diff --git a/Changelog.md b/Changelog.md
index a53c6a858..9bde3fffd 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -7,6 +7,7 @@ Language Features:
 Compiler Features:
  * Code Generator: Use ``calldatacopy`` instead of ``codecopy`` to zero out memory past input.
  * AST: Add a new node for doxygen-style, structured documentation that can be received by contract, function, event and modifier definitions.
+ * Debug: Provide reason strings for compiler-generated internal reverts when using the ``--revert-strings`` option or the ``settings.debug.revertStrings`` setting on ``debug`` mode.
 
 
 Bugfixes:
diff --git a/docs/using-the-compiler.rst b/docs/using-the-compiler.rst
index fcb611f60..eb4ddf0c6 100644
--- a/docs/using-the-compiler.rst
+++ b/docs/using-the-compiler.rst
@@ -244,7 +244,7 @@ Input Description
           // "default", "strip", "debug" and "verboseDebug".
           // "default" does not inject compiler-generated revert strings and keeps user-supplied ones.
           // "strip" removes all revert strings (if possible, i.e. if literals are used) keeping side-effects
-          // "debug" injects strings for compiler-generated internal reverts (not yet implemented)
+          // "debug" injects strings for compiler-generated internal reverts, implemented for ABI encoders V1 and V2 for now.
           // "verboseDebug" even appends further information to user-supplied revert strings (not yet implemented)
           "revertStrings": "default"
         }
diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp
index df8cacf86..0ad044a54 100644
--- a/libsolidity/codegen/ABIFunctions.cpp
+++ b/libsolidity/codegen/ABIFunctions.cpp
@@ -180,11 +180,12 @@ string ABIFunctions::tupleDecoder(TypePointers const& _types, bool _fromMemory)
 
 		Whiskers templ(R"(
 			function <functionName>(headStart, dataEnd) <arrow> <valueReturnParams> {
-				if slt(sub(dataEnd, headStart), <minimumSize>) { revert(0, 0) }
+				if slt(sub(dataEnd, headStart), <minimumSize>) { <revertString> }
 				<decodeElements>
 			}
 		)");
 		templ("functionName", functionName);
+		templ("revertString", revertReasonIfDebug("ABI decoding: tuple data too short"));
 		templ("minimumSize", to_string(headSize(decodingTypes)));
 
 		string decodeElements;
@@ -211,7 +212,7 @@ string ABIFunctions::tupleDecoder(TypePointers const& _types, bool _fromMemory)
 				R"(
 				{
 					let offset := <load>(add(headStart, <pos>))
-					if gt(offset, 0xffffffffffffffff) { revert(0, 0) }
+					if gt(offset, 0xffffffffffffffff) { <revertString> }
 					<values> := <abiDecode>(add(headStart, offset), dataEnd)
 				}
 				)" :
@@ -222,6 +223,8 @@ string ABIFunctions::tupleDecoder(TypePointers const& _types, bool _fromMemory)
 				}
 				)"
 			);
+			// TODO add test
+			elementTempl("revertString", revertReasonIfDebug("ABI decoding: invalid tuple offset"));
 			elementTempl("load", _fromMemory ? "mload" : "calldataload");
 			elementTempl("values", boost::algorithm::join(valueNamesLocal, ", "));
 			elementTempl("pos", to_string(headPos));
@@ -453,12 +456,14 @@ string ABIFunctions::abiEncodingFunctionCalldataArrayWithoutCleanup(
 			else
 				templ("scaleLengthByStride",
 					Whiskers(R"(
-						if gt(length, <maxLength>) { revert(0, 0) }
+						if gt(length, <maxLength>) { <revertString> }
 						length := mul(length, <stride>)
 					)")
 					("stride", toCompactHexWithPrefix(fromArrayType.calldataStride()))
 					("maxLength", toCompactHexWithPrefix(u256(-1) / fromArrayType.calldataStride()))
+					("revertString", revertReasonIfDebug("ABI encoding: array data too long"))
 					.render()
+					// TODO add revert test
 				);
 			templ("readableTypeNameFrom", _from.toString(true));
 			templ("readableTypeNameTo", _to.toString(true));
@@ -1124,7 +1129,7 @@ string ABIFunctions::abiDecodingFunctionArray(ArrayType const& _type, bool _from
 			R"(
 				// <readableTypeName>
 				function <functionName>(offset, end) -> array {
-					if iszero(slt(add(offset, 0x1f), end)) { revert(0, 0) }
+					if iszero(slt(add(offset, 0x1f), end)) { <revertString> }
 					let length := <retrieveLength>
 					array := <allocate>(<allocationSize>(length))
 					let dst := array
@@ -1141,6 +1146,8 @@ string ABIFunctions::abiDecodingFunctionArray(ArrayType const& _type, bool _from
 				}
 			)"
 		);
+		// TODO add test
+		templ("revertString", revertReasonIfDebug("ABI decoding: invalid calldata array offset"));
 		templ("functionName", functionName);
 		templ("readableTypeName", _type.toString(true));
 		templ("retrieveLength", !_type.isDynamicallySized() ? toCompactHexWithPrefix(_type.length()) : load + "(offset)");
@@ -1159,7 +1166,12 @@ string ABIFunctions::abiDecodingFunctionArray(ArrayType const& _type, bool _from
 		}
 		else
 		{
-			templ("staticBoundsCheck", "if gt(add(src, mul(length, " + calldataStride + ")), end) { revert(0, 0) }");
+			templ("staticBoundsCheck", "if gt(add(src, mul(length, " +
+				calldataStride +
+				")), end) { " +
+				revertReasonIfDebug("ABI decoding: invalid calldata array stride") +
+				" }"
+			);
 			templ("retrieveElementPos", "src");
 		}
 		templ("decodingFun", abiDecodingFunction(*_type.baseType(), _fromMemory, false));
@@ -1184,11 +1196,11 @@ string ABIFunctions::abiDecodingFunctionCalldataArray(ArrayType const& _type)
 			templ = R"(
 				// <readableTypeName>
 				function <functionName>(offset, end) -> arrayPos, length {
-					if iszero(slt(add(offset, 0x1f), end)) { revert(0, 0) }
+					if iszero(slt(add(offset, 0x1f), end)) { <revertStringOffset> }
 					length := calldataload(offset)
-					if gt(length, 0xffffffffffffffff) { revert(0, 0) }
+					if gt(length, 0xffffffffffffffff) { <revertStringLength> }
 					arrayPos := add(offset, 0x20)
-					if gt(add(arrayPos, mul(length, <stride>)), end) { revert(0, 0) }
+					if gt(add(arrayPos, mul(length, <stride>)), end) { <revertStringPos> }
 				}
 			)";
 		else
@@ -1196,10 +1208,14 @@ string ABIFunctions::abiDecodingFunctionCalldataArray(ArrayType const& _type)
 				// <readableTypeName>
 				function <functionName>(offset, end) -> arrayPos {
 					arrayPos := offset
-					if gt(add(arrayPos, mul(<length>, <stride>)), end) { revert(0, 0) }
+					if gt(add(arrayPos, mul(<length>, <stride>)), end) { <revertStringPos> }
 				}
 			)";
 		Whiskers w{templ};
+		// TODO add test
+		w("revertStringOffset", revertReasonIfDebug("ABI decoding: invalid calldata array offset"));
+		w("revertStringLength", revertReasonIfDebug("ABI decoding: invalid calldata array length"));
+		w("revertStringPos", revertReasonIfDebug("ABI decoding: invalid calldata array stride"));
 		w("functionName", functionName);
 		w("readableTypeName", _type.toString(true));
 		w("stride", toCompactHexWithPrefix(_type.calldataStride()));
@@ -1223,17 +1239,20 @@ string ABIFunctions::abiDecodingFunctionByteArray(ArrayType const& _type, bool _
 		Whiskers templ(
 			R"(
 				function <functionName>(offset, end) -> array {
-					if iszero(slt(add(offset, 0x1f), end)) { revert(0, 0) }
+					if iszero(slt(add(offset, 0x1f), end)) { <revertStringOffset> }
 					let length := <load>(offset)
 					array := <allocate>(<allocationSize>(length))
 					mstore(array, length)
 					let src := add(offset, 0x20)
 					let dst := add(array, 0x20)
-					if gt(add(src, length), end) { revert(0, 0) }
+					if gt(add(src, length), end) { <revertStringLength> }
 					<copyToMemFun>(src, dst, length)
 				}
 			)"
 		);
+		// TODO add test
+		templ("revertStringOffset", revertReasonIfDebug("ABI decoding: invalid byte array offset"));
+		templ("revertStringLength", revertReasonIfDebug("ABI decoding: invalid byte array length"));
 		templ("functionName", functionName);
 		templ("load", _fromMemory ? "mload" : "calldataload");
 		templ("allocate", m_utils.allocationFunction());
@@ -1254,10 +1273,12 @@ string ABIFunctions::abiDecodingFunctionCalldataStruct(StructType const& _type)
 		Whiskers w{R"(
 				// <readableTypeName>
 				function <functionName>(offset, end) -> value {
-					if slt(sub(end, offset), <minimumSize>) { revert(0, 0) }
+					if slt(sub(end, offset), <minimumSize>) { <revertString> }
 					value := offset
 				}
 		)"};
+		// TODO add test
+		w("revertString", revertReasonIfDebug("ABI decoding: struct calldata too short"));
 		w("functionName", functionName);
 		w("readableTypeName", _type.toString(true));
 		w("minimumSize", to_string(_type.isDynamicallyEncoded() ? _type.calldataEncodedTailSize() : _type.calldataEncodedSize(true)));
@@ -1277,7 +1298,7 @@ string ABIFunctions::abiDecodingFunctionStruct(StructType const& _type, bool _fr
 		Whiskers templ(R"(
 			// <readableTypeName>
 			function <functionName>(headStart, end) -> value {
-				if slt(sub(end, headStart), <minimumSize>) { revert(0, 0) }
+				if slt(sub(end, headStart), <minimumSize>) { <revertString> }
 				value := <allocate>(<memorySize>)
 				<#members>
 				{
@@ -1287,6 +1308,8 @@ string ABIFunctions::abiDecodingFunctionStruct(StructType const& _type, bool _fr
 				</members>
 			}
 		)");
+		// TODO add test
+		templ("revertString", revertReasonIfDebug("ABI decoding: struct data too short"));
 		templ("functionName", functionName);
 		templ("readableTypeName", _type.toString(true));
 		templ("allocate", m_utils.allocationFunction());
@@ -1305,7 +1328,7 @@ string ABIFunctions::abiDecodingFunctionStruct(StructType const& _type, bool _fr
 				dynamic ?
 				R"(
 					let offset := <load>(add(headStart, <pos>))
-					if gt(offset, 0xffffffffffffffff) { revert(0, 0) }
+					if gt(offset, 0xffffffffffffffff) { <revertString> }
 					mstore(add(value, <memoryOffset>), <abiDecode>(add(headStart, offset), end))
 				)" :
 				R"(
@@ -1313,6 +1336,8 @@ string ABIFunctions::abiDecodingFunctionStruct(StructType const& _type, bool _fr
 					mstore(add(value, <memoryOffset>), <abiDecode>(add(headStart, offset), end))
 				)"
 			);
+			// TODO add test
+			memberTempl("revertString", revertReasonIfDebug("ABI decoding: invalid struct offset"));
 			memberTempl("load", _fromMemory ? "mload" : "calldataload");
 			memberTempl("pos", to_string(headPos));
 			memberTempl("memoryOffset", toCompactHexWithPrefix(_type.memoryOffsetOfMember(member.name)));
@@ -1380,7 +1405,7 @@ string ABIFunctions::calldataAccessFunction(Type const& _type)
 			Whiskers w(R"(
 				function <functionName>(base_ref, ptr) -> <return> {
 					let rel_offset_of_tail := calldataload(ptr)
-					if iszero(slt(rel_offset_of_tail, sub(sub(calldatasize(), base_ref), sub(<neededLength>, 1)))) { revert(0, 0) }
+					if iszero(slt(rel_offset_of_tail, sub(sub(calldatasize(), base_ref), sub(<neededLength>, 1)))) { <revertStringOffset> }
 					value := add(rel_offset_of_tail, base_ref)
 					<handleLength>
 				}
@@ -1392,9 +1417,15 @@ string ABIFunctions::calldataAccessFunction(Type const& _type)
 				w("handleLength", Whiskers(R"(
 					length := calldataload(value)
 					value := add(value, 0x20)
-					if gt(length, 0xffffffffffffffff) { revert(0, 0) }
-					if sgt(base_ref, sub(calldatasize(), mul(length, <calldataStride>))) { revert(0, 0) }
-				)")("calldataStride", toCompactHexWithPrefix(arrayType->calldataStride())).render());
+					if gt(length, 0xffffffffffffffff) { <revertStringLength> }
+					if sgt(base_ref, sub(calldatasize(), mul(length, <calldataStride>))) { <revertStringStride> }
+				)")
+				("calldataStride", toCompactHexWithPrefix(arrayType->calldataStride()))
+				// TODO add test
+				("revertStringLength", revertReasonIfDebug("Invalid calldata access length"))
+				// TODO add test
+				("revertStringStride", revertReasonIfDebug("Invalid calldata access stride"))
+				.render());
 				w("return", "value, length");
 			}
 			else
@@ -1404,6 +1435,7 @@ string ABIFunctions::calldataAccessFunction(Type const& _type)
 			}
 			w("neededLength", toCompactHexWithPrefix(tailSize));
 			w("functionName", functionName);
+			w("revertStringOffset", revertReasonIfDebug("Invalid calldata access offset"));
 			return w.render();
 		}
 		else if (_type.isValueType())
@@ -1493,3 +1525,8 @@ size_t ABIFunctions::numVariablesForType(Type const& _type, EncodingOptions cons
 	else
 		return _type.sizeOnStack();
 }
+
+std::string ABIFunctions::revertReasonIfDebug(std::string const& _message)
+{
+	return YulUtilFunctions::revertReasonIfDebug(m_revertStrings, _message);
+}
diff --git a/libsolidity/codegen/ABIFunctions.h b/libsolidity/codegen/ABIFunctions.h
index f8f09a3f3..a0b8333df 100644
--- a/libsolidity/codegen/ABIFunctions.h
+++ b/libsolidity/codegen/ABIFunctions.h
@@ -25,6 +25,8 @@
 #include <libsolidity/codegen/MultiUseYulFunctionCollector.h>
 #include <libsolidity/codegen/YulUtilFunctions.h>
 
+#include <libsolidity/interface/DebugSettings.h>
+
 #include <liblangutil/EVMVersion.h>
 
 #include <functional>
@@ -55,11 +57,13 @@ class ABIFunctions
 public:
 	explicit ABIFunctions(
 		langutil::EVMVersion _evmVersion,
+		RevertStrings _revertStrings,
 		std::shared_ptr<MultiUseYulFunctionCollector> _functionCollector = std::make_shared<MultiUseYulFunctionCollector>()
 	):
 		m_evmVersion(_evmVersion),
+		m_revertStrings(_revertStrings),
 		m_functionCollector(std::move(_functionCollector)),
-		m_utils(_evmVersion, m_functionCollector)
+		m_utils(_evmVersion, m_revertStrings, m_functionCollector)
 	{}
 
 	/// @returns name of an assembly function to ABI-encode values of @a _givenTypes
@@ -249,7 +253,12 @@ private:
 	/// is true), for which it is two.
 	static size_t numVariablesForType(Type const& _type, EncodingOptions const& _options);
 
+	/// @returns code that stores @param _message for revert reason
+	/// if m_revertStrings is debug.
+	std::string revertReasonIfDebug(std::string const& _message = "");
+
 	langutil::EVMVersion m_evmVersion;
+	RevertStrings const m_revertStrings;
 	std::shared_ptr<MultiUseYulFunctionCollector> m_functionCollector;
 	std::set<std::string> m_externallyUsedFunctions;
 	YulUtilFunctions m_utils;
diff --git a/libsolidity/codegen/Compiler.cpp b/libsolidity/codegen/Compiler.cpp
index a6452adb2..78198fff0 100644
--- a/libsolidity/codegen/Compiler.cpp
+++ b/libsolidity/codegen/Compiler.cpp
@@ -35,7 +35,7 @@ void Compiler::compileContract(
 	bytes const& _metadata
 )
 {
-	ContractCompiler runtimeCompiler(nullptr, m_runtimeContext, m_optimiserSettings, m_revertStrings);
+	ContractCompiler runtimeCompiler(nullptr, m_runtimeContext, m_optimiserSettings);
 	runtimeCompiler.compileContract(_contract, _otherCompilers);
 	m_runtimeContext.appendAuxiliaryData(_metadata);
 
@@ -45,7 +45,7 @@ void Compiler::compileContract(
 	// The creation code will be executed at most once, so we modify the optimizer
 	// settings accordingly.
 	creationSettings.expectedExecutionsPerDeployment = 1;
-	ContractCompiler creationCompiler(&runtimeCompiler, m_context, creationSettings, m_revertStrings);
+	ContractCompiler creationCompiler(&runtimeCompiler, m_context, creationSettings);
 	m_runtimeSub = creationCompiler.compileConstructor(_contract, _otherCompilers);
 
 	m_context.optimise(m_optimiserSettings);
diff --git a/libsolidity/codegen/Compiler.h b/libsolidity/codegen/Compiler.h
index e4a8adc6a..8bd21e586 100644
--- a/libsolidity/codegen/Compiler.h
+++ b/libsolidity/codegen/Compiler.h
@@ -37,9 +37,8 @@ class Compiler
 public:
 	Compiler(langutil::EVMVersion _evmVersion, RevertStrings _revertStrings, OptimiserSettings _optimiserSettings):
 		m_optimiserSettings(std::move(_optimiserSettings)),
-		m_revertStrings(_revertStrings),
-		m_runtimeContext(_evmVersion),
-		m_context(_evmVersion, &m_runtimeContext)
+		m_runtimeContext(_evmVersion, _revertStrings),
+		m_context(_evmVersion, _revertStrings, &m_runtimeContext)
 	{ }
 
 	/// Compiles a contract.
@@ -80,7 +79,6 @@ public:
 
 private:
 	OptimiserSettings const m_optimiserSettings;
-	RevertStrings const m_revertStrings;
 	CompilerContext m_runtimeContext;
 	size_t m_runtimeSub = size_t(-1); ///< Identifier of the runtime sub-assembly, if present.
 	CompilerContext m_context;
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp
index 645e6e61e..f1f386300 100644
--- a/libsolidity/codegen/CompilerContext.cpp
+++ b/libsolidity/codegen/CompilerContext.cpp
@@ -37,6 +37,8 @@
 #include <libyul/Object.h>
 #include <libyul/YulString.h>
 
+#include <libsolutil/Whiskers.h>
+
 #include <liblangutil/ErrorReporter.h>
 #include <liblangutil/Scanner.h>
 #include <liblangutil/SourceReferenceFormatter.h>
@@ -55,6 +57,7 @@
 
 using namespace std;
 using namespace solidity;
+using namespace solidity::util;
 using namespace solidity::evmasm;
 using namespace solidity::frontend;
 using namespace solidity::langutil;
@@ -296,12 +299,13 @@ CompilerContext& CompilerContext::appendConditionalInvalid()
 	return *this;
 }
 
-CompilerContext& CompilerContext::appendRevert()
+CompilerContext& CompilerContext::appendRevert(string const& _message)
 {
-	return *this << u256(0) << u256(0) << Instruction::REVERT;
+	appendInlineAssembly("{ " + revertReasonIfDebug(_message) + " }");
+	return *this;
 }
 
-CompilerContext& CompilerContext::appendConditionalRevert(bool _forwardReturnData)
+CompilerContext& CompilerContext::appendConditionalRevert(bool _forwardReturnData, string const& _message)
 {
 	if (_forwardReturnData && m_evmVersion.supportsReturndata())
 		appendInlineAssembly(R"({
@@ -311,9 +315,7 @@ CompilerContext& CompilerContext::appendConditionalRevert(bool _forwardReturnDat
 			}
 		})", {"condition"});
 	else
-		appendInlineAssembly(R"({
-			if condition { revert(0, 0) }
-		})", {"condition"});
+		appendInlineAssembly("{ if condition { " + revertReasonIfDebug(_message) + " } }", {"condition"});
 	*this << Instruction::POP;
 	return *this;
 }
@@ -488,6 +490,11 @@ vector<ContractDefinition const*>::const_iterator CompilerContext::superContract
 	return ++it;
 }
 
+string CompilerContext::revertReasonIfDebug(string const& _message)
+{
+	return YulUtilFunctions::revertReasonIfDebug(m_revertStrings, _message);
+}
+
 void CompilerContext::updateSourceLocation()
 {
 	m_asm->setSourceLocation(m_visitedNodes.empty() ? SourceLocation() : m_visitedNodes.top()->location());
diff --git a/libsolidity/codegen/CompilerContext.h b/libsolidity/codegen/CompilerContext.h
index 45f16f1f1..28aefa036 100644
--- a/libsolidity/codegen/CompilerContext.h
+++ b/libsolidity/codegen/CompilerContext.h
@@ -27,6 +27,7 @@
 #include <libsolidity/ast/Types.h>
 #include <libsolidity/codegen/ABIFunctions.h>
 
+#include <libsolidity/interface/DebugSettings.h>
 #include <libsolidity/interface/OptimiserSettings.h>
 
 #include <libevmasm/Assembly.h>
@@ -51,11 +52,16 @@ class Compiler;
 class CompilerContext
 {
 public:
-	explicit CompilerContext(langutil::EVMVersion _evmVersion, CompilerContext* _runtimeContext = nullptr):
+	explicit CompilerContext(
+		langutil::EVMVersion _evmVersion,
+		RevertStrings _revertStrings,
+		CompilerContext* _runtimeContext = nullptr
+	):
 		m_asm(std::make_shared<evmasm::Assembly>()),
 		m_evmVersion(_evmVersion),
+		m_revertStrings(_revertStrings),
 		m_runtimeContext(_runtimeContext),
-		m_abiFunctions(m_evmVersion)
+		m_abiFunctions(m_evmVersion, m_revertStrings)
 	{
 		if (m_runtimeContext)
 			m_runtimeSub = size_t(m_asm->newSub(m_runtimeContext->m_asm).data());
@@ -160,12 +166,14 @@ public:
 	/// Appends a conditional INVALID instruction
 	CompilerContext& appendConditionalInvalid();
 	/// Appends a REVERT(0, 0) call
-	CompilerContext& appendRevert();
+	/// @param _message is an optional revert message used in debug mode
+	CompilerContext& appendRevert(std::string const& _message = "");
 	/// Appends a conditional REVERT-call, either forwarding the RETURNDATA or providing the
 	/// empty string. Consumes the condition.
 	/// If the current EVM version does not support RETURNDATA, uses REVERT but does not forward
 	/// the data.
-	CompilerContext& appendConditionalRevert(bool _forwardReturnData = false);
+	/// @param _message is an optional revert message used in debug mode
+	CompilerContext& appendConditionalRevert(bool _forwardReturnData = false, std::string const& _message = "");
 	/// Appends a JUMP to a specific tag
 	CompilerContext& appendJumpTo(
 		evmasm::AssemblyItem const& _tag,
@@ -219,6 +227,11 @@ public:
 		OptimiserSettings const& _optimiserSettings = OptimiserSettings::none()
 	);
 
+	/// If m_revertStrings is debug, @returns inline assembly code that
+	/// stores @param _message in memory position 0 and reverts.
+	/// Otherwise returns "revert(0, 0)".
+	std::string revertReasonIfDebug(std::string const& _message = "");
+
 	/// Appends arbitrary data to the end of the bytecode.
 	void appendAuxiliaryData(bytes const& _data) { m_asm->appendAuxiliaryDataToEnd(_data); }
 
@@ -263,6 +276,8 @@ public:
 
 	void setModifierDepth(size_t _modifierDepth) { m_asm->m_currentModifierDepth = _modifierDepth; }
 
+	RevertStrings revertStrings() const { return m_revertStrings; }
+
 private:
 	/// Searches the inheritance hierarchy towards the base starting from @a _searchStart and returns
 	/// the first function definition that is overwritten by _function.
@@ -312,6 +327,7 @@ private:
 	evmasm::AssemblyPointer m_asm;
 	/// Version of the EVM to compile against.
 	langutil::EVMVersion m_evmVersion;
+	RevertStrings const m_revertStrings;
 	/// Activated experimental features.
 	std::set<ExperimentalFeature> m_experimentalFeatures;
 	/// Other already compiled contracts to be used in contract creation calls.
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index c15d2537e..4c75081ff 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -130,9 +130,12 @@ void CompilerUtils::accessCalldataTail(Type const& _type)
 	// returns the absolute offset of the tail in "base_ref"
 	m_context.appendInlineAssembly(Whiskers(R"({
 		let rel_offset_of_tail := calldataload(ptr_to_tail)
-		if iszero(slt(rel_offset_of_tail, sub(sub(calldatasize(), base_ref), sub(<neededLength>, 1)))) { revert(0, 0) }
+		if iszero(slt(rel_offset_of_tail, sub(sub(calldatasize(), base_ref), sub(<neededLength>, 1)))) { <revertString> }
 		base_ref := add(base_ref, rel_offset_of_tail)
-	})")("neededLength", toCompactHexWithPrefix(tailSize)).render(), {"base_ref", "ptr_to_tail"});
+	})")
+	("neededLength", toCompactHexWithPrefix(tailSize))
+	("revertString", m_context.revertReasonIfDebug("Invalid calldata tail offset"))
+	.render(), {"base_ref", "ptr_to_tail"});
 	// stack layout: <absolute_offset_of_tail> <garbage>
 
 	if (!_type.isDynamicallySized())
@@ -158,9 +161,12 @@ void CompilerUtils::accessCalldataTail(Type const& _type)
 			Whiskers(R"({
 				length := calldataload(base_ref)
 				base_ref := add(base_ref, 0x20)
-				if gt(length, 0xffffffffffffffff) { revert(0, 0) }
+				if gt(length, 0xffffffffffffffff) { <revertString> }
 				if sgt(base_ref, sub(calldatasize(), mul(length, <calldataStride>))) { revert(0, 0) }
-			})")("calldataStride", toCompactHexWithPrefix(calldataStride)).render(),
+			})")
+			("calldataStride", toCompactHexWithPrefix(calldataStride))
+			("revertString", m_context.revertReasonIfDebug("Invalid calldata tail length"))
+			.render(),
 			{"base_ref", "length"}
 		);
 		// stack layout: <absolute_offset_of_tail> <length>
@@ -277,7 +283,13 @@ void CompilerUtils::abiDecode(TypePointers const& _typeParameters, bool _fromMem
 	size_t encodedSize = 0;
 	for (auto const& t: _typeParameters)
 		encodedSize += t->decodingType()->calldataHeadSize();
-	m_context.appendInlineAssembly("{ if lt(len, " + to_string(encodedSize) + ") { revert(0, 0) } }", {"len"});
+
+	Whiskers templ(R"({
+		if lt(len, <encodedSize>) { <revertString> }
+	})");
+	templ("encodedSize", to_string(encodedSize));
+	templ("revertString", m_context.revertReasonIfDebug("Calldata too short"));
+	m_context.appendInlineAssembly(templ.render(), {"len"});
 
 	m_context << Instruction::DUP2 << Instruction::ADD;
 	m_context << Instruction::SWAP1;
@@ -319,19 +331,23 @@ void CompilerUtils::abiDecode(TypePointers const& _typeParameters, bool _fromMem
 					// Check that the data pointer is valid and that length times
 					// item size is still inside the range.
 					Whiskers templ(R"({
-						if gt(ptr, 0x100000000) { revert(0, 0) }
+						if gt(ptr, 0x100000000) { <revertStringPointer> }
 						ptr := add(ptr, base_offset)
 						let array_data_start := add(ptr, 0x20)
-						if gt(array_data_start, input_end) { revert(0, 0) }
+						if gt(array_data_start, input_end) { <revertStringStart> }
 						let array_length := mload(ptr)
 						if or(
 							gt(array_length, 0x100000000),
 							gt(add(array_data_start, mul(array_length, <item_size>)), input_end)
-						) { revert(0, 0) }
+						) { <revertStringLength> }
 						mstore(dst, array_length)
 						dst := add(dst, 0x20)
 					})");
 					templ("item_size", to_string(arrayType.calldataStride()));
+					// TODO add test
+					templ("revertStringPointer", m_context.revertReasonIfDebug("ABI memory decoding: invalid data pointer"));
+					templ("revertStringStart", m_context.revertReasonIfDebug("ABI memory decoding: invalid data start"));
+					templ("revertStringLength", m_context.revertReasonIfDebug("ABI memory decoding: invalid data length"));
 					m_context.appendInlineAssembly(templ.render(), {"input_end", "base_offset", "offset", "ptr", "dst"});
 					// stack: v1 v2 ... v(k-1) dstmem input_end base_offset current_offset data_ptr dstdata
 					m_context << Instruction::SWAP1;
@@ -359,24 +375,33 @@ void CompilerUtils::abiDecode(TypePointers const& _typeParameters, bool _fromMem
 					loadFromMemoryDynamic(*TypeProvider::uint256(), !_fromMemory);
 					m_context << Instruction::SWAP1;
 					// stack: input_end base_offset next_pointer data_offset
-					m_context.appendInlineAssembly("{ if gt(data_offset, 0x100000000) { revert(0, 0) } }", {"data_offset"});
+					m_context.appendInlineAssembly(Whiskers(R"({
+						if gt(data_offset, 0x100000000) { <revertString> }
+					})")
+					// TODO add test
+					("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid data offset"))
+					.render(), {"data_offset"});
 					m_context << Instruction::DUP3 << Instruction::ADD;
 					// stack: input_end base_offset next_pointer array_head_ptr
-					m_context.appendInlineAssembly(
-						"{ if gt(add(array_head_ptr, 0x20), input_end) { revert(0, 0) } }",
-						{"input_end", "base_offset", "next_ptr", "array_head_ptr"}
-					);
+					m_context.appendInlineAssembly(Whiskers(R"({
+						if gt(add(array_head_ptr, 0x20), input_end) { <revertString> }
+					})")
+					("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid head pointer"))
+					.render(), {"input_end", "base_offset", "next_ptr", "array_head_ptr"});
+
 					// retrieve length
 					loadFromMemoryDynamic(*TypeProvider::uint256(), !_fromMemory, true);
 					// stack: input_end base_offset next_pointer array_length data_pointer
 					m_context << Instruction::SWAP2;
 					// stack: input_end base_offset data_pointer array_length next_pointer
-					m_context.appendInlineAssembly(R"({
+					m_context.appendInlineAssembly(Whiskers(R"({
 						if or(
 							gt(array_length, 0x100000000),
 							gt(add(data_ptr, mul(array_length, )" + to_string(arrayType.calldataStride()) + R"()), input_end)
-						) { revert(0, 0) }
-					})", {"input_end", "base_offset", "data_ptr", "array_length", "next_ptr"});
+						) { <revertString> }
+					})")
+					("revertString", m_context.revertReasonIfDebug("ABI calldata decoding: invalid data pointer"))
+					.render(), {"input_end", "base_offset", "data_ptr", "array_length", "next_ptr"});
 				}
 				else
 				{
@@ -792,8 +817,7 @@ void CompilerUtils::convertType(
 			solAssert(enumType.numberOfMembers() > 0, "empty enum should have caused a parser error.");
 			m_context << u256(enumType.numberOfMembers() - 1) << Instruction::DUP2 << Instruction::GT;
 			if (_asPartOfArgumentDecoding)
-				// TODO: error message?
-				m_context.appendConditionalRevert();
+				m_context.appendConditionalRevert(false, "Enum out of range");
 			else
 				m_context.appendConditionalInvalid();
 			enumOverflowCheckPending = false;
diff --git a/libsolidity/codegen/CompilerUtils.h b/libsolidity/codegen/CompilerUtils.h
index 5cc0ac9c8..3d5d85825 100644
--- a/libsolidity/codegen/CompilerUtils.h
+++ b/libsolidity/codegen/CompilerUtils.h
@@ -24,6 +24,7 @@
 
 #include <libsolidity/ast/ASTForward.h>
 #include <libsolidity/ast/TypeProvider.h>
+#include <libsolidity/interface/DebugSettings.h>
 #include <libsolidity/codegen/CompilerContext.h>
 #include <libsolidity/codegen/CompilerContext.h>
 
@@ -34,7 +35,8 @@ class Type; // forward
 class CompilerUtils
 {
 public:
-	explicit CompilerUtils(CompilerContext& _context): m_context(_context) {}
+	explicit CompilerUtils(CompilerContext& _context): m_context(_context)
+	{}
 
 	/// Stores the initial value of the free-memory-pointer at its position;
 	void initialiseFreeMemoryPointer();
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index ecf62d29a..bbf6472de 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -128,8 +128,7 @@ void ContractCompiler::appendCallValueCheck()
 {
 	// Throw if function is not payable but call contained ether.
 	m_context << Instruction::CALLVALUE;
-	// TODO: error message?
-	m_context.appendConditionalRevert();
+	m_context.appendConditionalRevert(false, "Ether sent to non-payable function");
 }
 
 void ContractCompiler::appendInitAndConstructorCode(ContractDefinition const& _contract)
@@ -409,7 +408,7 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
 	m_context << notFoundOrReceiveEther;
 
 	if (!fallback && !etherReceiver)
-		m_context.appendRevert();
+		m_context.appendRevert("Contract does not have fallback nor receive functions");
 	else
 	{
 		if (etherReceiver)
@@ -440,8 +439,7 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
 			m_context << Instruction::STOP;
 		}
 		else
-			// TODO: error message here?
-			m_context.appendRevert();
+			m_context.appendRevert("Unknown signature and no fallback defined");
 	}
 
 
@@ -457,7 +455,7 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
 			// If the function is not a view function and is called without DELEGATECALL,
 			// we revert.
 			m_context << dupInstruction(2);
-			m_context.appendConditionalRevert();
+			m_context.appendConditionalRevert(false, "Non-view function of library called without DELEGATECALL");
 		}
 		m_context.setStackOffset(0);
 		// We have to allow this for libraries, because value of the previous
@@ -517,7 +515,7 @@ void ContractCompiler::initializeStateVariables(ContractDefinition const& _contr
 	solAssert(!_contract.isLibrary(), "Tried to initialize state variables of library.");
 	for (VariableDeclaration const* variable: _contract.stateVariables())
 		if (variable->value() && !variable->isConstant())
-			ExpressionCompiler(m_context, m_revertStrings, m_optimiserSettings.runOrderLiterals).appendStateVariableInitialization(*variable);
+			ExpressionCompiler(m_context, m_optimiserSettings.runOrderLiterals).appendStateVariableInitialization(*variable);
 }
 
 bool ContractCompiler::visit(VariableDeclaration const& _variableDeclaration)
@@ -530,10 +528,10 @@ bool ContractCompiler::visit(VariableDeclaration const& _variableDeclaration)
 	m_continueTags.clear();
 
 	if (_variableDeclaration.isConstant())
-		ExpressionCompiler(m_context, m_revertStrings, m_optimiserSettings.runOrderLiterals)
+		ExpressionCompiler(m_context, m_optimiserSettings.runOrderLiterals)
 			.appendConstStateVariableAccessor(_variableDeclaration);
 	else
-		ExpressionCompiler(m_context, m_revertStrings, m_optimiserSettings.runOrderLiterals)
+		ExpressionCompiler(m_context, m_optimiserSettings.runOrderLiterals)
 			.appendStateVariableAccessor(_variableDeclaration);
 
 	return false;
@@ -954,7 +952,8 @@ void ContractCompiler::handleCatch(vector<ASTPointer<TryCatchClause>> const& _ca
 				revert(0, returndatasize())
 			})");
 		else
-			m_context.appendRevert();
+			// Since both returndata and revert are >=byzantium, this should be unreachable.
+			solAssert(false, "");
 	}
 	m_context << endTag;
 }
@@ -1316,7 +1315,7 @@ void ContractCompiler::appendStackVariableInitialisation(VariableDeclaration con
 
 void ContractCompiler::compileExpression(Expression const& _expression, TypePointer const& _targetType)
 {
-	ExpressionCompiler expressionCompiler(m_context, m_revertStrings, m_optimiserSettings.runOrderLiterals);
+	ExpressionCompiler expressionCompiler(m_context, m_optimiserSettings.runOrderLiterals);
 	expressionCompiler.compile(_expression);
 	if (_targetType)
 		CompilerUtils(m_context).convertType(*_expression.annotation().type, *_targetType);
diff --git a/libsolidity/codegen/ContractCompiler.h b/libsolidity/codegen/ContractCompiler.h
index 02fcbe4ca..0a2ecf7e8 100644
--- a/libsolidity/codegen/ContractCompiler.h
+++ b/libsolidity/codegen/ContractCompiler.h
@@ -43,11 +43,9 @@ public:
 	explicit ContractCompiler(
 		ContractCompiler* _runtimeCompiler,
 		CompilerContext& _context,
-		OptimiserSettings _optimiserSettings,
-		RevertStrings _revertStrings
+		OptimiserSettings _optimiserSettings
 	):
 		m_optimiserSettings(std::move(_optimiserSettings)),
-		m_revertStrings(_revertStrings),
 		m_runtimeCompiler(_runtimeCompiler),
 		m_context(_context)
 	{
@@ -140,7 +138,6 @@ private:
 	void storeStackHeight(ASTNode const* _node);
 
 	OptimiserSettings const m_optimiserSettings;
-	RevertStrings const m_revertStrings;
 	/// Pointer to the runtime compiler in case this is a creation compiler.
 	ContractCompiler* m_runtimeCompiler = nullptr;
 	CompilerContext& m_context;
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index a2812ce51..c8ded9078 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -677,7 +677,6 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 				m_context << errorCase;
 			}
 			else
-				// TODO: Can we bubble up here? There might be different reasons for failure, I think.
 				m_context.appendConditionalRevert(true);
 			break;
 		}
@@ -734,8 +733,8 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			if (function.kind() == FunctionType::Kind::Transfer)
 			{
 				// Check if zero (out of stack or not enough balance).
-				// TODO: bubble up here, but might also be different error.
 				m_context << Instruction::ISZERO;
+				// Revert message bubbles up.
 				m_context.appendConditionalRevert(true);
 			}
 			break;
@@ -752,7 +751,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 				// function-sel(Error(string)) + encoding
 				solAssert(arguments.size() == 1, "");
 				solAssert(function.parameterTypes().size() == 1, "");
-				if (m_revertStrings == RevertStrings::Strip)
+				if (m_context.revertStrings() == RevertStrings::Strip)
 				{
 					if (!arguments.front()->annotation().isPure)
 					{
@@ -1032,7 +1031,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 		{
 			acceptAndConvert(*arguments.front(), *function.parameterTypes().front(), false);
 
-			bool haveReasonString = arguments.size() > 1 && m_revertStrings != RevertStrings::Strip;
+			bool haveReasonString = arguments.size() > 1 && m_context.revertStrings() != RevertStrings::Strip;
 
 			if (arguments.size() > 1)
 			{
@@ -1041,7 +1040,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 				// function call.
 				solAssert(arguments.size() == 2, "");
 				solAssert(function.kind() == FunctionType::Kind::Require, "");
-				if (m_revertStrings == RevertStrings::Strip)
+				if (m_context.revertStrings() == RevertStrings::Strip)
 				{
 					if (!arguments.at(1)->annotation().isPure)
 					{
@@ -1821,12 +1820,16 @@ bool ExpressionCompiler::visit(IndexRangeAccess const& _indexAccess)
 
 	m_context.appendInlineAssembly(
 		Whiskers(R"({
-					if gt(sliceStart, sliceEnd) { revert(0, 0) }
-					if gt(sliceEnd, length) { revert(0, 0) }
+					if gt(sliceStart, sliceEnd) { <revertStringStartEnd> }
+					if gt(sliceEnd, length) { <revertStringEndLength> }
 
 					offset := add(offset, mul(sliceStart, <stride>))
 					length := sub(sliceEnd, sliceStart)
-				})")("stride", toString(arrayType->calldataStride())).render(),
+				})")
+		("stride", toString(arrayType->calldataStride()))
+		("revertStringStartEnd", m_context.revertReasonIfDebug("Slice starts after end"))
+		("revertStringEndLength", m_context.revertReasonIfDebug("Slice is greater than length"))
+		.render(),
 		{"offset", "length", "sliceStart", "sliceEnd"}
 	);
 
@@ -2299,8 +2302,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	if (funKind == FunctionType::Kind::External || funKind == FunctionType::Kind::DelegateCall)
 	{
 		m_context << Instruction::DUP1 << Instruction::EXTCODESIZE << Instruction::ISZERO;
-		// TODO: error message?
-		m_context.appendConditionalRevert();
+		m_context.appendConditionalRevert(false, "Target contract does not contain code");
 		existenceChecked = true;
 	}
 
diff --git a/libsolidity/codegen/ExpressionCompiler.h b/libsolidity/codegen/ExpressionCompiler.h
index a64efd657..33fb2696f 100644
--- a/libsolidity/codegen/ExpressionCompiler.h
+++ b/libsolidity/codegen/ExpressionCompiler.h
@@ -58,10 +58,8 @@ class ExpressionCompiler: private ASTConstVisitor
 public:
 	ExpressionCompiler(
 		CompilerContext& _compilerContext,
-		RevertStrings _revertStrings,
 		bool _optimiseOrderLiterals
 	):
-		m_revertStrings(_revertStrings),
 		m_optimiseOrderLiterals(_optimiseOrderLiterals),
 		m_context(_compilerContext)
 	{}
@@ -139,7 +137,6 @@ private:
 	/// @returns the CompilerUtils object containing the current context.
 	CompilerUtils utils();
 
-	RevertStrings m_revertStrings;
 	bool m_optimiseOrderLiterals;
 	CompilerContext& m_context;
 	std::unique_ptr<LValue> m_currentLValue;
diff --git a/libsolidity/codegen/YulUtilFunctions.cpp b/libsolidity/codegen/YulUtilFunctions.cpp
index b06d07182..4cc2c8714 100644
--- a/libsolidity/codegen/YulUtilFunctions.cpp
+++ b/libsolidity/codegen/YulUtilFunctions.cpp
@@ -134,7 +134,7 @@ string YulUtilFunctions::requireOrAssertFunction(bool _assert, Type const* _mess
 				FixedHash<hashHeaderSize>(keccak256("Error(string)"))
 			)) << (256 - hashHeaderSize * byteSize);
 
-		string const encodeFunc = ABIFunctions(m_evmVersion, m_functionCollector)
+		string const encodeFunc = ABIFunctions(m_evmVersion, m_revertStrings, m_functionCollector)
 			.tupleEncoder(
 				{_messageType},
 				{TypeProvider::stringMemory()}
@@ -1627,7 +1627,7 @@ string YulUtilFunctions::packedHashFunction(
 		templ("variables", suffixedVariableNameList("var_", 1, 1 + sizeOnStack));
 		templ("comma", sizeOnStack > 0 ? "," : "");
 		templ("freeMemoryPointer", to_string(CompilerUtils::freeMemoryPointer));
-		templ("packedEncode", ABIFunctions(m_evmVersion, m_functionCollector).tupleEncoderPacked(_givenTypes, _targetTypes));
+		templ("packedEncode", ABIFunctions(m_evmVersion, m_revertStrings, m_functionCollector).tupleEncoderPacked(_givenTypes, _targetTypes));
 		return templ.render();
 	});
 }
@@ -1905,3 +1905,41 @@ string YulUtilFunctions::readFromMemoryOrCalldata(Type const& _type, bool _fromC
 		.render();
 	});
 }
+
+string YulUtilFunctions::revertReasonIfDebug(RevertStrings revertStrings, string const& _message)
+{
+	if (revertStrings >= RevertStrings::Debug && !_message.empty())
+	{
+		Whiskers templ(R"({
+			mstore(0, <sig>)
+			mstore(4, 0x20)
+			mstore(add(4, 0x20), <length>)
+			let reasonPos := add(4, 0x40)
+			<#word>
+				mstore(add(reasonPos, <offset>), <wordValue>)
+			</word>
+			revert(0, add(reasonPos, <end>))
+		})");
+		templ("sig", (u256(util::FixedHash<4>::Arith(util::FixedHash<4>(util::keccak256("Error(string)")))) << (256 - 32)).str());
+		templ("length", to_string(_message.length()));
+
+		size_t words = (_message.length() + 31) / 32;
+		vector<map<string, string>> wordParams(words);
+		for (size_t i = 0; i < words; ++i)
+		{
+			wordParams[i]["offset"] = to_string(i * 32);
+			wordParams[i]["wordValue"] = formatAsStringOrNumber(_message.substr(32 * i, 32));
+		}
+		templ("word", wordParams);
+		templ("end", to_string(words * 32));
+
+		return templ.render();
+	}
+	else
+		return "revert(0, 0)";
+}
+
+string YulUtilFunctions::revertReasonIfDebug(string const& _message)
+{
+	return revertReasonIfDebug(m_revertStrings, _message);
+}
diff --git a/libsolidity/codegen/YulUtilFunctions.h b/libsolidity/codegen/YulUtilFunctions.h
index df6292b42..859290ffa 100644
--- a/libsolidity/codegen/YulUtilFunctions.h
+++ b/libsolidity/codegen/YulUtilFunctions.h
@@ -24,6 +24,8 @@
 
 #include <libsolidity/codegen/MultiUseYulFunctionCollector.h>
 
+#include <libsolidity/interface/DebugSettings.h>
+
 #include <memory>
 #include <string>
 #include <vector>
@@ -44,9 +46,11 @@ class YulUtilFunctions
 public:
 	explicit YulUtilFunctions(
 		langutil::EVMVersion _evmVersion,
+		RevertStrings _revertStrings,
 		std::shared_ptr<MultiUseYulFunctionCollector> _functionCollector
 	):
 		m_evmVersion(_evmVersion),
+		m_revertStrings(_revertStrings),
 		m_functionCollector(std::move(_functionCollector))
 	{}
 
@@ -281,6 +285,13 @@ public:
 	/// zero
 	/// signature: (slot, offset) ->
 	std::string storageSetToZeroFunction(Type const& _type);
+
+	/// If revertStrings is debug, @returns inline assembly code that
+	/// stores @param _message in memory position 0 and reverts.
+	/// Otherwise returns "revert(0, 0)".
+	static std::string revertReasonIfDebug(RevertStrings revertStrings, std::string const& _message = "");
+
+	std::string revertReasonIfDebug(std::string const& _message = "");
 private:
 	/// Special case of conversionFunction - handles everything that does not
 	/// use exactly one variable to hold the value.
@@ -289,6 +300,7 @@ private:
 	std::string readFromMemoryOrCalldata(Type const& _type, bool _fromCalldata);
 
 	langutil::EVMVersion m_evmVersion;
+	RevertStrings m_revertStrings;
 	std::shared_ptr<MultiUseYulFunctionCollector> m_functionCollector;
 };
 
diff --git a/libsolidity/codegen/ir/IRGenerationContext.cpp b/libsolidity/codegen/ir/IRGenerationContext.cpp
index 9c8e3b974..bd54e1fbd 100644
--- a/libsolidity/codegen/ir/IRGenerationContext.cpp
+++ b/libsolidity/codegen/ir/IRGenerationContext.cpp
@@ -133,7 +133,7 @@ string IRGenerationContext::internalDispatch(size_t _in, size_t _out)
 		)");
 		templ("functionName", funName);
 		templ("comma", _in > 0 ? "," : "");
-		YulUtilFunctions utils(m_evmVersion, m_functions);
+		YulUtilFunctions utils(m_evmVersion, m_revertStrings, m_functions);
 		templ("in", suffixedVariableNameList("in_", 0, _in));
 		templ("arrow", _out > 0 ? "->" : "");
 		templ("out", suffixedVariableNameList("out_", 0, _out));
@@ -161,5 +161,10 @@ string IRGenerationContext::internalDispatch(size_t _in, size_t _out)
 
 YulUtilFunctions IRGenerationContext::utils()
 {
-	return YulUtilFunctions(m_evmVersion, m_functions);
+	return YulUtilFunctions(m_evmVersion, m_revertStrings, m_functions);
+}
+
+std::string IRGenerationContext::revertReasonIfDebug(std::string const& _message)
+{
+	return YulUtilFunctions::revertReasonIfDebug(m_revertStrings, _message);
 }
diff --git a/libsolidity/codegen/ir/IRGenerationContext.h b/libsolidity/codegen/ir/IRGenerationContext.h
index 9c1844f08..698a6d38a 100644
--- a/libsolidity/codegen/ir/IRGenerationContext.h
+++ b/libsolidity/codegen/ir/IRGenerationContext.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <libsolidity/interface/OptimiserSettings.h>
+#include <libsolidity/interface/DebugSettings.h>
 
 #include <libsolidity/codegen/MultiUseYulFunctionCollector.h>
 
@@ -47,8 +48,13 @@ class YulUtilFunctions;
 class IRGenerationContext
 {
 public:
-	IRGenerationContext(langutil::EVMVersion _evmVersion, OptimiserSettings _optimiserSettings):
+	IRGenerationContext(
+		langutil::EVMVersion _evmVersion,
+		RevertStrings _revertStrings,
+		OptimiserSettings _optimiserSettings
+	):
 		m_evmVersion(_evmVersion),
+		m_revertStrings(_revertStrings),
 		m_optimiserSettings(std::move(_optimiserSettings)),
 		m_functions(std::make_shared<MultiUseYulFunctionCollector>())
 	{}
@@ -92,8 +98,15 @@ public:
 
 	langutil::EVMVersion evmVersion() const { return m_evmVersion; };
 
+	/// @returns code that stores @param _message for revert reason
+	/// if m_revertStrings is debug.
+	std::string revertReasonIfDebug(std::string const& _message = "");
+
+	RevertStrings revertStrings() const { return m_revertStrings; }
+
 private:
 	langutil::EVMVersion m_evmVersion;
+	RevertStrings m_revertStrings;
 	OptimiserSettings m_optimiserSettings;
 	std::vector<ContractDefinition const*> m_inheritanceHierarchy;
 	std::map<VariableDeclaration const*, std::string> m_localVariables;
diff --git a/libsolidity/codegen/ir/IRGenerator.cpp b/libsolidity/codegen/ir/IRGenerator.cpp
index 0798ebc37..69c47df00 100644
--- a/libsolidity/codegen/ir/IRGenerator.cpp
+++ b/libsolidity/codegen/ir/IRGenerator.cpp
@@ -333,7 +333,7 @@ string IRGenerator::dispatchRoutine(ContractDefinition const& _contract)
 		templ["assignToParams"] = paramVars == 0 ? "" : "let " + suffixedVariableNameList("param_", 0, paramVars) + " := ";
 		templ["assignToRetParams"] = retVars == 0 ? "" : "let " + suffixedVariableNameList("ret_", 0, retVars) + " := ";
 
-		ABIFunctions abiFunctions(m_evmVersion, m_context.functionCollector());
+		ABIFunctions abiFunctions(m_evmVersion, m_context.revertStrings(), m_context.functionCollector());
 		templ["abiDecode"] = abiFunctions.tupleDecoder(type->parameterTypes());
 		templ["params"] = suffixedVariableNameList("param_", 0, paramVars);
 		templ["retParams"] = suffixedVariableNameList("ret_", retVars, 0);
@@ -386,8 +386,8 @@ void IRGenerator::resetContext(ContractDefinition const& _contract)
 		m_context.functionCollector()->requestedFunctions().empty(),
 		"Reset context while it still had functions."
 	);
-	m_context = IRGenerationContext(m_evmVersion, m_optimiserSettings);
-	m_utils = YulUtilFunctions(m_evmVersion, m_context.functionCollector());
+	m_context = IRGenerationContext(m_evmVersion, m_context.revertStrings(), m_optimiserSettings);
+	m_utils = YulUtilFunctions(m_evmVersion, m_context.revertStrings(), m_context.functionCollector());
 
 	m_context.setInheritanceHierarchy(_contract.annotation().linearizedBaseContracts);
 	for (auto const& var: ContractType(_contract).stateVariables())
diff --git a/libsolidity/codegen/ir/IRGenerator.h b/libsolidity/codegen/ir/IRGenerator.h
index 2481f08dd..d1ec580f6 100644
--- a/libsolidity/codegen/ir/IRGenerator.h
+++ b/libsolidity/codegen/ir/IRGenerator.h
@@ -37,11 +37,15 @@ class SourceUnit;
 class IRGenerator
 {
 public:
-	IRGenerator(langutil::EVMVersion _evmVersion, OptimiserSettings _optimiserSettings):
+	IRGenerator(
+		langutil::EVMVersion _evmVersion,
+		RevertStrings _revertStrings,
+		OptimiserSettings _optimiserSettings
+	):
 		m_evmVersion(_evmVersion),
 		m_optimiserSettings(_optimiserSettings),
-		m_context(_evmVersion, std::move(_optimiserSettings)),
-		m_utils(_evmVersion, m_context.functionCollector())
+		m_context(_evmVersion, _revertStrings, std::move(_optimiserSettings)),
+		m_utils(_evmVersion, m_context.revertStrings(), m_context.functionCollector())
 	{}
 
 	/// Generates and returns the IR code, in unoptimized and optimized form
diff --git a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
index 16c11e3e7..2d38fe026 100644
--- a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
+++ b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
@@ -534,7 +534,7 @@ void IRGeneratorForStatements::endVisit(FunctionCall const& _functionCall)
 	{
 		auto const& event = dynamic_cast<EventDefinition const&>(functionType->declaration());
 		TypePointers paramTypes = functionType->parameterTypes();
-		ABIFunctions abi(m_context.evmVersion(), m_context.functionCollector());
+		ABIFunctions abi(m_context.evmVersion(), m_context.revertStrings(), m_context.functionCollector());
 
 		vector<string> indexedArgs;
 		string nonIndexedArgs;
@@ -1151,7 +1151,7 @@ void IRGeneratorForStatements::appendExternalFunctionCall(
 			m_code << "mstore(add(" << fetchFreeMem() << ", " << to_string(retSize) << "), 0)\n";
 	}
 
-	ABIFunctions abi(m_context.evmVersion(), m_context.functionCollector());
+	ABIFunctions abi(m_context.evmVersion(), m_context.revertStrings(), m_context.functionCollector());
 
 	solUnimplementedAssert(!funType.isBareCall(), "");
 	Whiskers templ(R"(
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index dfa7629da..6940730cf 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -165,7 +165,7 @@ void CompilerStack::setRevertStringBehaviour(RevertStrings _revertStrings)
 {
 	if (m_stackState >= ParsingPerformed)
 		BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Must set revert string settings before parsing."));
-	solUnimplementedAssert(_revertStrings == RevertStrings::Default || _revertStrings == RevertStrings::Strip, "");
+	solUnimplementedAssert(_revertStrings != RevertStrings::VerboseDebug, "");
 	m_revertStrings = _revertStrings;
 }
 
@@ -1112,7 +1112,7 @@ void CompilerStack::generateIR(ContractDefinition const& _contract)
 	for (auto const* dependency: _contract.annotation().contractDependencies)
 		generateIR(*dependency);
 
-	IRGenerator generator(m_evmVersion, m_optimiserSettings);
+	IRGenerator generator(m_evmVersion, m_revertStrings, m_optimiserSettings);
 	tie(compiledContract.yulIR, compiledContract.yulIROptimized) = generator.run(_contract);
 }
 
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 3a86914d1..1b09b2f2c 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -661,10 +661,10 @@ boost::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompile
 			std::optional<RevertStrings> revertStrings = revertStringsFromString(settings["debug"]["revertStrings"].asString());
 			if (!revertStrings)
 				return formatFatalError("JSONError", "Invalid value for settings.debug.revertStrings.");
-			if (*revertStrings != RevertStrings::Default && *revertStrings != RevertStrings::Strip)
+			if (*revertStrings == RevertStrings::VerboseDebug)
 				return formatFatalError(
 					"UnimplementedFeatureError",
-					"Only \"default\" and \"strip\" are implemented for settings.debug.revertStrings for now."
+					"Only \"default\", \"strip\" and \"debug\" are implemented for settings.debug.revertStrings for now."
 				);
 			ret.revertStrings = *revertStrings;
 		}
diff --git a/solc/CommandLineInterface.cpp b/solc/CommandLineInterface.cpp
index 1598bbb68..57cdaf943 100644
--- a/solc/CommandLineInterface.cpp
+++ b/solc/CommandLineInterface.cpp
@@ -875,9 +875,9 @@ Allowed options)",
 			serr() << "Invalid option for --" << g_strRevertStrings << ": " << revertStringsString << endl;
 			return false;
 		}
-		if (*revertStrings != RevertStrings::Default && *revertStrings != RevertStrings::Strip)
+		if (*revertStrings == RevertStrings::VerboseDebug)
 		{
-			serr() << "Only \"default\" and \"strip\" are implemented for --" << g_strRevertStrings << " for now." << endl;
+			serr() << "Only \"default\", \"strip\" and \"debug\" are implemented for --" << g_strRevertStrings << " for now." << endl;
 			return false;
 		}
 		m_revertStrings = *revertStrings;
diff --git a/test/libsolidity/Assembly.cpp b/test/libsolidity/Assembly.cpp
index 3c403f74e..f762849e8 100644
--- a/test/libsolidity/Assembly.cpp
+++ b/test/libsolidity/Assembly.cpp
@@ -169,26 +169,32 @@ BOOST_AUTO_TEST_CASE(location_test)
 	if (solidity::test::CommonOptions::get().optimize)
 		locations =
 			vector<SourceLocation>(4, SourceLocation{2, 82, sourceCode}) +
-			vector<SourceLocation>(1, SourceLocation{8, 17, codegenCharStream}) +
-			vector<SourceLocation>(3, SourceLocation{5, 7, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{30, 31, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{5, 14, codegenCharStream}) +
+			vector<SourceLocation>(3, SourceLocation{2, 4, codegenCharStream}) +
 			vector<SourceLocation>(1, SourceLocation{27, 28, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{20, 32, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{5, 7, codegenCharStream}) +
-			vector<SourceLocation>(19, SourceLocation{2, 82, sourceCode}) +
+			vector<SourceLocation>(1, SourceLocation{24, 25, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{17, 29, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{2, 4, codegenCharStream}) +
+			vector<SourceLocation>(16, SourceLocation{2, 82, sourceCode}) +
+			vector<SourceLocation>(1, SourceLocation{12, 13, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{9, 10, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{2, 14, codegenCharStream}) +
 			vector<SourceLocation>(21, SourceLocation{20, 79, sourceCode}) +
 			vector<SourceLocation>(1, SourceLocation{72, 74, sourceCode}) +
 			vector<SourceLocation>(2, SourceLocation{20, 79, sourceCode});
 	else
 		locations =
 			vector<SourceLocation>(4, SourceLocation{2, 82, sourceCode}) +
-			vector<SourceLocation>(1, SourceLocation{8, 17, codegenCharStream}) +
-			vector<SourceLocation>(3, SourceLocation{5, 7, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{30, 31, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{5, 14, codegenCharStream}) +
+			vector<SourceLocation>(3, SourceLocation{2, 4, codegenCharStream}) +
 			vector<SourceLocation>(1, SourceLocation{27, 28, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{20, 32, codegenCharStream}) +
-			vector<SourceLocation>(1, SourceLocation{5, 7, codegenCharStream}) +
-			vector<SourceLocation>(hasShifts ? 19 : 20, SourceLocation{2, 82, sourceCode}) +
+			vector<SourceLocation>(1, SourceLocation{24, 25, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{17, 29, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{2, 4, codegenCharStream}) +
+			vector<SourceLocation>(hasShifts ? 16 : 17, SourceLocation{2, 82, sourceCode}) +
+			vector<SourceLocation>(1, SourceLocation{12, 13, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{9, 10, codegenCharStream}) +
+			vector<SourceLocation>(1, SourceLocation{2, 14, codegenCharStream}) +
 			vector<SourceLocation>(24, SourceLocation{20, 79, sourceCode}) +
 			vector<SourceLocation>(1, SourceLocation{49, 58, sourceCode}) +
 			vector<SourceLocation>(1, SourceLocation{72, 74, sourceCode}) +
diff --git a/test/libsolidity/SemanticTest.cpp b/test/libsolidity/SemanticTest.cpp
index 027fcf1a0..f083fae76 100644
--- a/test/libsolidity/SemanticTest.cpp
+++ b/test/libsolidity/SemanticTest.cpp
@@ -70,6 +70,16 @@ SemanticTest::SemanticTest(string const& _filename, langutil::EVMVersion _evmVer
 		}
 		m_settings.erase("ABIEncoderV1Only");
 	}
+
+	if (m_settings.count("revertStrings"))
+	{
+		auto revertStrings = revertStringsFromString(m_settings["revertStrings"]);
+		if (revertStrings)
+			m_revertStrings = *revertStrings;
+		m_validatedSettings["revertStrings"] = revertStringsToString(m_revertStrings);
+		m_settings.erase("revertStrings");
+	}
+
 	parseExpectations(file);
 	soltestAssert(!m_tests.empty(), "No tests specified in " + _filename);
 }
diff --git a/test/libsolidity/SolidityExecutionFramework.cpp b/test/libsolidity/SolidityExecutionFramework.cpp
index 8f428f13f..dcfb3e6bf 100644
--- a/test/libsolidity/SolidityExecutionFramework.cpp
+++ b/test/libsolidity/SolidityExecutionFramework.cpp
@@ -51,6 +51,7 @@ bytes SolidityExecutionFramework::compileContract(
 	m_compiler.setEVMVersion(m_evmVersion);
 	m_compiler.setOptimiserSettings(m_optimiserSettings);
 	m_compiler.enableIRGeneration(m_compileViaYul);
+	m_compiler.setRevertStringBehaviour(m_revertStrings);
 	if (!m_compiler.compile())
 	{
 		langutil::SourceReferenceFormatter formatter(std::cerr);
diff --git a/test/libsolidity/SolidityExecutionFramework.h b/test/libsolidity/SolidityExecutionFramework.h
index 28246a26c..dfcf4a46b 100644
--- a/test/libsolidity/SolidityExecutionFramework.h
+++ b/test/libsolidity/SolidityExecutionFramework.h
@@ -27,6 +27,7 @@
 #include <test/ExecutionFramework.h>
 
 #include <libsolidity/interface/CompilerStack.h>
+#include <libsolidity/interface/DebugSettings.h>
 
 #include <libyul/AssemblyStack.h>
 
@@ -67,6 +68,8 @@ public:
 protected:
 	solidity::frontend::CompilerStack m_compiler;
 	bool m_compileViaYul = false;
+	RevertStrings m_revertStrings = RevertStrings::Default;
+
 };
 
 } // end namespaces
diff --git a/test/libsolidity/SolidityExpressionCompiler.cpp b/test/libsolidity/SolidityExpressionCompiler.cpp
index 0cafe42a4..cb0066bee 100644
--- a/test/libsolidity/SolidityExpressionCompiler.cpp
+++ b/test/libsolidity/SolidityExpressionCompiler.cpp
@@ -139,7 +139,10 @@ bytes compileFirstExpression(
 			FirstExpressionExtractor extractor(*contract);
 			BOOST_REQUIRE(extractor.expression() != nullptr);
 
-			CompilerContext context(solidity::test::CommonOptions::get().evmVersion());
+			CompilerContext context(
+				solidity::test::CommonOptions::get().evmVersion(),
+				RevertStrings::Default
+			);
 			context.resetVisitedNodes(contract);
 			context.setInheritanceHierarchy(inheritanceHierarchy);
 			unsigned parametersSize = _localVariables.size(); // assume they are all one slot on the stack
@@ -152,7 +155,6 @@ bytes compileFirstExpression(
 
 			ExpressionCompiler(
 				context,
-				RevertStrings::Default,
 				solidity::test::CommonOptions::get().optimize
 			).compile(*extractor.expression());
 
diff --git a/test/libsolidity/StandardCompiler.cpp b/test/libsolidity/StandardCompiler.cpp
index 31c37060a..6ade0849f 100644
--- a/test/libsolidity/StandardCompiler.cpp
+++ b/test/libsolidity/StandardCompiler.cpp
@@ -366,14 +366,15 @@ BOOST_AUTO_TEST_CASE(basic_compilation)
 	BOOST_CHECK(contract["evm"]["assembly"].isString());
 	BOOST_CHECK(contract["evm"]["assembly"].asString().find(
 		"    /* \"fileA\":0:14  contract A { } */\n  mstore(0x40, 0x80)\n  "
-		"callvalue\n    /* \"--CODEGEN--\":8:17   */\n  dup1\n    "
-		"/* \"--CODEGEN--\":5:7   */\n  iszero\n  tag_1\n  jumpi\n    "
-		"/* \"--CODEGEN--\":30:31   */\n  0x00\n    /* \"--CODEGEN--\":27:28   */\n  "
-		"dup1\n    /* \"--CODEGEN--\":20:32   */\n  revert\n    /* \"--CODEGEN--\":5:7   */\n"
+		"callvalue\n    /* \"--CODEGEN--\":5:14   */\n  dup1\n    "
+		"/* \"--CODEGEN--\":2:4   */\n  iszero\n  tag_1\n  jumpi\n    "
+		"/* \"--CODEGEN--\":27:28   */\n  0x00\n    /* \"--CODEGEN--\":24:25   */\n  "
+		"dup1\n    /* \"--CODEGEN--\":17:29   */\n  revert\n    /* \"--CODEGEN--\":2:4   */\n"
 		"tag_1:\n    /* \"fileA\":0:14  contract A { } */\n  pop\n  dataSize(sub_0)\n  dup1\n  "
 		"dataOffset(sub_0)\n  0x00\n  codecopy\n  0x00\n  return\nstop\n\nsub_0: assembly {\n        "
-		"/* \"fileA\":0:14  contract A { } */\n      mstore(0x40, 0x80)\n      0x00\n      "
-		"dup1\n      revert\n\n    auxdata: 0xa26469706673582212"
+		"/* \"fileA\":0:14  contract A { } */\n      mstore(0x40, 0x80)\n        "
+		"/* \"--CODEGEN--\":12:13   */\n      0x00\n        /* \"--CODEGEN--\":9:10   */\n      "
+		"dup1\n        /* \"--CODEGEN--\":2:14   */\n      revert\n\n    auxdata: 0xa26469706673582212"
 	) == 0);
 	BOOST_CHECK(contract["evm"]["gasEstimates"].isObject());
 	BOOST_CHECK_EQUAL(contract["evm"]["gasEstimates"].size(), 1);
@@ -397,15 +398,15 @@ BOOST_AUTO_TEST_CASE(basic_compilation)
 		"{\"begin\":0,\"end\":14,\"name\":\"PUSH\",\"value\":\"40\"},"
 		"{\"begin\":0,\"end\":14,\"name\":\"MSTORE\"},"
 		"{\"begin\":0,\"end\":14,\"name\":\"CALLVALUE\"},"
-		"{\"begin\":8,\"end\":17,\"name\":\"DUP1\"},"
-		"{\"begin\":5,\"end\":7,\"name\":\"ISZERO\"},"
-		"{\"begin\":5,\"end\":7,\"name\":\"PUSH [tag]\",\"value\":\"1\"},"
-		"{\"begin\":5,\"end\":7,\"name\":\"JUMPI\"},"
-		"{\"begin\":30,\"end\":31,\"name\":\"PUSH\",\"value\":\"0\"},"
-		"{\"begin\":27,\"end\":28,\"name\":\"DUP1\"},"
-		"{\"begin\":20,\"end\":32,\"name\":\"REVERT\"},"
-		"{\"begin\":5,\"end\":7,\"name\":\"tag\",\"value\":\"1\"},"
-		"{\"begin\":5,\"end\":7,\"name\":\"JUMPDEST\"},"
+		"{\"begin\":5,\"end\":14,\"name\":\"DUP1\"},"
+		"{\"begin\":2,\"end\":4,\"name\":\"ISZERO\"},"
+		"{\"begin\":2,\"end\":4,\"name\":\"PUSH [tag]\",\"value\":\"1\"},"
+		"{\"begin\":2,\"end\":4,\"name\":\"JUMPI\"},"
+		"{\"begin\":27,\"end\":28,\"name\":\"PUSH\",\"value\":\"0\"},"
+		"{\"begin\":24,\"end\":25,\"name\":\"DUP1\"},"
+		"{\"begin\":17,\"end\":29,\"name\":\"REVERT\"},"
+		"{\"begin\":2,\"end\":4,\"name\":\"tag\",\"value\":\"1\"},"
+		"{\"begin\":2,\"end\":4,\"name\":\"JUMPDEST\"},"
 		"{\"begin\":0,\"end\":14,\"name\":\"POP\"},"
 		"{\"begin\":0,\"end\":14,\"name\":\"PUSH #[$]\",\"value\":\"0000000000000000000000000000000000000000000000000000000000000000\"},"
 		"{\"begin\":0,\"end\":14,\"name\":\"DUP1\"},"
diff --git a/test/libsolidity/semanticTests/revertStrings/array_slices.sol b/test/libsolidity/semanticTests/revertStrings/array_slices.sol
new file mode 100644
index 000000000..dec3e916d
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/array_slices.sol
@@ -0,0 +1,11 @@
+contract C {
+	function f(uint256 start, uint256 end, uint256[] calldata arr) external pure {
+		arr[start:end];
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256,uint256,uint256[]): 2, 1, 0x80, 3, 1, 2, 3 -> FAILURE, hex"08c379a0", 0x20, 22, "Slice starts after end"
+// f(uint256,uint256,uint256[]): 1, 5, 0x80, 3, 1, 2, 3 -> FAILURE, hex"08c379a0", 0x20, 28, "Slice is greater than length"
diff --git a/test/libsolidity/semanticTests/revertStrings/bubble.sol b/test/libsolidity/semanticTests/revertStrings/bubble.sol
new file mode 100644
index 000000000..5e9a0730d
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/bubble.sol
@@ -0,0 +1,15 @@
+contract A {
+	function g() public { revert("fail"); }
+}
+
+contract C {
+	A a = new A();
+	function f() public {
+		a.g();
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f() -> FAILURE, hex"08c379a0", 0x20, 4, "fail"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_invalid.sol b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_invalid.sol
new file mode 100644
index 000000000..2538a2175
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_invalid.sol
@@ -0,0 +1,11 @@
+pragma experimental ABIEncoderV2;
+contract C {
+	function f(uint256[][] calldata a) external returns (uint) {
+		return 42;
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256[][]): 0x20, 1 -> FAILURE, hex"08c379a0", 0x20, 43, "ABI decoding: invalid calldata a", "rray stride"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_decode.sol b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_decode.sol
new file mode 100644
index 000000000..9f9296d2a
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_decode.sol
@@ -0,0 +1,12 @@
+pragma experimental ABIEncoderV2;
+contract C {
+    function f(uint256[][2][] calldata x) external returns (uint256) {
+        x[0];
+        return 23;
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256[][2][]): 0x20, 0x01, 0x20, 0x00 -> FAILURE, hex"08c379a0", 0x20, 28, "Invalid calldata tail offset"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_reencode.sol b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_reencode.sol
new file mode 100644
index 000000000..7aac0f7f8
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_array_dynamic_static_short_reencode.sol
@@ -0,0 +1,14 @@
+pragma experimental ABIEncoderV2;
+contract C {
+    function f(uint256[][2][] calldata x) external returns (uint256) {
+        return 42;
+    }
+    function g(uint256[][2][] calldata x) external returns (uint256) {
+        return this.f(x);
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// g(uint256[][2][]): 0x20, 0x01, 0x20, 0x00 -> FAILURE, hex"08c379a0", 0x20, 30, "Invalid calldata access offset"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_array_invalid_length.sol b/test/libsolidity/semanticTests/revertStrings/calldata_array_invalid_length.sol
new file mode 100644
index 000000000..3b68bacea
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_array_invalid_length.sol
@@ -0,0 +1,11 @@
+pragma experimental ABIEncoderV2;
+contract C {
+	function f(uint256[][] calldata x) external returns (uint256) {
+		return x[0].length;
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256[][]): 0x20, 1, 0x20, 0x0100000000000000000000 -> FAILURE, hex"08c379a0", 0x20, 28, "Invalid calldata tail length"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_arrays_too_large.sol b/test/libsolidity/semanticTests/revertStrings/calldata_arrays_too_large.sol
new file mode 100644
index 000000000..52809a0b2
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_arrays_too_large.sol
@@ -0,0 +1,11 @@
+pragma experimental ABIEncoderV2;
+contract C {
+	function f(uint a, uint[] calldata b, uint c) external pure returns (uint) {
+		return 7;
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256,uint256[],uint256): 6, 0x60, 9, 0x1000000000000000000000000000000000000000000000000000000000000002, 1, 2 -> FAILURE, hex"08c379a0", 0x20, 43, "ABI decoding: invalid calldata a", "rray length"
diff --git a/test/libsolidity/semanticTests/revertStrings/calldata_too_short.sol b/test/libsolidity/semanticTests/revertStrings/calldata_too_short.sol
new file mode 100644
index 000000000..fea9fe72c
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/calldata_too_short.sol
@@ -0,0 +1,11 @@
+contract C {
+	function d(bytes memory _data) public pure returns (uint8) {
+		return abi.decode(_data, (uint8));
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ABIEncoderV1Only: true
+// ----
+// d(bytes): 0x20, 0x01, 0x0000000000000000000000000000000000000000000000000000000000000000 -> FAILURE, hex"08c379a0", 0x20, 18, "Calldata too short"
diff --git a/test/libsolidity/semanticTests/revertStrings/called_contract_has_code.sol b/test/libsolidity/semanticTests/revertStrings/called_contract_has_code.sol
new file mode 100644
index 000000000..b21f85cc8
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/called_contract_has_code.sol
@@ -0,0 +1,12 @@
+contract C {
+	function f() external {}
+	function g() external {
+		C c = C(0x0000000000000000000000000000000000000000000000000000000000000000);
+		c.f();
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// g() -> FAILURE, hex"08c379a0", 0x20, 37, "Target contract does not contain", " code"
diff --git a/test/libsolidity/semanticTests/revertStrings/enum.sol b/test/libsolidity/semanticTests/revertStrings/enum.sol
new file mode 100644
index 000000000..db3f9f7e2
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/enum.sol
@@ -0,0 +1,12 @@
+contract C {
+	enum E {X, Y}
+	function f(E[] calldata arr) external {
+		arr[1];
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ABIEncoderV1Only: true
+// ----
+// f(uint8[]): 0x20, 2, 3, 3 -> FAILURE, hex"08c379a0", 0x20, 17, "Enum out of range"
diff --git a/test/libsolidity/semanticTests/revertStrings/ether_non_payable_function.sol b/test/libsolidity/semanticTests/revertStrings/ether_non_payable_function.sol
new file mode 100644
index 000000000..ffaea6878
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/ether_non_payable_function.sol
@@ -0,0 +1,9 @@
+contract C {
+	function f() public {}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(), 1 ether -> FAILURE, hex"08c379a0", 0x20, 34, "Ether sent to non-payable functi", "on"
+// () -> FAILURE, hex"08c379a0", 0x20, 53, "Contract does not have fallback ", "nor receive functions"
diff --git a/test/libsolidity/semanticTests/revertStrings/function_entry_checks.sol b/test/libsolidity/semanticTests/revertStrings/function_entry_checks.sol
new file mode 100644
index 000000000..4072db952
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/function_entry_checks.sol
@@ -0,0 +1,9 @@
+contract C {
+    function t(uint) public pure {}
+}
+// ====
+// EVMVersion: >=byzantium
+// compileViaYul: true
+// revertStrings: debug
+// ----
+// t(uint256) -> FAILURE, hex"08c379a0", 0x20, 34, "ABI decoding: tuple data too sho", "rt"
diff --git a/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_calldata_v1.sol b/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_calldata_v1.sol
new file mode 100644
index 000000000..3468bfc07
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_calldata_v1.sol
@@ -0,0 +1,13 @@
+contract C {
+	function d(bytes memory _data) public pure returns (uint8) {
+		return abi.decode(_data, (uint8));
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ABIEncoderV1Only: true
+// ----
+// d(bytes): 0x20, 0x20, 0x0000000000000000000000000000000000000000000000000000000000000000 -> 0
+// d(bytes): 0x100, 0x20, 0x0000000000000000000000000000000000000000000000000000000000000000 -> FAILURE, hex"08c379a0", 0x20, 43, "ABI calldata decoding: invalid h", "ead pointer"
+// d(bytes): 0x20, 0x100, 0x0000000000000000000000000000000000000000000000000000000000000000 -> FAILURE, hex"08c379a0", 0x20, 43, "ABI calldata decoding: invalid d", "ata pointer"
diff --git a/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_memory_v1.sol b/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_memory_v1.sol
new file mode 100644
index 000000000..68981a3cb
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/invalid_abi_decoding_memory_v1.sol
@@ -0,0 +1,20 @@
+contract C {
+	function dyn(uint ptr, uint start, uint x) public returns (bytes memory a) {
+		assembly {
+			mstore(0, start)
+			mstore(start, add(start, 1))
+			return(ptr, x)
+		}
+	}
+	function f(uint ptr, uint start, uint x) public returns (bool) {
+		this.dyn(ptr, start, x);
+		return true;
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ABIEncoderV1Only: true
+// ----
+// f(uint256,uint256,uint256): 0, 0x200, 0x60 -> FAILURE, hex"08c379a0", 0x20, 39, "ABI memory decoding: invalid dat", "a start"
+// f(uint256,uint256,uint256): 0, 0x20, 0x60 -> FAILURE, hex"08c379a0", 0x20, 40, "ABI memory decoding: invalid dat", "a length"
diff --git a/test/libsolidity/semanticTests/revertStrings/library_non_view_call.sol b/test/libsolidity/semanticTests/revertStrings/library_non_view_call.sol
new file mode 100644
index 000000000..1a079a04a
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/library_non_view_call.sol
@@ -0,0 +1,16 @@
+library L {
+    function g() external {}
+}
+contract C {
+    function f() public returns (bytes memory) {
+        (bool success, bytes memory result) = address(L).call(abi.encodeWithSignature("g()"));
+		assert(!success);
+		return result;
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// library: L
+// f() -> 32, 132, 3963877391197344453575983046348115674221700746820753546331534351508065746944, 862718293348820473429344482784628181556388621521298319395315527974912, 1518017211910606845658622928256476421055725129218887721595913401102969, 14649601406562900601407788686537400806574002225747213573947654179243427889152, 0
diff --git a/test/libsolidity/semanticTests/revertStrings/short_input_array.sol b/test/libsolidity/semanticTests/revertStrings/short_input_array.sol
new file mode 100644
index 000000000..1a80acc26
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/short_input_array.sol
@@ -0,0 +1,9 @@
+pragma experimental ABIEncoderV2;
+contract C {
+	function f(uint[] memory a) public pure returns (uint) { return 7; }
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// f(uint256[]): 0x20, 1 -> FAILURE, hex"08c379a0", 0x20, 43, "ABI decoding: invalid calldata a", "rray stride"
diff --git a/test/libsolidity/semanticTests/revertStrings/short_input_bytes.sol b/test/libsolidity/semanticTests/revertStrings/short_input_bytes.sol
new file mode 100644
index 000000000..f361da7b6
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/short_input_bytes.sol
@@ -0,0 +1,9 @@
+pragma experimental ABIEncoderV2;
+contract C {
+	function e(bytes memory a) public pure returns (uint) { return 7; }
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// e(bytes): 0x20, 7 -> FAILURE, hex"08c379a0", 0x20, 39, "ABI decoding: invalid byte array", " length"
diff --git a/test/libsolidity/semanticTests/revertStrings/transfer.sol b/test/libsolidity/semanticTests/revertStrings/transfer.sol
new file mode 100644
index 000000000..fcf971a5c
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/transfer.sol
@@ -0,0 +1,27 @@
+contract A {
+	receive() external payable {
+		revert("no_receive");
+	}
+}
+
+contract C {
+	A a = new A();
+	receive() external payable {}
+	function f() public {
+		address(a).transfer(1 wei);
+	}
+	function h() public {
+		address(a).transfer(100 ether);
+	}
+	function g() public view returns (uint) {
+		return address(this).balance;
+	}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// (), 10 ether ->
+// g() -> 10
+// f() -> FAILURE, hex"08c379a0", 0x20, 10, "no_receive"
+// h() -> FAILURE
diff --git a/test/libsolidity/semanticTests/revertStrings/unknown_sig_no_fallback.sol b/test/libsolidity/semanticTests/revertStrings/unknown_sig_no_fallback.sol
new file mode 100644
index 000000000..62b245885
--- /dev/null
+++ b/test/libsolidity/semanticTests/revertStrings/unknown_sig_no_fallback.sol
@@ -0,0 +1,8 @@
+contract A {
+	receive () external payable {}
+}
+// ====
+// EVMVersion: >=byzantium
+// revertStrings: debug
+// ----
+// (): hex"00" -> FAILURE, hex"08c379a0", 0x20, 41, "Unknown signature and no fallbac", "k defined"