| /* Subroutines needed for unwinding stack frames for exception handling. */ |
| /* Copyright (C) 1997-2021 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 f == (const fde *) 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 */ |