liblangutil: refactors SourceReferenceFormatter error formatting for pretty and colored output.

* Refactors output format in a way it is (or should at least be) more readable.
  (NB.: As source of inspiration, I chose the rustc compiler output.)
* Adds color support to the stream output.
* Also improves multiline source formatting
  (i.e. truncating too long lines, like done with single lines already)
* solc: adds flags --color (force terminal colors) and --no-color (disable autodetection)
* solc: adds --new-reporter to give output in *new* formatting (colored or not)
* Changelog adapted accordingly.

Author: Christian Parpart

Changelog.md

@@ -13,7 +13,8 @@ Language Features:
 
 Compiler Features:
  * C API (``libsolc`` / raw ``soljson.js``): Introduce ``solidity_free`` method which releases all internal buffers to save memory.
-
+ * Commandline interface: Adds new option ``--new-reporter`` for improved diagnostics formatting
+   along with ``--color`` and ``--no-color`` for colorized output to be forced (or explicitly disabled).
 
 Bugfixes:
 

liblangutil/CMakeLists.txt

@@ -16,6 +16,8 @@ set(sources
 	SourceReferenceExtractor.h
 	SourceReferenceFormatter.cpp
 	SourceReferenceFormatter.h
+	SourceReferenceFormatterHuman.cpp
+	SourceReferenceFormatterHuman.h
 	Token.cpp
 	Token.h
 	UndefMacros.h

liblangutil/SourceReferenceFormatter.h

@@ -44,11 +44,14 @@ class SourceReferenceFormatter
 		m_stream(_stream)
 	{}
 
+	virtual ~SourceReferenceFormatter() = default;
+
 	/// Prints source location if it is given.
-	void printSourceLocation(SourceLocation const* _location);
-	void printSourceLocation(SourceReference const& _ref);
-	void printExceptionInformation(dev::Exception const& _error, std::string const& _category);
-	void printExceptionInformation(SourceReferenceExtractor::Message const& _msg);
+	virtual void printSourceLocation(SourceReference const& _ref);
+	virtual void printExceptionInformation(SourceReferenceExtractor::Message const& _msg);
+
+	virtual void printSourceLocation(SourceLocation const* _location);
+	virtual void printExceptionInformation(dev::Exception const& _error, std::string const& _category);
 
 	static std::string formatExceptionInformation(
 		dev::Exception const& _exception,
@@ -62,7 +65,7 @@ class SourceReferenceFormatter
 		return errorOutput.str();
 	}
 
-private:
+protected:
 	/// Prints source name if location is given.
 	void printSourceName(SourceReference const& _ref);
 

liblangutil/SourceReferenceFormatterHuman.cpp

@@ -0,0 +1,136 @@
+/*
+	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/>.
+*/
+/**
+ * Formatting functions for errors referencing positions and locations in the source.
+ */
+
+#include <liblangutil/SourceReferenceFormatterHuman.h>
+#include <liblangutil/Scanner.h>
+#include <liblangutil/Exceptions.h>
+#include <cmath>
+#include <iomanip>
+
+using namespace std;
+using namespace dev;
+using namespace dev::formatting;
+using namespace langutil;
+
+AnsiColorized SourceReferenceFormatterHuman::normalColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {WHITE});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::frameColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {BOLD, BLUE});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::errorColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {BOLD, RED});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::messageColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {BOLD, WHITE});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::secondaryColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {BOLD, CYAN});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::highlightColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {YELLOW});
+}
+
+AnsiColorized SourceReferenceFormatterHuman::diagColored() const
+{
+	return AnsiColorized(m_stream, m_colored, {BOLD, YELLOW});
+}
+
+void SourceReferenceFormatterHuman::printSourceLocation(SourceReference const& _ref)
+{
+	if (_ref.position.line < 0)
+		return; // Nothing we can print here
+
+	int const leftpad = static_cast<int>(log10(max(_ref.position.line, 1))) + 1;
+
+	// line 0: source name
+	frameColored() << string(leftpad, ' ') << "--> ";
+	m_stream << _ref.sourceName << ":" << (_ref.position.line + 1) << ":" << (_ref.position.column + 1) << ": " << '\n';
+
+	if (!_ref.multiline)
+	{
+		int const locationLength = _ref.endColumn - _ref.startColumn;
+
+		// line 1:
+		m_stream << string(leftpad, ' ');
+		frameColored() << " |" << '\n';
+
+		// line 2:
+		frameColored() << (_ref.position.line + 1) << " | ";
+		m_stream << _ref.text.substr(0, _ref.startColumn);
+		highlightColored() << _ref.text.substr(_ref.startColumn, locationLength);
+		m_stream << _ref.text.substr(_ref.endColumn) << '\n';
+
+		// line 3:
+		m_stream << string(leftpad, ' ');
+		frameColored() << " | ";
+		for_each(
+			_ref.text.cbegin(),
+			_ref.text.cbegin() + _ref.startColumn,
+			[this](char ch) { m_stream << (ch == '\t' ? '\t' : ' '); }
+		);
+		diagColored() << string(locationLength, '^') << '\n';
+	}
+	else
+	{
+		// line 1:
+		m_stream << string(leftpad, ' ');
+		frameColored() << " |" << '\n';
+
+		// line 2:
+		frameColored() << (_ref.position.line + 1) << " | ";
+		m_stream << _ref.text.substr(0, _ref.startColumn);
+		highlightColored() << _ref.text.substr(_ref.startColumn) << '\n';
+
+		// line 3:
+		frameColored() << string(leftpad, ' ') << " | ";
+		m_stream << string(_ref.startColumn, ' ');
+		diagColored() << "^ (Relevant source part starts here and spans across multiple lines).\n";
+	}
+}
+
+void SourceReferenceFormatterHuman::printExceptionInformation(SourceReferenceExtractor::Message const& _msg)
+{
+	// exception header line
+	errorColored() << _msg.category;
+	messageColored() << ": " << _msg.primary.message << '\n';
+
+	printSourceLocation(_msg.primary);
+
+	for (auto const& secondary: _msg.secondary)
+	{
+		secondaryColored() << "Note";
+		messageColored() << ": " << secondary.message << '\n';
+		printSourceLocation(secondary);
+	}
+
+	m_stream << '\n';
+}

liblangutil/SourceReferenceFormatterHuman.h

@@ -0,0 +1,80 @@
+/*
+	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/>.
+*/
+/**
+ * Formatting functions for errors referencing positions and locations in the source.
+ */
+
+#pragma once
+
+#include <liblangutil/SourceReferenceExtractor.h>
+#include <liblangutil/SourceReferenceFormatter.h> // SourceReferenceFormatterBase
+
+#include <libdevcore/AnsiColorized.h>
+
+#include <ostream>
+#include <sstream>
+#include <functional>
+
+namespace dev
+{
+struct Exception; // forward
+}
+
+namespace langutil
+{
+
+struct SourceLocation;
+struct SourceReference;
+
+class SourceReferenceFormatterHuman: public SourceReferenceFormatter
+{
+public:
+	SourceReferenceFormatterHuman(std::ostream& _stream, bool colored):
+		SourceReferenceFormatter{_stream}, m_colored{colored}
+	{}
+
+	void printSourceLocation(SourceReference const& _ref) override;
+	void printExceptionInformation(SourceReferenceExtractor::Message const& _msg) override;
+	using SourceReferenceFormatter::printExceptionInformation;
+
+	static std::string formatExceptionInformation(
+		dev::Exception const& _exception,
+		std::string const& _name,
+		bool colored = false
+	)
+	{
+		std::ostringstream errorOutput;
+
+		SourceReferenceFormatterHuman formatter(errorOutput, colored);
+		formatter.printExceptionInformation(_exception, _name);
+		return errorOutput.str();
+	}
+
+private:
+	dev::AnsiColorized normalColored() const;
+	dev::AnsiColorized frameColored() const;
+	dev::AnsiColorized errorColored() const;
+	dev::AnsiColorized messageColored() const;
+	dev::AnsiColorized secondaryColored() const;
+	dev::AnsiColorized highlightColored() const;
+	dev::AnsiColorized diagColored() const;
+
+private:
+	bool m_colored;
+};
+
+}

solc/CommandLineInterface.cpp

@@ -35,6 +35,7 @@
 #include <libsolidity/interface/CompilerStack.h>
 #include <libsolidity/interface/StandardCompiler.h>
 #include <liblangutil/SourceReferenceFormatter.h>
+#include <liblangutil/SourceReferenceFormatterHuman.h>
 #include <libsolidity/interface/GasEstimator.h>
 #include <libsolidity/interface/AssemblyStack.h>
 
@@ -46,6 +47,8 @@
 #include <libdevcore/CommonIO.h>
 #include <libdevcore/JSON.h>
 
+#include <memory>
+
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/operations.hpp>
 #include <boost/algorithm/string.hpp>
@@ -134,6 +137,9 @@ static string const g_strStrictAssembly = "strict-assembly";
 static string const g_strPrettyJson = "pretty-json";
 static string const g_strVersion = "version";
 static string const g_strIgnoreMissingFiles = "ignore-missing";
+static string const g_strColor = "color";
+static string const g_strNoColor = "no-color";
+static string const g_strNewReporter = "new-reporter";
 
 static string const g_argAbi = g_strAbi;
 static string const g_argPrettyJson = g_strPrettyJson;
@@ -169,6 +175,9 @@ static string const g_argStrictAssembly = g_strStrictAssembly;
 static string const g_argVersion = g_strVersion;
 static string const g_stdinFileName = g_stdinFileNameStr;
 static string const g_argIgnoreMissingFiles = g_strIgnoreMissingFiles;
+static string const g_argColor = g_strColor;
+static string const g_argNoColor = g_strNoColor;
+static string const g_argNewReporter = g_strNewReporter;
 
 /// Possible arguments to for --combined-json
 static set<string> const g_combinedJsonArgs
@@ -652,6 +661,9 @@ Allowed options)",
 			po::value<string>()->value_name("path(s)"),
 			"Allow a given path for imports. A list of paths can be supplied by separating them with a comma."
 		)
+		(g_argColor.c_str(), "Force colored output.")
+		(g_argNoColor.c_str(), "Explicitly disable colored output, disabling terminal auto-detection.")
+		(g_argNewReporter.c_str(), "Enables new diagnostics reporter.")
 		(g_argIgnoreMissingFiles.c_str(), "Ignore missing files.");
 	po::options_description outputComponents("Output Components");
 	outputComponents.add_options()
@@ -691,6 +703,14 @@ Allowed options)",
 		return false;
 	}
 
+	if (m_args.count(g_argColor) && m_args.count(g_argNoColor))
+	{
+		serr() << "Option " << g_argColor << " and " << g_argNoColor << " are mutualy exclusive." << endl;
+		return false;
+	}
+
+	m_coloredOutput = !m_args.count(g_argNoColor) && (isatty(STDERR_FILENO) || m_args.count(g_argColor));
+
 	if (m_args.count(g_argHelp) || (isatty(fileno(stdin)) && _argc == 1))
 	{
 		sout() << desc;
@@ -858,7 +878,11 @@ bool CommandLineInterface::processInput()
 
 	m_compiler.reset(new CompilerStack(fileReader));
 
-	SourceReferenceFormatter formatter(serr(false));
+	unique_ptr<SourceReferenceFormatter> formatter;
+	if (m_args.count(g_argNewReporter))
+		formatter = make_unique<SourceReferenceFormatterHuman>(serr(false), m_coloredOutput);
+	else
+		formatter = make_unique<SourceReferenceFormatter>(serr(false));
 
 	try
 	{
@@ -881,7 +905,7 @@ bool CommandLineInterface::processInput()
 		for (auto const& error: m_compiler->errors())
 		{
 			g_hasOutput = true;
-			formatter.printExceptionInformation(
+			formatter->printExceptionInformation(
 				*error,
 				(error->type() == Error::Type::Warning) ? "Warning" : "Error"
 			);
@@ -893,7 +917,7 @@ bool CommandLineInterface::processInput()
 	catch (CompilerError const& _exception)
 	{
 		g_hasOutput = true;
-		formatter.printExceptionInformation(_exception, "Compiler error");
+		formatter->printExceptionInformation(_exception, "Compiler error");
 		return false;
 	}
 	catch (InternalCompilerError const& _exception)
@@ -915,7 +939,7 @@ bool CommandLineInterface::processInput()
 		else
 		{
 			g_hasOutput = true;
-			formatter.printExceptionInformation(_error, _error.typeName());
+			formatter->printExceptionInformation(_error, _error.typeName());
 		}
 
 		return false;
@@ -1221,12 +1245,16 @@ bool CommandLineInterface::assemble(
 	for (auto const& sourceAndStack: assemblyStacks)
 	{
 		auto const& stack = sourceAndStack.second;
-		SourceReferenceFormatter formatter(serr(false));
+		unique_ptr<SourceReferenceFormatter> formatter;
+		if (m_args.count(g_argNewReporter))
+			formatter = make_unique<SourceReferenceFormatterHuman>(serr(false), m_coloredOutput);
+		else
+			formatter = make_unique<SourceReferenceFormatter>(serr(false));
 
 		for (auto const& error: stack.errors())
 		{
 			g_hasOutput = true;
-			formatter.printExceptionInformation(
+			formatter->printExceptionInformation(
 				*error,
 				(error->type() == Error::Type::Warning) ? "Warning" : "Error"
 			);

solc/CommandLineInterface.h

@@ -109,6 +109,8 @@ class CommandLineInterface
 	std::unique_ptr<dev::solidity::CompilerStack> m_compiler;
 	/// EVM version to use
 	EVMVersion m_evmVersion;
+	/// Whether or not to colorize diagnostics output.
+	bool m_coloredOutput = true;
 };
 
 }