From 6ac12afd0623b9ae7b92123374f67f0b752d494d Mon Sep 17 00:00:00 2001
From: Mathias Baumann <git@supradigital.org>
Date: Tue, 22 Oct 2019 12:26:26 +0200
Subject: [PATCH] Disallow call of same-class-ctor as modifier

---
 Changelog.md                                              | 1 +
 libsolidity/analysis/TypeChecker.cpp                      | 8 +++++---
 .../syntaxTests/modifiers/constructor_as_modifier.sol     | 5 +++++
 3 files changed, 11 insertions(+), 3 deletions(-)
 create mode 100644 test/libsolidity/syntaxTests/modifiers/constructor_as_modifier.sol

diff --git a/Changelog.md b/Changelog.md
index e4baf02db..bcb3966fb 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -8,6 +8,7 @@ Compiler Features:
 
 
 Bugfixes:
+ * Type Checker: Disallow constructor of the same class to be used as modifier
 
 
 
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index b5abe59f4..42b1be500 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -390,11 +390,13 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 	set<Declaration const*> modifiers;
 	for (ASTPointer<ModifierInvocation> const& modifier: _function.modifiers())
 	{
+		auto baseContracts = dynamic_cast<ContractDefinition const&>(*_function.scope()).annotation().linearizedBaseContracts;
+		// Delete first base which is just the main contract itself
+		baseContracts.erase(baseContracts.begin());
+
 		visitManually(
 			*modifier,
-			_function.isConstructor() ?
-			dynamic_cast<ContractDefinition const&>(*_function.scope()).annotation().linearizedBaseContracts :
-			vector<ContractDefinition const*>()
+			_function.isConstructor() ? baseContracts : vector<ContractDefinition const*>()
 		);
 		Declaration const* decl = &dereference(*modifier->name());
 		if (modifiers.count(decl))
diff --git a/test/libsolidity/syntaxTests/modifiers/constructor_as_modifier.sol b/test/libsolidity/syntaxTests/modifiers/constructor_as_modifier.sol
new file mode 100644
index 000000000..a65e0e84c
--- /dev/null
+++ b/test/libsolidity/syntaxTests/modifiers/constructor_as_modifier.sol
@@ -0,0 +1,5 @@
+contract C {
+    constructor() C() public {}
+}
+// ----
+// TypeError: (31-34): Referenced declaration is neither modifier nor base class.