Crema: fix invokedynamic patching the wrong cpi

Author: gilles-duboscq

substratevm/src/com.oracle.svm.interpreter.metadata/src/com/oracle/svm/interpreter/metadata/BytecodeStream.java

@@ -260,16 +260,6 @@ public static char readCPI2(byte[] code, int curBCI) {
         return (char) ByteUtils.beU2(code, curBCI + 1);
     }
 
-    /**
-     * Reads a 2-byte constant pool index for the current instruction, reading each byte with
-     * volatile semantics. Note that this does not read the 2 bytes atomically.
-     *
-     * @return the constant pool index
-     */
-    public static char readCPI2Volatile(byte[] code, int curBCI) {
-        return (char) (((ByteUtils.volatileBeU1(code, curBCI + 1) & 0xff) << 8) | (ByteUtils.volatileBeU1(code, curBCI + 1 + 1) & 0xff));
-    }
-
     /**
      * Reads a constant pool index for the current instruction.
      *
@@ -371,25 +361,20 @@ private static String unknownVariableLengthBytecodeMessage(int opcode) {
         return "unknown variable-length bytecode: " + opcode;
     }
 
-    @Platforms(Platform.HOSTED_ONLY.class)
-    public static void patchAppendixCPI(byte[] code, int curBCI, int appendixCPI) {
-        int opcode = opcode(code, curBCI);
-        switch (opcode) {
-            case INVOKEDYNAMIC:
-                code[curBCI + 3] = (byte) ((appendixCPI >> 8) & 0xFF);
-                code[curBCI + 4] = (byte) (appendixCPI & 0xFF);
-                break;
-            default:
-                throw VMError.shouldNotReachHereAtRuntime();
-        }
+    /**
+     * Reads the 2-byte extra CPI for the current invokedynamic instruction, reading each byte with
+     * volatile semantics. Note that this does not read the 2 bytes atomically.
+     */
+    public static char readIndyExtraCPIVolatile(byte[] code, int curBCI) {
+        return (char) ((ByteUtils.volatileBeU1(code, curBCI + 3) << 8) | ByteUtils.volatileBeU1(code, curBCI + 4));
     }
 
     public static void patchIndyExtraCPI(byte[] code, int curBCI, int extraCPI) {
         int opcode = opcode(code, curBCI);
         switch (opcode) {
             case INVOKEDYNAMIC:
-                code[curBCI + 1] = (byte) ((extraCPI >> 8) & 0xFF);
-                code[curBCI + 2] = (byte) (extraCPI & 0xFF);
+                code[curBCI + 3] = (byte) ((extraCPI >> 8) & 0xFF);
+                code[curBCI + 4] = (byte) (extraCPI & 0xFF);
                 break;
             default:
                 throw VMError.shouldNotReachHereAtRuntime();

substratevm/src/com.oracle.svm.interpreter/src/com/oracle/svm/interpreter/BuildTimeConstantPool.java

@@ -448,7 +448,7 @@ public void hydrate(InterpreterResolvedObjectType type) {
                                 // in the CP.
                                 newAppendixCPI = appendixConstant(JavaConstant.NULL_POINTER);
                             }
-                            BytecodeStream.patchAppendixCPI(code, bci, newAppendixCPI);
+                            BytecodeStream.patchIndyExtraCPI(code, bci, newAppendixCPI);
                         }
 
                         BytecodeStream.patchCPI(code, bci, newCPI);

substratevm/src/com.oracle.svm.interpreter/src/com/oracle/svm/interpreter/Interpreter.java

@@ -1401,7 +1401,8 @@ private static int invoke(InterpreterFrame callerFrame, InterpreterResolvedJavaM
                         throw SemanticJavaException.raise(e);
                     }
                     BytecodeStream.patchIndyExtraCPI(code, curBCI, extraCPI);
-                    assert BytecodeStream.readCPI2Volatile(code, curBCI) == extraCPI;
+                    assert BytecodeStream.readIndyExtraCPIVolatile(code, curBCI) == extraCPI;
+                    assert BytecodeStream.readCPI2(code, curBCI) == indyCPI;
                 }
                 CallSiteLink link = invokeDynamicConstant.getCallSiteLink(extraCPI);
                 while (!link.matchesCallSite(method, curBCI)) {
@@ -1411,7 +1412,7 @@ private static int invoke(InterpreterFrame callerFrame, InterpreterResolvedJavaM
                      * still safe to use in `getCallSiteLink`. `matchesCallSite` ensures we have the
                      * full extraCPI.
                      */
-                    extraCPI = BytecodeStream.readCPI2Volatile(code, curBCI);
+                    extraCPI = BytecodeStream.readIndyExtraCPIVolatile(code, curBCI);
                     link = invokeDynamicConstant.getCallSiteLink(extraCPI);
                 }
                 if (link instanceof SuccessfulCallSiteLink successfulCallSiteLink) {

substratevm/src/com.oracle.svm.interpreter/src/com/oracle/svm/interpreter/classfile/ClassFile.java

@@ -1000,7 +1000,7 @@ private byte[] recomputeConstantPoolIndices(ResolvedJavaMethod method) {
                     // The VM already provides the resolved bootstrap method and appendix.
                     // Investigate how to persist the appendix (arbitrary object) on the constant pool.
                     BytecodeStream.patchCPI(code, bci, 0);
-                    BytecodeStream.patchAppendixCPI(code, bci, 0);
+                    BytecodeStream.patchIndyExtraCPI(code, bci, 0);
                     break;
             }
             // @formatter:on