From 114dc2eecaff3262472645f19f961971ee448de5 Mon Sep 17 00:00:00 2001
From: Alexis <alexis.challande@trailofbits.com>
Date: Mon, 8 Apr 2024 11:43:42 +0200
Subject: [PATCH] Fix #2266 where the type of functions when used as RValues
 was not properly printed.

---
 slither/slithir/operations/assignment.py         | 13 +++++++++++--
 .../test_data/test_printer_slithir/bug-2266.sol  | 13 +++++++++++++
 tests/e2e/printers/test_printers.py              | 16 ++++++++++++++++
 3 files changed, 40 insertions(+), 2 deletions(-)
 create mode 100644 tests/e2e/printers/test_data/test_printer_slithir/bug-2266.sol

diff --git a/slither/slithir/operations/assignment.py b/slither/slithir/operations/assignment.py
index 1f29ceb7b1..ab6637faa0 100644
--- a/slither/slithir/operations/assignment.py
+++ b/slither/slithir/operations/assignment.py
@@ -45,10 +45,19 @@ def rvalue(self) -> Union[RVALUE, Function, TupleVariable]:
 
     def __str__(self) -> str:
         lvalue = self.lvalue
+
+        # When rvalues are functions, we want to properly display their return type
+        # Fix: https://github.com/crytic/slither/issues/2266
+        if isinstance(self.rvalue.type, list):
+            rvalue_type = ",".join(f"{rvalue_type}" for rvalue_type in self.rvalue.type)
+        else:
+            rvalue_type = f"{self.rvalue.type}"
+
         assert lvalue
         if lvalue and isinstance(lvalue, ReferenceVariable):
             points = lvalue.points_to
             while isinstance(points, ReferenceVariable):
                 points = points.points_to
-            return f"{lvalue}({lvalue.type}) (->{points}) := {self.rvalue}({self.rvalue.type})"
-        return f"{lvalue}({lvalue.type}) := {self.rvalue}({self.rvalue.type})"
+            return f"{lvalue}({lvalue.type}) (->{points}) := {self.rvalue}({rvalue_type})"
+
+        return f"{lvalue}({lvalue.type}) := {self.rvalue}({rvalue_type})"
diff --git a/tests/e2e/printers/test_data/test_printer_slithir/bug-2266.sol b/tests/e2e/printers/test_data/test_printer_slithir/bug-2266.sol
new file mode 100644
index 0000000000..5c11a29141
--- /dev/null
+++ b/tests/e2e/printers/test_data/test_printer_slithir/bug-2266.sol
@@ -0,0 +1,13 @@
+pragma solidity ^0.8.0;
+
+contract A {
+    function add(uint256 a, uint256 b) public returns (uint256) {
+        return a + b;
+    }
+}
+
+contract B is A {
+    function assignFunction() public {
+        function(uint256, uint256) returns (uint256) myFunction = super.add;
+    }
+}
\ No newline at end of file
diff --git a/tests/e2e/printers/test_printers.py b/tests/e2e/printers/test_printers.py
index 26429d3381..b7cd4d3b6b 100644
--- a/tests/e2e/printers/test_printers.py
+++ b/tests/e2e/printers/test_printers.py
@@ -7,6 +7,7 @@
 
 from slither import Slither
 from slither.printers.inheritance.inheritance_graph import PrinterInheritanceGraph
+from slither.printers.summary.slithir import PrinterSlithIR
 
 
 TEST_DATA_DIR = Path(__file__).resolve().parent / "test_data"
@@ -34,3 +35,18 @@ def test_inheritance_printer(solc_binary_path) -> None:
 
     assert counter["B -> A"] == 2
     assert counter["C -> A"] == 1
+
+
+def test_slithir_printer(solc_binary_path) -> None:
+    solc_path = solc_binary_path("0.8.0")
+    standard_json = SolcStandardJson()
+    standard_json.add_source_file(
+        Path(TEST_DATA_DIR, "test_printer_slithir", "bug-2266.sol").as_posix()
+    )
+    compilation = CryticCompile(standard_json, solc=solc_path)
+    slither = Slither(compilation)
+
+    printer = PrinterSlithIR(slither, logger=None)
+    output = printer.output("test_printer_slithir.dot")
+
+    assert "slither.core.solidity_types" not in output.data["description"]