Implemented recipe files for dub dlang#2684

Author: MrcSnm

source/dub/commandline.d

@@ -534,7 +534,7 @@ struct CommonOptions {
 	bool verbose, vverbose, quiet, vquiet, verror, version_;
 	bool help, annotate, bare;
 	string[] registry_urls;
-	string root_path;
+	string root_path, recipeFile;
 	enum Color { automatic, on, off }
 	Color colorMode = Color.automatic;
 	SkipPackageSuppliers skipRegistry = SkipPackageSuppliers.none;
@@ -568,6 +568,7 @@ struct CommonOptions {
 	{
 		args.getopt("h|help", &help, ["Display general or command specific help"]);
 		args.getopt("root", &root_path, ["Path to operate in instead of the current working dir"]);
+		args.getopt("recipe", &recipeFile, ["Make dub use custom path as its recipe file"]);
 		args.getopt("registry", &registry_urls, [
 			"Search the given registry URL first when resolving dependencies. Can be specified multiple times. Available registry types:",
 			"  DUB: URL to DUB registry (default)",
@@ -812,7 +813,7 @@ class Command {
 		Dub dub;
 
 		if (options.bare) {
-			dub = new Dub(NativePath(options.root_path), getWorkingDirectory());
+			dub = new Dub(NativePath(options.root_path), getWorkingDirectory(), NativePath(options.recipeFile));
 			dub.defaultPlacementLocation = options.placementLocation;
 
 			return dub;
@@ -839,7 +840,7 @@ class Command {
 
 		// make the CWD package available so that for example sub packages can reference their
 		// parent package.
-		try dub.packageManager.getOrLoadPackage(NativePath(options.root_path), NativePath.init, false, StrictMode.Warn);
+		try dub.packageManager.getOrLoadPackage(NativePath(options.root_path), NativePath(options.recipeFile), false, StrictMode.Warn);
 		catch (Exception e) { logDiagnostic("No valid package found in current working directory: %s", e.msg); }
 
 		return dub;
@@ -1168,6 +1169,7 @@ abstract class PackageBuildCommand : Command {
 			return true;
 		}
 
+
 		bool from_cwd = package_name.length == 0 || package_name.startsWith(":");
 		// load package in root_path to enable searching for sub packages
 		if (loadCwdPackage(dub, from_cwd)) {
@@ -2430,7 +2432,7 @@ class DustmiteCommand : PackageBuildCommand {
 	{
 		if (!m_testPackage.length)
 			return super.prepareDub(options);
-		return new Dub(NativePath(options.root_path), getWorkingDirectory());
+		return new Dub(NativePath(options.root_path), getWorkingDirectory(), NativePath(options.recipeFile));
 	}
 
 	override int execute(Dub dub, string[] free_args, string[] app_args)

source/dub/dub.d

@@ -125,7 +125,7 @@ class Dub {
 		bool m_dryRun = false;
 		PackageManager m_packageManager;
 		PackageSupplier[] m_packageSuppliers;
-		NativePath m_rootPath;
+		NativePath m_rootPath, m_recipeFile;
 		SpecialDirs m_dirs;
 		Settings m_config;
 		Project m_project;
@@ -191,20 +191,22 @@ class Dub {
 		  pkg_root = The root of the location where packages are located
 					 Only packages under this location will be accessible.
 					 Note that packages at the top levels will be ignored.
+		  recipeFile = A file containing a dub build recipe
 	*/
-	this(NativePath root, NativePath pkg_root)
+	this(NativePath root, NativePath pkg_root, NativePath recipeFile)
 	{
 		// Note: We're doing `init()` before setting the `rootPath`,
 		// to prevent `init` from reading the project's settings.
 		init();
 		this.m_rootPath = root;
+		this.m_recipeFile = recipeFile;
 		m_packageManager = new PackageManager(pkg_root);
 	}
 
 	deprecated("Use the overload that takes `(NativePath pkg_root, NativePath root)`")
 	this(NativePath pkg_root)
 	{
-		this(pkg_root, pkg_root);
+		this(pkg_root, pkg_root, pkg_root);
 	}
 
 	private void init()
@@ -440,7 +442,7 @@ class Dub {
 	*/
 	void loadPackage()
 	{
-		loadPackage(m_rootPath);
+		loadPackage(!m_recipeFile.empty ? m_recipeFile : m_rootPath);
 	}
 
 	/// Loads the package from the specified path as the main project package.