Merge pull request #14087 from ethereum/better-error-for-invalid-call

Better error message when trying to call things that are not functions

libsolidity/analysis/TypeChecker.cpp

@@ -2847,7 +2847,11 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 	}
 
 	default:
-		m_errorReporter.fatalTypeError(5704_error, _functionCall.location(), "Type is not callable");
+		m_errorReporter.fatalTypeError(
+			5704_error,
+			_functionCall.location(),
+			capitalized(Type::categoryName(expressionType->category())) + " is not callable."
+		);
 		// Unreachable, because fatalTypeError throws. We don't set kind, but that's okay because the switch below
 		// is never reached. And, even if it was, SetOnce would trigger an assertion violation and not UB.
 		funcCallAnno.isPure = argumentsArePure;

libsolidity/ast/Types.cpp

@@ -294,6 +294,35 @@ Type const* Type::commonType(Type const* _a, Type const* _b)
 		return nullptr;
 }
 
+char const* Type::categoryName(Type::Category _category)
+{
+	switch (_category)
+	{
+	case Category::Address: return "address";
+	case Category::Integer: return "integer";
+	case Category::RationalNumber: return "rational number literal";
+	case Category::StringLiteral: return "string literal";
+	case Category::Bool: return "boolean";
+	case Category::FixedPoint: return "fixed-point number";
+	case Category::Array: return "array";
+	case Category::ArraySlice: return "array slice";
+	case Category::FixedBytes: return "fixed-size byte array";
+	case Category::Contract: return "contract";
+	case Category::Struct: return "struct";
+	case Category::Function: return "function";
+	case Category::Enum: return "enum";
+	case Category::UserDefinedValueType: return "user-defined value type";
+	case Category::Tuple: return "tuple";
+	case Category::Mapping: return "mapping";
+	case Category::TypeType: return "type of a type";
+	case Category::Modifier: return "modifier";
+	case Category::Magic: return "magic variable";
+	case Category::Module: return "module";
+	case Category::InaccessibleDynamic: return "inaccessible dynamic value";
+	}
+	util::unreachable();
+}
+
 MemberList const& Type::members(ASTNode const* _currentScope) const
 {
 	if (!m_members[_currentScope])

libsolidity/ast/Types.h

@@ -174,9 +174,26 @@ public:
 
 	enum class Category
 	{
-		Address, Integer, RationalNumber, StringLiteral, Bool, FixedPoint, Array, ArraySlice,
-		FixedBytes, Contract, Struct, Function, Enum, UserDefinedValueType, Tuple,
-		Mapping, TypeType, Modifier, Magic, Module,
+		Address,
+		Integer,
+		RationalNumber,
+		StringLiteral,
+		Bool,
+		FixedPoint,
+		Array,
+		ArraySlice,
+		FixedBytes,
+		Contract,
+		Struct,
+		Function,
+		Enum,
+		UserDefinedValueType,
+		Tuple,
+		Mapping,
+		TypeType,
+		Modifier,
+		Magic,
+		Module,
 		InaccessibleDynamic
 	};
 
@@ -184,6 +201,8 @@ public:
 	static Type const* commonType(Type const* _a, Type const* _b);
 
 	virtual Category category() const = 0;
+	static char const* categoryName(Type::Category _category);
+
 	/// @returns a valid solidity identifier such that two types should compare equal if and
 	/// only if they have the same identifier.
 	/// The identifier should start with "t_".

libsolutil/StringUtils.h

@@ -160,6 +160,15 @@ inline std::string toLower(std::string _s)
 	return _s;
 }
 
+/// Returns a copy of the string with the first character converted to its uppercase equivalent.
+/// Uses the classic "C" locale semantics.
+inline std::string capitalized(std::string _s)
+{
+	if (_s.size() > 0)
+		_s[0] = toUpper(_s[0]);
+	return _s;
+}
+
 /// Checks whether _c is a decimal digit character. It uses the classic "C" locale semantics.
 /// @param _c character to be checked
 /// @return true if _c is a decimal digit character, false otherwise

test/libsolidity/syntaxTests/functionCalls/enum_value_not_callable.sol

@@ -0,0 +1,7 @@
+enum E { A, B, C }
+
+contract C {
+    uint a = E.B(1000);
+}
+// ----
+// TypeError 5704: (46-55): Enum is not callable.

test/libsolidity/syntaxTests/functionCalls/int_not_callable.sol

@@ -5,4 +5,4 @@ contract C
     }
 }
 // ----
-// TypeError 5704: (53-60): Type is not callable
+// TypeError 5704: (53-60): Rational number literal is not callable.

test/libsolidity/syntaxTests/functionCalls/magic_not_callable.sol

@@ -0,0 +1,5 @@
+contract C {
+    uint a = msg(1000);
+}
+// ----
+// TypeError 5704: (26-35): Magic variable is not callable.

test/libsolidity/syntaxTests/functionCalls/mapping_not_callable.sol

@@ -0,0 +1,6 @@
+contract C {
+    mapping (uint => uint) m;
+    uint a = m(1000);
+}
+// ----
+// TypeError 5704: (56-63): Mapping is not callable.

test/libsolidity/syntaxTests/functionCalls/modifier_not_callable.sol

@@ -0,0 +1,7 @@
+contract C {
+    uint a = m(1000);
+
+    modifier m(uint) { _; }
+}
+// ----
+// TypeError 5704: (26-33): Modifier is not callable.

test/libsolidity/syntaxTests/functionCalls/module_not_callable.sol

@@ -0,0 +1,9 @@
+==== Source: A.sol ====
+==== Source: B.sol ====
+import "A.sol" as A;
+
+contract C {
+    uint a = A(1000);
+}
+// ----
+// TypeError 5704: (B.sol:48-55): Module is not callable.

test/libsolidity/syntaxTests/functionCalls/this_not_callable.sol

@@ -6,4 +6,4 @@ contract C {
     }
 }
 // ----
-// TypeError 5704: (72-78): Type is not callable
+// TypeError 5704: (72-78): Contract is not callable.

test/libsolidity/syntaxTests/nameAndTypeResolution/462_callable_crash.sol

@@ -6,4 +6,4 @@ contract C {
     }
 }
 // ----
-// TypeError 5704: (90-108): Type is not callable
+// TypeError 5704: (90-108): Rational number literal is not callable.

test/libsolidity/syntaxTests/nameAndTypeResolution/492_do_not_crash_on_not_lvalue.sol

@@ -6,4 +6,4 @@ contract C {
     }
 }
 // ----
-// TypeError 5704: (153-157): Type is not callable
+// TypeError 5704: (153-157): Mapping is not callable.

test/libsolidity/syntaxTests/scoping/state_variable_function_conflict_former_crash.sol

@@ -11,4 +11,4 @@ contract SomeContract {
 }
 // ----
 // DeclarationError 2333: (106-145): Identifier already declared.
-// TypeError 5704: (185-195): Type is not callable
+// TypeError 5704: (185-195): Integer is not callable.

test/libsolidity/syntaxTests/tupleAssignments/double_storage_crash.sol

@@ -7,4 +7,4 @@ contract CrashContract {
        }
 }
 // ----
-// TypeError 5704: (170-177): Type is not callable
+// TypeError 5704: (170-177): Rational number literal is not callable.

test/libsolidity/syntaxTests/types/function_call_fail.sol

@@ -4,4 +4,4 @@ contract C {
     }
 }
 // ----
-// TypeError 5704: (59-63): Type is not callable
+// TypeError 5704: (59-63): Rational number literal is not callable.