Reuse the Pointer type instead of passing reassembling it at many use sites

Author: oli-obk

src/librustc/ich/impls_ty.rs

@@ -307,7 +307,7 @@ impl_stable_hash_for!(
     impl<'tcx> for enum mir::interpret::ConstValue<'tcx> [ mir::interpret::ConstValue ] {
         Scalar(val),
         Slice(a, b),
-        ByRef(id, alloc, offset),
+        ByRef(ptr, alloc),
     }
 );
 impl_stable_hash_for!(struct crate::mir::interpret::RawConst<'tcx> {

src/librustc/mir/interpret/value.rs

@@ -31,9 +31,8 @@ pub enum ConstValue<'tcx> {
     /// it.
     Slice(Scalar, u64),
 
-    /// An allocation together with an offset into the allocation.
-    /// Invariant: the `AllocId` matches the allocation.
-    ByRef(AllocId, &'tcx Allocation, Size),
+    /// An allocation together with a pointer into the allocation.
+    ByRef(Pointer, &'tcx Allocation),
 }
 
 #[cfg(target_arch = "x86_64")]

src/librustc/ty/structural_impls.rs

@@ -499,8 +499,8 @@ impl<'a, 'tcx> Lift<'tcx> for ConstValue<'a> {
         match *self {
             ConstValue::Scalar(x) => Some(ConstValue::Scalar(x)),
             ConstValue::Slice(x, y) => Some(ConstValue::Slice(x, y)),
-            ConstValue::ByRef(x, alloc, z) => Some(ConstValue::ByRef(
-                x, alloc.lift_to_tcx(tcx)?, z,
+            ConstValue::ByRef(ptr, alloc) => Some(ConstValue::ByRef(
+                ptr, alloc.lift_to_tcx(tcx)?,
             )),
         }
     }

src/librustc_codegen_llvm/consts.rs

@@ -71,7 +71,7 @@ pub fn codegen_static_initializer(
     let static_ = cx.tcx.const_eval(param_env.and(cid))?;
 
     let alloc = match static_.val {
-        ConstValue::ByRef(_, alloc, n) if n.bytes() == 0 => alloc,
+        ConstValue::ByRef(ptr, alloc) if ptr.offset.bytes() == 0 => alloc,
         _ => bug!("static const eval returned {:#?}", static_),
     };
     Ok((const_alloc_to_llvm(cx, alloc), alloc))

src/librustc_codegen_ssa/mir/operand.rs

@@ -101,8 +101,8 @@ impl<'a, 'tcx: 'a, V: CodegenObject> OperandRef<'tcx, V> {
                 let b_llval = bx.cx().const_usize(b);
                 OperandValue::Pair(a_llval, b_llval)
             },
-            ConstValue::ByRef(_, alloc, offset) => {
-                return Ok(bx.load_operand(bx.cx().from_const_alloc(layout, alloc, offset)));
+            ConstValue::ByRef(ptr, alloc) => {
+                return Ok(bx.load_operand(bx.cx().from_const_alloc(layout, alloc, ptr.offset)));
             },
         };
 

src/librustc_codegen_ssa/mir/place.rs

@@ -417,8 +417,8 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 let layout = cx.layout_of(self.monomorphize(&ty));
                 match bx.tcx().const_eval(param_env.and(cid)) {
                     Ok(val) => match val.val {
-                        mir::interpret::ConstValue::ByRef(_, alloc, offset) => {
-                            bx.cx().from_const_alloc(layout, alloc, offset)
+                        mir::interpret::ConstValue::ByRef(ptr, alloc) => {
+                            bx.cx().from_const_alloc(layout, alloc, ptr.offset)
                         }
                         _ => bug!("promoteds should have an allocation: {:?}", val),
                     },

src/librustc_mir/const_eval.rs

@@ -96,7 +96,7 @@ pub fn op_to_const<'tcx>(
             // FIXME shouldn't it be the case that `mark_static_initialized` has already
             // interned this?  I thought that is the entire point of that `FinishStatic` stuff?
             let alloc = ecx.tcx.intern_const_alloc(alloc);
-            ConstValue::ByRef(ptr.alloc_id, alloc, ptr.offset)
+            ConstValue::ByRef(ptr, alloc)
         },
         Ok(Immediate::Scalar(x)) =>
             ConstValue::Scalar(x.not_undef()?),

src/librustc_mir/hair/pattern/_match.rs

@@ -172,7 +172,7 @@ use rustc::ty::{self, Ty, TyCtxt, TypeFoldable, Const};
 use rustc::ty::layout::{Integer, IntegerExt, VariantIdx, Size};
 
 use rustc::mir::Field;
-use rustc::mir::interpret::{ConstValue, Pointer, Scalar};
+use rustc::mir::interpret::{ConstValue, Scalar};
 use rustc::util::common::ErrorReported;
 
 use syntax::attr::{SignedInt, UnsignedInt};
@@ -214,9 +214,8 @@ impl<'a, 'tcx> LiteralExpander<'a, 'tcx> {
         match (val, &crty.sty, &rty.sty) {
             // the easy case, deref a reference
             (ConstValue::Scalar(Scalar::Ptr(p)), x, y) if x == y => ConstValue::ByRef(
-                p.alloc_id,
+                p,
                 self.tcx.alloc_map.lock().unwrap_memory(p.alloc_id),
-                p.offset,
             ),
             // unsize array to slice if pattern is array but match value or other patterns are slice
             (ConstValue::Scalar(Scalar::Ptr(p)), ty::Array(t, n), ty::Slice(u)) => {
@@ -1428,15 +1427,14 @@ fn slice_pat_covered_by_const<'tcx>(
     suffix: &[Pattern<'tcx>]
 ) -> Result<bool, ErrorReported> {
     let data: &[u8] = match (const_val.val, &const_val.ty.sty) {
-        (ConstValue::ByRef(id, alloc, offset), ty::Array(t, n)) => {
+        (ConstValue::ByRef(ptr, alloc), ty::Array(t, n)) => {
             if *t != tcx.types.u8 {
                 // FIXME(oli-obk): can't mix const patterns with slice patterns and get
                 // any sort of exhaustiveness/unreachable check yet
                 // This solely means that we don't lint about unreachable patterns, even if some
                 // are definitely unreachable.
                 return Ok(false);
             }
-            let ptr = Pointer::new(id, offset);
             let n = n.assert_usize(tcx).unwrap();
             alloc.get_bytes(&tcx, ptr, Size::from_bytes(n)).unwrap()
         },
@@ -1778,8 +1776,8 @@ fn specialize<'p, 'a: 'p, 'tcx: 'a>(
                     let (opt_ptr, n, ty) = match value.ty.sty {
                         ty::TyKind::Array(t, n) => {
                             match value.val {
-                                ConstValue::ByRef(id, alloc, offset) => (
-                                    Some((Pointer::new(id, offset), alloc)),
+                                ConstValue::ByRef(ptr, alloc) => (
+                                    Some((ptr, alloc)),
                                     n.unwrap_usize(cx.tcx),
                                     t,
                                 ),

src/librustc_mir/interpret/operand.rs

@@ -591,11 +591,11 @@ impl<'a, 'mir, 'tcx, M: Machine<'a, 'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M>
             self.layout_of(ty)
         })?;
         let op = match val.val {
-            ConstValue::ByRef(id, alloc, offset) => {
+            ConstValue::ByRef(ptr, alloc) => {
                 // We rely on mutability being set correctly in that allocation to prevent writes
                 // where none should happen -- and for `static mut`, we copy on demand anyway.
                 Operand::Indirect(
-                    MemPlace::from_ptr(Pointer::new(id, offset), alloc.align)
+                    MemPlace::from_ptr(ptr, alloc.align)
                 ).with_default_tag()
             },
             ConstValue::Slice(a, b) =>

src/librustc_mir/monomorphize/collector.rs

@@ -1257,7 +1257,7 @@ fn collect_const<'a, 'tcx>(
         ConstValue::Slice(Scalar::Ptr(ptr), _) |
         ConstValue::Scalar(Scalar::Ptr(ptr)) =>
             collect_miri(tcx, ptr.alloc_id, output),
-        ConstValue::ByRef(_id, alloc, _offset) => {
+        ConstValue::ByRef(_ptr, alloc) => {
             for &((), id) in alloc.relocations.values() {
                 collect_miri(tcx, id, output);
             }

src/librustc_typeck/check/mod.rs

@@ -1464,7 +1464,7 @@ fn maybe_check_static_with_link_section(tcx: TyCtxt, id: DefId, span: Span) {
     };
     let param_env = ty::ParamEnv::reveal_all();
     if let Ok(static_) = tcx.const_eval(param_env.and(cid)) {
-        let alloc = if let ConstValue::ByRef(_, allocation, _) = static_.val {
+        let alloc = if let ConstValue::ByRef(_, allocation) = static_.val {
             allocation
         } else {
             bug!("Matching on non-ByRef static")