67 // header holding length and catch_pco of the subtable, followed
68 // by 'length' entries for each exception handler that can be reached
69 // from the corresponding CatchNode. The catch_pco is the pc offset of
70 // the CatchNode in the corresponding nmethod. Empty subtables are dis-
71 // carded.
72 //
73 // Structure of the table:
74 //
75 // table = { subtable }.
76 // subtable = header entry { entry }.
77 // header = a pair (number of subtable entries, catch pc offset, [unused])
78 // entry = a pair (handler bci, handler pc offset, scope depth)
79 //
80 // An ExceptionHandlerTable can be created from scratch, in which case
81 // it is possible to add subtables. It can also be created from an
82 // nmethod (for lookup purposes) in which case the table cannot be
83 // modified.
84
85 class nmethod;
86 class ExceptionHandlerTable {
87 private:
88 HandlerTableEntry* _table; // the table
89 int _length; // the current length of the table
90 int _size; // the number of allocated entries
91 ReallocMark _nesting; // assertion check for reallocations
92
93 public:
94 // add the entry & grow the table if needed
95 void add_entry(HandlerTableEntry entry);
96 HandlerTableEntry* subtable_for(int catch_pco) const;
97
98 // (compile-time) construction within compiler
99 ExceptionHandlerTable(int initial_size = 8);
100
101 // (run-time) construction from nmethod
102 ExceptionHandlerTable(const nmethod* nm);
103
104 // (compile-time) add entries
105 void add_subtable(
106 int catch_pco, // the pc offset for the CatchNode
107 GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis
108 GrowableArray<intptr_t>* scope_depths_from_top_scope,
109 // if representing exception handlers in multiple
110 // inlined scopes, indicates which scope relative to
111 // the youngest/innermost one in which we are performing
112 // the lookup; zero (or null GrowableArray) indicates
113 // innermost scope
114 GrowableArray<intptr_t>* handler_pcos // pc offsets for the compiled handlers
115 );
116
117 // nmethod support
118 int size_in_bytes() const { return align_up(_length * (int)sizeof(HandlerTableEntry), oopSize); }
119 void copy_to(nmethod* nm);
120 void copy_bytes_to(address addr);
121
122 // lookup
123 HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const;
124
125 // debugging
126 void print_subtable(HandlerTableEntry* t, address base = nullptr) const;
127 void print(address base = nullptr) const;
128 void print_subtable_for(int catch_pco) const;
129 };
130
131
132 // ----------------------------------------------------------------------------
133 // Implicit null exception tables. Maps an exception PC offset to a
134 // continuation PC offset. During construction it's a variable sized
135 // array with a max size and current length. When stored inside an
136 // nmethod a zero length table takes no space. This is detected by
137 // nul_chk_table_size() == 0. Otherwise the table has a length word
138 // followed by pairs of <excp-offset, const-offset>.
139
140 // Use 32-bit representation for offsets
141 typedef uint implicit_null_entry;
142
143 class ImplicitExceptionTable {
144 uint _size;
145 uint _len;
146 implicit_null_entry *_data;
147 implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; }
148 ReallocMark _nesting; // assertion check for reallocations
149
150 public:
151 ImplicitExceptionTable( ) : _size(0), _len(0), _data(0) { }
152 // (run-time) construction from nmethod
153 ImplicitExceptionTable(const nmethod *nm);
154
155 void set_size( uint size );
156 void append( uint exec_off, uint cont_off );
157
158 #if INCLUDE_JVMCI
159 void add_deoptimize(uint exec_off) {
160 // Use the same offset as a marker value for deoptimization
161 append(exec_off, exec_off);
162 }
163 #endif
164
165 // Returns the offset to continue execution at. If the returned
166 // value equals exec_off then the dispatch is expected to be a
167 // deoptimization instead.
168 uint continuation_offset( uint exec_off ) const;
169
170 uint len() const { return _len; }
171
172 uint get_exec_offset(uint i) { assert(i < _len, "oob"); return *adr(i); }
173 uint get_cont_offset(uint i) { assert(i < _len, "oob"); return *(adr(i) + 1); }
174
175 int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * (int)sizeof(implicit_null_entry)); }
176
177 void copy_to(nmethod* nm);
178 void copy_bytes_to(address addr, int size);
179 void print(address base) const;
180 void verify(nmethod *nm) const;
181 };
182
183 #endif // SHARE_CODE_EXCEPTIONHANDLERTABLE_HPP
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67 // header holding length and catch_pco of the subtable, followed
68 // by 'length' entries for each exception handler that can be reached
69 // from the corresponding CatchNode. The catch_pco is the pc offset of
70 // the CatchNode in the corresponding nmethod. Empty subtables are dis-
71 // carded.
72 //
73 // Structure of the table:
74 //
75 // table = { subtable }.
76 // subtable = header entry { entry }.
77 // header = a pair (number of subtable entries, catch pc offset, [unused])
78 // entry = a pair (handler bci, handler pc offset, scope depth)
79 //
80 // An ExceptionHandlerTable can be created from scratch, in which case
81 // it is possible to add subtables. It can also be created from an
82 // nmethod (for lookup purposes) in which case the table cannot be
83 // modified.
84
85 class nmethod;
86 class ExceptionHandlerTable {
87 friend class SCCache;
88 friend class SCCReader;
89
90 private:
91 HandlerTableEntry* _table; // the table
92 int _length; // the current length of the table
93 int _size; // the number of allocated entries
94 ReallocMark _nesting; // assertion check for reallocations
95
96 int length() const { return _length; }
97 void set_length(int length) { _length = length; }
98 public:
99 // add the entry & grow the table if needed
100 void add_entry(HandlerTableEntry entry);
101 HandlerTableEntry* subtable_for(int catch_pco) const;
102
103 // (compile-time) construction within compiler
104 ExceptionHandlerTable(int initial_size = 8);
105
106 // (run-time) construction from nmethod
107 ExceptionHandlerTable(const nmethod* nm);
108
109 // (compile-time) add entries
110 void add_subtable(
111 int catch_pco, // the pc offset for the CatchNode
112 GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis
113 GrowableArray<intptr_t>* scope_depths_from_top_scope,
114 // if representing exception handlers in multiple
115 // inlined scopes, indicates which scope relative to
116 // the youngest/innermost one in which we are performing
117 // the lookup; zero (or null GrowableArray) indicates
118 // innermost scope
119 GrowableArray<intptr_t>* handler_pcos // pc offsets for the compiled handlers
120 );
121
122 HandlerTableEntry* table() const { return _table; }
123 // nmethod support
124 int size_in_bytes() const { return align_up(_length * (int)sizeof(HandlerTableEntry), oopSize); }
125 void copy_to(nmethod* nm);
126 void copy_bytes_to(address addr);
127
128 // lookup
129 HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const;
130
131 // debugging
132 void print_subtable(HandlerTableEntry* t, address base = nullptr) const;
133 void print(address base = nullptr) const;
134 void print_subtable_for(int catch_pco) const;
135 };
136
137
138 // ----------------------------------------------------------------------------
139 // Implicit null exception tables. Maps an exception PC offset to a
140 // continuation PC offset. During construction it's a variable sized
141 // array with a max size and current length. When stored inside an
142 // nmethod a zero length table takes no space. This is detected by
143 // nul_chk_table_size() == 0. Otherwise the table has a length word
144 // followed by pairs of <excp-offset, const-offset>.
145
146 // Use 32-bit representation for offsets
147 typedef uint implicit_null_entry;
148
149 class ImplicitExceptionTable {
150 friend class SCCache;
151 friend class SCCReader;
152 private:
153 uint _size;
154 uint _len;
155 implicit_null_entry *_data;
156 implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; }
157 ReallocMark _nesting; // assertion check for reallocations
158
159 void set_len(int length) { _len = length; }
160
161 public:
162 ImplicitExceptionTable( ) : _size(0), _len(0), _data(0) { }
163 // (run-time) construction from nmethod
164 ImplicitExceptionTable(const nmethod *nm);
165
166 void set_size( uint size );
167 void append( uint exec_off, uint cont_off );
168
169 #if INCLUDE_JVMCI
170 void add_deoptimize(uint exec_off) {
171 // Use the same offset as a marker value for deoptimization
172 append(exec_off, exec_off);
173 }
174 #endif
175
176 // Returns the offset to continue execution at. If the returned
177 // value equals exec_off then the dispatch is expected to be a
178 // deoptimization instead.
179 uint continuation_offset( uint exec_off ) const;
180
181 uint len() const { return _len; }
182
183 implicit_null_entry* data() const { return _data; }
184
185 uint get_exec_offset(uint i) { assert(i < _len, "oob"); return *adr(i); }
186 uint get_cont_offset(uint i) { assert(i < _len, "oob"); return *(adr(i) + 1); }
187
188 int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * (int)sizeof(implicit_null_entry)); }
189
190 void copy_to(nmethod* nm);
191 void copy_bytes_to(address addr, int size);
192 void print(address base) const;
193 void verify(nmethod *nm) const;
194 };
195
196 #endif // SHARE_CODE_EXCEPTIONHANDLERTABLE_HPP
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