Correctly align all allocs

Fixes rust-lang#348
rust-lang-ci · Aug 1, 2019 · c4af588 · c4af588
1 parent 2f0093b
commit c4af588
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Showing 4 changed files with 25 additions and 10 deletions.
diff --git a/build_sysroot/Cargo.toml b/build_sysroot/Cargo.toml
@@ -17,7 +17,3 @@ rustc-std-workspace-alloc = { path = "./rustc-std-workspace-alloc" }
 
 [profile.release]
 debug = true
-
-[profile.dev]
-# FIXME correctly align constants, so that copy_nonoverlapping doesn't complain about alignment
-debug-assertions = false
diff --git a/example/mini_core.rs b/example/mini_core.rs
@@ -186,6 +186,21 @@ impl Sub for i16 {
  }
 }
 
+#[lang = "rem"]
+pub trait Rem<RHS = Self> {
+ type Output;
+
+ fn rem(self, rhs: RHS) -> Self::Output;
+}
+
+impl Rem for usize {
+ type Output = Self;
+
+ fn rem(self, rhs: Self) -> Self {
+ self % rhs
+ }
+}
+
 #[lang = "bitor"]
 pub trait BitOr<RHS = Self> {
  type Output;

diff --git a/example/mini_core_hello_world.rs b/example/mini_core_hello_world.rs
@@ -134,6 +134,10 @@ fn main() {
 
  call_return_u128_pair();
 
+ let slice = &[0, 1] as &[i32];
+ let slice_ptr = slice as *const [i32] as *const i32;
+ assert_eq!(slice_ptr as usize % 4, 0);
+
  //return;
 
  unsafe {

diff --git a/src/constant.rs b/src/constant.rs
@@ -3,7 +3,7 @@ use std::borrow::Cow;
 use rustc::mir::interpret::{
  read_target_uint, AllocId, GlobalAlloc, Allocation, ConstValue, InterpResult, GlobalId, Scalar,
 };
-use rustc::ty::Const;
+use rustc::ty::{Const, layout::Align};
 use rustc_mir::interpret::{
  InterpCx, ImmTy, Machine, Memory, MemoryKind, OpTy, PlaceTy,
  StackPopCleanup,
@@ -170,13 +170,13 @@ fn trans_const_place<'a, 'tcx: 'a>(
  //println!("const value: {:?} allocation: {:?}", value, alloc);
  let alloc_id = fx.tcx.alloc_map.lock().create_memory_alloc(alloc);
  fx.constants.todo.insert(TodoItem::Alloc(alloc_id));
- let data_id = data_id_for_alloc_id(fx.module, alloc_id);
+ let data_id = data_id_for_alloc_id(fx.module, alloc_id, alloc.align);
  cplace_for_dataid(fx, const_.ty, data_id)
 }
 
-fn data_id_for_alloc_id(module: &mut Module<impl Backend>, alloc_id: AllocId) -> DataId {
+fn data_id_for_alloc_id<B: Backend>(module: &mut Module<B>, alloc_id: AllocId, align: Align) -> DataId {
  module
- .declare_data(&format!("__alloc_{}", alloc_id.0), Linkage::Local, false, None)
+ .declare_data(&format!("__alloc_{}", alloc_id.0), Linkage::Local, false, Some(align.bytes() as u8))
  .unwrap()
 }
 
@@ -245,8 +245,8 @@ fn define_all_allocs(
  let (data_id, alloc) = match todo_item {
  TodoItem::Alloc(alloc_id) => {
  //println!("alloc_id {}", alloc_id);
- let data_id = data_id_for_alloc_id(module, alloc_id);
  let alloc = memory.get(alloc_id).unwrap();
+ let data_id = data_id_for_alloc_id(module, alloc_id, alloc.align);
  (data_id, alloc)
  }
  TodoItem::Static(def_id) => {
@@ -302,7 +302,7 @@ fn define_all_allocs(
  }
  GlobalAlloc::Memory(_) => {
  cx.todo.insert(TodoItem::Alloc(reloc));
- data_id_for_alloc_id(module, reloc)
+ data_id_for_alloc_id(module, reloc, alloc.align)
  }
  GlobalAlloc::Static(def_id) => {
  cx.todo.insert(TodoItem::Static(def_id));