8315771: [JVMCI] Resolution of bootstrap methods with int[] static arguments

Reviewed-by: dnsimon, psandoz

Author: Zeavee

src/hotspot/share/jvmci/jvmciCompilerToVM.cpp

@@ -771,9 +771,11 @@ C2V_VMENTRY_NULL(jobjectArray, resolveBootstrapMethod, (JNIEnv* env, jobject, AR
   }
   // Get the indy entry based on CP index
   int indy_index = -1;
-  for (int i = 0; i < cp->resolved_indy_entries_length(); i++) {
-    if (cp->resolved_indy_entry_at(i)->constant_pool_index() == index) {
-      indy_index = i;
+  if (is_indy) {
+    for (int i = 0; i < cp->resolved_indy_entries_length(); i++) {
+      if (cp->resolved_indy_entry_at(i)->constant_pool_index() == index) {
+        indy_index = i;
+      }
     }
   }
   // Resolve the bootstrap specifier, its name, type, and static arguments
@@ -839,6 +841,11 @@ C2V_VMENTRY_NULL(jobjectArray, resolveBootstrapMethod, (JNIEnv* env, jobject, AR
   return JVMCIENV->get_jobjectArray(bsmi);
 C2V_END
 
+C2V_VMENTRY_0(jint, bootstrapArgumentIndexAt, (JNIEnv* env, jobject, ARGUMENT_PAIR(cp), jint cpi, jint index))
+  constantPoolHandle cp(THREAD, UNPACK_PAIR(ConstantPool, cp));
+  return cp->bootstrap_argument_index_at(cpi, index);
+C2V_END
+
 C2V_VMENTRY_0(jint, lookupNameAndTypeRefIndexInPool, (JNIEnv* env, jobject, ARGUMENT_PAIR(cp), jint index, jint opcode))
   constantPoolHandle cp(THREAD, UNPACK_PAIR(ConstantPool, cp));
   return cp->name_and_type_ref_index_at(index, (Bytecodes::Code)opcode);
@@ -3177,6 +3184,7 @@ JNINativeMethod CompilerToVM::methods[] = {
   {CC "lookupConstantInPool",                         CC "(" HS_CONSTANT_POOL2 "IZ)" JAVACONSTANT,                                          FN_PTR(lookupConstantInPool)},
   {CC "constantPoolRemapInstructionOperandFromCache", CC "(" HS_CONSTANT_POOL2 "I)I",                                                       FN_PTR(constantPoolRemapInstructionOperandFromCache)},
   {CC "resolveBootstrapMethod",                       CC "(" HS_CONSTANT_POOL2 "I)[" OBJECT,                                                FN_PTR(resolveBootstrapMethod)},
+  {CC "bootstrapArgumentIndexAt",                     CC "(" HS_CONSTANT_POOL2 "II)I",                                                      FN_PTR(bootstrapArgumentIndexAt)},
   {CC "getUncachedStringInPool",                      CC "(" HS_CONSTANT_POOL2 "I)" JAVACONSTANT,                                           FN_PTR(getUncachedStringInPool)},
   {CC "resolveTypeInPool",                            CC "(" HS_CONSTANT_POOL2 "I)" HS_KLASS,                                               FN_PTR(resolveTypeInPool)},
   {CC "resolveFieldInPool",                           CC "(" HS_CONSTANT_POOL2 "I" HS_METHOD2 "B[I)" HS_KLASS,                              FN_PTR(resolveFieldInPool)},

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/CompilerToVM.java

@@ -483,6 +483,28 @@ Object[] resolveBootstrapMethod(HotSpotConstantPool constantPool, int cpi) {
 
     private native Object[] resolveBootstrapMethod(HotSpotConstantPool constantPool, long constantPoolPointer, int cpi);
 
+    /**
+     * Gets the constant pool index of a static argument of a {@code CONSTANT_Dynamic_info} or
+     * @{code CONSTANT_InvokeDynamic_info} entry. Used when the list of static arguments in the
+     * {@link BootstrapMethodInvocation} is a {@code List<PrimitiveConstant>} of the form
+     * {{@code arg_count}, {@code pool_index}}, meaning the arguments are not already resolved and that
+     * the JDK has to lookup the arguments when they are needed. The {@code cpi} corresponds to
+     * {@code pool_index} and the {@code index} has to be smaller than {@code arg_count}.
+     *
+     * The behavior of this method is undefined if {@code cpi} does not denote an entry representing
+     * a {@code CONSTANT_Dynamic_info} or a @{code CONSTANT_InvokeDynamic_info}, or if the index
+     * is out of bounds.
+     *
+     * @param cpi the index of a {@code CONSTANT_Dynamic_info} or @{code CONSTANT_InvokeDynamic_info} entry
+     * @param index the index of the static argument in the list of static arguments
+     * @return the constant pool index associated with the static argument
+     */
+    int bootstrapArgumentIndexAt(HotSpotConstantPool constantPool, int cpi, int index) {
+        return bootstrapArgumentIndexAt(constantPool, constantPool.getConstantPoolPointer(), cpi, index);
+    }
+
+    private native int bootstrapArgumentIndexAt(HotSpotConstantPool constantPool, long constantPoolPointer, int cpi, int index);
+
     /**
      * If {@code cpi} denotes an entry representing a signature polymorphic method ({@jvms 2.9}),
      * this method ensures that the type referenced by the entry is loaded and initialized. It

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotConstantPool.java

@@ -27,6 +27,8 @@
 import static jdk.vm.ci.hotspot.HotSpotVMConfig.config;
 import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
 
+import java.util.AbstractList;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -38,6 +40,7 @@
 import jdk.vm.ci.meta.JavaField;
 import jdk.vm.ci.meta.JavaMethod;
 import jdk.vm.ci.meta.JavaType;
+import jdk.vm.ci.meta.PrimitiveConstant;
 import jdk.vm.ci.meta.ResolvedJavaMethod;
 import jdk.vm.ci.meta.ResolvedJavaType;
 import jdk.vm.ci.meta.Signature;
@@ -504,6 +507,60 @@ private int flags() {
         return UNSAFE.getInt(getConstantPoolPointer() + config().constantPoolFlagsOffset);
     }
 
+    /**
+     * Represents a list of static arguments from a {@link BootstrapMethodInvocation} of the form
+     * {{@code arg_count}, {@code pool_index}}, meaning the arguments are not already resolved
+     * and that the JDK has to lookup the arguments when they are needed. The {@code bssIndex}
+     * corresponds to {@code pool_index} and the {@code size} corresponds to {@code arg_count}.
+     */
+    static class CachedBSMArgs extends AbstractList<JavaConstant> {
+        private final JavaConstant[] cache;
+        private final HotSpotConstantPool cp;
+        private final int bssIndex;
+
+        CachedBSMArgs(HotSpotConstantPool cp, int bssIndex, int size) {
+            this.cp = cp;
+            this.bssIndex = bssIndex;
+            this.cache = new JavaConstant[size];
+        }
+
+        /**
+         * Lazily resolves and caches the argument at the given index and returns it. The method
+         * {@link CompilerToVM#bootstrapArgumentIndexAt} is used to obtain the constant pool
+         * index of the entry and the method {@link ConstantPool#lookupConstant} is used to
+         * resolve it. If the resolution failed, the index is returned as a
+         * {@link PrimitiveConstant}.
+         *
+         * @param index index of the element to return
+         * @return A {@link JavaConstant} corresponding to the static argument requested. A return
+         * value of type {@link PrimitiveConstant} represents an unresolved constant pool entry
+         */
+        @Override
+        public JavaConstant get(int index) {
+            JavaConstant res = cache[index];
+            if (res == null) {
+                int argCpi = compilerToVM().bootstrapArgumentIndexAt(cp, bssIndex, index);
+                Object object = cp.lookupConstant(argCpi, false);
+                if (object instanceof PrimitiveConstant primitiveConstant) {
+                    res = runtime().getReflection().boxPrimitive(primitiveConstant);
+                } else if (object instanceof JavaConstant javaConstant) {
+                    res = javaConstant;
+                } else if (object instanceof JavaType type) {
+                    res = runtime().getReflection().forObject(type);
+                } else {
+                    res = JavaConstant.forInt(argCpi);
+                }
+                cache[index] = res;
+            }
+            return res;
+        }
+
+        @Override
+        public int size() {
+            return cache.length;
+        }
+    }
+
     static class BootstrapMethodInvocationImpl implements BootstrapMethodInvocation {
         private final boolean indy;
         private final ResolvedJavaMethod method;
@@ -582,8 +639,9 @@ public BootstrapMethodInvocation lookupBootstrapMethodInvocation(int index, int
                     staticArgumentsList = List.of((JavaConstant[]) staticArguments);
                 } else {
                     int[] bsciArgs = (int[]) staticArguments;
-                    String message = String.format("Resolving bootstrap static arguments for %s using BootstrapCallInfo %s not supported", method.format("%H.%n(%p)"), Arrays.toString(bsciArgs));
-                    throw new IllegalArgumentException(message);
+                    int argCount = bsciArgs[0];
+                    int bss_index = bsciArgs[1];
+                    staticArgumentsList = new CachedBSMArgs(this, bss_index, argCount);
                 }
                 return new BootstrapMethodInvocationImpl(tag.name.equals("InvokeDynamic"), method, name, type, staticArgumentsList);
             default:

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/meta/ConstantPool.java

@@ -131,7 +131,7 @@ default JavaMethod lookupMethod(int cpi, int opcode) {
 
     /**
      * The details for invoking a bootstrap method associated with a {@code CONSTANT_Dynamic_info}
-     * or {@code CONSTANT_InvokeDynamic_info} pool entry .
+     * or {@code CONSTANT_InvokeDynamic_info} pool entry.
      *
      * @jvms 4.4.10 The {@code CONSTANT_Dynamic_info} and {@code CONSTANT_InvokeDynamic_info}
      *       Structures
@@ -165,6 +165,29 @@ interface BootstrapMethodInvocation {
         /**
          * Gets the static arguments with which the bootstrap method will be invoked.
          *
+         * The {@linkplain JavaConstant#getJavaKind kind} of each argument will be
+         * {@link JavaKind#Object} or {@link JavaKind#Int}. The latter represents an
+         * unresolved {@code CONSTANT_Dynamic_info} entry. To resolve this entry, the
+         * corresponding bootstrap method has to be called first:
+         *
+         * <pre>
+         * List<JavaConstant> args = bmi.getStaticArguments();
+         * List<JavaConstant> resolvedArgs = new ArrayList<>(args.size());
+         * for (JavaConstant c : args) {
+         *     JavaConstant r = c;
+         *     if (c.getJavaKind() == JavaKind.Int) {
+         *         // If needed, access corresponding BootstrapMethodInvocation using
+         *         // cp.lookupBootstrapMethodInvocation(pc.asInt(), -1)
+         *         r = cp.lookupConstant(c.asInt(), true);
+         *     } else {
+         *         assert c.getJavaKind() == JavaKind.Object;
+         *     }
+         *     resolvedArgs.append(r);
+         * }
+         * </pre>
+         *
+         * The other types of entries are already resolved an can be used directly.
+         *
          * @jvms 5.4.3.6
          */
         List<JavaConstant> getStaticArguments();
@@ -182,8 +205,6 @@ interface BootstrapMethodInvocation {
      *            {@code index} was not decoded from a bytecode stream
      * @return the bootstrap method invocation details or {@code null} if the entry specified by {@code index}
      *         is not a {@code CONSTANT_Dynamic_info} or @{code CONSTANT_InvokeDynamic_info}
-     * @throws IllegalArgumentException if the bootstrap method invocation makes use of
-     *             {@code java.lang.invoke.BootstrapCallInfo}
      * @jvms 4.7.23 The {@code BootstrapMethods} Attribute
      */
     default BootstrapMethodInvocation lookupBootstrapMethodInvocation(int index, int opcode) {