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

diff --git a/src/saf/saf_base.nit b/src/saf/saf_base.nit
index 806b711..fcc409e 100644
--- a/src/saf/saf_base.nit
+++ b/src/saf/saf_base.nit
@@ -56,6 +56,13 @@ abstract class StaticAnalysis
 	# implementation of this method is the responsability the subclass.
 	fun new_initial_flow: FLOW is abstract
 
+	# Initial flow set to use within methods.
+	#
+	# Returns `new_initial_flow` by default.
+	# Redefine this method to inject things in the inset like parameters from
+	# the signature.
+	fun new_initial_method_flow(v: AMethPropdef): FLOW do return new_initial_flow
+
 	# The merge operation on sets for confluence.
 	#
 	# Depends on the analysis performed.
@@ -131,3 +138,109 @@ redef class ANode
 		v.outsets[self] = v.current_outset
 	end
 end
+
+redef class AIfExpr
+
+	# Merge flow on if .. else constructs.
+	redef fun accept_forward_analysis(v) do
+		v.enter_visit(n_expr)
+		var inset = v.current_inset
+		var outset = v.current_outset
+
+		if n_then != null then v.enter_visit(n_then)
+		var then_outset = v.current_outset
+
+		v.current_inset = inset
+		v.current_outset = outset
+
+		if n_else != null then
+			v.enter_visit(n_else)
+			outset = v.merge(then_outset, v.current_outset)
+		else
+			outset = v.merge(then_outset, v.current_inset)
+		end
+		v.current_inset = inset
+		v.current_outset = outset
+	end
+end
+
+# Represent all kind of `do .. end` blocks.
+#
+# Used to factorize implementations across do blocks, whiles, fors and loops.
+#
+# This factorization makes sense since all these contructs can be flow managed
+# through contine and breack statements.
+#
+# TODO move this up in the module hierarchy
+interface ADoBlockHelper
+	# Lookup fix point for this loop.
+	fun loop_fix_point(v: StaticAnalysis, node: ANode) do
+		var inset = v.current_inset.clone
+		var last: nullable FlowSet = null
+		while v.current_outset != last do
+			v.enter_visit(node)
+			v.current_inset = v.merge(inset, v.current_outset)
+			v.current_outset = v.current_inset.clone
+			last = v.current_outset.clone
+		end
+		v.current_inset = inset
+		v.current_outset = v.merge(inset, v.current_outset)
+	end
+
+	# Factorize loop forward analysis.
+	fun accept_loop_forward_analysis(v: StaticAnalysis) do
+		var n_block = loop_block
+		if not n_block == null then loop_fix_point(v, n_block)
+	end
+
+	# The block contained by this loop.
+	fun loop_block: nullable ANode is abstract
+end
+
+redef class ADoExpr
+	super ADoBlockHelper
+
+	redef fun loop_block do return self.n_block
+	redef fun accept_forward_analysis(v) do accept_loop_forward_analysis(v)
+end
+
+redef class ALoopExpr
+	super ADoBlockHelper
+
+	redef fun loop_block do return self.n_block
+	redef fun accept_forward_analysis(v) do accept_loop_forward_analysis(v)
+end
+
+redef class AWhileExpr
+	super ADoBlockHelper
+
+	redef fun loop_block do return self.n_block
+
+	redef fun accept_forward_analysis(v) do
+		v.enter_visit(n_expr)
+		accept_loop_forward_analysis(v)
+	end
+end
+
+redef class AForExpr
+	super ADoBlockHelper
+
+	redef fun loop_block do return self.n_block
+
+	redef fun accept_forward_analysis(v) do
+		for n_group in n_groups do
+			v.enter_visit(n_group.n_expr)
+		end
+		accept_loop_forward_analysis(v)
+	end
+end
+
+redef class AMethPropdef
+	redef fun accept_forward_analysis(v) do
+		v.current_inset = v.new_initial_method_flow(self)
+		v.current_outset = v.current_inset.clone
+		v.insets[self] = v.current_inset
+		visit_all(v)
+		v.outsets[self] = v.current_outset
+	end
+end