From bd2d2cb49bc6c4dfe3d16bc4f47d2fd2af011d47 Mon Sep 17 00:00:00 2001
From: Alexey Andreev <konsoletyper@gmail.com>
Date: Mon, 28 Aug 2023 13:18:26 +0200
Subject: [PATCH] wasm: fix exceptions in DWARF generator

---
 .../wasm/generate/DwarfClassGenerator.java    | 16 ++++++++++
 .../wasm/generate/DwarfFunctionGenerator.java | 29 +++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/DwarfClassGenerator.java b/core/src/main/java/org/teavm/backend/wasm/generate/DwarfClassGenerator.java
index 24238699b..e5976b5a1 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/DwarfClassGenerator.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/DwarfClassGenerator.java
@@ -46,11 +46,13 @@ import static org.teavm.backend.wasm.dwarf.DwarfConstants.DW_TAG_POINTER_TYPE;
 import static org.teavm.backend.wasm.dwarf.DwarfConstants.DW_TAG_STRUCTURE_TYPE;
 import static org.teavm.backend.wasm.dwarf.DwarfConstants.DW_TAG_UNSPECIFIED_TYPE;
 import static org.teavm.backend.wasm.dwarf.DwarfConstants.DW_TAG_VARIABLE;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Queue;
 import org.teavm.backend.wasm.blob.Blob;
 import org.teavm.backend.wasm.debug.info.VariableType;
 import org.teavm.backend.wasm.dwarf.DwarfAbbreviation;
@@ -82,6 +84,7 @@ public class DwarfClassGenerator {
     private ClassType classClass;
     private DwarfFunctionGenerator functionGen;
     private DwarfPlaceholder fakeClassPtrStruct;
+    private Queue<Subprogram> subprogramsToPrepare = new ArrayDeque<>();
 
     public DwarfClassGenerator(DwarfInfoWriter writer, DwarfStrings strings) {
         this.writer = writer;
@@ -137,6 +140,7 @@ public class DwarfClassGenerator {
 
     public void registerSubprogram(String functionName, Subprogram subprogram) {
         subprogramsByFunctionName.put(functionName, subprogram);
+        subprogramsToPrepare.add(subprogram);
     }
 
     public Subprogram getSubprogram(String functionName) {
@@ -146,6 +150,12 @@ public class DwarfClassGenerator {
     public void write() {
         classClass = getClass("java.lang.Class");
         createFakeClassPtrStruct();
+        for (var subprogram : rootSubprograms) {
+            subprogram.prepare();
+        }
+        while (!subprogramsToPrepare.isEmpty()) {
+            subprogramsToPrepare.remove().prepare();
+        }
         root.writeChildren();
         for (var subprogram : rootSubprograms) {
             subprogram.write();
@@ -484,6 +494,12 @@ public class DwarfClassGenerator {
             this.descriptor = descriptor;
         }
 
+        private void prepare() {
+            if (functionGen != null) {
+                functionGen.prepareContent(this);
+            }
+        }
+
         private void write() {
             if (function != null) {
                 functionGen.writeContent(this);
diff --git a/core/src/main/java/org/teavm/backend/wasm/generate/DwarfFunctionGenerator.java b/core/src/main/java/org/teavm/backend/wasm/generate/DwarfFunctionGenerator.java
index 29c82f753..2811dec92 100644
--- a/core/src/main/java/org/teavm/backend/wasm/generate/DwarfFunctionGenerator.java
+++ b/core/src/main/java/org/teavm/backend/wasm/generate/DwarfFunctionGenerator.java
@@ -48,6 +48,35 @@ public class DwarfFunctionGenerator {
         this.strings = strings;
     }
 
+    public void prepareContent(DwarfClassGenerator.Subprogram subprogram) {
+        if (subprogram.function == null || subprogram.function.getName() == null) {
+            return;
+        }
+        var descriptor = subprogram.descriptor;
+        if (descriptor == null) {
+            return;
+        }
+        var function = subprogram.function;
+
+        var offset = subprogram.isStatic ? 0 : 1;
+        int count = Math.min(function.getLocalVariables().size() - offset, descriptor.parameterCount());
+        for (var i = 0; i < count; ++i) {
+            var local = function.getLocalVariables().get(i + offset);
+            if (local.getName() == null) {
+                continue;
+            }
+            classGen.getTypePtr(descriptor.parameterType(i));
+        }
+
+        for (var i = count + offset; i < function.getLocalVariables().size(); ++i) {
+            var local = function.getLocalVariables().get(i);
+            if (local.getName() == null || local.getJavaType() == null) {
+                continue;
+            }
+            classGen.getTypePtr(local.getJavaType());
+        }
+    }
+
     public void writeContent(DwarfClassGenerator.Subprogram subprogram) {
         if (subprogram.function.getName() == null) {
             return;