Auto merge of #119627 - oli-obk:const_prop_lint_n̵o̵n̵sense, r=cjgillot

Remove all ConstPropNonsense

We track all locals and projections on them ourselves within the const propagator and only use the InterpCx to actually do some low level operations or read from constants (via `OpTy` we get for said constants).

This helps moving the const prop lint out from the normal pipeline and running it just based on borrowck information. This in turn allows us to make progress on https://github.com/rust-lang/rust/pull/108730#issuecomment-1875557745

there are various follow up cleanups that can be done after this PR (e.g. not matching on Rvalue twice and doing binop checks twice), but lets try landing this one first.

r? `@RalfJung`

1 files changed, 18 insertions, 24 deletions

diff --git a/compiler/rustc_mir_transform/src/errors.rs b/compiler/rustc_mir_transform/src/errors.rs
index 2ee660ddc9b..4574cb4d28d 100644
--- a/compiler/rustc_mir_transform/src/errors.rs
+++ b/compiler/rustc_mir_transform/src/errors.rs
@@ -201,45 +201,39 @@ impl<'a> DecorateLint<'a, ()> for UnsafeOpInUnsafeFn {
     }
 }
 
-pub(crate) enum AssertLint<P> {
-    ArithmeticOverflow(Span, AssertKind<P>),
-    UnconditionalPanic(Span, AssertKind<P>),
+pub(crate) struct AssertLint<P> {
+    pub span: Span,
+    pub assert_kind: AssertKind<P>,
+    pub lint_kind: AssertLintKind,
+}
+
+pub(crate) enum AssertLintKind {
+    ArithmeticOverflow,
+    UnconditionalPanic,
 }
 
 impl<'a, P: std::fmt::Debug> DecorateLint<'a, ()> for AssertLint<P> {
     fn decorate_lint<'b>(self, diag: &'b mut DiagnosticBuilder<'a, ()>) {
-        let span = self.span();
-        let assert_kind = self.panic();
-        let message = assert_kind.diagnostic_message();
-        assert_kind.add_args(&mut |name, value| {
+        let message = self.assert_kind.diagnostic_message();
+        self.assert_kind.add_args(&mut |name, value| {
             diag.arg(name, value);
         });
-        diag.span_label(span, message);
+        diag.span_label(self.span, message);
     }
 
     fn msg(&self) -> DiagnosticMessage {
-        match self {
-            AssertLint::ArithmeticOverflow(..) => fluent::mir_transform_arithmetic_overflow,
-            AssertLint::UnconditionalPanic(..) => fluent::mir_transform_operation_will_panic,
+        match self.lint_kind {
+            AssertLintKind::ArithmeticOverflow => fluent::mir_transform_arithmetic_overflow,
+            AssertLintKind::UnconditionalPanic => fluent::mir_transform_operation_will_panic,
         }
     }
 }
 
-impl<P> AssertLint<P> {
+impl AssertLintKind {
     pub fn lint(&self) -> &'static Lint {
         match self {
-            AssertLint::ArithmeticOverflow(..) => lint::builtin::ARITHMETIC_OVERFLOW,
-            AssertLint::UnconditionalPanic(..) => lint::builtin::UNCONDITIONAL_PANIC,
-        }
-    }
-    pub fn span(&self) -> Span {
-        match self {
-            AssertLint::ArithmeticOverflow(sp, _) | AssertLint::UnconditionalPanic(sp, _) => *sp,
-        }
-    }
-    pub fn panic(self) -> AssertKind<P> {
-        match self {
-            AssertLint::ArithmeticOverflow(_, p) | AssertLint::UnconditionalPanic(_, p) => p,
+            AssertLintKind::ArithmeticOverflow => lint::builtin::ARITHMETIC_OVERFLOW,
+            AssertLintKind::UnconditionalPanic => lint::builtin::UNCONDITIONAL_PANIC,
         }
     }
 }