Add comparison ops

Author: r41k0u

examples/execve3.py

@@ -30,10 +30,10 @@ def hello_again(ctx: c_void_p) -> c_int64:
 #        if delta < 1000000000:
 #            print("execve called within last second")
 #        last().delete(key)
-    x = True
+    x = 1
     y = False
-    if x:
-        if y:
+    if x > 0:
+        if x < 2:
             print("we prevailed")
         else:
             print("we did not prevail")

pythonbpf/functions_pass.py

@@ -101,8 +101,26 @@ def handle_assign(func, module, builder, stmt, map_sym_tab, local_sym_tab):
 
 def handle_expr(func, module, builder, expr, local_sym_tab, map_sym_tab):
     """Handle expression statements in the function body."""
+    print(f"Handling expression: {ast.dump(expr)}")
+
+    if isinstance(expr, ast.Name):
+        if expr.id in local_sym_tab:
+            var = local_sym_tab[expr.id]
+            val = builder.load(var)
+            return val
+        else:
+            print(f"Undefined variable {expr.id}")
+            return None
+    elif isinstance(expr, ast.Constant):
+        if isinstance(expr.value, int):
+            return ir.Constant(ir.IntType(64), expr.value)
+        elif isinstance(expr.value, bool):
+            return ir.Constant(ir.IntType(1), int(expr.value))
+        else:
+            print("Unsupported constant type")
+            return None
+
     call = expr.value
-    print(f"Handling expression: {ast.dump(call)}")
     if isinstance(call, ast.Call):
         if isinstance(call.func, ast.Name):
             # check for helpers first
@@ -154,6 +172,42 @@ def handle_cond(func, module, builder, cond, local_sym_tab, map_sym_tab):
         else:
             print(f"Undefined variable {cond.id} in condition")
             return None
+    elif isinstance(cond, ast.Compare):
+        lhs = handle_expr(func, module, builder, cond.left,
+                          local_sym_tab, map_sym_tab)
+        if len(cond.ops) != 1 or len(cond.comparators) != 1:
+            print("Unsupported complex comparison")
+            return None
+        rhs = handle_expr(func, module, builder,
+                          cond.comparators[0], local_sym_tab, map_sym_tab)
+        op = cond.ops[0]
+
+        if lhs.type != rhs.type:
+            if isinstance(lhs.type, ir.IntType) and isinstance(rhs.type, ir.IntType):
+                # Extend the smaller type to the larger type
+                if lhs.type.width < rhs.type.width:
+                    lhs = builder.sext(lhs, rhs.type)
+                elif lhs.type.width > rhs.type.width:
+                    rhs = builder.sext(rhs, lhs.type)
+            else:
+                print("Type mismatch in comparison")
+                return None
+
+        if isinstance(op, ast.Eq):
+            return builder.icmp_signed("==", lhs, rhs)
+        elif isinstance(op, ast.NotEq):
+            return builder.icmp_signed("!=", lhs, rhs)
+        elif isinstance(op, ast.Lt):
+            return builder.icmp_signed("<", lhs, rhs)
+        elif isinstance(op, ast.LtE):
+            return builder.icmp_signed("<=", lhs, rhs)
+        elif isinstance(op, ast.Gt):
+            return builder.icmp_signed(">", lhs, rhs)
+        elif isinstance(op, ast.GtE):
+            return builder.icmp_signed(">=", lhs, rhs)
+        else:
+            print("Unsupported comparison operator")
+            return None
     else:
         print("Unsupported condition expression")
         return None