1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
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 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_CODE_SCOPEDESC_HPP
 26 #define SHARE_CODE_SCOPEDESC_HPP
 27 
 28 #include "code/debugInfo.hpp"
 29 #include "code/pcDesc.hpp"
 30 #include "oops/method.hpp"
 31 #include "utilities/growableArray.hpp"
 32 
 33 // SimpleScopeDesc is used when all you need to extract from
 34 // a given pc,nmethod pair is a Method* and a bci. This is
 35 // quite a bit faster than allocating a full ScopeDesc, but
 36 // very limited in abilities.
 37 
 38 class SimpleScopeDesc : public StackObj {
 39  private:
 40   Method* _method;
 41   int _bci;
 42 
 43  public:
 44   SimpleScopeDesc(nmethod* code, address pc) {
 45     PcDesc* pc_desc = code->pc_desc_at(pc);
 46     assert(pc_desc != nullptr, "Must be able to find matching PcDesc");
 47     // save this here so we only have to look up the PcDesc once
 48     DebugInfoReadStream buffer(code, pc_desc->scope_decode_offset());
 49     int ignore_sender = buffer.read_int();
 50     _method           = buffer.read_method();
 51     _bci              = buffer.read_bci();
 52   }
 53 
 54   Method* method() { return _method; }
 55   int bci() { return _bci; }
 56 };
 57 
 58 // ScopeDescs contain the information that makes source-level debugging of
 59 // nmethods possible; each scopeDesc describes a method activation
 60 
 61 class ScopeDesc : public ResourceObj {
 62  public:
 63   // Constructor
 64   ScopeDesc(const nmethod* code, PcDesc* pd, bool ignore_objects = false);
 65 
 66   // Direct access to scope
 67   ScopeDesc* at_offset(int decode_offset) { return new ScopeDesc(this, decode_offset); }
 68 
 69   // JVM state
 70   Method* method()      const { return _method; }
 71   int          bci()      const { return _bci;    }
 72   bool should_reexecute() const { return _reexecute; }
 73   bool rethrow_exception() const { return _rethrow_exception; }
 74   bool return_oop()       const { return _return_oop; }
 75   bool return_scalarized() const { return _return_scalarized; }
 76   // Returns true if one or more NoEscape or ArgEscape objects exist in
 77   // any of the scopes at compiled pc.
 78   bool has_ea_local_in_scope() const { return _has_ea_local_in_scope; }
 79   bool arg_escape()       const { return _arg_escape; }
 80 
 81   GrowableArray<ScopeValue*>*   locals();
 82   GrowableArray<ScopeValue*>*   expressions();
 83   GrowableArray<MonitorValue*>* monitors();
 84   GrowableArray<ScopeValue*>*   objects();
 85 
 86   // Stack walking, returns nullptr if this is the outer most scope.
 87   ScopeDesc* sender() const;
 88 
 89   // Returns where the scope was decoded
 90   int decode_offset() const { return _decode_offset; }
 91 
 92   int sender_decode_offset() const { return _sender_decode_offset; }
 93 
 94   // Tells whether sender() returns nullptr
 95   bool is_top() const;
 96 
 97  private:
 98   void initialize(const ScopeDesc* parent, int decode_offset);
 99   // Alternative constructors
100   ScopeDesc(const ScopeDesc* parent);
101   ScopeDesc(const ScopeDesc* parent, int decode_offset);
102 
103   // JVM state
104   Method*       _method;
105   int           _bci;
106   bool          _reexecute;
107   bool          _rethrow_exception;
108   bool          _return_oop;
109   bool          _return_scalarized;
110   bool          _has_ea_local_in_scope;       // One or more NoEscape or ArgEscape objects exist in
111                                               // any of the scopes at compiled pc.
112   bool          _arg_escape;                  // Compiled Java call in youngest scope passes ArgEscape
113   // Decoding offsets
114   int _decode_offset;
115   int _sender_decode_offset;
116   int _locals_decode_offset;
117   int _expressions_decode_offset;
118   int _monitors_decode_offset;
119 
120   // Object pool
121   GrowableArray<ScopeValue*>* _objects;
122 
123   // Nmethod information
124   const nmethod* _code;
125 
126   // Decoding operations
127   void decode_body();
128   GrowableArray<ScopeValue*>* decode_scope_values(int decode_offset);
129   GrowableArray<MonitorValue*>* decode_monitor_values(int decode_offset);
130   GrowableArray<ScopeValue*>* decode_object_values(int decode_offset);
131 
132   DebugInfoReadStream* stream_at(int decode_offset) const;
133 
134 
135  public:
136   // Verification
137   void verify();
138   GrowableArray<ScopeValue*>* objects_to_rematerialize(frame& frm, RegisterMap& map);
139 
140 #ifndef PRODUCT
141  public:
142   // Printing support
143   void print_on(outputStream* st) const;
144   void print_on(outputStream* st, PcDesc* pd) const;
145   void print_value_on(outputStream* st) const;
146 #endif
147 };
148 
149 #endif // SHARE_CODE_SCOPEDESC_HPP