dlls/msvcrt/cppexcept.h

   1 /*
   2  * msvcrt C++ exception handling
   3  *
   4  * Copyright 2002 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #ifndef __MSVCRT_CPPEXCEPT_H
  22 #define __MSVCRT_CPPEXCEPT_H
  23
  24 #define CXX_FRAME_MAGIC    0x19930520
  25 #define CXX_EXCEPTION      0xe06d7363
  26
  27 typedef void (*vtable_ptr)();
  28
  29 /* type_info object, see cpp.c for inplementation */
  30 typedef struct __type_info
  31 {
  32   const vtable_ptr *vtable;
  33   char              *name;        /* Unmangled name, allocated lazily */
  34   char               mangled[32]; /* Variable length, but we declare it large enough for static RTTI */
  35 } type_info;
  36
  37 /* exception object */
  38 typedef struct __exception
  39 {
  40   const vtable_ptr *vtable;
  41   char             *name;    /* Name of this exception, always a new copy for each object */
  42   int               do_free; /* Whether to free 'name' in our dtor */
  43 } exception;
  44
  45 /* the exception frame used by CxxFrameHandler */
  46 typedef struct __cxx_exception_frame
  47 {
  48     EXCEPTION_REGISTRATION_RECORD  frame;    /* the standard exception frame */
  49     int                            trylevel;
  50     DWORD                          ebp;
  51 } cxx_exception_frame;
  52
  53 /* info about a single catch {} block */
  54 typedef struct __catchblock_info
  55 {
  56     UINT       flags;         /* flags (see below) */
  57     type_info *type_info;     /* C++ type caught by this block */
  58     int        offset;        /* stack offset to copy exception object to */
  59     void     (*handler)();    /* catch block handler code */
  60 } catchblock_info;
  61 #define TYPE_FLAG_CONST      1
  62 #define TYPE_FLAG_VOLATILE   2
  63 #define TYPE_FLAG_REFERENCE  8
  64
  65 /* info about a single try {} block */
  66 typedef struct __tryblock_info
  67 {
  68     int              start_level;      /* start trylevel of that block */
  69     int              end_level;        /* end trylevel of that block */
  70     int              catch_level;      /* initial trylevel of the catch block */
  71     int              catchblock_count; /* count of catch blocks in array */
  72     catchblock_info *catchblock;       /* array of catch blocks */
  73 } tryblock_info;
  74
  75 /* info about the unwind handler for a given trylevel */
  76 typedef struct __unwind_info
  77 {
  78     int    prev;          /* prev trylevel unwind handler, to run after this one */
  79     void (*handler)();    /* unwind handler */
  80 } unwind_info;
  81
  82 /* descriptor of all try blocks of a given function */
  83 typedef struct __cxx_function_descr
  84 {
  85     UINT           magic;          /* must be CXX_FRAME_MAGIC */
  86     UINT           unwind_count;   /* number of unwind handlers */
  87     unwind_info   *unwind_table;   /* array of unwind handlers */
  88     UINT           tryblock_count; /* number of try blocks */
  89     tryblock_info *tryblock;       /* array of try blocks */
  90     UINT           unknown[3];
  91 } cxx_function_descr;
  92
  93 typedef void (*cxx_copy_ctor)(void);
  94
  95 /* offsets for computing the this pointer */
  96 typedef struct
  97 {
  98     int         this_offset;   /* offset of base class this pointer from start of object */
  99     int         vbase_descr;   /* offset of virtual base class descriptor */
 100     int         vbase_offset;  /* offset of this pointer offset in virtual base class descriptor */
 101 } this_ptr_offsets;
 102
 103 /* complete information about a C++ type */
 104 typedef struct __cxx_type_info
 105 {
 106     UINT             flags;        /* flags (see CLASS_* flags below) */
 107     const type_info *type_info;    /* C++ type info */
 108     this_ptr_offsets offsets;      /* offsets for computing the this pointer */
 109     size_t           size;         /* object size */
 110     cxx_copy_ctor    copy_ctor;    /* copy constructor */
 111 } cxx_type_info;
 112 #define CLASS_IS_SIMPLE_TYPE          1
 113 #define CLASS_HAS_VIRTUAL_BASE_CLASS  4
 114
 115 /* table of C++ types that apply for a given object */
 116 typedef struct __cxx_type_info_table
 117 {
 118     UINT                 count;     /* number of types */
 119     const cxx_type_info *info[3];   /* variable length, we declare it large enough for static RTTI */
 120 } cxx_type_info_table;
 121
 122 typedef DWORD (*cxx_exc_custom_handler)( PEXCEPTION_RECORD, cxx_exception_frame*,
 123                                          PCONTEXT, EXCEPTION_REGISTRATION_RECORD**,
 124                                          cxx_function_descr*, int nested_trylevel,
 125                                          EXCEPTION_REGISTRATION_RECORD *nested_frame, DWORD unknown3 );
 126
 127 /* type information for an exception object */
 128 typedef struct __cxx_exception_type
 129 {
 130     UINT                       flags;            /* TYPE_FLAG flags */
 131     void                     (*destructor)();    /* exception object destructor */
 132     cxx_exc_custom_handler     custom_handler;   /* custom handler for this exception */
 133     const cxx_type_info_table *type_info_table;  /* list of types for this exception object */
 134 } cxx_exception_type;
 135
 136 void _CxxThrowException(exception*,const cxx_exception_type*);
 137
 138 /* get the vtable pointer for a C++ object */
 139 static inline const vtable_ptr *get_vtable( void *obj )
 140 {
 141     return *(const vtable_ptr **)obj;
 142 }
 143
 144 static inline const char *dbgstr_type_info( const type_info *info )
 145 {
 146     if (!info) return "{}";
 147     return wine_dbg_sprintf( "{vtable=%p name=%s (%s)}",
 148                              info->vtable, info->mangled, info->name ? info->name : "" );
 149 }
 150
 151 /* compute the this pointer for a base class of a given type */
 152 static inline void *get_this_pointer( const this_ptr_offsets *off, void *object )
 153 {
 154     void *this_ptr;
 155     int *offset_ptr;
 156
 157     if (!object) return NULL;
 158     this_ptr = (char *)object + off->this_offset;
 159     if (off->vbase_descr >= 0)
 160     {
 161         /* move this ptr to vbase descriptor */
 162         this_ptr = (char *)this_ptr + off->vbase_descr;
 163         /* and fetch additional offset from vbase descriptor */
 164         offset_ptr = (int *)(*(char **)this_ptr + off->vbase_offset);
 165         this_ptr = (char *)this_ptr + *offset_ptr;
 166     }
 167     return this_ptr;
 168 }
 169
 170 #endif /* __MSVCRT_CPPEXCEPT_H */