Sync from rust 0288f2e

Author: bjorn3

src/constant.rs

@@ -3,7 +3,8 @@
 use cranelift_module::*;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;
-use rustc_middle::mir::interpret::{read_target_uint, AllocId, ConstValue, GlobalAlloc, Scalar};
+use rustc_middle::mir::interpret::{read_target_uint, AllocId, GlobalAlloc, Scalar};
+use rustc_middle::mir::ConstValue;
 
 use crate::prelude::*;
 
@@ -62,9 +63,9 @@ pub(crate) fn codegen_tls_ref<'tcx>(
 
 pub(crate) fn eval_mir_constant<'tcx>(
     fx: &FunctionCx<'_, '_, 'tcx>,
-    constant: &Constant<'tcx>,
+    constant: &ConstOperand<'tcx>,
 ) -> (ConstValue<'tcx>, Ty<'tcx>) {
-    let cv = fx.monomorphize(constant.literal);
+    let cv = fx.monomorphize(constant.const_);
     // This cannot fail because we checked all required_consts in advance.
     let val = cv
         .eval(fx.tcx, ty::ParamEnv::reveal_all(), Some(constant.span))
@@ -74,7 +75,7 @@ pub(crate) fn eval_mir_constant<'tcx>(
 
 pub(crate) fn codegen_constant_operand<'tcx>(
     fx: &mut FunctionCx<'_, '_, 'tcx>,
-    constant: &Constant<'tcx>,
+    constant: &ConstOperand<'tcx>,
 ) -> CValue<'tcx> {
     let (const_val, ty) = eval_mir_constant(fx, constant);
     codegen_const_value(fx, const_val, ty)
@@ -182,15 +183,11 @@ pub(crate) fn codegen_const_value<'tcx>(
                 .offset_i64(fx, i64::try_from(offset.bytes()).unwrap()),
             layout,
         ),
-        ConstValue::Slice { data, start, end } => {
+        ConstValue::Slice { data, meta } => {
             let alloc_id = fx.tcx.reserve_and_set_memory_alloc(data);
-            let ptr = pointer_for_allocation(fx, alloc_id)
-                .offset_i64(fx, i64::try_from(start).unwrap())
-                .get_addr(fx);
-            let len = fx
-                .bcx
-                .ins()
-                .iconst(fx.pointer_type, i64::try_from(end.checked_sub(start).unwrap()).unwrap());
+            let ptr = pointer_for_allocation(fx, alloc_id).get_addr(fx);
+            // FIXME: the `try_from` here can actually fail, e.g. for very long ZST slices.
+            let len = fx.bcx.ins().iconst(fx.pointer_type, i64::try_from(meta).unwrap());
             CValue::by_val_pair(ptr, len, layout)
         }
     }

src/inline_asm.rs

@@ -252,8 +252,8 @@ pub(crate) fn codegen_inline_asm<'tcx>(
                 CInlineAsmOperand::Const { value }
             }
             InlineAsmOperand::SymFn { ref value } => {
-                let literal = fx.monomorphize(value.literal);
-                if let ty::FnDef(def_id, args) = *literal.ty().kind() {
+                let const_ = fx.monomorphize(value.const_);
+                if let ty::FnDef(def_id, args) = *const_.ty().kind() {
                     let instance = ty::Instance::resolve_for_fn_ptr(
                         fx.tcx,
                         ty::ParamEnv::reveal_all(),