X-Git-Url: http://nitlanguage.org

diff --git a/src/toolcontext.nit b/src/toolcontext.nit
index 6cc8889..5b9d020 100644
--- a/src/toolcontext.nit
+++ b/src/toolcontext.nit
@@ -90,9 +90,9 @@ class ToolContext
 
 			for m in messages do
 				if opt_no_color.value then
-					stderr.write("{m}\n")
+					sys.stderr.write("{m}\n")
 				else
-					stderr.write("{m.to_color_string}\n")
+					sys.stderr.write("{m.to_color_string}\n")
 				end
 			end
 
@@ -134,6 +134,33 @@ class ToolContext
 		end
 	end
 
+	# Executes a program while checking if it's available and if the execution ended correctly
+	#
+	# Stops execution and prints errors if the program isn't available or didn't end correctly
+	fun exec_and_check(args: Array[String], error: String)
+        do
+                var prog = args.first
+                args.remove_at 0
+
+                # Is the wanted program available?
+                var proc_which = new IProcess.from_a("which", [prog])
+                proc_which.wait
+                var res = proc_which.status
+                if res != 0 then
+                        print "{error}: executable \"{prog}\" not found"
+                        exit 1
+                end
+
+                # Execute the wanted program
+                var proc = new Process.from_a(prog, args)
+                proc.wait
+                res = proc.status
+                if res != 0 then
+                        print "{error}: execution of \"{prog} {args.join(" ")}\" failed"
+                        exit 1
+                end
+        end
+
 	# Global OptionContext
 	var option_context: OptionContext = new OptionContext
 
@@ -180,6 +207,13 @@ class ToolContext
 	# eg. `"Usage: tool [OPTION]... [FILE]...\nDo some things."`
 	var tooldescription: String writable = "Usage: [OPTION]... [ARG]..."
 
+	# Does `process_options` should accept an empty sequence of arguments.
+	# ie. nothing except options.
+	# Is `false` by default.
+	#
+	# If required, if should be set by the client before calling `process_options`
+	var accept_no_arguments writable = false
+
 	# print the full usage of the tool.
 	# Is called by `process_option` on `--help`.
 	# It also could be called by the client.
@@ -190,7 +224,7 @@ class ToolContext
 	end
 
 	# Parse and process the options given on the command line
-	fun process_options
+	fun process_options(args: Sequence[String])
 	do
 		self.opt_warn.value = 1
 
@@ -215,6 +249,12 @@ class ToolContext
 			exit 1
 		end
 
+		if option_context.rest.is_empty and not accept_no_arguments then
+			print tooldescription
+			print "Use --help for help"
+			exit 1
+		end
+
 		# Set verbose level
 		verbose_level = opt_verbose.value
 
@@ -225,5 +265,31 @@ class ToolContext
 			# Make sure the output directory exists
 			log_directory.mkdir
 		end
+
+		nit_dir = compute_nit_dir
+	end
+
+	# The identified root directory of the Nit project
+	var nit_dir: nullable String
+
+	private fun compute_nit_dir: nullable String
+	do
+		# a environ variable has precedence
+		var res = "NIT_DIR".environ
+		if not res.is_empty then return res
+
+		# find the runpath of the program from argv[0]
+		res = "{sys.program_name.dirname}/.."
+		if res.file_exists and "{res}/src/nit.nit".file_exists then return res.simplify_path
+
+		# find the runpath of the process from /proc
+		var exe = "/proc/self/exe"
+		if exe.file_exists then
+			res = exe.realpath
+			res = res.dirname.join_path("..")
+			if res.file_exists and "{res}/src/nit.nit".file_exists then return res.simplify_path
+		end
+
+		return null
 	end
 end