Auto merge of #115865 - RalfJung:mir-mod, r=oli-obk

move things out of mir/mod.rs

This moves a bunch of things out of `mir/mod.rs`:
- all const-related stuff to a new file consts.rs
- all statement/place/operand-related stuff to a new file statement.rs
- all pretty-printing related stuff to pretty.rs

`mod.rs` started out with 3100 lines and ends up with 1600. :)

Also there was some pretty-printing stuff in terminator.rs, that also got moved to pretty.rs, and I reordered things in pretty.rs so that it can be grouped by functionality.

Only the commit "use pretty_print_const_value from MIR constant 'extra' printing" has any behavior changes; it resolves the issue of having a fancy and a very crude pretty-printer for `ConstValue`.

r? `@oli-obk`

Author: bors

compiler/rustc_const_eval/src/interpret/place.rs

@@ -9,16 +9,15 @@ use either::{Either, Left, Right};
 use rustc_ast::Mutability;
 use rustc_index::IndexSlice;
 use rustc_middle::mir;
-use rustc_middle::mir::interpret::PointerArithmetic;
 use rustc_middle::ty;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::ty::Ty;
 use rustc_target::abi::{Abi, Align, FieldIdx, HasDataLayout, Size, FIRST_VARIANT};
 
 use super::{
-    alloc_range, mir_assign_valid_types, AllocId, AllocRef, AllocRefMut, CheckInAllocMsg,
-    ConstAlloc, ImmTy, Immediate, InterpCx, InterpResult, Machine, MemoryKind, OpTy, Operand,
-    Pointer, Projectable, Provenance, Readable, Scalar,
+    alloc_range, mir_assign_valid_types, AllocId, AllocRef, AllocRefMut, CheckInAllocMsg, ImmTy,
+    Immediate, InterpCx, InterpResult, Machine, MemoryKind, OpTy, Operand, Pointer,
+    PointerArithmetic, Projectable, Provenance, Readable, Scalar,
 };
 
 #[derive(Copy, Clone, Hash, PartialEq, Eq, Debug)]
@@ -1037,7 +1036,7 @@ where
 
     pub fn raw_const_to_mplace(
         &self,
-        raw: ConstAlloc<'tcx>,
+        raw: mir::ConstAlloc<'tcx>,
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::Provenance>> {
         // This must be an allocation in `tcx`
         let _ = self.tcx.global_alloc(raw.alloc_id);

compiler/rustc_data_structures/src/lib.rs

@@ -47,6 +47,8 @@ extern crate cfg_if;
 #[macro_use]
 extern crate rustc_macros;
 
+use std::fmt;
+
 pub use rustc_index::static_assert_size;
 
 #[inline(never)]
@@ -126,6 +128,23 @@ impl<F: FnOnce()> Drop for OnDrop<F> {
     }
 }
 
+/// Turns a closure that takes an `&mut Formatter` into something that can be display-formatted.
+pub fn make_display(f: impl Fn(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Display {
+    struct Printer<F> {
+        f: F,
+    }
+    impl<F> fmt::Display for Printer<F>
+    where
+        F: Fn(&mut fmt::Formatter<'_>) -> fmt::Result,
+    {
+        fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+            (self.f)(fmt)
+        }
+    }
+
+    Printer { f }
+}
+
 // See comments in src/librustc_middle/lib.rs
 #[doc(hidden)]
 pub fn __noop_fix_for_27438() {}