gcc/jit/jit-common.h

   1 /* Core of implementation of libgccjit.so
   2    Copyright (C) 2013-2020 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 "vec.h"
  27 #include "tree.h"
  28 #include "inchash.h"
  29 #include "tree-iterator.h"
  30
  31 #ifdef GCC_VERSION
  32 #if GCC_VERSION >= 4001
  33 #define GNU_PRINTF(M, N) __attribute__ ((format (gnu_printf, (M), (N))))
  34 #else
  35 #define GNU_PRINTF(M, N)
  36 #endif
  37 #endif
  38
  39 const int NUM_GCC_JIT_TYPES = GCC_JIT_TYPE_COMPLEX_LONG_DOUBLE + 1;
  40
  41 /* This comment is included by the docs.
  42
  43    In order to allow jit objects to be usable outside of a compile
  44    whilst working with the existing structure of GCC's code the
  45    C API is implemented in terms of a gcc::jit::recording::context,
  46    which records the calls made to it.
  47
  48    When a gcc_jit_context is compiled, the recording context creates a
  49    playback context.  The playback context invokes the bulk of the GCC
  50    code, and within the "frontend" parsing hook, plays back the recorded
  51    API calls, creating GCC tree objects.
  52
  53    So there are two parallel families of classes: those relating to
  54    recording, and those relating to playback:
  55
  56    * Visibility: recording objects are exposed back to client code,
  57      whereas playback objects are internal to the library.
  58
  59    * Lifetime: recording objects have a lifetime equal to that of the
  60      recording context that created them, whereas playback objects only
  61      exist within the frontend hook.
  62
  63    * Memory allocation: recording objects are allocated by the recording
  64      context, and automatically freed by it when the context is released,
  65      whereas playback objects are allocated within the GC heap, and
  66      garbage-collected; they can own GC-references.
  67
  68    * Integration with rest of GCC: recording objects are unrelated to the
  69      rest of GCC, whereas playback objects are wrappers around "tree"
  70      instances.  Hence you can't ask a recording rvalue or lvalue what its
  71      type is, whereas you can for a playback rvalue of lvalue (since it
  72      can work with the underlying GCC tree nodes).
  73
  74    * Instancing: There can be multiple recording contexts "alive" at once
  75      (albeit it only one compiling at once), whereas there can only be one
  76      playback context alive at one time (since it interacts with the GC).
  77
  78    Ultimately if GCC could support multiple GC heaps and contexts, and
  79    finer-grained initialization, then this recording vs playback
  80    distinction could be eliminated.
  81
  82    During a playback, we associate objects from the recording with
  83    their counterparts during this playback.  For simplicity, we store this
  84    within the recording objects, as ``void *m_playback_obj``, casting it to
  85    the appropriate playback object subclass.  For these casts to make
  86    sense, the two class hierarchies need to have the same structure.
  87
  88    Note that the playback objects that ``m_playback_obj`` points to are
  89    GC-allocated, but the recording objects don't own references:
  90    these associations only exist within a part of the code where
  91    the GC doesn't collect, and are set back to NULL before the GC can
  92    run.
  93
  94    End of comment for inclusion in the docs.  */
  95
  96 namespace gcc {
  97
  98 namespace jit {
  99
 100 class result;
 101 class dump;
 102 class logger;
 103 class builtins_manager; // declared within jit-builtins.h
 104 class tempdir;
 105
 106 namespace recording {
 107
 108   /* Recording types.  */
 109
 110   /* Indentation indicates inheritance: */
 111   class context;
 112   class memento;
 113     class string;
 114     class location;
 115     class type;
 116       class function_type;
 117       class compound_type;
 118         class struct_;
 119         class union_;
 120       class vector_type;
 121     class field;
 122       class bitfield;
 123     class fields;
 124     class function;
 125     class block;
 126     class rvalue;
 127       class lvalue;
 128         class local;
 129         class global;
 130         class param;
 131       class base_call;
 132       class function_pointer;
 133     class statement;
 134     class case_;
 135
 136   /* End of recording types. */
 137 }
 138
 139 namespace playback {
 140   /* Playback types.  */
 141
 142   /* Indentation indicates inheritance: */
 143   class context;
 144   class wrapper;
 145     class type;
 146       class compound_type;
 147     class field;
 148     class function;
 149     class block;
 150     class rvalue;
 151       class lvalue;
 152         class param;
 153     class source_file;
 154     class source_line;
 155     class location;
 156     class case_;
 157
 158   /* End of playback types. */
 159 }
 160
 161 typedef playback::context replayer;
 162
 163 class dump
 164 {
 165 public:
 166   dump (recording::context &ctxt,
 167         const char *filename,
 168         bool update_locations);
 169   ~dump ();
 170
 171   recording::context &get_context () { return m_ctxt; }
 172
 173   void write (const char *fmt, ...)
 174     GNU_PRINTF(2, 3);
 175
 176   bool update_locations () const { return m_update_locations; }
 177
 178   recording::location *
 179   make_location () const;
 180
 181   FILE *get_file () const { return m_file; }
 182
 183 private:
 184   recording::context &m_ctxt;
 185   const char *m_filename;
 186   bool m_update_locations;
 187   int m_line;
 188   int m_column;
 189   FILE *m_file;
 190 };
 191
 192 /* A hidden enum of boolean options that are only exposed via API
 193    entrypoints, rather than via gcc_jit_context_set_bool_option.  */
 194
 195 enum inner_bool_option
 196 {
 197   INNER_BOOL_OPTION_ALLOW_UNREACHABLE_BLOCKS,
 198   INNER_BOOL_OPTION_USE_EXTERNAL_DRIVER,
 199
 200   NUM_INNER_BOOL_OPTIONS
 201 };
 202
 203 } // namespace gcc::jit
 204
 205 } // namespace gcc
 206
 207 #endif /* JIT_COMMON_H */