internal: Show mir eval errors on hover with debug env var set

Veykril · Veykril · commit 9e22cbf48bc1 · 2024-12-15T17:38:37.000+01:00
diff --git a/src/tools/rust-analyzer/crates/hir/src/lib.rs b/src/tools/rust-analyzer/crates/hir/src/lib.rs
@@ -2649,24 +2649,31 @@ impl Const {
         Type::from_value_def(db, self.id)
     }
 
-    /// Evaluate the constant and return the result as a string.
-    ///
-    /// This function is intended for IDE assistance, different from [`Const::render_eval`].
-    pub fn eval(self, db: &dyn HirDatabase) -> Result<String, ConstEvalError> {
-        let c = db.const_eval(self.id.into(), Substitution::empty(Interner), None)?;
-        Ok(format!("{}", c.display(db, self.krate(db).edition(db))))
+    /// Evaluate the constant.
+    pub fn eval(self, db: &dyn HirDatabase) -> Result<EvaluatedConst, ConstEvalError> {
+        db.const_eval(self.id.into(), Substitution::empty(Interner), None)
+            .map(|it| EvaluatedConst { const_: it, def: self.id.into() })
     }
+}
 
-    /// Evaluate the constant and return the result as a string, with more detailed information.
-    ///
-    /// This function is intended for user-facing display.
-    pub fn render_eval(
-        self,
-        db: &dyn HirDatabase,
-        edition: Edition,
-    ) -> Result<String, ConstEvalError> {
-        let c = db.const_eval(self.id.into(), Substitution::empty(Interner), None)?;
-        let data = &c.data(Interner);
+impl HasVisibility for Const {
+    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
+        db.const_visibility(self.id)
+    }
+}
+
+pub struct EvaluatedConst {
+    def: DefWithBodyId,
+    const_: hir_ty::Const,
+}
+
+impl EvaluatedConst {
+    pub fn render(&self, db: &dyn HirDatabase, edition: Edition) -> String {
+        format!("{}", self.const_.display(db, edition))
+    }
+
+    pub fn render_debug(&self, db: &dyn HirDatabase) -> Result<String, MirEvalError> {
+        let data = self.const_.data(Interner);
         if let TyKind::Scalar(s) = data.ty.kind(Interner) {
             if matches!(s, Scalar::Int(_) | Scalar::Uint(_)) {
                 if let hir_ty::ConstValue::Concrete(c) = &data.value {
@@ -2689,17 +2696,7 @@ impl Const {
                 }
             }
         }
-        if let Ok(s) = mir::render_const_using_debug_impl(db, self.id.into(), &c) {
-            Ok(s)
-        } else {
-            Ok(format!("{}", c.display(db, edition)))
-        }
-    }
-}
-
-impl HasVisibility for Const {
-    fn visibility(&self, db: &dyn HirDatabase) -> Visibility {
-        db.const_visibility(self.id)
+        mir::render_const_using_debug_impl(db, self.def, &self.const_)
     }
 }
 
@@ -2729,51 +2726,10 @@ impl Static {
         Type::from_value_def(db, self.id)
     }
 
-    /// Evaluate the static and return the result as a string.
-    ///
-    /// This function is intended for IDE assistance, different from [`Static::render_eval`].
-    pub fn eval(self, db: &dyn HirDatabase) -> Result<String, ConstEvalError> {
-        let c = db.const_eval(self.id.into(), Substitution::empty(Interner), None)?;
-        Ok(format!("{}", c.display(db, self.krate(db).edition(db))))
-    }
-
-    /// Evaluate the static and return the result as a string, with more detailed information.
-    ///
-    /// This function is intended for user-facing display.
-    pub fn render_eval(
-        self,
-        db: &dyn HirDatabase,
-        edition: Edition,
-    ) -> Result<String, ConstEvalError> {
-        let c = db.const_eval(self.id.into(), Substitution::empty(Interner), None)?;
-        let data = &c.data(Interner);
-        if let TyKind::Scalar(s) = data.ty.kind(Interner) {
-            if matches!(s, Scalar::Int(_) | Scalar::Uint(_)) {
-                if let hir_ty::ConstValue::Concrete(c) = &data.value {
-                    if let hir_ty::ConstScalar::Bytes(b, _) = &c.interned {
-                        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 {
-                            format_to!(result, " ({value:#X})");
-                            return Ok(result);
-                        } else {
-                            return Ok(result);
-                        }
-                    }
-                }
-            }
-        }
-        if let Ok(s) = mir::render_const_using_debug_impl(db, self.id.into(), &c) {
-            Ok(s)
-        } else {
-            Ok(format!("{}", c.display(db, edition)))
-        }
+    /// Evaluate the static initializer.
+    pub fn eval(self, db: &dyn HirDatabase) -> Result<EvaluatedConst, ConstEvalError> {
+        db.const_eval(self.id.into(), Substitution::empty(Interner), None)
+            .map(|it| EvaluatedConst { const_: it, def: self.id.into() })
     }
 }
 
diff --git a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/inline_const_as_literal.rs b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/inline_const_as_literal.rs
@@ -1,3 +1,4 @@
+use hir::HasCrate;
 use syntax::{ast, AstNode};
 
 use crate::{AssistContext, AssistId, AssistKind, Assists};
@@ -51,7 +52,10 @@ pub(crate) fn inline_const_as_literal(acc: &mut Assists, ctx: &AssistContext<'_>
             | ast::Expr::MatchExpr(_)
             | ast::Expr::MacroExpr(_)
             | ast::Expr::BinExpr(_)
-            | ast::Expr::CallExpr(_) => konst.eval(ctx.sema.db).ok()?,
+            | ast::Expr::CallExpr(_) => konst
+                .eval(ctx.sema.db)
+                .ok()?
+                .render(ctx.sema.db, konst.krate(ctx.sema.db).edition(ctx.sema.db)),
             _ => return None,
         };
 
diff --git a/src/tools/rust-analyzer/crates/ide/src/hover/render.rs b/src/tools/rust-analyzer/crates/ide/src/hover/render.rs
@@ -1,5 +1,5 @@
 //! Logic for rendering the different hover messages
-use std::{mem, ops::Not};
+use std::{env, mem, ops::Not};
 
 use either::Either;
 use hir::{
@@ -28,6 +28,7 @@ use syntax::{algo, ast, match_ast, AstNode, AstToken, Direction, SyntaxToken, T}
 use crate::{
     doc_links::{remove_links, rewrite_links},
     hover::{notable_traits, walk_and_push_ty},
+    interpret::render_const_eval_error,
     HoverAction, HoverConfig, HoverResult, Markup, MemoryLayoutHoverConfig,
     MemoryLayoutHoverRenderKind,
 };
@@ -464,41 +465,77 @@ pub(super) fn definition(
                     Ok(it) => {
                         Some(if it >= 10 { format!("{it} ({it:#X})") } else { format!("{it}") })
                     }
-                    Err(_) => it.value(db).map(|it| format!("{it:?}")),
+                    Err(err) => {
+                        let res = it.value(db).map(|it| format!("{it:?}"));
+                        if env::var_os("RA_DEV").is_some() {
+                            let res = res.as_deref().unwrap_or("");
+                            Some(format!("{res} ({})", render_const_eval_error(db, err, edition)))
+                        } else {
+                            res
+                        }
+                    }
                 }
             } else {
                 None
             }
         }
         Definition::Const(it) => {
-            let body = it.render_eval(db, edition);
-            match body {
-                Ok(it) => Some(it),
-                Err(_) => {
+            let body = it.eval(db);
+            Some(match body {
+                Ok(it) => match it.render_debug(db) {
+                    Ok(it) => it,
+                    Err(err) => {
+                        let it = it.render(db, edition);
+                        if env::var_os("RA_DEV").is_some() {
+                            format!("{it}\n{}", render_const_eval_error(db, err.into(), edition))
+                        } else {
+                            it
+                        }
+                    }
+                },
+                Err(err) => {
                     let source = it.source(db)?;
                     let mut body = source.value.body()?.syntax().clone();
                     if let Some(macro_file) = source.file_id.macro_file() {
                         let span_map = db.expansion_span_map(macro_file);
                         body = prettify_macro_expansion(db, body, &span_map, it.krate(db).into());
                     }
-                    Some(body.to_string())
+                    if env::var_os("RA_DEV").is_some() {
+                        format!("{body}\n{}", render_const_eval_error(db, err, edition))
+                    } else {
+                        body.to_string()
+                    }
                 }
-            }
+            })
         }
         Definition::Static(it) => {
-            let body = it.render_eval(db, edition);
-            match body {
-                Ok(it) => Some(it),
-                Err(_) => {
+            let body = it.eval(db);
+            Some(match body {
+                Ok(it) => match it.render_debug(db) {
+                    Ok(it) => it,
+                    Err(err) => {
+                        let it = it.render(db, edition);
+                        if env::var_os("RA_DEV").is_some() {
+                            format!("{it}\n{}", render_const_eval_error(db, err.into(), edition))
+                        } else {
+                            it
+                        }
+                    }
+                },
+                Err(err) => {
                     let source = it.source(db)?;
                     let mut body = source.value.body()?.syntax().clone();
                     if let Some(macro_file) = source.file_id.macro_file() {
                         let span_map = db.expansion_span_map(macro_file);
                         body = prettify_macro_expansion(db, body, &span_map, it.krate(db).into());
                     }
-                    Some(body.to_string())
+                    if env::var_os("RA_DEV").is_some() {
+                        format!("{body}\n{}", render_const_eval_error(db, err, edition))
+                    } else {
+                        body.to_string()
+                    }
                 }
-            }
+            })
         }
         _ => None,
     };
diff --git a/src/tools/rust-analyzer/crates/ide/src/interpret.rs b/src/tools/rust-analyzer/crates/ide/src/interpret.rs
@@ -1,5 +1,6 @@
-use hir::{DefWithBody, Semantics};
+use hir::{ConstEvalError, DefWithBody, Semantics};
 use ide_db::{base_db::SourceRootDatabase, FilePosition, LineIndexDatabase, RootDatabase};
+use span::Edition;
 use std::time::{Duration, Instant};
 use stdx::format_to;
 use syntax::{algo::ancestors_at_offset, ast, AstNode, TextRange};
@@ -47,18 +48,36 @@ fn find_and_interpret(db: &RootDatabase, position: FilePosition) -> Option<(Dura
             None => format!("file://{path} range {text_range:?}"),
         }
     };
+    let edition = def.module(db).krate().edition(db);
     let start_time = Instant::now();
     let res = match def {
         DefWithBody::Function(it) => it.eval(db, span_formatter),
-        DefWithBody::Static(it) => it.eval(db),
-        DefWithBody::Const(it) => it.eval(db),
+        DefWithBody::Static(it) => it.eval(db).map(|it| it.render(db, edition)),
+        DefWithBody::Const(it) => it.eval(db).map(|it| it.render(db, edition)),
         _ => unreachable!(),
     };
-    let res = res.unwrap_or_else(|e| {
-        let mut r = String::new();
-        _ = e.pretty_print(&mut r, db, span_formatter, def.module(db).krate().edition(db));
-        r
-    });
+    let res = res.unwrap_or_else(|e| render_const_eval_error(db, e, edition));
     let duration = Instant::now() - start_time;
     Some((duration, res))
 }
+
+pub(crate) fn render_const_eval_error(
+    db: &RootDatabase,
+    e: ConstEvalError,
+    edition: Edition,
+) -> String {
+    let span_formatter = |file_id, text_range: TextRange| {
+        let path = &db
+            .source_root(db.file_source_root(file_id))
+            .path_for_file(&file_id)
+            .map(|x| x.to_string());
+        let path = path.as_deref().unwrap_or("<unknown file>");
+        match db.line_index(file_id).try_line_col(text_range.start()) {
+            Some(line_col) => format!("file://{path}:{}:{}", line_col.line + 1, line_col.col),
+            None => format!("file://{path} range {text_range:?}"),
+        }
+    };
+    let mut r = String::new();
+    _ = e.pretty_print(&mut r, db, span_formatter, edition);
+    r
+}
diff --git a/src/tools/rust-analyzer/crates/rust-analyzer/src/cli/analysis_stats.rs b/src/tools/rust-analyzer/crates/rust-analyzer/src/cli/analysis_stats.rs
@@ -331,8 +331,8 @@ impl flags::AnalysisStats {
         let mut fail = 0;
         for &b in bodies {
             let res = match b {
-                DefWithBody::Const(c) => c.render_eval(db, Edition::LATEST),
-                DefWithBody::Static(s) => s.render_eval(db, Edition::LATEST),
+                DefWithBody::Const(c) => c.eval(db),
+                DefWithBody::Static(s) => s.eval(db),
                 _ => continue,
             };
             all += 1;
