Mercurial > hg > truffle
view src/share/vm/interpreter/rewriter.cpp @ 15368:44dcd95a4bf6
fix NPE in BenchmarkCounters, remove exclusion based on prefix
author | Lukas Stadler <lukas.stadler@oracle.com> |
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date | Thu, 24 Apr 2014 17:30:48 +0200 |
parents | 4ca6dc0799b6 |
children | 52b4284cb496 |
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/* * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "interpreter/bytecodes.hpp" #include "interpreter/interpreter.hpp" #include "interpreter/rewriter.hpp" #include "memory/gcLocker.hpp" #include "memory/resourceArea.hpp" #include "oops/generateOopMap.hpp" #include "prims/methodHandles.hpp" // Computes a CPC map (new_index -> original_index) for constant pool entries // that are referred to by the interpreter at runtime via the constant pool cache. // Also computes a CP map (original_index -> new_index). // Marks entries in CP which require additional processing. void Rewriter::compute_index_maps() { const int length = _pool->length(); init_maps(length); bool saw_mh_symbol = false; for (int i = 0; i < length; i++) { int tag = _pool->tag_at(i).value(); switch (tag) { case JVM_CONSTANT_InterfaceMethodref: case JVM_CONSTANT_Fieldref : // fall through case JVM_CONSTANT_Methodref : // fall through add_cp_cache_entry(i); break; case JVM_CONSTANT_String: case JVM_CONSTANT_MethodHandle : // fall through case JVM_CONSTANT_MethodType : // fall through add_resolved_references_entry(i); break; case JVM_CONSTANT_Utf8: if (_pool->symbol_at(i) == vmSymbols::java_lang_invoke_MethodHandle()) saw_mh_symbol = true; break; } } // Record limits of resolved reference map for constant pool cache indices record_map_limits(); guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1), "all cp cache indexes fit in a u2"); if (saw_mh_symbol) _method_handle_invokers.initialize(length, (int)0); } // Unrewrite the bytecodes if an error occurs. void Rewriter::restore_bytecodes() { int len = _methods->length(); bool invokespecial_error = false; for (int i = len-1; i >= 0; i--) { Method* method = _methods->at(i); scan_method(method, true, &invokespecial_error); assert(!invokespecial_error, "reversing should not get an invokespecial error"); } } // Creates a constant pool cache given a CPC map void Rewriter::make_constant_pool_cache(TRAPS) { ClassLoaderData* loader_data = _pool->pool_holder()->class_loader_data(); ConstantPoolCache* cache = ConstantPoolCache::allocate(loader_data, _cp_cache_map, _invokedynamic_cp_cache_map, _invokedynamic_references_map, CHECK); // initialize object cache in constant pool _pool->initialize_resolved_references(loader_data, _resolved_references_map, _resolved_reference_limit, CHECK); _pool->set_cache(cache); cache->set_constant_pool(_pool()); } // The new finalization semantics says that registration of // finalizable objects must be performed on successful return from the // Object.<init> constructor. We could implement this trivially if // <init> were never rewritten but since JVMTI allows this to occur, a // more complicated solution is required. A special return bytecode // is used only by Object.<init> to signal the finalization // registration point. Additionally local 0 must be preserved so it's // available to pass to the registration function. For simplicty we // require that local 0 is never overwritten so it's available as an // argument for registration. void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) { RawBytecodeStream bcs(method); while (!bcs.is_last_bytecode()) { Bytecodes::Code opcode = bcs.raw_next(); switch (opcode) { case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break; case Bytecodes::_istore: case Bytecodes::_lstore: case Bytecodes::_fstore: case Bytecodes::_dstore: case Bytecodes::_astore: if (bcs.get_index() != 0) continue; // fall through case Bytecodes::_istore_0: case Bytecodes::_lstore_0: case Bytecodes::_fstore_0: case Bytecodes::_dstore_0: case Bytecodes::_astore_0: THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), "can't overwrite local 0 in Object.<init>"); break; } } } // Rewrite a classfile-order CP index into a native-order CPC index. void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) { address p = bcp + offset; if (!reverse) { int cp_index = Bytes::get_Java_u2(p); int cache_index = cp_entry_to_cp_cache(cp_index); Bytes::put_native_u2(p, cache_index); if (!_method_handle_invokers.is_empty()) maybe_rewrite_invokehandle(p - 1, cp_index, cache_index, reverse); } else { int cache_index = Bytes::get_native_u2(p); int pool_index = cp_cache_entry_pool_index(cache_index); Bytes::put_Java_u2(p, pool_index); if (!_method_handle_invokers.is_empty()) maybe_rewrite_invokehandle(p - 1, pool_index, cache_index, reverse); } } // If the constant pool entry for invokespecial is InterfaceMethodref, // we need to add a separate cpCache entry for its resolution, because it is // different than the resolution for invokeinterface with InterfaceMethodref. // These cannot share cpCache entries. It's unclear if all invokespecial to // InterfaceMethodrefs would resolve to the same thing so a new cpCache entry // is created for each one. This was added with lambda. void Rewriter::rewrite_invokespecial(address bcp, int offset, bool reverse, bool* invokespecial_error) { address p = bcp + offset; if (!reverse) { int cp_index = Bytes::get_Java_u2(p); if (_pool->tag_at(cp_index).is_interface_method()) { int cache_index = add_invokespecial_cp_cache_entry(cp_index); if (cache_index != (int)(jushort) cache_index) { *invokespecial_error = true; } Bytes::put_native_u2(p, cache_index); } else { rewrite_member_reference(bcp, offset, reverse); } } else { rewrite_member_reference(bcp, offset, reverse); } } // Adjust the invocation bytecode for a signature-polymorphic method (MethodHandle.invoke, etc.) void Rewriter::maybe_rewrite_invokehandle(address opc, int cp_index, int cache_index, bool reverse) { if (!reverse) { if ((*opc) == (u1)Bytecodes::_invokevirtual || // allow invokespecial as an alias, although it would be very odd: (*opc) == (u1)Bytecodes::_invokespecial) { assert(_pool->tag_at(cp_index).is_method(), "wrong index"); // Determine whether this is a signature-polymorphic method. if (cp_index >= _method_handle_invokers.length()) return; int status = _method_handle_invokers[cp_index]; assert(status >= -1 && status <= 1, "oob tri-state"); if (status == 0) { if (_pool->klass_ref_at_noresolve(cp_index) == vmSymbols::java_lang_invoke_MethodHandle() && MethodHandles::is_signature_polymorphic_name(SystemDictionary::MethodHandle_klass(), _pool->name_ref_at(cp_index))) { // we may need a resolved_refs entry for the appendix add_invokedynamic_resolved_references_entries(cp_index, cache_index); status = +1; } else { status = -1; } _method_handle_invokers[cp_index] = status; } // We use a special internal bytecode for such methods (if non-static). // The basic reason for this is that such methods need an extra "appendix" argument // to transmit the call site's intended call type. if (status > 0) { (*opc) = (u1)Bytecodes::_invokehandle; } } } else { // Do not need to look at cp_index. if ((*opc) == (u1)Bytecodes::_invokehandle) { (*opc) = (u1)Bytecodes::_invokevirtual; // Ignore corner case of original _invokespecial instruction. // This is safe because (a) the signature polymorphic method was final, and // (b) the implementation of MethodHandle will not call invokespecial on it. } } } void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) { address p = bcp + offset; assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode"); if (!reverse) { int cp_index = Bytes::get_Java_u2(p); int cache_index = add_invokedynamic_cp_cache_entry(cp_index); int resolved_index = add_invokedynamic_resolved_references_entries(cp_index, cache_index); // Replace the trailing four bytes with a CPC index for the dynamic // call site. Unlike other CPC entries, there is one per bytecode, // not just one per distinct CP entry. In other words, the // CPC-to-CP relation is many-to-one for invokedynamic entries. // This means we must use a larger index size than u2 to address // all these entries. That is the main reason invokedynamic // must have a five-byte instruction format. (Of course, other JVM // implementations can use the bytes for other purposes.) // Note: We use native_u4 format exclusively for 4-byte indexes. Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index)); // add the bcp in case we need to patch this bytecode if we also find a // invokespecial/InterfaceMethodref in the bytecode stream _patch_invokedynamic_bcps->push(p); _patch_invokedynamic_refs->push(resolved_index); } else { int cache_index = ConstantPool::decode_invokedynamic_index( Bytes::get_native_u4(p)); // We will reverse the bytecode rewriting _after_ adjusting them. // Adjust the cache index by offset to the invokedynamic entries in the // cpCache plus the delta if the invokedynamic bytecodes were adjusted. cache_index = cp_cache_delta() + _first_iteration_cp_cache_limit; int cp_index = invokedynamic_cp_cache_entry_pool_index(cache_index); assert(_pool->tag_at(cp_index).is_invoke_dynamic(), "wrong index"); // zero out 4 bytes Bytes::put_Java_u4(p, 0); Bytes::put_Java_u2(p, cp_index); } } void Rewriter::patch_invokedynamic_bytecodes() { // If the end of the cp_cache is the same as after initializing with the // cpool, nothing needs to be done. Invokedynamic bytecodes are at the // correct offsets. ie. no invokespecials added int delta = cp_cache_delta(); if (delta > 0) { int length = _patch_invokedynamic_bcps->length(); assert(length == _patch_invokedynamic_refs->length(), "lengths should match"); for (int i = 0; i < length; i++) { address p = _patch_invokedynamic_bcps->at(i); int cache_index = ConstantPool::decode_invokedynamic_index( Bytes::get_native_u4(p)); Bytes::put_native_u4(p, ConstantPool::encode_invokedynamic_index(cache_index + delta)); // invokedynamic resolved references map also points to cp cache and must // add delta to each. int resolved_index = _patch_invokedynamic_refs->at(i); for (int entry = 0; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) { assert(_invokedynamic_references_map[resolved_index+entry] == cache_index, "should be the same index"); _invokedynamic_references_map.at_put(resolved_index+entry, cache_index + delta); } } } } // Rewrite some ldc bytecodes to _fast_aldc void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide, bool reverse) { if (!reverse) { assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode"); address p = bcp + offset; int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p); constantTag tag = _pool->tag_at(cp_index).value(); if (tag.is_method_handle() || tag.is_method_type() || tag.is_string()) { int ref_index = cp_entry_to_resolved_references(cp_index); if (is_wide) { (*bcp) = Bytecodes::_fast_aldc_w; assert(ref_index == (u2)ref_index, "index overflow"); Bytes::put_native_u2(p, ref_index); } else { (*bcp) = Bytecodes::_fast_aldc; assert(ref_index == (u1)ref_index, "index overflow"); (*p) = (u1)ref_index; } } } else { Bytecodes::Code rewritten_bc = (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc); if ((*bcp) == rewritten_bc) { address p = bcp + offset; int ref_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p); int pool_index = resolved_references_entry_to_pool_index(ref_index); if (is_wide) { (*bcp) = Bytecodes::_ldc_w; assert(pool_index == (u2)pool_index, "index overflow"); Bytes::put_Java_u2(p, pool_index); } else { (*bcp) = Bytecodes::_ldc; assert(pool_index == (u1)pool_index, "index overflow"); (*p) = (u1)pool_index; } } } } // Rewrites a method given the index_map information void Rewriter::scan_method(Method* method, bool reverse, bool* invokespecial_error) { int nof_jsrs = 0; bool has_monitor_bytecodes = false; { // We cannot tolerate a GC in this block, because we've // cached the bytecodes in 'code_base'. If the Method* // moves, the bytecodes will also move. No_Safepoint_Verifier nsv; Bytecodes::Code c; // Bytecodes and their length const address code_base = method->code_base(); const int code_length = method->code_size(); int bc_length; for (int bci = 0; bci < code_length; bci += bc_length) { address bcp = code_base + bci; int prefix_length = 0; c = (Bytecodes::Code)(*bcp); // Since we have the code, see if we can get the length // directly. Some more complicated bytecodes will report // a length of zero, meaning we need to make another method // call to calculate the length. bc_length = Bytecodes::length_for(c); if (bc_length == 0) { bc_length = Bytecodes::length_at(method, bcp); // length_at will put us at the bytecode after the one modified // by 'wide'. We don't currently examine any of the bytecodes // modified by wide, but in case we do in the future... if (c == Bytecodes::_wide) { prefix_length = 1; c = (Bytecodes::Code)bcp[1]; } } assert(bc_length != 0, "impossible bytecode length"); switch (c) { case Bytecodes::_lookupswitch : { #ifndef CC_INTERP Bytecode_lookupswitch bc(method, bcp); (*bcp) = ( bc.number_of_pairs() < BinarySwitchThreshold ? Bytecodes::_fast_linearswitch : Bytecodes::_fast_binaryswitch ); #endif break; } case Bytecodes::_fast_linearswitch: case Bytecodes::_fast_binaryswitch: { #ifndef CC_INTERP (*bcp) = Bytecodes::_lookupswitch; #endif break; } case Bytecodes::_invokespecial : { rewrite_invokespecial(bcp, prefix_length+1, reverse, invokespecial_error); break; } case Bytecodes::_getstatic : // fall through case Bytecodes::_putstatic : // fall through case Bytecodes::_getfield : // fall through case Bytecodes::_putfield : // fall through case Bytecodes::_invokevirtual : // fall through case Bytecodes::_invokestatic : case Bytecodes::_invokeinterface: case Bytecodes::_invokehandle : // if reverse=true rewrite_member_reference(bcp, prefix_length+1, reverse); break; case Bytecodes::_invokedynamic: rewrite_invokedynamic(bcp, prefix_length+1, reverse); break; case Bytecodes::_ldc: case Bytecodes::_fast_aldc: // if reverse=true maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse); break; case Bytecodes::_ldc_w: case Bytecodes::_fast_aldc_w: // if reverse=true maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse); break; case Bytecodes::_jsr : // fall through case Bytecodes::_jsr_w : nof_jsrs++; break; case Bytecodes::_monitorenter : // fall through case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break; } } } // Update access flags if (has_monitor_bytecodes) { method->set_has_monitor_bytecodes(); } // The present of a jsr bytecode implies that the method might potentially // have to be rewritten, so we run the oopMapGenerator on the method if (nof_jsrs > 0) { method->set_has_jsrs(); // Second pass will revisit this method. assert(method->has_jsrs(), "didn't we just set this?"); } } // After constant pool is created, revisit methods containing jsrs. methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) { ResourceMark rm(THREAD); ResolveOopMapConflicts romc(method); methodHandle original_method = method; method = romc.do_potential_rewrite(CHECK_(methodHandle())); // Update monitor matching info. if (romc.monitor_safe()) { method->set_guaranteed_monitor_matching(); } return method; } void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) { ResourceMark rm(THREAD); Rewriter rw(klass, klass->constants(), klass->methods(), CHECK); // (That's all, folks.) } Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, Array<Method*>* methods, TRAPS) : _klass(klass), _pool(cpool), _methods(methods) { assert(_pool->cache() == NULL, "constant pool cache must not be set yet"); // determine index maps for Method* rewriting compute_index_maps(); if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) { bool did_rewrite = false; int i = _methods->length(); while (i-- > 0) { Method* method = _methods->at(i); if (method->intrinsic_id() == vmIntrinsics::_Object_init) { // rewrite the return bytecodes of Object.<init> to register the // object for finalization if needed. methodHandle m(THREAD, method); rewrite_Object_init(m, CHECK); did_rewrite = true; break; } } assert(did_rewrite, "must find Object::<init> to rewrite it"); } // rewrite methods, in two passes int len = _methods->length(); bool invokespecial_error = false; for (int i = len-1; i >= 0; i--) { Method* method = _methods->at(i); scan_method(method, false, &invokespecial_error); if (invokespecial_error) { // If you get an error here, there is no reversing bytecodes // This exception is stored for this class and no further attempt is // made at verifying or rewriting. THROW_MSG(vmSymbols::java_lang_InternalError(), "This classfile overflows invokespecial for interfaces " "and cannot be loaded"); return; } } // May have to fix invokedynamic bytecodes if invokestatic/InterfaceMethodref // entries had to be added. patch_invokedynamic_bytecodes(); // allocate constant pool cache, now that we've seen all the bytecodes make_constant_pool_cache(THREAD); // Restore bytecodes to their unrewritten state if there are exceptions // rewriting bytecodes or allocating the cpCache if (HAS_PENDING_EXCEPTION) { restore_bytecodes(); return; } // Relocate after everything, but still do this under the is_rewritten flag, // so methods with jsrs in custom class lists in aren't attempted to be // rewritten in the RO section of the shared archive. // Relocated bytecodes don't have to be restored, only the cp cache entries for (int i = len-1; i >= 0; i--) { methodHandle m(THREAD, _methods->at(i)); if (m->has_jsrs()) { m = rewrite_jsrs(m, THREAD); // Restore bytecodes to their unrewritten state if there are exceptions // relocating bytecodes. If some are relocated, that is ok because that // doesn't affect constant pool to cpCache rewriting. if (HAS_PENDING_EXCEPTION) { restore_bytecodes(); return; } // Method might have gotten rewritten. methods->at_put(i, m()); } } }