From 044058276ea27b3d43622b28416ad4dc41091a31 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Fri, 30 Jun 2017 16:37:08 +0200
Subject: [PATCH] Warn about callcode.

---
 Changelog.md                                  |  1 +
 libsolidity/analysis/StaticAnalyzer.cpp       |  8 ++++++
 .../SolidityNameAndTypeResolution.cpp         | 27 ++++++++++++++++++-
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/Changelog.md b/Changelog.md
index 8b44934d1..4f224d5b1 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -16,6 +16,7 @@ Features:
  * Code Generator: Added the Whiskers template system.
  * Remove obsolete Why3 output.
  * Type Checker: Enforce strict UTF-8 validation.
+ * Static Analyzer: Warn about deprecation of ``callcode``.
 
 Bugfixes:
  * Code generator: Use ``REVERT`` instead of ``INVALID`` for generated input validation routines.
diff --git a/libsolidity/analysis/StaticAnalyzer.cpp b/libsolidity/analysis/StaticAnalyzer.cpp
index 375e9bdea..b1b31163f 100644
--- a/libsolidity/analysis/StaticAnalyzer.cpp
+++ b/libsolidity/analysis/StaticAnalyzer.cpp
@@ -123,6 +123,14 @@ bool StaticAnalyzer::visit(MemberAccess const& _memberAccess)
 					"\"msg.value\" used in non-payable function. Do you want to add the \"payable\" modifier to this function?"
 				);
 
+	if (_memberAccess.memberName() == "callcode")
+		if (auto const* type = dynamic_cast<FunctionType const*>(_memberAccess.annotation().type.get()))
+			if (type->kind() == FunctionType::Kind::BareCallCode)
+				m_errorReporter.warning(
+					_memberAccess.location(),
+					"\"callcode\" has been deprecated in favour of \"delegatecall\"."
+				);
+
 	return true;
 }
 
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index 169b33d15..d0aee3d0c 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -4679,7 +4679,7 @@ BOOST_AUTO_TEST_CASE(unused_return_value_callcode)
 			}
 		}
 	)";
-	CHECK_WARNING(text, "Return value of low-level calls not used");
+	CHECK_WARNING_ALLOW_MULTI(text, "Return value of low-level calls not used");
 }
 
 BOOST_AUTO_TEST_CASE(unused_return_value_delegatecall)
@@ -4694,6 +4694,31 @@ BOOST_AUTO_TEST_CASE(unused_return_value_delegatecall)
 	CHECK_WARNING(text, "Return value of low-level calls not used");
 }
 
+BOOST_AUTO_TEST_CASE(warn_about_callcode)
+{
+	char const* text = R"(
+		contract test {
+			function f() {
+				var x = address(0x12).callcode;
+				x;
+			}
+		}
+	)";
+	CHECK_WARNING(text, "\"callcode\" has been deprecated in favour");
+}
+
+BOOST_AUTO_TEST_CASE(no_warn_about_callcode_as_local)
+{
+	char const* text = R"(
+		contract test {
+			function callcode() {
+				var x = this.callcode;
+			}
+		}
+	)";
+	CHECK_SUCCESS_NO_WARNINGS(text);
+}
+
 BOOST_AUTO_TEST_CASE(modifier_without_underscore)
 {
 	char const* text = R"(