Show bytecode coverage in CallTargetBrowser

Since bytecode nodes are lazily inserted into Truffle AST, we can use this information to find out whether a bytecode has been executed or not. This displays this information in the bytecode view of the CallTargetBrowser. Red means not covered, green means covered, gray means unknown (closures are currently not supported).

src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/selectedBytecodes.st

@@ -0,0 +1,21 @@
+message list
+selectedBytecodes
+	| cm text |
+	cm := (self selectedClassOrMetaClass compiledMethodAt: self selectedMessageName
+			ifAbsent: [ ^ '' asText ]).
+	text := cm symbolic asText.
+	text addAttribute: TextColor gray; yourself.
+	cm callTarget ifNotNil: [ :ct | | nodes index string |
+		nodes := ct getRootNode executeBytecodeNode bytecodeNodes.
+		index := 1.
+		string := text string.
+		string lineIndicesDo: [ :start :end :endWithLineEnding |
+			(string at: start) = Character tab ifFalse: [ | numBytesOfBytecode |
+				text addAttribute: (TextColor color: (
+						(nodes at: index)
+							ifNil: [ Color red ] ifNotNil: [ Color green ]) muchDarker)
+					from: start to: end.
+				numBytesOfBytecode := ((string indexOf: $> startingAt: start) -
+											(string indexOf: $< startingAt: start)) // 3.
+				index := index + numBytesOfBytecode ]]].
+	^ text

src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/methodProperties.json

@@ -15,6 +15,7 @@
 		"inspectCallTarget" : "fn 2/17/2021 14:50",
 		"mainMessageListMenu:" : "fn 2/17/2021 14:51",
 		"messageList" : "fn 7/8/2021 12:02",
+		"selectedBytecodes" : "fn 7/14/2021 21:28",
 		"selectedMessage" : "fn 2/17/2021 12:26",
 		"showCallTargetInfo:" : "fn 2/17/2021 12:28",
 		"showingCallTargetInfo" : "fn 2/17/2021 12:01",