binutils-gdb/gas/dw2gencfi.h
Jan Beulich 696025802e gas: allow labeling of CFI instructions
When runtime patching code (like e.g. done by the Linux kernel) there
may be cases where the set of stack frame alterations differs between
unpatched and patched code. Consequently the corresponding unwind data
needs patching too. Locating the right places within an FDE, however,
is rather cumbersome without a way to insert labels in the resulting
section. Hence this patch introduces a new directive, .cfi_label. Note
that with the way CFI data gets emitted currently (at the end of the
assembly process) this can't support local FB- and dollar-labels.

gas/
2015-01-12  Jan Beulich  <jbeulich@suse.com>

	* gas/dw2gencfi.c (cfi_add_label, dot_cfi_label): New.
	(cfi_pseudo_table): Add "cfi_label".
	(output_cfi_insn): Handle CFI_label.
	(select_cie_for_fde): Als terminate CIE when encountering
	CFI_label.
	* dw2gencfi.h (cfi_add_label): Declare.
	(struct cfi_insn_data): New member "sym_name".
	(CFI_label): New.
	* read.c (read_symbol_name): Drop "static".
	* read.h (read_symbol_name): Declare.

gas/testsuite/
2015-01-12  Jan Beulich  <jbeulich@suse.com>

	gas/cfi/cfi-label.d, gas/cfi/cfi-label.s: New.
	gas/cfi/cfi.exp: Run new tests.
2015-01-12 15:24:20 +01:00

137 lines
3.4 KiB
C

/* dw2gencfi.h - Support for generating Dwarf2 CFI information.
Copyright (C) 2003-2015 Free Software Foundation, Inc.
Contributed by Michal Ludvig <mludvig@suse.cz>
This file is part of GAS, the GNU Assembler.
GAS 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.
GAS 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.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
#ifndef DW2GENCFI_H
#define DW2GENCFI_H
#include "dwarf2.h"
struct symbol;
extern const pseudo_typeS cfi_pseudo_table[];
/* cfi_finish() is called at the end of file. It will complain if
the last CFI wasn't properly closed by .cfi_endproc. */
extern void cfi_finish (void);
/* Entry points for backends to add unwind information. */
extern void cfi_new_fde (struct symbol *);
extern void cfi_end_fde (struct symbol *);
extern void cfi_set_return_column (unsigned);
extern void cfi_add_advance_loc (struct symbol *);
extern void cfi_add_label (const char *);
extern void cfi_add_CFA_offset (unsigned, offsetT);
extern void cfi_add_CFA_def_cfa (unsigned, offsetT);
extern void cfi_add_CFA_register (unsigned, unsigned);
extern void cfi_add_CFA_def_cfa_register (unsigned);
extern void cfi_add_CFA_def_cfa_offset (offsetT);
extern void cfi_add_CFA_restore (unsigned);
extern void cfi_add_CFA_undefined (unsigned);
extern void cfi_add_CFA_same_value (unsigned);
extern void cfi_add_CFA_remember_state (void);
extern void cfi_add_CFA_restore_state (void);
/* Structures for md_cfi_end. */
#if defined (TE_PE) || defined (TE_PEP)
#define SUPPORT_FRAME_LINKONCE 1
#else
#define SUPPORT_FRAME_LINKONCE 0
#endif
struct cfi_insn_data
{
struct cfi_insn_data *next;
#if SUPPORT_FRAME_LINKONCE
segT cur_seg;
#endif
int insn;
union
{
struct
{
unsigned reg;
offsetT offset;
} ri;
struct
{
unsigned reg1;
unsigned reg2;
} rr;
unsigned r;
offsetT i;
struct
{
symbolS *lab1;
symbolS *lab2;
} ll;
struct cfi_escape_data *esc;
struct
{
unsigned reg, encoding;
expressionS exp;
} ea;
const char *sym_name;
} u;
};
struct fde_entry
{
struct fde_entry *next;
#if SUPPORT_FRAME_LINKONCE
segT cur_seg;
#endif
symbolS *start_address;
symbolS *end_address;
struct cfi_insn_data *data;
struct cfi_insn_data **last;
unsigned char per_encoding;
unsigned char lsda_encoding;
expressionS personality;
expressionS lsda;
unsigned int return_column;
unsigned int signal_frame;
#if SUPPORT_FRAME_LINKONCE
int handled;
#endif
};
/* The list of all FDEs that have been collected. */
extern struct fde_entry *all_fde_data;
/* Fake CFI type; outside the byte range of any real CFI insn. */
#define CFI_adjust_cfa_offset 0x100
#define CFI_return_column 0x101
#define CFI_rel_offset 0x102
#define CFI_escape 0x103
#define CFI_signal_frame 0x104
#define CFI_val_encoded_addr 0x105
#define CFI_label 0x106
#endif /* DW2GENCFI_H */