Disallow remappings with empty prefix.

libsolidity/interface/CompilerStack.cpp

@@ -58,22 +58,31 @@ using namespace std;
 using namespace dev;
 using namespace dev::solidity;
 
-void CompilerStack::setRemappings(vector<string> const& _remappings)
+boost::optional<CompilerStack::Remapping> CompilerStack::parseRemapping(string const& _remapping)
+{
+	auto eq = find(_remapping.begin(), _remapping.end(), '=');
+	if (eq == _remapping.end())
+		return {};
+
+	auto colon = find(_remapping.begin(), eq, ':');
+
+	Remapping r;
+
+	r.context = colon == eq ? string() : string(_remapping.begin(), colon);
+	r.prefix = colon == eq ? string(_remapping.begin(), eq) : string(colon + 1, eq);
+	r.target = string(eq + 1, _remapping.end());
+
+	if (r.prefix.empty())
+		return {};
+
+	return r;
+}
+
+void CompilerStack::setRemappings(vector<Remapping> const& _remappings)
 {
-	vector<Remapping> remappings;
 	for (auto const& remapping: _remappings)
-	{
-		auto eq = find(remapping.begin(), remapping.end(), '=');
-		if (eq == remapping.end())
-			continue; // ignore
-		auto colon = find(remapping.begin(), eq, ':');
-		Remapping r;
-		r.context = colon == eq ? string() : string(remapping.begin(), colon);
-		r.prefix = colon == eq ? string(remapping.begin(), eq) : string(colon + 1, eq);
-		r.target = string(eq + 1, remapping.end());
-		remappings.push_back(r);
-	}
-	swap(m_remappings, remappings);
+		solAssert(!remapping.prefix.empty(), "");
+	m_remappings = _remappings;
 }
 
 void CompilerStack::setEVMVersion(EVMVersion _version)

libsolidity/interface/CompilerStack.h

@@ -84,6 +84,13 @@ public:
 		CompilationSuccessful
 	};
 
+	struct Remapping
+	{
+		std::string context;
+		std::string prefix;
+		std::string target;
+	};
+
 	/// Creates a new compiler stack.
 	/// @param _readFile callback to used to read files for import statements. Must return
 	/// and must not emit exceptions.
@@ -103,8 +110,11 @@ public:
 	/// All settings, with the exception of remappings, are reset.
 	void reset(bool _keepSources = false);
 
-	/// Sets path remappings in the format "context:prefix=target"
-	void setRemappings(std::vector<std::string> const& _remappings);
+	// Parses a remapping of the format "context:prefix=target".
+	static boost::optional<Remapping> parseRemapping(std::string const& _remapping);
+
+	/// Sets path remappings.
+	void setRemappings(std::vector<Remapping> const& _remappings);
 
 	/// Sets library addresses. Addresses are cleared iff @a _libraries is missing.
 	/// Will not take effect before running compile.
@@ -319,13 +329,6 @@ private:
 		FunctionDefinition const& _function
 	) const;
 
-	struct Remapping
-	{
-		std::string context;
-		std::string prefix;
-		std::string target;
-	};
-
 	ReadCallback::Callback m_readFile;
 	ReadCallback::Callback m_smtQuery;
 	bool m_optimize = false;

libsolidity/interface/StandardCompiler.cpp

@@ -326,9 +326,14 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 		m_compilerStack.setEVMVersion(*version);
 	}
 
-	vector<string> remappings;
+	vector<CompilerStack::Remapping> remappings;
 	for (auto const& remapping: settings.get("remappings", Json::Value()))
-		remappings.push_back(remapping.asString());
+	{
+		if (auto r = CompilerStack::parseRemapping(remapping.asString()))
+			remappings.emplace_back(std::move(*r));
+		else
+			return formatFatalError("JSONError", "Invalid remapping: \"" + remapping.asString() + "\"");
+	}
 	m_compilerStack.setRemappings(remappings);
 
 	Json::Value optimizerSettings = settings.get("optimizer", Json::Value());