Merge pull request #2520 from ethereum/lll-with

LLL: implement the UNSET and WITH keywords

1 files changed, 39 insertions, 0 deletions

diff --git a/liblll/CodeFragment.cpp b/liblll/CodeFragment.cpp
index f37cb8b9..b32f14e9 100644
--- a/liblll/CodeFragment.cpp
+++ b/liblll/CodeFragment.cpp
@@ -259,6 +259,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 		}
 		else if (us == "SET")
 		{
+			// TODO: move this to be a stack variable (and not a memory variable)
 			if (_t.size() != 3)
 				error<IncorrectParameterCount>(us);
 			int c = 0;
@@ -268,6 +269,15 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			m_asm.append((u256)varAddress(firstAsString(), true));
 			m_asm.append(Instruction::MSTORE);
 		}
+		else if (us == "UNSET")
+		{
+			// TODO: this doesn't actually free up anything, since it is a memory variable (see "SET")
+			if (_t.size() != 2)
+				error<IncorrectParameterCount>();
+			auto it = _s.vars.find(firstAsString());
+			if (it != _s.vars.end())
+				_s.vars.erase(it);
+		}
 		else if (us == "GET")
 		{
 			if (_t.size() != 2)
@@ -275,6 +285,35 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			m_asm.append((u256)varAddress(firstAsString()));
 			m_asm.append(Instruction::MLOAD);
 		}
+		else if (us == "WITH")
+		{
+			if (_t.size() != 4)
+				error<IncorrectParameterCount>();
+			string key = firstAsString();
+			if (_s.vars.find(key) != _s.vars.end())
+				error<InvalidName>(string("Symbol already used: ") + key);
+
+			// Create variable
+			// TODO: move this to be a stack variable (and not a memory variable)
+			size_t c = 0;
+			for (auto const& i: _t)
+				if (c++ == 2)
+					m_asm.append(CodeFragment(i, _s, m_readFile, false).m_asm);
+			m_asm.append((u256)varAddress(key, true));
+			m_asm.append(Instruction::MSTORE);
+
+			// Insert sub with variable access, but new state
+			CompilerState ns = _s;
+			c = 0;
+			for (auto const& i: _t)
+				if (c++ == 3)
+					m_asm.append(CodeFragment(i, _s, m_readFile, false).m_asm);
+
+			// Remove variable
+			auto it = _s.vars.find(key);
+			if (it != _s.vars.end())
+				_s.vars.erase(it);
+		}
 		else if (us == "REF")
 			m_asm.append((u256)varAddress(firstAsString()));
 		else if (us == "DEF")