[isoltest] Add support to query balance.

Author: aarlt

test/libsolidity/SemanticTest.cpp

@@ -27,6 +27,7 @@
 #include <algorithm>
 #include <cctype>
 #include <fstream>
+#include <functional>
 #include <memory>
 #include <optional>
 #include <stdexcept>
@@ -131,6 +132,19 @@ void SemanticTest::initializeBuiltins()
 	{
 		return util::toBigEndian(u256(0x1234));
 	};
+	soltestAssert(m_builtins.count("accountBalance") == 0, "");
+	m_builtins["accountBalance"] = [this](FunctionCall const& _call) -> std::optional<bytes>
+	{
+		soltestAssert(_call.arguments.parameters.size() == 1, "Account address expected.");
+		h160 address = h160(_call.arguments.parameters.at(0).rawString);
+		return util::toBigEndian(SolidityExecutionFramework::balanceAt(address));
+	};
+	soltestAssert(m_builtins.count("contractBalance") == 0, "");
+	m_builtins["contractBalance"] = [this](FunctionCall const& _call) -> std::optional<bytes>
+	{
+		soltestAssert(_call.arguments.parameters.empty(), "No arguments expected.");
+		return util::toBigEndian(SolidityExecutionFramework::balanceAt(m_contractAddress));
+	};
 }
 
 TestCase::TestResult SemanticTest::run(ostream& _stream, string const& _linePrefix, bool _formatted)

test/libsolidity/semanticTests/builtins/balance_other_contract.sol

@@ -0,0 +1,29 @@
+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(), 2000 wei ->
+// gas irOptimized: 191881
+// gas legacy: 235167
+// gas legacyOptimized: 180756
+// contractBalance -> 1500
+// gas irOptimized: 191881
+// gas legacy: 235167
+// gas legacyOptimized: 180756
+// getAddress() -> 0xf01f7809444bd9a93a854361c6fae3f23d9e23db
+// accountBalance: 0xf01f7809444bd9a93a854361c6fae3f23d9e23db -> 500

test/libsolidity/semanticTests/builtins/balance_with_balance.sol

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

test/libsolidity/semanticTests/builtins/balance_with_balance2.sol

@@ -0,0 +1,8 @@
+contract ClientReceipt {
+    constructor() payable {}
+}
+// ====
+// compileViaYul: also
+// ----
+// constructor(), 1 ether ->
+// contractBalance -> 1000000000000000000

test/libsolidity/semanticTests/builtins/balance_without_balance.sol

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

test/libsolidity/semanticTests/payable/no_nonpayable_circumvention_by_modifier.sol

@@ -8,14 +8,10 @@ contract C {
     function msgvalue() internal returns (uint) {
         return msg.value;
     }
-    // TODO: remove this helper function once isoltest supports balance checking
-    function balance() external returns (uint) {
-        return address(this).balance;
-    }
 }
 // ====
 // compileViaYul: also
 // compileToEwasm: also
 // ----
 // f(), 27 wei -> FAILURE
-// balance() -> 0
+// contractBalance -> 0