metrics: `--nullables` distinguishes safe and unsafe calls on `null`

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/metrics/nullables_metrics.nit b/src/metrics/nullables_metrics.nit
index 7f1b898..2c96462 100644 (file)
--- a/src/metrics/nullables_metrics.nit
+++ b/src/metrics/nullables_metrics.nit
@@ -109,6 +109,7 @@ private class NullableSends
 
        var total_sends: Int = 0
        var nullable_sends: Int = 0
+       var nullable_eq_sends: Int = 0
        var buggy_sends: Int = 0
 
        # Get a new visitor on a classef to add type count in `typecount`.
@@ -130,7 +131,12 @@ private class NullableSends
                        end
                        t = t.anchor_to(self.nclassdef.mclassdef.mmodule, self.nclassdef.mclassdef.bound_mtype)
                        if t isa MNullableType then
-                               self.nullable_sends += 1
+                               var name = n.callsite.mproperty.name
+                               if name == "==" or name == "!=" or name == "is_same_instance" then
+                                       self.nullable_eq_sends += 1
+                               else
+                                       self.nullable_sends += 1
+                               end
                        else if t isa MClassType then
                                # Nothing
                        else
@@ -146,6 +152,7 @@ do
        print "--- Sends on Nullable Receiver ---"
        var total_sends = 0
        var nullable_sends = 0
+       var nullable_eq_sends = 0
        var buggy_sends = 0
 
        # Visit all the source code to collect data
@@ -155,10 +162,12 @@ do
                        visitor.enter_visit(nclassdef)
                        total_sends += visitor.total_sends
                        nullable_sends += visitor.nullable_sends
+                       nullable_eq_sends += visitor.nullable_eq_sends
                        buggy_sends += visitor.buggy_sends
                end
        end
        print "Total number of sends: {total_sends}"
-       print "Number of sends on a nullable receiver: {nullable_sends} ({div(nullable_sends*100,total_sends)}%)"
+       print "Number of sends on a unsafe nullable receiver: {nullable_sends} ({div(nullable_sends*100,total_sends)}%)"
+       print "Number of sends on a safe nullable receiver: {nullable_eq_sends} ({div(nullable_eq_sends*100,total_sends)}%)"
        print "Number of buggy sends (cannot determine the type of the receiver): {buggy_sends} ({div(buggy_sends*100,total_sends)}%)"
 end