Fix running tests from any drive

libsolidity/interface/FileReader.cpp

@@ -276,14 +276,8 @@ boost::filesystem::path FileReader::normalizeCLIPathForVFS(
 	// If the path is on the same drive as the working dir, for portability we prefer not to
 	// include the root name. Do this only for non-UNC paths - my experiments show that on Windows
 	// when the working dir is an UNC path, / does not not actually refer to the root of the UNC path.
-	boost::filesystem::path normalizedRootPath = normalizedPath.root_path();
-	if (!isUNCPath(normalizedPath))
-	{
-		boost::filesystem::path workingDirRootPath = canonicalWorkDir.root_path();
-		// Ignore drive letter case on Windows (C:\ <=> c:\).
-		if (boost::filesystem::equivalent(normalizedRootPath, workingDirRootPath))
-			normalizedRootPath = "/";
-	}
+
+	boost::filesystem::path normalizedRootPath = normalizeCLIRootPathForVFS(normalizedPath, canonicalWorkDir);
 
 	// lexically_normal() will not squash paths like "/../../" into "/". We have to do it manually.
 	boost::filesystem::path dotDotPrefix = absoluteDotDotPrefix(normalizedPath);
@@ -308,6 +302,27 @@ boost::filesystem::path FileReader::normalizeCLIPathForVFS(
 	return normalizedPathNoDotDot;
 }
 
+boost::filesystem::path FileReader::normalizeCLIRootPathForVFS(
+	boost::filesystem::path const& _path,
+	boost::filesystem::path const& _workDir
+)
+{
+	solAssert(_workDir.is_absolute(), "");
+
+	boost::filesystem::path absolutePath = boost::filesystem::absolute(_path, _workDir);
+	boost::filesystem::path rootPath = absolutePath.root_path();
+	boost::filesystem::path baseRootPath = _workDir.root_path();
+
+	if (isUNCPath(absolutePath))
+		return rootPath;
+
+	// Ignore drive letter case on Windows (C:\ <=> c:\).
+	if (boost::filesystem::equivalent(rootPath, baseRootPath))
+		return "/";
+
+	return rootPath;
+}
+
 bool FileReader::isPathPrefix(boost::filesystem::path const& _prefix, boost::filesystem::path const& _path)
 {
 	solAssert(!_prefix.empty() && !_path.empty(), "");

libsolidity/interface/FileReader.h

@@ -115,6 +115,17 @@ public:
 		SymlinkResolution _symlinkResolution = SymlinkResolution::Disabled
 	);
 
+	/// Normalizes a root path by excluding, in some cases, its root name.
+	/// The function is used for better portability, and intended to omit root name
+	/// if the path can be used without it.
+	/// @param _path Path to normalize the root path.
+	/// @param _workDir Current working directory path, must be absolute.
+	/// @returns a normalized root path.
+	static boost::filesystem::path normalizeCLIRootPathForVFS(
+		boost::filesystem::path const& _path,
+		boost::filesystem::path const& _workDir = boost::filesystem::current_path()
+	);
+
 	/// @returns true if all the path components of @a _prefix are present at the beginning of @a _path.
 	/// Both paths must be absolute (or have slash as root) and normalized (no . or .. segments, no
 	/// multiple consecutive slashes).