Add HighlightTag::Operator, use it for unsafe deref. Move unsafe validation to its own file

crates/ra_hir_ty/src/unsafe_validation.rs

@@ -0,0 +1,63 @@
+//! Provides validations for unsafe code. Currently checks if unsafe functions are missing
+//! unsafe blocks.
+
+use std::sync::Arc;
+
+use hir_def::FunctionId;
+use hir_expand::diagnostics::DiagnosticSink;
+
+use crate::{
+    db::HirDatabase, diagnostics::MissingUnsafe, expr::unsafe_expressions, InferenceResult,
+};
+
+pub use hir_def::{
+    body::{
+        scope::{ExprScopes, ScopeEntry, ScopeId},
+        Body, BodySourceMap, ExprPtr, ExprSource, PatPtr, PatSource,
+    },
+    expr::{
+        ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal, LogicOp,
+        MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement, UnaryOp,
+    },
+    LocalFieldId, VariantId,
+};
+
+pub struct UnsafeValidator<'a, 'b: 'a> {
+    func: FunctionId,
+    infer: Arc<InferenceResult>,
+    sink: &'a mut DiagnosticSink<'b>,
+}
+
+impl<'a, 'b> UnsafeValidator<'a, 'b> {
+    pub fn new(
+        func: FunctionId,
+        infer: Arc<InferenceResult>,
+        sink: &'a mut DiagnosticSink<'b>,
+    ) -> UnsafeValidator<'a, 'b> {
+        UnsafeValidator { func, infer, sink }
+    }
+
+    pub fn validate_body(&mut self, db: &dyn HirDatabase) {
+        let def = self.func.into();
+        let unsafe_expressions = unsafe_expressions(db, self.infer.as_ref(), def);
+        let func_data = db.function_data(self.func);
+        if func_data.is_unsafe
+            || unsafe_expressions
+                .iter()
+                .filter(|unsafe_expr| !unsafe_expr.inside_unsafe_block)
+                .count()
+                == 0
+        {
+            return;
+        }
+
+        let (_, body_source) = db.body_with_source_map(def);
+        for unsafe_expr in unsafe_expressions {
+            if !unsafe_expr.inside_unsafe_block {
+                if let Ok(in_file) = body_source.as_ref().expr_syntax(unsafe_expr.expr) {
+                    self.sink.push(MissingUnsafe { file: in_file.file_id, expr: in_file.value })
+                }
+            }
+        }
+    }
+}