From eeaf8d94d0f555f3859e368da618f2257bdd695b Mon Sep 17 00:00:00 2001
From: Swastik Baranwal <swstkbaranwal@gmail.com>
Date: Fri, 17 May 2024 02:43:56 +0530
Subject: [PATCH]  checker: disallow invalid ptr operations  (#21515)

---
 vlib/v/checker/infix.v                             |  6 ++++++
 .../tests/disallow_pointer_arithmetic_err.out      | 14 ++++++++++++++
 vlib/v/checker/tests/invalid_op_ptr_err.out        | 14 ++++++++++++++
 vlib/v/checker/tests/invalid_op_ptr_err.vv         |  7 +++++++
 vlib/v/checker/tests/pointer_ops.out               | 14 ++++++++++++++
 5 files changed, 55 insertions(+)
 create mode 100644 vlib/v/checker/tests/invalid_op_ptr_err.out
 create mode 100644 vlib/v/checker/tests/invalid_op_ptr_err.vv

diff --git a/vlib/v/checker/infix.v b/vlib/v/checker/infix.v
index 08d87a2dc..560f14bfa 100644
--- a/vlib/v/checker/infix.v
+++ b/vlib/v/checker/infix.v
@@ -331,6 +331,12 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 				}
 			}
 
+			if ((unwrapped_left_type.is_ptr() && !node.left.is_auto_deref_var())
+				|| (unwrapped_right_type.is_ptr() && !node.right.is_auto_deref_var()))
+				&& node.op !in [.plus, .minus] {
+				c.error('infix `${node.op}` is not defined for pointer values', left_right_pos)
+			}
+
 			if !c.pref.translated && left_sym.kind in [.array, .array_fixed, .map, .struct_] {
 				if left_sym.has_method_with_generic_parent(node.op.str()) {
 					if method := left_sym.find_method_with_generic_parent(node.op.str()) {
diff --git a/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out b/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out
index 2c2a8c0f0..2c67a2ca0 100644
--- a/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out
+++ b/vlib/v/checker/tests/disallow_pointer_arithmetic_err.out
@@ -25,6 +25,13 @@ vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:5:7: error: invalid oper
       |          ~~~~~
     6 |     _ := p * 2 //should be error
     7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:5:7: error: infix `*` is not defined for pointer values
+    3 |     p := &x
+    4 |     _ := p + p //should be error
+    5 |     _ := p * p //should be error
+      |          ~~~~~
+    6 |     _ := p * 2 //should be error
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
 vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:6:7: error: invalid operator `*` to `&int` and `int literal`
     4 |     _ := p + p //should be error
     5 |     _ := p * p //should be error
@@ -32,3 +39,10 @@ vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:6:7: error: invalid oper
       |          ~~~~~
     7 |     _ := p + 5 //OK but only in unsafe block, r is *int
     8 |     _ := p - p //OK even in safe code, but n should be isize
+vlib/v/checker/tests/disallow_pointer_arithmetic_err.vv:6:7: error: infix `*` is not defined for pointer values
+    4 |     _ := p + p //should be error
+    5 |     _ := p * p //should be error
+    6 |     _ := p * 2 //should be error
+      |          ~~~~~
+    7 |     _ := p + 5 //OK but only in unsafe block, r is *int
+    8 |     _ := p - p //OK even in safe code, but n should be isize
diff --git a/vlib/v/checker/tests/invalid_op_ptr_err.out b/vlib/v/checker/tests/invalid_op_ptr_err.out
new file mode 100644
index 000000000..0cf09ded3
--- /dev/null
+++ b/vlib/v/checker/tests/invalid_op_ptr_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/invalid_op_ptr_err.vv:3:6: error: infix `*` is not defined for pointer values
+    1 | num := 10
+    2 | p := &num
+    3 | x := 5 * p
+      |      ~~~~~
+    4 | y := 5 / p
+    5 | dump(x)
+vlib/v/checker/tests/invalid_op_ptr_err.vv:4:6: error: infix `/` is not defined for pointer values
+    2 | p := &num
+    3 | x := 5 * p
+    4 | y := 5 / p
+      |      ~~~~~
+    5 | dump(x)
+    6 | dump(p)
diff --git a/vlib/v/checker/tests/invalid_op_ptr_err.vv b/vlib/v/checker/tests/invalid_op_ptr_err.vv
new file mode 100644
index 000000000..05b88977a
--- /dev/null
+++ b/vlib/v/checker/tests/invalid_op_ptr_err.vv
@@ -0,0 +1,7 @@
+num := 10
+p := &num
+x := 5 * p
+y := 5 / p
+dump(x)
+dump(p)
+dump(y)
diff --git a/vlib/v/checker/tests/pointer_ops.out b/vlib/v/checker/tests/pointer_ops.out
index 6aa773f10..5afb7cff6 100644
--- a/vlib/v/checker/tests/pointer_ops.out
+++ b/vlib/v/checker/tests/pointer_ops.out
@@ -54,6 +54,13 @@ vlib/v/checker/tests/pointer_ops.vv:15:3: error: invalid operator `%` to `&Foo`
       |         ~~~~~~~
    16 |     }
    17 | }
+vlib/v/checker/tests/pointer_ops.vv:15:3: error: infix `%` is not defined for pointer values
+   13 |         _ = p[3]
+   14 |         mut foo := &Foo{}
+   15 |         foo % 3
+      |         ~~~~~~~
+   16 |     }
+   17 | }
 vlib/v/checker/tests/pointer_ops.vv:15:3: error: mismatched types `&Foo` and `int literal`
    13 |         _ = p[3]
    14 |         mut foo := &Foo{}
@@ -117,6 +124,13 @@ vlib/v/checker/tests/pointer_ops.vv:30:3: error: invalid operator `%` to `&Foo`
       |         ~~~~~~~
    31 |     }
    32 | }
+vlib/v/checker/tests/pointer_ops.vv:30:3: error: infix `%` is not defined for pointer values
+   28 |         _ = p[3]
+   29 |         mut foo := &Foo{}
+   30 |         foo % 3
+      |         ~~~~~~~
+   31 |     }
+   32 | }
 vlib/v/checker/tests/pointer_ops.vv:30:3: error: mismatched types `&Foo` and `int literal`
    28 |         _ = p[3]
    29 |         mut foo := &Foo{}
-- 
2.39.5