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Diffstat (limited to 'libgcc/unwind-dw2-fde.h')
-rw-r--r-- | libgcc/unwind-dw2-fde.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/libgcc/unwind-dw2-fde.h b/libgcc/unwind-dw2-fde.h new file mode 100644 index 0000000..6d7a8de --- /dev/null +++ b/libgcc/unwind-dw2-fde.h @@ -0,0 +1,183 @@ +/* Subroutines needed for unwinding stack frames for exception handling. */ +/* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2009 + Free Software Foundation, Inc. + Contributed by Jason Merrill <jason@cygnus.com>. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +#ifndef GCC_UNWIND_DW2_FDE_H +#define GCC_UNWIND_DW2_FDE_H + +#ifndef HIDE_EXPORTS +#pragma GCC visibility push(default) +#endif + +struct fde_vector +{ + const void *orig_data; + size_t count; + const struct dwarf_fde *array[]; +}; + +struct object +{ + void *pc_begin; + void *tbase; + void *dbase; + union { + const struct dwarf_fde *single; + struct dwarf_fde **array; + struct fde_vector *sort; + } u; + + union { + struct { + unsigned long sorted : 1; + unsigned long from_array : 1; + unsigned long mixed_encoding : 1; + unsigned long encoding : 8; + /* ??? Wish there was an easy way to detect a 64-bit host here; + we've got 32 bits left to play with... */ + unsigned long count : 21; + } b; + size_t i; + } s; + +#ifdef DWARF2_OBJECT_END_PTR_EXTENSION + char *fde_end; +#endif + + struct object *next; +}; + +/* This is the original definition of struct object. While the struct + itself was opaque to users, they did know how large it was, and + allocate one statically in crtbegin for each DSO. Keep this around + so that we're aware of the static size limitations for the new struct. */ +struct old_object +{ + void *pc_begin; + void *pc_end; + struct dwarf_fde *fde_begin; + struct dwarf_fde **fde_array; + size_t count; + struct old_object *next; +}; + +struct dwarf_eh_bases +{ + void *tbase; + void *dbase; + void *func; +}; + + +extern void __register_frame_info_bases (const void *, struct object *, + void *, void *); +extern void __register_frame_info (const void *, struct object *); +extern void __register_frame (void *); +extern void __register_frame_info_table_bases (void *, struct object *, + void *, void *); +extern void __register_frame_info_table (void *, struct object *); +extern void __register_frame_table (void *); +extern void *__deregister_frame_info (const void *); +extern void *__deregister_frame_info_bases (const void *); +extern void __deregister_frame (void *); + + +typedef int sword __attribute__ ((mode (SI))); +typedef unsigned int uword __attribute__ ((mode (SI))); +typedef unsigned int uaddr __attribute__ ((mode (pointer))); +typedef int saddr __attribute__ ((mode (pointer))); +typedef unsigned char ubyte; + +/* Terminology: + CIE - Common Information Element + FDE - Frame Descriptor Element + + There is one per function, and it describes where the function code + is located, and what the register lifetimes and stack layout are + within the function. + + The data structures are defined in the DWARF specification, although + not in a very readable way (see LITERATURE). + + Every time an exception is thrown, the code needs to locate the FDE + for the current function, and starts to look for exception regions + from that FDE. This works in a two-level search: + a) in a linear search, find the shared image (i.e. DLL) containing + the PC + b) using the FDE table for that shared object, locate the FDE using + binary search (which requires the sorting). */ + +/* The first few fields of a CIE. The CIE_id field is 0 for a CIE, + to distinguish it from a valid FDE. FDEs are aligned to an addressing + unit boundary, but the fields within are unaligned. */ +struct dwarf_cie +{ + uword length; + sword CIE_id; + ubyte version; + unsigned char augmentation[]; +} __attribute__ ((packed, aligned (__alignof__ (void *)))); + +/* The first few fields of an FDE. */ +struct dwarf_fde +{ + uword length; + sword CIE_delta; + unsigned char pc_begin[]; +} __attribute__ ((packed, aligned (__alignof__ (void *)))); + +typedef struct dwarf_fde fde; + +/* Locate the CIE for a given FDE. */ + +static inline const struct dwarf_cie * +get_cie (const struct dwarf_fde *f) +{ + return (const void *)&f->CIE_delta - f->CIE_delta; +} + +static inline const fde * +next_fde (const fde *f) +{ + return (const fde *) ((const char *) f + f->length + sizeof (f->length)); +} + +extern const fde * _Unwind_Find_FDE (void *, struct dwarf_eh_bases *); + +static inline int +last_fde (struct object *obj __attribute__ ((__unused__)), const fde *f) +{ +#ifdef DWARF2_OBJECT_END_PTR_EXTENSION + return (char *)f == obj->fde_end || f->length == 0; +#else + return f->length == 0; +#endif +} + +#ifndef HIDE_EXPORTS +#pragma GCC visibility pop +#endif + +#endif /* unwind-dw2-fde.h */ |