Enforce the rules for arithmetic operations

This adds test cases and enforces the type rules for ArithmeticOrLogical
Operators.

2 files changed, 82 insertions, 1 deletions

diff --git a/gcc/rust/typecheck/rust-hir-type-check-expr.h b/gcc/rust/typecheck/rust-hir-type-check-expr.h
index c47e0ec..419b911 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-expr.h
+++ b/gcc/rust/typecheck/rust-hir-type-check-expr.h
@@ -367,8 +367,61 @@ public:
   {
     auto lhs = TypeCheckExpr::Resolve (expr.get_lhs ());
     auto rhs = TypeCheckExpr::Resolve (expr.get_rhs ());
+    auto combined = lhs->combine (rhs);
 
-    infered = lhs->combine (rhs);
+    // https://doc.rust-lang.org/reference/expressions/operator-expr.html#arithmetic-and-logical-binary-operators
+    switch (expr.get_expr_type ())
+      {
+	// integers or floats
+      case HIR::ArithmeticOrLogicalExpr::ADD:
+      case HIR::ArithmeticOrLogicalExpr::SUBTRACT:
+      case HIR::ArithmeticOrLogicalExpr::MULTIPLY:
+      case HIR::ArithmeticOrLogicalExpr::DIVIDE:
+	case HIR::ArithmeticOrLogicalExpr::MODULUS: {
+	  bool valid = (combined->get_kind () == TyTy::TypeKind::INT)
+		       || (combined->get_kind () == TyTy::TypeKind::UINT)
+		       || (combined->get_kind () == TyTy::TypeKind::FLOAT);
+	  if (!valid)
+	    {
+	      rust_error_at (expr.get_locus (), "cannot apply operator to %s",
+			     combined->as_string ().c_str ());
+	      return;
+	    }
+	}
+	break;
+
+	// integers or bools
+      case HIR::ArithmeticOrLogicalExpr::BITWISE_AND:
+      case HIR::ArithmeticOrLogicalExpr::BITWISE_OR:
+	case HIR::ArithmeticOrLogicalExpr::BITWISE_XOR: {
+	  bool valid = (combined->get_kind () == TyTy::TypeKind::INT)
+		       || (combined->get_kind () == TyTy::TypeKind::UINT)
+		       || (combined->get_kind () == TyTy::TypeKind::BOOL);
+	  if (!valid)
+	    {
+	      rust_error_at (expr.get_locus (), "cannot apply operator to %s",
+			     combined->as_string ().c_str ());
+	      return;
+	    }
+	}
+	break;
+
+	// integers only
+      case HIR::ArithmeticOrLogicalExpr::LEFT_SHIFT:
+	case HIR::ArithmeticOrLogicalExpr::RIGHT_SHIFT: {
+	  bool valid = (combined->get_kind () == TyTy::TypeKind::INT)
+		       || (combined->get_kind () == TyTy::TypeKind::UINT);
+	  if (!valid)
+	    {
+	      rust_error_at (expr.get_locus (), "cannot apply operator to %s",
+			     combined->as_string ().c_str ());
+	      return;
+	    }
+	}
+	break;
+      }
+
+    infered = combined;
   }
 
   void visit (HIR::ComparisonExpr &expr)
diff --git a/gcc/testsuite/rust.test/compilable/arithmetic_expressions1.rs b/gcc/testsuite/rust.test/compilable/arithmetic_expressions1.rs
new file mode 100644
index 0000000..efc63f5
--- /dev/null
+++ b/gcc/testsuite/rust.test/compilable/arithmetic_expressions1.rs
@@ -0,0 +1,28 @@
+fn main() {
+    let a: i32 = 1;
+    let b: f32 = 5f32;
+    let c: bool = true;
+
+    let a1: i32 = a + 1;
+    let a2: i32 = a - 2;
+    let a3: i32 = a * 3;
+    let a4: i32 = a / 4;
+    let a5: i32 = a % 5;
+
+    let b1: f32 = b + 1f32;
+    let b2: f32 = b - 2f32;
+    let b3: f32 = b * 3f32;
+    let b4: f32 = b / 4f32;
+    // let b5: f32 = b % 5f32;
+
+    let aa1: i32 = a & 1;
+    let aa2: i32 = a | 2;
+    let aa2: i32 = a ^ 3;
+
+    let c1: bool = c & true;
+    let c2: bool = c | false;
+    let c3: bool = c ^ true;
+
+    let aaa1: i32 = a << 1;
+    let aaa2: i32 = a >> 2;
+}