LCOV - code coverage report
Current view: top level - gcc - domwalk.h (source / functions) Hit Total Coverage
Test: gcc.info Lines: 2 2 100.0 %
Date: 2020-04-04 11:58:09 Functions: 2 2 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 0 0 -

           Branch data     Line data    Source code
       1                 :            : /* Generic dominator tree walker
       2                 :            :    Copyright (C) 2003-2020 Free Software Foundation, Inc.
       3                 :            :    Contributed by Diego Novillo <dnovillo@redhat.com>
       4                 :            : 
       5                 :            : This file is part of GCC.
       6                 :            : 
       7                 :            : GCC is free software; you can redistribute it and/or modify
       8                 :            : it under the terms of the GNU General Public License as published by
       9                 :            : the Free Software Foundation; either version 3, or (at your option)
      10                 :            : any later version.
      11                 :            : 
      12                 :            : GCC is distributed in the hope that it will be useful,
      13                 :            : but WITHOUT ANY WARRANTY; without even the implied warranty of
      14                 :            : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      15                 :            : GNU General Public License for more details.
      16                 :            : 
      17                 :            : You should have received a copy of the GNU General Public License
      18                 :            : along with GCC; see the file COPYING3.  If not see
      19                 :            : <http://www.gnu.org/licenses/>.  */
      20                 :            : 
      21                 :            : #ifndef GCC_DOM_WALK_H
      22                 :            : #define GCC_DOM_WALK_H
      23                 :            : 
      24                 :            : /**
      25                 :            :  * This is the main class for the dominator walker. It is expected that
      26                 :            :  * consumers will have a custom class inheriting from it, which will over ride
      27                 :            :  * at least one of before_dom_children and after_dom_children to implement the
      28                 :            :  * custom behavior.
      29                 :            :  */
      30                 :            : class dom_walker
      31                 :            : {
      32                 :            : public:
      33                 :            :   static const edge STOP;
      34                 :            : 
      35                 :            :   /* An enum for determining whether the dom walk should be constrained to
      36                 :            :      blocks reachable by executable edges.  */
      37                 :            : 
      38                 :            :   enum reachability
      39                 :            :   {
      40                 :            :     /* Walk all blocks within the CFG.  */
      41                 :            :     ALL_BLOCKS,
      42                 :            : 
      43                 :            :     /* Use REACHABLE_BLOCKS when your subclass can discover that some edges
      44                 :            :        are not executable.
      45                 :            : 
      46                 :            :        If a subclass can discover that a COND, SWITCH or GOTO has a static
      47                 :            :        target in the before_dom_children callback, the taken edge should
      48                 :            :        be returned.  The generic walker will clear EDGE_EXECUTABLE on all
      49                 :            :        edges it can determine are not executable.
      50                 :            : 
      51                 :            :        With REACHABLE_BLOCKS, EDGE_EXECUTABLE will be set on every edge in
      52                 :            :        the dom_walker ctor; the flag will then be cleared on edges that are
      53                 :            :        determined to be not executable.  */
      54                 :            :     REACHABLE_BLOCKS,
      55                 :            : 
      56                 :            :     /* Identical to REACHABLE_BLOCKS, but the initial state of EDGE_EXECUTABLE
      57                 :            :        will instead be preserved in the ctor, allowing for information about
      58                 :            :        non-executable edges to be merged in from an earlier analysis (and
      59                 :            :        potentially for additional edges to be marked as non-executable).  */
      60                 :            :     REACHABLE_BLOCKS_PRESERVING_FLAGS
      61                 :            :   };
      62                 :            : 
      63                 :            :   /* You can provide a mapping of basic-block index to RPO if you
      64                 :            :      have that readily available or you do multiple walks.  If you
      65                 :            :      specify NULL as BB_INDEX_TO_RPO dominator children will not be
      66                 :            :      walked in RPO order.  */
      67                 :            :   dom_walker (cdi_direction direction, enum reachability = ALL_BLOCKS,
      68                 :            :               int *bb_index_to_rpo = NULL);
      69                 :            : 
      70                 :            :   ~dom_walker ();
      71                 :            : 
      72                 :            :   /* Walk the dominator tree.  */
      73                 :            :   void walk (basic_block);
      74                 :            : 
      75                 :            :   /* Function to call before the recursive walk of the dominator children.
      76                 :            : 
      77                 :            :      Return value is the always taken edge if the block has multiple outgoing
      78                 :            :      edges, NULL otherwise.  When skipping unreachable blocks, the walker
      79                 :            :      uses the taken edge information to clear EDGE_EXECUTABLE on the other
      80                 :            :      edges, exposing unreachable blocks.  A NULL return value means all
      81                 :            :      outgoing edges should still be considered executable.  A return value
      82                 :            :      of STOP means to stop the domwalk from processing dominated blocks from
      83                 :            :      here.  This can be used to process a SEME region only (note domwalk
      84                 :            :      will still do work linear in function size).  */
      85                 :    7044650 :   virtual edge before_dom_children (basic_block) { return NULL; }
      86                 :            : 
      87                 :            :   /* Function to call after the recursive walk of the dominator children.  */
      88                 :   76309500 :   virtual void after_dom_children (basic_block) {}
      89                 :            : 
      90                 :            : private:
      91                 :            :   /* This is the direction of the dominator tree we want to walk.  i.e.,
      92                 :            :      if it is set to CDI_DOMINATORS, then we walk the dominator tree,
      93                 :            :      if it is set to CDI_POST_DOMINATORS, then we walk the post
      94                 :            :      dominator tree.  */
      95                 :            :   const ENUM_BITFIELD (cdi_direction) m_dom_direction : 2;
      96                 :            :   const ENUM_BITFIELD (reachability) m_reachability : 2;
      97                 :            :   bool m_user_bb_to_rpo;
      98                 :            :   basic_block m_unreachable_dom;
      99                 :            :   int *m_bb_to_rpo;
     100                 :            : 
     101                 :            :   /* Query whether or not the given block is reachable or not.  */
     102                 :            :   bool bb_reachable (struct function *, basic_block);
     103                 :            : 
     104                 :            :   /* Given an unreachable block, propagate that property to outgoing
     105                 :            :      and possibly incoming edges for the block.  Typically called after
     106                 :            :      determining a block is unreachable in the before_dom_children
     107                 :            :      callback.  */
     108                 :            :   void propagate_unreachable_to_edges (basic_block, FILE *, dump_flags_t);
     109                 :            : 
     110                 :            : };
     111                 :            : 
     112                 :            : extern void set_all_edges_as_executable (function *fn);
     113                 :            : 
     114                 :            : #endif

Generated by: LCOV version 1.0

LCOV profile is generated on x86_64 machine using following configure options: configure --disable-bootstrap --enable-coverage=opt --enable-languages=c,c++,fortran,go,jit,lto --enable-host-shared. GCC test suite is run with the built compiler.