1043 lines
23 KiB
C
1043 lines
23 KiB
C
/* dw2gencfi.c - Support for generating Dwarf2 CFI information.
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Copyright 2003 Free Software Foundation, Inc.
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Contributed by Michal Ludvig <mludvig@suse.cz>
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This file is part of GAS, the GNU Assembler.
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GAS is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GAS is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GAS; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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#include "as.h"
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#include "dw2gencfi.h"
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/* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field
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of the CIE. Default to 1 if not otherwise specified. */
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#ifndef DWARF2_LINE_MIN_INSN_LENGTH
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# define DWARF2_LINE_MIN_INSN_LENGTH 1
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#endif
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/* If TARGET_USE_CFIPOP is defined, it is required that the target
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provide the following definitions. Otherwise provide them to
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allow compilation to continue. */
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#ifndef TARGET_USE_CFIPOP
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# ifndef DWARF2_DEFAULT_RETURN_COLUMN
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# define DWARF2_DEFAULT_RETURN_COLUMN 0
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# endif
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# ifndef DWARF2_CIE_DATA_ALIGNMENT
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# define DWARF2_CIE_DATA_ALIGNMENT 1
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# endif
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#endif
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#ifndef EH_FRAME_ALIGNMENT
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# ifdef BFD_ASSEMBLER
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# define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2)
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# else
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# define EH_FRAME_ALIGNMENT 2
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# endif
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#endif
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#ifndef tc_cfi_frame_initial_instructions
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# define tc_cfi_frame_initial_instructions() ((void)0)
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#endif
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struct cfi_insn_data
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{
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struct cfi_insn_data *next;
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int insn;
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union {
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struct {
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unsigned reg;
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offsetT offset;
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} ri;
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struct {
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unsigned reg1;
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unsigned reg2;
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} rr;
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unsigned r;
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offsetT i;
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struct {
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symbolS *lab1;
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symbolS *lab2;
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} ll;
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struct cfi_escape_data {
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struct cfi_escape_data *next;
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expressionS exp;
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} *esc;
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} u;
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};
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struct fde_entry
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{
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struct fde_entry *next;
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symbolS *start_address;
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symbolS *end_address;
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struct cfi_insn_data *data;
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struct cfi_insn_data **last;
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unsigned int return_column;
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};
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struct cie_entry
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{
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struct cie_entry *next;
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symbolS *start_address;
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unsigned int return_column;
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struct cfi_insn_data *first, *last;
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};
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/* Current open FDE entry. */
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static struct fde_entry *cur_fde_data;
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static symbolS *last_address;
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static offsetT cur_cfa_offset;
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/* List of FDE entries. */
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static struct fde_entry *all_fde_data;
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static struct fde_entry **last_fde_data = &all_fde_data;
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/* List of CIEs so that they could be reused. */
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static struct cie_entry *cie_root;
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/* Stack of old CFI data, for save/restore. */
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struct cfa_save_data
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{
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struct cfa_save_data *next;
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offsetT cfa_offset;
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};
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static struct cfa_save_data *cfa_save_stack;
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/* Construct a new FDE structure and add it to the end of the fde list. */
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static struct fde_entry *
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alloc_fde_entry (void)
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{
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struct fde_entry *fde = xcalloc (1, sizeof (struct fde_entry));
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cur_fde_data = fde;
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*last_fde_data = fde;
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last_fde_data = &fde->next;
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fde->last = &fde->data;
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fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN;
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return fde;
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}
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/* The following functions are available for a backend to construct its
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own unwind information, usually from legacy unwind directives. */
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/* Construct a new INSN structure and add it to the end of the insn list
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for the currently active FDE. */
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static struct cfi_insn_data *
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alloc_cfi_insn_data (void)
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{
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struct cfi_insn_data *insn = xcalloc (1, sizeof (struct cfi_insn_data));
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*cur_fde_data->last = insn;
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cur_fde_data->last = &insn->next;
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return insn;
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}
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/* Construct a new FDE structure that begins at LABEL. */
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void
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cfi_new_fde (symbolS *label)
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{
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struct fde_entry *fde = alloc_fde_entry ();
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fde->start_address = label;
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last_address = label;
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}
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/* End the currently open FDE. */
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void
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cfi_end_fde (symbolS *label)
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{
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cur_fde_data->end_address = label;
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cur_fde_data = NULL;
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}
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/* Set the return column for the current FDE. */
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void
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cfi_set_return_column (unsigned regno)
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{
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cur_fde_data->return_column = regno;
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}
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/* Universal functions to store new instructions. */
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static void
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cfi_add_CFA_insn(int insn)
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{
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struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
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insn_ptr->insn = insn;
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}
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static void
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cfi_add_CFA_insn_reg (int insn, unsigned regno)
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{
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struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
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insn_ptr->insn = insn;
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insn_ptr->u.r = regno;
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}
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static void
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cfi_add_CFA_insn_offset (int insn, offsetT offset)
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{
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struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
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insn_ptr->insn = insn;
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insn_ptr->u.i = offset;
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}
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static void
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cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2)
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{
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struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
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insn_ptr->insn = insn;
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insn_ptr->u.rr.reg1 = reg1;
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insn_ptr->u.rr.reg2 = reg2;
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}
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static void
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cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset)
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{
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struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data ();
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insn_ptr->insn = insn;
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insn_ptr->u.ri.reg = regno;
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insn_ptr->u.ri.offset = offset;
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}
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/* Add a CFI insn to advance the PC from the last address to LABEL. */
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void
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cfi_add_advance_loc (symbolS *label)
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{
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struct cfi_insn_data *insn = alloc_cfi_insn_data ();
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insn->insn = DW_CFA_advance_loc;
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insn->u.ll.lab1 = last_address;
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insn->u.ll.lab2 = label;
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last_address = label;
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}
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/* Add a DW_CFA_offset record to the CFI data. */
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void
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cfi_add_CFA_offset (unsigned regno, offsetT offset)
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{
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unsigned int abs_data_align;
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cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset);
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abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0
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? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT);
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if (offset % abs_data_align)
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as_bad (_("register save offset not a multiple of %u"), abs_data_align);
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}
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/* Add a DW_CFA_def_cfa record to the CFI data. */
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void
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cfi_add_CFA_def_cfa (unsigned regno, offsetT offset)
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{
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cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset);
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cur_cfa_offset = offset;
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}
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/* Add a DW_CFA_register record to the CFI data. */
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void
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cfi_add_CFA_register (unsigned reg1, unsigned reg2)
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{
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cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2);
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}
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/* Add a DW_CFA_def_cfa_register record to the CFI data. */
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void
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cfi_add_CFA_def_cfa_register (unsigned regno)
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{
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cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno);
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}
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/* Add a DW_CFA_def_cfa_offset record to the CFI data. */
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void
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cfi_add_CFA_def_cfa_offset (offsetT offset)
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{
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cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset);
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cur_cfa_offset = offset;
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}
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void
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cfi_add_CFA_restore (unsigned regno)
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{
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cfi_add_CFA_insn_reg (DW_CFA_restore, regno);
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}
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void
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cfi_add_CFA_undefined (unsigned regno)
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{
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cfi_add_CFA_insn_reg (DW_CFA_undefined, regno);
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}
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void
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cfi_add_CFA_same_value (unsigned regno)
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{
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cfi_add_CFA_insn_reg (DW_CFA_same_value, regno);
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}
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void
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cfi_add_CFA_remember_state (void)
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{
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struct cfa_save_data *p;
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cfi_add_CFA_insn (DW_CFA_remember_state);
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p = xmalloc (sizeof (*p));
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p->cfa_offset = cur_cfa_offset;
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p->next = cfa_save_stack;
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cfa_save_stack = p;
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}
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void
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cfi_add_CFA_restore_state (void)
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{
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struct cfa_save_data *p;
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cfi_add_CFA_insn (DW_CFA_restore_state);
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p = cfa_save_stack;
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if (p)
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{
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cur_cfa_offset = p->cfa_offset;
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cfa_save_stack = p->next;
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free (p);
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}
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}
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/* Parse CFI assembler directives. */
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static void dot_cfi (int);
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static void dot_cfi_escape (int);
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static void dot_cfi_startproc (int);
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static void dot_cfi_endproc (int);
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/* Fake CFI type; outside the byte range of any real CFI insn. */
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#define CFI_adjust_cfa_offset 0x100
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#define CFI_return_column 0x101
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#define CFI_rel_offset 0x102
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#define CFI_escape 0x103
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const pseudo_typeS cfi_pseudo_table[] =
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{
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{ "cfi_startproc", dot_cfi_startproc, 0 },
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{ "cfi_endproc", dot_cfi_endproc, 0 },
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{ "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa },
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{ "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register },
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{ "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset },
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{ "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset },
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{ "cfi_offset", dot_cfi, DW_CFA_offset },
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{ "cfi_rel_offset", dot_cfi, CFI_rel_offset },
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{ "cfi_register", dot_cfi, DW_CFA_register },
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{ "cfi_return_column", dot_cfi, CFI_return_column },
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{ "cfi_restore", dot_cfi, DW_CFA_restore },
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{ "cfi_undefined", dot_cfi, DW_CFA_undefined },
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{ "cfi_same_value", dot_cfi, DW_CFA_same_value },
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{ "cfi_remember_state", dot_cfi, DW_CFA_remember_state },
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{ "cfi_restore_state", dot_cfi, DW_CFA_restore_state },
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{ "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save },
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{ "cfi_escape", dot_cfi_escape, 0 },
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{ NULL, NULL, 0 }
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};
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static void
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cfi_parse_separator (void)
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{
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SKIP_WHITESPACE ();
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if (*input_line_pointer == ',')
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input_line_pointer++;
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else
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as_bad (_("missing separator"));
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}
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static unsigned
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cfi_parse_reg (void)
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{
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int regno;
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expressionS exp;
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||
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#ifdef tc_regname_to_dw2regnum
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SKIP_WHITESPACE ();
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if (is_name_beginner (*input_line_pointer)
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|| (*input_line_pointer == '%'
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&& is_name_beginner (*++input_line_pointer)))
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{
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char *name, c;
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name = input_line_pointer;
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c = get_symbol_end ();
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if ((regno = tc_regname_to_dw2regnum (name)) < 0)
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{
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as_bad (_("bad register expression"));
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regno = 0;
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}
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||
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*input_line_pointer = c;
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||
return regno;
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}
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||
#endif
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||
|
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expression (&exp);
|
||
switch (exp.X_op)
|
||
{
|
||
case O_register:
|
||
case O_constant:
|
||
regno = exp.X_add_number;
|
||
break;
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||
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||
default:
|
||
as_bad (_("bad register expression"));
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||
regno = 0;
|
||
break;
|
||
}
|
||
|
||
return regno;
|
||
}
|
||
|
||
static offsetT
|
||
cfi_parse_const (void)
|
||
{
|
||
return get_absolute_expression ();
|
||
}
|
||
|
||
static void
|
||
dot_cfi (int arg)
|
||
{
|
||
offsetT offset;
|
||
unsigned reg1, reg2;
|
||
|
||
if (!cur_fde_data)
|
||
{
|
||
as_bad (_("CFI instruction used without previous .cfi_startproc"));
|
||
return;
|
||
}
|
||
|
||
/* If the last address was not at the current PC, advance to current. */
|
||
if (symbol_get_frag (last_address) != frag_now
|
||
|| S_GET_VALUE (last_address) != frag_now_fix ())
|
||
cfi_add_advance_loc (symbol_temp_new_now ());
|
||
|
||
switch (arg)
|
||
{
|
||
case DW_CFA_offset:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_parse_separator ();
|
||
offset = cfi_parse_const ();
|
||
cfi_add_CFA_offset (reg1, offset);
|
||
break;
|
||
|
||
case CFI_rel_offset:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_parse_separator ();
|
||
offset = cfi_parse_const ();
|
||
cfi_add_CFA_offset (reg1, offset - cur_cfa_offset);
|
||
break;
|
||
|
||
case DW_CFA_def_cfa:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_parse_separator ();
|
||
offset = cfi_parse_const ();
|
||
cfi_add_CFA_def_cfa (reg1, offset);
|
||
break;
|
||
|
||
case DW_CFA_register:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_parse_separator ();
|
||
reg2 = cfi_parse_reg ();
|
||
cfi_add_CFA_register (reg1, reg2);
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_register:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_add_CFA_def_cfa_register (reg1);
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_offset:
|
||
offset = cfi_parse_const ();
|
||
cfi_add_CFA_def_cfa_offset (offset);
|
||
break;
|
||
|
||
case CFI_adjust_cfa_offset:
|
||
offset = cfi_parse_const ();
|
||
cfi_add_CFA_def_cfa_offset (cur_cfa_offset + offset);
|
||
break;
|
||
|
||
case DW_CFA_restore:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_add_CFA_restore (reg1);
|
||
break;
|
||
|
||
case DW_CFA_undefined:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_add_CFA_undefined (reg1);
|
||
break;
|
||
|
||
case DW_CFA_same_value:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_add_CFA_same_value (reg1);
|
||
break;
|
||
|
||
case CFI_return_column:
|
||
reg1 = cfi_parse_reg ();
|
||
cfi_set_return_column (reg1);
|
||
break;
|
||
|
||
case DW_CFA_remember_state:
|
||
cfi_add_CFA_remember_state ();
|
||
break;
|
||
|
||
case DW_CFA_restore_state:
|
||
cfi_add_CFA_restore_state ();
|
||
break;
|
||
|
||
case DW_CFA_GNU_window_save:
|
||
cfi_add_CFA_insn (DW_CFA_GNU_window_save);
|
||
break;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
|
||
demand_empty_rest_of_line ();
|
||
}
|
||
|
||
static void
|
||
dot_cfi_escape (int ignored ATTRIBUTE_UNUSED)
|
||
{
|
||
struct cfi_escape_data *head, **tail, *e;
|
||
struct cfi_insn_data *insn;
|
||
|
||
if (!cur_fde_data)
|
||
{
|
||
as_bad (_("CFI instruction used without previous .cfi_startproc"));
|
||
return;
|
||
}
|
||
|
||
/* If the last address was not at the current PC, advance to current. */
|
||
if (symbol_get_frag (last_address) != frag_now
|
||
|| S_GET_VALUE (last_address) != frag_now_fix ())
|
||
cfi_add_advance_loc (symbol_temp_new_now ());
|
||
|
||
tail = &head;
|
||
do
|
||
{
|
||
e = xmalloc (sizeof (*e));
|
||
do_parse_cons_expression (&e->exp, 1);
|
||
*tail = e;
|
||
tail = &e->next;
|
||
}
|
||
while (*input_line_pointer++ == ',');
|
||
*tail = NULL;
|
||
|
||
insn = alloc_cfi_insn_data ();
|
||
insn->insn = CFI_escape;
|
||
insn->u.esc = head;
|
||
}
|
||
|
||
static void
|
||
dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED)
|
||
{
|
||
int simple = 0;
|
||
|
||
if (cur_fde_data)
|
||
{
|
||
as_bad (_("previous CFI entry not closed (missing .cfi_endproc)"));
|
||
return;
|
||
}
|
||
|
||
cfi_new_fde (symbol_temp_new_now ());
|
||
|
||
SKIP_WHITESPACE ();
|
||
if (is_name_beginner (*input_line_pointer))
|
||
{
|
||
char *name, c;
|
||
|
||
name = input_line_pointer;
|
||
c = get_symbol_end ();
|
||
|
||
if (strcmp (name, "simple") == 0)
|
||
{
|
||
simple = 1;
|
||
*input_line_pointer = c;
|
||
}
|
||
else
|
||
input_line_pointer = name;
|
||
}
|
||
demand_empty_rest_of_line ();
|
||
|
||
if (!simple)
|
||
tc_cfi_frame_initial_instructions ();
|
||
}
|
||
|
||
static void
|
||
dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED)
|
||
{
|
||
if (! cur_fde_data)
|
||
{
|
||
as_bad (_(".cfi_endproc without corresponding .cfi_startproc"));
|
||
return;
|
||
}
|
||
|
||
cfi_end_fde (symbol_temp_new_now ());
|
||
}
|
||
|
||
|
||
/* Emit a single byte into the current segment. */
|
||
|
||
static inline void
|
||
out_one (int byte)
|
||
{
|
||
FRAG_APPEND_1_CHAR (byte);
|
||
}
|
||
|
||
/* Emit a two-byte word into the current segment. */
|
||
|
||
static inline void
|
||
out_two (int data)
|
||
{
|
||
md_number_to_chars (frag_more (2), data, 2);
|
||
}
|
||
|
||
/* Emit a four byte word into the current segment. */
|
||
|
||
static inline void
|
||
out_four (int data)
|
||
{
|
||
md_number_to_chars (frag_more (4), data, 4);
|
||
}
|
||
|
||
/* Emit an unsigned "little-endian base 128" number. */
|
||
|
||
static void
|
||
out_uleb128 (addressT value)
|
||
{
|
||
output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0);
|
||
}
|
||
|
||
/* Emit an unsigned "little-endian base 128" number. */
|
||
|
||
static void
|
||
out_sleb128 (offsetT value)
|
||
{
|
||
output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1);
|
||
}
|
||
|
||
static void
|
||
output_cfi_insn (struct cfi_insn_data *insn)
|
||
{
|
||
offsetT offset;
|
||
unsigned int regno;
|
||
|
||
switch (insn->insn)
|
||
{
|
||
case DW_CFA_advance_loc:
|
||
{
|
||
symbolS *from = insn->u.ll.lab1;
|
||
symbolS *to = insn->u.ll.lab2;
|
||
|
||
if (symbol_get_frag (to) == symbol_get_frag (from))
|
||
{
|
||
addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from);
|
||
addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH;
|
||
|
||
if (scaled <= 0x3F)
|
||
out_one (DW_CFA_advance_loc + scaled);
|
||
else if (delta <= 0xFF)
|
||
{
|
||
out_one (DW_CFA_advance_loc1);
|
||
out_one (delta);
|
||
}
|
||
else if (delta <= 0xFFFF)
|
||
{
|
||
out_one (DW_CFA_advance_loc2);
|
||
out_two (delta);
|
||
}
|
||
else
|
||
{
|
||
out_one (DW_CFA_advance_loc4);
|
||
out_four (delta);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
expressionS exp;
|
||
|
||
exp.X_op = O_subtract;
|
||
exp.X_add_symbol = to;
|
||
exp.X_op_symbol = from;
|
||
exp.X_add_number = 0;
|
||
|
||
/* The code in ehopt.c expects that one byte of the encoding
|
||
is already allocated to the frag. This comes from the way
|
||
that it scans the .eh_frame section looking first for the
|
||
.byte DW_CFA_advance_loc4. */
|
||
frag_more (1);
|
||
|
||
frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3,
|
||
make_expr_symbol (&exp), frag_now_fix () - 1,
|
||
(char *) frag_now);
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_def_cfa:
|
||
offset = insn->u.ri.offset;
|
||
if (offset < 0)
|
||
{
|
||
out_one (DW_CFA_def_cfa_sf);
|
||
out_uleb128 (insn->u.ri.reg);
|
||
out_uleb128 (offset);
|
||
}
|
||
else
|
||
{
|
||
out_one (DW_CFA_def_cfa);
|
||
out_uleb128 (insn->u.ri.reg);
|
||
out_uleb128 (offset);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_register:
|
||
case DW_CFA_undefined:
|
||
case DW_CFA_same_value:
|
||
out_one (insn->insn);
|
||
out_uleb128 (insn->u.r);
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_offset:
|
||
offset = insn->u.i;
|
||
if (offset < 0)
|
||
{
|
||
out_one (DW_CFA_def_cfa_offset_sf);
|
||
out_sleb128 (offset);
|
||
}
|
||
else
|
||
{
|
||
out_one (DW_CFA_def_cfa_offset);
|
||
out_uleb128 (offset);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_restore:
|
||
regno = insn->u.r;
|
||
if (regno <= 0x3F)
|
||
{
|
||
out_one (DW_CFA_restore + regno);
|
||
}
|
||
else
|
||
{
|
||
out_one (DW_CFA_restore_extended);
|
||
out_uleb128 (regno);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_offset:
|
||
regno = insn->u.ri.reg;
|
||
offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT;
|
||
if (offset < 0)
|
||
{
|
||
out_one (DW_CFA_offset_extended_sf);
|
||
out_uleb128 (regno);
|
||
out_sleb128 (offset);
|
||
}
|
||
else if (regno <= 0x3F)
|
||
{
|
||
out_one (DW_CFA_offset + regno);
|
||
out_uleb128 (offset);
|
||
}
|
||
else
|
||
{
|
||
out_one (DW_CFA_offset_extended);
|
||
out_uleb128 (regno);
|
||
out_uleb128 (offset);
|
||
}
|
||
break;
|
||
|
||
case DW_CFA_register:
|
||
out_one (DW_CFA_register);
|
||
out_uleb128 (insn->u.rr.reg1);
|
||
out_uleb128 (insn->u.rr.reg2);
|
||
break;
|
||
|
||
case DW_CFA_remember_state:
|
||
case DW_CFA_restore_state:
|
||
out_one (insn->insn);
|
||
break;
|
||
|
||
case DW_CFA_GNU_window_save:
|
||
out_one (DW_CFA_GNU_window_save);
|
||
break;
|
||
|
||
case CFI_escape:
|
||
{
|
||
struct cfi_escape_data *e;
|
||
for (e = insn->u.esc; e ; e = e->next)
|
||
emit_expr (&e->exp, 1);
|
||
break;
|
||
}
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
static void
|
||
output_cie (struct cie_entry *cie)
|
||
{
|
||
symbolS *after_size_address, *end_address;
|
||
expressionS exp;
|
||
struct cfi_insn_data *i;
|
||
|
||
cie->start_address = symbol_temp_new_now ();
|
||
after_size_address = symbol_temp_make ();
|
||
end_address = symbol_temp_make ();
|
||
|
||
exp.X_op = O_subtract;
|
||
exp.X_add_symbol = end_address;
|
||
exp.X_op_symbol = after_size_address;
|
||
exp.X_add_number = 0;
|
||
|
||
emit_expr (&exp, 4); /* Length */
|
||
symbol_set_value_now (after_size_address);
|
||
out_four (0); /* CIE id */
|
||
out_one (DW_CIE_VERSION); /* Version */
|
||
out_one ('z'); /* Augmentation */
|
||
out_one ('R');
|
||
out_one (0);
|
||
out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment */
|
||
out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment */
|
||
out_one (cie->return_column); /* Return column */
|
||
out_uleb128 (1); /* Augmentation size */
|
||
#if defined DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr
|
||
out_one (DW_EH_PE_pcrel | DW_EH_PE_sdata4);
|
||
#else
|
||
out_one (DW_EH_PE_sdata4);
|
||
#endif
|
||
|
||
if (cie->first)
|
||
for (i = cie->first; i != cie->last; i = i->next)
|
||
output_cfi_insn (i);
|
||
|
||
frag_align (2, 0, 0);
|
||
symbol_set_value_now (end_address);
|
||
}
|
||
|
||
static void
|
||
output_fde (struct fde_entry *fde, struct cie_entry *cie,
|
||
struct cfi_insn_data *first, int align)
|
||
{
|
||
symbolS *after_size_address, *end_address;
|
||
expressionS exp;
|
||
|
||
after_size_address = symbol_temp_make ();
|
||
end_address = symbol_temp_make ();
|
||
|
||
exp.X_op = O_subtract;
|
||
exp.X_add_symbol = end_address;
|
||
exp.X_op_symbol = after_size_address;
|
||
exp.X_add_number = 0;
|
||
emit_expr (&exp, 4); /* Length */
|
||
symbol_set_value_now (after_size_address);
|
||
|
||
exp.X_add_symbol = after_size_address;
|
||
exp.X_op_symbol = cie->start_address;
|
||
emit_expr (&exp, 4); /* CIE offset */
|
||
|
||
#ifdef DIFF_EXPR_OK
|
||
exp.X_add_symbol = fde->start_address;
|
||
exp.X_op_symbol = symbol_temp_new_now ();
|
||
emit_expr (&exp, 4); /* Code offset */
|
||
#else
|
||
exp.X_op = O_symbol;
|
||
exp.X_add_symbol = fde->start_address;
|
||
exp.X_op_symbol = NULL;
|
||
#ifdef tc_cfi_emit_pcrel_expr
|
||
tc_cfi_emit_pcrel_expr (&exp, 4); /* Code offset */
|
||
#else
|
||
emit_expr (&exp, 4); /* Code offset */
|
||
#endif
|
||
exp.X_op = O_subtract;
|
||
#endif
|
||
|
||
exp.X_add_symbol = fde->end_address;
|
||
exp.X_op_symbol = fde->start_address; /* Code length */
|
||
emit_expr (&exp, 4);
|
||
|
||
out_uleb128 (0); /* Augmentation size */
|
||
|
||
for (; first; first = first->next)
|
||
output_cfi_insn (first);
|
||
|
||
frag_align (align, 0, 0);
|
||
symbol_set_value_now (end_address);
|
||
}
|
||
|
||
static struct cie_entry *
|
||
select_cie_for_fde (struct fde_entry *fde, struct cfi_insn_data **pfirst)
|
||
{
|
||
struct cfi_insn_data *i, *j;
|
||
struct cie_entry *cie;
|
||
|
||
for (cie = cie_root; cie; cie = cie->next)
|
||
{
|
||
if (cie->return_column != fde->return_column)
|
||
continue;
|
||
for (i = cie->first, j = fde->data;
|
||
i != cie->last && j != NULL;
|
||
i = i->next, j = j->next)
|
||
{
|
||
if (i->insn != j->insn)
|
||
goto fail;
|
||
switch (i->insn)
|
||
{
|
||
case DW_CFA_advance_loc:
|
||
/* We reached the first advance in the FDE, but did not
|
||
reach the end of the CIE list. */
|
||
goto fail;
|
||
|
||
case DW_CFA_offset:
|
||
case DW_CFA_def_cfa:
|
||
if (i->u.ri.reg != j->u.ri.reg)
|
||
goto fail;
|
||
if (i->u.ri.offset != j->u.ri.offset)
|
||
goto fail;
|
||
break;
|
||
|
||
case DW_CFA_register:
|
||
if (i->u.rr.reg1 != j->u.rr.reg1)
|
||
goto fail;
|
||
if (i->u.rr.reg2 != j->u.rr.reg2)
|
||
goto fail;
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_register:
|
||
case DW_CFA_restore:
|
||
case DW_CFA_undefined:
|
||
case DW_CFA_same_value:
|
||
if (i->u.r != j->u.r)
|
||
goto fail;
|
||
break;
|
||
|
||
case DW_CFA_def_cfa_offset:
|
||
if (i->u.i != j->u.i)
|
||
goto fail;
|
||
break;
|
||
|
||
case CFI_escape:
|
||
/* Don't bother matching these for now. */
|
||
goto fail;
|
||
|
||
default:
|
||
abort ();
|
||
}
|
||
}
|
||
|
||
/* Success if we reached the end of the CIE list, and we've either
|
||
run out of FDE entries or we've encountered an advance. */
|
||
if (i == cie->last && (!j || j->insn == DW_CFA_advance_loc))
|
||
{
|
||
*pfirst = j;
|
||
return cie;
|
||
}
|
||
|
||
fail:;
|
||
}
|
||
|
||
cie = xmalloc (sizeof (struct cie_entry));
|
||
cie->next = cie_root;
|
||
cie_root = cie;
|
||
cie->return_column = fde->return_column;
|
||
cie->first = fde->data;
|
||
|
||
for (i = cie->first; i ; i = i->next)
|
||
if (i->insn == DW_CFA_advance_loc)
|
||
break;
|
||
|
||
cie->last = i;
|
||
*pfirst = i;
|
||
|
||
output_cie (cie);
|
||
|
||
return cie;
|
||
}
|
||
|
||
void
|
||
cfi_finish (void)
|
||
{
|
||
segT cfi_seg;
|
||
struct fde_entry *fde;
|
||
int save_flag_traditional_format;
|
||
|
||
if (cur_fde_data)
|
||
{
|
||
as_bad (_("open CFI at the end of file; missing .cfi_endproc directive"));
|
||
cur_fde_data->end_address = cur_fde_data->start_address;
|
||
}
|
||
|
||
if (all_fde_data == 0)
|
||
return;
|
||
|
||
/* Open .eh_frame section. */
|
||
cfi_seg = subseg_new (".eh_frame", 0);
|
||
#ifdef BFD_ASSEMBLER
|
||
bfd_set_section_flags (stdoutput, cfi_seg,
|
||
SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_READONLY);
|
||
#endif
|
||
subseg_set (cfi_seg, 0);
|
||
record_alignment (cfi_seg, EH_FRAME_ALIGNMENT);
|
||
|
||
/* Make sure check_eh_frame doesn't do anything with our output. */
|
||
save_flag_traditional_format = flag_traditional_format;
|
||
flag_traditional_format = 1;
|
||
|
||
for (fde = all_fde_data; fde ; fde = fde->next)
|
||
{
|
||
struct cfi_insn_data *first;
|
||
struct cie_entry *cie;
|
||
|
||
cie = select_cie_for_fde (fde, &first);
|
||
output_fde (fde, cie, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2);
|
||
}
|
||
|
||
flag_traditional_format = save_flag_traditional_format;
|
||
}
|