Mark block reference variables (#74)

* Stack block fixes.

* Ghidra version fixes.

* Remove too-soon API changes.

* Move Flag type inside BlockLayout

* Move flag class closer to flags, don't use getter for flags.

* Remove unused variable.

* Add block reference variable markup action.

* Add null checks.

* Add error check for getting bytes in memory.

* Improve block reference variable markup.

* Add names to byref2 and byref3 structure components.

* Make block reference variable action check more robust.

Author: nmggithub

src/main/java/lol/fairplay/ghidraapple/actions/markasblock/MarkAsBlockByRefAction.kt

@@ -0,0 +1,33 @@
+package lol.fairplay.ghidraapple.actions.markasblock
+
+import docking.ActionContext
+import docking.action.MenuData
+import ghidra.app.context.ProgramLocationActionContext
+import ghidra.app.context.ProgramLocationContextAction
+import ghidra.app.decompiler.ClangVariableToken
+import ghidra.app.plugin.core.decompile.DecompilerActionContext
+import ghidra.framework.plugintool.PluginTool
+import lol.fairplay.ghidraapple.GhidraApplePluginPackage
+
+class MarkAsBlockByRefAction(
+    owner: String,
+    val plugin: PluginTool,
+) : ProgramLocationContextAction(
+        "Mark As Objective-C Block Reference Variable",
+        owner,
+    ) {
+    init {
+        popupMenuData = MenuData(arrayOf(this.name), GhidraApplePluginPackage.PKG_NAME)
+    }
+
+    override fun actionPerformed(context: ProgramLocationActionContext) {
+        plugin.executeBackgroundCommand(MarkBlockByRef(context.program, context.address), context.program)
+    }
+
+    override fun isEnabledForContext(context: ActionContext?): Boolean {
+        val typedContext =
+            context as? DecompilerActionContext ?: return false
+
+        return typedContext.tokenAtCursor is ClangVariableToken // TODO: Make this check more robust.
+    }
+}

src/main/java/lol/fairplay/ghidraapple/actions/markasblock/MarkAsGlobalBlockAction.kt

@@ -29,8 +29,13 @@ class MarkAsGlobalBlockAction(
         if (dataAtLocation.dataType.isBlockLayoutType) return false
 
         val pointerBytes = ByteArray(typedContext.program.defaultPointerSize)
-        val bytesRead = typedContext.program.memory.getBytes(typedContext.address, pointerBytes)
-        if (bytesRead != pointerBytes.size) return false
+        try {
+            val bytesRead =
+                typedContext.program.memory.getBytes(typedContext.address, pointerBytes)
+            if (bytesRead != pointerBytes.size) return false
+        } catch (_: Throwable) {
+            return false
+        }
 
         // If the pointer isn't to the global block symbol, it's not a global block.
         typedContext.program.symbolTable

src/main/java/lol/fairplay/ghidraapple/actions/markasblock/MarkAsStackBlockAction.kt

@@ -4,8 +4,11 @@ import docking.ActionContext
 import docking.action.MenuData
 import ghidra.app.context.ProgramLocationActionContext
 import ghidra.app.context.ProgramLocationContextAction
+import ghidra.app.decompiler.ClangStatement
+import ghidra.app.plugin.core.decompile.DecompilerActionContext
 import ghidra.framework.plugintool.PluginTool
 import lol.fairplay.ghidraapple.GhidraApplePluginPackage
+import lol.fairplay.ghidraapple.analysis.objectivec.blocks.doesPCodeOpPutStackBlockPointerOnStack
 import lol.fairplay.ghidraapple.analysis.objectivec.blocks.doesReferenceStackBlockSymbol
 import lol.fairplay.ghidraapple.analysis.objectivec.blocks.isBlockLayout
 
@@ -31,6 +34,15 @@ class MarkAsStackBlockAction(
         // If this is already a block layout, don't allow it to be marked again.
         if (typedContext.location.isBlockLayout) return false
 
+        if (typedContext is DecompilerActionContext) {
+            val parent = typedContext.tokenAtCursor.Parent()
+            if (parent is ClangStatement) {
+                val op = parent.pcodeOp
+                return doesPCodeOpPutStackBlockPointerOnStack(op, typedContext.program)
+            }
+            return false
+        }
+
         return typedContext.program.listing
             .getInstructionAt(typedContext.address)
             ?.doesReferenceStackBlockSymbol ?: return false