Merge pull request #3498 from ethereum/allowthisfselector

Allow `this.f.selector` to be pure.

3 files changed, 56 insertions, 12 deletions

diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 5b98d979..0611e71d 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -10219,24 +10219,29 @@ BOOST_AUTO_TEST_CASE(function_types_sig)
 {
 	char const* sourceCode = R"(
 		contract C {
-			function f() returns (bytes4) {
+			uint public x;
+			function f() pure returns (bytes4) {
 				return this.f.selector;
 			}
 			function g() returns (bytes4) {
-				function () external returns (bytes4) fun = this.f;
+				function () pure external returns (bytes4) fun = this.f;
 				return fun.selector;
 			}
 			function h() returns (bytes4) {
-				function () external returns (bytes4) fun = this.f;
+				function () pure external returns (bytes4) fun = this.f;
 				var funvar = fun;
 				return funvar.selector;
 			}
+			function i() pure returns (bytes4) {
+				return this.x.selector;
+			}
 		}
 	)";
 	compileAndRun(sourceCode, 0, "C");
 	ABI_CHECK(callContractFunction("f()"), encodeArgs(asString(FixedHash<4>(dev::keccak256("f()")).asBytes())));
 	ABI_CHECK(callContractFunction("g()"), encodeArgs(asString(FixedHash<4>(dev::keccak256("f()")).asBytes())));
 	ABI_CHECK(callContractFunction("h()"), encodeArgs(asString(FixedHash<4>(dev::keccak256("f()")).asBytes())));
+	ABI_CHECK(callContractFunction("i()"), encodeArgs(asString(FixedHash<4>(dev::keccak256("x()")).asBytes())));
 }
 
 BOOST_AUTO_TEST_CASE(constant_string)
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index c4741657..315c7c5f 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -6991,15 +6991,7 @@ BOOST_AUTO_TEST_CASE(function_types_sig)
 	CHECK_ERROR(text, TypeError, "Member \"selector\" not found");
 	text = R"(
 		contract C {
-			function f() view external returns (bytes4) {
-				return this.f.selector;
-			}
-		}
-	)";
-	CHECK_SUCCESS_NO_WARNINGS(text);
-	text = R"(
-		contract C {
-			function f() view external returns (bytes4) {
+			function f() pure external returns (bytes4) {
 				return this.f.selector;
 			}
 		}
diff --git a/test/libsolidity/ViewPureChecker.cpp b/test/libsolidity/ViewPureChecker.cpp
index e91e713c..3a03c877 100644
--- a/test/libsolidity/ViewPureChecker.cpp
+++ b/test/libsolidity/ViewPureChecker.cpp
@@ -326,6 +326,53 @@ BOOST_AUTO_TEST_CASE(function_types)
 	CHECK_SUCCESS_NO_WARNINGS(text);
 }
 
+BOOST_AUTO_TEST_CASE(selector)
+{
+	string text = R"(
+		contract C {
+			uint public x;
+			function f() payable public {
+			}
+			function g() pure public returns (bytes4) {
+				return this.f.selector ^ this.x.selector;
+			}
+		}
+	)";
+	CHECK_SUCCESS_NO_WARNINGS(text);
+}
+
+BOOST_AUTO_TEST_CASE(selector_complex)
+{
+	string text = R"(
+		contract C {
+			function f(C c) pure public returns (C) {
+				return c;
+			}
+			function g() pure public returns (bytes4) {
+				// By passing `this`, we read from the state, even if f itself is pure.
+				return f(this).f.selector;
+			}
+		}
+	)";
+	CHECK_ERROR(text, TypeError, "reads from the environment or state and thus requires \"view\"");
+}
+
+BOOST_AUTO_TEST_CASE(selector_complex2)
+{
+	string text = R"(
+		contract C {
+				function f() payable public returns (C) {
+				return this;
+			}
+			function g() pure public returns (bytes4) {
+				C x = C(0x123);
+				return x.f.selector;
+			}
+		}
+	)";
+	CHECK_SUCCESS_NO_WARNINGS(text);
+}
+
 BOOST_AUTO_TEST_CASE(creation)
 {
 	string text = R"(