bcEscapeAnalyzer.hpp revision 1568
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* published by the Free Software Foundation.
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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// This class implements a fast, conservative analysis of effect of methods
// on the escape state of their arguments. The analysis is at the bytecode
// level.
class ciMethodBlocks;
class ciBlock;
class BCEscapeAnalyzer : public ResourceObj {
private:
bool _conservative; // If true, return maximally
// conservative results.
int _arg_size;
enum{ ARG_OFFSET_MAX = 31};
bool _return_local;
bool _return_allocated;
bool _allocated_escapes;
bool _unknown_modified;
int _level;
public:
class ArgumentMap;
class StateInfo;
private:
// helper functions
bool is_argument(int i) { return i >= 0 && i < _arg_size; }
void iterate_blocks(Arena *);
// analysis
void initialize();
void clear_escape_info();
void compute_escape_info();
bool do_analysis();
void read_escape_info();
public:
// accessors
// retrieval of interprocedural escape information
// The given argument does not escape the callee.
bool is_arg_local(int i) const {
}
// The given argument escapes the callee, but does not become globally
// reachable.
bool is_arg_stack(int i) const {
}
// The given argument does not escape globally, and may be returned.
bool is_arg_returned(int i) const {
// True iff only input arguments are returned.
bool is_return_local() const {
return !_conservative && _return_local;
}
// True iff only newly allocated unescaped objects are returned.
bool is_return_allocated() const {
}
// Tracking of argument modification
enum {OFFSET_ANY = -1};
bool has_non_arg_side_affects() { return _unknown_modified; }
// Copy dependencies from this analysis into "deps"
#ifndef PRODUCT
// dump escape information
void dump();
#endif
};