core: refactor DotGraphVisitor

jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java

@@ -62,7 +62,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 	private List<BlockNode> exitBlocks;
 
 	private Region region;
-	private List<ExceptionHandler> exceptionHandlers;
+	private List<ExceptionHandler> exceptionHandlers = Collections.emptyList();
 	private List<LoopAttr> loops = Collections.emptyList();
 
 	public MethodNode(ClassNode classNode, Method mthData) {
@@ -134,9 +134,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 		}
 		blocks = null;
 		exitBlocks = null;
-		if (exceptionHandlers != null) {
-			exceptionHandlers.clear();
-		}
+		exceptionHandlers.clear();
 		noCode = true;
 	}
 
@@ -440,7 +438,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 	}
 
 	public ExceptionHandler addExceptionHandler(ExceptionHandler handler) {
-		if (exceptionHandlers == null) {
+		if (exceptionHandlers.isEmpty()) {
 			exceptionHandlers = new ArrayList<ExceptionHandler>(2);
 		} else {
 			for (ExceptionHandler h : exceptionHandlers) {
@@ -454,7 +452,7 @@ public class MethodNode extends LineAttrNode implements ILoadable {
 	}
 
 	public List<ExceptionHandler> getExceptionHandlers() {
-		return exceptionHandlers;
+		return Collections.unmodifiableList(exceptionHandlers);
 	}
 
 	/**

jadx-core/src/main/java/jadx/core/dex/visitors/DotGraphVisitor.java

@@ -3,6 +3,8 @@ package jadx.core.dex.visitors;
 import jadx.core.codegen.CodeWriter;
 import jadx.core.codegen.MethodGen;
 import jadx.core.dex.attributes.IAttributeNode;
+import jadx.core.dex.instructions.IfNode;
+import jadx.core.dex.instructions.InsnType;
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.IContainer;
 import jadx.core.dex.nodes.IRegion;
@@ -10,9 +12,13 @@ import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.trycatch.ExceptionHandler;
 import jadx.core.utils.InsnUtils;
+import jadx.core.utils.RegionUtils;
 import jadx.core.utils.Utils;
 
 import java.io.File;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 public class DotGraphVisitor extends AbstractVisitor {
 
@@ -23,6 +29,9 @@ public class DotGraphVisitor extends AbstractVisitor {
 	private final boolean useRegions;
 	private final boolean rawInsn;
 
+	private CodeWriter dot;
+	private CodeWriter conn;
+
 	public DotGraphVisitor(File outDir, boolean useRegions, boolean rawInsn) {
 		this.dir = outDir;
 		this.useRegions = useRegions;
@@ -38,45 +47,39 @@ public class DotGraphVisitor extends AbstractVisitor {
 		if (mth.isNoCode()) {
 			return;
 		}
-		CodeWriter dot = new CodeWriter();
-		CodeWriter conn = new CodeWriter();
+		dot = new CodeWriter();
+		conn = new CodeWriter();
 
-		dot.startLine("digraph \"CFG for"
-				+ escape(mth.getParentClass().getFullName() + "." + mth.getMethodInfo().getShortId())
-				+ "\" {");
+		dot.startLine("digraph \"CFG for");
+		dot.add(escape(mth.getParentClass().getFullName() + "." + mth.getMethodInfo().getShortId()));
+		dot.add("\" {");
 
 		if (useRegions) {
 			if (mth.getRegion() == null) {
 				return;
 			}
-
-			processRegion(mth, mth.getRegion(), dot, conn);
-			if (mth.getExceptionHandlers() != null) {
-				for (ExceptionHandler h : mth.getExceptionHandlers()) {
-					if (h.getHandlerRegion() != null) {
-						processRegion(mth, h.getHandlerRegion(), dot, conn);
-					}
-				}
-			}
+			processMethodRegion(mth);
 		} else {
 			for (BlockNode block : mth.getBasicBlocks()) {
-				processBlock(mth, block, dot, conn);
+				processBlock(mth, block);
 			}
 		}
 
-		String attrs = attributesString(mth);
-
-		dot.startLine("MethodNode[shape=record,label=\"{"
-				+ escape(mth.getAccessFlags().makeString())
-				+ escape(mth.getReturnType() + " "
+		dot.startLine("MethodNode[shape=record,label=\"{");
+		dot.add(escape(mth.getAccessFlags().makeString()));
+		dot.add(escape(mth.getReturnType() + " "
 				+ mth.getParentClass().getFullName() + "." + mth.getName()
-				+ "(" + Utils.listToString(mth.getArguments(true)) + ") ")
-				+ (attrs.length() == 0 ? "" : " | " + attrs)
-				+ "}\"];");
+				+ "(" + Utils.listToString(mth.getArguments(true)) + ") "));
 
-		dot.startLine("MethodNode -> " + makeName(mth.getEnterBlock()) + ";");
+		String attrs = attributesString(mth);
+		if (attrs.length() != 0) {
+			dot.add(" | ").add(attrs);
+		}
+		dot.add("}\"];");
 
-		dot.add(conn);
+		dot.startLine("MethodNode -> ").add(makeName(mth.getEnterBlock())).add(';');
+
+		dot.add(conn.toString());
 
 		dot.startLine('}');
 		dot.startLine();
@@ -88,27 +91,55 @@ public class DotGraphVisitor extends AbstractVisitor {
 		dot.save(dir, mth.getParentClass().getClassInfo().getFullPath() + "_graphs", fileName);
 	}
 
-	private void processRegion(MethodNode mth, IContainer region, CodeWriter dot, CodeWriter conn) {
+	private void processMethodRegion(MethodNode mth) {
+		processRegion(mth, mth.getRegion());
+		for (ExceptionHandler h : mth.getExceptionHandlers()) {
+			if (h.getHandlerRegion() != null) {
+				processRegion(mth, h.getHandlerRegion());
+			}
+		}
+		Set<BlockNode> regionsBlocks = new HashSet<BlockNode>(mth.getBasicBlocks().size());
+		RegionUtils.getAllRegionBlocks(mth.getRegion(), regionsBlocks);
+		for (ExceptionHandler handler : mth.getExceptionHandlers()) {
+			IContainer handlerRegion = handler.getHandlerRegion();
+			if (handlerRegion != null) {
+				RegionUtils.getAllRegionBlocks(handlerRegion, regionsBlocks);
+			}
+		}
+		for (BlockNode block : mth.getBasicBlocks()) {
+			if (!regionsBlocks.contains(block)) {
+				processBlock(mth, block, true);
+			}
+		}
+	}
+
+	private void processRegion(MethodNode mth, IContainer region) {
 		if (region instanceof IRegion) {
 			IRegion r = (IRegion) region;
-			String attrs = attributesString(r);
 			dot.startLine("subgraph " + makeName(region) + " {");
-			dot.startLine("label = \"" + r
-					+ (attrs.length() == 0 ? "" : " | " + attrs)
-					+ "\";");
+			dot.startLine("label = \"").add(r);
+			String attrs = attributesString(r);
+			if (attrs.length() != 0) {
+				dot.add(" | ").add(attrs);
+			}
+			dot.add("\";");
 			dot.startLine("node [shape=record,color=blue];");
 
 			for (IContainer c : r.getSubBlocks()) {
-				processRegion(mth, c, dot, conn);
+				processRegion(mth, c);
 			}
 
 			dot.startLine('}');
 		} else if (region instanceof BlockNode) {
-			processBlock(mth, (BlockNode) region, dot, conn);
+			processBlock(mth, (BlockNode) region);
 		}
 	}
 
-	private void processBlock(MethodNode mth, BlockNode block, CodeWriter dot, CodeWriter conn) {
+	private void processBlock(MethodNode mth, BlockNode block) {
+		processBlock(mth, block, false);
+	}
+
+	private void processBlock(MethodNode mth, BlockNode block, boolean error) {
 		String attrs = attributesString(block);
 		if (PRINT_REGISTERS_STATES) {
 			if (block.getStartState() != null) {
@@ -119,21 +150,34 @@ public class DotGraphVisitor extends AbstractVisitor {
 				attrs += escape("RE: " + block.getEndState()) + NL;
 			}
 		}
-
+		dot.startLine(makeName(block));
+		dot.add(" [shape=record,");
+		if (error) {
+			dot.add("color=red,");
+		}
+		dot.add("label=\"{");
+		dot.add(block.getId()).add("\\:\\ ");
+		dot.add(InsnUtils.formatOffset(block.getStartOffset()));
+		if (attrs.length() != 0) {
+			dot.add('|').add(attrs);
+		}
 		String insns = insertInsns(mth, block);
+		if (insns.length() != 0) {
+			dot.add('|').add(insns);
+		}
+		dot.add("}\"];");
 
-		dot.startLine(makeName(block) + " [shape=record,label=\"{"
-				+ block.getId() + "\\:\\ "
-				+ InsnUtils.formatOffset(block.getStartOffset())
-				+ (attrs.length() == 0 ? "" : "|" + attrs)
-				+ (insns.length() == 0 ? "" : "|" + insns)
-				+ "}\"];");
-
-		for (BlockNode next : block.getSuccessors()) {
-			conn.startLine(makeName(block) + " -> " + makeName(next) + ";");
+		BlockNode falsePath = null;
+		List<InsnNode> list = block.getInstructions();
+		if (!list.isEmpty() && list.get(0).getType() == InsnType.IF) {
+			falsePath = ((IfNode) list.get(0)).getElseBlock();
 		}
-		for (BlockNode next : block.getDominatesOn()) {
-			conn.startLine(makeName(block) + " -> " + makeName(next) + "[style=dotted];");
+		for (BlockNode next : block.getSuccessors()) {
+			conn.startLine(makeName(block)).add(" -> ").add(makeName(next));
+			if (next == falsePath) {
+				conn.add("[style=dotted]");
+			}
+			conn.add(';');
 		}
 	}
 

jadx-core/src/main/java/jadx/core/dex/visitors/regions/DepthRegionTraverser.java

@@ -24,10 +24,8 @@ public class DepthRegionTraverser {
 	public static void traverseAll(MethodNode mth, IRegionVisitor visitor) {
 		traverse(mth, visitor, mth.getRegion());
 
-		if (mth.getExceptionHandlers() != null) {
-			for (ExceptionHandler h : mth.getExceptionHandlers()) {
-				traverse(mth, visitor, h.getHandlerRegion());
-			}
+		for (ExceptionHandler h : mth.getExceptionHandlers()) {
+			traverse(mth, visitor, h.getHandlerRegion());
 		}
 	}
 }

jadx-core/src/main/java/jadx/core/dex/visitors/regions/ProcessTryCatchRegions.java

@@ -40,7 +40,7 @@ public class ProcessTryCatchRegions extends AbstractRegionVisitor {
 	private final Map<BlockNode, TryCatchBlock> tryBlocksMap = new HashMap<BlockNode, TryCatchBlock>(2);
 
 	public ProcessTryCatchRegions(MethodNode mth) {
-		if (mth.isNoCode() || mth.getExceptionHandlers() == null) {
+		if (mth.isNoCode() || mth.getExceptionHandlers().isEmpty()) {
 			return;
 		}
 

jadx-core/src/main/java/jadx/core/dex/visitors/regions/RegionMakerVisitor.java

@@ -37,7 +37,7 @@ public class RegionMakerVisitor extends AbstractVisitor {
 		// fill region structure
 		mth.setRegion(rm.makeRegion(mth.getEnterBlock(), state));
 
-		if (mth.getExceptionHandlers() != null) {
+		if (!mth.getExceptionHandlers().isEmpty()) {
 			state = new RegionStack(mth);
 			for (ExceptionHandler handler : mth.getExceptionHandlers()) {
 				rm.processExcHandler(handler, state);

jadx-core/src/main/java/jadx/core/utils/RegionUtils.java

@@ -11,6 +11,7 @@ import jadx.core.dex.trycatch.TryCatchBlock;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
 import java.util.List;
+import java.util.Set;
 
 public class RegionUtils {
 
@@ -47,7 +48,7 @@ public class RegionUtils {
 		}
 	}
 
-	public static void getAllRegionBlocks(IContainer container, List<BlockNode> blocks) {
+	public static void getAllRegionBlocks(IContainer container, Set<BlockNode> blocks) {
 		if (container instanceof BlockNode) {
 			blocks.add((BlockNode) container);
 		} else if (container instanceof IRegion) {
@@ -108,7 +109,8 @@ public class RegionUtils {
 	}
 
 	/**
-	 * Check if {@code region} contains in {@code container}.<br>
+	 * Check if {@code region} contains in {@code container}.
+	 * <br>
 	 * For simple region (not from exception handlers) search in parents
 	 * otherwise run recursive search because exception handlers can have several parents
 	 */
@@ -124,9 +126,8 @@ public class RegionUtils {
 			if (parent == null) {
 				if (region.getAttributes().contains(AttributeType.EXC_HANDLER)) {
 					return isRegionContainsExcHandlerRegion(container, region);
-				} else {
-					return false;
 				}
+				return false;
 			}
 			region = parent;
 			parent = region.getParent();