C: add stack trace deobfuscation tool

core/src/main/java/org/teavm/backend/c/util/Deobfuscator.java

@@ -0,0 +1,258 @@
+/*
+ *  Copyright 2019 konsoletyper.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.backend.c.util;
+
+import java.io.BufferedInputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import org.teavm.backend.c.util.json.JsonAllErrorVisitor;
+import org.teavm.backend.c.util.json.JsonArrayVisitor;
+import org.teavm.backend.c.util.json.JsonErrorReporter;
+import org.teavm.backend.c.util.json.JsonParser;
+import org.teavm.backend.c.util.json.JsonPropertyVisitor;
+import org.teavm.backend.c.util.json.JsonVisitingConsumer;
+import org.teavm.backend.c.util.json.JsonVisitor;
+
+public class Deobfuscator {
+    private Map<Integer, CallSite> callSites = new HashMap<>();
+
+    public Deobfuscator(Reader reader) throws IOException {
+        CallSiteVisitor visitor = new CallSiteVisitor();
+        new JsonParser(new JsonVisitingConsumer(new JsonArrayVisitor(visitor))).parse(reader);
+        visitor.flush();
+    }
+
+    public Location[] getLocations(int callSiteId) {
+        CallSite callSite = callSites.get(callSiteId);
+        if (callSite == null) {
+            return null;
+        }
+
+        Location[] result = new Location[callSite.locations.length];
+        for (int i = 0; i < result.length; ++i) {
+            result[i] = callSite.locations[i].clone();
+        }
+        return result;
+    }
+
+    public String deobfuscate(Reader text) throws IOException {
+        StringBuilder result = new StringBuilder();
+
+        String expectedPrefix = "    at Obfuscated.obfuscated(Obfuscated.java:";
+        int expectedPrefixPos = 0;
+        boolean isInNumber = false;
+        boolean expectingLineEnd = false;
+        StringBuilder sb = new StringBuilder();
+
+        while (true) {
+            int c = text.read();
+
+            if (expectedPrefixPos >= 0) {
+                if (expectedPrefix.charAt(expectedPrefixPos) == c) {
+                    expectedPrefixPos++;
+                    if (expectedPrefixPos == expectedPrefix.length()) {
+                        expectedPrefixPos = -1;
+                        isInNumber = true;
+                    }
+                    continue;
+                }
+                result.append(expectedPrefix, 0, expectedPrefixPos);
+                expectedPrefixPos = -1;
+            } else if (isInNumber) {
+                if (c >= '0' && c <= '9') {
+                    sb.append((char) c);
+                    continue;
+                } else if (c == ')') {
+                    isInNumber = false;
+                    expectingLineEnd = true;
+                    continue;
+                }
+                isInNumber = false;
+                result.append(expectedPrefix).append(sb);
+            }
+
+            if (c == '\r' || c == '\n' || c < 0) {
+                if (expectingLineEnd) {
+                    int callSiteId = Integer.parseInt(sb.toString());
+                    Location[] locations = getLocations(callSiteId);
+                    if (locations == null) {
+                        result.append(expectedPrefix).append(sb).append(')');
+                    } else {
+                        boolean first = true;
+                        for (Location location : locations) {
+                            if (!first) {
+                                result.append('\n');
+                            }
+                            first = false;
+                            result.append("    ");
+                            result.append(location.className).append('.').append(location.methodName).append('(');
+                            if (location.fileName != null & location.line >= 0) {
+                                result.append(location.fileName).append(':').append(location.line);
+                            } else {
+                                result.append("Unknown location");
+                            }
+                            result.append(")");
+                        }
+                    }
+                    sb.setLength(0);
+                }
+                expectingLineEnd = false;
+                expectedPrefixPos = 0;
+            }
+            if (c < 0) {
+                break;
+            }
+            result.append((char) c);
+        }
+
+        return result.toString();
+    }
+
+    class CallSiteVisitor extends JsonAllErrorVisitor {
+        CallSite callSite;
+        List<Location> locations = new ArrayList<>();
+        Location location;
+        JsonPropertyVisitor propertyVisitor = new JsonPropertyVisitor(false);
+        JsonPropertyVisitor locationPropertyVisitor = new JsonPropertyVisitor(false);
+
+        CallSiteVisitor() {
+            propertyVisitor.addProperty("id", new JsonAllErrorVisitor() {
+                @Override
+                public void intValue(JsonErrorReporter reporter, long value) {
+                    callSite.id = (int) value;
+                }
+            });
+            propertyVisitor.addProperty("locations", new JsonArrayVisitor(locationVisitor));
+
+            locationPropertyVisitor.addProperty("file", new JsonAllErrorVisitor() {
+                @Override
+                public void stringValue(JsonErrorReporter reporter, String value) {
+                    location.fileName = value;
+                }
+
+                @Override
+                public void nullValue(JsonErrorReporter reporter) {
+                    location.fileName = null;
+                }
+            });
+
+            locationPropertyVisitor.addProperty("class", new JsonAllErrorVisitor() {
+                @Override
+                public void stringValue(JsonErrorReporter reporter, String value) {
+                    location.className = value;
+                }
+
+                @Override
+                public void nullValue(JsonErrorReporter reporter) {
+                    location.className = null;
+                }
+            });
+
+            locationPropertyVisitor.addProperty("method", new JsonAllErrorVisitor() {
+                @Override
+                public void stringValue(JsonErrorReporter reporter, String value) {
+                    location.methodName = value;
+                }
+
+                @Override
+                public void nullValue(JsonErrorReporter reporter) {
+                    location.methodName = null;
+                }
+            });
+
+            locationPropertyVisitor.addProperty("line", new JsonAllErrorVisitor() {
+                @Override
+                public void intValue(JsonErrorReporter reporter, long value) {
+                    location.line = (int) value;
+                }
+            });
+        }
+
+        @Override
+        public JsonVisitor object(JsonErrorReporter reporter) {
+            flush();
+            callSite = new CallSite();
+            return propertyVisitor;
+        }
+
+        void flush() {
+            if (callSite != null) {
+                callSites.put(callSite.id, callSite);
+                callSite.locations = locations.toArray(new Location[0]);
+                locations.clear();
+            }
+        }
+
+        JsonAllErrorVisitor locationVisitor = new JsonAllErrorVisitor() {
+            @Override
+            public JsonVisitor object(JsonErrorReporter reporter) {
+                location = new Location();
+                locations.add(location);
+                return locationPropertyVisitor;
+            }
+        };
+    }
+
+    public static void main(String[] args) throws IOException {
+        if (args.length != 2) {
+            System.err.println("Two arguments expected (JSON table file, stack trace file)");
+            System.exit(1);
+        }
+
+        Deobfuscator deobfuscator;
+        try (InputStream input = new BufferedInputStream(new FileInputStream(args[0]));
+                Reader reader = new InputStreamReader(input, StandardCharsets.UTF_8)) {
+            deobfuscator = new Deobfuscator(reader);
+        }
+
+        String result;
+        try (InputStream input = new BufferedInputStream(new FileInputStream(args[1]));
+                Reader reader = new InputStreamReader(input, StandardCharsets.UTF_8)) {
+            result = deobfuscator.deobfuscate(reader);
+        }
+
+        System.out.println(result);
+    }
+
+    static class CallSite {
+        int id;
+        Location[] locations;
+    }
+
+    public static class Location implements Cloneable {
+        public String className;
+        public String methodName;
+        public String fileName;
+        public int line = -1;
+
+        @Override
+        protected Location clone() {
+            try {
+                return (Location) super.clone();
+            } catch (CloneNotSupportedException e) {
+                throw new AssertionError(e);
+            }
+        }
+    }
+}