[eva] fix pretty-printing of dot graph in traces domain

Without escaping strings such as variable names, the produced .dot file
might print '\result' as a variable name, which results in '\r' being
stripped. Dot will then show edges such as 'esult<main>'.

src/plugins/eva/domains/traces_domain.ml

@@ -817,7 +817,9 @@ module GraphDot = OCamlGraph.Graphviz.Dot(struct
     let edge_attributes : E.t -> OCamlGraph.Graphviz.DotAttributes.edge list =
       function
       | Usual(_,{edge_trans = Loop _},_) -> [`Label (Format.asprintf "leave_loop")]
-      | Usual(_,e,_) -> [`Label (Format.asprintf "@[<h>%a@]" Transition.pretty e.edge_trans)]
+      | Usual(_,e,_) ->
+        [`Label (Format.asprintf "@[<h>%a@]"
+                   (Pretty_utils.pp_escaped Transition.pretty) e.edge_trans)]
       | Head _ -> []
       | Back(_,_,_) -> [`Constraint false]
   end)

tests/value/traces/oracle/test1.dot

@@ -51,55 +51,53 @@ digraph G {
   
   
   n0S -> n1S [label="initialize variable: entropy_source", ];
-  n1S -> n2S [label="initialize global variable using type
-entropy_source", ];
+  n1S -> n2S [label="initialize global variable using type\nentropy_source", ];
   n2S -> n3S [label="initialize variable: g", ];
-  n3S -> n4S [label="Assign: g = 42", ];
-  n4S -> n5S [label="initialize formal variable using type
-c", ];
-  n5S -> n6S [label="EnterScope: tmp", ];
-  n6S -> n7S [label="Assign: tmp = 0", ];
-  n7S -> n8S [label="Assume: c true", ];
-  n7S -> n10S [label="Assume: c false", ];
-  n8S -> n9S [label="Assign: tmp = g", ];
-  n9S -> n12S [label="EnterScope: i", ];
-  n10S -> n11S [label="Assign: tmp = 2", ];
-  n11S -> n13S [label="EnterScope: i", ];
+  n3S -> n4S [label="Assign:\ng = 42", ];
+  n4S -> n5S [label="initialize formal variable using type\nc", ];
+  n5S -> n6S [label="EnterScope:\ntmp", ];
+  n6S -> n7S [label="Assign:\ntmp = 0", ];
+  n7S -> n8S [label="Assume:\nc true", ];
+  n7S -> n10S [label="Assume:\nc false", ];
+  n8S -> n9S [label="Assign:\ntmp = g", ];
+  n9S -> n12S [label="EnterScope:\ni", ];
+  n10S -> n11S [label="Assign:\ntmp = 2", ];
+  n11S -> n13S [label="EnterScope:\ni", ];
   n12S -> n14S [label="initialize variable: i", ];
   n13S -> n16S [label="initialize variable: i", ];
-  n14S -> n15S [label="Assign: i = 0", ];
+  n14S -> n15S [label="Assign:\ni = 0", ];
   n15S -> n19S [label="enter_loop", ];
-  n16S -> n17S [label="Assign: i = 0", ];
+  n16S -> n17S [label="Assign:\ni = 0", ];
   n17S -> n18S [label="enter_loop", ];
-  n18S -> n20S [label="Assume: i < 3 true", ];
-  n19S -> n21S [label="Assume: i < 3 true", ];
-  n20S -> n22S [label="Assign: tmp = tmp + 1", ];
-  n21S -> n23S [label="Assign: tmp = tmp + 1", ];
-  n22S -> n24S [label="Assign: i = i + 1", ];
-  n23S -> n25S [label="Assign: i = i + 1", ];
-  n24S -> n27S [label="Assume: i < 3 true", ];
-  n25S -> n26S [label="Assume: i < 3 true", ];
-  n26S -> n28S [label="Assign: tmp = tmp + 1", ];
-  n27S -> n29S [label="Assign: tmp = tmp + 1", ];
-  n28S -> n30S [label="Assign: i = i + 1", ];
-  n29S -> n31S [label="Assign: i = i + 1", ];
-  n30S -> n33S [label="Assume: i < 3 true", ];
-  n31S -> n32S [label="Assume: i < 3 true", ];
-  n32S -> n34S [label="Assign: tmp = tmp + 1", ];
-  n33S -> n35S [label="Assign: tmp = tmp + 1", ];
-  n34S -> n36S [label="Assign: i = i + 1", ];
-  n35S -> n37S [label="Assign: i = i + 1", ];
-  n36S -> n39S [label="Assume: i < 3 false", ];
-  n37S -> n38S [label="Assume: i < 3 false", ];
-  n38S -> n41S [label="LeaveScope: i", ];
-  n39S -> n40S [label="LeaveScope: i", ];
-  n40S -> n42S [label="Assign: g = tmp", ];
-  n41S -> n43S [label="Assign: g = tmp", ];
-  n42S -> n44S [label="EnterScope: \result<main>", ];
-  n43S -> n46S [label="EnterScope: \result<main>", ];
-  n44S -> n45S [label="Assign: \result<main> = tmp", ];
+  n18S -> n20S [label="Assume:\ni < 3 true", ];
+  n19S -> n21S [label="Assume:\ni < 3 true", ];
+  n20S -> n22S [label="Assign:\ntmp = tmp + 1", ];
+  n21S -> n23S [label="Assign:\ntmp = tmp + 1", ];
+  n22S -> n24S [label="Assign:\ni = i + 1", ];
+  n23S -> n25S [label="Assign:\ni = i + 1", ];
+  n24S -> n27S [label="Assume:\ni < 3 true", ];
+  n25S -> n26S [label="Assume:\ni < 3 true", ];
+  n26S -> n28S [label="Assign:\ntmp = tmp + 1", ];
+  n27S -> n29S [label="Assign:\ntmp = tmp + 1", ];
+  n28S -> n30S [label="Assign:\ni = i + 1", ];
+  n29S -> n31S [label="Assign:\ni = i + 1", ];
+  n30S -> n33S [label="Assume:\ni < 3 true", ];
+  n31S -> n32S [label="Assume:\ni < 3 true", ];
+  n32S -> n34S [label="Assign:\ntmp = tmp + 1", ];
+  n33S -> n35S [label="Assign:\ntmp = tmp + 1", ];
+  n34S -> n36S [label="Assign:\ni = i + 1", ];
+  n35S -> n37S [label="Assign:\ni = i + 1", ];
+  n36S -> n39S [label="Assume:\ni < 3 false", ];
+  n37S -> n38S [label="Assume:\ni < 3 false", ];
+  n38S -> n41S [label="LeaveScope:\ni", ];
+  n39S -> n40S [label="LeaveScope:\ni", ];
+  n40S -> n42S [label="Assign:\ng = tmp", ];
+  n41S -> n43S [label="Assign:\ng = tmp", ];
+  n42S -> n44S [label="EnterScope:\n\\result<main>", ];
+  n43S -> n46S [label="EnterScope:\n\\result<main>", ];
+  n44S -> n45S [label="Assign:\n\\result<main> = tmp", ];
   n45S -> n48S [label="join", ];
-  n46S -> n47S [label="Assign: \result<main> = tmp", ];
+  n46S -> n47S [label="Assign:\n\\result<main> = tmp", ];
   n47S -> n48S [label="join", ];
   
   }