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_VC6 0x19930520
  25 #define CXX_FRAME_MAGIC_VC7 0x19930521
  26 #define CXX_FRAME_MAGIC_VC8 0x19930522
  27 #define CXX_EXCEPTION       0xe06d7363
  28
  29 typedef void (*vtable_ptr)(void);
  30
  31 /* type_info object, see cpp.c for implementation */
  32 typedef struct __type_info
  33 {
  34   const vtable_ptr *vtable;
  35   char              *name;        /* Unmangled name, allocated lazily */
  36   char               mangled[32]; /* Variable length, but we declare it large enough for static RTTI */
  37 } type_info;
  38
  39 /* exception object */
  40 typedef struct __exception
  41 {
  42   const vtable_ptr *vtable;
  43   char             *name;    /* Name of this exception, always a new copy for each object */
  44   int               do_free; /* Whether to free 'name' in our dtor */
  45 } exception;
  46
  47 /* the exception frame used by CxxFrameHandler */
  48 typedef struct __cxx_exception_frame
  49 {
  50     EXCEPTION_REGISTRATION_RECORD  frame;    /* the standard exception frame */
  51     int                            trylevel;
  52     DWORD                          ebp;
  53 } cxx_exception_frame;
  54
  55 /* info about a single catch {} block */
  56 typedef struct __catchblock_info
  57 {
  58     UINT             flags;         /* flags (see below) */
  59     const type_info *type_info;     /* C++ type caught by this block */
  60     int              offset;        /* stack offset to copy exception object to */
  61     void           (*handler)(void);/* catch block handler code */
  62 } catchblock_info;
  63 #define TYPE_FLAG_CONST      1
  64 #define TYPE_FLAG_VOLATILE   2
  65 #define TYPE_FLAG_REFERENCE  8
  66
  67 /* info about a single try {} block */
  68 typedef struct __tryblock_info
  69 {
  70     int                    start_level;      /* start trylevel of that block */
  71     int                    end_level;        /* end trylevel of that block */
  72     int                    catch_level;      /* initial trylevel of the catch block */
  73     int                    catchblock_count; /* count of catch blocks in array */
  74     const catchblock_info *catchblock;       /* array of catch blocks */
  75 } tryblock_info;
  76
  77 /* info about the unwind handler for a given trylevel */
  78 typedef struct __unwind_info
  79 {
  80     int    prev;          /* prev trylevel unwind handler, to run after this one */
  81     void (*handler)(void);/* unwind handler */
  82 } unwind_info;
  83
  84 /* descriptor of all try blocks of a given function */
  85 typedef struct __cxx_function_descr
  86 {
  87     UINT                 magic;          /* must be CXX_FRAME_MAGIC */
  88     UINT                 unwind_count;   /* number of unwind handlers */
  89     const unwind_info   *unwind_table;   /* array of unwind handlers */
  90     UINT                 tryblock_count; /* number of try blocks */
  91     const tryblock_info *tryblock;       /* array of try blocks */
  92     UINT                 ipmap_count;
  93     const void          *ipmap;
  94     const void          *expect_list;    /* expected exceptions list when magic >= VC7 */
  95     UINT                 flags;          /* flags when magic >= VC8 */
  96 } cxx_function_descr;
  97
  98 #define FUNC_DESCR_SYNCHRONOUS  1        /* synchronous exceptions only (built with /EHs) */
  99
 100 typedef void (*cxx_copy_ctor)(void);
 101
 102 /* offsets for computing the this pointer */
 103 typedef struct
 104 {
 105     int         this_offset;   /* offset of base class this pointer from start of object */
 106     int         vbase_descr;   /* offset of virtual base class descriptor */
 107     int         vbase_offset;  /* offset of this pointer offset in virtual base class descriptor */
 108 } this_ptr_offsets;
 109
 110 /* complete information about a C++ type */
 111 typedef struct __cxx_type_info
 112 {
 113     UINT             flags;        /* flags (see CLASS_* flags below) */
 114     const type_info *type_info;    /* C++ type info */
 115     this_ptr_offsets offsets;      /* offsets for computing the this pointer */
 116     unsigned int     size;         /* object size */
 117     cxx_copy_ctor    copy_ctor;    /* copy constructor */
 118 } cxx_type_info;
 119 #define CLASS_IS_SIMPLE_TYPE          1
 120 #define CLASS_HAS_VIRTUAL_BASE_CLASS  4
 121
 122 /* table of C++ types that apply for a given object */
 123 typedef struct __cxx_type_info_table
 124 {
 125     UINT                 count;     /* number of types */
 126     const cxx_type_info *info[3];   /* variable length, we declare it large enough for static RTTI */
 127 } cxx_type_info_table;
 128
 129 typedef DWORD (*cxx_exc_custom_handler)( PEXCEPTION_RECORD, cxx_exception_frame*,
 130                                          PCONTEXT, EXCEPTION_REGISTRATION_RECORD**,
 131                                          const cxx_function_descr*, int nested_trylevel,
 132                                          EXCEPTION_REGISTRATION_RECORD *nested_frame, DWORD unknown3 );
 133
 134 /* type information for an exception object */
 135 typedef struct __cxx_exception_type
 136 {
 137     UINT                       flags;            /* TYPE_FLAG flags */
 138     void                     (*destructor)(void);/* exception object destructor */
 139     cxx_exc_custom_handler     custom_handler;   /* custom handler for this exception */
 140     const cxx_type_info_table *type_info_table;  /* list of types for this exception object */
 141 } cxx_exception_type;
 142
 143 void WINAPI _CxxThrowException(exception*,const cxx_exception_type*);
 144 int CDECL _XcptFilter(NTSTATUS, PEXCEPTION_POINTERS);
 145 int CDECL __CppXcptFilter(NTSTATUS, PEXCEPTION_POINTERS);
 146
 147 static inline const char *dbgstr_type_info( const type_info *info )
 148 {
 149     if (!info) return "{}";
 150     return wine_dbg_sprintf( "{vtable=%p name=%s (%s)}",
 151                              info->vtable, info->mangled, info->name ? info->name : "" );
 152 }
 153
 154 /* compute the this pointer for a base class of a given type */
 155 static inline void *get_this_pointer( const this_ptr_offsets *off, void *object )
 156 {
 157     void *this_ptr;
 158     int *offset_ptr;
 159
 160     if (!object) return NULL;
 161     this_ptr = (char *)object + off->this_offset;
 162     if (off->vbase_descr >= 0)
 163     {
 164         /* move this ptr to vbase descriptor */
 165         this_ptr = (char *)this_ptr + off->vbase_descr;
 166         /* and fetch additional offset from vbase descriptor */
 167         offset_ptr = (int *)(*(char **)this_ptr + off->vbase_offset);
 168         this_ptr = (char *)this_ptr + *offset_ptr;
 169     }
 170     return this_ptr;
 171 }
 172
 173 #endif /* __MSVCRT_CPPEXCEPT_H */