Extend reported unsafe operations

We add union fields access (in both expressions and patterns) and inline assembly.

That completes the unsafe check (there are some other unsafe things but they are unstable), and so also opens the door to reporting unused unsafe without annoying people about their not-unused unsafe blocks.

Author: ChayimFriedman2

crates/hir-def/src/body.rs

@@ -408,7 +408,8 @@ impl Body {
                     f(else_branch);
                 }
             }
-            Expr::Let { expr, .. } => {
+            Expr::Let { expr, pat } => {
+                self.walk_exprs_in_pat(*pat, &mut f);
                 f(*expr);
             }
             Expr::Block { statements, tail, .. }
@@ -444,7 +445,10 @@ impl Body {
             }
             Expr::Match { expr, arms } => {
                 f(*expr);
-                arms.iter().map(|arm| arm.expr).for_each(f);
+                arms.iter().for_each(|arm| {
+                    f(arm.expr);
+                    self.walk_exprs_in_pat(arm.pat, &mut f);
+                });
             }
             Expr::Break { expr, .. }
             | Expr::Return { expr }
@@ -505,6 +509,131 @@ impl Body {
         }
     }
 
+    pub fn walk_child_exprs_without_pats(&self, expr_id: ExprId, mut f: impl FnMut(ExprId)) {
+        let expr = &self[expr_id];
+        match expr {
+            Expr::Continue { .. }
+            | Expr::Const(_)
+            | Expr::Missing
+            | Expr::Path(_)
+            | Expr::OffsetOf(_)
+            | Expr::Literal(_)
+            | Expr::Underscore => {}
+            Expr::InlineAsm(it) => it.operands.iter().for_each(|(_, op)| match op {
+                AsmOperand::In { expr, .. }
+                | AsmOperand::Out { expr: Some(expr), .. }
+                | AsmOperand::InOut { expr, .. } => f(*expr),
+                AsmOperand::SplitInOut { in_expr, out_expr, .. } => {
+                    f(*in_expr);
+                    if let Some(out_expr) = out_expr {
+                        f(*out_expr);
+                    }
+                }
+                AsmOperand::Out { expr: None, .. }
+                | AsmOperand::Const(_)
+                | AsmOperand::Label(_)
+                | AsmOperand::Sym(_) => (),
+            }),
+            Expr::If { condition, then_branch, else_branch } => {
+                f(*condition);
+                f(*then_branch);
+                if let &Some(else_branch) = else_branch {
+                    f(else_branch);
+                }
+            }
+            Expr::Let { expr, .. } => {
+                f(*expr);
+            }
+            Expr::Block { statements, tail, .. }
+            | Expr::Unsafe { statements, tail, .. }
+            | Expr::Async { statements, tail, .. } => {
+                for stmt in statements.iter() {
+                    match stmt {
+                        Statement::Let { initializer, else_branch, .. } => {
+                            if let &Some(expr) = initializer {
+                                f(expr);
+                            }
+                            if let &Some(expr) = else_branch {
+                                f(expr);
+                            }
+                        }
+                        Statement::Expr { expr: expression, .. } => f(*expression),
+                        Statement::Item(_) => (),
+                    }
+                }
+                if let &Some(expr) = tail {
+                    f(expr);
+                }
+            }
+            Expr::Loop { body, .. } => f(*body),
+            Expr::Call { callee, args, .. } => {
+                f(*callee);
+                args.iter().copied().for_each(f);
+            }
+            Expr::MethodCall { receiver, args, .. } => {
+                f(*receiver);
+                args.iter().copied().for_each(f);
+            }
+            Expr::Match { expr, arms } => {
+                f(*expr);
+                arms.iter().map(|arm| arm.expr).for_each(f);
+            }
+            Expr::Break { expr, .. }
+            | Expr::Return { expr }
+            | Expr::Yield { expr }
+            | Expr::Yeet { expr } => {
+                if let &Some(expr) = expr {
+                    f(expr);
+                }
+            }
+            Expr::Become { expr } => f(*expr),
+            Expr::RecordLit { fields, spread, .. } => {
+                for field in fields.iter() {
+                    f(field.expr);
+                }
+                if let &Some(expr) = spread {
+                    f(expr);
+                }
+            }
+            Expr::Closure { body, .. } => {
+                f(*body);
+            }
+            Expr::BinaryOp { lhs, rhs, .. } => {
+                f(*lhs);
+                f(*rhs);
+            }
+            Expr::Range { lhs, rhs, .. } => {
+                if let &Some(lhs) = rhs {
+                    f(lhs);
+                }
+                if let &Some(rhs) = lhs {
+                    f(rhs);
+                }
+            }
+            Expr::Index { base, index, .. } => {
+                f(*base);
+                f(*index);
+            }
+            Expr::Field { expr, .. }
+            | Expr::Await { expr }
+            | Expr::Cast { expr, .. }
+            | Expr::Ref { expr, .. }
+            | Expr::UnaryOp { expr, .. }
+            | Expr::Box { expr } => {
+                f(*expr);
+            }
+            Expr::Tuple { exprs, .. } => exprs.iter().copied().for_each(f),
+            Expr::Array(a) => match a {
+                Array::ElementList { elements, .. } => elements.iter().copied().for_each(f),
+                Array::Repeat { initializer, repeat } => {
+                    f(*initializer);
+                    f(*repeat)
+                }
+            },
+            &Expr::Assignment { target: _, value } => f(value),
+        }
+    }
+
     pub fn walk_exprs_in_pat(&self, pat_id: PatId, f: &mut impl FnMut(ExprId)) {
         self.walk_pats(pat_id, &mut |pat| {
             if let Pat::Expr(expr) | Pat::ConstBlock(expr) = self[pat] {

crates/hir-ty/src/diagnostics.rs

@@ -9,5 +9,5 @@ pub use crate::diagnostics::{
     expr::{
         record_literal_missing_fields, record_pattern_missing_fields, BodyValidationDiagnostic,
     },
-    unsafe_check::{missing_unsafe, unsafe_expressions, UnsafeExpr},
+    unsafe_check::{missing_unsafe, unsafe_expressions, InsideUnsafeBlock, UnsafetyReason},
 };