added interface function for SourceLocation/ position convertation to compilerstack

libsolidity/CompilerStack.cpp

@@ -257,6 +257,15 @@ bytes CompilerStack::staticCompile(std::string const& _sourceCode, bool _optimiz
 	return stack.compile(_sourceCode, _optimize);
 }
 
+pair<int, int> CompilerStack::positionFromSourceLocation(SourceLocation const& _sourceLocation) const
+{
+	int initLine;
+	int initColumn;
+	tie(initLine, initColumn) = getScanner(*_sourceLocation.sourceName).translatePositionToLineColumn(_sourceLocation.start);
+
+	return make_pair(++initLine, ++initColumn);
+}
+
 void CompilerStack::reset(bool _keepSources)
 {
 	m_parseSuccessful = false;

libsolidity/CompilerStack.h

@@ -31,6 +31,7 @@
 #include <json/json.h>
 #include <libdevcore/Common.h>
 #include <libdevcore/FixedHash.h>
+#include <libevmasm/SourceLocation.h>
 
 namespace dev
 {
@@ -131,6 +132,9 @@ public:
 	/// scanning the source code - this is useful for printing exception information.
 	static bytes staticCompile(std::string const& _sourceCode, bool _optimize = false);
 
+	/// helper function for printing logs. Do only use in error cases, it's quite expensive.
+	std::pair<int, int> positionFromSourceLocation(SourceLocation const& _sourceLocation) const;
+
 private:
 	/**
 	 * Information pertaining to one source unit, filled gradually during parsing and compilation.