Implement assert as a global function

4 files changed, 16 insertions, 4 deletions

diff --git a/Changelog.md b/Changelog.md
index 0c4e8329..e8656ac8 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,6 +1,7 @@
 ### 0.4.10 (unreleased)
 
 Features:
+ * Add ``assert(condition)`` to abort execution.
  * Type system: Support explicit conversion of external function to address.
 
 Bugfixes:
diff --git a/libsolidity/analysis/GlobalContext.cpp b/libsolidity/analysis/GlobalContext.cpp
index e46868be..cc418c5e 100644
--- a/libsolidity/analysis/GlobalContext.cpp
+++ b/libsolidity/analysis/GlobalContext.cpp
@@ -65,7 +65,9 @@ m_magicVariables(vector<shared_ptr<MagicVariableDeclaration const>>{make_shared<
 					make_shared<MagicVariableDeclaration>("ecrecover",
 							make_shared<FunctionType>(strings{"bytes32", "uint8", "bytes32", "bytes32"}, strings{"address"}, FunctionType::Location::ECRecover)),
 					make_shared<MagicVariableDeclaration>("ripemd160",
-							make_shared<FunctionType>(strings(), strings{"bytes20"}, FunctionType::Location::RIPEMD160, true))})
+							make_shared<FunctionType>(strings(), strings{"bytes20"}, FunctionType::Location::RIPEMD160, true)),
+					make_shared<MagicVariableDeclaration>("assert",
+							make_shared<FunctionType>(strings{"bool"}, strings{}, FunctionType::Location::Assert))})
 {
 }
 
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index e280b32c..83d840e0 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -819,8 +819,8 @@ public:
 	{
 		Internal, ///< stack-call using plain JUMP
 		External, ///< external call using CALL
-		CallCode, ///< extercnal call using CALLCODE, i.e. not exchanging the storage
-		DelegateCall, ///< extercnal call using DELEGATECALL, i.e. not exchanging the storage
+		CallCode, ///< external call using CALLCODE, i.e. not exchanging the storage
+		DelegateCall, ///< external call using DELEGATECALL, i.e. not exchanging the storage
 		Bare, ///< CALL without function hash
 		BareCallCode, ///< CALLCODE without function hash
 		BareDelegateCall, ///< DELEGATECALL without function hash
@@ -844,7 +844,8 @@ public:
 		MulMod, ///< MULMOD
 		ArrayPush, ///< .push() to a dynamically sized array in storage
 		ByteArrayPush, ///< .push() to a dynamically sized byte array in storage
-		ObjectCreation ///< array creation using new
+		ObjectCreation, ///< array creation using new
+		Assert ///< assert()
 	};
 
 	virtual Category category() const override { return Category::Function; }
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index d74d9dd3..a99e3d40 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -863,6 +863,14 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			m_context << Instruction::POP;
 			break;
 		}
+		case Location::Assert:
+		{
+			arguments.front()->accept(*this);
+			utils().convertType(*arguments.front()->annotation().type, *function.parameterTypes().front(), true);
+			m_context << Instruction::ISZERO;
+			m_context.appendConditionalJumpTo(m_context.errorTag());
+			break;
+		}
 		default:
 			BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Invalid function type."));
 		}