4 files changed, 150 insertions, 13 deletions
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index effc8309..92b49cda 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -38,6 +38,7 @@
 #include <libsolidity/analysis/SyntaxChecker.h>
 #include <libsolidity/codegen/Compiler.h>
 #include <libsolidity/interface/InterfaceHandler.h>
+#include <libsolidity/interface/GasEstimator.h>
 #include <libsolidity/formal/Why3Translator.h>
 
 #include <libevmasm/Exceptions.h>
@@ -55,7 +56,7 @@ using namespace std;
 using namespace dev;
 using namespace dev::solidity;
 
-CompilerStack::CompilerStack(ReadFileCallback const& _readFile):
+CompilerStack::CompilerStack(ReadFile::Callback const& _readFile):
 	m_readFile(_readFile), m_parseSuccessful(false) {}
 
 void CompilerStack::setRemappings(vector<string> const& _remappings)
@@ -522,7 +523,7 @@ StringMap CompilerStack::loadMissingSources(SourceUnit const& _ast, std::string
 			if (m_sources.count(importPath) || newSources.count(importPath))
 				continue;
 
-			ReadFileResult result{false, string("File not supplied initially.")};
+			ReadFile::Result result{false, string("File not supplied initially.")};
 			if (m_readFile)
 				result = m_readFile(importPath);
 
@@ -841,3 +842,88 @@ string CompilerStack::computeSourceMapping(eth::AssemblyItems const& _items) con
 	}
 	return ret;
 }
+
+namespace
+{
+
+Json::Value gasToJson(GasEstimator::GasConsumption const& _gas)
+{
+	if (_gas.isInfinite)
+		return Json::Value("infinite");
+	else
+		return Json::Value(toString(_gas.value));
+}
+
+}
+
+Json::Value CompilerStack::gasEstimates(string const& _contractName) const
+{
+	if (!assemblyItems(_contractName) && !runtimeAssemblyItems(_contractName))
+		return Json::Value();
+
+	using Gas = GasEstimator::GasConsumption;
+	Json::Value output(Json::objectValue);
+
+	if (eth::AssemblyItems const* items = assemblyItems(_contractName))
+	{
+		Gas executionGas = GasEstimator::functionalEstimation(*items);
+		u256 bytecodeSize(runtimeObject(_contractName).bytecode.size());
+		Gas codeDepositGas = bytecodeSize * eth::GasCosts::createDataGas;
+
+		Json::Value creation(Json::objectValue);
+		creation["codeDepositCost"] = gasToJson(codeDepositGas);
+		creation["executionCost"] = gasToJson(executionGas);
+		/// TODO: implement + overload to avoid the need of +=
+		executionGas += codeDepositGas;
+		creation["totalCost"] = gasToJson(executionGas);
+		output["creation"] = creation;
+	}
+
+	if (eth::AssemblyItems const* items = runtimeAssemblyItems(_contractName))
+	{
+		/// External functions
+		ContractDefinition const& contract = contractDefinition(_contractName);
+		Json::Value externalFunctions(Json::objectValue);
+		for (auto it: contract.interfaceFunctions())
+		{
+			string sig = it.second->externalSignature();
+			externalFunctions[sig] = gasToJson(GasEstimator::functionalEstimation(*items, sig));
+		}
+
+		if (contract.fallbackFunction())
+			/// This needs to be set to an invalid signature in order to trigger the fallback,
+			/// without the shortcut (of CALLDATSIZE == 0), and therefore to receive the upper bound.
+			/// An empty string ("") would work to trigger the shortcut only.
+			externalFunctions[""] = gasToJson(GasEstimator::functionalEstimation(*items, "INVALID"));
+
+		if (!externalFunctions.empty())
+			output["external"] = externalFunctions;
+
+		/// Internal functions
+		Json::Value internalFunctions(Json::objectValue);
+		for (auto const& it: contract.definedFunctions())
+		{
+			/// Exclude externally visible functions, constructor and the fallback function
+			if (it->isPartOfExternalInterface() || it->isConstructor() || it->name().empty())
+				continue;
+
+			size_t entry = functionEntryPoint(_contractName, *it);
+			GasEstimator::GasConsumption gas = GasEstimator::GasConsumption::infinite();
+			if (entry > 0)
+				gas = GasEstimator::functionalEstimation(*items, entry, *it);
+
+			FunctionType type(*it);
+			string sig = it->name() + "(";
+			auto paramTypes = type.parameterTypes();
+			for (auto it = paramTypes.begin(); it != paramTypes.end(); ++it)
+				sig += (*it)->toString() + (it + 1 == paramTypes.end() ? "" : ",");
+			sig += ")";
+			internalFunctions[sig] = gasToJson(gas);
+		}
+
+		if (!internalFunctions.empty())
+			output["internal"] = internalFunctions;
+	}
+
+	return output;
+}
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index 65850683..a34a34bb 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -36,6 +36,7 @@
 #include <libevmasm/SourceLocation.h>
 #include <libevmasm/LinkerObject.h>
 #include <libsolidity/interface/Exceptions.h>
+#include <libsolidity/interface/ReadFile.h>
 
 namespace dev
 {
@@ -77,18 +78,9 @@ enum class DocumentationType: uint8_t
 class CompilerStack: boost::noncopyable
 {
 public:
-	struct ReadFileResult
-	{
-		bool success;
-		std::string contentsOrErrorMessage;
-	};
-
-	/// File reading callback.
-	using ReadFileCallback = std::function<ReadFileResult(std::string const&)>;
-
 	/// Creates a new compiler stack.
 	/// @param _readFile callback to used to read files for import statements. Should return
-	explicit CompilerStack(ReadFileCallback const& _readFile = ReadFileCallback());
+	explicit CompilerStack(ReadFile::Callback const& _readFile = ReadFile::Callback());
 
 	/// Sets path remappings in the format "context:prefix=target"
 	void setRemappings(std::vector<std::string> const& _remappings);
@@ -181,6 +173,9 @@ public:
 	std::string const& onChainMetadata(std::string const& _contractName) const;
 	void useMetadataLiteralSources(bool _metadataLiteralSources) { m_metadataLiteralSources = _metadataLiteralSources; }
 
+	/// @returns a JSON representing the estimated gas usage for contract creation, internal and external functions
+	Json::Value gasEstimates(std::string const& _contractName) const;
+
 	/// @returns the previously used scanner, useful for counting lines during error reporting.
 	Scanner const& scanner(std::string const& _sourceName = "") const;
 	/// @returns the parsed source unit with the supplied name.
@@ -263,7 +258,7 @@ private:
 		std::string target;
 	};
 
-	ReadFileCallback m_readFile;
+	ReadFile::Callback m_readFile;
 	bool m_optimize = false;
 	unsigned m_optimizeRuns = 200;
 	std::map<std::string, h160> m_libraries;
diff --git a/libsolidity/interface/ReadFile.h b/libsolidity/interface/ReadFile.h
new file mode 100644
index 00000000..2e8a6bd8
--- /dev/null
+++ b/libsolidity/interface/ReadFile.h
@@ -0,0 +1,45 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include <string>
+#include <functional>
+#include <boost/noncopyable.hpp>
+
+namespace dev
+{
+
+namespace solidity
+{
+
+class ReadFile: boost::noncopyable
+{
+public:
+	/// File reading result.
+	struct Result
+	{
+		bool success;
+		std::string contentsOrErrorMessage;
+	};
+
+	/// File reading callback.
+	using Callback = std::function<Result(std::string const&)>;
+};
+
+}
+}
diff --git a/libsolidity/interface/SourceReferenceFormatter.h b/libsolidity/interface/SourceReferenceFormatter.h
index 7034f4ab..e8676d60 100644
--- a/libsolidity/interface/SourceReferenceFormatter.h
+++ b/libsolidity/interface/SourceReferenceFormatter.h
@@ -23,6 +23,7 @@
 #pragma once
 
 #include <ostream>
+#include <sstream>
 #include <functional>
 #include <libevmasm/SourceLocation.h>
 
@@ -53,6 +54,16 @@ public:
 		std::string const& _name,
 		ScannerFromSourceNameFun const& _scannerFromSourceName
 	);
+	static std::string formatExceptionInformation(
+		Exception const& _exception,
+		std::string const& _name,
+		ScannerFromSourceNameFun const& _scannerFromSourceName
+	)
+	{
+		std::ostringstream errorOutput;
+		printExceptionInformation(errorOutput, _exception, _name, _scannerFromSourceName);
+		return errorOutput.str();
+	}
 private:
 	/// Prints source name if location is given.
 	static void printSourceName(