[isoltest] Add support to query balance.

Author: aarlt

test/libsolidity/SemanticTest.cpp

@@ -62,8 +62,11 @@ SemanticTest::SemanticTest(string const& _filename, langutil::EVMVersion _evmVer
 		{
 			{"smoke",
 				{{"test0", simpleSmokeBuiltin},
-			 	{"test1", simpleSmokeBuiltin},
-			 	{"test2", simpleSmokeBuiltin}}
+				{"test1", simpleSmokeBuiltin},
+				{"test2", simpleSmokeBuiltin}}
+			},
+			{"contract",
+				{{"balance", std::make_shared<Builtin>(std::bind(&SemanticTest::builtinContractBalance, this, _1))}}
 			}
 		};
 	m_testHooks =
@@ -474,3 +477,16 @@ std::optional<bytes> SemanticTest::builtinSmokeTest(FunctionCall const& call)
 	}
 	return result;
 }
+
+std::optional<bytes> SemanticTest::builtinContractBalance(FunctionCall const& call)
+{
+	assert(call.arguments.parameters.size() <= 1);
+	if (call.arguments.parameters.empty())
+		return util::toBigEndian(SolidityExecutionFramework::balanceAt(m_contractAddress));
+	else
+	{
+		h160 address{util::fromHex(call.arguments.parameters.at(0).rawString)};
+		return util::toBigEndian(SolidityExecutionFramework::balanceAt(address));
+	}
+	return std::nullopt;
+}

test/libsolidity/SemanticTest.h

@@ -66,6 +66,7 @@ class SemanticTest: public SolidityExecutionFramework, public EVMVersionRestrict
 private:
 	// builtin functions
 	std::optional<bytes> builtinSmokeTest(FunctionCall const& call);
+	std::optional<bytes> builtinContractBalance(FunctionCall const& call);
 
 	TestResult runTest(std::ostream& _stream, std::string const& _linePrefix, bool _formatted, bool _compileViaYul, bool _compileToEwasm);
 	SourceMap m_sources;

test/libsolidity/semanticTests/builtins/balance_other_contract.sol

@@ -0,0 +1,23 @@
+contract Other {
+    constructor() payable {
+    }
+    function getAddress() public returns (address) {
+        return address(this);
+    }
+}
+contract ClientReceipt {
+    Other other;
+    constructor() payable {
+        other = new Other{value:500}();
+    }
+    function getAddress() public returns (address) {
+        return other.getAddress();
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// constructor(), 1000 wei ->
+// contract.balance -> 500
+// getAddress() -> 0xF01F7809444BD9A93A854361C6FAE3F23D9E23DB
+// contract.balance(uint256): 0xF01F7809444BD9A93A854361C6FAE3F23D9E23DB -> 500

test/libsolidity/semanticTests/builtins/balance_with_balance.sol

@@ -0,0 +1,8 @@
+contract ClientReceipt {
+    constructor() payable {}
+}
+// ====
+// compileViaYul: also
+// ----
+// constructor(), 1000 wei ->
+// contract.balance -> 1000

test/libsolidity/semanticTests/builtins/balance_without_balance.sol

@@ -0,0 +1,7 @@
+contract ClientReceipt {
+}
+// ====
+// compileViaYul: also
+// ----
+// contract.balance -> 0
+// contract.balance: 0x0000000000000000000000000000000000000000 -> 0