libgcc/config/darwin10-unwind-find-enc-func.c

   1 #include "libgcc_tm.h"
   2
   3 /* This shim is special, it needs to be built for Mac OSX 10.6
   4    regardless of the current system version.
   5    We must also build it to use the unwinder layout that was
   6    present for 10.6 (and not update that).
   7    So we copy the referenced structures from unwind-dw2-fde.h
   8    to avoid pulling in newer system headers and/or changed
   9    layouts.  */
  10 struct dwarf_eh_bases
  11 {
  12   void *tbase;
  13   void *dbase;
  14   void *func;
  15 };
  16
  17 typedef          int  sword __attribute__ ((mode (SI)));
  18 typedef unsigned int  uword __attribute__ ((mode (SI)));
  19
  20 /* The first few fields of an FDE.  */
  21 struct dwarf_fde
  22 {
  23   uword length;
  24   sword CIE_delta;
  25   unsigned char pc_begin[];
  26 } __attribute__ ((packed, aligned (__alignof__ (void *))));
  27
  28 typedef struct dwarf_fde fde;
  29
  30 extern const fde * _Unwind_Find_FDE (void *, struct dwarf_eh_bases *);
  31
  32 void *
  33 _darwin10_Unwind_FindEnclosingFunction (void *pc)
  34 {
  35   struct dwarf_eh_bases bases;
  36   const struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases);
  37   if (fde)
  38     return bases.func;
  39   return (void *) 0;
  40 }