {
398 let _icx = push_ctxt("malloc_raw_dyn_proc");
401 // Grab the TypeRef type of ptr_ty.
402 let ptr_ty = ty::mk_uniq(bcx.tcx(), t);
403 let ptr_llty = type_of(ccx, ptr_ty);
405 let llty = type_of(bcx.ccx(), t);
406 let size = llsize_of(bcx.ccx(), llty);
407 let llalign = C_uint(ccx, llalign_of_min(bcx.ccx(), llty));
409 // Allocate space and store the destructor pointer:
410 let Result {bcx, val: llbox} = malloc_raw_dyn(bcx, ptr_llty, t, size, llalign);
411 let dtor_ptr = GEPi(bcx, llbox, &[0u, abi::BOX_FIELD_DROP_GLUE]);
412 let drop_glue_field_ty = type_of(ccx, ty::mk_nil_ptr(bcx.tcx()));
413 let drop_glue = PointerCast(bcx, glue::get_drop_glue(ccx, ty::mk_uniq(bcx.tcx(), t)),
415 Store(bcx, drop_glue, dtor_ptr);
417 Result::new(bcx, llbox)
420 // Type descriptor and type glue stuff
422 pub fn get_tydesc<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
423 t: Ty<'tcx>) -> Rc<tydesc_info<'tcx>> {
424 match ccx.tydescs().borrow().get(&t) {
425 Some(inf) => return inf.clone(),
429 ccx.stats().n_static_tydescs.set(ccx.stats().n_static_tydescs.get() + 1u);
430 let inf = Rc::new(glue::declare_tydesc(ccx, t));
432 ccx.tydescs().borrow_mut().insert(t, inf.clone());
436 #[allow(dead_code)] // useful
437 pub fn set_optimize_for_size(f: ValueRef) {
438 llvm::SetFunctionAttribute(f, llvm::OptimizeForSizeAttribute)
441 pub fn set_no_inline(f: ValueRef) {
442 llvm::SetFunctionAttribute(f, llvm::NoInlineAttribute)
445 #[allow(dead_code)] // useful
446 pub fn set_no_unwind(f: ValueRef) {
447 llvm::SetFunctionAttribute(f, llvm::NoUnwindAttribute)
450 // Tell LLVM to emit the information necessary to unwind the stack for the
452 pub fn set_uwtable(f: ValueRef) {
453 llvm::SetFunctionAttribute(f, llvm::UWTableAttribute)
456 pub fn set_inline_hint(f: ValueRef) {
457 llvm::SetFunctionAttribute(f, llvm::InlineHintAttribute)
460 pub fn set_llvm_fn_attrs(ccx: &CrateContext, attrs: &[ast::Attribute], llfn: ValueRef) {
462 // Set the inline hint if there is one
463 match find_inline_attr(attrs) {
464 InlineHint => set_inline_hint(llfn),
465 InlineAlways => set_always_inline(llfn),
466 InlineNever => set_no_inline(llfn),
467 InlineNone => { /* fallthrough */ }
470 for attr in attrs.iter() {
472 match attr.name().get() {
473 "no_stack_check" => unset_split_stack(llfn),
474 "no_split_stack" => {
475 unset_split_stack(llfn);
476 ccx.sess().span_warn(attr.span,
477 "no_split_stack is a deprecated synonym for no_stack_check");
480 llvm::LLVMAddFunctionAttribute(llfn,
481 llvm::FunctionIndex as c_uint,
482 llvm::ColdAttribute as uint64_t)
487 attr::mark_used(attr);
492 pub fn set_always_inline(f: ValueRef) {
493 llvm::SetFunctionAttribute(f, llvm::AlwaysInlineAttribute)
496 pub fn set_split_stack(f: ValueRef) {
497 "split-stack".with_c_str(|buf| {
498 unsafe { llvm::LLVMAddFunctionAttrString(f, llvm::FunctionIndex as c_uint, buf); }
502 pub fn unset_split_stack(f: ValueRef) {
503 "split-stack".with_c_str(|buf| {
504 unsafe { llvm::LLVMRemoveFunctionAttrString(f, llvm::FunctionIndex as c_uint, buf); }
508 // Double-check that we never ask LLVM to declare the same symbol twice. It
509 // silently mangles such symbols, breaking our linkage model.
510 pub fn note_unique_llvm_symbol(ccx: &CrateContext, sym: String) {
511 if ccx.all_llvm_symbols().borrow().contains(&sym) {
512 ccx.sess().bug(format!("duplicate LLVM symbol: {}", sym).as_slice());
514 ccx.all_llvm_symbols().borrow_mut().insert(sym);
518 pub fn get_res_dtor<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
521 parent_id: ast::DefId,
522 substs: &subst::Substs<'tcx>)
524 let _icx = push_ctxt("trans_res_dtor");
525 let did = inline::maybe_instantiate_inline(ccx, did);
527 if !substs.types.is_empty() {
528 assert_eq!(did.krate, ast::LOCAL_CRATE);
530 // Since we're in trans we don't care for any region parameters
531 let ref substs = subst::Substs::erased(substs.types.clone());
533 let (val, _) = monomorphize::monomorphic_fn(ccx, did, substs, None);
536 } else if did.krate == ast::LOCAL_CRATE {
537 get_item_val(ccx, did.node)
540 let name = csearch::get_symbol(&ccx.sess().cstore, did);
541 let class_ty = ty::lookup_item_type(tcx, parent_id).ty.subst(tcx, substs);
542 let llty = type_of_dtor(ccx, class_ty);
543 let dtor_ty = ty::mk_ctor_fn(ccx.tcx(),
544 &[glue::get_drop_glue_type(ccx, t)],
545 ty::mk_nil(ccx.tcx()));
547 &mut *ccx.externs().borrow_mut(),
555 // Structural comparison: a rather involved form of glue.
556 pub fn maybe_name_value(cx: &CrateContext, v: ValueRef, s: &str) {
557 if cx.sess().opts.cg.save_temps {
560 llvm::LLVMSetValueName(v, buf)
567 // Used only for creating scalar comparison glue.
569 pub enum scalar_type { nil_type, signed_int, unsigned_int, floating_point, }
571 pub fn compare_scalar_types<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
576 -> Result<'blk, 'tcx> {
577 let f = |a| Result::new(cx, compare_scalar_values(cx, lhs, rhs, a, op));
580 ty::ty_tup(ref tys) if tys.is_empty() => f(nil_type),
581 ty::ty_bool | ty::ty_uint(_) | ty::ty_char => f(unsigned_int),
582 ty::ty_ptr(mt) if ty::type_is_sized(cx.tcx(), mt.ty) => f(unsigned_int),
583 ty::ty_int(_) => f(signed_int),
584 ty::ty_float(_) => f(floating_point),
585 // Should never get here, because t is scalar.
586 _ => cx.sess().bug("non-scalar type passed to compare_scalar_types")
591 // A helper function to do the actual comparison of scalar values.
592 pub fn compare_scalar_values<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
598 let _icx = push_ctxt("compare_scalar_values");
599 fn die(cx: Block) -> ! {
600 cx.sess().bug("compare_scalar_values: must be a comparison operator");
604 // We don't need to do actual comparisons for nil.
605 // () == () holds but () < () does not.
607 ast::BiEq | ast::BiLe | ast::BiGe => return C_bool(cx.ccx(), true),
608 ast::BiNe | ast::BiLt | ast::BiGt => return C_bool(cx.ccx(), false),
609 // refinements would be nice
615 ast::BiEq => llvm::RealOEQ,
616 ast::BiNe => llvm::RealUNE,
617 ast::BiLt => llvm::RealOLT,
618 ast::BiLe => llvm::RealOLE,
619 ast::BiGt => llvm::RealOGT,
620 ast::BiGe => llvm::RealOGE,
623 return FCmp(cx, cmp, lhs, rhs);
627 ast::BiEq => llvm::IntEQ,
628 ast::BiNe => llvm::IntNE,
629 ast::BiLt => llvm::IntSLT,
630 ast::BiLe => llvm::IntSLE,
631 ast::BiGt => llvm::IntSGT,
632 ast::BiGe => llvm::IntSGE,
635 return ICmp(cx, cmp, lhs, rhs);
639 ast::BiEq => llvm::IntEQ,
640 ast::BiNe => llvm::IntNE,
641 ast::BiLt => llvm::IntULT,
642 ast::BiLe => llvm::IntULE,
643 ast::BiGt => llvm::IntUGT,
644 ast::BiGe => llvm::IntUGE,
647 return ICmp(cx, cmp, lhs, rhs);
652 pub fn compare_simd_types<'blk, 'tcx>(
653 cx: Block<'blk, 'tcx>,
662 // The comparison operators for floating point vectors are challenging.
663 // LLVM outputs a `< size x i1 >`, but if we perform a sign extension
664 // then bitcast to a floating point vector, the result will be `-NaN`
665 // for each truth value. Because of this they are unsupported.
666 cx.sess().bug("compare_simd_types: comparison operators \
667 not supported for floating point SIMD types")
669 ty::ty_uint(_) | ty::ty_int(_) => {
671 ast::BiEq => llvm::IntEQ,
672 ast::BiNe => llvm::IntNE,
673 ast::BiLt => llvm::IntSLT,
674 ast::BiLe => llvm::IntSLE,
675 ast::BiGt => llvm::IntSGT,
676 ast::BiGe => llvm::IntSGE,
677 _ => cx.sess().bug("compare_simd_types: must be a comparison operator"),
679 let return_ty = Type::vector(&type_of(cx.ccx(), t), size as u64);
680 // LLVM outputs an `< size x i1 >`, so we need to perform a sign extension
681 // to get the correctly sized type. This will compile to a single instruction
682 // once the IR is converted to assembly if the SIMD instruction is supported
683 // by the target architecture.
684 SExt(cx, ICmp(cx, cmp, lhs, rhs), return_ty)
686 _ => cx.sess().bug("compare_simd_types: invalid SIMD type"),
690 pub type val_and_ty_fn<'a, 'blk, 'tcx> =
691 |Block<'blk, 'tcx>, ValueRef, Ty<'tcx>|: 'a -> Block<'blk, 'tcx>;
693 // Iterates through the elements of a structural type.
694 pub fn iter_structural_ty<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
697 f: val_and_ty_fn<'a, 'blk, 'tcx>)
698 -> Block<'blk, 'tcx> {
699 let _icx = push_ctxt("iter_structural_ty");
701 fn iter_variant<'a, 'blk, 'tcx>(cx: Block<'blk, 'tcx>,
702 repr: &adt::Repr<'tcx>,
704 variant: &ty::VariantInfo<'tcx>,
705 substs: &subst::Substs<'tcx>,
706 f: val_and_ty_fn<'a, 'blk, 'tcx>)
707 -> Block<'blk, 'tcx> {
708 let _icx = push_ctxt("iter_variant");
712 for (i, &arg) in variant.args.iter().enumerate() {
714 adt::trans_field_ptr(cx, repr, av, variant.disr_val, i),
715 arg.subst(tcx, substs));
720 let (data_ptr, info) = if ty::type_is_sized(cx.tcx(), t) {
723 let data = GEPi(cx, av, &[0, abi::FAT_PTR_ADDR]);
724 let info = GEPi(cx, av, &[0, abi::FAT_PTR_EXTRA]);
725 (Load(cx, data), Some(Load(cx, info)))
730 ty::ty_struct(..) => {
731 let repr = adt::represent_type(cx.ccx(), t);
732 expr::with_field_tys(cx.tcx(), t, None, |discr, field_tys| {
733 for (i, field_ty) in field_tys.iter().enumerate() {
734 let field_ty = field_ty.mt.ty;
735 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, discr, i);
737 let val = if ty::type_is_sized(cx.tcx(), field_ty) {
740 let boxed_ty = ty::mk_open(cx.tcx(), field_ty);
741 let scratch = datum::rvalue_scratch_datum(cx, boxed_ty, "__fat_ptr_iter");
742 Store(cx, llfld_a, GEPi(cx, scratch.val, &[0, abi::FAT_PTR_ADDR]));
743 Store(cx, info.unwrap(), GEPi(cx, scratch.val, &[0, abi::FAT_PTR_EXTRA]));
746 cx = f(cx, val, field_ty);
750 ty::ty_unboxed_closure(def_id, _, ref substs) => {
751 let repr = adt::represent_type(cx.ccx(), t);
752 let upvars = ty::unboxed_closure_upvars(cx.tcx(), def_id, substs);
753 for (i, upvar) in upvars.iter().enumerate() {
754 let llupvar = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
755 cx = f(cx, llupvar, upvar.ty);
758 ty::ty_vec(_, Some(n)) => {
759 let (base, len) = tvec::get_fixed_base_and_len(cx, data_ptr, n);
760 let unit_ty = ty::sequence_element_type(cx.tcx(), t);
761 cx = tvec::iter_vec_raw(cx, base, unit_ty, len, f);
763 ty::ty_tup(ref args) => {
764 let repr = adt::represent_type(cx.ccx(), t);
765 for (i, arg) in args.iter().enumerate() {
766 let llfld_a = adt::trans_field_ptr(cx, &*repr, data_ptr, 0, i);
767 cx = f(cx, llfld_a, *arg);
770 ty::ty_enum(tid, ref substs) => {
774 let repr = adt::represent_type(ccx, t);
775 let variants = ty::enum_variants(ccx.tcx(), tid);
776 let n_variants = (*variants).len();
778 // NB: we must hit the discriminant first so that structural
779 // comparison know not to proceed when the discriminants differ.
781 match adt::trans_switch(cx, &*repr, av) {
782 (_match::Single, None) => {
783 cx = iter_variant(cx, &*repr, av, &*(*variants)[0],
786 (_match::Switch, Some(lldiscrim_a)) => {
787 cx = f(cx, lldiscrim_a, ty::mk_int());
788 let unr_cx = fcx.new_temp_block("enum-iter-unr");
790 let llswitch = Switch(cx, lldiscrim_a, unr_cx.llbb,
792 let next_cx = fcx.new_temp_block("enum-iter-next");
794 for variant in (*variants).iter() {
797 format!("enum-iter-variant-{}",
798 variant.disr_val.to_string().as_slice())
800 match adt::trans_case(cx, &*repr, variant.disr_val) {
801 _match::SingleResult(r) => {
802 AddCase(llswitch, r.val, variant_cx.llbb)
804 _ => ccx.sess().unimpl("value from adt::trans_case \
805 in iter_structural_ty")
808 iter_variant(variant_cx,
814 Br(variant_cx, next_cx.llbb);
818 _ => ccx.sess().unimpl("value from adt::trans_switch \
819 in iter_structural_ty")
823 cx.sess().unimpl(format!("type in iter_structural_ty: {}",
824 ty_to_string(cx.tcx(), t)).as_slice())
830 pub fn cast_shift_expr_rhs(cx: Block,
835 cast_shift_rhs(op, lhs, rhs,
836 |a,b| Trunc(cx, a, b),
837 |a,b| ZExt(cx, a, b))
840 pub fn cast_shift_const_rhs(op: ast::BinOp,
841 lhs: ValueRef, rhs: ValueRef) -> ValueRef {
842 cast_shift_rhs(op, lhs, rhs,
843 |a, b| unsafe { llvm::LLVMConstTrunc(a, b.to_ref()) },
844 |a, b| unsafe { llvm::LLVMConstZExt(a, b.to_ref()) })
847 pub fn cast_shift_rhs<F, G>(op: ast::BinOp,
853 F: FnOnce(ValueRef, Type) -> ValueRef,
854 G: FnOnce(ValueRef, Type) -> ValueRef,
856 // Shifts may have any size int on the rhs
858 if ast_util::is_shift_binop(op) {
859 let mut rhs_llty = val_ty(rhs);
860 let mut lhs_llty = val_ty(lhs);
861 if rhs_llty.kind() == Vector { rhs_llty = rhs_llty.element_type() }
862 if lhs_llty.kind() == Vector { lhs_llty = lhs_llty.element_type() }
863 let rhs_sz = llvm::LLVMGetIntTypeWidth(rhs_llty.to_ref());
864 let lhs_sz = llvm::LLVMGetIntTypeWidth(lhs_llty.to_ref());
867 } else if lhs_sz > rhs_sz {
868 // FIXME (#1877: If shifting by negative
869 // values becomes not undefined then this is wrong.
880 pub fn fail_if_zero_or_overflows<'blk, 'tcx>(
881 cx: Block<'blk, 'tcx>,
887 -> Block<'blk, 'tcx> {
888 let (zero_text, overflow_text) = if divrem == ast::BiDiv {
889 ("attempted to divide by zero",
890 "attempted to divide with overflow")
892 ("attempted remainder with a divisor of zero",
893 "attempted remainder with overflow")
895 let (is_zero, is_signed) = match rhs_t.sty {
897 let zero = C_integral(Type::int_from_ty(cx.ccx(), t), 0u64, false);
898 (ICmp(cx, llvm::IntEQ, rhs, zero), true)
901 let zero = C_integral(Type::uint_from_ty(cx.ccx(), t), 0u64, false);
902 (ICmp(cx, llvm::IntEQ, rhs, zero), false)
905 cx.sess().bug(format!("fail-if-zero on unexpected type: {}",
906 ty_to_string(cx.tcx(), rhs_t)).as_slice());
909 let bcx = with_cond(cx, is_zero, |bcx| {
910 controlflow::trans_fail(bcx, span, InternedString::new(zero_text))
913 // To quote LLVM's documentation for the sdiv instruction:
915 // Division by zero leads to undefined behavior. Overflow also leads
916 // to undefined behavior; this is a rare case, but can occur, for
917 // example, by doing a 32-bit division of -2147483648 by -1.
919 // In order to avoid undefined behavior, we perform runtime checks for
920 // signed division/remainder which would trigger overflow. For unsigned
921 // integers, no action beyond checking for zero need be taken.
923 let (llty, min) = match rhs_t.sty {
925 let llty = Type::int_from_ty(cx.ccx(), t);
927 ast::TyI if llty == Type::i32(cx.ccx()) => i32::MIN as u64,
928 ast::TyI => i64::MIN as u64,
929 ast::TyI8 => i8::MIN as u64,
930 ast::TyI16 => i16::MIN as u64,
931 ast::TyI32 => i32::MIN as u64,
932 ast::TyI64 => i64::MIN as u64,
938 let minus_one = ICmp(bcx, llvm::IntEQ, rhs,
939 C_integral(llty, -1, false));
940 with_cond(bcx, minus_one, |bcx| {
941 let is_min = ICmp(bcx, llvm::IntEQ, lhs,
942 C_integral(llty, min, true));
943 with_cond(bcx, is_min, |bcx| {
944 controlflow::trans_fail(bcx, span,
945 InternedString::new(overflow_text))
953 pub fn trans_external_path<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
954 did: ast::DefId, t: Ty<'tcx>) -> ValueRef {
955 let name = csearch::get_symbol(&ccx.sess().cstore, did);
957 ty::ty_bare_fn(ref fn_ty) => {
958 match ccx.sess().target.target.adjust_abi(fn_ty.abi) {
960 get_extern_rust_fn(ccx, t, name.as_slice(), did)
963 ccx.sess().bug("unexpected intrinsic in trans_external_path")
966 foreign::register_foreign_item_fn(ccx, fn_ty.abi, t,
971 ty::ty_closure(_) => {
972 get_extern_rust_fn(ccx, t, name.as_slice(), did)
975 get_extern_const(ccx, did, t)
980 pub fn invoke<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
984 call_info: Option<NodeInfo>,
985 // FIXME(15064) is_lang_item is a horrible hack, please remove it
986 // at the soonest opportunity.
988 -> (ValueRef, Block<'blk, 'tcx>) {
989 let _icx = push_ctxt("invoke_");
990 if bcx.unreachable.get() {
991 return (C_null(Type::i8(bcx.ccx())), bcx);
994 // FIXME(15064) Lang item methods may (in the reflect case) not have proper
995 // types, so doing an attribute lookup will fail.
996 let attributes = if is_lang_item {
997 llvm::AttrBuilder::new()
999 get_fn_llvm_attributes(bcx.ccx(), fn_ty)
1002 match bcx.opt_node_id {
1004 debug!("invoke at ???");
1007 debug!("invoke at {}", bcx.tcx().map.node_to_string(id));
1011 if need_invoke(bcx) {
1012 debug!("invoking {} at {}", bcx.val_to_string(llfn), bcx.llbb);
1013 for &llarg in llargs.iter() {
1014 debug!("arg: {}", bcx.val_to_string(llarg));
1016 let normal_bcx = bcx.fcx.new_temp_block("normal-return");
1017 let landing_pad = bcx.fcx.get_landing_pad();
1020 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
1021 None => debuginfo::clear_source_location(bcx.fcx)
1024 let llresult = Invoke(bcx,
1030 return (llresult, normal_bcx);
1032 debug!("calling {} at {}", bcx.val_to_string(llfn), bcx.llbb);
1033 for &llarg in llargs.iter() {
1034 debug!("arg: {}", bcx.val_to_string(llarg));
1038 Some(info) => debuginfo::set_source_location(bcx.fcx, info.id, info.span),
1039 None => debuginfo::clear_source_location(bcx.fcx)
1042 let llresult = Call(bcx, llfn, llargs.as_slice(), Some(attributes));
1043 return (llresult, bcx);
1047 pub fn need_invoke(bcx: Block) -> bool {
1048 if bcx.sess().no_landing_pads() {
1052 // Avoid using invoke if we are already inside a landing pad.
1057 bcx.fcx.needs_invoke()
1060 pub fn load_if_immediate<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1061 v: ValueRef, t: Ty<'tcx>) -> ValueRef {
1062 let _icx = push_ctxt("load_if_immediate");
1063 if type_is_immediate(cx.ccx(), t) { return load_ty(cx, v, t); }
1067 /// Helper for loading values from memory. Does the necessary conversion if the in-memory type
1068 /// differs from the type used for SSA values. Also handles various special cases where the type
1069 /// gives us better information about what we are loading.
1070 pub fn load_ty<'blk, 'tcx>(cx: Block<'blk, 'tcx>,
1071 ptr: ValueRef, t: Ty<'tcx>) -> ValueRef {
1072 if type_is_zero_size(cx.ccx(), t) {
1073 C_undef(type_of::type_of(cx.ccx(), t))
1074 } else if ty::type_is_bool(t) {
1075 Trunc(cx, LoadRangeAssert(cx, ptr, 0, 2, llvm::False), Type::i1(cx.ccx()))
1076 } else if ty::type_is_char(t) {
1077 // a char is a Unicode codepoint, and so takes values from 0
1078 // to 0x10FFFF inclusive only.
1079 LoadRangeAssert(cx, ptr, 0, 0x10FFFF + 1, llvm::False)
1085 /// Helper for storing values in memory. Does the necessary conversion if the in-memory type
1086 /// differs from the type used for SSA values.
1087 pub fn store_ty(cx: Block, v: ValueRef, dst: ValueRef, t: Ty) {
1088 if ty::type_is_bool(t) {
1089 Store(cx, ZExt(cx, v, Type::i8(cx.ccx())), dst);
1095 pub fn init_local<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, local: &ast::Local)
1096 -> Block<'blk, 'tcx> {
1097 debug!("init_local(bcx={}, local.id={})", bcx.to_str(), local.id);
1098 let _indenter = indenter();
1099 let _icx = push_ctxt("init_local");
1100 _match::store_local(bcx, local)
1103 pub fn raw_block<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1105 llbb: BasicBlockRef)
1106 -> Block<'blk, 'tcx> {
1107 common::BlockS::new(llbb, is_lpad, None, fcx)
1110 pub fn with_cond<'blk, 'tcx, F>(bcx: Block<'blk, 'tcx>,
1113 -> Block<'blk, 'tcx> where
1114 F: FnOnce(Block<'blk, 'tcx>) -> Block<'blk, 'tcx>,
1116 let _icx = push_ctxt("with_cond");
1118 let next_cx = fcx.new_temp_block("next");
1119 let cond_cx = fcx.new_temp_block("cond");
1120 CondBr(bcx, val, cond_cx.llbb, next_cx.llbb);
1121 let after_cx = f(cond_cx);
1122 if !after_cx.terminated.get() {
1123 Br(after_cx, next_cx.llbb);
1128 pub fn call_lifetime_start(cx: Block, ptr: ValueRef) {
1129 if cx.sess().opts.optimize == config::No {
1133 let _icx = push_ctxt("lifetime_start");
1136 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1137 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1138 let lifetime_start = ccx.get_intrinsic(&"llvm.lifetime.start");
1139 Call(cx, lifetime_start, &[llsize, ptr], None);
1142 pub fn call_lifetime_end(cx: Block, ptr: ValueRef) {
1143 if cx.sess().opts.optimize == config::No {
1147 let _icx = push_ctxt("lifetime_end");
1150 let llsize = C_u64(ccx, machine::llsize_of_alloc(ccx, val_ty(ptr).element_type()));
1151 let ptr = PointerCast(cx, ptr, Type::i8p(ccx));
1152 let lifetime_end = ccx.get_intrinsic(&"llvm.lifetime.end");
1153 Call(cx, lifetime_end, &[llsize, ptr], None);
1156 pub fn call_memcpy(cx: Block, dst: ValueRef, src: ValueRef, n_bytes: ValueRef, align: u32) {
1157 let _icx = push_ctxt("call_memcpy");
1159 let key = match ccx.sess().target.target.target_word_size.as_slice() {
1160 "32" => "llvm.memcpy.p0i8.p0i8.i32",
1161 "64" => "llvm.memcpy.p0i8.p0i8.i64",
1162 tws => panic!("Unsupported target word size for memcpy: {}", tws),
1164 let memcpy = ccx.get_intrinsic(&key);
1165 let src_ptr = PointerCast(cx, src, Type::i8p(ccx));
1166 let dst_ptr = PointerCast(cx, dst, Type::i8p(ccx));
1167 let size = IntCast(cx, n_bytes, ccx.int_type());
1168 let align = C_i32(ccx, align as i32);
1169 let volatile = C_bool(ccx, false);
1170 Call(cx, memcpy, &[dst_ptr, src_ptr, size, align, volatile], None);
1173 pub fn memcpy_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>,
1174 dst: ValueRef, src: ValueRef,
1176 let _icx = push_ctxt("memcpy_ty");
1177 let ccx = bcx.ccx();
1178 if ty::type_is_structural(t) {
1179 let llty = type_of::type_of(ccx, t);
1180 let llsz = llsize_of(ccx, llty);
1181 let llalign = type_of::align_of(ccx, t);
1182 call_memcpy(bcx, dst, src, llsz, llalign as u32);
1184 store_ty(bcx, Load(bcx, src), dst, t);
1188 pub fn zero_mem<'blk, 'tcx>(cx: Block<'blk, 'tcx>, llptr: ValueRef, t: Ty<'tcx>) {
1189 if cx.unreachable.get() { return; }
1190 let _icx = push_ctxt("zero_mem");
1192 memzero(&B(bcx), llptr, t);
1195 // Always use this function instead of storing a zero constant to the memory
1196 // in question. If you store a zero constant, LLVM will drown in vreg
1197 // allocation for large data structures, and the generated code will be
1198 // awful. (A telltale sign of this is large quantities of
1199 // `mov [byte ptr foo],0` in the generated code.)
1200 fn memzero<'a, 'tcx>(b: &Builder<'a, 'tcx>, llptr: ValueRef, ty: Ty<'tcx>) {
1201 let _icx = push_ctxt("memzero");
1204 let llty = type_of::type_of(ccx, ty);
1206 let intrinsic_key = match ccx.sess().target.target.target_word_size.as_slice() {
1207 "32" => "llvm.memset.p0i8.i32",
1208 "64" => "llvm.memset.p0i8.i64",
1209 tws => panic!("Unsupported target word size for memset: {}", tws),
1212 let llintrinsicfn = ccx.get_intrinsic(&intrinsic_key);
1213 let llptr = b.pointercast(llptr, Type::i8(ccx).ptr_to());
1214 let llzeroval = C_u8(ccx, 0);
1215 let size = machine::llsize_of(ccx, llty);
1216 let align = C_i32(ccx, type_of::align_of(ccx, ty) as i32);
1217 let volatile = C_bool(ccx, false);
1218 b.call(llintrinsicfn, &[llptr, llzeroval, size, align, volatile], None);
1221 pub fn alloc_ty<'blk, 'tcx>(bcx: Block<'blk, 'tcx>, t: Ty<'tcx>, name: &str) -> ValueRef {
1222 let _icx = push_ctxt("alloc_ty");
1223 let ccx = bcx.ccx();
1224 let ty = type_of::type_of(ccx, t);
1225 assert!(!ty::type_has_params(t));
1226 let val = alloca(bcx, ty, name);
1230 pub fn alloca(cx: Block, ty: Type, name: &str) -> ValueRef {
1231 let p = alloca_no_lifetime(cx, ty, name);
1232 call_lifetime_start(cx, p);
1236 pub fn alloca_no_lifetime(cx: Block, ty: Type, name: &str) -> ValueRef {
1237 let _icx = push_ctxt("alloca");
1238 if cx.unreachable.get() {
1240 return llvm::LLVMGetUndef(ty.ptr_to().to_ref());
1243 debuginfo::clear_source_location(cx.fcx);
1244 Alloca(cx, ty, name)
1247 pub fn alloca_zeroed<'blk, 'tcx>(cx: Block<'blk, 'tcx>, ty: Ty<'tcx>,
1248 name: &str) -> ValueRef {
1249 let llty = type_of::type_of(cx.ccx(), ty);
1250 if cx.unreachable.get() {
1252 return llvm::LLVMGetUndef(llty.ptr_to().to_ref());
1255 let p = alloca_no_lifetime(cx, llty, name);
1256 let b = cx.fcx.ccx.builder();
1257 b.position_before(cx.fcx.alloca_insert_pt.get().unwrap());
1262 pub fn arrayalloca(cx: Block, ty: Type, v: ValueRef) -> ValueRef {
1263 let _icx = push_ctxt("arrayalloca");
1264 if cx.unreachable.get() {
1266 return llvm::LLVMGetUndef(ty.to_ref());
1269 debuginfo::clear_source_location(cx.fcx);
1270 let p = ArrayAlloca(cx, ty, v);
1271 call_lifetime_start(cx, p);
1275 // Creates the alloca slot which holds the pointer to the slot for the final return value
1276 pub fn make_return_slot_pointer<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1277 output_type: Ty<'tcx>) -> ValueRef {
1278 let lloutputtype = type_of::type_of(fcx.ccx, output_type);
1280 // We create an alloca to hold a pointer of type `output_type`
1281 // which will hold the pointer to the right alloca which has the
1283 if fcx.needs_ret_allocas {
1284 // Let's create the stack slot
1285 let slot = AllocaFcx(fcx, lloutputtype.ptr_to(), "llretslotptr");
1287 // and if we're using an out pointer, then store that in our newly made slot
1288 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1289 let outptr = get_param(fcx.llfn, 0);
1291 let b = fcx.ccx.builder();
1292 b.position_before(fcx.alloca_insert_pt.get().unwrap());
1293 b.store(outptr, slot);
1298 // But if there are no nested returns, we skip the indirection and have a single
1301 if type_of::return_uses_outptr(fcx.ccx, output_type) {
1302 get_param(fcx.llfn, 0)
1304 AllocaFcx(fcx, lloutputtype, "sret_slot")
1309 struct CheckForNestedReturnsVisitor {
1314 impl CheckForNestedReturnsVisitor {
1315 fn explicit() -> CheckForNestedReturnsVisitor {
1316 CheckForNestedReturnsVisitor { found: false, in_return: false }
1318 fn implicit() -> CheckForNestedReturnsVisitor {
1319 CheckForNestedReturnsVisitor { found: false, in_return: true }
1323 impl<'v> Visitor<'v> for CheckForNestedReturnsVisitor {
1324 fn visit_expr(&mut self, e: &ast::Expr) {
1326 ast::ExprRet(..) => {
1330 self.in_return = true;
1331 visit::walk_expr(self, e);
1332 self.in_return = false;
1335 _ => visit::walk_expr(self, e)
1340 fn has_nested_returns(tcx: &ty::ctxt, id: ast::NodeId) -> bool {
1341 match tcx.map.find(id) {
1342 Some(ast_map::NodeItem(i)) => {
1344 ast::ItemFn(_, _, _, _, ref blk) => {
1345 let mut explicit = CheckForNestedReturnsVisitor::explicit();
1346 let mut implicit = CheckForNestedReturnsVisitor::implicit();
1347 visit::walk_item(&mut explicit, &*i);
1348 visit::walk_expr_opt(&mut implicit, &blk.expr);
1349 explicit.found || implicit.found
1351 _ => tcx.sess.bug("unexpected item variant in has_nested_returns")
1354 Some(ast_map::NodeTraitItem(trait_method)) => {
1355 match *trait_method {
1356 ast::ProvidedMethod(ref m) => {
1358 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1359 let mut explicit = CheckForNestedReturnsVisitor::explicit();
1360 let mut implicit = CheckForNestedReturnsVisitor::implicit();
1361 visit::walk_method_helper(&mut explicit, &**m);
1362 visit::walk_expr_opt(&mut implicit, &blk.expr);
1363 explicit.found || implicit.found
1365 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1368 ast::RequiredMethod(_) => {
1369 tcx.sess.bug("unexpected variant: required trait method \
1370 in has_nested_returns")
1372 ast::TypeTraitItem(_) => {
1373 tcx.sess.bug("unexpected variant: type trait item in \
1374 has_nested_returns")
1378 Some(ast_map::NodeImplItem(ii)) => {
1380 ast::MethodImplItem(ref m) => {
1382 ast::MethDecl(_, _, _, _, _, _, ref blk, _) => {
1383 let mut explicit = CheckForNestedReturnsVisitor::explicit();
1384 let mut implicit = CheckForNestedReturnsVisitor::implicit();
1385 visit::walk_method_helper(&mut explicit, &**m);
1386 visit::walk_expr_opt(&mut implicit, &blk.expr);
1387 explicit.found || implicit.found
1389 ast::MethMac(_) => tcx.sess.bug("unexpanded macro")
1392 ast::TypeImplItem(_) => {
1393 tcx.sess.bug("unexpected variant: type impl item in \
1394 has_nested_returns")
1398 Some(ast_map::NodeExpr(e)) => {
1400 ast::ExprClosure(_, _, _, ref blk) => {
1401 let mut explicit = CheckForNestedReturnsVisitor::explicit();
1402 let mut implicit = CheckForNestedReturnsVisitor::implicit();
1403 visit::walk_expr(&mut explicit, e);
1404 visit::walk_expr_opt(&mut implicit, &blk.expr);
1405 explicit.found || implicit.found
1407 _ => tcx.sess.bug("unexpected expr variant in has_nested_returns")
1411 Some(ast_map::NodeVariant(..)) | Some(ast_map::NodeStructCtor(..)) => false,
1414 None if id == ast::DUMMY_NODE_ID => false,
1416 _ => tcx.sess.bug(format!("unexpected variant in has_nested_returns: {}",
1417 tcx.map.path_to_string(id)).as_slice())
1421 // NB: must keep 4 fns in sync:
1424 // - create_datums_for_fn_args.
1428 // Be warned! You must call `init_function` before doing anything with the
1429 // returned function context.
1430 pub fn new_fn_ctxt<'a, 'tcx>(ccx: &'a CrateContext<'a, 'tcx>,
1434 output_type: ty::FnOutput<'tcx>,
1435 param_substs: &'a Substs<'tcx>,
1437 block_arena: &'a TypedArena<common::BlockS<'a, 'tcx>>)
1438 -> FunctionContext<'a, 'tcx> {
1439 common::validate_substs(param_substs);
1441 debug!("new_fn_ctxt(path={}, id={}, param_substs={})",
1445 ccx.tcx().map.path_to_string(id).to_string()
1447 id, param_substs.repr(ccx.tcx()));
1449 let uses_outptr = match output_type {
1450 ty::FnConverging(output_type) => {
1451 let substd_output_type = output_type.subst(ccx.tcx(), param_substs);
1452 type_of::return_uses_outptr(ccx, substd_output_type)
1454 ty::FnDiverging => false
1456 let debug_context = debuginfo::create_function_debug_context(ccx, id, param_substs, llfndecl);
1457 let nested_returns = has_nested_returns(ccx.tcx(), id);
1459 let mut fcx = FunctionContext {
1462 llretslotptr: Cell::new(None),
1463 alloca_insert_pt: Cell::new(None),
1464 llreturn: Cell::new(None),
1465 needs_ret_allocas: nested_returns,
1466 personality: Cell::new(None),
1467 caller_expects_out_pointer: uses_outptr,
1468 lllocals: RefCell::new(NodeMap::new()),
1469 llupvars: RefCell::new(NodeMap::new()),
1471 param_substs: param_substs,
1473 block_arena: block_arena,
1475 debug_context: debug_context,
1476 scopes: RefCell::new(Vec::new())
1480 fcx.llenv = Some(get_param(fcx.llfn, fcx.env_arg_pos() as c_uint))
1486 /// Performs setup on a newly created function, creating the entry scope block
1487 /// and allocating space for the return pointer.
1488 pub fn init_function<'a, 'tcx>(fcx: &'a FunctionContext<'a, 'tcx>,
1490 output: ty::FnOutput<'tcx>)
1491 -> Block<'a, 'tcx> {
1492 let entry_bcx = fcx.new_temp_block("entry-block");
1494 // Use a dummy instruction as the insertion point for all allocas.
1495 // This is later removed in FunctionContext::cleanup.
1496 fcx.alloca_insert_pt.set(Some(unsafe {
1497 Load(entry_bcx, C_null(Type::i8p(fcx.ccx)));
1498 llvm::LLVMGetFirstInstruction(entry_bcx.llbb)
1501 if let ty::FnConverging(output_type) = output {
1502 // This shouldn't need to recompute the return type,
1503 // as new_fn_ctxt did it already.
1504 let substd_output_type = output_type.subst(fcx.ccx.tcx(), fcx.param_substs);
1505 if !return_type_is_void(fcx.ccx, substd_output_type) {
1506 // If the function returns nil/bot, there is no real return
1507 // value, so do not set `llretslotptr`.
1508 if !skip_retptr || fcx.caller_expects_out_pointer {
1509 // Otherwise, we normally allocate the llretslotptr, unless we
1510 // have been instructed to skip it for immediate return
1512 fcx.llretslotptr.set(Some(make_return_slot_pointer(fcx, substd_output_type)));
1520 // NB: must keep 4 fns in sync:
1523 // - create_datums_for_fn_args.
1527 pub fn arg_kind<'a, 'tcx>(cx: &FunctionContext<'a, 'tcx>, t: Ty<'tcx>)
1529 use trans::datum::{ByRef, ByValue};
1532 mode: if arg_is_indirect(cx.ccx, t) { ByRef } else { ByValue }
1536 // work around bizarre resolve errors
1537 pub type RvalueDatum<'tcx> = datum::Datum<'tcx, datum::Rvalue>;
1538 pub type LvalueDatum<'tcx> = datum::Datum<'tcx, datum::Lvalue>;
1540 // create_datums_for_fn_args: creates rvalue datums for each of the
1541 // incoming function arguments. These will later be stored into
1542 // appropriate lvalue datums.
1543 pub fn create_datums_for_fn_args<'a, 'tcx>(fcx: &FunctionContext<'a, 'tcx>,
1544 arg_tys: &[Ty<'tcx>])
1545 -> Vec<RvalueDatum<'tcx>> {
1546 let _icx = push_ctxt("create_datums_for_fn_args");
1548 // Return an array wrapping the ValueRefs that we get from `get_param` for
1549 // each argument into datums.
1550 arg_tys.iter().enumerate().map(|(i, &arg_ty)| {
1551 let llarg = get_param(fcx.llfn, fcx.arg_pos(i) as c_uint);
1552 datum::Datum::new(llarg, arg_ty, arg_kind(fcx, arg_ty))
1556 /// Creates rvalue datums for each of the incoming function arguments and
1557 /// tuples the arguments. These will later be stored into appropriate lvalue
1560 /// FIXME(pcwalton): Reduce the amount of code bloat this is responsible for.
1561 fn create_datums_for_fn_args_under_call_abi<'blk, 'tcx>(
1562 mut bcx: Block<'blk, 'tcx>,
1563 arg_scope: cleanup::CustomScopeIndex,
1564 arg_tys: &[Ty<'tcx>])
1565 -> Vec<RvalueDatum<'tcx>> {
1566 let mut result = Vec::new();
1567 for (i, &arg_ty) in arg_tys.iter().enumerate() {
1568 if i < arg_tys.len() - 1 {
1569 // Regular argument.
1570 let llarg = get_param(bcx.fcx.llfn, bcx.fcx.arg_pos(i) as c_uint);
1571 result.push(datum::Datum::new(llarg, arg_ty, arg_kind(bcx.fcx,
1576 // This is the last argument. Tuple it.
1578 ty::ty_tup(ref tupled_arg_tys) => {
1579 let tuple_args_scope_id = cleanup::CustomScope(arg_scope);
1582 datum::lvalue_scratch_datum(bcx,
1586 tuple_args_scope_id,
1591 for (j, &tupled_arg_ty) in
1592 tupled_arg_tys.iter().enumerate() {
1594 get_param(bcx.fcx.llfn,
1595 bcx.fcx.arg_pos(i + j) as c_uint);
1596 let lldest = GEPi(bcx, llval, &[0, j]);
1597 let datum = datum::Datum::new(
1600 arg_kind(bcx.fcx, tupled_arg_ty));
1601 bcx = datum.store_to(bcx, lldest);
1605 let tuple = unpack_datum!(bcx,
1606 tuple.to_expr_datum()
1607 .to_rvalue_datum(bcx,
1612 bcx.tcx().sess.bug("last argument of a function with \
1613 `rust-call` ABI isn't a tuple?!")
1622 fn copy_args_to_allocas<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1623 arg_scope: cleanup::CustomScopeIndex,
1624 bcx: Block<'blk, 'tcx>,
1626 arg_datums: Vec<RvalueDatum<'tcx>>)
1627 -> Block<'blk, 'tcx> {
1628 debug!("copy_args_to_allocas");
1630 let _icx = push_ctxt("copy_args_to_allocas");
1633 let arg_scope_id = cleanup::CustomScope(arg_scope);
1635 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
1636 // For certain mode/type combinations, the raw llarg values are passed
1637 // by value. However, within the fn body itself, we want to always
1638 // have all locals and arguments be by-ref so that we can cancel the
1639 // cleanup and for better interaction with LLVM's debug info. So, if
1640 // the argument would be passed by value, we store it into an alloca.
1641 // This alloca should be optimized away by LLVM's mem-to-reg pass in
1642 // the event it's not truly needed.
1644 bcx = _match::store_arg(bcx, &*args[i].pat, arg_datum, arg_scope_id);
1646 if fcx.ccx.sess().opts.debuginfo == FullDebugInfo {
1647 debuginfo::create_argument_metadata(bcx, &args[i]);
1654 fn copy_unboxed_closure_args_to_allocas<'blk, 'tcx>(
1655 mut bcx: Block<'blk, 'tcx>,
1656 arg_scope: cleanup::CustomScopeIndex,
1658 arg_datums: Vec<RvalueDatum<'tcx>>,
1659 monomorphized_arg_types: &[Ty<'tcx>])
1660 -> Block<'blk, 'tcx> {
1661 let _icx = push_ctxt("copy_unboxed_closure_args_to_allocas");
1662 let arg_scope_id = cleanup::CustomScope(arg_scope);
1664 assert_eq!(arg_datums.len(), 1);
1666 let arg_datum = arg_datums.into_iter().next().unwrap();
1668 // Untuple the rest of the arguments.
1671 arg_datum.to_lvalue_datum_in_scope(bcx,
1674 let untupled_arg_types = match monomorphized_arg_types[0].sty {
1675 ty::ty_tup(ref types) => types.as_slice(),
1677 bcx.tcx().sess.span_bug(args[0].pat.span,
1678 "first arg to `rust-call` ABI function \
1682 for j in range(0, args.len()) {
1683 let tuple_element_type = untupled_arg_types[j];
1684 let tuple_element_datum =
1685 tuple_datum.get_element(bcx,
1687 |llval| GEPi(bcx, llval, &[0, j]));
1688 let tuple_element_datum = tuple_element_datum.to_expr_datum();
1689 let tuple_element_datum =
1691 tuple_element_datum.to_rvalue_datum(bcx,
1693 bcx = _match::store_arg(bcx,
1695 tuple_element_datum,
1698 if bcx.fcx.ccx.sess().opts.debuginfo == FullDebugInfo {
1699 debuginfo::create_argument_metadata(bcx, &args[j]);
1706 // Ties up the llstaticallocas -> llloadenv -> lltop edges,
1707 // and builds the return block.
1708 pub fn finish_fn<'blk, 'tcx>(fcx: &'blk FunctionContext<'blk, 'tcx>,
1709 last_bcx: Block<'blk, 'tcx>,
1710 retty: ty::FnOutput<'tcx>) {
1711 let _icx = push_ctxt("finish_fn");
1713 let ret_cx = match fcx.llreturn.get() {
1715 if !last_bcx.terminated.get() {
1716 Br(last_bcx, llreturn);
1718 raw_block(fcx, false, llreturn)
1723 // This shouldn't need to recompute the return type,
1724 // as new_fn_ctxt did it already.
1725 let substd_retty = retty.subst(fcx.ccx.tcx(), fcx.param_substs);
1726 build_return_block(fcx, ret_cx, substd_retty);
1728 debuginfo::clear_source_location(fcx);
1732 // Builds the return block for a function.
1733 pub fn build_return_block<'blk, 'tcx>(fcx: &FunctionContext<'blk, 'tcx>,
1734 ret_cx: Block<'blk, 'tcx>,
1735 retty: ty::FnOutput<'tcx>) {
1736 if fcx.llretslotptr.get().is_none() ||
1737 (!fcx.needs_ret_allocas && fcx.caller_expects_out_pointer) {
1738 return RetVoid(ret_cx);
1741 let retslot = if fcx.needs_ret_allocas {
1742 Load(ret_cx, fcx.llretslotptr.get().unwrap())
1744 fcx.llretslotptr.get().unwrap()
1746 let retptr = Value(retslot);
1747 match retptr.get_dominating_store(ret_cx) {
1748 // If there's only a single store to the ret slot, we can directly return
1749 // the value that was stored and omit the store and the alloca
1751 let retval = s.get_operand(0).unwrap().get();
1752 s.erase_from_parent();
1754 if retptr.has_no_uses() {
1755 retptr.erase_from_parent();
1758 let retval = if retty == ty::FnConverging(ty::mk_bool()) {
1759 Trunc(ret_cx, retval, Type::i1(fcx.ccx))
1764 if fcx.caller_expects_out_pointer {
1765 if let ty::FnConverging(retty) = retty {
1766 store_ty(ret_cx, retval, get_param(fcx.llfn, 0), retty);
1773 // Otherwise, copy the return value to the ret slot
1774 None => match retty {
1775 ty::FnConverging(retty) => {
1776 if fcx.caller_expects_out_pointer {
1777 memcpy_ty(ret_cx, get_param(fcx.llfn, 0), retslot, retty);
1780 Ret(ret_cx, load_ty(ret_cx, retslot, retty))
1783 ty::FnDiverging => {
1784 if fcx.caller_expects_out_pointer {
1787 Ret(ret_cx, C_undef(Type::nil(fcx.ccx)))
1794 #[deriving(Clone, Copy, Eq, PartialEq)]
1795 pub enum IsUnboxedClosureFlag {
1800 // trans_closure: Builds an LLVM function out of a source function.
1801 // If the function closes over its environment a closure will be
1803 pub fn trans_closure<'a, 'b, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1807 param_substs: &Substs<'tcx>,
1808 fn_ast_id: ast::NodeId,
1809 _attributes: &[ast::Attribute],
1810 output_type: ty::FnOutput<'tcx>,
1812 closure_env: closure::ClosureEnv<'b, 'tcx>) {
1813 ccx.stats().n_closures.set(ccx.stats().n_closures.get() + 1);
1815 let _icx = push_ctxt("trans_closure");
1816 set_uwtable(llfndecl);
1818 debug!("trans_closure(..., param_substs={})",
1819 param_substs.repr(ccx.tcx()));
1821 let arena = TypedArena::new();
1822 let fcx = new_fn_ctxt(ccx,
1825 closure_env.kind != closure::NotClosure,
1830 let mut bcx = init_function(&fcx, false, output_type);
1832 // cleanup scope for the incoming arguments
1833 let fn_cleanup_debug_loc =
1834 debuginfo::get_cleanup_debug_loc_for_ast_node(ccx, fn_ast_id, body.span, true);
1835 let arg_scope = fcx.push_custom_cleanup_scope_with_debug_loc(fn_cleanup_debug_loc);
1837 let block_ty = node_id_type(bcx, body.id);
1839 // Set up arguments to the function.
1840 let monomorphized_arg_types =
1842 .map(|arg| node_id_type(bcx, arg.id))
1843 .collect::<Vec<_>>();
1844 let monomorphized_arg_types = match closure_env.kind {
1845 closure::NotClosure | closure::BoxedClosure(..) => {
1846 monomorphized_arg_types
1849 // Tuple up closure argument types for the "rust-call" ABI.
1850 closure::UnboxedClosure(..) => {
1851 vec![ty::mk_tup(ccx.tcx(), monomorphized_arg_types)]
1854 for monomorphized_arg_type in monomorphized_arg_types.iter() {
1855 debug!("trans_closure: monomorphized_arg_type: {}",
1856 ty_to_string(ccx.tcx(), *monomorphized_arg_type));
1858 debug!("trans_closure: function lltype: {}",
1859 bcx.fcx.ccx.tn().val_to_string(bcx.fcx.llfn));
1861 let arg_datums = if abi != RustCall {
1862 create_datums_for_fn_args(&fcx,
1863 monomorphized_arg_types.as_slice())
1865 create_datums_for_fn_args_under_call_abi(
1868 monomorphized_arg_types.as_slice())
1871 bcx = match closure_env.kind {
1872 closure::NotClosure | closure::BoxedClosure(..) => {
1873 copy_args_to_allocas(&fcx,
1876 decl.inputs.as_slice(),
1879 closure::UnboxedClosure(..) => {
1880 copy_unboxed_closure_args_to_allocas(
1883 decl.inputs.as_slice(),
1885 monomorphized_arg_types.as_slice())
1889 bcx = closure_env.load(bcx, cleanup::CustomScope(arg_scope));
1891 // Up until here, IR instructions for this function have explicitly not been annotated with
1892 // source code location, so we don't step into call setup code. From here on, source location
1893 // emitting should be enabled.
1894 debuginfo::start_emitting_source_locations(&fcx);
1896 let dest = match fcx.llretslotptr.get() {
1897 Some(_) => expr::SaveIn(fcx.get_ret_slot(bcx, ty::FnConverging(block_ty), "iret_slot")),
1899 assert!(type_is_zero_size(bcx.ccx(), block_ty));
1904 // This call to trans_block is the place where we bridge between
1905 // translation calls that don't have a return value (trans_crate,
1906 // trans_mod, trans_item, et cetera) and those that do
1907 // (trans_block, trans_expr, et cetera).
1908 bcx = controlflow::trans_block(bcx, body, dest);
1911 expr::SaveIn(slot) if fcx.needs_ret_allocas => {
1912 Store(bcx, slot, fcx.llretslotptr.get().unwrap());
1917 match fcx.llreturn.get() {
1919 Br(bcx, fcx.return_exit_block());
1920 fcx.pop_custom_cleanup_scope(arg_scope);
1923 // Microoptimization writ large: avoid creating a separate
1924 // llreturn basic block
1925 bcx = fcx.pop_and_trans_custom_cleanup_scope(bcx, arg_scope);
1929 // Put return block after all other blocks.
1930 // This somewhat improves single-stepping experience in debugger.
1932 let llreturn = fcx.llreturn.get();
1933 for &llreturn in llreturn.iter() {
1934 llvm::LLVMMoveBasicBlockAfter(llreturn, bcx.llbb);
1938 // Insert the mandatory first few basic blocks before lltop.
1939 finish_fn(&fcx, bcx, output_type);
1942 // trans_fn: creates an LLVM function corresponding to a source language
1944 pub fn trans_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1948 param_substs: &Substs<'tcx>,
1950 attrs: &[ast::Attribute]) {
1951 let _s = StatRecorder::new(ccx, ccx.tcx().map.path_to_string(id).to_string());
1952 debug!("trans_fn(param_substs={})", param_substs.repr(ccx.tcx()));
1953 let _icx = push_ctxt("trans_fn");
1954 let fn_ty = ty::node_id_to_type(ccx.tcx(), id);
1955 let output_type = ty::ty_fn_ret(fn_ty);
1956 let abi = ty::ty_fn_abi(fn_ty);
1966 closure::ClosureEnv::new(&[], closure::NotClosure));
1969 pub fn trans_enum_variant<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
1970 _enum_id: ast::NodeId,
1971 variant: &ast::Variant,
1972 _args: &[ast::VariantArg],
1974 param_substs: &Substs<'tcx>,
1975 llfndecl: ValueRef) {
1976 let _icx = push_ctxt("trans_enum_variant");
1978 trans_enum_variant_or_tuple_like_struct(
1986 pub fn trans_named_tuple_constructor<'blk, 'tcx>(mut bcx: Block<'blk, 'tcx>,
1989 args: callee::CallArgs,
1991 call_info: Option<NodeInfo>)
1992 -> Result<'blk, 'tcx> {
1994 let ccx = bcx.fcx.ccx;
1995 let tcx = ccx.tcx();
1997 let result_ty = match ctor_ty.sty {
1998 ty::ty_bare_fn(ref bft) => bft.sig.0.output.unwrap(),
1999 _ => ccx.sess().bug(
2000 format!("trans_enum_variant_constructor: \
2001 unexpected ctor return type {}",
2002 ctor_ty.repr(tcx)).as_slice())
2005 // Get location to store the result. If the user does not care about
2006 // the result, just make a stack slot
2007 let llresult = match dest {
2008 expr::SaveIn(d) => d,
2010 if !type_is_zero_size(ccx, result_ty) {
2011 alloc_ty(bcx, result_ty, "constructor_result")
2013 C_undef(type_of::type_of(ccx, result_ty))
2018 if !type_is_zero_size(ccx, result_ty) {
2020 callee::ArgExprs(exprs) => {
2021 let fields = exprs.iter().map(|x| &**x).enumerate().collect::<Vec<_>>();
2022 bcx = expr::trans_adt(bcx,
2027 expr::SaveIn(llresult),
2030 _ => ccx.sess().bug("expected expr as arguments for variant/struct tuple constructor")
2034 // If the caller doesn't care about the result
2035 // drop the temporary we made
2036 let bcx = match dest {
2037 expr::SaveIn(_) => bcx,
2039 glue::drop_ty(bcx, llresult, result_ty, call_info)
2043 Result::new(bcx, llresult)
2046 pub fn trans_tuple_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2047 _fields: &[ast::StructField],
2048 ctor_id: ast::NodeId,
2049 param_substs: &Substs<'tcx>,
2050 llfndecl: ValueRef) {
2051 let _icx = push_ctxt("trans_tuple_struct");
2053 trans_enum_variant_or_tuple_like_struct(
2061 fn trans_enum_variant_or_tuple_like_struct<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2062 ctor_id: ast::NodeId,
2064 param_substs: &Substs<'tcx>,
2065 llfndecl: ValueRef) {
2066 let ctor_ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2067 let ctor_ty = ctor_ty.subst(ccx.tcx(), param_substs);
2069 let result_ty = match ctor_ty.sty {
2070 ty::ty_bare_fn(ref bft) => bft.sig.0.output,
2071 _ => ccx.sess().bug(
2072 format!("trans_enum_variant_or_tuple_like_struct: \
2073 unexpected ctor return type {}",
2074 ty_to_string(ccx.tcx(), ctor_ty)).as_slice())
2077 let arena = TypedArena::new();
2078 let fcx = new_fn_ctxt(ccx, llfndecl, ctor_id, false, result_ty,
2079 param_substs, None, &arena);
2080 let bcx = init_function(&fcx, false, result_ty);
2082 assert!(!fcx.needs_ret_allocas);
2084 let arg_tys = ty::ty_fn_args(ctor_ty);
2086 let arg_datums = create_datums_for_fn_args(&fcx, arg_tys.as_slice());
2088 if !type_is_zero_size(fcx.ccx, result_ty.unwrap()) {
2089 let dest = fcx.get_ret_slot(bcx, result_ty, "eret_slot");
2090 let repr = adt::represent_type(ccx, result_ty.unwrap());
2091 for (i, arg_datum) in arg_datums.into_iter().enumerate() {
2092 let lldestptr = adt::trans_field_ptr(bcx,
2097 arg_datum.store_to(bcx, lldestptr);
2099 adt::trans_set_discr(bcx, &*repr, dest, disr);
2102 finish_fn(&fcx, bcx, result_ty);
2105 fn enum_variant_size_lint(ccx: &CrateContext, enum_def: &ast::EnumDef, sp: Span, id: ast::NodeId) {
2106 let mut sizes = Vec::new(); // does no allocation if no pushes, thankfully
2108 let levels = ccx.tcx().node_lint_levels.borrow();
2109 let lint_id = lint::LintId::of(lint::builtin::VARIANT_SIZE_DIFFERENCES);
2110 let lvlsrc = match levels.get(&(id, lint_id)) {
2111 None | Some(&(lint::Allow, _)) => return,
2112 Some(&lvlsrc) => lvlsrc,
2115 let avar = adt::represent_type(ccx, ty::node_id_to_type(ccx.tcx(), id));
2117 adt::General(_, ref variants, _) => {
2118 for var in variants.iter() {
2120 for field in var.fields.iter().skip(1) {
2121 // skip the discriminant
2122 size += llsize_of_real(ccx, sizing_type_of(ccx, *field));
2127 _ => { /* its size is either constant or unimportant */ }
2130 let (largest, slargest, largest_index) = sizes.iter().enumerate().fold((0, 0, 0),
2131 |(l, s, li), (idx, &size)|
2134 } else if size > s {
2141 // we only warn if the largest variant is at least thrice as large as
2142 // the second-largest.
2143 if largest > slargest * 3 && slargest > 0 {
2144 // Use lint::raw_emit_lint rather than sess.add_lint because the lint-printing
2145 // pass for the latter already ran.
2146 lint::raw_emit_lint(&ccx.tcx().sess, lint::builtin::VARIANT_SIZE_DIFFERENCES,
2148 format!("enum variant is more than three times larger \
2149 ({} bytes) than the next largest (ignoring padding)",
2150 largest).as_slice());
2152 ccx.sess().span_note(enum_def.variants[largest_index].span,
2153 "this variant is the largest");
2157 pub struct TransItemVisitor<'a, 'tcx: 'a> {
2158 pub ccx: &'a CrateContext<'a, 'tcx>,
2161 impl<'a, 'tcx, 'v> Visitor<'v> for TransItemVisitor<'a, 'tcx> {
2162 fn visit_item(&mut self, i: &ast::Item) {
2163 trans_item(self.ccx, i);
2167 pub fn llvm_linkage_by_name(name: &str) -> Option<Linkage> {
2168 // Use the names from src/llvm/docs/LangRef.rst here. Most types are only
2169 // applicable to variable declarations and may not really make sense for
2170 // Rust code in the first place but whitelist them anyway and trust that
2171 // the user knows what s/he's doing. Who knows, unanticipated use cases
2172 // may pop up in the future.
2174 // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported
2175 // and don't have to be, LLVM treats them as no-ops.
2177 "appending" => Some(llvm::AppendingLinkage),
2178 "available_externally" => Some(llvm::AvailableExternallyLinkage),
2179 "common" => Some(llvm::CommonLinkage),
2180 "extern_weak" => Some(llvm::ExternalWeakLinkage),
2181 "external" => Some(llvm::ExternalLinkage),
2182 "internal" => Some(llvm::InternalLinkage),
2183 "linkonce" => Some(llvm::LinkOnceAnyLinkage),
2184 "linkonce_odr" => Some(llvm::LinkOnceODRLinkage),
2185 "private" => Some(llvm::PrivateLinkage),
2186 "weak" => Some(llvm::WeakAnyLinkage),
2187 "weak_odr" => Some(llvm::WeakODRLinkage),
2193 /// Enum describing the origin of an LLVM `Value`, for linkage purposes.
2195 pub enum ValueOrigin {
2196 /// The LLVM `Value` is in this context because the corresponding item was
2197 /// assigned to the current compilation unit.
2198 OriginalTranslation,
2199 /// The `Value`'s corresponding item was assigned to some other compilation
2200 /// unit, but the `Value` was translated in this context anyway because the
2201 /// item is marked `#[inline]`.
2205 /// Set the appropriate linkage for an LLVM `ValueRef` (function or global).
2206 /// If the `llval` is the direct translation of a specific Rust item, `id`
2207 /// should be set to the `NodeId` of that item. (This mapping should be
2208 /// 1-to-1, so monomorphizations and drop/visit glue should have `id` set to
2209 /// `None`.) `llval_origin` indicates whether `llval` is the translation of an
2210 /// item assigned to `ccx`'s compilation unit or an inlined copy of an item
2211 /// assigned to a different compilation unit.
2212 pub fn update_linkage(ccx: &CrateContext,
2214 id: Option<ast::NodeId>,
2215 llval_origin: ValueOrigin) {
2216 match llval_origin {
2218 // `llval` is a translation of an item defined in a separate
2219 // compilation unit. This only makes sense if there are at least
2220 // two compilation units.
2221 assert!(ccx.sess().opts.cg.codegen_units > 1);
2222 // `llval` is a copy of something defined elsewhere, so use
2223 // `AvailableExternallyLinkage` to avoid duplicating code in the
2225 llvm::SetLinkage(llval, llvm::AvailableExternallyLinkage);
2228 OriginalTranslation => {},
2231 if let Some(id) = id {
2232 let item = ccx.tcx().map.get(id);
2233 if let ast_map::NodeItem(i) = item {
2234 if let Some(name) = attr::first_attr_value_str_by_name(i.attrs[], "linkage") {
2235 if let Some(linkage) = llvm_linkage_by_name(name.get()) {
2236 llvm::SetLinkage(llval, linkage);
2238 ccx.sess().span_fatal(i.span, "invalid linkage specified");
2246 Some(id) if ccx.reachable().contains(&id) => {
2247 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2250 // `id` does not refer to an item in `ccx.reachable`.
2251 if ccx.sess().opts.cg.codegen_units > 1 {
2252 llvm::SetLinkage(llval, llvm::ExternalLinkage);
2254 llvm::SetLinkage(llval, llvm::InternalLinkage);
2260 pub fn trans_item(ccx: &CrateContext, item: &ast::Item) {
2261 let _icx = push_ctxt("trans_item");
2263 let from_external = ccx.external_srcs().borrow().contains_key(&item.id);
2266 ast::ItemFn(ref decl, _fn_style, abi, ref generics, ref body) => {
2267 if !generics.is_type_parameterized() {
2268 let trans_everywhere = attr::requests_inline(item.attrs.as_slice());
2269 // Ignore `trans_everywhere` for cross-crate inlined items
2270 // (`from_external`). `trans_item` will be called once for each
2271 // compilation unit that references the item, so it will still get
2272 // translated everywhere it's needed.
2273 for (ref ccx, is_origin) in ccx.maybe_iter(!from_external && trans_everywhere) {
2274 let llfn = get_item_val(ccx, item.id);
2276 foreign::trans_rust_fn_with_foreign_abi(ccx,
2279 item.attrs.as_slice(),
2281 &Substs::trans_empty(),
2289 &Substs::trans_empty(),
2291 item.attrs.as_slice());
2296 if is_origin { OriginalTranslation } else { InlinedCopy });
2300 // Be sure to travel more than just one layer deep to catch nested
2301 // items in blocks and such.
2302 let mut v = TransItemVisitor{ ccx: ccx };
2303 v.visit_block(&**body);
2305 ast::ItemImpl(_, ref generics, _, _, ref impl_items) => {
2306 meth::trans_impl(ccx,
2308 impl_items.as_slice(),
2312 ast::ItemMod(ref m) => {
2313 trans_mod(&ccx.rotate(), m);
2315 ast::ItemEnum(ref enum_definition, _) => {
2316 enum_variant_size_lint(ccx, enum_definition, item.span, item.id);
2318 ast::ItemConst(_, ref expr) => {
2319 // Recurse on the expression to catch items in blocks
2320 let mut v = TransItemVisitor{ ccx: ccx };
2321 v.visit_expr(&**expr);
2323 ast::ItemStatic(_, m, ref expr) => {
2324 // Recurse on the expression to catch items in blocks
2325 let mut v = TransItemVisitor{ ccx: ccx };
2326 v.visit_expr(&**expr);
2328 consts::trans_static(ccx, m, item.id);
2329 let g = get_item_val(ccx, item.id);
2330 update_linkage(ccx, g, Some(item.id), OriginalTranslation);
2332 // Do static_assert checking. It can't really be done much earlier
2333 // because we need to get the value of the bool out of LLVM
2334 if attr::contains_name(item.attrs.as_slice(), "static_assert") {
2335 if m == ast::MutMutable {
2336 ccx.sess().span_fatal(expr.span,
2337 "cannot have static_assert on a mutable \
2341 let v = ccx.static_values().borrow()[item.id].clone();
2343 if !(llvm::LLVMConstIntGetZExtValue(v) != 0) {
2344 ccx.sess().span_fatal(expr.span, "static assertion failed");
2349 ast::ItemForeignMod(ref foreign_mod) => {
2350 foreign::trans_foreign_mod(ccx, foreign_mod);
2352 ast::ItemTrait(..) => {
2353 // Inside of this trait definition, we won't be actually translating any
2354 // functions, but the trait still needs to be walked. Otherwise default
2355 // methods with items will not get translated and will cause ICE's when
2356 // metadata time comes around.
2357 let mut v = TransItemVisitor{ ccx: ccx };
2358 visit::walk_item(&mut v, item);
2360 _ => {/* fall through */ }
2364 // Translate a module. Doing this amounts to translating the items in the
2365 // module; there ends up being no artifact (aside from linkage names) of
2366 // separate modules in the compiled program. That's because modules exist
2367 // only as a convenience for humans working with the code, to organize names
2368 // and control visibility.
2369 pub fn trans_mod(ccx: &CrateContext, m: &ast::Mod) {
2370 let _icx = push_ctxt("trans_mod");
2371 for item in m.items.iter() {
2372 trans_item(ccx, &**item);
2376 fn finish_register_fn(ccx: &CrateContext, sp: Span, sym: String, node_id: ast::NodeId,
2378 ccx.item_symbols().borrow_mut().insert(node_id, sym);
2380 // The stack exhaustion lang item shouldn't have a split stack because
2381 // otherwise it would continue to be exhausted (bad), and both it and the
2382 // eh_personality functions need to be externally linkable.
2383 let def = ast_util::local_def(node_id);
2384 if ccx.tcx().lang_items.stack_exhausted() == Some(def) {
2385 unset_split_stack(llfn);
2386 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2388 if ccx.tcx().lang_items.eh_personality() == Some(def) {
2389 llvm::SetLinkage(llfn, llvm::ExternalLinkage);
2393 if is_entry_fn(ccx.sess(), node_id) {
2394 create_entry_wrapper(ccx, sp, llfn);
2398 fn register_fn<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>,
2401 node_id: ast::NodeId,
2402 node_type: Ty<'tcx>)
2404 match node_type.sty {
2405 ty::ty_bare_fn(ref f) => {
2406 assert!(f.abi == Rust || f.abi == RustCall);
2408 _ => panic!("expected bare rust fn")
2411 let llfn = decl_rust_fn(ccx, node_type, sym.as_slice());
2412 finish_register_fn(ccx, sp, sym, node_id, llfn);
2416 pub fn get_fn_llvm_attributes<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, fn_ty: Ty<'tcx>)
2417 -> llvm::AttrBuilder {
2418 use middle::ty::{BrAnon, ReLateBound};
2420 let (fn_sig, abi, has_env) = match fn_ty.sty {
2421 ty::ty_closure(ref f) => (f.sig.clone(), f.abi, true),
2422 ty::ty_bare_fn(ref f) => (f.sig.clone(), f.abi, false),
2423 ty::ty_unboxed_closure(closure_did, _, ref substs) => {
2424 let unboxed_closures = ccx.tcx().unboxed_closures.borrow();
2425 let ref function_type = (*unboxed_closures)[closure_did]
2428 (function_type.sig.subst(ccx.tcx(), substs), RustCall, true)
2430 _ => ccx.sess().bug("expected closure or function.")
2434 // Since index 0 is the return value of the llvm func, we start
2435 // at either 1 or 2 depending on whether there's an env slot or not
2436 let mut first_arg_offset = if has_env { 2 } else { 1 };
2437 let mut attrs = llvm::AttrBuilder::new();
2438 let ret_ty = fn_sig.0.output;
2440 // These have an odd calling convention, so we need to manually
2441 // unpack the input ty's
2442 let input_tys = match fn_ty.sty {
2443 ty::ty_unboxed_closure(_, _, _) => {
2444 assert!(abi == RustCall);
2446 match fn_sig.0.inputs[0].sty {
2447 ty::ty_tup(ref inputs) => inputs.clone(),
2448 _ => ccx.sess().bug("expected tuple'd inputs")
2451 ty::ty_bare_fn(_) if abi == RustCall => {
2452 let mut inputs = vec![fn_sig.0.inputs[0]];
2454 match fn_sig.0.inputs[1].sty {
2455 ty::ty_tup(ref t_in) => {
2456 inputs.push_all(t_in.as_slice());
2459 _ => ccx.sess().bug("expected tuple'd inputs")
2462 _ => fn_sig.0.inputs.clone()
2465 if let ty::FnConverging(ret_ty) = ret_ty {
2466 // A function pointer is called without the declaration
2467 // available, so we have to apply any attributes with ABI
2468 // implications directly to the call instruction. Right now,
2469 // the only attribute we need to worry about is `sret`.
2470 if type_of::return_uses_outptr(ccx, ret_ty) {
2471 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, ret_ty));
2473 // The outptr can be noalias and nocapture because it's entirely
2474 // invisible to the program. We also know it's nonnull as well
2475 // as how many bytes we can dereference
2476 attrs.arg(1, llvm::StructRetAttribute)
2477 .arg(1, llvm::NoAliasAttribute)
2478 .arg(1, llvm::NoCaptureAttribute)
2479 .arg(1, llvm::DereferenceableAttribute(llret_sz));
2481 // Add one more since there's an outptr
2482 first_arg_offset += 1;
2484 // The `noalias` attribute on the return value is useful to a
2485 // function ptr caller.
2487 // `~` pointer return values never alias because ownership
2489 ty::ty_uniq(it) if !ty::type_is_sized(ccx.tcx(), it) => {}
2491 attrs.ret(llvm::NoAliasAttribute);
2496 // We can also mark the return value as `dereferenceable` in certain cases
2498 // These are not really pointers but pairs, (pointer, len)
2500 ty::ty_rptr(_, ty::mt { ty: it, .. }) if !ty::type_is_sized(ccx.tcx(), it) => {}
2501 ty::ty_uniq(inner) | ty::ty_rptr(_, ty::mt { ty: inner, .. }) => {
2502 let llret_sz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2503 attrs.ret(llvm::DereferenceableAttribute(llret_sz));
2508 if let ty::ty_bool = ret_ty.sty {
2509 attrs.ret(llvm::ZExtAttribute);
2514 for (idx, &t) in input_tys.iter().enumerate().map(|(i, v)| (i + first_arg_offset, v)) {
2516 // this needs to be first to prevent fat pointers from falling through
2517 _ if !type_is_immediate(ccx, t) => {
2518 let llarg_sz = llsize_of_real(ccx, type_of::type_of(ccx, t));
2520 // For non-immediate arguments the callee gets its own copy of
2521 // the value on the stack, so there are no aliases. It's also
2522 // program-invisible so can't possibly capture
2523 attrs.arg(idx, llvm::NoAliasAttribute)
2524 .arg(idx, llvm::NoCaptureAttribute)
2525 .arg(idx, llvm::DereferenceableAttribute(llarg_sz));
2529 attrs.arg(idx, llvm::ZExtAttribute);
2532 // `~` pointer parameters never alias because ownership is transferred
2533 ty::ty_uniq(inner) => {
2534 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, inner));
2536 attrs.arg(idx, llvm::NoAliasAttribute)
2537 .arg(idx, llvm::DereferenceableAttribute(llsz));
2540 // `&mut` pointer parameters never alias other parameters, or mutable global data
2542 // `&T` where `T` contains no `UnsafeCell<U>` is immutable, and can be marked as both
2543 // `readonly` and `noalias`, as LLVM's definition of `noalias` is based solely on
2544 // memory dependencies rather than pointer equality
2545 ty::ty_rptr(b, mt) if mt.mutbl == ast::MutMutable ||
2546 !ty::type_contents(ccx.tcx(), mt.ty).interior_unsafe() => {
2548 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2549 attrs.arg(idx, llvm::NoAliasAttribute)
2550 .arg(idx, llvm::DereferenceableAttribute(llsz));
2552 if mt.mutbl == ast::MutImmutable {
2553 attrs.arg(idx, llvm::ReadOnlyAttribute);
2556 if let ReLateBound(_, BrAnon(_)) = b {
2557 attrs.arg(idx, llvm::NoCaptureAttribute);
2561 // When a reference in an argument has no named lifetime, it's impossible for that
2562 // reference to escape this function (returned or stored beyond the call by a closure).
2563 ty::ty_rptr(ReLateBound(_, BrAnon(_)), mt) => {
2564 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2565 attrs.arg(idx, llvm::NoCaptureAttribute)
2566 .arg(idx, llvm::DereferenceableAttribute(llsz));
2569 // & pointer parameters are also never null and we know exactly how
2570 // many bytes we can dereference
2571 ty::ty_rptr(_, mt) => {
2572 let llsz = llsize_of_real(ccx, type_of::type_of(ccx, mt.ty));
2573 attrs.arg(idx, llvm::DereferenceableAttribute(llsz));
2582 // only use this for foreign function ABIs and glue, use `register_fn` for Rust functions
2583 pub fn register_fn_llvmty(ccx: &CrateContext,
2586 node_id: ast::NodeId,
2588 llfty: Type) -> ValueRef {
2589 debug!("register_fn_llvmty id={} sym={}", node_id, sym);
2591 let llfn = decl_fn(ccx, sym.as_slice(), cc, llfty, ty::FnConverging(ty::mk_nil(ccx.tcx())));
2592 finish_register_fn(ccx, sp, sym, node_id, llfn);
2596 pub fn is_entry_fn(sess: &Session, node_id: ast::NodeId) -> bool {
2597 match *sess.entry_fn.borrow() {
2598 Some((entry_id, _)) => node_id == entry_id,
2603 // Create a _rust_main(args: ~[str]) function which will be called from the
2604 // runtime rust_start function
2605 pub fn create_entry_wrapper(ccx: &CrateContext,
2607 main_llfn: ValueRef) {
2608 let et = ccx.sess().entry_type.get().unwrap();
2610 config::EntryMain => {
2611 create_entry_fn(ccx, main_llfn, true);
2613 config::EntryStart => create_entry_fn(ccx, main_llfn, false),
2614 config::EntryNone => {} // Do nothing.
2617 fn create_entry_fn(ccx: &CrateContext,
2618 rust_main: ValueRef,
2619 use_start_lang_item: bool) {
2620 let llfty = Type::func(&[ccx.int_type(), Type::i8p(ccx).ptr_to()],
2623 let llfn = decl_cdecl_fn(ccx, "main", llfty, ty::mk_nil(ccx.tcx()));
2625 // FIXME: #16581: Marking a symbol in the executable with `dllexport`
2626 // linkage forces MinGW's linker to output a `.reloc` section for ASLR
2627 if ccx.sess().target.target.options.is_like_windows {
2628 unsafe { llvm::LLVMRustSetDLLExportStorageClass(llfn) }
2631 let llbb = "top".with_c_str(|buf| {
2633 llvm::LLVMAppendBasicBlockInContext(ccx.llcx(), llfn, buf)
2636 let bld = ccx.raw_builder();
2638 llvm::LLVMPositionBuilderAtEnd(bld, llbb);
2640 let (start_fn, args) = if use_start_lang_item {
2641 let start_def_id = match ccx.tcx().lang_items.require(StartFnLangItem) {
2643 Err(s) => { ccx.sess().fatal(s.as_slice()); }
2645 let start_fn = if start_def_id.krate == ast::LOCAL_CRATE {
2646 get_item_val(ccx, start_def_id.node)
2648 let start_fn_type = csearch::get_type(ccx.tcx(),
2650 trans_external_path(ccx, start_def_id, start_fn_type)
2654 let opaque_rust_main = "rust_main".with_c_str(|buf| {
2655 llvm::LLVMBuildPointerCast(bld, rust_main, Type::i8p(ccx).to_ref(), buf)
2666 debug!("using user-defined start fn");
2668 get_param(llfn, 0 as c_uint),
2669 get_param(llfn, 1 as c_uint)
2675 let result = llvm::LLVMBuildCall(bld,
2678 args.len() as c_uint,
2681 llvm::LLVMBuildRet(bld, result);
2686 fn exported_name<'a, 'tcx>(ccx: &CrateContext<'a, 'tcx>, id: ast::NodeId,
2687 ty: Ty<'tcx>, attrs: &[ast::Attribute]) -> String {
2688 match ccx.external_srcs().borrow().get(&id) {
2690 let sym = csearch::get_symbol(&ccx.sess().cstore, did);
2691 debug!("found item {} in other crate...", sym);
2697 match attr::first_attr_value_str_by_name(attrs, "export_name") {
2698 // Use provided name
2699 Some(name) => name.get().to_string(),
2701 _ => ccx.tcx().map.with_path(id, |path| {
2702 if attr::contains_name(attrs, "no_mangle") {
2704 path.last().unwrap().to_string()
2706 match weak_lang_items::link_name(attrs) {
2707 Some(name) => name.get().to_string(),
2709 // Usual name mangling
2710 mangle_exported_name(ccx, path, ty, id)
2718 fn contains_null(s: &str) -> bool {
2719 s.bytes().any(|b| b == 0)
2722 pub fn get_item_val(ccx: &CrateContext, id: ast::NodeId) -> ValueRef {
2723 debug!("get_item_val(id=`{}`)", id);
2725 match ccx.item_vals().borrow().get(&id).cloned() {
2726 Some(v) => return v,
2730 let item = ccx.tcx().map.get(id);
2731 let val = match item {
2732 ast_map::NodeItem(i) => {
2733 let ty = ty::node_id_to_type(ccx.tcx(), i.id);
2734 let sym = || exported_name(ccx, id, ty, i.attrs.as_slice());
2736 let v = match i.node {
2737 ast::ItemStatic(_, _, ref expr) => {
2738 // If this static came from an external crate, then
2739 // we need to get the symbol from csearch instead of
2740 // using the current crate's name/version
2741 // information in the hash of the symbol
2743 debug!("making {}", sym);
2745 // We need the translated value here, because for enums the
2746 // LLVM type is not fully determined by the Rust type.
2747 let (v, ty) = consts::const_expr(ccx, &**expr);
2748 ccx.static_values().borrow_mut().insert(id, v);
2750 // boolean SSA values are i1, but they have to be stored in i8 slots,
2751 // otherwise some LLVM optimization passes don't work as expected
2752 let llty = if ty::type_is_bool(ty) {
2753 llvm::LLVMInt8TypeInContext(ccx.llcx())
2757 if contains_null(sym.as_slice()) {
2759 format!("Illegal null byte in export_name \
2760 value: `{}`", sym).as_slice());
2762 let g = sym.with_c_str(|buf| {
2763 llvm::LLVMAddGlobal(ccx.llmod(), llty, buf)
2766 if attr::contains_name(i.attrs.as_slice(),
2768 llvm::set_thread_local(g, true);
2770 ccx.item_symbols().borrow_mut().insert(i.id, sym);
2775 ast::ItemConst(_, ref expr) => {
2776 let (v, _) = consts::const_expr(ccx, &**expr);
2777 ccx.const_values().borrow_mut().insert(id, v);
2781 ast::ItemFn(_, _, abi, _, _) => {
2783 let llfn = if abi == Rust {
2784 register_fn(ccx, i.span, sym, i.id, ty)
2786 foreign::register_rust_fn_with_foreign_abi(ccx,
2791 set_llvm_fn_attrs(ccx, i.attrs.as_slice(), llfn);
2795 _ => panic!("get_item_val: weird result in table")
2798 match attr::first_attr_value_str_by_name(i.attrs.as_slice(),
2801 if contains_null(sect.get()) {
2802 ccx.sess().fatal(format!("Illegal null byte in link_section value: `{}`",
2803 sect.get()).as_slice());
2806 sect.get().with_c_str(|buf| {
2807 llvm::LLVMSetSection(v, buf);
2817 ast_map::NodeTraitItem(trait_method) => {
2818 debug!("get_item_val(): processing a NodeTraitItem");
2819 match *trait_method {
2820 ast::RequiredMethod(_) | ast::TypeTraitItem(_) => {
2821 ccx.sess().bug("unexpected variant: required trait \
2822 method in get_item_val()");
2824 ast::ProvidedMethod(ref m) => {
2825 register_method(ccx, id, &**m)
2830 ast_map::NodeImplItem(ii) => {
2832 ast::MethodImplItem(ref m) => register_method(ccx, id, &**m),
2833 ast::TypeImplItem(ref typedef) => {
2834 ccx.sess().span_bug(typedef.span,
2835 "unexpected variant: required impl \
2836 method in get_item_val()")
2841 ast_map::NodeForeignItem(ni) => {
2843 ast::ForeignItemFn(..) => {
2844 let abi = ccx.tcx().map.get_foreign_abi(id);
2845 let ty = ty::node_id_to_type(ccx.tcx(), ni.id);
2846 let name = foreign::link_name(&*ni);
2847 foreign::register_foreign_item_fn(ccx, abi, ty, name.get().as_slice())
2849 ast::ForeignItemStatic(..) => {
2850 foreign::register_static(ccx, &*ni)
2855 ast_map::NodeVariant(ref v) => {
2857 let args = match v.node.kind {
2858 ast::TupleVariantKind(ref args) => args,
2859 ast::StructVariantKind(_) => {
2860 panic!("struct variant kind unexpected in get_item_val")
2863 assert!(args.len() != 0u);
2864 let ty = ty::node_id_to_type(ccx.tcx(), id);
2865 let parent = ccx.tcx().map.get_parent(id);
2866 let enm = ccx.tcx().map.expect_item(parent);
2867 let sym = exported_name(ccx,
2870 enm.attrs.as_slice());
2872 llfn = match enm.node {
2873 ast::ItemEnum(_, _) => {
2874 register_fn(ccx, (*v).span, sym, id, ty)
2876 _ => panic!("NodeVariant, shouldn't happen")
2878 set_inline_hint(llfn);
2882 ast_map::NodeStructCtor(struct_def) => {
2883 // Only register the constructor if this is a tuple-like struct.
2884 let ctor_id = match struct_def.ctor_id {
2886 ccx.sess().bug("attempt to register a constructor of \
2887 a non-tuple-like struct")
2889 Some(ctor_id) => ctor_id,
2891 let parent = ccx.tcx().map.get_parent(id);
2892 let struct_item = ccx.tcx().map.expect_item(parent);
2893 let ty = ty::node_id_to_type(ccx.tcx(), ctor_id);
2894 let sym = exported_name(ccx,
2899 let llfn = register_fn(ccx, struct_item.span,
2901 set_inline_hint(llfn);
2906 ccx.sess().bug(format!("get_item_val(): unexpected variant: {}",
2907 variant).as_slice())
2911 // All LLVM globals and functions are initially created as external-linkage
2912 // declarations. If `trans_item`/`trans_fn` later turns the declaration
2913 // into a definition, it adjusts the linkage then (using `update_linkage`).
2915 // The exception is foreign items, which have their linkage set inside the
2916 // call to `foreign::register_*` above. We don't touch the linkage after
2917 // that (`foreign::trans_foreign_mod` doesn't adjust the linkage like the
2918 // other item translation functions do).
2920 ccx.item_vals().borrow_mut().insert(id, val);
2924 fn register_method(ccx: &CrateContext, id: ast::NodeId,
2925 m: &ast::Method) -> ValueRef {
2926 let mty = ty::node_id_to_type(ccx.tcx(), id);
2928 let sym = exported_name(ccx, id, mty, m.attrs.as_slice());
2930 let llfn = register_fn(ccx, m.span, sym, id, mty);
2931 set_llvm_fn_attrs(ccx, m.attrs.as_slice(), llfn);
2935 pub fn crate_ctxt_to_encode_parms<'a, 'tcx>(cx: &'a SharedCrateContext<'tcx>,
2936 ie: encoder::EncodeInlinedItem<'a>)
2937 -> encoder::EncodeParams<'a, 'tcx> {
2938 encoder::EncodeParams {
2939 diag: cx.sess().diagnostic(),
2941 reexports: cx.export_map(),
2942 item_symbols: cx.item_symbols(),
2943 link_meta: cx.link_meta(),
2944 cstore: &cx.sess().cstore,
2945 encode_inlined_item: ie,
2946 reachable: cx.reachable(),
2950 pub fn write_metadata(cx: &SharedCrateContext, krate: &ast::Crate) -> Vec<u8> {
2953 let any_library = cx.sess().crate_types.borrow().iter().any(|ty| {
2954 *ty != config::CrateTypeExecutable
2960 let encode_inlined_item: encoder::EncodeInlinedItem =
2961 |ecx, rbml_w, ii| astencode::encode_inlined_item(ecx, rbml_w, ii);
2963 let encode_parms = crate_ctxt_to_encode_parms(cx, encode_inlined_item);
2964 let metadata = encoder::encode_metadata(encode_parms, krate);
2965 let mut compressed = encoder::metadata_encoding_version.to_vec();
2966 compressed.push_all(match flate::deflate_bytes(metadata.as_slice()) {
2967 Some(compressed) => compressed,
2968 None => cx.sess().fatal("failed to compress metadata"),
2970 let llmeta = C_bytes_in_context(cx.metadata_llcx(), compressed.as_slice());
2971 let llconst = C_struct_in_context(cx.metadata_llcx(), &[llmeta], false);
2972 let name = format!("rust_metadata_{}_{}",
2973 cx.link_meta().crate_name,
2974 cx.link_meta().crate_hash);
2975 let llglobal = name.with_c_str(|buf| {
2977 llvm::LLVMAddGlobal(cx.metadata_llmod(), val_ty(llconst).to_ref(), buf)
2981 llvm::LLVMSetInitializer(llglobal, llconst);
2982 let name = loader::meta_section_name(cx.sess().target.target.options.is_like_osx);
2983 name.with_c_str(|buf| {
2984 llvm::LLVMSetSection(llglobal, buf)
2990 /// Find any symbols that are defined in one compilation unit, but not declared
2991 /// in any other compilation unit. Give these symbols internal linkage.
2992 fn internalize_symbols(cx: &SharedCrateContext, reachable: &HashSet<String>) {
2993 use std::c_str::CString;
2996 let mut declared = HashSet::new();
2998 let iter_globals = |llmod| {
3000 cur: llvm::LLVMGetFirstGlobal(llmod),
3001 step: llvm::LLVMGetNextGlobal,
3005 let iter_functions = |llmod| {
3007 cur: llvm::LLVMGetFirstFunction(llmod),
3008 step: llvm::LLVMGetNextFunction,
3012 // Collect all external declarations in all compilation units.
3013 for ccx in cx.iter() {
3014 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3015 let linkage = llvm::LLVMGetLinkage(val);
3016 // We only care about external declarations (not definitions)
3017 // and available_externally definitions.
3018 if !(linkage == llvm::ExternalLinkage as c_uint &&
3019 llvm::LLVMIsDeclaration(val) != 0) &&
3020 !(linkage == llvm::AvailableExternallyLinkage as c_uint) {
3024 let name = CString::new(llvm::LLVMGetValueName(val), false);
3025 declared.insert(name);
3029 // Examine each external definition. If the definition is not used in
3030 // any other compilation unit, and is not reachable from other crates,
3031 // then give it internal linkage.
3032 for ccx in cx.iter() {
3033 for val in iter_globals(ccx.llmod()).chain(iter_functions(ccx.llmod())) {
3034 // We only care about external definitions.
3035 if !(llvm::LLVMGetLinkage(val) == llvm::ExternalLinkage as c_uint &&
3036 llvm::LLVMIsDeclaration(val) == 0) {
3040 let name = CString::new(llvm::LLVMGetValueName(val), false);
3041 if !declared.contains(&name) &&
3042 !reachable.contains(name.as_str().unwrap()) {
3043 llvm::SetLinkage(val, llvm::InternalLinkage);
3052 step: unsafe extern "C" fn(ValueRef) -> ValueRef,
3055 impl Iterator<ValueRef> for ValueIter {
3056 fn next(&mut self) -> Option<ValueRef> {
3060 let step: unsafe extern "C" fn(ValueRef) -> ValueRef =
3061 mem::transmute_copy(&self.step);
3072 pub fn trans_crate<'tcx>(analysis: ty::CrateAnalysis<'tcx>)
3073 -> (ty::ctxt<'tcx>, CrateTranslation) {
3074 let ty::CrateAnalysis { ty_cx: tcx, export_map, reachable, name, .. } = analysis;
3075 let krate = tcx.map.krate();
3077 // Before we touch LLVM, make sure that multithreading is enabled.
3079 use std::sync::{Once, ONCE_INIT};
3080 static INIT: Once = ONCE_INIT;
3081 static mut POISONED: bool = false;
3083 if llvm::LLVMStartMultithreaded() != 1 {
3084 // use an extra bool to make sure that all future usage of LLVM
3085 // cannot proceed despite the Once not running more than once.
3091 tcx.sess.bug("couldn't enable multi-threaded LLVM");
3095 let link_meta = link::build_link_meta(&tcx.sess, krate, name);
3097 let codegen_units = tcx.sess.opts.cg.codegen_units;
3098 let shared_ccx = SharedCrateContext::new(link_meta.crate_name.as_slice(),
3107 let ccx = shared_ccx.get_ccx(0);
3109 // First, verify intrinsics.
3110 intrinsic::check_intrinsics(&ccx);
3112 // Next, translate the module.
3114 let _icx = push_ctxt("text");
3115 trans_mod(&ccx, &krate.module);
3119 for ccx in shared_ccx.iter() {
3120 glue::emit_tydescs(&ccx);
3121 if ccx.sess().opts.debuginfo != NoDebugInfo {
3122 debuginfo::finalize(&ccx);
3126 // Translate the metadata.
3127 let metadata = write_metadata(&shared_ccx, krate);
3129 if shared_ccx.sess().trans_stats() {
3130 let stats = shared_ccx.stats();
3131 println!("--- trans stats ---");
3132 println!("n_static_tydescs: {}", stats.n_static_tydescs.get());
3133 println!("n_glues_created: {}", stats.n_glues_created.get());
3134 println!("n_null_glues: {}", stats.n_null_glues.get());
3135 println!("n_real_glues: {}", stats.n_real_glues.get());
3137 println!("n_fns: {}", stats.n_fns.get());
3138 println!("n_monos: {}", stats.n_monos.get());
3139 println!("n_inlines: {}", stats.n_inlines.get());
3140 println!("n_closures: {}", stats.n_closures.get());
3141 println!("fn stats:");
3142 stats.fn_stats.borrow_mut().sort_by(|&(_, insns_a), &(_, insns_b)| {
3143 insns_b.cmp(&insns_a)
3145 for tuple in stats.fn_stats.borrow().iter() {
3147 (ref name, insns) => {
3148 println!("{} insns, {}", insns, *name);
3153 if shared_ccx.sess().count_llvm_insns() {
3154 for (k, v) in shared_ccx.stats().llvm_insns.borrow().iter() {
3155 println!("{:7} {}", *v, *k);
3159 let modules = shared_ccx.iter()
3160 .map(|ccx| ModuleTranslation { llcx: ccx.llcx(), llmod: ccx.llmod() })
3163 let mut reachable: Vec<String> = shared_ccx.reachable().iter().filter_map(|id| {
3164 shared_ccx.item_symbols().borrow().get(id).map(|s| s.to_string())
3167 // For the purposes of LTO, we add to the reachable set all of the upstream
3168 // reachable extern fns. These functions are all part of the public ABI of
3169 // the final product, so LTO needs to preserve them.
3170 shared_ccx.sess().cstore.iter_crate_data(|cnum, _| {
3171 let syms = csearch::get_reachable_extern_fns(&shared_ccx.sess().cstore, cnum);
3172 reachable.extend(syms.into_iter().map(|did| {
3173 csearch::get_symbol(&shared_ccx.sess().cstore, did)
3177 // Make sure that some other crucial symbols are not eliminated from the
3178 // module. This includes the main function, the crate map (used for debug
3179 // log settings and I/O), and finally the curious rust_stack_exhausted
3180 // symbol. This symbol is required for use by the libmorestack library that
3181 // we link in, so we must ensure that this symbol is not internalized (if
3182 // defined in the crate).
3183 reachable.push("main".to_string());
3184 reachable.push("rust_stack_exhausted".to_string());
3186 // referenced from .eh_frame section on some platforms
3187 reachable.push("rust_eh_personality".to_string());
3188 // referenced from rt/rust_try.ll
3189 reachable.push("rust_eh_personality_catch".to_string());
3191 if codegen_units > 1 {
3192 internalize_symbols(&shared_ccx, &reachable.iter().map(|x| x.clone()).collect());
3195 let metadata_module = ModuleTranslation {
3196 llcx: shared_ccx.metadata_llcx(),
3197 llmod: shared_ccx.metadata_llmod(),
3199 let formats = shared_ccx.tcx().dependency_formats.borrow().clone();
3200 let no_builtins = attr::contains_name(krate.attrs.as_slice(), "no_builtins");
3202 let translation = CrateTranslation {
3204 metadata_module: metadata_module,
3207 reachable: reachable,
3208 crate_formats: formats,
3209 no_builtins: no_builtins,
3212 (shared_ccx.take_tcx(), translation)