gcc/jit/jit-common.h

   1 /* Core of implementation of libgccjit.so
   2    Copyright (C) 2013-2014 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 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, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 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 JIT_COMMON_H
  22 #define JIT_COMMON_H
  23
  24 #include "libgccjit.h"
  25
  26 #include "tree.h"
  27 #include "tree-iterator.h"
  28
  29 #ifdef GCC_VERSION
  30 #if GCC_VERSION >= 4001
  31 #define GNU_PRINTF(M, N) __attribute__ ((format (gnu_printf, (M), (N))))
  32 #else
  33 #define GNU_PRINTF(M, N)
  34 #endif
  35 #endif
  36
  37 const int NUM_GCC_JIT_TYPES = GCC_JIT_TYPE_FILE_PTR + 1;
  38
  39 /* This comment is included by the docs.
  40
  41    In order to allow jit objects to be usable outside of a compile
  42    whilst working with the existing structure of GCC's code the
  43    C API is implemented in terms of a gcc::jit::recording::context,
  44    which records the calls made to it.
  45
  46    When a gcc_jit_context is compiled, the recording context creates a
  47    playback context.  The playback context invokes the bulk of the GCC
  48    code, and within the "frontend" parsing hook, plays back the recorded
  49    API calls, creating GCC tree objects.
  50
  51    So there are two parallel families of classes: those relating to
  52    recording, and those relating to playback:
  53
  54    * Visibility: recording objects are exposed back to client code,
  55      whereas playback objects are internal to the library.
  56
  57    * Lifetime: recording objects have a lifetime equal to that of the
  58      recording context that created them, whereas playback objects only
  59      exist within the frontend hook.
  60
  61    * Memory allocation: recording objects are allocated by the recording
  62      context, and automatically freed by it when the context is released,
  63      whereas playback objects are allocated within the GC heap, and
  64      garbage-collected; they can own GC-references.
  65
  66    * Integration with rest of GCC: recording objects are unrelated to the
  67      rest of GCC, whereas playback objects are wrappers around "tree"
  68      instances.  Hence you can't ask a recording rvalue or lvalue what its
  69      type is, whereas you can for a playback rvalue of lvalue (since it
  70      can work with the underlying GCC tree nodes).
  71
  72    * Instancing: There can be multiple recording contexts "alive" at once
  73      (albeit it only one compiling at once), whereas there can only be one
  74      playback context alive at one time (since it interacts with the GC).
  75
  76    Ultimately if GCC could support multiple GC heaps and contexts, and
  77    finer-grained initialization, then this recording vs playback
  78    distinction could be eliminated.
  79
  80    During a playback, we associate objects from the recording with
  81    their counterparts during this playback.  For simplicity, we store this
  82    within the recording objects, as ``void *m_playback_obj``, casting it to
  83    the appropriate playback object subclass.  For these casts to make
  84    sense, the two class hierarchies need to have the same structure.
  85
  86    Note that the playback objects that ``m_playback_obj`` points to are
  87    GC-allocated, but the recording objects don't own references:
  88    these associations only exist within a part of the code where
  89    the GC doesn't collect, and are set back to NULL before the GC can
  90    run.
  91
  92    End of comment for inclusion in the docs.  */
  93
  94 namespace gcc {
  95
  96 namespace jit {
  97
  98 class result;
  99 class dump;
 100
 101 namespace recording {
 102
 103   /* Recording types.  */
 104
 105   /* Indentation indicates inheritance: */
 106   class context;
 107   class builtins_manager; // declared within jit-builtins.h
 108   class memento;
 109     class string;
 110     class location;
 111     class type;
 112       class function_type;
 113       class compound_type;
 114         class struct_;
 115         class union_;
 116     class field;
 117     class fields;
 118     class function;
 119     class block;
 120     class rvalue;
 121       class lvalue;
 122         class local;
 123         class global;
 124         class param;
 125     class statement;
 126
 127   /* End of recording types. */
 128 }
 129
 130 namespace playback {
 131   /* Playback types.  */
 132
 133   /* Indentation indicates inheritance: */
 134   class context;
 135   class wrapper;
 136     class type;
 137       class compound_type;
 138     class field;
 139     class function;
 140     class block;
 141     class rvalue;
 142       class lvalue;
 143         class param;
 144     class source_file;
 145     class source_line;
 146     class location;
 147
 148   /* End of playback types. */
 149 }
 150
 151 typedef playback::context replayer;
 152
 153 class dump
 154 {
 155 public:
 156   dump (recording::context &ctxt,
 157         const char *filename,
 158         bool update_locations);
 159   ~dump ();
 160
 161   void write (const char *fmt, ...)
 162     GNU_PRINTF(2, 3);
 163
 164   bool update_locations () const { return m_update_locations; }
 165
 166   recording::location *
 167   make_location () const;
 168
 169 private:
 170   recording::context &m_ctxt;
 171   const char *m_filename;
 172   bool m_update_locations;
 173   int m_line;
 174   int m_column;
 175   FILE *m_file;
 176 };
 177
 178 } // namespace gcc::jit
 179
 180 } // namespace gcc
 181
 182 #endif /* JIT_COMMON_H */