duke@435: /* never@2462: * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #include "precompiled.hpp" stefank@2314: #include "interpreter/bytecodes.hpp" stefank@2314: #include "interpreter/interpreter.hpp" stefank@2314: #include "interpreter/rewriter.hpp" stefank@2314: #include "memory/gcLocker.hpp" stefank@2314: #include "memory/oopFactory.hpp" stefank@2314: #include "memory/resourceArea.hpp" stefank@2314: #include "oops/generateOopMap.hpp" stefank@2314: #include "oops/objArrayOop.hpp" stefank@2314: #include "oops/oop.inline.hpp" stefank@2314: #include "prims/methodComparator.hpp" duke@435: jrose@1161: // Computes a CPC map (new_index -> original_index) for constant pool entries duke@435: // that are referred to by the interpreter at runtime via the constant pool cache. jrose@1161: // Also computes a CP map (original_index -> new_index). jrose@1161: // Marks entries in CP which require additional processing. jrose@1161: void Rewriter::compute_index_maps() { jrose@1161: const int length = _pool->length(); jrose@1161: init_cp_map(length); jrose@2015: jint tag_mask = 0; duke@435: for (int i = 0; i < length; i++) { jrose@1161: int tag = _pool->tag_at(i).value(); jrose@2015: tag_mask |= (1 << tag); jrose@1161: switch (tag) { jrose@1161: case JVM_CONSTANT_InterfaceMethodref: duke@435: case JVM_CONSTANT_Fieldref : // fall through duke@435: case JVM_CONSTANT_Methodref : // fall through jrose@1957: case JVM_CONSTANT_MethodHandle : // fall through jrose@1957: case JVM_CONSTANT_MethodType : // fall through jrose@2015: case JVM_CONSTANT_InvokeDynamic : // fall through jrose@1161: add_cp_cache_entry(i); jrose@1161: break; duke@435: } duke@435: } jrose@1161: jrose@1161: guarantee((int)_cp_cache_map.length()-1 <= (int)((u2)-1), jrose@1161: "all cp cache indexes fit in a u2"); jrose@2015: jrose@2015: _have_invoke_dynamic = ((tag_mask & (1 << JVM_CONSTANT_InvokeDynamic)) != 0); duke@435: } duke@435: coleenp@2945: // Unrewrite the bytecodes if an error occurs. coleenp@2945: void Rewriter::restore_bytecodes() { coleenp@2945: int len = _methods->length(); coleenp@2945: coleenp@2945: for (int i = len-1; i >= 0; i--) { coleenp@2945: methodOop method = (methodOop)_methods->obj_at(i); coleenp@2945: scan_method(method, true); coleenp@2945: } coleenp@2945: } duke@435: jrose@1161: // Creates a constant pool cache given a CPC map jrose@1161: void Rewriter::make_constant_pool_cache(TRAPS) { jrose@1161: const int length = _cp_cache_map.length(); jrose@1161: constantPoolCacheOop cache = ysr@2533: oopFactory::new_constantPoolCache(length, CHECK); ysr@2533: No_Safepoint_Verifier nsv; jrose@1161: cache->initialize(_cp_cache_map); jrose@2015: jrose@2353: // Don't bother with the next pass if there is no JVM_CONSTANT_InvokeDynamic. jrose@2015: if (_have_invoke_dynamic) { jrose@2015: for (int i = 0; i < length; i++) { jrose@2015: int pool_index = cp_cache_entry_pool_index(i); jrose@2015: if (pool_index >= 0 && jrose@2015: _pool->tag_at(pool_index).is_invoke_dynamic()) { jrose@2015: int bsm_index = _pool->invoke_dynamic_bootstrap_method_ref_index_at(pool_index); jrose@2742: assert(_pool->tag_at(bsm_index).is_method_handle(), "must be a MH constant"); jrose@2742: // There is a CP cache entry holding the BSM for these calls. jrose@2742: int bsm_cache_index = cp_entry_to_cp_cache(bsm_index); jrose@2742: cache->entry_at(i)->initialize_bootstrap_method_index_in_cache(bsm_cache_index); jrose@2015: } jrose@2015: } jrose@2015: } jrose@2015: jrose@1161: _pool->set_cache(cache); jrose@1161: cache->set_constant_pool(_pool()); duke@435: } duke@435: duke@435: duke@435: duke@435: // The new finalization semantics says that registration of duke@435: // finalizable objects must be performed on successful return from the duke@435: // Object. constructor. We could implement this trivially if duke@435: // were never rewritten but since JVMTI allows this to occur, a duke@435: // more complicated solution is required. A special return bytecode duke@435: // is used only by Object. to signal the finalization duke@435: // registration point. Additionally local 0 must be preserved so it's duke@435: // available to pass to the registration function. For simplicty we duke@435: // require that local 0 is never overwritten so it's available as an duke@435: // argument for registration. duke@435: duke@435: void Rewriter::rewrite_Object_init(methodHandle method, TRAPS) { duke@435: RawBytecodeStream bcs(method); duke@435: while (!bcs.is_last_bytecode()) { duke@435: Bytecodes::Code opcode = bcs.raw_next(); duke@435: switch (opcode) { duke@435: case Bytecodes::_return: *bcs.bcp() = Bytecodes::_return_register_finalizer; break; duke@435: duke@435: case Bytecodes::_istore: duke@435: case Bytecodes::_lstore: duke@435: case Bytecodes::_fstore: duke@435: case Bytecodes::_dstore: duke@435: case Bytecodes::_astore: duke@435: if (bcs.get_index() != 0) continue; duke@435: duke@435: // fall through duke@435: case Bytecodes::_istore_0: duke@435: case Bytecodes::_lstore_0: duke@435: case Bytecodes::_fstore_0: duke@435: case Bytecodes::_dstore_0: duke@435: case Bytecodes::_astore_0: duke@435: THROW_MSG(vmSymbols::java_lang_IncompatibleClassChangeError(), duke@435: "can't overwrite local 0 in Object."); duke@435: break; duke@435: } duke@435: } duke@435: } duke@435: duke@435: jrose@1161: // Rewrite a classfile-order CP index into a native-order CPC index. coleenp@2945: void Rewriter::rewrite_member_reference(address bcp, int offset, bool reverse) { jrose@1161: address p = bcp + offset; coleenp@2945: if (!reverse) { coleenp@2945: int cp_index = Bytes::get_Java_u2(p); coleenp@2945: int cache_index = cp_entry_to_cp_cache(cp_index); coleenp@2945: Bytes::put_native_u2(p, cache_index); coleenp@2945: } else { coleenp@2945: int cache_index = Bytes::get_native_u2(p); coleenp@2945: int pool_index = cp_cache_entry_pool_index(cache_index); coleenp@2945: Bytes::put_Java_u2(p, pool_index); coleenp@2945: } jrose@1161: } jrose@1161: jrose@1161: coleenp@2945: void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) { jrose@1161: address p = bcp + offset; coleenp@2945: assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode"); coleenp@2945: if (!reverse) { coleenp@2945: int cp_index = Bytes::get_Java_u2(p); coleenp@2945: int cpc = maybe_add_cp_cache_entry(cp_index); // add lazily coleenp@2945: int cpc2 = add_secondary_cp_cache_entry(cpc); jrose@1161: coleenp@2945: // Replace the trailing four bytes with a CPC index for the dynamic coleenp@2945: // call site. Unlike other CPC entries, there is one per bytecode, coleenp@2945: // not just one per distinct CP entry. In other words, the coleenp@2945: // CPC-to-CP relation is many-to-one for invokedynamic entries. coleenp@2945: // This means we must use a larger index size than u2 to address coleenp@2945: // all these entries. That is the main reason invokedynamic coleenp@2945: // must have a five-byte instruction format. (Of course, other JVM coleenp@2945: // implementations can use the bytes for other purposes.) coleenp@2945: Bytes::put_native_u4(p, constantPoolCacheOopDesc::encode_secondary_index(cpc2)); coleenp@2945: // Note: We use native_u4 format exclusively for 4-byte indexes. coleenp@2945: } else { coleenp@2945: int cache_index = constantPoolCacheOopDesc::decode_secondary_index( coleenp@2945: Bytes::get_native_u4(p)); coleenp@2945: int secondary_index = cp_cache_secondary_entry_main_index(cache_index); coleenp@2945: int pool_index = cp_cache_entry_pool_index(secondary_index); coleenp@2945: assert(_pool->tag_at(pool_index).is_invoke_dynamic(), "wrong index"); coleenp@2945: // zero out 4 bytes coleenp@2945: Bytes::put_Java_u4(p, 0); coleenp@2945: Bytes::put_Java_u2(p, pool_index); coleenp@2945: } jrose@1161: } jrose@1161: jrose@1161: jrose@1957: // Rewrite some ldc bytecodes to _fast_aldc coleenp@2945: void Rewriter::maybe_rewrite_ldc(address bcp, int offset, bool is_wide, coleenp@2945: bool reverse) { coleenp@2945: if (!reverse) { coleenp@2945: assert((*bcp) == (is_wide ? Bytecodes::_ldc_w : Bytecodes::_ldc), "not ldc bytecode"); coleenp@2945: address p = bcp + offset; coleenp@2945: int cp_index = is_wide ? Bytes::get_Java_u2(p) : (u1)(*p); coleenp@2945: constantTag tag = _pool->tag_at(cp_index).value(); coleenp@2945: if (tag.is_method_handle() || tag.is_method_type()) { coleenp@2945: int cache_index = cp_entry_to_cp_cache(cp_index); coleenp@2945: if (is_wide) { coleenp@2945: (*bcp) = Bytecodes::_fast_aldc_w; coleenp@2945: assert(cache_index == (u2)cache_index, "index overflow"); coleenp@2945: Bytes::put_native_u2(p, cache_index); coleenp@2945: } else { coleenp@2945: (*bcp) = Bytecodes::_fast_aldc; coleenp@2945: assert(cache_index == (u1)cache_index, "index overflow"); coleenp@2945: (*p) = (u1)cache_index; coleenp@2945: } coleenp@2945: } coleenp@2945: } else { coleenp@2945: Bytecodes::Code rewritten_bc = coleenp@2945: (is_wide ? Bytecodes::_fast_aldc_w : Bytecodes::_fast_aldc); coleenp@2945: if ((*bcp) == rewritten_bc) { coleenp@2945: address p = bcp + offset; coleenp@2945: int cache_index = is_wide ? Bytes::get_native_u2(p) : (u1)(*p); coleenp@2945: int pool_index = cp_cache_entry_pool_index(cache_index); coleenp@2945: if (is_wide) { coleenp@2945: (*bcp) = Bytecodes::_ldc_w; coleenp@2945: assert(pool_index == (u2)pool_index, "index overflow"); coleenp@2945: Bytes::put_Java_u2(p, pool_index); coleenp@2945: } else { coleenp@2945: (*bcp) = Bytecodes::_ldc; coleenp@2945: assert(pool_index == (u1)pool_index, "index overflow"); coleenp@2945: (*p) = (u1)pool_index; coleenp@2945: } jrose@1957: } jrose@1957: } jrose@1957: } jrose@1957: jrose@1957: duke@435: // Rewrites a method given the index_map information coleenp@2945: void Rewriter::scan_method(methodOop method, bool reverse) { duke@435: duke@435: int nof_jsrs = 0; duke@435: bool has_monitor_bytecodes = false; duke@435: duke@435: { duke@435: // We cannot tolerate a GC in this block, because we've duke@435: // cached the bytecodes in 'code_base'. If the methodOop duke@435: // moves, the bytecodes will also move. duke@435: No_Safepoint_Verifier nsv; duke@435: Bytecodes::Code c; duke@435: duke@435: // Bytecodes and their length duke@435: const address code_base = method->code_base(); duke@435: const int code_length = method->code_size(); duke@435: duke@435: int bc_length; duke@435: for (int bci = 0; bci < code_length; bci += bc_length) { duke@435: address bcp = code_base + bci; jrose@1161: int prefix_length = 0; duke@435: c = (Bytecodes::Code)(*bcp); duke@435: duke@435: // Since we have the code, see if we can get the length duke@435: // directly. Some more complicated bytecodes will report duke@435: // a length of zero, meaning we need to make another method duke@435: // call to calculate the length. duke@435: bc_length = Bytecodes::length_for(c); duke@435: if (bc_length == 0) { never@2462: bc_length = Bytecodes::length_at(method, bcp); duke@435: duke@435: // length_at will put us at the bytecode after the one modified duke@435: // by 'wide'. We don't currently examine any of the bytecodes duke@435: // modified by wide, but in case we do in the future... duke@435: if (c == Bytecodes::_wide) { jrose@1161: prefix_length = 1; duke@435: c = (Bytecodes::Code)bcp[1]; duke@435: } duke@435: } duke@435: duke@435: assert(bc_length != 0, "impossible bytecode length"); duke@435: duke@435: switch (c) { duke@435: case Bytecodes::_lookupswitch : { duke@435: #ifndef CC_INTERP never@2462: Bytecode_lookupswitch bc(method, bcp); jrose@1920: (*bcp) = ( never@2462: bc.number_of_pairs() < BinarySwitchThreshold duke@435: ? Bytecodes::_fast_linearswitch duke@435: : Bytecodes::_fast_binaryswitch duke@435: ); duke@435: #endif duke@435: break; duke@435: } coleenp@2945: case Bytecodes::_fast_linearswitch: coleenp@2945: case Bytecodes::_fast_binaryswitch: { coleenp@2945: #ifndef CC_INTERP coleenp@2945: (*bcp) = Bytecodes::_lookupswitch; coleenp@2945: #endif coleenp@2945: break; coleenp@2945: } duke@435: case Bytecodes::_getstatic : // fall through duke@435: case Bytecodes::_putstatic : // fall through duke@435: case Bytecodes::_getfield : // fall through duke@435: case Bytecodes::_putfield : // fall through duke@435: case Bytecodes::_invokevirtual : // fall through duke@435: case Bytecodes::_invokespecial : // fall through jrose@1161: case Bytecodes::_invokestatic : jrose@1161: case Bytecodes::_invokeinterface: coleenp@2945: rewrite_member_reference(bcp, prefix_length+1, reverse); duke@435: break; jrose@1161: case Bytecodes::_invokedynamic: coleenp@2945: rewrite_invokedynamic(bcp, prefix_length+1, reverse); jrose@1161: break; jrose@1957: case Bytecodes::_ldc: coleenp@2945: case Bytecodes::_fast_aldc: coleenp@2945: maybe_rewrite_ldc(bcp, prefix_length+1, false, reverse); jrose@1957: break; jrose@1957: case Bytecodes::_ldc_w: coleenp@2945: case Bytecodes::_fast_aldc_w: coleenp@2945: maybe_rewrite_ldc(bcp, prefix_length+1, true, reverse); jrose@1957: break; duke@435: case Bytecodes::_jsr : // fall through duke@435: case Bytecodes::_jsr_w : nof_jsrs++; break; duke@435: case Bytecodes::_monitorenter : // fall through duke@435: case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break; duke@435: } duke@435: } duke@435: } duke@435: duke@435: // Update access flags duke@435: if (has_monitor_bytecodes) { duke@435: method->set_has_monitor_bytecodes(); duke@435: } duke@435: duke@435: // The present of a jsr bytecode implies that the method might potentially duke@435: // have to be rewritten, so we run the oopMapGenerator on the method duke@435: if (nof_jsrs > 0) { duke@435: method->set_has_jsrs(); jrose@1161: // Second pass will revisit this method. coleenp@2945: assert(method->has_jsrs(), "didn't we just set this?"); jrose@1161: } jrose@1161: } duke@435: jrose@1161: // After constant pool is created, revisit methods containing jsrs. jrose@1161: methodHandle Rewriter::rewrite_jsrs(methodHandle method, TRAPS) { coleenp@2945: ResourceMark rm(THREAD); jrose@1161: ResolveOopMapConflicts romc(method); jrose@1161: methodHandle original_method = method; jrose@1161: method = romc.do_potential_rewrite(CHECK_(methodHandle())); jrose@1161: if (method() != original_method()) { jrose@1161: // Insert invalid bytecode into original methodOop and set jrose@1161: // interpreter entrypoint, so that a executing this method jrose@1161: // will manifest itself in an easy recognizable form. jrose@1161: address bcp = original_method->bcp_from(0); jrose@1161: *bcp = (u1)Bytecodes::_shouldnotreachhere; jrose@1161: int kind = Interpreter::method_kind(original_method); jrose@1161: original_method->set_interpreter_kind(kind); duke@435: } duke@435: jrose@1161: // Update monitor matching info. jrose@1161: if (romc.monitor_safe()) { jrose@1161: method->set_guaranteed_monitor_matching(); jrose@1161: } duke@435: duke@435: return method; duke@435: } duke@435: duke@435: void Rewriter::rewrite(instanceKlassHandle klass, TRAPS) { duke@435: ResourceMark rm(THREAD); twisti@1573: Rewriter rw(klass, klass->constants(), klass->methods(), CHECK); jrose@1161: // (That's all, folks.) jrose@1161: } jrose@1161: twisti@1573: twisti@1573: void Rewriter::rewrite(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS) { twisti@1573: ResourceMark rm(THREAD); twisti@1573: Rewriter rw(klass, cpool, methods, CHECK); twisti@1573: // (That's all, folks.) twisti@1573: } twisti@1573: twisti@1573: twisti@1573: Rewriter::Rewriter(instanceKlassHandle klass, constantPoolHandle cpool, objArrayHandle methods, TRAPS) jrose@1161: : _klass(klass), twisti@1573: _pool(cpool), twisti@1573: _methods(methods) jrose@1161: { jrose@1161: assert(_pool->cache() == NULL, "constant pool cache must not be set yet"); duke@435: duke@435: // determine index maps for methodOop rewriting jrose@1161: compute_index_maps(); duke@435: jrose@1161: if (RegisterFinalizersAtInit && _klass->name() == vmSymbols::java_lang_Object()) { jrose@1291: bool did_rewrite = false; jrose@1161: int i = _methods->length(); duke@435: while (i-- > 0) { jrose@1161: methodOop method = (methodOop)_methods->obj_at(i); duke@435: if (method->intrinsic_id() == vmIntrinsics::_Object_init) { duke@435: // rewrite the return bytecodes of Object. to register the duke@435: // object for finalization if needed. duke@435: methodHandle m(THREAD, method); duke@435: rewrite_Object_init(m, CHECK); jrose@1291: did_rewrite = true; duke@435: break; duke@435: } duke@435: } jrose@1291: assert(did_rewrite, "must find Object:: to rewrite it"); duke@435: } duke@435: jrose@1161: // rewrite methods, in two passes coleenp@2945: int len = _methods->length(); jrose@1161: coleenp@2945: for (int i = len-1; i >= 0; i--) { jrose@1161: methodOop method = (methodOop)_methods->obj_at(i); jrose@1161: scan_method(method); jrose@1161: } jrose@1161: jrose@1161: // allocate constant pool cache, now that we've seen all the bytecodes coleenp@2945: make_constant_pool_cache(THREAD); jrose@1161: coleenp@2945: // Restore bytecodes to their unrewritten state if there are exceptions coleenp@2945: // rewriting bytecodes or allocating the cpCache coleenp@2945: if (HAS_PENDING_EXCEPTION) { coleenp@2945: restore_bytecodes(); coleenp@2945: return; coleenp@2945: } coleenp@2945: } coleenp@2945: coleenp@2945: // Relocate jsr/rets in a method. This can't be done with the rewriter coleenp@2945: // stage because it can throw other exceptions, leaving the bytecodes coleenp@2945: // pointing at constant pool cache entries. coleenp@2945: // Link and check jvmti dependencies while we're iterating over the methods. coleenp@2945: // JSR292 code calls with a different set of methods, so two entry points. coleenp@2945: void Rewriter::relocate_and_link(instanceKlassHandle this_oop, TRAPS) { coleenp@2945: objArrayHandle methods(THREAD, this_oop->methods()); coleenp@2945: relocate_and_link(this_oop, methods, THREAD); coleenp@2945: } coleenp@2945: coleenp@2945: void Rewriter::relocate_and_link(instanceKlassHandle this_oop, coleenp@2945: objArrayHandle methods, TRAPS) { coleenp@2945: int len = methods->length(); coleenp@2945: for (int i = len-1; i >= 0; i--) { coleenp@2945: methodHandle m(THREAD, (methodOop)methods->obj_at(i)); jrose@1161: jrose@1161: if (m->has_jsrs()) { jrose@1161: m = rewrite_jsrs(m, CHECK); duke@435: // Method might have gotten rewritten. coleenp@2945: methods->obj_at_put(i, m()); duke@435: } jrose@1161: coleenp@2945: // Set up method entry points for compiler and interpreter . jrose@1161: m->link_method(m, CHECK); jrose@1929: coleenp@2945: // This is for JVMTI and unrelated to relocator but the last thing we do jrose@1929: #ifdef ASSERT jrose@1929: if (StressMethodComparator) { jrose@1929: static int nmc = 0; jrose@1929: for (int j = i; j >= 0 && j >= i-4; j--) { jrose@1929: if ((++nmc % 1000) == 0) tty->print_cr("Have run MethodComparator %d times...", nmc); coleenp@2945: bool z = MethodComparator::methods_EMCP(m(), coleenp@2945: (methodOop)methods->obj_at(j)); jrose@1929: if (j == i && !z) { jrose@1929: tty->print("MethodComparator FAIL: "); m->print(); m->print_codes(); jrose@1929: assert(z, "method must compare equal to itself"); jrose@1929: } jrose@1929: } jrose@1929: } jrose@1929: #endif //ASSERT duke@435: } duke@435: }