Rollup merge of #134055 - RalfJung:interpret-alloc-dedup, r=oli-obk

interpret: clean up deduplicating allocation functions

The "align" and "kind" arguments would be largely ignored in the "dedup" case, so let's move that to entirely separate function.

Let's also remove support for old-style miri_resolve_frame while we are at it. The docs have already said for a while that this must be set to 1.

Author: fmease

src/shims/backtrace.rs

@@ -1,5 +1,4 @@
 use rustc_abi::{ExternAbi, Size};
-use rustc_ast::ast::Mutability;
 use rustc_middle::ty::layout::LayoutOf as _;
 use rustc_middle::ty::{self, Instance, Ty};
 use rustc_span::{BytePos, Loc, Symbol, hygiene};
@@ -179,14 +178,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
 
         match flags {
             0 => {
-                // These are "mutable" allocations as we consider them to be owned by the callee.
-                let name_alloc =
-                    this.allocate_str(&name, MiriMemoryKind::Rust.into(), Mutability::Mut)?;
-                let filename_alloc =
-                    this.allocate_str(&filename, MiriMemoryKind::Rust.into(), Mutability::Mut)?;
-
-                this.write_immediate(name_alloc.to_ref(this), &this.project_field(dest, 0)?)?;
-                this.write_immediate(filename_alloc.to_ref(this), &this.project_field(dest, 1)?)?;
+                throw_unsup_format!("miri_resolve_frame: v0 is not supported any more");
             }
             1 => {
                 this.write_scalar(

src/shims/panic.rs

@@ -12,7 +12,6 @@
 //!   metadata we remembered when pushing said frame.
 
 use rustc_abi::ExternAbi;
-use rustc_ast::Mutability;
 use rustc_middle::{mir, ty};
 use rustc_target::spec::PanicStrategy;
 
@@ -161,7 +160,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let this = self.eval_context_mut();
 
         // First arg: message.
-        let msg = this.allocate_str(msg, MiriMemoryKind::Machine.into(), Mutability::Not)?;
+        let msg = this.allocate_str_dedup(msg)?;
 
         // Call the lang item.
         let panic = this.tcx.lang_items().panic_fn().unwrap();
@@ -180,7 +179,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let this = self.eval_context_mut();
 
         // First arg: message.
-        let msg = this.allocate_str(msg, MiriMemoryKind::Machine.into(), Mutability::Not)?;
+        let msg = this.allocate_str_dedup(msg)?;
 
         // Call the lang item.
         let panic = this.tcx.lang_items().panic_nounwind().unwrap();