Auto merge of rust-lang#18119 - ChayimFriedman2:signed-const, r=HKalbasi

fix: Fix printing of constants greater than `i128::MAX`

Fixes rust-lang#18116.

crates/hir/src/lib.rs

@@ -80,7 +80,7 @@ use nameres::diagnostics::DefDiagnosticKind;
 use rustc_hash::FxHashSet;
 use smallvec::SmallVec;
 use span::{Edition, EditionedFileId, FileId, MacroCallId, SyntaxContextId};
-use stdx::{impl_from, never};
+use stdx::{format_to, impl_from, never};
 use syntax::{
  ast::{self, HasAttrs as _, HasGenericParams, HasName},
  format_smolstr, AstNode, AstPtr, SmolStr, SyntaxNode, SyntaxNodePtr, TextRange, ToSmolStr, T,
@@ -2578,10 +2578,16 @@ impl Const {
  let value = u128::from_le_bytes(mir::pad16(b, false));
  let value_signed =
  i128::from_le_bytes(mir::pad16(b, matches!(s, Scalar::Int(_))));
+ let mut result = if let Scalar::Int(_) = s {
+ value_signed.to_string()
+ } else {
+ value.to_string()
+ };
  if value >= 10 {
- return Ok(format!("{value_signed} ({value:#X})"));
+ format_to!(result, " ({value:#X})");
+ return Ok(result);
  } else {
- return Ok(format!("{value_signed}"));
+ return Ok(result);
  }
  }
  }

crates/ide/src/hover/tests.rs

@@ -1496,6 +1496,24 @@ const foo$0: u32 = {
  );
 }
 
+#[test]
+fn hover_unsigned_max_const() {
+ check(
+ r#"const $0A: u128 = -1_i128 as u128;"#,
+ expect![[r#"
+ *A*
+
+ ```rust
+ test
+ ```
+
+ ```rust
+ const A: u128 = 340282366920938463463374607431768211455 (0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF)
+ ```
+ "#]],
+ );
+}
+
 #[test]
 fn hover_eval_complex_constants() {
  check(