changeset 1830:d1896d1dda3e

6981788: GC map generator sometimes picks up the wrong kind of instruction operand Summary: Distinguish pool indexes from cache indexes in recently changed code. Reviewed-by: never
author jrose
date Sat, 30 Oct 2010 11:45:35 -0700
parents d2e35ffae982
children fff777a71346
files src/share/vm/oops/constantPoolOop.cpp src/share/vm/oops/constantPoolOop.hpp src/share/vm/oops/generateOopMap.cpp src/share/vm/oops/generateOopMap.hpp
diffstat 4 files changed, 23 insertions(+), 12 deletions(-) [+]
line wrap: on
line diff
--- a/src/share/vm/oops/constantPoolOop.cpp	Thu Oct 28 00:48:18 2010 -0700
+++ b/src/share/vm/oops/constantPoolOop.cpp	Sat Oct 30 11:45:35 2010 -0700
@@ -265,8 +265,7 @@
   int i = which;
   if (!uncached && cache() != NULL) {
     if (constantPoolCacheOopDesc::is_secondary_index(which)) {
-      // Invokedynamic indexes are always processed in native order
-      // so there is no question of reading a native u2 in Java order here.
+      // Invokedynamic index.
       int pool_index = cache()->main_entry_at(which)->constant_pool_index();
       if (tag_at(pool_index).is_invoke_dynamic())
         pool_index = invoke_dynamic_name_and_type_ref_index_at(pool_index);
--- a/src/share/vm/oops/constantPoolOop.hpp	Thu Oct 28 00:48:18 2010 -0700
+++ b/src/share/vm/oops/constantPoolOop.hpp	Sat Oct 30 11:45:35 2010 -0700
@@ -414,14 +414,19 @@
 
   // The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
   // name_and_type_ref_index_at) all expect to be passed indices obtained
-  // directly from the bytecode, and extracted according to java byte order.
+  // directly from the bytecode.
   // If the indices are meant to refer to fields or methods, they are
-  // actually potentially byte-swapped, rewritten constant pool cache indices.
+  // actually rewritten constant pool cache indices.
   // The routine remap_instruction_operand_from_cache manages the adjustment
   // of these values back to constant pool indices.
 
   // There are also "uncached" versions which do not adjust the operand index; see below.
 
+  // FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
+  // In a few cases (the verifier) there are uses before a cpcache has been built,
+  // which are handled by a dynamic check in remap_instruction_operand_from_cache.
+  // FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
+
   // Lookup for entries consisting of (klass_index, name_and_type index)
   klassOop klass_ref_at(int which, TRAPS);
   symbolOop klass_ref_at_noresolve(int which);
@@ -484,7 +489,7 @@
   static klassOop klass_ref_at_if_loaded_check(constantPoolHandle this_oop, int which, TRAPS);
 
   // Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
-  // future by other Java code. These take constant pool indices rather than possibly-byte-swapped
+  // future by other Java code. These take constant pool indices rather than
   // constant pool cache indices as do the peer methods above.
   symbolOop uncached_klass_ref_at_noresolve(int which);
   symbolOop uncached_name_ref_at(int which)                 { return impl_name_ref_at(which, true); }
--- a/src/share/vm/oops/generateOopMap.cpp	Thu Oct 28 00:48:18 2010 -0700
+++ b/src/share/vm/oops/generateOopMap.cpp	Sat Oct 30 11:45:35 2010 -0700
@@ -1254,7 +1254,7 @@
       case Bytecodes::_invokestatic:
       case Bytecodes::_invokedynamic:
       case Bytecodes::_invokeinterface:
-        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
+        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
         constantPoolOop cp    = method()->constants();
         int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
         int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
@@ -1286,7 +1286,7 @@
       case Bytecodes::_invokestatic:
       case Bytecodes::_invokedynamic:
       case Bytecodes::_invokeinterface:
-        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2();
+        int idx = currentBC->has_index_u4() ? currentBC->get_index_u4() : currentBC->get_index_u2_cpcache();
         constantPoolOop cp    = method()->constants();
         int nameAndTypeIdx    = cp->name_and_type_ref_index_at(idx);
         int signatureIdx      = cp->signature_ref_index_at(nameAndTypeIdx);
@@ -1356,8 +1356,8 @@
 
     case Bytecodes::_ldc2_w:            ppush(vvCTS);               break;
 
-    case Bytecodes::_ldc:               do_ldc(itr->get_index(),    itr->bci()); break;
-    case Bytecodes::_ldc_w:             do_ldc(itr->get_index_u2(), itr->bci()); break;
+    case Bytecodes::_ldc:               // fall through:
+    case Bytecodes::_ldc_w:             do_ldc(itr->bci());         break;
 
     case Bytecodes::_iload:
     case Bytecodes::_fload:             ppload(vCTS, itr->get_index()); break;
@@ -1829,9 +1829,16 @@
 
 
 
-void GenerateOopMap::do_ldc(int idx, int bci) {
+void GenerateOopMap::do_ldc(int bci) {
+  Bytecode_loadconstant* ldc = Bytecode_loadconstant_at(method(), bci);
   constantPoolOop cp  = method()->constants();
-  CellTypeState   cts = cp->is_pointer_entry(idx) ? CellTypeState::make_line_ref(bci) : valCTS;
+  BasicType       bt  = ldc->result_type();
+  CellTypeState   cts = (bt == T_OBJECT) ? CellTypeState::make_line_ref(bci) : valCTS;
+  // Make sure bt==T_OBJECT is the same as old code (is_pointer_entry).
+  // Note that CONSTANT_MethodHandle entries are u2 index pairs, not pointer-entries,
+  // and they are processed by _fast_aldc and the CP cache.
+  assert((ldc->has_cache_index() || cp->is_pointer_entry(ldc->pool_index()))
+         ? (bt == T_OBJECT) : true, "expected object type");
   ppush1(cts);
 }
 
--- a/src/share/vm/oops/generateOopMap.hpp	Thu Oct 28 00:48:18 2010 -0700
+++ b/src/share/vm/oops/generateOopMap.hpp	Sat Oct 30 11:45:35 2010 -0700
@@ -389,7 +389,7 @@
   void  pp                                  (CellTypeState *in, CellTypeState *out);
   void  pp_new_ref                          (CellTypeState *in, int bci);
   void  ppdupswap                           (int poplen, const char *out);
-  void  do_ldc                              (int idx, int bci);
+  void  do_ldc                              (int bci);
   void  do_astore                           (int idx);
   void  do_jsr                              (int delta);
   void  do_field                            (int is_get, int is_static, int idx, int bci);