Differential D8836 Diff 26772 src/script/interpreter.cpp

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src/script/interpreter.cpp

Show First 20 Lines • Show All 92 Lines • ▼ Show 20 Lines	switch (opcode) {

default:		default:
break;		break;
}		}

return false;		return false;
}		}

		namespace {
		/**
		* A data type to abstract out the condition stack during script execution.
		*
		* Conceptually it acts like a vector of booleans, one for each level of nested
		* IF/THEN/ELSE, indicating whether we're in the active or inactive branch of
		* each.
		*
		* The elements on the stack cannot be observed individually; we only need to
		* expose whether the stack is empty and whether or not any false values are
		* present at all. To implement OP_ELSE, a toggle_top modifier is added, which
		* flips the last value without returning it.
		*/
		class ConditionStack {
		private:
		std::vector<bool> m_flags;

		public:
		bool empty() { return m_flags.empty(); }
		bool all_true() {
		return !std::count(m_flags.begin(), m_flags.end(), false);
		}
		void push_back(bool f) { m_flags.push_back(f); }
		void pop_back() { m_flags.pop_back(); }
		void toggle_top() { m_flags.back() = !m_flags.back(); }
		};
		} // namespace

bool EvalScript(std::vector<valtype> &stack, const CScript &script,		bool EvalScript(std::vector<valtype> &stack, const CScript &script,
uint32_t flags, const BaseSignatureChecker &checker,		uint32_t flags, const BaseSignatureChecker &checker,
ScriptExecutionMetrics &metrics, ScriptError *serror) {		ScriptExecutionMetrics &metrics, ScriptError *serror) {
static const CScriptNum bnZero(0);		static const CScriptNum bnZero(0);
static const CScriptNum bnOne(1);		static const CScriptNum bnOne(1);
static const valtype vchFalse(0);		static const valtype vchFalse(0);
static const valtype vchTrue(1, 1);		static const valtype vchTrue(1, 1);

CScript::const_iterator pc = script.begin();		CScript::const_iterator pc = script.begin();
CScript::const_iterator pend = script.end();		CScript::const_iterator pend = script.end();
CScript::const_iterator pbegincodehash = script.begin();		CScript::const_iterator pbegincodehash = script.begin();
opcodetype opcode;		opcodetype opcode;
valtype vchPushValue;		valtype vchPushValue;
std::vector<bool> vfExec;		ConditionStack vfExec;
std::vector<valtype> altstack;		std::vector<valtype> altstack;
set_error(serror, ScriptError::UNKNOWN);		set_error(serror, ScriptError::UNKNOWN);
if (script.size() > MAX_SCRIPT_SIZE) {		if (script.size() > MAX_SCRIPT_SIZE) {
return set_error(serror, ScriptError::SCRIPT_SIZE);		return set_error(serror, ScriptError::SCRIPT_SIZE);
}		}
int nOpCount = 0;		int nOpCount = 0;
bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0;		bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0;

try {		try {
while (pc < pend) {		while (pc < pend) {
bool fExec = !count(vfExec.begin(), vfExec.end(), false);		bool fExec = vfExec.all_true();

//		//
// Read instruction		// Read instruction
//		//
if (!script.GetOp(pc, opcode, vchPushValue)) {		if (!script.GetOp(pc, opcode, vchPushValue)) {
return set_error(serror, ScriptError::BAD_OPCODE);		return set_error(serror, ScriptError::BAD_OPCODE);
}		}
if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE) {		if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE) {
▲ Show 20 Lines • Show All 185 Lines • ▼ Show 20 Lines	try {
vfExec.push_back(fValue);		vfExec.push_back(fValue);
} break;		} break;

case OP_ELSE: {		case OP_ELSE: {
if (vfExec.empty()) {		if (vfExec.empty()) {
return set_error(		return set_error(
serror, ScriptError::UNBALANCED_CONDITIONAL);		serror, ScriptError::UNBALANCED_CONDITIONAL);
}		}
vfExec.back() = !vfExec.back();		vfExec.toggle_top();
} break;		} break;

case OP_ENDIF: {		case OP_ENDIF: {
if (vfExec.empty()) {		if (vfExec.empty()) {
return set_error(		return set_error(
serror, ScriptError::UNBALANCED_CONDITIONAL);		serror, ScriptError::UNBALANCED_CONDITIONAL);
}		}
vfExec.pop_back();		vfExec.pop_back();
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