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

diff --git a/src/phase.nit b/src/phase.nit
index 6e96e96..ace2cb9 100644
--- a/src/phase.nit
+++ b/src/phase.nit
@@ -27,6 +27,43 @@ redef class ToolContext
 	# it is often simpler to use the constructor in `Phase`
 	var phases = new POSet[Phase]
 
+	# --disable-phase
+	var opt_disable_phase = new OptionArray("DEBUG: Disable a specific phase; use `list` to get the list.", "--disable-phase")
+
+	redef init
+	do
+		super
+
+		option_context.add_option(opt_disable_phase)
+	end
+
+	redef fun process_options(args)
+	do
+		super
+
+		for v in opt_disable_phase.value do
+			if v == "list" then
+				for p in phases_list do
+					var deps = p.in_hierarchy.direct_greaters
+					if deps.is_empty then
+						print p
+					else
+						print "{p} (dep: {deps.join(", ")})"
+					end
+				end
+				exit 0
+			end
+
+			var found = false
+			for p in phases do
+				if v != p.to_s then continue
+				found = true
+				p.disabled = true
+			end
+			if not found then fatal_error(null, "Error: no phase named `{v}`. Use `list` to list all phases.")
+		end
+	end
+
 	fun phases_list: Sequence[Phase]
 	do
 		var phases = self.phases.to_a
@@ -50,6 +87,7 @@ redef class ToolContext
 		for nmodule in nmodules do
 			self.info("Semantic analysis module {nmodule.location.file.filename}", 2)
 			for phase in phases do
+				if phase.disabled then continue
 				self.info(" phase: {phase}", 3)
 				assert phase.toolcontext == self
 				var errcount = self.error_count
@@ -125,6 +163,10 @@ abstract class Phase
 	# By default, the name is the lowercased prefix of the classname
 	redef fun to_s do return class_name.strip_extension("Phase").to_lower
 
+	# Is the phase globally disabled?
+	# A disabled phase is not called automatically called by `ToolContext::run_phases` and cie.
+	var disabled = false
+
 	# Specific actions to execute on the whole tree of a module
 	# @toimplement
 	fun process_nmodule(nmodule: AModule) do end