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_COMPLEX_LONG_DOUBLE + 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 class builtins_manager; // declared within jit-builtins.h
 101 class tempdir;
 102
 103 namespace recording {
 104
 105   /* Recording types.  */
 106
 107   /* Indentation indicates inheritance: */
 108   class context;
 109   class memento;
 110     class string;
 111     class location;
 112     class type;
 113       class function_type;
 114       class compound_type;
 115         class struct_;
 116         class union_;
 117     class field;
 118     class fields;
 119     class function;
 120     class block;
 121     class rvalue;
 122       class lvalue;
 123         class local;
 124         class global;
 125         class param;
 126     class statement;
 127
 128   /* End of recording types. */
 129 }
 130
 131 namespace playback {
 132   /* Playback types.  */
 133
 134   /* Indentation indicates inheritance: */
 135   class context;
 136   class wrapper;
 137     class type;
 138       class compound_type;
 139     class field;
 140     class function;
 141     class block;
 142     class rvalue;
 143       class lvalue;
 144         class param;
 145     class source_file;
 146     class source_line;
 147     class location;
 148
 149   /* End of playback types. */
 150 }
 151
 152 typedef playback::context replayer;
 153
 154 class dump
 155 {
 156 public:
 157   dump (recording::context &ctxt,
 158         const char *filename,
 159         bool update_locations);
 160   ~dump ();
 161
 162   void write (const char *fmt, ...)
 163     GNU_PRINTF(2, 3);
 164
 165   bool update_locations () const { return m_update_locations; }
 166
 167   recording::location *
 168   make_location () const;
 169
 170 private:
 171   recording::context &m_ctxt;
 172   const char *m_filename;
 173   bool m_update_locations;
 174   int m_line;
 175   int m_column;
 176   FILE *m_file;
 177 };
 178
 179 } // namespace gcc::jit
 180
 181 } // namespace gcc
 182
 183 #endif /* JIT_COMMON_H */