From dda6c8cf2f035d23ff3f67c5fc0e805bb18cd0a4 Mon Sep 17 00:00:00 2001
From: Mark-Simulacrum <mark.simulacrum@gmail.com>
Date: Thu, 15 Dec 2016 18:00:19 -0700
Subject: [PATCH] Inline base::malloc_raw_dyn.

Move comment about not unwinding into liballoc.
---
 src/liballoc/heap.rs              |  1 +
 src/librustc/middle/lang_items.rs |  2 --
 src/librustc_trans/base.rs        | 29 +----------------------------
 src/librustc_trans/mir/rvalue.rs  | 14 +++++++++++++-
 4 files changed, 15 insertions(+), 31 deletions(-)

diff --git a/src/liballoc/heap.rs b/src/liballoc/heap.rs
index 12809171b74..a1e32636980 100644
--- a/src/liballoc/heap.rs
+++ b/src/liballoc/heap.rs
@@ -127,6 +127,7 @@ pub fn usable_size(size: usize, align: usize) -> usize {
 pub const EMPTY: *mut () = 0x1 as *mut ();
 
 /// The allocator for unique pointers.
+// This function must not unwind. If it does, MIR trans will fail.
 #[cfg(not(test))]
 #[lang = "exchange_malloc"]
 #[inline]
diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs
index 3bc39fad7f1..1efc211b8c3 100644
--- a/src/librustc/middle/lang_items.rs
+++ b/src/librustc/middle/lang_items.rs
@@ -327,8 +327,6 @@ language_item_table! {
     PanicBoundsCheckFnLangItem,      "panic_bounds_check",      panic_bounds_check_fn;
     PanicFmtLangItem,                "panic_fmt",               panic_fmt;
 
-    // ExchangeMallocFnLangItem cannot unwind, or MIR trans will break. See note
-    // on `malloc_raw_dyn` in librustc_trans/base.rs.
     ExchangeMallocFnLangItem,        "exchange_malloc",         exchange_malloc_fn;
     ExchangeFreeFnLangItem,          "exchange_free",           exchange_free_fn;
     BoxFreeFnLangItem,               "box_free",                box_free_fn;
diff --git a/src/librustc_trans/base.rs b/src/librustc_trans/base.rs
index 011552b3962..3f477a463ab 100644
--- a/src/librustc_trans/base.rs
+++ b/src/librustc_trans/base.rs
@@ -37,7 +37,7 @@ use back::symbol_export::{self, ExportedSymbols};
 use llvm::{Linkage, ValueRef, Vector, get_param};
 use llvm;
 use rustc::hir::def_id::{DefId, LOCAL_CRATE};
-use middle::lang_items::{LangItem, ExchangeMallocFnLangItem, StartFnLangItem};
+use middle::lang_items::StartFnLangItem;
 use rustc::ty::subst::Substs;
 use rustc::traits;
 use rustc::ty::{self, Ty, TyCtxt, TypeFoldable};
@@ -168,33 +168,6 @@ pub fn get_dataptr(bcx: &Builder, fat_ptr: ValueRef) -> ValueRef {
     bcx.struct_gep(fat_ptr, abi::FAT_PTR_ADDR)
 }
 
-fn require_alloc_fn<'blk, 'tcx>(
-    bcx: &BlockAndBuilder<'blk, 'tcx>, info_ty: Ty<'tcx>, it: LangItem
-) -> DefId {
-    match bcx.tcx().lang_items.require(it) {
-        Ok(id) => id,
-        Err(s) => {
-            bcx.sess().fatal(&format!("allocation of `{}` {}", info_ty, s));
-        }
-    }
-}
-
-// malloc_raw_dyn allocates a box to contain a given type, but with a potentially dynamic size.
-//
-// MIR requires that ExchangeMallocFnLangItem cannot unwind.
-pub fn malloc_raw_dyn<'blk, 'tcx>(bcx: &BlockAndBuilder<'blk, 'tcx>,
-                                  llty_ptr: Type,
-                                  info_ty: Ty<'tcx>,
-                                  size: ValueRef,
-                                  align: ValueRef)
-                                  -> ValueRef {
-    // Allocate space:
-    let def_id = require_alloc_fn(bcx, info_ty, ExchangeMallocFnLangItem);
-    let r = Callee::def(bcx.ccx(), def_id, bcx.tcx().intern_substs(&[])).reify(bcx.ccx());
-    bcx.pointercast(bcx.call(r, &[size, align], None), llty_ptr)
-}
-
-
 pub fn bin_op_to_icmp_predicate(op: hir::BinOp_,
                                 signed: bool)
                                 -> llvm::IntPredicate {
diff --git a/src/librustc_trans/mir/rvalue.rs b/src/librustc_trans/mir/rvalue.rs
index 5aba7160c23..d15598e76af 100644
--- a/src/librustc_trans/mir/rvalue.rs
+++ b/src/librustc_trans/mir/rvalue.rs
@@ -13,6 +13,7 @@ use rustc::ty::{self, Ty};
 use rustc::ty::cast::{CastTy, IntTy};
 use rustc::ty::layout::Layout;
 use rustc::mir;
+use middle::lang_items::ExchangeMallocFnLangItem;
 
 use asm;
 use base;
@@ -449,7 +450,18 @@ impl<'bcx, 'tcx> MirContext<'bcx, 'tcx> {
                 let llalign = C_uint(bcx.ccx(), align);
                 let llty_ptr = llty.ptr_to();
                 let box_ty = bcx.tcx().mk_box(content_ty);
-                let val = base::malloc_raw_dyn(&bcx, llty_ptr, box_ty, llsize, llalign);
+
+                // Allocate space:
+                let def_id = match bcx.tcx().lang_items.require(ExchangeMallocFnLangItem) {
+                    Ok(id) => id,
+                    Err(s) => {
+                        bcx.sess().fatal(&format!("allocation of `{}` {}", box_ty, s));
+                    }
+                };
+                let r = Callee::def(bcx.ccx(), def_id, bcx.tcx().intern_substs(&[]))
+                    .reify(bcx.ccx());
+                let val = bcx.pointercast(bcx.call(r, &[llsize, llalign], None), llty_ptr);
+
                 let operand = OperandRef {
                     val: OperandValue::Immediate(val),
                     ty: box_ty,