diff --git a/classlib/src/main/java/org/teavm/classlib/impl/IntegerUtil.java b/classlib/src/main/java/org/teavm/classlib/impl/IntegerUtil.java
index 296c3b1c7..97ab6e6a3 100644
--- a/classlib/src/main/java/org/teavm/classlib/impl/IntegerUtil.java
+++ b/classlib/src/main/java/org/teavm/classlib/impl/IntegerUtil.java
@@ -49,7 +49,7 @@ public final class IntegerUtil {
         int sz = (Long.SIZE - Long.numberOfLeadingZeros(value) + radixLog2 - 1) / radixLog2;
         char[] chars = new char[sz];
 
-        long pos = (sz - 1) * radixLog2;
+        int pos = (sz - 1) * radixLog2;
         int target = 0;
         while (pos >= 0) {
             chars[target++] = Character.forDigit((int) (value >>> pos) & mask, radix);
diff --git a/classlib/src/main/java/org/teavm/classlib/impl/currency/CountriesGenerator.java b/classlib/src/main/java/org/teavm/classlib/impl/currency/CountriesGenerator.java
index 522c8cae1..03508ed88 100644
--- a/classlib/src/main/java/org/teavm/classlib/impl/currency/CountriesGenerator.java
+++ b/classlib/src/main/java/org/teavm/classlib/impl/currency/CountriesGenerator.java
@@ -20,20 +20,22 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import org.teavm.model.MethodReference;
-import org.teavm.platform.metadata.*;
+import org.teavm.platform.metadata.MetadataGenerator;
+import org.teavm.platform.metadata.MetadataGeneratorContext;
+import org.teavm.platform.metadata.Resource;
+import org.teavm.platform.metadata.ResourceMap;
+import org.teavm.platform.metadata.StringResource;
 
 public class CountriesGenerator implements MetadataGenerator {
     @Override
     public Resource generateMetadata(MetadataGeneratorContext context, MethodReference method) {
         try (InputStream input = new BufferedInputStream(context.getClassLoader().getResourceAsStream(
                 "org/teavm/classlib/impl/currency/iso3166.csv"))) {
-            if (input == null) {
-                throw new AssertionError("ISO 3166 table was not found");
-            }
-            try (BufferedReader reader = new BufferedReader(new InputStreamReader(input, "UTF-8"))) {
+            try (BufferedReader reader = new BufferedReader(new InputStreamReader(input, StandardCharsets.UTF_8))) {
                 return readIso3166(context, reader);
             }
         } catch (IOException e) {
@@ -77,7 +79,7 @@ public class CountriesGenerator implements MetadataGenerator {
                                 + ": closing quote not found");
                     }
                     if (next + 1 == row.length() || row.charAt(next + 1) != '"') {
-                        sb.append(row.substring(index, next));
+                        sb.append(row, index, next);
                         index = next + 1;
                         break;
                     }
@@ -100,6 +102,6 @@ public class CountriesGenerator implements MetadataGenerator {
                 }
             }
         }
-        return values.toArray(new String[values.size()]);
+        return values.toArray(new String[0]);
     }
 }
diff --git a/classlib/src/main/java/org/teavm/classlib/impl/unicode/CLDRReader.java b/classlib/src/main/java/org/teavm/classlib/impl/unicode/CLDRReader.java
index c4b547de5..23d8208ad 100644
--- a/classlib/src/main/java/org/teavm/classlib/impl/unicode/CLDRReader.java
+++ b/classlib/src/main/java/org/teavm/classlib/impl/unicode/CLDRReader.java
@@ -105,6 +105,9 @@ public class CLDRReader {
                     readLikelySubtags(input);
                 }
                 int objectIndex = entry.getName().lastIndexOf('/');
+                if (objectIndex < 0) {
+                    continue;
+                }
                 String objectName = entry.getName().substring(objectIndex + 1);
                 String localeName = entry.getName().substring(0, objectIndex);
                 if (localeName.startsWith("/")) {
diff --git a/classlib/src/main/java/org/teavm/classlib/impl/unicode/UnicodeHelper.java b/classlib/src/main/java/org/teavm/classlib/impl/unicode/UnicodeHelper.java
index 0a4779f12..9ad874997 100644
--- a/classlib/src/main/java/org/teavm/classlib/impl/unicode/UnicodeHelper.java
+++ b/classlib/src/main/java/org/teavm/classlib/impl/unicode/UnicodeHelper.java
@@ -89,7 +89,7 @@ public final class UnicodeHelper {
             byte b = bytes[i];
             if (i < bytes.length - 1 && b == bytes[i + 1]) {
                 int count = 0;
-                while (count < 16384 && i < bytes.length && bytes[i + count] == b) {
+                while (count < 16384 && bytes[i + count] == b) {
                     ++count;
                 }
                 i += count;
diff --git a/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedInputStream.java b/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedInputStream.java
index 9cf821988..dab700985 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedInputStream.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedInputStream.java
@@ -187,7 +187,7 @@ public class TBufferedInputStream extends TFilterInputStream {
                     }
                 }
 
-                read = count - pos >= required ? required : count - pos;
+                read = Math.min(count - pos, required);
                 System.arraycopy(localBuf, pos, buffer, offset, read);
                 pos += read;
             }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/io/TFile.java b/classlib/src/main/java/org/teavm/classlib/java/io/TFile.java
index 31bba071a..1904bd578 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/io/TFile.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/io/TFile.java
@@ -563,7 +563,6 @@ public class TFile implements Serializable, Comparable<TFile> {
     }
 
     private static String fixSlashes(String origPath) {
-        int uncIndex = 0;
         int length = origPath.length();
         int newLength = 0;
 
@@ -579,7 +578,7 @@ public class TFile implements Serializable, Comparable<TFile> {
         for (int i = 0; i < length; i++) {
             char pathChar = newPath[i];
             if (pathChar == '/' || pathChar == separatorChar) {
-                if (!foundSlash || i == uncIndex) {
+                if (!foundSlash || i == 0) {
                     newPath[newLength++] = separatorChar;
                     foundSlash = true;
                 }
@@ -588,7 +587,7 @@ public class TFile implements Serializable, Comparable<TFile> {
                 foundSlash = false;
             }
         }
-        if (foundSlash && (newLength > uncIndex + 1 || newLength == 2 && newPath[0] != '/')) {
+        if (foundSlash && (newLength > 1 || newPath[0] != '/')) {
             newLength--;
         }
 
diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
index 2bd030d25..acde33d55 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
@@ -229,7 +229,6 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
         int intPart = 1;
         int sz = 1; // Decimal point always included
         if (negative) {
-            negative = true;
             ++sz; // including '-' sign of mantissa
         }
 
@@ -246,7 +245,7 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
                 intPart = exp + 1;
                 digits = Math.max(digits, intPart + 1);
                 exp = 0;
-            } else if (exp < 0) {
+            } else {
                 mantissa /= Constants.intPowersOfTen[-exp];
                 digits -= exp;
                 exp = 0;
@@ -373,7 +372,7 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
                 intPart = exp + 1;
                 digits = Math.max(digits, intPart + 1);
                 exp = 0;
-            } else if (exp < 0) {
+            } else {
                 mantissa /= Constants.longPowersOfTen[-exp];
                 digits -= exp;
                 exp = 0;
diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TObject.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TObject.java
index e14c0973e..f69d22231 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TObject.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TObject.java
@@ -175,9 +175,7 @@ public class TObject {
         if (monitor.enteringThreads != null && !monitor.enteringThreads.isEmpty()) {
             PlatformQueue<PlatformRunnable> enteringThreads = monitor.enteringThreads;
             PlatformRunnable r = enteringThreads.remove();
-            if (enteringThreads == null) {
-                monitor.enteringThreads = null;
-            }
+            monitor.enteringThreads = null;
             r.run();
         }
     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/math/TBitLevel.java b/classlib/src/main/java/org/teavm/classlib/java/math/TBitLevel.java
index b04b96db7..b2dd30fc4 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/math/TBitLevel.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/math/TBitLevel.java
@@ -287,7 +287,6 @@ class TBitLevel {
         }
         if (count == 0) {
             System.arraycopy(source, intCount, result, 0, resultLen);
-            i = resultLen;
         } else {
             int leftShiftCount = 32 - count;
 
@@ -336,7 +335,6 @@ class TBitLevel {
                     for (i = intCount + 1; i < firstNonZeroDigit; i++) {
                         resDigits[i] = -1;
                     }
-                    resDigits[i] = resDigits[i]--;
                 } else {
                     i = intCount;
                     resDigits[i] = -((-resDigits[intCount]) ^ bitNumber);
diff --git a/classlib/src/main/java/org/teavm/classlib/java/math/TLogical.java b/classlib/src/main/java/org/teavm/classlib/java/math/TLogical.java
index 18374a618..f74c340bd 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/math/TLogical.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/math/TLogical.java
@@ -496,7 +496,7 @@ class TLogical {
         int[] resDigits = new int[resLength];
 
         int i = Math.min(longer.getFirstNonzeroDigit(), shorter.getFirstNonzeroDigit());
-        for (i = 0; i < shorter.numberLength; i++) {
+        for (; i < shorter.numberLength; i++) {
             resDigits[i] = longer.digits[i] | shorter.digits[i];
         }
         for (; i < resLength; i++) {
diff --git a/classlib/src/main/java/org/teavm/classlib/java/net/TURLStreamHandler.java b/classlib/src/main/java/org/teavm/classlib/java/net/TURLStreamHandler.java
index fffccada2..e1d211633 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/net/TURLStreamHandler.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/net/TURLStreamHandler.java
@@ -98,9 +98,7 @@ public abstract class TURLStreamHandler {
             } else {
                 host = parseString.substring(hostIdx, portIdx);
                 String portString = parseString.substring(portIdx + 1, hostEnd);
-                if (portString.length() == 0) {
-                    port = -1;
-                } else {
+                if (!portString.isEmpty()) {
                     port = Integer.parseInt(portString);
                 }
             }
@@ -189,7 +187,7 @@ public abstract class TURLStreamHandler {
             if (dirIndex != 0) {
                 path = path.substring(0, path.lastIndexOf('/', dirIndex - 1)) + path.substring(dirIndex + 3);
             } else {
-                path = path.substring(dirIndex + 3);
+                path = path.substring(3);
             }
         }
 
diff --git a/classlib/src/main/java/org/teavm/classlib/java/nio/charset/TCharset.java b/classlib/src/main/java/org/teavm/classlib/java/nio/charset/TCharset.java
index fee92a1b8..c64d1a184 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/nio/charset/TCharset.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/nio/charset/TCharset.java
@@ -60,7 +60,7 @@ public abstract class TCharset implements Comparable<TCharset> {
     }
 
     private static boolean isValidCharsetStart(char c) {
-        return c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' || c <= 'Z';
+        return c >= '0' && c <= '9' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z';
     }
 
     public static TCharset forName(String charsetName) {
diff --git a/classlib/src/main/java/org/teavm/classlib/java/text/TMessageFormat.java b/classlib/src/main/java/org/teavm/classlib/java/text/TMessageFormat.java
index 357cbfbef..0762fa6de 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/text/TMessageFormat.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/text/TMessageFormat.java
@@ -63,7 +63,7 @@ public class TMessageFormat extends TFormat {
                     if (ch == '}' || ch == ',') {
                         break;
                     }
-                    if (ch < '0' && ch > '9') {
+                    if (ch < '0' || ch > '9') {
                         throw new IllegalArgumentException("Invalid argument number");
                     }
                     arg = arg * 10 + (ch - '0');
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TEnumMap.java b/classlib/src/main/java/org/teavm/classlib/java/util/TEnumMap.java
index 7bad40903..ae81f39f1 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TEnumMap.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TEnumMap.java
@@ -216,7 +216,7 @@ public class TEnumMap<K extends Enum<K>, V> extends AbstractMap<K, V> implements
                     }
                     int index = ((Enum<?>) o).ordinal();
                     if (provided[index]) {
-                        provided[index] = true;
+                        provided[index] = false;
                         data[index] = null;
                         size--;
                         return true;
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TFormatter.java b/classlib/src/main/java/org/teavm/classlib/java/util/TFormatter.java
index 01fb15661..6db23c5ca 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TFormatter.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TFormatter.java
@@ -297,7 +297,7 @@ public final class TFormatter implements Closeable, Flushable {
                 formatGivenString(upperCase, "null");
                 return;
             } else {
-                throw new IllegalFormatConversionException(specifier, arg != null ? arg.getClass() : null);
+                throw new IllegalFormatConversionException(specifier, arg.getClass());
             }
 
             formatGivenString(upperCase, new String(Character.toChars(c)));
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TGregorianCalendar.java b/classlib/src/main/java/org/teavm/classlib/java/util/TGregorianCalendar.java
index 0766641d1..73afe7bb5 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TGregorianCalendar.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TGregorianCalendar.java
@@ -917,7 +917,6 @@ public class TGregorianCalendar extends TCalendar {
             lastYearSkew = 0;
             currentYearSkew = julianSkew;
         }
-        isCached = false;
     }
 
     @Override
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TProperties.java b/classlib/src/main/java/org/teavm/classlib/java/util/TProperties.java
index d1bde48a0..d028b67e9 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TProperties.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TProperties.java
@@ -291,7 +291,7 @@ public class TProperties extends THashtable<Object, Object> {
                     }
                     break;
                 }
-                if (nextChar < 256 && Character.isWhitespace(nextChar)) {
+                if (Character.isWhitespace(nextChar)) {
                     if (mode == CONTINUE) {
                         mode = IGNORE;
                     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TTimeZone.java b/classlib/src/main/java/org/teavm/classlib/java/util/TTimeZone.java
index ca8eff4db..5647b4b10 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TTimeZone.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TTimeZone.java
@@ -329,8 +329,8 @@ public abstract class TTimeZone implements Serializable, Cloneable {
                             return (TTimeZone) GMT.clone();
                         }
                         raw += minute * 60000;
-                    } else if (hour >= 30 || index > 6) {
-                        raw = (hour / 100 * 3600000) + (hour % 100 * 60000);
+                    } else if (index > 6) {
+                        raw = hour * 60000;
                     }
                     if (sign == '-') {
                         raw = -raw;
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TTimer.java b/classlib/src/main/java/org/teavm/classlib/java/util/TTimer.java
index bb066f7a6..9991ae122 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TTimer.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TTimer.java
@@ -23,7 +23,7 @@ import org.teavm.jso.browser.Window;
 
 public class TTimer extends TObject {
     TSet<TTimerTask> tasks = new THashSet<>();
-    private boolean cancelled;
+    private volatile boolean cancelled;
 
     public TTimer() {
     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/TVector.java b/classlib/src/main/java/org/teavm/classlib/java/util/TVector.java
index 6c1ac8e91..acf3dfbbf 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/TVector.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/TVector.java
@@ -39,7 +39,7 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
         if (capacity < 0) {
             throw new IllegalArgumentException();
         }
-        elementData = newElementArray(capacity);
+        elementData = new Object[capacity];
         elementCount = 0;
         this.capacityIncrement = capacityIncrement;
     }
@@ -52,11 +52,6 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
         }
     }
 
-    @SuppressWarnings("unchecked")
-    private E[] newElementArray(int size) {
-        return (E[]) new Object[size];
-    }
-
     @Override
     public void add(int location, E object) {
         insertElementAt(object, location);
@@ -179,7 +174,7 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
     public synchronized void ensureCapacity(int minimumCapacity) {
         if (elementData.length < minimumCapacity) {
             int next = (capacityIncrement <= 0 ? elementData.length : capacityIncrement) + elementData.length;
-            grow(minimumCapacity > next ? minimumCapacity : next);
+            grow(Math.max(minimumCapacity, next));
         }
     }
 
@@ -222,7 +217,7 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
     }
 
     private void grow(int newCapacity) {
-        E[] newData = newElementArray(newCapacity);
+        Object[] newData = new Object[newCapacity];
         // Assumes elementCount is <= newCapacity
         assert elementCount <= newCapacity;
         System.arraycopy(elementData, 0, newData, 0, elementCount);
@@ -243,20 +238,20 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
             adding = capacityIncrement;
         }
 
-        E[] newData = newElementArray(elementData.length + adding);
+        Object[] newData = new Object[elementData.length + adding];
         System.arraycopy(elementData, 0, newData, 0, elementCount);
         elementData = newData;
     }
 
     private void growBy(int required) {
-        int adding = 0;
+        int adding;
         if (capacityIncrement <= 0) {
             adding = elementData.length;
             if (adding == 0) {
                 adding = required;
             }
             while (adding < required) {
-                adding += adding;
+                adding *= 2;
             }
         } else {
             adding = (required / capacityIncrement) * capacityIncrement;
@@ -264,7 +259,7 @@ public class TVector<E> extends TAbstractList<E> implements TList<E>, TRandomAcc
                 adding += capacityIncrement;
             }
         }
-        E[] newData = newElementArray(elementData.length + adding);
+        Object[] newData = new Object[elementData.length + adding];
         System.arraycopy(elementData, 0, newData, 0, elementCount);
         elementData = newData;
     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/TArrayBlockingQueue.java b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/TArrayBlockingQueue.java
index 80ceb11e7..f3abf38db 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/TArrayBlockingQueue.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/TArrayBlockingQueue.java
@@ -414,17 +414,15 @@ public class TArrayBlockingQueue<E> extends TAbstractQueue<E> implements TBlocki
         if (waitHandlers == null) {
             return;
         }
-        if (waitHandlers != null) {
-            while (!waitHandlers.isEmpty()) {
-                WaitHandler handler = waitHandlers.remove();
-                if (PlatformDetector.isLowLevel()) {
-                    EventQueue.offer(handler::changed);
-                } else {
-                    Platform.postpone(handler::changed);
-                }
+        while (!waitHandlers.isEmpty()) {
+            WaitHandler handler = waitHandlers.remove();
+            if (PlatformDetector.isLowLevel()) {
+                EventQueue.offer(handler::changed);
+            } else {
+                Platform.postpone(handler::changed);
             }
-            waitHandlers = null;
         }
+        waitHandlers = null;
     }
 
     @Async
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicInteger.java b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicInteger.java
index 6a3690119..1ca9d08b8 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicInteger.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicInteger.java
@@ -19,9 +19,10 @@ import java.io.Serializable;
 import java.util.function.IntBinaryOperator;
 import java.util.function.IntUnaryOperator;
 
+@SuppressWarnings("NonAtomicOperationOnVolatileField")
 public class TAtomicInteger extends Number implements Serializable {
     private int value;
-    private int version;
+    private volatile int version;
 
     public TAtomicInteger() {
     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicLong.java b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicLong.java
index f0834c3a8..b1ce364ff 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicLong.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/concurrent/atomic/TAtomicLong.java
@@ -19,9 +19,10 @@ import java.io.Serializable;
 import java.util.function.LongBinaryOperator;
 import java.util.function.LongUnaryOperator;
 
+@SuppressWarnings("NonAtomicOperationOnVolatileField")
 public class TAtomicLong extends Number implements Serializable {
     private long value;
-    private int version;
+    private volatile int version;
 
     public TAtomicLong() {
     }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/jar/TInitManifest.java b/classlib/src/main/java/org/teavm/classlib/java/util/jar/TInitManifest.java
index bf57e7727..6e1540da4 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/jar/TInitManifest.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/jar/TInitManifest.java
@@ -120,7 +120,6 @@ class TInitManifest {
     }
 
     private void readName() throws IOException {
-        int i = 0;
         int mark = pos;
 
         while (pos < buf.length) {
@@ -142,9 +141,6 @@ class TInitManifest {
                 throw new IOException();
             }
         }
-        if (i > 0) {
-            throw new IOException();
-        }
     }
 
     private void readValue() throws IOException {
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/logging/TLogger.java b/classlib/src/main/java/org/teavm/classlib/java/util/logging/TLogger.java
index 69e71028b..cffa2e0d9 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/logging/TLogger.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/logging/TLogger.java
@@ -95,7 +95,7 @@ public class TLogger {
                 break;
             }
             if (message.charAt(next) != '}') {
-                sb.append(message.substring(index, next));
+                sb.append(message, index, next);
                 index = next;
                 continue;
             }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/regex/TDotQuantifierSet.java b/classlib/src/main/java/org/teavm/classlib/java/util/regex/TDotQuantifierSet.java
index c36166314..1e193c612 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/regex/TDotQuantifierSet.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/regex/TDotQuantifierSet.java
@@ -92,7 +92,7 @@ class TDotQuantifierSet extends TQuantifierSet {
                 nextSearch = strLength;
             }
             nextSearch = next.findBack(res, nextSearch, testString, matchResult);
-            res = (res < nextSearch) ? nextSearch : res;
+            res = Math.max(res, nextSearch);
         } else {
             return -1;
         }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/regex/TSupplRangeSet.java b/classlib/src/main/java/org/teavm/classlib/java/util/regex/TSupplRangeSet.java
index 3c7d81dd6..de2b856e1 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/regex/TSupplRangeSet.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/regex/TSupplRangeSet.java
@@ -123,13 +123,12 @@ class TSupplRangeSet extends TJointSet {
     @Override
     public int matches(int stringIndex, CharSequence testString, TMatchResultImpl matchResult) {
         int strLength = matchResult.getRightBound();
-        int offset = -1;
 
         if (stringIndex < strLength) {
             char high = testString.charAt(stringIndex++);
 
             if (contains(high)) {
-                offset = next.matches(stringIndex, testString, matchResult);
+                int offset = next.matches(stringIndex, testString, matchResult);
                 if (offset > 0) {
                     return offset;
                 }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/zip/TInflaterInputStream.java b/classlib/src/main/java/org/teavm/classlib/java/util/zip/TInflaterInputStream.java
index 38d489fb9..2fc48a122 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/zip/TInflaterInputStream.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/zip/TInflaterInputStream.java
@@ -81,7 +81,7 @@ public class TInflaterInputStream extends FilterInputStream {
         }
 
         // avoid int overflow, check null buffer
-        if (off > buffer.length || nbytes < 0 || off < 0 || buffer.length - off < nbytes) {
+        if (off > buffer.length || buffer.length - off < nbytes) {
             throw new ArrayIndexOutOfBoundsException();
         }
 
diff --git a/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java b/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
index e682b8b3a..6bd14b708 100644
--- a/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
+++ b/core/src/main/java/org/teavm/ast/decompilation/StatementGenerator.java
@@ -342,10 +342,7 @@ class StatementGenerator implements InstructionVisitor {
                 conditions[i] = conditionList.get(i);
             }
             clause.setConditions(conditions);
-            Statement jumpStmt = generateJumpStatement(stmt, target);
-            if (jumpStmt != null) {
-                clause.getBody().add(jumpStmt);
-            }
+            clause.getBody().add(generateJumpStatement(stmt, target));
             stmt.getClauses().add(clause);
         }
         Statement breakStmt = generateJumpStatement(insn.getDefaultTarget());
diff --git a/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java b/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
index 4d683e6ab..fa303637b 100644
--- a/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
+++ b/core/src/main/java/org/teavm/backend/c/generate/ClassGenerator.java
@@ -741,20 +741,22 @@ public class ClassGenerator {
                     break;
             }
 
-            simpleName = cls.getSimpleName();
+            if (cls != null) {
+                simpleName = cls.getSimpleName();
 
-            if (cls.getDeclaringClassName() != null
-                    && context.getDependencies().getClass(cls.getDeclaringClassName()) != null) {
-                declaringClass = "(TeaVM_Class*) &" + context.getNames().forClassInstance(
-                        ValueType.object(cls.getDeclaringClassName()));
-                includes.includeClass(cls.getDeclaringClassName());
-            }
+                if (cls.getDeclaringClassName() != null
+                        && context.getDependencies().getClass(cls.getDeclaringClassName()) != null) {
+                    declaringClass = "(TeaVM_Class*) &" + context.getNames().forClassInstance(
+                            ValueType.object(cls.getDeclaringClassName()));
+                    includes.includeClass(cls.getDeclaringClassName());
+                }
 
-            if (cls.getOwnerName() != null
-                    && context.getDependencies().getClass(cls.getOwnerName()) != null) {
-                enclosingClass = "(TeaVM_Class*) &" + context.getNames().forClassInstance(
-                        ValueType.object(cls.getOwnerName()));
-                includes.includeClass(cls.getOwnerName());
+                if (cls.getOwnerName() != null
+                        && context.getDependencies().getClass(cls.getOwnerName()) != null) {
+                    enclosingClass = "(TeaVM_Class*) &" + context.getNames().forClassInstance(
+                            ValueType.object(cls.getOwnerName()));
+                    includes.includeClass(cls.getOwnerName());
+                }
             }
 
         } else if (type instanceof ValueType.Array) {
diff --git a/core/src/main/java/org/teavm/backend/c/generate/CodeGenerator.java b/core/src/main/java/org/teavm/backend/c/generate/CodeGenerator.java
index d1b60cf7c..0ecadc19e 100644
--- a/core/src/main/java/org/teavm/backend/c/generate/CodeGenerator.java
+++ b/core/src/main/java/org/teavm/backend/c/generate/CodeGenerator.java
@@ -42,7 +42,6 @@ public class CodeGenerator {
         this.writer = writer;
         this.names = context.getNames();
         this.includes = includes;
-        this.classContext = classContext;
     }
 
     public ClassGenerationContext getClassContext() {
diff --git a/core/src/main/java/org/teavm/backend/c/intrinsic/AddressIntrinsic.java b/core/src/main/java/org/teavm/backend/c/intrinsic/AddressIntrinsic.java
index 8e8557e5d..1d6cffe48 100644
--- a/core/src/main/java/org/teavm/backend/c/intrinsic/AddressIntrinsic.java
+++ b/core/src/main/java/org/teavm/backend/c/intrinsic/AddressIntrinsic.java
@@ -178,7 +178,7 @@ public class AddressIntrinsic implements Intrinsic {
                     context.writer().print(" * sizeof(");
 
                     if (className != null) {
-                        ClassReader cls = className != null ? context.classes().get(className) : null;
+                        ClassReader cls = context.classes().get(className);
                         CodeGeneratorUtil.printClassReference(context.writer(), context.includes(),
                                 context.names(), cls, className);
                     } else {
diff --git a/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java b/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
index d33307469..fa71227a7 100644
--- a/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
+++ b/core/src/main/java/org/teavm/backend/javascript/codegen/DefaultNamingStrategy.java
@@ -156,11 +156,9 @@ public class DefaultNamingStrategy implements NamingStrategy {
             if (clsReader == null) {
                 break;
             }
-            if (clsReader != null) {
-                FieldReader fieldReader = clsReader.getField(fieldRef.getFieldName());
-                if (fieldReader != null) {
-                    return fieldReader.getReference();
-                }
+            FieldReader fieldReader = clsReader.getField(fieldRef.getFieldName());
+            if (fieldReader != null) {
+                return fieldReader.getReference();
             }
             cls = clsReader.getParent();
         }
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
index e74416b9b..a777f9943 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/Renderer.java
@@ -984,16 +984,14 @@ public class Renderer implements RenderingManager {
                 }
                 variableNames.add(context.pointerName());
                 variableNames.add(context.tempVarName());
-                if (!variableNames.isEmpty()) {
-                    writer.append("var ");
-                    for (int i = 0; i < variableNames.size(); ++i) {
-                        if (i > 0) {
-                            writer.append(",").ws();
-                        }
-                        writer.append(variableNames.get(i));
+                writer.append("var ");
+                for (int i = 0; i < variableNames.size(); ++i) {
+                    if (i > 0) {
+                        writer.append(",").ws();
                     }
-                    writer.append(";").softNewLine();
+                    writer.append(variableNames.get(i));
                 }
+                writer.append(";").softNewLine();
 
                 int firstToSave = 0;
                 if (methodNode.getModifiers().contains(ElementModifier.STATIC)) {
diff --git a/core/src/main/java/org/teavm/backend/javascript/rendering/StringConstantElimination.java b/core/src/main/java/org/teavm/backend/javascript/rendering/StringConstantElimination.java
index 3e556b245..26324f179 100644
--- a/core/src/main/java/org/teavm/backend/javascript/rendering/StringConstantElimination.java
+++ b/core/src/main/java/org/teavm/backend/javascript/rendering/StringConstantElimination.java
@@ -17,7 +17,6 @@ package org.teavm.backend.javascript.rendering;
 
 import org.mozilla.javascript.Node;
 import org.mozilla.javascript.ast.AstNode;
-import org.mozilla.javascript.ast.AstRoot;
 import org.mozilla.javascript.ast.Block;
 import org.mozilla.javascript.ast.ExpressionStatement;
 import org.mozilla.javascript.ast.NodeVisitor;
@@ -27,7 +26,7 @@ import org.mozilla.javascript.ast.StringLiteral;
 public class StringConstantElimination implements NodeVisitor {
     @Override
     public boolean visit(AstNode astNode) {
-        if (astNode instanceof Block || astNode instanceof Scope || astNode instanceof AstRoot) {
+        if (astNode instanceof Block || astNode instanceof Scope) {
             handle(astNode);
         }
         return true;
diff --git a/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java b/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
index 11ae20626..81f2aa0be 100644
--- a/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
+++ b/core/src/main/java/org/teavm/backend/wasm/WasmTarget.java
@@ -803,9 +803,7 @@ public class WasmTarget implements TeaVMTarget, TeaVMWasmHost {
             block.getBody().add(new WasmStoreInt32(4, new WasmInt32Constant(index), initFlag,
                     WasmInt32Subtype.INT32));
 
-            if (method != null) {
-                block.getBody().add(new WasmCall(classGenerator.names.forMethod(method.getReference())));
-            }
+            block.getBody().add(new WasmCall(classGenerator.names.forMethod(method.getReference())));
 
             if (controller.wasCancelled()) {
                 break;
diff --git a/core/src/main/java/org/teavm/common/DisjointSet.java b/core/src/main/java/org/teavm/common/DisjointSet.java
index 84fd16ee7..36ebd03a1 100644
--- a/core/src/main/java/org/teavm/common/DisjointSet.java
+++ b/core/src/main/java/org/teavm/common/DisjointSet.java
@@ -84,7 +84,7 @@ public class DisjointSet {
             parent[b] = a;
             setSize[a] += setSize[b];
             return a;
-        } else if (rank[b] < rank[a]) {
+        } else if (rank[b] > rank[a]) {
             parent[a] = b;
             setSize[b] += setSize[a];
             return b;
diff --git a/core/src/main/java/org/teavm/common/GraphIndexer.java b/core/src/main/java/org/teavm/common/GraphIndexer.java
index 7273a7093..d11c94d4b 100644
--- a/core/src/main/java/org/teavm/common/GraphIndexer.java
+++ b/core/src/main/java/org/teavm/common/GraphIndexer.java
@@ -80,7 +80,7 @@ public class GraphIndexer {
                 case VISITING:
                     state[node] = VISITED;
                     for (int succ : graph.outgoingEdges(node)) {
-                        if (state[node] == VISITED) {
+                        if (state[succ] == VISITED) {
                             weights[node] += weights[succ];
                         }
                     }
diff --git a/core/src/main/java/org/teavm/common/Promise.java b/core/src/main/java/org/teavm/common/Promise.java
index c86cf6dbb..3900dca13 100644
--- a/core/src/main/java/org/teavm/common/Promise.java
+++ b/core/src/main/java/org/teavm/common/Promise.java
@@ -26,7 +26,6 @@ public class Promise<T> {
     public static final Promise<Void> VOID = Promise.of(null);
 
     private T value;
-    private Promise<T> promise;
     private Throwable error;
     private State state = State.PENDING;
     private List<Then<T>> thenList;
@@ -81,7 +80,6 @@ public class Promise<T> {
         boolean error;
 
         AllVoidFunction(int count) {
-            this.result = result;
             this.count = count;
         }
 
@@ -109,7 +107,6 @@ public class Promise<T> {
         boolean error;
 
         AllFunction(int count) {
-            this.result = result;
             this.count = count;
             list.addAll(Collections.nCopies(count, null));
         }
@@ -124,7 +121,7 @@ public class Promise<T> {
                 }
                 return null;
             };
-        };
+        }
 
         Function<Throwable, Void> catchF = e -> {
             if (!error) {
diff --git a/core/src/main/java/org/teavm/debugging/Debugger.java b/core/src/main/java/org/teavm/debugging/Debugger.java
index 59876b807..ee77157ac 100644
--- a/core/src/main/java/org/teavm/debugging/Debugger.java
+++ b/core/src/main/java/org/teavm/debugging/Debugger.java
@@ -324,8 +324,10 @@ public class Debugger {
                     loc = null;
                 }
                 boolean empty = loc == null || (loc.getFileName() == null && loc.getLine() < 0);
-                MethodReference method = !empty ? debugInformation.getMethodAt(jsFrame.getLocation().getLine(),
-                        jsFrame.getLocation().getColumn()) : null;
+                MethodReference method = !empty && debugInformation != null
+                        ? debugInformation.getMethodAt(jsFrame.getLocation().getLine(),
+                                jsFrame.getLocation().getColumn())
+                        : null;
                 if (!empty || !wasEmpty) {
                     frames.add(new CallFrame(this, jsFrame, loc, method, debugInformation));
                 }
diff --git a/core/src/main/java/org/teavm/debugging/Value.java b/core/src/main/java/org/teavm/debugging/Value.java
index f40afbdd6..516fcdd7b 100644
--- a/core/src/main/java/org/teavm/debugging/Value.java
+++ b/core/src/main/java/org/teavm/debugging/Value.java
@@ -119,18 +119,12 @@ public class Value {
         return vars;
     }
 
-    public boolean hasInnerStructure() {
-        if (getType().equals("long")) {
-            return false;
-        }
-        return jsValue.hasInnerStructure();
+    public Promise<Boolean> hasInnerStructure() {
+        return getType().then(value -> !value.equals("long") && jsValue.hasInnerStructure());
     }
 
-    public String getInstanceId() {
-        if (getType().equals("long")) {
-            return null;
-        }
-        return jsValue.getInstanceId();
+    public Promise<String> getInstanceId() {
+        return getType().then(value -> value.equals("long") ? null : jsValue.getInstanceId());
     }
 
     public JavaScriptValue getOriginalValue() {
diff --git a/core/src/main/java/org/teavm/dependency/DefaultCallGraphNode.java b/core/src/main/java/org/teavm/dependency/DefaultCallGraphNode.java
index 209c70bc2..89e5c71ab 100644
--- a/core/src/main/java/org/teavm/dependency/DefaultCallGraphNode.java
+++ b/core/src/main/java/org/teavm/dependency/DefaultCallGraphNode.java
@@ -94,10 +94,8 @@ class DefaultCallGraphNode implements CallGraphNode {
                 callee.addCaller(singleCallSite);
                 return singleCallSite;
             }
-            if (singleCallSite != null) {
-                if (singleCallSite.singleCalledMethod.getMethod().equals(method)) {
-                    return singleCallSite;
-                }
+            if (singleCallSite.singleCalledMethod.getMethod().equals(method)) {
+                return singleCallSite;
             }
             callSiteMap = new LinkedHashMap<>();
             callSites = new ArrayList<>();
diff --git a/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java b/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
index 0cb0b09ee..d1a46a42c 100644
--- a/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
+++ b/core/src/main/java/org/teavm/dependency/DependencyGraphBuilder.java
@@ -287,7 +287,9 @@ class DependencyGraphBuilder {
             }
             MethodDependency cloneDep = getAnalyzer().linkMethod(CLONE_METHOD);
             cloneDep.addLocation(getCallLocation());
-            arrayNode.connect(cloneDep.getVariable(0));
+            if (arrayNode != null) {
+                arrayNode.connect(cloneDep.getVariable(0));
+            }
             cloneDep.use();
         }
 
diff --git a/core/src/main/java/org/teavm/model/BasicBlock.java b/core/src/main/java/org/teavm/model/BasicBlock.java
index f570d93bc..4716fbf07 100644
--- a/core/src/main/java/org/teavm/model/BasicBlock.java
+++ b/core/src/main/java/org/teavm/model/BasicBlock.java
@@ -384,7 +384,7 @@ public class BasicBlock implements BasicBlockReader, Iterable<Instruction> {
 
         @Override
         public TryCatchBlock set(int index, TryCatchBlock element) {
-            TryCatchBlock oldTryCatch = tryCatchBlocks.get(index);
+            TryCatchBlock oldTryCatch = tryCatchBlocks != null ? tryCatchBlocks.get(index) : null;
             if (oldTryCatch == element) {
                 return oldTryCatch;
             }
diff --git a/core/src/main/java/org/teavm/model/MethodDescriptor.java b/core/src/main/java/org/teavm/model/MethodDescriptor.java
index 5beef6647..bfc439b52 100644
--- a/core/src/main/java/org/teavm/model/MethodDescriptor.java
+++ b/core/src/main/java/org/teavm/model/MethodDescriptor.java
@@ -119,14 +119,14 @@ public class MethodDescriptor implements Serializable {
             return null;
         }
         int index = text.indexOf(')', 1);
-        if (index < 0) {
+        if (index <= 0) {
             return null;
         }
         ValueType[] params = ValueType.parseManyIfPossible(text.substring(1, index));
         if (params == null) {
             return null;
         }
-        ValueType result = ValueType.parse(text.substring(index + 1));
+        ValueType result = ValueType.parseIfPossible(text.substring(index + 1));
         if (result == null) {
             return null;
         }
diff --git a/core/src/main/java/org/teavm/model/ValueType.java b/core/src/main/java/org/teavm/model/ValueType.java
index e19a6540c..253ef4d1e 100644
--- a/core/src/main/java/org/teavm/model/ValueType.java
+++ b/core/src/main/java/org/teavm/model/ValueType.java
@@ -270,7 +270,7 @@ public abstract class ValueType implements Serializable {
         int index = 0;
         while (index < text.length()) {
             int nextIndex = cut(text, index);
-            ValueType type = parse(text.substring(index, nextIndex));
+            ValueType type = parseIfPossible(text.substring(index, nextIndex));
             if (type == null) {
                 return null;
             }
diff --git a/core/src/main/java/org/teavm/model/analysis/ClassInference.java b/core/src/main/java/org/teavm/model/analysis/ClassInference.java
index 6f02869b2..dc7050af2 100644
--- a/core/src/main/java/org/teavm/model/analysis/ClassInference.java
+++ b/core/src/main/java/org/teavm/model/analysis/ClassInference.java
@@ -398,8 +398,6 @@ public class ClassInference {
             if (!outerChanged) {
                 break;
             }
-
-            changed = false;
         }
     }
 
@@ -684,13 +682,7 @@ public class ClassInference {
 
             String expectedType = tryCatch.getExceptionType();
             List<? extends String> thrownTypes = subclassListProvider.getSubclasses(expectedType, false);
-            if (thrownTypes == null) {
-                if (!overflowTypes[exceptionNode]) {
-                    overflowTypes[exceptionNode] = true;
-                    changed = true;
-                    nodeChanged[exceptionNode] = true;
-                }
-            } else {
+            if (thrownTypes != null) {
                 IntHashSet nodeTypes = getNodeTypes(exceptionNode);
                 for (String thrownTypeName : thrownTypes) {
                     int thrownType = getTypeByName(thrownTypeName);
@@ -953,7 +945,7 @@ public class ClassInference {
             overflowType(variable, degree);
         } else {
             String[] types = dep.getTypes();
-            for (String type : dep.getTypes()) {
+            for (String type : types) {
                 if (addType(variable, degree, type)) {
                     break;
                 }
diff --git a/core/src/main/java/org/teavm/model/lowlevel/CallSiteLocation.java b/core/src/main/java/org/teavm/model/lowlevel/CallSiteLocation.java
index 7f5b7ac81..329648ea4 100644
--- a/core/src/main/java/org/teavm/model/lowlevel/CallSiteLocation.java
+++ b/core/src/main/java/org/teavm/model/lowlevel/CallSiteLocation.java
@@ -55,10 +55,10 @@ public class CallSiteLocation {
             List<CallSiteLocation> result = new ArrayList<>();
             InliningInfo inlining = location.getInlining();
             result.add(new CallSiteLocation(
-                    convertFileName(location != null ? location.getFileName() : null),
+                    convertFileName(location.getFileName()),
                     inlining.getMethod().getClassName(),
                     inlining.getMethod().getName(),
-                    location != null ? location.getLine() : 0));
+                    location.getLine()));
             while (inlining != null) {
                 MethodReference method = inlining.getParent() != null
                         ? inlining.getParent().getMethod()
diff --git a/core/src/main/java/org/teavm/model/lowlevel/Characteristics.java b/core/src/main/java/org/teavm/model/lowlevel/Characteristics.java
index 21fd39844..002e0d5fe 100644
--- a/core/src/main/java/org/teavm/model/lowlevel/Characteristics.java
+++ b/core/src/main/java/org/teavm/model/lowlevel/Characteristics.java
@@ -107,6 +107,6 @@ public class Characteristics {
         if (cls.getAnnotations().get(Unmanaged.class.getName()) != null) {
             return false;
         }
-        return method == null || method.getAnnotations().get(Unmanaged.class.getName()) == null;
+        return method.getAnnotations().get(Unmanaged.class.getName()) == null;
     }
 }
diff --git a/core/src/main/java/org/teavm/model/lowlevel/ExportDependencyListener.java b/core/src/main/java/org/teavm/model/lowlevel/ExportDependencyListener.java
index 0033f5dfb..e21b6c196 100644
--- a/core/src/main/java/org/teavm/model/lowlevel/ExportDependencyListener.java
+++ b/core/src/main/java/org/teavm/model/lowlevel/ExportDependencyListener.java
@@ -249,7 +249,7 @@ public class ExportDependencyListener extends AbstractDependencyListener {
         return true;
     }
 
-    class FunctionGetFinder extends AbstractInstructionReader {
+    static class FunctionGetFinder extends AbstractInstructionReader {
         DisjointSet variableClasses = new DisjointSet();
         String[] stringConstants;
         ValueType[] classConstants;
diff --git a/core/src/main/java/org/teavm/model/text/ListingLexer.java b/core/src/main/java/org/teavm/model/text/ListingLexer.java
index d67f7c667..d7d4b78bf 100644
--- a/core/src/main/java/org/teavm/model/text/ListingLexer.java
+++ b/core/src/main/java/org/teavm/model/text/ListingLexer.java
@@ -154,7 +154,7 @@ class ListingLexer {
                 break;
             case '*':
                 nextChar();
-                token = ListingToken.SUBTRACT;
+                token = ListingToken.MULTIPLY;
                 break;
             case '/':
                 nextChar();
diff --git a/core/src/main/java/org/teavm/model/transformation/BoundCheckInsertion.java b/core/src/main/java/org/teavm/model/transformation/BoundCheckInsertion.java
index 37f176df4..bfc089105 100644
--- a/core/src/main/java/org/teavm/model/transformation/BoundCheckInsertion.java
+++ b/core/src/main/java/org/teavm/model/transformation/BoundCheckInsertion.java
@@ -375,10 +375,8 @@ public class BoundCheckInsertion {
                 }
             }
 
-            if (lower) {
-                if ((isConstant[index] && constantValue[index] >= 0) || nonNegative[index]) {
-                    lower = false;
-                }
+            if ((isConstant[index] && constantValue[index] >= 0) || nonNegative[index]) {
+                lower = false;
             }
 
             if (upper) {
diff --git a/core/src/main/java/org/teavm/parsing/ProgramParser.java b/core/src/main/java/org/teavm/parsing/ProgramParser.java
index 85da08443..6349e35e7 100644
--- a/core/src/main/java/org/teavm/parsing/ProgramParser.java
+++ b/core/src/main/java/org/teavm/parsing/ProgramParser.java
@@ -878,13 +878,7 @@ public class ProgramParser {
         @Override
         public void visitIntInsn(int opcode, int operand) {
             switch (opcode) {
-                case Opcodes.BIPUSH: {
-                    IntegerConstantInstruction insn = new IntegerConstantInstruction();
-                    insn.setConstant(operand);
-                    insn.setReceiver(getVariable(pushSingle()));
-                    addInstruction(insn);
-                    break;
-                }
+                case Opcodes.BIPUSH:
                 case Opcodes.SIPUSH: {
                     IntegerConstantInstruction insn = new IntegerConstantInstruction();
                     insn.setConstant(operand);
diff --git a/core/src/main/java/org/teavm/runtime/ExceptionHandling.java b/core/src/main/java/org/teavm/runtime/ExceptionHandling.java
index cadba5430..9832660fe 100644
--- a/core/src/main/java/org/teavm/runtime/ExceptionHandling.java
+++ b/core/src/main/java/org/teavm/runtime/ExceptionHandling.java
@@ -53,7 +53,7 @@ public final class ExceptionHandling {
                 CallSite callSite = findCallSiteById(callSiteId, stackFrame);
                 CallSiteLocation location = callSite.location;
                 while (location != null) {
-                    MethodLocation methodLocation = location != null ? location.method : null;
+                    MethodLocation methodLocation = location.method;
 
                     Console.printString("    at ");
                     if (methodLocation.className == null || methodLocation.methodName == null) {
@@ -184,7 +184,7 @@ public final class ExceptionHandling {
             if (isObfuscated()) {
                 target[index++] = new StackTraceElement("Obfuscated", "obfuscated", "Obfuscated.java", callSiteId);
             } else if (location == null) {
-                target[index++] = new StackTraceElement("", "", null, location.lineNumber);
+                target[index++] = new StackTraceElement("", "", null, -1);
             } else {
                 while (location != null) {
                     MethodLocation methodLocation = location.method;
diff --git a/html4j/src/main/java/org/teavm/html4j/JavaScriptBodyDependency.java b/html4j/src/main/java/org/teavm/html4j/JavaScriptBodyDependency.java
index e3306960e..1ae6c6e26 100644
--- a/html4j/src/main/java/org/teavm/html4j/JavaScriptBodyDependency.java
+++ b/html4j/src/main/java/org/teavm/html4j/JavaScriptBodyDependency.java
@@ -157,6 +157,7 @@ public class JavaScriptBodyDependency extends AbstractDependencyListener {
             if (reader == null) {
                 agent.getDiagnostics().error(new CallLocation(caller.getReference()), "Can't resolve method {{m0}}",
                         methodRef);
+                return;
             }
 
             methodRef = reader.getReference();
diff --git a/html4j/src/main/java/org/teavm/html4j/JavaScriptResourceInterceptor.java b/html4j/src/main/java/org/teavm/html4j/JavaScriptResourceInterceptor.java
index 65b4661c2..165e024ed 100644
--- a/html4j/src/main/java/org/teavm/html4j/JavaScriptResourceInterceptor.java
+++ b/html4j/src/main/java/org/teavm/html4j/JavaScriptResourceInterceptor.java
@@ -38,8 +38,9 @@ public class JavaScriptResourceInterceptor extends AbstractRendererListener {
                 continue;
             }
             String path = annot.getValue("value").getString();
-            String packageName = className.substring(0, className.lastIndexOf('.'));
-            String resourceName = packageName.replace('.', '/') + "/" + path;
+            int packageIndex = className.lastIndexOf('.');
+            String packageName = packageIndex >= 0 ? className.substring(0, packageIndex) : "";
+            String resourceName = packageName.isEmpty() ? path : packageName.replace('.', '/') + "/" + path;
             try (InputStream input = manager.getClassLoader().getResourceAsStream(resourceName)) {
                 if (input == null) {
                     throw new RenderingException("Error processing JavaScriptResource annotation on class "
diff --git a/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java b/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
index be89a2651..104fb999c 100644
--- a/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
+++ b/jso/impl/src/main/java/org/teavm/jso/impl/JSClassProcessor.java
@@ -786,7 +786,7 @@ class JSClassProcessor {
 
     private boolean isProperSetIndexer(MethodDescriptor desc) {
         return desc.parameterCount() == 2 && typeHelper.isSupportedType(desc.parameterType(0))
-                && typeHelper.isSupportedType(desc.parameterType(0)) && desc.getResultType() == ValueType.VOID;
+                && typeHelper.isSupportedType(desc.parameterType(1)) && desc.getResultType() == ValueType.VOID;
     }
 
     private static String cutPrefix(String name, int prefixLength) {
diff --git a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
index 181b61806..a9b25e558 100644
--- a/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
+++ b/metaprogramming/impl/src/main/java/org/teavm/metaprogramming/impl/MetaprogrammingImpl.java
@@ -207,8 +207,7 @@ public final class MetaprogrammingImpl {
             return null;
         }
         ReflectMethod method = new ReflectMethodImpl(cls, methodReader);
-        return new SourceLocation(method, location != null ? location.getFileName() : null,
-                location != null ? location.getLine() : null);
+        return new SourceLocation(method, location.getFileName(), location.getLine());
     }
 
     @SuppressWarnings("WeakerAccess")
diff --git a/tests/src/test/java/org/teavm/classlib/java/util/CalendarTest.java b/tests/src/test/java/org/teavm/classlib/java/util/CalendarTest.java
index b8d485d59..061a947a9 100644
--- a/tests/src/test/java/org/teavm/classlib/java/util/CalendarTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/util/CalendarTest.java
@@ -603,9 +603,6 @@ public class CalendarTest {
         }
     }
 
-    /**
-     * @tests java.util.Calendar#isSet(int)
-     */
     @Test
     public void test_isSet() {
         Calendar calendar = Calendar.getInstance();
@@ -615,10 +612,6 @@ public class CalendarTest {
         }
     }
 
-    /**
-     * @tests java.util.Calendar#getInstance(Locale)
-     * @tests java.util.Calendar#getInstance(TimeZone, Locale)
-     */
     @Test
     public void test_getInstance() {
         // test getInstance(Locale)
@@ -640,9 +633,6 @@ public class CalendarTest {
                 .getID(), estCalendar.getTimeZone().getID());
     }
 
-    /**
-     * @tests java.util.Calendar#internalGet(int)
-     */
     @Test
     public void test_internalGet() {
         MockGregorianCalendar c = new MockGregorianCalendar();
@@ -650,18 +640,12 @@ public class CalendarTest {
         assertEquals(0, c.internal_get(Calendar.YEAR));
     }
 
-    /**
-     * @tests java.util.Calendar#hashCode()
-     */
     @Test
     public void test_hashcode() {
         Calendar calendar = Calendar.getInstance(Locale.JAPAN);
         assertTrue(calendar.hashCode() == calendar.hashCode());
     }
 
-    /**
-     * @tests java.util.Calendar#roll(int, int)
-     */
     @Test
     public void test_roll() {
         Calendar calendar = Calendar.getInstance();
diff --git a/tools/chrome-rdp/src/main/java/org/teavm/chromerdp/ChromeRDPRunner.java b/tools/chrome-rdp/src/main/java/org/teavm/chromerdp/ChromeRDPRunner.java
index a7b025b04..317aef323 100644
--- a/tools/chrome-rdp/src/main/java/org/teavm/chromerdp/ChromeRDPRunner.java
+++ b/tools/chrome-rdp/src/main/java/org/teavm/chromerdp/ChromeRDPRunner.java
@@ -234,7 +234,7 @@ public final class ChromeRDPRunner {
     private Command resumeCommand = args -> debugger.resume();
 
     private Command breakpointCommand = args -> {
-        if (args.length != 3 && args.length != 3) {
+        if (args.length < 2 || args.length > 4) {
             System.out.println("Expected 2 arguments");
             return Promise.VOID;
         }
diff --git a/tools/cli/src/main/java/org/teavm/cli/TeaVMCBuilderRunner.java b/tools/cli/src/main/java/org/teavm/cli/TeaVMCBuilderRunner.java
index 06ae2129d..0b04e00fa 100644
--- a/tools/cli/src/main/java/org/teavm/cli/TeaVMCBuilderRunner.java
+++ b/tools/cli/src/main/java/org/teavm/cli/TeaVMCBuilderRunner.java
@@ -135,7 +135,7 @@ public class TeaVMCBuilderRunner {
         if (args.length != 1) {
             System.err.println("Unexpected arguments");
             printUsage();
-        } else if (args.length == 1) {
+        } else {
             builder.setMainClass(args[0]);
         }
     }
diff --git a/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java b/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
index 5f89b524f..ec5a749dc 100644
--- a/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
+++ b/tools/cli/src/main/java/org/teavm/cli/TeaVMDevServerRunner.java
@@ -35,7 +35,7 @@ public final class TeaVMDevServerRunner {
         setupOptions();
     }
 
-    @SuppressWarnings("static-access")
+    @SuppressWarnings("AccessStaticViaInstance")
     private static void setupOptions() {
         options.addOption(OptionBuilder
                 .withArgName("directory")
@@ -150,7 +150,7 @@ public final class TeaVMDevServerRunner {
         if (args.length != 1) {
             System.err.println("Unexpected arguments");
             printUsage();
-        } else if (args.length == 1) {
+        } else {
             devServer.setMainClass(args[0]);
         }
     }
diff --git a/tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java b/tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java
index 6e9cdc3ca..e5a35aedb 100644
--- a/tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java
+++ b/tools/core/src/main/java/org/teavm/tooling/TeaVMTool.java
@@ -366,7 +366,7 @@ public class TeaVMTool {
                         fileTable, variableTable, classSource, innerClassSource);
                 programCache = new DiskProgramCache(cacheDirectory, referenceCache, symbolTable, fileTable,
                         variableTable);
-                if (incremental && targetType == TeaVMTargetType.JAVASCRIPT) {
+                if (targetType == TeaVMTargetType.JAVASCRIPT) {
                     astCache = new DiskMethodNodeCache(cacheDirectory, referenceCache, symbolTable, fileTable,
                             variableTable);
                     javaScriptTarget.setAstCache(astCache);
diff --git a/tools/devserver/src/main/java/org/teavm/devserver/deobfuscate/Deobfuscator.java b/tools/devserver/src/main/java/org/teavm/devserver/deobfuscate/Deobfuscator.java
index 86462efc6..1bbe44924 100644
--- a/tools/devserver/src/main/java/org/teavm/devserver/deobfuscate/Deobfuscator.java
+++ b/tools/devserver/src/main/java/org/teavm/devserver/deobfuscate/Deobfuscator.java
@@ -118,6 +118,7 @@ public final class Deobfuscator {
             if (location != null) {
                 frame.setLineNumber(location.getLine());
             }
+            result.add(frame);
         }
 
         if (result.isEmpty()) {
diff --git a/tools/junit/src/main/java/org/teavm/junit/TeaVMTestRunner.java b/tools/junit/src/main/java/org/teavm/junit/TeaVMTestRunner.java
index babb0dcdf..0527e0c70 100644
--- a/tools/junit/src/main/java/org/teavm/junit/TeaVMTestRunner.java
+++ b/tools/junit/src/main/java/org/teavm/junit/TeaVMTestRunner.java
@@ -130,7 +130,6 @@ public class TeaVMTestRunner extends Runner implements Filterable {
     static {
         for (RunKind kind : RunKind.values()) {
             runners.put(kind, new RunnerKindInfo());
-            runners.put(kind, new RunnerKindInfo());
         }
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
             synchronized (TeaVMTestRunner.class) {