From 9c7b1e9c3f606925ba160686214abec4eee8adc9 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Tue, 23 Feb 2021 10:57:49 +0100
Subject: [PATCH] Detect assignment to function in inline assembly.

---
 libyul/AsmAnalysis.cpp                                 |  8 +++-----
 .../inlineAssembly/invalid/assignment_to_function.sol  | 10 ++++++++++
 2 files changed, 13 insertions(+), 5 deletions(-)
 create mode 100644 test/libsolidity/syntaxTests/inlineAssembly/invalid/assignment_to_function.sol

diff --git a/libyul/AsmAnalysis.cpp b/libyul/AsmAnalysis.cpp
index 75428fe5b..fdd4c19ed 100644
--- a/libyul/AsmAnalysis.cpp
+++ b/libyul/AsmAnalysis.cpp
@@ -530,11 +530,9 @@ void AsmAnalyzer::checkAssignment(Identifier const& _variable, YulString _valueT
 	bool found = false;
 	if (Scope::Identifier const* var = m_currentScope->lookup(_variable.name))
 	{
-		// Check that it is a variable.
-		// This can also hold a function, but that is caught by error 6041.
-		yulAssert(holds_alternative<Scope::Variable>(*var), "Assignment requires variable.");
-
-		if (!m_activeVariables.count(&std::get<Scope::Variable>(*var)))
+		if (!holds_alternative<Scope::Variable>(*var))
+			m_errorReporter.typeError(2657_error, _variable.location, "Assignment requires variable.");
+		else if (!m_activeVariables.count(&std::get<Scope::Variable>(*var)))
 			m_errorReporter.declarationError(
 				1133_error,
 				_variable.location,
diff --git a/test/libsolidity/syntaxTests/inlineAssembly/invalid/assignment_to_function.sol b/test/libsolidity/syntaxTests/inlineAssembly/invalid/assignment_to_function.sol
new file mode 100644
index 000000000..9ce487295
--- /dev/null
+++ b/test/libsolidity/syntaxTests/inlineAssembly/invalid/assignment_to_function.sol
@@ -0,0 +1,10 @@
+contract C {
+    function f() public pure {
+        assembly {
+            function f() {}
+            f := 1
+        }
+    }
+}
+// ----
+// TypeError 2657: (103-104): Assignment requires variable.