Fix error message about accessing storage pointers.

libsolidity/analysis/ControlFlowAnalyzer.cpp

@@ -142,7 +142,7 @@ void ControlFlowAnalyzer::checkUninitializedAccess(CFGNode const* _entry, CFGNod
 				ssl,
 				string("This variable is of storage pointer type and can be ") +
 				(variableOccurrence->kind() == VariableOccurrence::Kind::Return ? "returned" : "accessed") +
-				" without prior assignment."
+				" without prior assignment, which would lead to undefined behaviour."
 			);
 		}
 	}

test/libsolidity/syntaxTests/controlFlow/mappingReturn/named_err.sol

@@ -2,4 +2,4 @@ contract C {
     function f() internal pure returns (mapping(uint=>uint) storage r) { }
 }
 // ----
-// TypeError: (53-82): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (53-82): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/mappingReturn/unnamed_err.sol

@@ -2,4 +2,4 @@ contract C {
     function f() internal pure returns (mapping(uint=>uint) storage) {}
 }
 // ----
-// TypeError: (53-80): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (53-80): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/assembly_err.sol

@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (87-96): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (87-96): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/dowhile_err.sol

@@ -45,12 +45,12 @@ contract C {
     }
 }
 // ----
-// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
 // Warning: (146-151): Unreachable code.
 // Warning: (169-174): Unreachable code.
-// TypeError: (223-234): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (223-234): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
 // Warning: (316-321): Unreachable code.
-// TypeError: (440-451): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (654-665): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (871-882): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (440-451): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (654-665): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (871-882): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
 // Warning: (933-938): Unreachable code.

test/libsolidity/syntaxTests/controlFlow/storageReturn/for_err.sol

@@ -12,5 +12,5 @@ contract C {
     }
 }
 // ----
-// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (182-193): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (182-193): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/if_err.sol

@@ -14,5 +14,5 @@ contract C {
     }
 }
 // ----
-// TypeError: (96-107): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (186-197): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (96-107): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (186-197): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/modifier_err.sol

@@ -18,5 +18,5 @@ contract C {
     }
 }
 // ----
-// TypeError: (249-258): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (367-376): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (249-258): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (367-376): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/short_circuit_err.sol

@@ -13,6 +13,6 @@ contract C {
     }
 }
 // ----
-// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (176-187): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (264-275): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (176-187): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (264-275): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/ternary_err.sol

@@ -9,5 +9,5 @@ contract C {
     }
 }
 // ----
-// TypeError: (96-107): This variable is of storage pointer type and can be returned without prior assignment.
-// TypeError: (200-211): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (96-107): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.
+// TypeError: (200-211): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/storageReturn/while_err.sol

@@ -8,4 +8,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment.
+// TypeError: (87-98): This variable is of storage pointer type and can be returned without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/assembly.sol

@@ -6,4 +6,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (92-116): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (92-116): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/modifier_order_fail.sol

@@ -5,4 +5,4 @@ contract C {
     function f() m1(b) m2(b = s) internal view returns (uint[] storage b) {}
 }
 // ----
-// TypeError: (129-130): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (129-130): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/modifier_post_access.sol

@@ -10,4 +10,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (120-121): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (120-121): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/modifier_pre_access.sol

@@ -10,4 +10,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (120-121): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (120-121): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/smoke.sol

@@ -7,4 +7,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (94-95): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (94-95): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/controlFlow/uninitializedAccess/struct.sol

@@ -8,4 +8,4 @@ contract C {
     }
 }
 // ----
-// TypeError: (109-110): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (109-110): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.

test/libsolidity/syntaxTests/dataLocations/libraries/library_function_with_data_location_fine.sol

@@ -8,9 +8,9 @@ library L {
     function i(uint[] calldata, uint[] storage) external pure returns (S storage x) {return x; }
 }
 // ----
-// TypeError: (197-198): This variable is of storage pointer type and can be accessed without prior assignment.
-// TypeError: (203-204): This variable is of storage pointer type and can be accessed without prior assignment.
-// TypeError: (359-360): This variable is of storage pointer type and can be accessed without prior assignment.
-// TypeError: (365-366): This variable is of storage pointer type and can be accessed without prior assignment.
-// TypeError: (460-461): This variable is of storage pointer type and can be accessed without prior assignment.
-// TypeError: (557-558): This variable is of storage pointer type and can be accessed without prior assignment.
+// TypeError: (197-198): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (203-204): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (359-360): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (365-366): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (460-461): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.
+// TypeError: (557-558): This variable is of storage pointer type and can be accessed without prior assignment, which would lead to undefined behaviour.