text: /*
     +----------------------------------------------------------------------+
     | Zend Engine, CFG - Control Flow Graph                                |
     +----------------------------------------------------------------------+
     | Copyright (c) 1998-2017 The PHP Group                                |
     +----------------------------------------------------------------------+
     | This source file is subject to version 3.01 of the PHP license,      |
     | that is bundled with this package in the file LICENSE, and is        |
     | available through the world-wide-web at the following url:           |
     | http://www.php.net/license/3_01.txt                                  |
     | If you did not receive a copy of the PHP license and are unable to   |
     | obtain it through the world-wide-web, please send a note to          |
     | license@php.net so we can mail you a copy immediately.               |
     +----------------------------------------------------------------------+
     | Authors: Dmitry Stogov <dmitry@zend.com>                             |
     +----------------------------------------------------------------------+
  */
  
  #ifndef ZEND_CFG_H
  #define ZEND_CFG_H
  
  /* zend_basic_bloc.flags */
  #define ZEND_BB_START            (1<<0)  /* fist block             */
  #define ZEND_BB_FOLLOW           (1<<1)  /* follows the next block */
  #define ZEND_BB_TARGET           (1<<2)  /* jump taget             */
  #define ZEND_BB_EXIT             (1<<3)  /* without successors     */
  #define ZEND_BB_ENTRY            (1<<4)  /* stackless entry        */
  #define ZEND_BB_TRY              (1<<5)  /* start of try block     */
  #define ZEND_BB_CATCH            (1<<6)  /* start of catch block   */
  #define ZEND_BB_FINALLY          (1<<7)  /* start of finally block */
  #define ZEND_BB_FINALLY_END      (1<<8)  /* end of finally block   */
  #define ZEND_BB_GEN_VAR          (1<<9)  /* start of live range    */
  #define ZEND_BB_KILL_VAR         (1<<10) /* end of live range      */
  #define ZEND_BB_UNREACHABLE_FREE (1<<11) /* unreachable loop free  */
  #define ZEND_BB_RECV_ENTRY       (1<<12) /* RECV entry             */
  
  #define ZEND_BB_LOOP_HEADER      (1<<16)
  #define ZEND_BB_IRREDUCIBLE_LOOP (1<<17)
  
  #define ZEND_BB_REACHABLE        (1<<31)
  
  #define ZEND_BB_PROTECTED        (ZEND_BB_ENTRY|ZEND_BB_RECV_ENTRY|ZEND_BB_TRY|ZEND_BB_CATCH|ZEND_BB_FINALLY|ZEND_BB_FINALLY_END|ZEND_BB_GEN_VAR|ZEND_BB_KILL_VAR)
  
  typedef struct _zend_basic_block {
  	int              *successors;         /* successor block indices     */
  	uint32_t          flags;
  	uint32_t          start;              /* first opcode number         */
  	uint32_t          len;                /* number of opcodes           */
  	int               successors_count;   /* number of successors        */
  	int               predecessors_count; /* number of predecessors      */
  	int               predecessor_offset; /* offset of 1-st predecessor  */
  	int               idom;               /* immediate dominator block   */
  	int               loop_header;        /* closest loop header, or -1  */
  	int               level;              /* steps away from the entry in the dom. tree */
  	int               children;           /* list of dominated blocks    */
  	int               next_child;         /* next dominated block        */
  	int               successors_storage[2]; /* up to 2 successor blocks */
  } zend_basic_block;
  
  /*
  +------------+---+---+---+---+---+
  |            |OP1|OP2|EXT| 0 | 1 |
  +------------+---+---+---+---+---+
  |JMP         |ADR|   |   |OP1| - |
  |JMPZ        |   |ADR|   |OP2|FOL|
  |JMPNZ       |   |ADR|   |OP2|FOL|
  |JMPZNZ      |   |ADR|ADR|OP2|EXT|
  |JMPZ_EX     |   |ADR|   |OP2|FOL|
  |JMPNZ_EX    |   |ADR|   |OP2|FOL|
  |JMP_SET     |   |ADR|   |OP2|FOL|
  |COALESCE    |   |ADR|   |OP2|FOL|
  |ASSERT_CHK  |   |ADR|   |OP2|FOL|
  |NEW         |   |ADR|   |OP2|FOL|
  |DCL_ANON*   |ADR|   |   |OP1|FOL|
  |FE_RESET_*  |   |ADR|   |OP2|FOL|
  |FE_FETCH_*  |   |   |ADR|EXT|FOL|
  |CATCH       |   |   |ADR|EXT|FOL|
  |FAST_CALL   |ADR|   |   |OP1|FOL|
  |FAST_RET    |   |   |   | - | - |
  |RETURN*     |   |   |   | - | - |
  |EXIT        |   |   |   | - | - |
  |THROW       |   |   |   | - | - |
  |*           |   |   |   |FOL| - |
  +------------+---+---+---+---+---+
  */
  
  typedef struct _zend_cfg {
  	int               blocks_count;       /* number of basic blocks      */
  	int               edges_count;        /* number of edges             */
  	zend_basic_block *blocks;             /* array of basic blocks       */
  	int              *predecessors;
  	uint32_t         *map;
  	uint32_t          flags;
  } zend_cfg;
  
  /* Build Flags */
  #define ZEND_RT_CONSTANTS              (1<<31)
  #define ZEND_CFG_STACKLESS             (1<<30)
  #define ZEND_SSA_DEBUG_LIVENESS        (1<<29)
  #define ZEND_SSA_DEBUG_PHI_PLACEMENT   (1<<28)
  #define ZEND_SSA_RC_INFERENCE          (1<<27)
  #define ZEND_CFG_SPLIT_AT_LIVE_RANGES  (1<<26)
  #define ZEND_CFG_NO_ENTRY_PREDECESSORS (1<<25)
  #define ZEND_CFG_RECV_ENTRY            (1<<24)
  #define ZEND_CALL_TREE                 (1<<23)
  #define ZEND_SSA_USE_CV_RESULTS        (1<<22)
  
  #define CRT_CONSTANT_EX(op_array, opline, node, rt_constants) \
  	((rt_constants) ? \
  		RT_CONSTANT(opline, (node)) \
  	: \
  		CT_CONSTANT_EX(op_array, (node).constant) \
  	)
  
  #define CRT_CONSTANT(node) \
  	CRT_CONSTANT_EX(op_array, opline, node, (build_flags & ZEND_RT_CONSTANTS))
  
  #define RETURN_VALUE_USED(opline) \
  	((opline)->result_type != IS_UNUSED)
  
  BEGIN_EXTERN_C()
  
  int  zend_build_cfg(zend_arena **arena, const zend_op_array *op_array, uint32_t build_flags, zend_cfg *cfg);
  void zend_cfg_remark_reachable_blocks(const zend_op_array *op_array, zend_cfg *cfg);
  int  zend_cfg_build_predecessors(zend_arena **arena, zend_cfg *cfg);
  int  zend_cfg_compute_dominators_tree(const zend_op_array *op_array, zend_cfg *cfg);
  int  zend_cfg_identify_loops(const zend_op_array *op_array, zend_cfg *cfg);
  
  END_EXTERN_C()
  
  #endif /* ZEND_CFG_H */
  
  /*
   * Local variables:
   * tab-width: 4
   * c-basic-offset: 4
   * indent-tabs-mode: t
   * End:
   */
  