Fix panics caused by shifting(hyperledger#1618) (hyperledger#1627)

Fixed the bug where there was no load when the right expression of the
shift calculation is a structure member.

Signed-off-by: yp945 <pan107104@outlook.com>

src/sema/expression/arithmetic.rs

@@ -227,12 +227,19 @@ pub(super) fn shift_left(
     let (right_length, _) = type_bits_and_sign(&right.ty(), &r.loc(), false, ns, diagnostics)?;
 
     let left_type = left.ty().deref_any().clone();
+    let right_type = right.ty().deref_any().clone();
 
     Ok(Expression::ShiftLeft {
         loc: *loc,
         ty: left_type.clone(),
         left: Box::new(left.cast(loc, &left_type, true, ns, diagnostics)?),
-        right: Box::new(cast_shift_arg(loc, right, right_length, &left_type, ns)),
+        right: Box::new(cast_shift_arg(
+            loc,
+            right.cast(loc, &right_type, true, ns, diagnostics)?,
+            right_length,
+            &left_type,
+            ns,
+        )),
     })
 }
 
@@ -252,6 +259,7 @@ pub(super) fn shift_right(
     check_var_usage_expression(ns, &left, &right, symtable);
 
     let left_type = left.ty().deref_any().clone();
+    let right_type = right.ty().deref_any().clone();
     // left hand side may be bytes/int/uint
     // right hand size may be int/uint
     let _ = type_bits_and_sign(&left_type, &l.loc(), true, ns, diagnostics)?;
@@ -261,7 +269,13 @@ pub(super) fn shift_right(
         loc: *loc,
         ty: left_type.clone(),
         left: Box::new(left.cast(loc, &left_type, true, ns, diagnostics)?),
-        right: Box::new(cast_shift_arg(loc, right, right_length, &left_type, ns)),
+        right: Box::new(cast_shift_arg(
+            loc,
+            right.cast(loc, &right_type, true, ns, diagnostics)?,
+            right_length,
+            &left_type,
+            ns,
+        )),
         sign: left_type.is_signed_int(ns),
     })
 }

tests/codegen_testcases/solidity/struct_member_shift.sol

@@ -0,0 +1,29 @@
+// RUN: --target polkadot --emit cfg
+contract c {
+    struct S {
+        uint256 a;
+    }
+	function test1(S memory s) public pure returns (uint256) {
+// CHECK: ty:uint256 %b = (uint256 2 << (load (struct (arg #0) field 0)))
+		uint256 b = 2 << s.a;
+		return b;
+	}
+
+    function test2(S memory s) public pure returns (uint256) {
+// CHECK: ty:uint256 %b = ((load (struct (arg #0) field 0)) << uint256 2)
+		uint256 b = s.a << 2;
+		return b;
+	}
+
+    function test3(S memory s) public pure returns (uint256) {
+// CHECK: ty:uint256 %b = (uint256 2 >> (load (struct (arg #0) field 0)))
+		uint256 b = 2 >> s.a;
+		return b;
+	}
+
+    function test4(S memory s) public pure returns (uint256) {
+// CHECK: ty:uint256 %b = ((load (struct (arg #0) field 0)) >> uint256 2)
+		uint256 b = s.a >> 2;
+		return b;
+	}
+}