duke@435: /*
acorn@5848:  * Copyright (c) 2005, 2013, 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 "ci/ciArrayKlass.hpp"
stefank@2314: #include "ci/ciEnv.hpp"
stefank@2314: #include "ci/ciKlass.hpp"
stefank@2314: #include "ci/ciMethod.hpp"
stefank@2314: #include "code/dependencies.hpp"
stefank@2314: #include "compiler/compileLog.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
coleenp@4037: #include "runtime/handles.hpp"
stefank@2314: #include "runtime/handles.inline.hpp"
stefank@2314: #include "utilities/copy.hpp"
duke@435: 
duke@435: 
duke@435: #ifdef ASSERT
duke@435: static bool must_be_in_vm() {
duke@435:   Thread* thread = Thread::current();
duke@435:   if (thread->is_Java_thread())
duke@435:     return ((JavaThread*)thread)->thread_state() == _thread_in_vm;
duke@435:   else
duke@435:     return true;  //something like this: thread->is_VM_thread();
duke@435: }
duke@435: #endif //ASSERT
duke@435: 
duke@435: void Dependencies::initialize(ciEnv* env) {
duke@435:   Arena* arena = env->arena();
duke@435:   _oop_recorder = env->oop_recorder();
duke@435:   _log = env->log();
duke@435:   _dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0);
duke@435:   DEBUG_ONLY(_deps[end_marker] = NULL);
duke@435:   for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) {
coleenp@4037:     _deps[i] = new(arena) GrowableArray<ciBaseObject*>(arena, 10, 0, 0);
duke@435:   }
duke@435:   _content_bytes = NULL;
duke@435:   _size_in_bytes = (size_t)-1;
duke@435: 
duke@435:   assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity");
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_evol_method(ciMethod* m) {
duke@435:   assert_common_1(evol_method, m);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_leaf_type(ciKlass* ctxk) {
duke@435:   if (ctxk->is_array_klass()) {
duke@435:     // As a special case, support this assertion on an array type,
duke@435:     // which reduces to an assertion on its element type.
duke@435:     // Note that this cannot be done with assertions that
duke@435:     // relate to concreteness or abstractness.
duke@435:     ciType* elemt = ctxk->as_array_klass()->base_element_type();
duke@435:     if (!elemt->is_instance_klass())  return;   // Ex:  int[][]
duke@435:     ctxk = elemt->as_instance_klass();
duke@435:     //if (ctxk->is_final())  return;            // Ex:  String[][]
duke@435:   }
duke@435:   check_ctxk(ctxk);
duke@435:   assert_common_1(leaf_type, ctxk);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck) {
duke@435:   check_ctxk_abstract(ctxk);
duke@435:   assert_common_2(abstract_with_unique_concrete_subtype, ctxk, conck);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_abstract_with_no_concrete_subtype(ciKlass* ctxk) {
duke@435:   check_ctxk_abstract(ctxk);
duke@435:   assert_common_1(abstract_with_no_concrete_subtype, ctxk);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_concrete_with_no_concrete_subtype(ciKlass* ctxk) {
duke@435:   check_ctxk_concrete(ctxk);
duke@435:   assert_common_1(concrete_with_no_concrete_subtype, ctxk);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm) {
duke@435:   check_ctxk(ctxk);
duke@435:   assert_common_2(unique_concrete_method, ctxk, uniqm);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2) {
duke@435:   check_ctxk(ctxk);
duke@435:   assert_common_3(abstract_with_exclusive_concrete_subtypes_2, ctxk, k1, k2);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2) {
duke@435:   check_ctxk(ctxk);
duke@435:   assert_common_3(exclusive_concrete_methods_2, ctxk, m1, m2);
duke@435: }
duke@435: 
duke@435: void Dependencies::assert_has_no_finalizable_subclasses(ciKlass* ctxk) {
duke@435:   check_ctxk(ctxk);
duke@435:   assert_common_1(no_finalizable_subclasses, ctxk);
duke@435: }
duke@435: 
twisti@3094: void Dependencies::assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle) {
twisti@3094:   check_ctxk(call_site->klass());
twisti@3094:   assert_common_2(call_site_target_value, call_site, method_handle);
twisti@3050: }
twisti@3050: 
duke@435: // Helper function.  If we are adding a new dep. under ctxk2,
duke@435: // try to find an old dep. under a broader* ctxk1.  If there is
duke@435: //
coleenp@4037: bool Dependencies::maybe_merge_ctxk(GrowableArray<ciBaseObject*>* deps,
duke@435:                                     int ctxk_i, ciKlass* ctxk2) {
coleenp@4037:   ciKlass* ctxk1 = deps->at(ctxk_i)->as_metadata()->as_klass();
duke@435:   if (ctxk2->is_subtype_of(ctxk1)) {
duke@435:     return true;  // success, and no need to change
duke@435:   } else if (ctxk1->is_subtype_of(ctxk2)) {
duke@435:     // new context class fully subsumes previous one
duke@435:     deps->at_put(ctxk_i, ctxk2);
duke@435:     return true;
duke@435:   } else {
duke@435:     return false;
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: void Dependencies::assert_common_1(DepType dept, ciBaseObject* x) {
duke@435:   assert(dep_args(dept) == 1, "sanity");
duke@435:   log_dependency(dept, x);
coleenp@4037:   GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435: 
duke@435:   // see if the same (or a similar) dep is already recorded
duke@435:   if (note_dep_seen(dept, x)) {
duke@435:     assert(deps->find(x) >= 0, "sanity");
duke@435:   } else {
duke@435:     deps->append(x);
duke@435:   }
duke@435: }
duke@435: 
twisti@3094: void Dependencies::assert_common_2(DepType dept,
coleenp@4037:                                    ciBaseObject* x0, ciBaseObject* x1) {
duke@435:   assert(dep_args(dept) == 2, "sanity");
twisti@3094:   log_dependency(dept, x0, x1);
coleenp@4037:   GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435: 
duke@435:   // see if the same (or a similar) dep is already recorded
twisti@3094:   bool has_ctxk = has_explicit_context_arg(dept);
twisti@3094:   if (has_ctxk) {
twisti@3094:     assert(dep_context_arg(dept) == 0, "sanity");
twisti@3094:     if (note_dep_seen(dept, x1)) {
twisti@3094:       // look in this bucket for redundant assertions
twisti@3094:       const int stride = 2;
twisti@3094:       for (int i = deps->length(); (i -= stride) >= 0; ) {
coleenp@4037:         ciBaseObject* y1 = deps->at(i+1);
twisti@3094:         if (x1 == y1) {  // same subject; check the context
coleenp@4037:           if (maybe_merge_ctxk(deps, i+0, x0->as_metadata()->as_klass())) {
twisti@3094:             return;
twisti@3094:           }
twisti@3094:         }
twisti@3094:       }
twisti@3094:     }
twisti@3094:   } else {
twisti@3094:     assert(dep_implicit_context_arg(dept) == 0, "sanity");
twisti@3094:     if (note_dep_seen(dept, x0) && note_dep_seen(dept, x1)) {
twisti@3094:       // look in this bucket for redundant assertions
twisti@3094:       const int stride = 2;
twisti@3094:       for (int i = deps->length(); (i -= stride) >= 0; ) {
coleenp@4037:         ciBaseObject* y0 = deps->at(i+0);
coleenp@4037:         ciBaseObject* y1 = deps->at(i+1);
twisti@3094:         if (x0 == y0 && x1 == y1) {
duke@435:           return;
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // append the assertion in the correct bucket:
twisti@3094:   deps->append(x0);
twisti@3094:   deps->append(x1);
duke@435: }
duke@435: 
twisti@3094: void Dependencies::assert_common_3(DepType dept,
coleenp@4037:                                    ciKlass* ctxk, ciBaseObject* x, ciBaseObject* x2) {
duke@435:   assert(dep_context_arg(dept) == 0, "sanity");
duke@435:   assert(dep_args(dept) == 3, "sanity");
duke@435:   log_dependency(dept, ctxk, x, x2);
coleenp@4037:   GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435: 
duke@435:   // try to normalize an unordered pair:
duke@435:   bool swap = false;
duke@435:   switch (dept) {
duke@435:   case abstract_with_exclusive_concrete_subtypes_2:
coleenp@4037:     swap = (x->ident() > x2->ident() && x->as_metadata()->as_klass() != ctxk);
duke@435:     break;
duke@435:   case exclusive_concrete_methods_2:
coleenp@4037:     swap = (x->ident() > x2->ident() && x->as_metadata()->as_method()->holder() != ctxk);
duke@435:     break;
duke@435:   }
coleenp@4037:   if (swap) { ciBaseObject* t = x; x = x2; x2 = t; }
duke@435: 
duke@435:   // see if the same (or a similar) dep is already recorded
duke@435:   if (note_dep_seen(dept, x) && note_dep_seen(dept, x2)) {
duke@435:     // look in this bucket for redundant assertions
duke@435:     const int stride = 3;
duke@435:     for (int i = deps->length(); (i -= stride) >= 0; ) {
coleenp@4037:       ciBaseObject* y  = deps->at(i+1);
coleenp@4037:       ciBaseObject* y2 = deps->at(i+2);
duke@435:       if (x == y && x2 == y2) {  // same subjects; check the context
duke@435:         if (maybe_merge_ctxk(deps, i+0, ctxk)) {
duke@435:           return;
duke@435:         }
duke@435:       }
duke@435:     }
duke@435:   }
duke@435:   // append the assertion in the correct bucket:
duke@435:   deps->append(ctxk);
duke@435:   deps->append(x);
duke@435:   deps->append(x2);
duke@435: }
duke@435: 
duke@435: /// Support for encoding dependencies into an nmethod:
duke@435: 
duke@435: void Dependencies::copy_to(nmethod* nm) {
duke@435:   address beg = nm->dependencies_begin();
duke@435:   address end = nm->dependencies_end();
duke@435:   guarantee(end - beg >= (ptrdiff_t) size_in_bytes(), "bad sizing");
duke@435:   Copy::disjoint_words((HeapWord*) content_bytes(),
duke@435:                        (HeapWord*) beg,
duke@435:                        size_in_bytes() / sizeof(HeapWord));
duke@435:   assert(size_in_bytes() % sizeof(HeapWord) == 0, "copy by words");
duke@435: }
duke@435: 
coleenp@4037: static int sort_dep(ciBaseObject** p1, ciBaseObject** p2, int narg) {
duke@435:   for (int i = 0; i < narg; i++) {
duke@435:     int diff = p1[i]->ident() - p2[i]->ident();
duke@435:     if (diff != 0)  return diff;
duke@435:   }
duke@435:   return 0;
duke@435: }
coleenp@4037: static int sort_dep_arg_1(ciBaseObject** p1, ciBaseObject** p2)
duke@435: { return sort_dep(p1, p2, 1); }
coleenp@4037: static int sort_dep_arg_2(ciBaseObject** p1, ciBaseObject** p2)
duke@435: { return sort_dep(p1, p2, 2); }
coleenp@4037: static int sort_dep_arg_3(ciBaseObject** p1, ciBaseObject** p2)
duke@435: { return sort_dep(p1, p2, 3); }
duke@435: 
duke@435: void Dependencies::sort_all_deps() {
duke@435:   for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
duke@435:     DepType dept = (DepType)deptv;
coleenp@4037:     GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435:     if (deps->length() <= 1)  continue;
duke@435:     switch (dep_args(dept)) {
duke@435:     case 1: deps->sort(sort_dep_arg_1, 1); break;
duke@435:     case 2: deps->sort(sort_dep_arg_2, 2); break;
duke@435:     case 3: deps->sort(sort_dep_arg_3, 3); break;
duke@435:     default: ShouldNotReachHere();
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: size_t Dependencies::estimate_size_in_bytes() {
duke@435:   size_t est_size = 100;
duke@435:   for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
duke@435:     DepType dept = (DepType)deptv;
coleenp@4037:     GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435:     est_size += deps->length()*2;  // tags and argument(s)
duke@435:   }
duke@435:   return est_size;
duke@435: }
duke@435: 
coleenp@4037: ciKlass* Dependencies::ctxk_encoded_as_null(DepType dept, ciBaseObject* x) {
duke@435:   switch (dept) {
duke@435:   case abstract_with_exclusive_concrete_subtypes_2:
coleenp@4037:     return x->as_metadata()->as_klass();
duke@435:   case unique_concrete_method:
duke@435:   case exclusive_concrete_methods_2:
coleenp@4037:     return x->as_metadata()->as_method()->holder();
duke@435:   }
duke@435:   return NULL;  // let NULL be NULL
duke@435: }
duke@435: 
coleenp@4037: Klass* Dependencies::ctxk_encoded_as_null(DepType dept, Metadata* x) {
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   switch (dept) {
duke@435:   case abstract_with_exclusive_concrete_subtypes_2:
duke@435:     assert(x->is_klass(), "sanity");
coleenp@4037:     return (Klass*) x;
duke@435:   case unique_concrete_method:
duke@435:   case exclusive_concrete_methods_2:
duke@435:     assert(x->is_method(), "sanity");
coleenp@4037:     return ((Method*)x)->method_holder();
duke@435:   }
duke@435:   return NULL;  // let NULL be NULL
duke@435: }
duke@435: 
duke@435: void Dependencies::encode_content_bytes() {
duke@435:   sort_all_deps();
duke@435: 
duke@435:   // cast is safe, no deps can overflow INT_MAX
duke@435:   CompressedWriteStream bytes((int)estimate_size_in_bytes());
duke@435: 
duke@435:   for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
duke@435:     DepType dept = (DepType)deptv;
coleenp@4037:     GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435:     if (deps->length() == 0)  continue;
duke@435:     int stride = dep_args(dept);
duke@435:     int ctxkj  = dep_context_arg(dept);  // -1 if no context arg
duke@435:     assert(stride > 0, "sanity");
duke@435:     for (int i = 0; i < deps->length(); i += stride) {
duke@435:       jbyte code_byte = (jbyte)dept;
duke@435:       int skipj = -1;
duke@435:       if (ctxkj >= 0 && ctxkj+1 < stride) {
coleenp@4037:         ciKlass*  ctxk = deps->at(i+ctxkj+0)->as_metadata()->as_klass();
coleenp@4037:         ciBaseObject* x     = deps->at(i+ctxkj+1);  // following argument
duke@435:         if (ctxk == ctxk_encoded_as_null(dept, x)) {
duke@435:           skipj = ctxkj;  // we win:  maybe one less oop to keep track of
duke@435:           code_byte |= default_context_type_bit;
duke@435:         }
duke@435:       }
duke@435:       bytes.write_byte(code_byte);
duke@435:       for (int j = 0; j < stride; j++) {
duke@435:         if (j == skipj)  continue;
coleenp@4037:         ciBaseObject* v = deps->at(i+j);
vlivanov@4155:         int idx;
coleenp@4037:         if (v->is_object()) {
vlivanov@4155:           idx = _oop_recorder->find_index(v->as_object()->constant_encoding());
coleenp@4037:         } else {
coleenp@4037:           ciMetadata* meta = v->as_metadata();
vlivanov@4155:           idx = _oop_recorder->find_index(meta->constant_encoding());
coleenp@4037:         }
vlivanov@4155:         bytes.write_int(idx);
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // write a sentinel byte to mark the end
duke@435:   bytes.write_byte(end_marker);
duke@435: 
duke@435:   // round it out to a word boundary
duke@435:   while (bytes.position() % sizeof(HeapWord) != 0) {
duke@435:     bytes.write_byte(end_marker);
duke@435:   }
duke@435: 
duke@435:   // check whether the dept byte encoding really works
duke@435:   assert((jbyte)default_context_type_bit != 0, "byte overflow");
duke@435: 
duke@435:   _content_bytes = bytes.buffer();
duke@435:   _size_in_bytes = bytes.position();
duke@435: }
duke@435: 
duke@435: 
duke@435: const char* Dependencies::_dep_name[TYPE_LIMIT] = {
duke@435:   "end_marker",
duke@435:   "evol_method",
duke@435:   "leaf_type",
duke@435:   "abstract_with_unique_concrete_subtype",
duke@435:   "abstract_with_no_concrete_subtype",
duke@435:   "concrete_with_no_concrete_subtype",
duke@435:   "unique_concrete_method",
duke@435:   "abstract_with_exclusive_concrete_subtypes_2",
duke@435:   "exclusive_concrete_methods_2",
twisti@3050:   "no_finalizable_subclasses",
twisti@3050:   "call_site_target_value"
duke@435: };
duke@435: 
duke@435: int Dependencies::_dep_args[TYPE_LIMIT] = {
duke@435:   -1,// end_marker
duke@435:   1, // evol_method m
duke@435:   1, // leaf_type ctxk
duke@435:   2, // abstract_with_unique_concrete_subtype ctxk, k
duke@435:   1, // abstract_with_no_concrete_subtype ctxk
duke@435:   1, // concrete_with_no_concrete_subtype ctxk
duke@435:   2, // unique_concrete_method ctxk, m
duke@435:   3, // unique_concrete_subtypes_2 ctxk, k1, k2
duke@435:   3, // unique_concrete_methods_2 ctxk, m1, m2
twisti@3050:   1, // no_finalizable_subclasses ctxk
twisti@3094:   2  // call_site_target_value call_site, method_handle
duke@435: };
duke@435: 
duke@435: const char* Dependencies::dep_name(Dependencies::DepType dept) {
duke@435:   if (!dept_in_mask(dept, all_types))  return "?bad-dep?";
duke@435:   return _dep_name[dept];
duke@435: }
duke@435: 
duke@435: int Dependencies::dep_args(Dependencies::DepType dept) {
duke@435:   if (!dept_in_mask(dept, all_types))  return -1;
duke@435:   return _dep_args[dept];
duke@435: }
duke@435: 
twisti@3050: void Dependencies::check_valid_dependency_type(DepType dept) {
twisti@3094:   guarantee(FIRST_TYPE <= dept && dept < TYPE_LIMIT, err_msg("invalid dependency type: %d", (int) dept));
twisti@3050: }
twisti@3050: 
duke@435: // for the sake of the compiler log, print out current dependencies:
duke@435: void Dependencies::log_all_dependencies() {
duke@435:   if (log() == NULL)  return;
coleenp@4037:   ciBaseObject* args[max_arg_count];
duke@435:   for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
duke@435:     DepType dept = (DepType)deptv;
coleenp@4037:     GrowableArray<ciBaseObject*>* deps = _deps[dept];
duke@435:     if (deps->length() == 0)  continue;
duke@435:     int stride = dep_args(dept);
duke@435:     for (int i = 0; i < deps->length(); i += stride) {
duke@435:       for (int j = 0; j < stride; j++) {
duke@435:         // flush out the identities before printing
duke@435:         args[j] = deps->at(i+j);
duke@435:       }
duke@435:       write_dependency_to(log(), dept, stride, args);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: void Dependencies::write_dependency_to(CompileLog* log,
duke@435:                                        DepType dept,
coleenp@4037:                                        int nargs, DepArgument args[],
coleenp@4037:                                        Klass* witness) {
duke@435:   if (log == NULL) {
duke@435:     return;
duke@435:   }
duke@435:   ciEnv* env = ciEnv::current();
coleenp@4037:   ciBaseObject* ciargs[max_arg_count];
duke@435:   assert(nargs <= max_arg_count, "oob");
duke@435:   for (int j = 0; j < nargs; j++) {
coleenp@4037:     if (args[j].is_oop()) {
coleenp@4037:       ciargs[j] = env->get_object(args[j].oop_value());
coleenp@4037:     } else {
coleenp@4037:       ciargs[j] = env->get_metadata(args[j].metadata_value());
coleenp@4037:     }
duke@435:   }
duke@435:   Dependencies::write_dependency_to(log, dept, nargs, ciargs, witness);
duke@435: }
duke@435: 
duke@435: void Dependencies::write_dependency_to(CompileLog* log,
duke@435:                                        DepType dept,
coleenp@4037:                                        int nargs, ciBaseObject* args[],
coleenp@4037:                                        Klass* witness) {
duke@435:   if (log == NULL)  return;
duke@435:   assert(nargs <= max_arg_count, "oob");
duke@435:   int argids[max_arg_count];
duke@435:   int ctxkj = dep_context_arg(dept);  // -1 if no context arg
duke@435:   int j;
duke@435:   for (j = 0; j < nargs; j++) {
coleenp@4037:     if (args[j]->is_object()) {
coleenp@4037:       argids[j] = log->identify(args[j]->as_object());
coleenp@4037:     } else {
coleenp@4037:       argids[j] = log->identify(args[j]->as_metadata());
coleenp@4037:     }
duke@435:   }
duke@435:   if (witness != NULL) {
duke@435:     log->begin_elem("dependency_failed");
duke@435:   } else {
duke@435:     log->begin_elem("dependency");
duke@435:   }
duke@435:   log->print(" type='%s'", dep_name(dept));
duke@435:   if (ctxkj >= 0) {
duke@435:     log->print(" ctxk='%d'", argids[ctxkj]);
duke@435:   }
duke@435:   // write remaining arguments, if any.
duke@435:   for (j = 0; j < nargs; j++) {
duke@435:     if (j == ctxkj)  continue;  // already logged
duke@435:     if (j == 1) {
duke@435:       log->print(  " x='%d'",    argids[j]);
duke@435:     } else {
duke@435:       log->print(" x%d='%d'", j, argids[j]);
duke@435:     }
duke@435:   }
duke@435:   if (witness != NULL) {
duke@435:     log->object("witness", witness);
duke@435:     log->stamp();
duke@435:   }
duke@435:   log->end_elem();
duke@435: }
duke@435: 
duke@435: void Dependencies::write_dependency_to(xmlStream* xtty,
duke@435:                                        DepType dept,
coleenp@4037:                                        int nargs, DepArgument args[],
coleenp@4037:                                        Klass* witness) {
duke@435:   if (xtty == NULL)  return;
duke@435:   ttyLocker ttyl;
duke@435:   int ctxkj = dep_context_arg(dept);  // -1 if no context arg
duke@435:   if (witness != NULL) {
duke@435:     xtty->begin_elem("dependency_failed");
duke@435:   } else {
duke@435:     xtty->begin_elem("dependency");
duke@435:   }
duke@435:   xtty->print(" type='%s'", dep_name(dept));
duke@435:   if (ctxkj >= 0) {
coleenp@4037:     xtty->object("ctxk", args[ctxkj].metadata_value());
duke@435:   }
duke@435:   // write remaining arguments, if any.
duke@435:   for (int j = 0; j < nargs; j++) {
duke@435:     if (j == ctxkj)  continue;  // already logged
duke@435:     if (j == 1) {
coleenp@4037:       if (args[j].is_oop()) {
coleenp@4037:         xtty->object("x", args[j].oop_value());
coleenp@4037:       } else {
coleenp@4037:         xtty->object("x", args[j].metadata_value());
coleenp@4037:       }
duke@435:     } else {
duke@435:       char xn[10]; sprintf(xn, "x%d", j);
coleenp@4037:       if (args[j].is_oop()) {
coleenp@4037:         xtty->object(xn, args[j].oop_value());
coleenp@4037:       } else {
coleenp@4037:         xtty->object(xn, args[j].metadata_value());
coleenp@4037:       }
duke@435:     }
duke@435:   }
duke@435:   if (witness != NULL) {
duke@435:     xtty->object("witness", witness);
duke@435:     xtty->stamp();
duke@435:   }
duke@435:   xtty->end_elem();
duke@435: }
duke@435: 
coleenp@4037: void Dependencies::print_dependency(DepType dept, int nargs, DepArgument args[],
coleenp@4037:                                     Klass* witness) {
duke@435:   ResourceMark rm;
duke@435:   ttyLocker ttyl;   // keep the following output all in one block
duke@435:   tty->print_cr("%s of type %s",
duke@435:                 (witness == NULL)? "Dependency": "Failed dependency",
duke@435:                 dep_name(dept));
duke@435:   // print arguments
duke@435:   int ctxkj = dep_context_arg(dept);  // -1 if no context arg
duke@435:   for (int j = 0; j < nargs; j++) {
coleenp@4037:     DepArgument arg = args[j];
duke@435:     bool put_star = false;
coleenp@4037:     if (arg.is_null())  continue;
duke@435:     const char* what;
duke@435:     if (j == ctxkj) {
coleenp@4037:       assert(arg.is_metadata(), "must be");
duke@435:       what = "context";
coleenp@4037:       put_star = !Dependencies::is_concrete_klass((Klass*)arg.metadata_value());
coleenp@4037:     } else if (arg.is_method()) {
duke@435:       what = "method ";
coleenp@4037:       put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value());
coleenp@4037:     } else if (arg.is_klass()) {
duke@435:       what = "class  ";
duke@435:     } else {
duke@435:       what = "object ";
duke@435:     }
duke@435:     tty->print("  %s = %s", what, (put_star? "*": ""));
coleenp@4037:     if (arg.is_klass())
hseigel@4278:       tty->print("%s", ((Klass*)arg.metadata_value())->external_name());
coleenp@4037:     else if (arg.is_method())
coleenp@4037:       ((Method*)arg.metadata_value())->print_value();
duke@435:     else
coleenp@4037:       ShouldNotReachHere(); // Provide impl for this type.
duke@435:     tty->cr();
duke@435:   }
duke@435:   if (witness != NULL) {
duke@435:     bool put_star = !Dependencies::is_concrete_klass(witness);
duke@435:     tty->print_cr("  witness = %s%s",
duke@435:                   (put_star? "*": ""),
hseigel@4278:                   witness->external_name());
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: void Dependencies::DepStream::log_dependency(Klass* witness) {
duke@435:   if (_deps == NULL && xtty == NULL)  return;  // fast cutout for runtime
minqi@4267:   ResourceMark rm;
duke@435:   int nargs = argument_count();
coleenp@4037:   DepArgument args[max_arg_count];
duke@435:   for (int j = 0; j < nargs; j++) {
coleenp@4037:     if (type() == call_site_target_value) {
coleenp@4037:       args[j] = argument_oop(j);
coleenp@4037:     } else {
vlivanov@4155:       args[j] = argument(j);
vlivanov@4155:     }
coleenp@4037:   }
duke@435:   if (_deps != NULL && _deps->log() != NULL) {
duke@435:     Dependencies::write_dependency_to(_deps->log(),
duke@435:                                       type(), nargs, args, witness);
duke@435:   } else {
duke@435:     Dependencies::write_dependency_to(xtty,
duke@435:                                       type(), nargs, args, witness);
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: void Dependencies::DepStream::print_dependency(Klass* witness, bool verbose) {
duke@435:   int nargs = argument_count();
coleenp@4037:   DepArgument args[max_arg_count];
duke@435:   for (int j = 0; j < nargs; j++) {
duke@435:     args[j] = argument(j);
duke@435:   }
duke@435:   Dependencies::print_dependency(type(), nargs, args, witness);
duke@435:   if (verbose) {
duke@435:     if (_code != NULL) {
duke@435:       tty->print("  code: ");
duke@435:       _code->print_value_on(tty);
duke@435:       tty->cr();
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: /// Dependency stream support (decodes dependencies from an nmethod):
duke@435: 
duke@435: #ifdef ASSERT
duke@435: void Dependencies::DepStream::initial_asserts(size_t byte_limit) {
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   _byte_limit = byte_limit;
duke@435:   _type       = (DepType)(end_marker-1);  // defeat "already at end" assert
duke@435:   assert((_code!=NULL) + (_deps!=NULL) == 1, "one or t'other");
duke@435: }
duke@435: #endif //ASSERT
duke@435: 
duke@435: bool Dependencies::DepStream::next() {
duke@435:   assert(_type != end_marker, "already at end");
duke@435:   if (_bytes.position() == 0 && _code != NULL
duke@435:       && _code->dependencies_size() == 0) {
duke@435:     // Method has no dependencies at all.
duke@435:     return false;
duke@435:   }
duke@435:   int code_byte = (_bytes.read_byte() & 0xFF);
duke@435:   if (code_byte == end_marker) {
duke@435:     DEBUG_ONLY(_type = end_marker);
duke@435:     return false;
duke@435:   } else {
duke@435:     int ctxk_bit = (code_byte & Dependencies::default_context_type_bit);
duke@435:     code_byte -= ctxk_bit;
duke@435:     DepType dept = (DepType)code_byte;
duke@435:     _type = dept;
twisti@3094:     Dependencies::check_valid_dependency_type(dept);
duke@435:     int stride = _dep_args[dept];
duke@435:     assert(stride == dep_args(dept), "sanity");
duke@435:     int skipj = -1;
duke@435:     if (ctxk_bit != 0) {
duke@435:       skipj = 0;  // currently the only context argument is at zero
duke@435:       assert(skipj == dep_context_arg(dept), "zero arg always ctxk");
duke@435:     }
duke@435:     for (int j = 0; j < stride; j++) {
duke@435:       _xi[j] = (j == skipj)? 0: _bytes.read_int();
duke@435:     }
duke@435:     DEBUG_ONLY(_xi[stride] = -1);   // help detect overruns
duke@435:     return true;
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: inline Metadata* Dependencies::DepStream::recorded_metadata_at(int i) {
coleenp@4037:   Metadata* o = NULL;
coleenp@4037:   if (_code != NULL) {
coleenp@4037:     o = _code->metadata_at(i);
coleenp@4037:   } else {
coleenp@4037:     o = _deps->oop_recorder()->metadata_at(i);
coleenp@4037:   }
coleenp@5307:   assert(o == NULL || o->is_metaspace_object(),
coleenp@5307:          err_msg("Should be metadata " PTR_FORMAT, o));
coleenp@4037:   return o;
coleenp@4037: }
coleenp@4037: 
duke@435: inline oop Dependencies::DepStream::recorded_oop_at(int i) {
duke@435:   return (_code != NULL)
duke@435:          ? _code->oop_at(i)
coleenp@4037:     : JNIHandles::resolve(_deps->oop_recorder()->oop_at(i));
duke@435: }
duke@435: 
coleenp@4037: Metadata* Dependencies::DepStream::argument(int i) {
coleenp@4037:   Metadata* result = recorded_metadata_at(argument_index(i));
vlivanov@4155: 
vlivanov@4155:   if (result == NULL) { // Explicit context argument can be compressed
vlivanov@4155:     int ctxkj = dep_context_arg(type());  // -1 if no explicit context arg
vlivanov@4155:     if (ctxkj >= 0 && i == ctxkj && ctxkj+1 < argument_count()) {
vlivanov@4155:       result = ctxk_encoded_as_null(type(), argument(ctxkj+1));
vlivanov@4155:     }
vlivanov@4155:   }
vlivanov@4155: 
coleenp@4037:   assert(result == NULL || result->is_klass() || result->is_method(), "must be");
coleenp@4037:   return result;
duke@435: }
duke@435: 
coleenp@4037: oop Dependencies::DepStream::argument_oop(int i) {
coleenp@4037:   oop result = recorded_oop_at(argument_index(i));
coleenp@4037:   assert(result == NULL || result->is_oop(), "must be");
coleenp@4037:   return result;
coleenp@4037: }
coleenp@4037: 
coleenp@4037: Klass* Dependencies::DepStream::context_type() {
duke@435:   assert(must_be_in_vm(), "raw oops here");
twisti@3094: 
twisti@3094:   // Most dependencies have an explicit context type argument.
twisti@3094:   {
vlivanov@4155:     int ctxkj = dep_context_arg(type());  // -1 if no explicit context arg
twisti@3094:     if (ctxkj >= 0) {
coleenp@4037:       Metadata* k = argument(ctxkj);
vlivanov@4155:       assert(k != NULL && k->is_klass(), "type check");
vlivanov@4155:       return (Klass*)k;
twisti@3094:     }
twisti@3094:   }
twisti@3094: 
twisti@3094:   // Some dependencies are using the klass of the first object
twisti@3094:   // argument as implicit context type (e.g. call_site_target_value).
twisti@3094:   {
vlivanov@4155:     int ctxkj = dep_implicit_context_arg(type());
twisti@3094:     if (ctxkj >= 0) {
coleenp@4037:       Klass* k = argument_oop(ctxkj)->klass();
vlivanov@4155:       assert(k != NULL && k->is_klass(), "type check");
coleenp@4037:       return (Klass*) k;
duke@435:     }
duke@435:   }
twisti@3094: 
twisti@3094:   // And some dependencies don't have a context type at all,
twisti@3094:   // e.g. evol_method.
twisti@3094:   return NULL;
duke@435: }
duke@435: 
duke@435: /// Checking dependencies:
duke@435: 
duke@435: // This hierarchy walker inspects subtypes of a given type,
duke@435: // trying to find a "bad" class which breaks a dependency.
duke@435: // Such a class is called a "witness" to the broken dependency.
duke@435: // While searching around, we ignore "participants", which
duke@435: // are already known to the dependency.
duke@435: class ClassHierarchyWalker {
duke@435:  public:
duke@435:   enum { PARTICIPANT_LIMIT = 3 };
duke@435: 
duke@435:  private:
duke@435:   // optional method descriptor to check for:
coleenp@2497:   Symbol* _name;
coleenp@2497:   Symbol* _signature;
duke@435: 
duke@435:   // special classes which are not allowed to be witnesses:
coleenp@4037:   Klass*    _participants[PARTICIPANT_LIMIT+1];
duke@435:   int       _num_participants;
duke@435: 
duke@435:   // cache of method lookups
coleenp@4037:   Method* _found_methods[PARTICIPANT_LIMIT+1];
duke@435: 
duke@435:   // if non-zero, tells how many witnesses to convert to participants
duke@435:   int       _record_witnesses;
duke@435: 
coleenp@4037:   void initialize(Klass* participant) {
duke@435:     _record_witnesses = 0;
duke@435:     _participants[0]  = participant;
duke@435:     _found_methods[0] = NULL;
duke@435:     _num_participants = 0;
duke@435:     if (participant != NULL) {
duke@435:       // Terminating NULL.
duke@435:       _participants[1] = NULL;
duke@435:       _found_methods[1] = NULL;
duke@435:       _num_participants = 1;
duke@435:     }
duke@435:   }
duke@435: 
coleenp@4037:   void initialize_from_method(Method* m) {
duke@435:     assert(m != NULL && m->is_method(), "sanity");
duke@435:     _name      = m->name();
duke@435:     _signature = m->signature();
duke@435:   }
duke@435: 
duke@435:  public:
duke@435:   // The walker is initialized to recognize certain methods and/or types
duke@435:   // as friendly participants.
coleenp@4037:   ClassHierarchyWalker(Klass* participant, Method* m) {
duke@435:     initialize_from_method(m);
duke@435:     initialize(participant);
duke@435:   }
coleenp@4037:   ClassHierarchyWalker(Method* m) {
duke@435:     initialize_from_method(m);
duke@435:     initialize(NULL);
duke@435:   }
coleenp@4037:   ClassHierarchyWalker(Klass* participant = NULL) {
duke@435:     _name      = NULL;
duke@435:     _signature = NULL;
duke@435:     initialize(participant);
duke@435:   }
duke@435: 
duke@435:   // This is common code for two searches:  One for concrete subtypes,
duke@435:   // the other for concrete method implementations and overrides.
duke@435:   bool doing_subtype_search() {
duke@435:     return _name == NULL;
duke@435:   }
duke@435: 
duke@435:   int num_participants() { return _num_participants; }
coleenp@4037:   Klass* participant(int n) {
duke@435:     assert((uint)n <= (uint)_num_participants, "oob");
duke@435:     return _participants[n];
duke@435:   }
duke@435: 
duke@435:   // Note:  If n==num_participants, returns NULL.
coleenp@4037:   Method* found_method(int n) {
duke@435:     assert((uint)n <= (uint)_num_participants, "oob");
coleenp@4037:     Method* fm = _found_methods[n];
duke@435:     assert(n == _num_participants || fm != NULL, "proper usage");
duke@435:     assert(fm == NULL || fm->method_holder() == _participants[n], "sanity");
duke@435:     return fm;
duke@435:   }
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   // Assert that m is inherited into ctxk, without intervening overrides.
duke@435:   // (May return true even if this is not true, in corner cases where we punt.)
coleenp@4037:   bool check_method_context(Klass* ctxk, Method* m) {
duke@435:     if (m->method_holder() == ctxk)
duke@435:       return true;  // Quick win.
duke@435:     if (m->is_private())
duke@435:       return false; // Quick lose.  Should not happen.
duke@435:     if (!(m->is_public() || m->is_protected()))
duke@435:       // The override story is complex when packages get involved.
duke@435:       return true;  // Must punt the assertion to true.
hseigel@4278:     Klass* k = ctxk;
coleenp@4037:     Method* lm = k->lookup_method(m->name(), m->signature());
duke@435:     if (lm == NULL && k->oop_is_instance()) {
acorn@5848:       // It might be an interface method
acorn@5848:         lm = ((InstanceKlass*)k)->lookup_method_in_ordered_interfaces(m->name(),
duke@435:                                                                 m->signature());
duke@435:     }
duke@435:     if (lm == m)
duke@435:       // Method m is inherited into ctxk.
duke@435:       return true;
duke@435:     if (lm != NULL) {
never@3256:       if (!(lm->is_public() || lm->is_protected())) {
duke@435:         // Method is [package-]private, so the override story is complex.
duke@435:         return true;  // Must punt the assertion to true.
never@3256:       }
never@3256:       if (lm->is_static()) {
never@3256:         // Static methods don't override non-static so punt
never@3256:         return true;
never@3256:       }
duke@435:       if (   !Dependencies::is_concrete_method(lm)
duke@435:           && !Dependencies::is_concrete_method(m)
coleenp@4251:           && lm->method_holder()->is_subtype_of(m->method_holder()))
duke@435:         // Method m is overridden by lm, but both are non-concrete.
duke@435:         return true;
duke@435:     }
duke@435:     ResourceMark rm;
duke@435:     tty->print_cr("Dependency method not found in the associated context:");
hseigel@4278:     tty->print_cr("  context = %s", ctxk->external_name());
duke@435:     tty->print(   "  method = "); m->print_short_name(tty); tty->cr();
duke@435:     if (lm != NULL) {
duke@435:       tty->print( "  found = "); lm->print_short_name(tty); tty->cr();
duke@435:     }
duke@435:     return false;
duke@435:   }
duke@435: #endif
duke@435: 
coleenp@4037:   void add_participant(Klass* participant) {
duke@435:     assert(_num_participants + _record_witnesses < PARTICIPANT_LIMIT, "oob");
duke@435:     int np = _num_participants++;
duke@435:     _participants[np] = participant;
duke@435:     _participants[np+1] = NULL;
duke@435:     _found_methods[np+1] = NULL;
duke@435:   }
duke@435: 
duke@435:   void record_witnesses(int add) {
duke@435:     if (add > PARTICIPANT_LIMIT)  add = PARTICIPANT_LIMIT;
duke@435:     assert(_num_participants + add < PARTICIPANT_LIMIT, "oob");
duke@435:     _record_witnesses = add;
duke@435:   }
duke@435: 
coleenp@4037:   bool is_witness(Klass* k) {
duke@435:     if (doing_subtype_search()) {
duke@435:       return Dependencies::is_concrete_klass(k);
duke@435:     } else {
coleenp@4037:       Method* m = InstanceKlass::cast(k)->find_method(_name, _signature);
duke@435:       if (m == NULL || !Dependencies::is_concrete_method(m))  return false;
duke@435:       _found_methods[_num_participants] = m;
duke@435:       // Note:  If add_participant(k) is called,
duke@435:       // the method m will already be memoized for it.
duke@435:       return true;
duke@435:     }
duke@435:   }
duke@435: 
coleenp@4037:   bool is_participant(Klass* k) {
duke@435:     if (k == _participants[0]) {
duke@435:       return true;
duke@435:     } else if (_num_participants <= 1) {
duke@435:       return false;
duke@435:     } else {
duke@435:       return in_list(k, &_participants[1]);
duke@435:     }
duke@435:   }
coleenp@4037:   bool ignore_witness(Klass* witness) {
duke@435:     if (_record_witnesses == 0) {
duke@435:       return false;
duke@435:     } else {
duke@435:       --_record_witnesses;
duke@435:       add_participant(witness);
duke@435:       return true;
duke@435:     }
duke@435:   }
coleenp@4037:   static bool in_list(Klass* x, Klass** list) {
duke@435:     for (int i = 0; ; i++) {
coleenp@4037:       Klass* y = list[i];
duke@435:       if (y == NULL)  break;
duke@435:       if (y == x)  return true;
duke@435:     }
duke@435:     return false;  // not in list
duke@435:   }
duke@435: 
duke@435:  private:
duke@435:   // the actual search method:
coleenp@4037:   Klass* find_witness_anywhere(Klass* context_type,
duke@435:                                  bool participants_hide_witnesses,
duke@435:                                  bool top_level_call = true);
duke@435:   // the spot-checking version:
coleenp@4037:   Klass* find_witness_in(KlassDepChange& changes,
coleenp@4037:                          Klass* context_type,
duke@435:                            bool participants_hide_witnesses);
duke@435:  public:
coleenp@4037:   Klass* find_witness_subtype(Klass* context_type, KlassDepChange* changes = NULL) {
duke@435:     assert(doing_subtype_search(), "must set up a subtype search");
duke@435:     // When looking for unexpected concrete types,
duke@435:     // do not look beneath expected ones.
duke@435:     const bool participants_hide_witnesses = true;
duke@435:     // CX > CC > C' is OK, even if C' is new.
duke@435:     // CX > { CC,  C' } is not OK if C' is new, and C' is the witness.
duke@435:     if (changes != NULL) {
duke@435:       return find_witness_in(*changes, context_type, participants_hide_witnesses);
duke@435:     } else {
duke@435:       return find_witness_anywhere(context_type, participants_hide_witnesses);
duke@435:     }
duke@435:   }
coleenp@4037:   Klass* find_witness_definer(Klass* context_type, KlassDepChange* changes = NULL) {
duke@435:     assert(!doing_subtype_search(), "must set up a method definer search");
duke@435:     // When looking for unexpected concrete methods,
duke@435:     // look beneath expected ones, to see if there are overrides.
duke@435:     const bool participants_hide_witnesses = true;
duke@435:     // CX.m > CC.m > C'.m is not OK, if C'.m is new, and C' is the witness.
duke@435:     if (changes != NULL) {
duke@435:       return find_witness_in(*changes, context_type, !participants_hide_witnesses);
duke@435:     } else {
duke@435:       return find_witness_anywhere(context_type, !participants_hide_witnesses);
duke@435:     }
duke@435:   }
duke@435: };
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: static int deps_find_witness_calls = 0;
duke@435: static int deps_find_witness_steps = 0;
duke@435: static int deps_find_witness_recursions = 0;
duke@435: static int deps_find_witness_singles = 0;
duke@435: static int deps_find_witness_print = 0; // set to -1 to force a final print
duke@435: static bool count_find_witness_calls() {
duke@435:   if (TraceDependencies || LogCompilation) {
duke@435:     int pcount = deps_find_witness_print + 1;
duke@435:     bool final_stats      = (pcount == 0);
duke@435:     bool initial_call     = (pcount == 1);
duke@435:     bool occasional_print = ((pcount & ((1<<10) - 1)) == 0);
duke@435:     if (pcount < 0)  pcount = 1; // crude overflow protection
duke@435:     deps_find_witness_print = pcount;
duke@435:     if (VerifyDependencies && initial_call) {
duke@435:       tty->print_cr("Warning:  TraceDependencies results may be inflated by VerifyDependencies");
duke@435:     }
duke@435:     if (occasional_print || final_stats) {
duke@435:       // Every now and then dump a little info about dependency searching.
duke@435:       if (xtty != NULL) {
kvn@1641:        ttyLocker ttyl;
kvn@1641:        xtty->elem("deps_find_witness calls='%d' steps='%d' recursions='%d' singles='%d'",
duke@435:                    deps_find_witness_calls,
duke@435:                    deps_find_witness_steps,
duke@435:                    deps_find_witness_recursions,
duke@435:                    deps_find_witness_singles);
duke@435:       }
duke@435:       if (final_stats || (TraceDependencies && WizardMode)) {
kvn@1641:         ttyLocker ttyl;
duke@435:         tty->print_cr("Dependency check (find_witness) "
duke@435:                       "calls=%d, steps=%d (avg=%.1f), recursions=%d, singles=%d",
duke@435:                       deps_find_witness_calls,
duke@435:                       deps_find_witness_steps,
duke@435:                       (double)deps_find_witness_steps / deps_find_witness_calls,
duke@435:                       deps_find_witness_recursions,
duke@435:                       deps_find_witness_singles);
duke@435:       }
duke@435:     }
duke@435:     return true;
duke@435:   }
duke@435:   return false;
duke@435: }
duke@435: #else
duke@435: #define count_find_witness_calls() (0)
duke@435: #endif //PRODUCT
duke@435: 
duke@435: 
coleenp@4037: Klass* ClassHierarchyWalker::find_witness_in(KlassDepChange& changes,
coleenp@4037:                                                Klass* context_type,
duke@435:                                                bool participants_hide_witnesses) {
duke@435:   assert(changes.involves_context(context_type), "irrelevant dependency");
coleenp@4037:   Klass* new_type = changes.new_type();
duke@435: 
ccheung@5259:   (void)count_find_witness_calls();
duke@435:   NOT_PRODUCT(deps_find_witness_singles++);
duke@435: 
duke@435:   // Current thread must be in VM (not native mode, as in CI):
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   // Must not move the class hierarchy during this check:
duke@435:   assert_locked_or_safepoint(Compile_lock);
duke@435: 
coleenp@4037:   int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
jrose@465:   if (nof_impls > 1) {
jrose@465:     // Avoid this case: *I.m > { A.m, C }; B.m > C
jrose@465:     // %%% Until this is fixed more systematically, bail out.
jrose@465:     // See corresponding comment in find_witness_anywhere.
jrose@465:     return context_type;
jrose@465:   }
jrose@465: 
duke@435:   assert(!is_participant(new_type), "only old classes are participants");
duke@435:   if (participants_hide_witnesses) {
duke@435:     // If the new type is a subtype of a participant, we are done.
duke@435:     for (int i = 0; i < num_participants(); i++) {
coleenp@4037:       Klass* part = participant(i);
duke@435:       if (part == NULL)  continue;
hseigel@4278:       assert(changes.involves_context(part) == new_type->is_subtype_of(part),
duke@435:              "correct marking of participants, b/c new_type is unique");
duke@435:       if (changes.involves_context(part)) {
duke@435:         // new guy is protected from this check by previous participant
duke@435:         return NULL;
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   if (is_witness(new_type) &&
duke@435:       !ignore_witness(new_type)) {
duke@435:     return new_type;
duke@435:   }
duke@435: 
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: 
duke@435: // Walk hierarchy under a context type, looking for unexpected types.
duke@435: // Do not report participant types, and recursively walk beneath
duke@435: // them only if participants_hide_witnesses is false.
duke@435: // If top_level_call is false, skip testing the context type,
duke@435: // because the caller has already considered it.
coleenp@4037: Klass* ClassHierarchyWalker::find_witness_anywhere(Klass* context_type,
duke@435:                                                      bool participants_hide_witnesses,
duke@435:                                                      bool top_level_call) {
duke@435:   // Current thread must be in VM (not native mode, as in CI):
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   // Must not move the class hierarchy during this check:
duke@435:   assert_locked_or_safepoint(Compile_lock);
duke@435: 
duke@435:   bool do_counts = count_find_witness_calls();
duke@435: 
duke@435:   // Check the root of the sub-hierarchy first.
duke@435:   if (top_level_call) {
duke@435:     if (do_counts) {
duke@435:       NOT_PRODUCT(deps_find_witness_calls++);
duke@435:       NOT_PRODUCT(deps_find_witness_steps++);
duke@435:     }
duke@435:     if (is_participant(context_type)) {
duke@435:       if (participants_hide_witnesses)  return NULL;
duke@435:       // else fall through to search loop...
duke@435:     } else if (is_witness(context_type) && !ignore_witness(context_type)) {
duke@435:       // The context is an abstract class or interface, to start with.
duke@435:       return context_type;
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Now we must check each implementor and each subclass.
duke@435:   // Use a short worklist to avoid blowing the stack.
duke@435:   // Each worklist entry is a *chain* of subklass siblings to process.
coleenp@4037:   const int CHAINMAX = 100;  // >= 1 + InstanceKlass::implementors_limit
duke@435:   Klass* chains[CHAINMAX];
duke@435:   int    chaini = 0;  // index into worklist
duke@435:   Klass* chain;       // scratch variable
duke@435: #define ADD_SUBCLASS_CHAIN(k)                     {  \
duke@435:     assert(chaini < CHAINMAX, "oob");                \
coleenp@4037:     chain = InstanceKlass::cast(k)->subklass();      \
duke@435:     if (chain != NULL)  chains[chaini++] = chain;    }
duke@435: 
duke@435:   // Look for non-abstract subclasses.
duke@435:   // (Note:  Interfaces do not have subclasses.)
duke@435:   ADD_SUBCLASS_CHAIN(context_type);
duke@435: 
duke@435:   // If it is an interface, search its direct implementors.
duke@435:   // (Their subclasses are additional indirect implementors.
coleenp@4037:   // See InstanceKlass::add_implementor.)
duke@435:   // (Note:  nof_implementors is always zero for non-interfaces.)
coleenp@4037:   int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
duke@435:   if (nof_impls > 1) {
duke@435:     // Avoid this case: *I.m > { A.m, C }; B.m > C
duke@435:     // Here, I.m has 2 concrete implementations, but m appears unique
duke@435:     // as A.m, because the search misses B.m when checking C.
duke@435:     // The inherited method B.m was getting missed by the walker
duke@435:     // when interface 'I' was the starting point.
duke@435:     // %%% Until this is fixed more systematically, bail out.
duke@435:     // (Old CHA had the same limitation.)
duke@435:     return context_type;
duke@435:   }
jiangli@3701:   if (nof_impls > 0) {
coleenp@4037:     Klass* impl = InstanceKlass::cast(context_type)->implementor();
jiangli@3701:     assert(impl != NULL, "just checking");
jiangli@3701:     // If impl is the same as the context_type, then more than one
jiangli@3701:     // implementor has seen. No exact info in this case.
jiangli@3701:     if (impl == context_type) {
duke@435:       return context_type;  // report an inexact witness to this sad affair
duke@435:     }
duke@435:     if (do_counts)
duke@435:       { NOT_PRODUCT(deps_find_witness_steps++); }
duke@435:     if (is_participant(impl)) {
jiangli@3701:       if (!participants_hide_witnesses) {
jiangli@3701:         ADD_SUBCLASS_CHAIN(impl);
jiangli@3701:       }
duke@435:     } else if (is_witness(impl) && !ignore_witness(impl)) {
duke@435:       return impl;
jiangli@3701:     } else {
jiangli@3701:       ADD_SUBCLASS_CHAIN(impl);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Recursively process each non-trivial sibling chain.
duke@435:   while (chaini > 0) {
duke@435:     Klass* chain = chains[--chaini];
coleenp@4037:     for (Klass* sub = chain; sub != NULL; sub = sub->next_sibling()) {
duke@435:       if (do_counts) { NOT_PRODUCT(deps_find_witness_steps++); }
duke@435:       if (is_participant(sub)) {
duke@435:         if (participants_hide_witnesses)  continue;
duke@435:         // else fall through to process this guy's subclasses
duke@435:       } else if (is_witness(sub) && !ignore_witness(sub)) {
duke@435:         return sub;
duke@435:       }
duke@435:       if (chaini < (VerifyDependencies? 2: CHAINMAX)) {
duke@435:         // Fast path.  (Partially disabled if VerifyDependencies.)
duke@435:         ADD_SUBCLASS_CHAIN(sub);
duke@435:       } else {
duke@435:         // Worklist overflow.  Do a recursive call.  Should be rare.
duke@435:         // The recursive call will have its own worklist, of course.
duke@435:         // (Note that sub has already been tested, so that there is
duke@435:         // no need for the recursive call to re-test.  That's handy,
duke@435:         // since the recursive call sees sub as the context_type.)
duke@435:         if (do_counts) { NOT_PRODUCT(deps_find_witness_recursions++); }
coleenp@4037:         Klass* witness = find_witness_anywhere(sub,
duke@435:                                                  participants_hide_witnesses,
duke@435:                                                  /*top_level_call=*/ false);
duke@435:         if (witness != NULL)  return witness;
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // No witness found.  The dependency remains unbroken.
duke@435:   return NULL;
duke@435: #undef ADD_SUBCLASS_CHAIN
duke@435: }
duke@435: 
duke@435: 
coleenp@4037: bool Dependencies::is_concrete_klass(Klass* k) {
hseigel@4278:   if (k->is_abstract())  return false;
duke@435:   // %%% We could treat classes which are concrete but
duke@435:   // have not yet been instantiated as virtually abstract.
duke@435:   // This would require a deoptimization barrier on first instantiation.
duke@435:   //if (k->is_not_instantiated())  return false;
duke@435:   return true;
duke@435: }
duke@435: 
coleenp@4037: bool Dependencies::is_concrete_method(Method* m) {
never@3256:   // Statics are irrelevant to virtual call sites.
never@3256:   if (m->is_static())  return false;
never@3256: 
never@3256:   // We could also return false if m does not yet appear to be
never@3256:   // executed, if the VM version supports this distinction also.
kamg@4245:   return !m->is_abstract() &&
kamg@4245:          !InstanceKlass::cast(m->method_holder())->is_interface();
kamg@4245:          // TODO: investigate whether default methods should be
kamg@4245:          // considered as "concrete" in this situation.  For now they
kamg@4245:          // are not.
duke@435: }
duke@435: 
duke@435: 
duke@435: Klass* Dependencies::find_finalizable_subclass(Klass* k) {
duke@435:   if (k->is_interface())  return NULL;
duke@435:   if (k->has_finalizer()) return k;
duke@435:   k = k->subklass();
duke@435:   while (k != NULL) {
duke@435:     Klass* result = find_finalizable_subclass(k);
duke@435:     if (result != NULL) return result;
duke@435:     k = k->next_sibling();
duke@435:   }
duke@435:   return NULL;
duke@435: }
duke@435: 
duke@435: 
duke@435: bool Dependencies::is_concrete_klass(ciInstanceKlass* k) {
duke@435:   if (k->is_abstract())  return false;
never@3256:   // We could also return false if k does not yet appear to be
duke@435:   // instantiated, if the VM version supports this distinction also.
duke@435:   //if (k->is_not_instantiated())  return false;
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: bool Dependencies::is_concrete_method(ciMethod* m) {
duke@435:   // Statics are irrelevant to virtual call sites.
duke@435:   if (m->is_static())  return false;
duke@435: 
never@3256:   // We could also return false if m does not yet appear to be
duke@435:   // executed, if the VM version supports this distinction also.
duke@435:   return !m->is_abstract();
duke@435: }
duke@435: 
duke@435: 
duke@435: bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) {
duke@435:   return k->has_finalizable_subclass();
duke@435: }
duke@435: 
duke@435: 
duke@435: // Any use of the contents (bytecodes) of a method must be
duke@435: // marked by an "evol_method" dependency, if those contents
duke@435: // can change.  (Note: A method is always dependent on itself.)
coleenp@4037: Klass* Dependencies::check_evol_method(Method* m) {
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   // Did somebody do a JVMTI RedefineClasses while our backs were turned?
duke@435:   // Or is there a now a breakpoint?
duke@435:   // (Assumes compiled code cannot handle bkpts; change if UseFastBreakpoints.)
duke@435:   if (m->is_old()
duke@435:       || m->number_of_breakpoints() > 0) {
duke@435:     return m->method_holder();
duke@435:   } else {
duke@435:     return NULL;
duke@435:   }
duke@435: }
duke@435: 
duke@435: // This is a strong assertion:  It is that the given type
duke@435: // has no subtypes whatever.  It is most useful for
duke@435: // optimizing checks on reflected types or on array types.
duke@435: // (Checks on types which are derived from real instances
duke@435: // can be optimized more strongly than this, because we
duke@435: // know that the checked type comes from a concrete type,
duke@435: // and therefore we can disregard abstract types.)
coleenp@4037: Klass* Dependencies::check_leaf_type(Klass* ctxk) {
duke@435:   assert(must_be_in_vm(), "raw oops here");
duke@435:   assert_locked_or_safepoint(Compile_lock);
coleenp@4037:   InstanceKlass* ctx = InstanceKlass::cast(ctxk);
duke@435:   Klass* sub = ctx->subklass();
duke@435:   if (sub != NULL) {
coleenp@4037:     return sub;
duke@435:   } else if (ctx->nof_implementors() != 0) {
duke@435:     // if it is an interface, it must be unimplemented
duke@435:     // (if it is not an interface, nof_implementors is always zero)
coleenp@4037:     Klass* impl = ctx->implementor();
jiangli@3701:     assert(impl != NULL, "must be set");
jiangli@3701:     return impl;
duke@435:   } else {
duke@435:     return NULL;
duke@435:   }
duke@435: }
duke@435: 
duke@435: // Test the assertion that conck is the only concrete subtype* of ctxk.
duke@435: // The type conck itself is allowed to have have further concrete subtypes.
duke@435: // This allows the compiler to narrow occurrences of ctxk by conck,
duke@435: // when dealing with the types of actual instances.
coleenp@4037: Klass* Dependencies::check_abstract_with_unique_concrete_subtype(Klass* ctxk,
coleenp@4037:                                                                    Klass* conck,
twisti@3050:                                                                    KlassDepChange* changes) {
duke@435:   ClassHierarchyWalker wf(conck);
duke@435:   return wf.find_witness_subtype(ctxk, changes);
duke@435: }
duke@435: 
duke@435: // If a non-concrete class has no concrete subtypes, it is not (yet)
duke@435: // instantiatable.  This can allow the compiler to make some paths go
duke@435: // dead, if they are gated by a test of the type.
coleenp@4037: Klass* Dependencies::check_abstract_with_no_concrete_subtype(Klass* ctxk,
twisti@3050:                                                                KlassDepChange* changes) {
duke@435:   // Find any concrete subtype, with no participants:
duke@435:   ClassHierarchyWalker wf;
duke@435:   return wf.find_witness_subtype(ctxk, changes);
duke@435: }
duke@435: 
duke@435: 
duke@435: // If a concrete class has no concrete subtypes, it can always be
duke@435: // exactly typed.  This allows the use of a cheaper type test.
coleenp@4037: Klass* Dependencies::check_concrete_with_no_concrete_subtype(Klass* ctxk,
twisti@3050:                                                                KlassDepChange* changes) {
duke@435:   // Find any concrete subtype, with only the ctxk as participant:
duke@435:   ClassHierarchyWalker wf(ctxk);
duke@435:   return wf.find_witness_subtype(ctxk, changes);
duke@435: }
duke@435: 
duke@435: 
duke@435: // Find the unique concrete proper subtype of ctxk, or NULL if there
duke@435: // is more than one concrete proper subtype.  If there are no concrete
duke@435: // proper subtypes, return ctxk itself, whether it is concrete or not.
duke@435: // The returned subtype is allowed to have have further concrete subtypes.
duke@435: // That is, return CC1 for CX > CC1 > CC2, but NULL for CX > { CC1, CC2 }.
coleenp@4037: Klass* Dependencies::find_unique_concrete_subtype(Klass* ctxk) {
duke@435:   ClassHierarchyWalker wf(ctxk);   // Ignore ctxk when walking.
duke@435:   wf.record_witnesses(1);          // Record one other witness when walking.
coleenp@4037:   Klass* wit = wf.find_witness_subtype(ctxk);
duke@435:   if (wit != NULL)  return NULL;   // Too many witnesses.
coleenp@4037:   Klass* conck = wf.participant(0);
duke@435:   if (conck == NULL) {
duke@435: #ifndef PRODUCT
duke@435:     // Make sure the dependency mechanism will pass this discovery:
duke@435:     if (VerifyDependencies) {
duke@435:       // Turn off dependency tracing while actually testing deps.
duke@435:       FlagSetting fs(TraceDependencies, false);
duke@435:       if (!Dependencies::is_concrete_klass(ctxk)) {
duke@435:         guarantee(NULL ==
duke@435:                   (void *)check_abstract_with_no_concrete_subtype(ctxk),
duke@435:                   "verify dep.");
duke@435:       } else {
duke@435:         guarantee(NULL ==
duke@435:                   (void *)check_concrete_with_no_concrete_subtype(ctxk),
duke@435:                   "verify dep.");
duke@435:       }
duke@435:     }
duke@435: #endif //PRODUCT
duke@435:     return ctxk;                   // Return ctxk as a flag for "no subtypes".
duke@435:   } else {
duke@435: #ifndef PRODUCT
duke@435:     // Make sure the dependency mechanism will pass this discovery:
duke@435:     if (VerifyDependencies) {
duke@435:       // Turn off dependency tracing while actually testing deps.
duke@435:       FlagSetting fs(TraceDependencies, false);
duke@435:       if (!Dependencies::is_concrete_klass(ctxk)) {
duke@435:         guarantee(NULL == (void *)
duke@435:                   check_abstract_with_unique_concrete_subtype(ctxk, conck),
duke@435:                   "verify dep.");
duke@435:       }
duke@435:     }
duke@435: #endif //PRODUCT
duke@435:     return conck;
duke@435:   }
duke@435: }
duke@435: 
duke@435: // Test the assertion that the k[12] are the only concrete subtypes of ctxk,
duke@435: // except possibly for further subtypes of k[12] themselves.
duke@435: // The context type must be abstract.  The types k1 and k2 are themselves
duke@435: // allowed to have further concrete subtypes.
coleenp@4037: Klass* Dependencies::check_abstract_with_exclusive_concrete_subtypes(
coleenp@4037:                                                 Klass* ctxk,
coleenp@4037:                                                 Klass* k1,
coleenp@4037:                                                 Klass* k2,
twisti@3050:                                                 KlassDepChange* changes) {
duke@435:   ClassHierarchyWalker wf;
duke@435:   wf.add_participant(k1);
duke@435:   wf.add_participant(k2);
duke@435:   return wf.find_witness_subtype(ctxk, changes);
duke@435: }
duke@435: 
duke@435: // Search ctxk for concrete implementations.  If there are klen or fewer,
duke@435: // pack them into the given array and return the number.
duke@435: // Otherwise, return -1, meaning the given array would overflow.
duke@435: // (Note that a return of 0 means there are exactly no concrete subtypes.)
duke@435: // In this search, if ctxk is concrete, it will be reported alone.
duke@435: // For any type CC reported, no proper subtypes of CC will be reported.
coleenp@4037: int Dependencies::find_exclusive_concrete_subtypes(Klass* ctxk,
duke@435:                                                    int klen,
coleenp@4037:                                                    Klass* karray[]) {
duke@435:   ClassHierarchyWalker wf;
duke@435:   wf.record_witnesses(klen);
coleenp@4037:   Klass* wit = wf.find_witness_subtype(ctxk);
duke@435:   if (wit != NULL)  return -1;  // Too many witnesses.
duke@435:   int num = wf.num_participants();
duke@435:   assert(num <= klen, "oob");
duke@435:   // Pack the result array with the good news.
duke@435:   for (int i = 0; i < num; i++)
duke@435:     karray[i] = wf.participant(i);
duke@435: #ifndef PRODUCT
duke@435:   // Make sure the dependency mechanism will pass this discovery:
duke@435:   if (VerifyDependencies) {
duke@435:     // Turn off dependency tracing while actually testing deps.
duke@435:     FlagSetting fs(TraceDependencies, false);
duke@435:     switch (Dependencies::is_concrete_klass(ctxk)? -1: num) {
duke@435:     case -1: // ctxk was itself concrete
duke@435:       guarantee(num == 1 && karray[0] == ctxk, "verify dep.");
duke@435:       break;
duke@435:     case 0:
duke@435:       guarantee(NULL == (void *)check_abstract_with_no_concrete_subtype(ctxk),
duke@435:                 "verify dep.");
duke@435:       break;
duke@435:     case 1:
duke@435:       guarantee(NULL == (void *)
duke@435:                 check_abstract_with_unique_concrete_subtype(ctxk, karray[0]),
duke@435:                 "verify dep.");
duke@435:       break;
duke@435:     case 2:
duke@435:       guarantee(NULL == (void *)
duke@435:                 check_abstract_with_exclusive_concrete_subtypes(ctxk,
duke@435:                                                                 karray[0],
duke@435:                                                                 karray[1]),
duke@435:                 "verify dep.");
duke@435:       break;
duke@435:     default:
duke@435:       ShouldNotReachHere();  // klen > 2 yet supported
duke@435:     }
duke@435:   }
duke@435: #endif //PRODUCT
duke@435:   return num;
duke@435: }
duke@435: 
duke@435: // If a class (or interface) has a unique concrete method uniqm, return NULL.
duke@435: // Otherwise, return a class that contains an interfering method.
coleenp@4037: Klass* Dependencies::check_unique_concrete_method(Klass* ctxk, Method* uniqm,
twisti@3050:                                                     KlassDepChange* changes) {
duke@435:   // Here is a missing optimization:  If uniqm->is_final(),
duke@435:   // we don't really need to search beneath it for overrides.
duke@435:   // This is probably not important, since we don't use dependencies
duke@435:   // to track final methods.  (They can't be "definalized".)
duke@435:   ClassHierarchyWalker wf(uniqm->method_holder(), uniqm);
duke@435:   return wf.find_witness_definer(ctxk, changes);
duke@435: }
duke@435: 
duke@435: // Find the set of all non-abstract methods under ctxk that match m.
duke@435: // (The method m must be defined or inherited in ctxk.)
duke@435: // Include m itself in the set, unless it is abstract.
duke@435: // If this set has exactly one element, return that element.
coleenp@4037: Method* Dependencies::find_unique_concrete_method(Klass* ctxk, Method* m) {
duke@435:   ClassHierarchyWalker wf(m);
duke@435:   assert(wf.check_method_context(ctxk, m), "proper context");
duke@435:   wf.record_witnesses(1);
coleenp@4037:   Klass* wit = wf.find_witness_definer(ctxk);
duke@435:   if (wit != NULL)  return NULL;  // Too many witnesses.
coleenp@4037:   Method* fm = wf.found_method(0);  // Will be NULL if num_parts == 0.
duke@435:   if (Dependencies::is_concrete_method(m)) {
duke@435:     if (fm == NULL) {
duke@435:       // It turns out that m was always the only implementation.
duke@435:       fm = m;
duke@435:     } else if (fm != m) {
duke@435:       // Two conflicting implementations after all.
duke@435:       // (This can happen if m is inherited into ctxk and fm overrides it.)
duke@435:       return NULL;
duke@435:     }
duke@435:   }
duke@435: #ifndef PRODUCT
duke@435:   // Make sure the dependency mechanism will pass this discovery:
duke@435:   if (VerifyDependencies && fm != NULL) {
duke@435:     guarantee(NULL == (void *)check_unique_concrete_method(ctxk, fm),
duke@435:               "verify dep.");
duke@435:   }
duke@435: #endif //PRODUCT
duke@435:   return fm;
duke@435: }
duke@435: 
coleenp@4037: Klass* Dependencies::check_exclusive_concrete_methods(Klass* ctxk,
coleenp@4037:                                                         Method* m1,
coleenp@4037:                                                         Method* m2,
twisti@3050:                                                         KlassDepChange* changes) {
duke@435:   ClassHierarchyWalker wf(m1);
duke@435:   wf.add_participant(m1->method_holder());
duke@435:   wf.add_participant(m2->method_holder());
duke@435:   return wf.find_witness_definer(ctxk, changes);
duke@435: }
duke@435: 
duke@435: // Find the set of all non-abstract methods under ctxk that match m[0].
duke@435: // (The method m[0] must be defined or inherited in ctxk.)
duke@435: // Include m itself in the set, unless it is abstract.
duke@435: // Fill the given array m[0..(mlen-1)] with this set, and return the length.
duke@435: // (The length may be zero if no concrete methods are found anywhere.)
duke@435: // If there are too many concrete methods to fit in marray, return -1.
coleenp@4037: int Dependencies::find_exclusive_concrete_methods(Klass* ctxk,
duke@435:                                                   int mlen,
coleenp@4037:                                                   Method* marray[]) {
coleenp@4037:   Method* m0 = marray[0];
duke@435:   ClassHierarchyWalker wf(m0);
duke@435:   assert(wf.check_method_context(ctxk, m0), "proper context");
duke@435:   wf.record_witnesses(mlen);
duke@435:   bool participants_hide_witnesses = true;
coleenp@4037:   Klass* wit = wf.find_witness_definer(ctxk);
duke@435:   if (wit != NULL)  return -1;  // Too many witnesses.
duke@435:   int num = wf.num_participants();
duke@435:   assert(num <= mlen, "oob");
duke@435:   // Keep track of whether m is also part of the result set.
duke@435:   int mfill = 0;
duke@435:   assert(marray[mfill] == m0, "sanity");
duke@435:   if (Dependencies::is_concrete_method(m0))
duke@435:     mfill++;  // keep m0 as marray[0], the first result
duke@435:   for (int i = 0; i < num; i++) {
coleenp@4037:     Method* fm = wf.found_method(i);
duke@435:     if (fm == m0)  continue;  // Already put this guy in the list.
duke@435:     if (mfill == mlen) {
duke@435:       return -1;              // Oops.  Too many methods after all!
duke@435:     }
duke@435:     marray[mfill++] = fm;
duke@435:   }
duke@435: #ifndef PRODUCT
duke@435:   // Make sure the dependency mechanism will pass this discovery:
duke@435:   if (VerifyDependencies) {
duke@435:     // Turn off dependency tracing while actually testing deps.
duke@435:     FlagSetting fs(TraceDependencies, false);
duke@435:     switch (mfill) {
duke@435:     case 1:
duke@435:       guarantee(NULL == (void *)check_unique_concrete_method(ctxk, marray[0]),
duke@435:                 "verify dep.");
duke@435:       break;
duke@435:     case 2:
duke@435:       guarantee(NULL == (void *)
duke@435:                 check_exclusive_concrete_methods(ctxk, marray[0], marray[1]),
duke@435:                 "verify dep.");
duke@435:       break;
duke@435:     default:
duke@435:       ShouldNotReachHere();  // mlen > 2 yet supported
duke@435:     }
duke@435:   }
duke@435: #endif //PRODUCT
duke@435:   return mfill;
duke@435: }
duke@435: 
duke@435: 
coleenp@4037: Klass* Dependencies::check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes) {
coleenp@4037:   Klass* search_at = ctxk;
duke@435:   if (changes != NULL)
coleenp@4037:     search_at = changes->new_type(); // just look at the new bit
coleenp@4037:   return find_finalizable_subclass(search_at);
duke@435: }
duke@435: 
duke@435: 
coleenp@4037: Klass* Dependencies::check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes) {
twisti@3050:   assert(call_site    ->is_a(SystemDictionary::CallSite_klass()),     "sanity");
twisti@3050:   assert(method_handle->is_a(SystemDictionary::MethodHandle_klass()), "sanity");
twisti@3050:   if (changes == NULL) {
twisti@3050:     // Validate all CallSites
twisti@3050:     if (java_lang_invoke_CallSite::target(call_site) != method_handle)
twisti@3094:       return call_site->klass();  // assertion failed
twisti@3050:   } else {
twisti@3050:     // Validate the given CallSite
twisti@3050:     if (call_site == changes->call_site() && java_lang_invoke_CallSite::target(call_site) != changes->method_handle()) {
twisti@3050:       assert(method_handle != changes->method_handle(), "must be");
twisti@3094:       return call_site->klass();  // assertion failed
twisti@3050:     }
twisti@3050:   }
twisti@3050:   return NULL;  // assertion still valid
twisti@3050: }
twisti@3050: 
twisti@3050: 
coleenp@4037: void Dependencies::DepStream::trace_and_log_witness(Klass* witness) {
twisti@3050:   if (witness != NULL) {
twisti@3050:     if (TraceDependencies) {
twisti@3050:       print_dependency(witness, /*verbose=*/ true);
twisti@3050:     }
twisti@3050:     // The following is a no-op unless logging is enabled:
twisti@3050:     log_dependency(witness);
twisti@3050:   }
twisti@3050: }
twisti@3050: 
twisti@3050: 
coleenp@4037: Klass* Dependencies::DepStream::check_klass_dependency(KlassDepChange* changes) {
duke@435:   assert_locked_or_safepoint(Compile_lock);
twisti@3050:   Dependencies::check_valid_dependency_type(type());
duke@435: 
coleenp@4037:   Klass* witness = NULL;
duke@435:   switch (type()) {
duke@435:   case evol_method:
duke@435:     witness = check_evol_method(method_argument(0));
duke@435:     break;
duke@435:   case leaf_type:
duke@435:     witness = check_leaf_type(context_type());
duke@435:     break;
duke@435:   case abstract_with_unique_concrete_subtype:
twisti@3050:     witness = check_abstract_with_unique_concrete_subtype(context_type(), type_argument(1), changes);
duke@435:     break;
duke@435:   case abstract_with_no_concrete_subtype:
twisti@3050:     witness = check_abstract_with_no_concrete_subtype(context_type(), changes);
duke@435:     break;
duke@435:   case concrete_with_no_concrete_subtype:
twisti@3050:     witness = check_concrete_with_no_concrete_subtype(context_type(), changes);
duke@435:     break;
duke@435:   case unique_concrete_method:
twisti@3050:     witness = check_unique_concrete_method(context_type(), method_argument(1), changes);
duke@435:     break;
duke@435:   case abstract_with_exclusive_concrete_subtypes_2:
twisti@3050:     witness = check_abstract_with_exclusive_concrete_subtypes(context_type(), type_argument(1), type_argument(2), changes);
duke@435:     break;
duke@435:   case exclusive_concrete_methods_2:
twisti@3050:     witness = check_exclusive_concrete_methods(context_type(), method_argument(1), method_argument(2), changes);
duke@435:     break;
duke@435:   case no_finalizable_subclasses:
twisti@3050:     witness = check_has_no_finalizable_subclasses(context_type(), changes);
duke@435:     break;
twisti@3050:   default:
duke@435:     witness = NULL;
duke@435:     break;
duke@435:   }
twisti@3050:   trace_and_log_witness(witness);
duke@435:   return witness;
duke@435: }
duke@435: 
duke@435: 
coleenp@4037: Klass* Dependencies::DepStream::check_call_site_dependency(CallSiteDepChange* changes) {
twisti@3050:   assert_locked_or_safepoint(Compile_lock);
twisti@3050:   Dependencies::check_valid_dependency_type(type());
duke@435: 
coleenp@4037:   Klass* witness = NULL;
twisti@3050:   switch (type()) {
twisti@3050:   case call_site_target_value:
coleenp@4037:     witness = check_call_site_target_value(argument_oop(0), argument_oop(1), changes);
twisti@3050:     break;
twisti@3050:   default:
twisti@3050:     witness = NULL;
twisti@3050:     break;
twisti@3050:   }
twisti@3050:   trace_and_log_witness(witness);
twisti@3050:   return witness;
duke@435: }
duke@435: 
duke@435: 
coleenp@4037: Klass* Dependencies::DepStream::spot_check_dependency_at(DepChange& changes) {
twisti@3050:   // Handle klass dependency
twisti@3050:   if (changes.is_klass_change() && changes.as_klass_change()->involves_context(context_type()))
twisti@3050:     return check_klass_dependency(changes.as_klass_change());
duke@435: 
twisti@3050:   // Handle CallSite dependency
twisti@3050:   if (changes.is_call_site_change())
twisti@3050:     return check_call_site_dependency(changes.as_call_site_change());
twisti@3050: 
twisti@3050:   // irrelevant dependency; skip it
twisti@3050:   return NULL;
twisti@3050: }
twisti@3050: 
twisti@3050: 
twisti@3050: void DepChange::print() {
twisti@3050:   int nsup = 0, nint = 0;
duke@435:   for (ContextStream str(*this); str.next(); ) {
coleenp@4037:     Klass* k = str.klass();
twisti@3050:     switch (str.change_type()) {
twisti@3050:     case Change_new_type:
coleenp@4037:       tty->print_cr("  dependee = %s", InstanceKlass::cast(k)->external_name());
twisti@3050:       break;
twisti@3050:     case Change_new_sub:
twisti@3050:       if (!WizardMode) {
twisti@3050:         ++nsup;
twisti@3050:       } else {
coleenp@4037:         tty->print_cr("  context super = %s", InstanceKlass::cast(k)->external_name());
twisti@3050:       }
twisti@3050:       break;
twisti@3050:     case Change_new_impl:
twisti@3050:       if (!WizardMode) {
twisti@3050:         ++nint;
twisti@3050:       } else {
coleenp@4037:         tty->print_cr("  context interface = %s", InstanceKlass::cast(k)->external_name());
twisti@3050:       }
twisti@3050:       break;
twisti@3050:     }
twisti@3050:   }
twisti@3050:   if (nsup + nint != 0) {
twisti@3050:     tty->print_cr("  context supers = %d, interfaces = %d", nsup, nint);
duke@435:   }
duke@435: }
duke@435: 
twisti@3050: void DepChange::ContextStream::start() {
coleenp@4037:   Klass* new_type = _changes.is_klass_change() ? _changes.as_klass_change()->new_type() : (Klass*) NULL;
twisti@3050:   _change_type = (new_type == NULL ? NO_CHANGE : Start_Klass);
twisti@3050:   _klass = new_type;
twisti@3050:   _ti_base = NULL;
twisti@3050:   _ti_index = 0;
twisti@3050:   _ti_limit = 0;
duke@435: }
duke@435: 
duke@435: bool DepChange::ContextStream::next() {
duke@435:   switch (_change_type) {
duke@435:   case Start_Klass:             // initial state; _klass is the new type
coleenp@4037:     _ti_base = InstanceKlass::cast(_klass)->transitive_interfaces();
duke@435:     _ti_index = 0;
duke@435:     _change_type = Change_new_type;
duke@435:     return true;
duke@435:   case Change_new_type:
duke@435:     // fall through:
duke@435:     _change_type = Change_new_sub;
duke@435:   case Change_new_sub:
sbohne@489:     // 6598190: brackets workaround Sun Studio C++ compiler bug 6629277
sbohne@489:     {
coleenp@4037:       _klass = InstanceKlass::cast(_klass)->super();
sbohne@489:       if (_klass != NULL) {
sbohne@489:         return true;
sbohne@489:       }
duke@435:     }
duke@435:     // else set up _ti_limit and fall through:
duke@435:     _ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length();
duke@435:     _change_type = Change_new_impl;
duke@435:   case Change_new_impl:
duke@435:     if (_ti_index < _ti_limit) {
coleenp@4037:       _klass = _ti_base->at(_ti_index++);
duke@435:       return true;
duke@435:     }
duke@435:     // fall through:
duke@435:     _change_type = NO_CHANGE;  // iterator is exhausted
duke@435:   case NO_CHANGE:
duke@435:     break;
duke@435:   default:
duke@435:     ShouldNotReachHere();
duke@435:   }
duke@435:   return false;
duke@435: }
duke@435: 
twisti@3050: void KlassDepChange::initialize() {
twisti@3050:   // entire transaction must be under this lock:
twisti@3050:   assert_lock_strong(Compile_lock);
twisti@3050: 
twisti@3050:   // Mark all dependee and all its superclasses
twisti@3050:   // Mark transitive interfaces
duke@435:   for (ContextStream str(*this); str.next(); ) {
coleenp@4037:     Klass* d = str.klass();
coleenp@4037:     assert(!InstanceKlass::cast(d)->is_marked_dependent(), "checking");
coleenp@4037:     InstanceKlass::cast(d)->set_is_marked_dependent(true);
duke@435:   }
twisti@3050: }
twisti@3050: 
twisti@3050: KlassDepChange::~KlassDepChange() {
twisti@3050:   // Unmark all dependee and all its superclasses
twisti@3050:   // Unmark transitive interfaces
twisti@3050:   for (ContextStream str(*this); str.next(); ) {
coleenp@4037:     Klass* d = str.klass();
coleenp@4037:     InstanceKlass::cast(d)->set_is_marked_dependent(false);
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: bool KlassDepChange::involves_context(Klass* k) {
hseigel@4278:   if (k == NULL || !k->oop_is_instance()) {
twisti@3050:     return false;
twisti@3050:   }
coleenp@4037:   InstanceKlass* ik = InstanceKlass::cast(k);
twisti@3050:   bool is_contained = ik->is_marked_dependent();
hseigel@4278:   assert(is_contained == new_type()->is_subtype_of(k),
twisti@3050:          "correct marking of potential context types");
twisti@3050:   return is_contained;
twisti@3050: }
twisti@3050: 
duke@435: #ifndef PRODUCT
duke@435: void Dependencies::print_statistics() {
duke@435:   if (deps_find_witness_print != 0) {
duke@435:     // Call one final time, to flush out the data.
duke@435:     deps_find_witness_print = -1;
duke@435:     count_find_witness_calls();
duke@435:   }
duke@435: }
duke@435: #endif