From 86003b45ca7a2132286c6f982a23f9c425f11b27 Mon Sep 17 00:00:00 2001
From: Alexey Andreev <konsoletyper@gmail.com>
Date: Sun, 24 Aug 2014 17:37:57 +0400
Subject: [PATCH] Fixes generation of CFG debug information

---
 .../main/java/org/teavm/model/BasicBlock.java |  4 +--
 .../model/util/LocationGraphBuilder.java      |  2 +-
 .../java/org/teavm/parsing/ProgramParser.java | 33 +++++++++----------
 3 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/teavm-core/src/main/java/org/teavm/model/BasicBlock.java b/teavm-core/src/main/java/org/teavm/model/BasicBlock.java
index 1ada9dc84..066df2651 100644
--- a/teavm-core/src/main/java/org/teavm/model/BasicBlock.java
+++ b/teavm-core/src/main/java/org/teavm/model/BasicBlock.java
@@ -173,9 +173,7 @@ public class BasicBlock implements BasicBlockReader {
     @Override
     public void readInstruction(int index, InstructionReader reader) {
         Instruction insn = instructions.get(index);
-        if (insn.getLocation() != null) {
-            reader.location(insn.getLocation());
-        }
+        reader.location(insn.getLocation());
         insn.acceptVisitor(new InstructionReadVisitor(reader));
     }
 
diff --git a/teavm-core/src/main/java/org/teavm/model/util/LocationGraphBuilder.java b/teavm-core/src/main/java/org/teavm/model/util/LocationGraphBuilder.java
index 96341b79d..1339dd985 100644
--- a/teavm-core/src/main/java/org/teavm/model/util/LocationGraphBuilder.java
+++ b/teavm-core/src/main/java/org/teavm/model/util/LocationGraphBuilder.java
@@ -66,7 +66,7 @@ class LocationGraphBuilder {
             for (Instruction insn : block.getInstructions()) {
                 if (insn.getLocation() != null) {
                     if (!started) {
-                        step.startLocations.add(location);
+                        step.startLocations.add(insn.getLocation());
                     }
                     started = true;
                     if (blockLocations[step.block] == null) {
diff --git a/teavm-core/src/main/java/org/teavm/parsing/ProgramParser.java b/teavm-core/src/main/java/org/teavm/parsing/ProgramParser.java
index 556046c9e..cf8a534f5 100644
--- a/teavm-core/src/main/java/org/teavm/parsing/ProgramParser.java
+++ b/teavm-core/src/main/java/org/teavm/parsing/ProgramParser.java
@@ -45,9 +45,6 @@ public class ProgramParser implements VariableDebugInformation {
     private int minLocal;
     private Program program;
     private String currentClassName;
-    private int currentLineNumber;
-    private boolean lineNumberChanged;
-    private InstructionLocation lastInsnLocation;
     private Map<Integer, List<LocalVariableNode>> localVariableMap = new HashMap<>();
     private Map<Instruction, Map<Integer, String>> variableDebugNames = new HashMap<>();
 
@@ -88,8 +85,6 @@ public class ProgramParser implements VariableDebugInformation {
     }
 
     public Program parse(MethodNode method, String className) {
-        currentLineNumber = -1;
-        lineNumberChanged = true;
         program = new Program();
         this.currentClassName = className;
         InsnList instructions = method.instructions;
@@ -103,7 +98,7 @@ public class ProgramParser implements VariableDebugInformation {
         insn.setTarget(program.basicBlockAt(1));
         program.basicBlockAt(0).getInstructions().add(insn);
         doAnalyze(method);
-        assemble();
+        assemble(method);
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             BasicBlock block = program.basicBlockAt(i);
             for (int j = 0; j < block.getTryCatchBlocks().size(); ++j) {
@@ -266,9 +261,11 @@ public class ProgramParser implements VariableDebugInformation {
         }
     }
 
-    private void assemble() {
+    private void assemble(MethodNode methodNode) {
         BasicBlock basicBlock = null;
         Map<Integer, String> accumulatedDebugNames = new HashMap<>();
+        Integer lastLineNumber = null;
+        InstructionLocation lastLocation = null;
         for (int i = 0; i < basicBlocks.size(); ++i) {
             BasicBlock newBasicBlock = basicBlocks.get(i);
             if (newBasicBlock != null) {
@@ -296,7 +293,19 @@ public class ProgramParser implements VariableDebugInformation {
                 }
                 accumulatedDebugNames.putAll(debugNames);
             }
+            AbstractInsnNode insnNode = methodNode.instructions.get(i);
+            if (insnNode instanceof LabelNode) {
+                Label label = ((LabelNode)insnNode).getLabel();
+                Integer lineNumber = lineNumbers.get(label);
+                if (lineNumber != null && !lineNumber.equals(lastLineNumber)) {
+                    lastLineNumber = lineNumber;
+                    lastLocation = new InstructionLocation(fileName, lastLineNumber);
+                }
+            }
             if (builtInstructions != null) {
+                for (Instruction insn : builtInstructions) {
+                    insn.setLocation(lastLocation);
+                }
                 basicBlock.getInstructions().addAll(builtInstructions);
             }
         }
@@ -347,11 +356,6 @@ public class ProgramParser implements VariableDebugInformation {
     }
 
     private void addInstruction(Instruction insn) {
-        if (lineNumberChanged) {
-            lastInsnLocation = new InstructionLocation(fileName, currentLineNumber);
-            lineNumberChanged = false;
-        }
-        insn.setLocation(lastInsnLocation);
         builder.add(insn);
     }
 
@@ -602,11 +606,6 @@ public class ProgramParser implements VariableDebugInformation {
 
         @Override
         public void visitLabel(Label label) {
-            Integer lineNumber = lineNumbers.get(label);
-            if (lineNumber != null) {
-                currentLineNumber = lineNumber;
-                lineNumberChanged = true;
-            }
         }
 
         private void emitBranching(BranchingCondition condition, int value, int target) {