Merge pull request #4671 from ethereum/mappingTupleAssignment

Disallow assignments to mappings within tuple assignments; allow for local variables.

8 files changed, 144 insertions, 12 deletions

diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
index 45a56b22..066e97e6 100644
--- a/test/libsolidity/SolidityEndToEndTest.cpp
+++ b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -1478,6 +1478,73 @@ BOOST_AUTO_TEST_CASE(multi_level_mapping)
 	testContractAgainstCpp("f(uint256,uint256,uint256)", f, u256(5), u256(4), u256(0));
 }
 
+BOOST_AUTO_TEST_CASE(mapping_local_assignment)
+{
+	char const* sourceCode = R"(
+		contract test {
+			mapping(uint8 => uint8) m1;
+			mapping(uint8 => uint8) m2;
+			function f() public returns (uint8, uint8, uint8, uint8) {
+				mapping(uint8 => uint8) storage m = m1;
+				m[1] = 42;
+
+				m = m2;
+				m[2] = 21;
+
+				return (m1[1], m1[2], m2[1], m2[2]);
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+
+	ABI_CHECK(callContractFunction("f()"), encodeArgs(byte(42), byte(0), byte(0), byte(21)));
+}
+
+BOOST_AUTO_TEST_CASE(mapping_local_tuple_assignment)
+{
+	char const* sourceCode = R"(
+		contract test {
+			mapping(uint8 => uint8) m1;
+			mapping(uint8 => uint8) m2;
+			function f() public returns (uint8, uint8, uint8, uint8) {
+				mapping(uint8 => uint8) storage m = m1;
+				m[1] = 42;
+
+				uint8 v;
+				(m, v) = (m2, 21);
+				m[2] = v;
+
+				return (m1[1], m1[2], m2[1], m2[2]);
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+
+	ABI_CHECK(callContractFunction("f()"), encodeArgs(byte(42), byte(0), byte(0), byte(21)));
+}
+
+BOOST_AUTO_TEST_CASE(mapping_local_compound_assignment)
+{
+	char const* sourceCode = R"(
+		contract test {
+			mapping(uint8 => uint8) m1;
+			mapping(uint8 => uint8) m2;
+			function f() public returns (uint8, uint8, uint8, uint8) {
+				mapping(uint8 => uint8) storage m = m1;
+				m[1] = 42;
+
+				(m = m2)[2] = 21;
+
+				return (m1[1], m1[2], m2[1], m2[2]);
+			}
+		}
+	)";
+	compileAndRun(sourceCode);
+
+	ABI_CHECK(callContractFunction("f()"), encodeArgs(byte(42), byte(0), byte(0), byte(21)));
+}
+
+
 BOOST_AUTO_TEST_CASE(structs)
 {
 	char const* sourceCode = R"(
diff --git a/test/libsolidity/syntaxTests/nameAndTypeResolution/016_assignment_to_mapping.sol b/test/libsolidity/syntaxTests/nameAndTypeResolution/016_assignment_to_mapping.sol
deleted file mode 100644
index 27b1ea96..00000000
--- a/test/libsolidity/syntaxTests/nameAndTypeResolution/016_assignment_to_mapping.sol
+++ /dev/null
@@ -1,12 +0,0 @@
-contract test {
-    struct str {
-        mapping(uint=>uint) map;
-    }
-    str data;
-    function fun() public {
-        mapping(uint=>uint) storage a = data.map;
-        data.map = a;
-    }
-}
-// ----
-// TypeError: (172-184): Mappings cannot be assigned to.
diff --git a/test/libsolidity/syntaxTests/types/mapping/assignment_local.sol b/test/libsolidity/syntaxTests/types/mapping/assignment_local.sol
new file mode 100644
index 00000000..a329c91e
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/assignment_local.sol
@@ -0,0 +1,11 @@
+contract test {
+    mapping(uint=>uint) map;
+    function fun() public view {
+        mapping(uint=>uint) storage a = map;
+        mapping(uint=>uint) storage b = map;
+        b = a;
+        (b) = a;
+        (b, b) = (a, a);
+    }
+}
+// ----
diff --git a/test/libsolidity/syntaxTests/types/mapping/assignment_state_variable.sol b/test/libsolidity/syntaxTests/types/mapping/assignment_state_variable.sol
new file mode 100644
index 00000000..1323afe6
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/assignment_state_variable.sol
@@ -0,0 +1,14 @@
+contract test {
+    mapping(uint=>uint) map;
+    function fun() public {
+        mapping(uint=>uint) storage a = map;
+        map = a;
+        (map) = a;
+        (map, map) = (a, a);
+    }
+}
+// ----
+// TypeError: (126-129): Mappings cannot be assigned to.
+// TypeError: (144-147): Mappings cannot be assigned to.
+// TypeError: (163-166): Mappings cannot be assigned to.
+// TypeError: (168-171): Mappings cannot be assigned to.
diff --git a/test/libsolidity/syntaxTests/types/mapping/assignment_struct.sol b/test/libsolidity/syntaxTests/types/mapping/assignment_struct.sol
new file mode 100644
index 00000000..b89241ed
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/assignment_struct.sol
@@ -0,0 +1,17 @@
+contract test {
+    struct str {
+        mapping(uint=>uint) map;
+    }
+    str data;
+    function fun() public {
+        mapping(uint=>uint) storage a = data.map;
+        data.map = a;
+        (data.map) = a;
+        (data.map, data.map) = (a, a);
+    }
+}
+// ----
+// TypeError: (172-180): Mappings cannot be assigned to.
+// TypeError: (195-203): Mappings cannot be assigned to.
+// TypeError: (219-227): Mappings cannot be assigned to.
+// TypeError: (229-237): Mappings cannot be assigned to.
diff --git a/test/libsolidity/syntaxTests/types/mapping/mapping_return_external.sol b/test/libsolidity/syntaxTests/types/mapping/mapping_return_external.sol
new file mode 100644
index 00000000..85121241
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/mapping_return_external.sol
@@ -0,0 +1,7 @@
+contract C {
+    function f() external pure returns (mapping(uint=>uint) storage m) {
+    }
+}
+// ----
+// TypeError: (53-82): Type is required to live outside storage.
+// TypeError: (53-82): Internal or recursive type is not allowed for public or external functions.
diff --git a/test/libsolidity/syntaxTests/types/mapping/mapping_return_internal.sol b/test/libsolidity/syntaxTests/types/mapping/mapping_return_internal.sol
new file mode 100644
index 00000000..a46003f8
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/mapping_return_internal.sol
@@ -0,0 +1,21 @@
+// This should be allowed in a future release.
+contract C {
+    mapping(uint=>uint) m;
+    function f() internal view returns (mapping(uint=>uint) storage) {
+        return m;
+    }
+    function g() private view returns (mapping(uint=>uint) storage) {
+        return m;
+    }
+    function h() internal view returns (mapping(uint=>uint) storage r) {
+        r = m;
+    }
+    function i() private view returns (mapping(uint=>uint) storage r) {
+        (r,r) = (m,m);
+    }
+}
+// ----
+// TypeError: (127-146): Type is required to live outside storage.
+// TypeError: (221-240): Type is required to live outside storage.
+// TypeError: (316-345): Type is required to live outside storage.
+// TypeError: (409-438): Type is required to live outside storage.
diff --git a/test/libsolidity/syntaxTests/types/mapping/mapping_return_public.sol b/test/libsolidity/syntaxTests/types/mapping/mapping_return_public.sol
new file mode 100644
index 00000000..383fa797
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/mapping_return_public.sol
@@ -0,0 +1,7 @@
+contract C {
+    function f() public pure returns (mapping(uint=>uint) storage m) {
+    }
+}
+// ----
+// TypeError: (51-80): Type is required to live outside storage.
+// TypeError: (51-80): Internal or recursive type is not allowed for public or external functions.