1  /* Hooks to abstract the runtime meta-data generation for Objective C.
       2     Copyright (C) 2011-2023 Free Software Foundation, Inc.
       3     Contributed by Iain Sandoe
       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 _OBJC_RUNTIME_HOOKS_H_
      22  #define _OBJC_RUNTIME_HOOKS_H_
      23  
      24  /* A set of hooks for the front end to obtain runtime-specific actions.  */
      25  
      26  /* Objective-C supports several runtime library variants:
      27  
      28     "GNU" runtime selected by -fgnu-runtime (currently at ABI version 8).
      29     "NeXT" runtime (selected by -fnext-runtime) and installed on OSX/Darwin
      30     systems at API version 1 (for m32 code) and version 2 (for m64 code).
      31  
      32     The runtimes require different data types/layouts, method call mechanisms
      33     and so on, and the purpose of this interface is to abstract such
      34     differences from the parser's perspective.  */
      35  
      36  /* TODO: Do we want the initial underscore ? */
      37  struct objc_runtime_hooks
      38  {
      39    /* TODO: Expand comments in this file.  */
      40  
      41    /* Initialize for this runtime.  */
      42    void (*initialize) (void);
      43    const char *default_constant_string_class_name;
      44  
      45    /* FIXME: Having to check this name should not be necessary.  */
      46    const char *tag_getclass;
      47    /* id for superclass class field - named differently in the existing
      48       runtimes.  */
      49    tree (*super_superclassfield_ident) (void);
      50  
      51    /* Obtain a class decl for the identifier.  */
      52    tree (*class_decl) (tree);
      53    /* Obtain a metaclass decl for the identifier.  */
      54    tree (*metaclass_decl) (tree);
      55    /* Obtain a category decl for the identifier.  */
      56    tree (*category_decl) (tree);
      57    /* Obtain a protocol decl for the identifier.  */
      58    tree (*protocol_decl) (tree);
      59    /* Obtain a string decl, to be placed in the nominated string-section.  */
      60    tree (*string_decl) (tree, const char *, string_section);
      61  
      62    /* Obtain a class reference, generating the fwd def. if necessary.  */
      63    tree (*get_class_reference) (tree);
      64    /* build/get selector reference.  */
      65    tree (*build_selector_reference) (location_t, tree, tree);
      66    /* Get a protocol reference, generating the forward def. if necessary.  */
      67    tree (*get_protocol_reference) (location_t, tree);
      68    /* Get an ivar ref. re the base.  */
      69    tree (*build_ivar_reference) (location_t, tree, tree);
      70    /* Get a reference to {meta}class' super.  */
      71    tree (*get_class_super_ref) (location_t, struct imp_entry *, bool);
      72    /* Get a reference to Category {meta}class' super.  */
      73    tree (*get_category_super_ref) (location_t, struct imp_entry *, bool);
      74  
      75    /* Receiver is class Object, check runtime-specific.  */
      76    tree (*receiver_is_class_object) (tree);
      77    /* Get the start of a method argument type list (receiver, _cmd).  */
      78    void (*get_arg_type_list_base) (vec<tree, va_gc> **, tree, int, int);
      79    /* Build method call.  */
      80    tree (*build_objc_method_call) (location_t, tree, tree, tree, tree, tree, int);
      81  
      82    /* Check for or otherwise handle a request to check that the constant
      83       string class reference is set-up & OK.  */
      84    bool (*setup_const_string_class_decl) (void);
      85    /* Return the tree reprenting a const string constructor for the arg.
      86       Most of the data are in global trees.  */
      87    tree (*build_const_string_constructor) (location_t, tree, int);
      88  
      89    /* Exceptions.  */
      90    tree (*build_throw_stmt) (location_t, tree, bool);
      91    tree (*build_exc_ptr) (struct objc_try_context **);
      92    tree (*begin_catch) (struct objc_try_context **, tree, tree, tree, bool);
      93    void (*finish_catch) (struct objc_try_context **, tree);
      94    tree (*finish_try_stmt) (struct objc_try_context **);
      95  
      96    /* Emit all the metadata required by the runtime - based on the tables built
      97       during parsing.  */
      98    void (*generate_metadata) (void);
      99  
     100  };
     101  
     102  /* For shared support that needs to access these.  */
     103  extern objc_runtime_hooks runtime;
     104  
     105  /* One per runtime at present.
     106     TODO: Make into some kind of configury-generated table.  */
     107  extern bool objc_gnu_runtime_abi_01_init (objc_runtime_hooks *);
     108  extern bool objc_next_runtime_abi_01_init (objc_runtime_hooks *);
     109  extern bool objc_next_runtime_abi_02_init (objc_runtime_hooks *);
     110  
     111  #endif /* _OBJC_RUNTIME_HOOKS_H_ */