1 files changed, 109 insertions, 0 deletions
diff --git a/deps/v8/build/android/bytecode/java/org/chromium/bytecode/AssertionEnablerClassAdapter.java b/deps/v8/build/android/bytecode/java/org/chromium/bytecode/AssertionEnablerClassAdapter.java
new file mode 100644
index 0000000000..0a903a60f9
--- /dev/null
+++ b/deps/v8/build/android/bytecode/java/org/chromium/bytecode/AssertionEnablerClassAdapter.java
@@ -0,0 +1,109 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.bytecode;
+
+import static org.chromium.bytecode.TypeUtils.ASSERTION_ERROR;
+import static org.chromium.bytecode.TypeUtils.BUILD_HOOKS;
+import static org.chromium.bytecode.TypeUtils.VOID;
+
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+/**
+ * An ClassVisitor for replacing Java ASSERT statements with a function by modifying Java bytecode.
+ *
+ * We do this in two steps, first step is to enable assert.
+ * Following bytecode is generated for each class with ASSERT statements:
+ * 0: ldc #8 // class CLASSNAME
+ * 2: invokevirtual #9 // Method java/lang/Class.desiredAssertionStatus:()Z
+ * 5: ifne 12
+ * 8: iconst_1
+ * 9: goto 13
+ * 12: iconst_0
+ * 13: putstatic #2 // Field $assertionsDisabled:Z
+ * Replaces line #13 to the following:
+ * 13: pop
+ * Consequently, $assertionsDisabled is assigned the default value FALSE.
+ * This is done in the first if statement in overridden visitFieldInsn. We do this per per-assert.
+ *
+ * Second step is to replace assert statement with a function:
+ * The followed instructions are generated by a java assert statement:
+ * getstatic     #3     // Field $assertionsDisabled:Z
+ * ifne          118    // Jump to instruction as if assertion if not enabled
+ * ...
+ * ifne          19
+ * new           #4     // class java/lang/AssertionError
+ * dup
+ * ldc           #5     // String (don't have this line if no assert message given)
+ * invokespecial #6     // Method java/lang/AssertionError.
+ * athrow
+ * Replace athrow with:
+ * invokestatic  #7     // Method org/chromium/base/JavaExceptionReporter.assertFailureHandler
+ * goto          118
+ * JavaExceptionReporter.assertFailureHandler is a function that handles the AssertionError,
+ * 118 is the instruction to execute as if assertion if not enabled.
+ */
+class AssertionEnablerClassAdapter extends ClassVisitor {
+    AssertionEnablerClassAdapter(ClassVisitor visitor) {
+        super(Opcodes.ASM5, visitor);
+    }
+
+    @Override
+    public MethodVisitor visitMethod(final int access, final String name, String desc,
+            String signature, String[] exceptions) {
+        return new RewriteAssertMethodVisitor(
+                Opcodes.ASM5, super.visitMethod(access, name, desc, signature, exceptions));
+    }
+
+    static class RewriteAssertMethodVisitor extends MethodVisitor {
+        static final String ASSERTION_DISABLED_NAME = "$assertionsDisabled";
+        static final String INSERT_INSTRUCTION_NAME = "assertFailureHandler";
+        static final String INSERT_INSTRUCTION_DESC =
+                TypeUtils.getMethodDescriptor(VOID, ASSERTION_ERROR);
+        static final boolean INSERT_INSTRUCTION_ITF = false;
+
+        boolean mStartLoadingAssert;
+        Label mGotoLabel;
+
+        public RewriteAssertMethodVisitor(int api, MethodVisitor mv) {
+            super(api, mv);
+        }
+
+        @Override
+        public void visitFieldInsn(int opcode, String owner, String name, String desc) {
+            if (opcode == Opcodes.PUTSTATIC && name.equals(ASSERTION_DISABLED_NAME)) {
+                super.visitInsn(Opcodes.POP); // enable assert
+            } else if (opcode == Opcodes.GETSTATIC && name.equals(ASSERTION_DISABLED_NAME)) {
+                mStartLoadingAssert = true;
+                super.visitFieldInsn(opcode, owner, name, desc);
+            } else {
+                super.visitFieldInsn(opcode, owner, name, desc);
+            }
+        }
+
+        @Override
+        public void visitJumpInsn(int opcode, Label label) {
+            if (mStartLoadingAssert && opcode == Opcodes.IFNE && mGotoLabel == null) {
+                mGotoLabel = label;
+            }
+            super.visitJumpInsn(opcode, label);
+        }
+
+        @Override
+        public void visitInsn(int opcode) {
+            if (!mStartLoadingAssert || opcode != Opcodes.ATHROW) {
+                super.visitInsn(opcode);
+            } else {
+                super.visitMethodInsn(Opcodes.INVOKESTATIC, BUILD_HOOKS, INSERT_INSTRUCTION_NAME,
+                        INSERT_INSTRUCTION_DESC, INSERT_INSTRUCTION_ITF);
+                super.visitJumpInsn(Opcodes.GOTO, mGotoLabel);
+                mStartLoadingAssert = false;
+                mGotoLabel = null;
+            }
+        }
+    }
+}
+\ No newline at end of file