| /* dw2gencfi.c - Support for generating Dwarf2 CFI information. |
| Copyright 2003, 2004, 2005, 2006 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 2, 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. */ |
| |
| #include "as.h" |
| #include "dw2gencfi.h" |
| |
| |
| /* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field |
| of the CIE. Default to 1 if not otherwise specified. */ |
| #ifndef DWARF2_LINE_MIN_INSN_LENGTH |
| # define DWARF2_LINE_MIN_INSN_LENGTH 1 |
| #endif |
| |
| /* If TARGET_USE_CFIPOP is defined, it is required that the target |
| provide the following definitions. Otherwise provide them to |
| allow compilation to continue. */ |
| #ifndef TARGET_USE_CFIPOP |
| # ifndef DWARF2_DEFAULT_RETURN_COLUMN |
| # define DWARF2_DEFAULT_RETURN_COLUMN 0 |
| # endif |
| # ifndef DWARF2_CIE_DATA_ALIGNMENT |
| # define DWARF2_CIE_DATA_ALIGNMENT 1 |
| # endif |
| #endif |
| |
| #ifndef EH_FRAME_ALIGNMENT |
| # define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2) |
| #endif |
| |
| #ifndef tc_cfi_frame_initial_instructions |
| # define tc_cfi_frame_initial_instructions() ((void)0) |
| #endif |
| |
| |
| struct cfi_insn_data |
| { |
| struct cfi_insn_data *next; |
| 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 { |
| struct cfi_escape_data *next; |
| expressionS exp; |
| } *esc; |
| } u; |
| }; |
| |
| struct fde_entry |
| { |
| struct fde_entry *next; |
| symbolS *start_address; |
| symbolS *end_address; |
| struct cfi_insn_data *data; |
| struct cfi_insn_data **last; |
| unsigned int return_column; |
| unsigned int signal_frame; |
| }; |
| |
| struct cie_entry |
| { |
| struct cie_entry *next; |
| symbolS *start_address; |
| unsigned int return_column; |
| unsigned int signal_frame; |
| struct cfi_insn_data *first, *last; |
| }; |
| |
| |
| /* Current open FDE entry. */ |
| static struct fde_entry *cur_fde_data; |
| static symbolS *last_address; |
| static offsetT cur_cfa_offset; |
| |
| /* List of FDE entries. */ |
| static struct fde_entry *all_fde_data; |
| static struct fde_entry **last_fde_data = &all_fde_data; |
| |
| /* List of CIEs so that they could be reused. */ |
| static struct cie_entry *cie_root; |
| |
| /* Stack of old CFI data, for save/restore. */ |
| struct cfa_save_data |
| { |
| struct cfa_save_data *next; |
| offsetT cfa_offset; |
| }; |
| |
| static struct cfa_save_data *cfa_save_stack; |
| |
| /* Construct a new FDE structure and add it to the end of the fde list. */ |
| |
| static struct fde_entry * |
| alloc_fde_entry (void) |
| { |
| struct fde_entry *fde = xcalloc (1, sizeof (struct fde_entry)); |
| |
| cur_fde_data = fde; |
| *last_fde_data = fde; |
| last_fde_data = &fde->next; |
| |
| fde->last = &fde->data; |
| fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN; |
| |
| return fde; |
| } |
| |
| /* The following functions are available for a backend to construct its |
| own unwind information, usually from legacy unwind directives. */ |
| |
| /* Construct a new INSN structure and add it to the end of the insn list |
| for the currently active FDE. */ |
| |
| static struct cfi_insn_data * |
| alloc_cfi_insn_data (void) |
| { |
| struct cfi_insn_data *insn = xcalloc (1, sizeof (struct cfi_insn_data)); |
| |
| *cur_fde_data->last = insn; |
| cur_fde_data->last = &insn->next; |
| |
| return insn; |
| } |
| |
| /* Construct a new FDE structure that begins at LABEL. */ |
| |
| void |
| cfi_new_fde (symbolS *label) |
| { |
| struct fde_entry *fde = alloc_fde_entry (); |
| fde->start_address = label; |
| last_address = label; |
| } |
| |
| /* End the currently open FDE. */ |
| |
| void |
| cfi_end_fde (symbolS *label) |
| { |
| cur_fde_data->end_address = label; |
| cur_fde_data = NULL; |
| } |
| |
| /* Set the return column for the current FDE. */ |
| |
| void |
| cfi_set_return_column (unsigned regno) |
| { |
| cur_fde_data->return_column = regno; |
| } |
| |
| /* Universal functions to store new instructions. */ |
| |
| static void |
| cfi_add_CFA_insn(int insn) |
| { |
| struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| |
| insn_ptr->insn = insn; |
| } |
| |
| static void |
| cfi_add_CFA_insn_reg (int insn, unsigned regno) |
| { |
| struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| |
| insn_ptr->insn = insn; |
| insn_ptr->u.r = regno; |
| } |
| |
| static void |
| cfi_add_CFA_insn_offset (int insn, offsetT offset) |
| { |
| struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| |
| insn_ptr->insn = insn; |
| insn_ptr->u.i = offset; |
| } |
| |
| static void |
| cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2) |
| { |
| struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| |
| insn_ptr->insn = insn; |
| insn_ptr->u.rr.reg1 = reg1; |
| insn_ptr->u.rr.reg2 = reg2; |
| } |
| |
| static void |
| cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset) |
| { |
| struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); |
| |
| insn_ptr->insn = insn; |
| insn_ptr->u.ri.reg = regno; |
| insn_ptr->u.ri.offset = offset; |
| } |
| |
| /* Add a CFI insn to advance the PC from the last address to LABEL. */ |
| |
| void |
| cfi_add_advance_loc (symbolS *label) |
| { |
| struct cfi_insn_data *insn = alloc_cfi_insn_data (); |
| |
| insn->insn = DW_CFA_advance_loc; |
| insn->u.ll.lab1 = last_address; |
| insn->u.ll.lab2 = label; |
| |
| last_address = label; |
| } |
| |
| /* Add a DW_CFA_offset record to the CFI data. */ |
| |
| void |
| cfi_add_CFA_offset (unsigned regno, offsetT offset) |
| { |
| unsigned int abs_data_align; |
| |
| cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset); |
| |
| abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0 |
| ? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT); |
| if (offset % abs_data_align) |
| as_bad (_("register save offset not a multiple of %u"), abs_data_align); |
| } |
| |
| /* Add a DW_CFA_def_cfa record to the CFI data. */ |
| |
| void |
| cfi_add_CFA_def_cfa (unsigned regno, offsetT offset) |
| { |
| cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset); |
| cur_cfa_offset = offset; |
| } |
| |
| /* Add a DW_CFA_register record to the CFI data. */ |
| |
| void |
| cfi_add_CFA_register (unsigned reg1, unsigned reg2) |
| { |
| cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2); |
| } |
| |
| /* Add a DW_CFA_def_cfa_register record to the CFI data. */ |
| |
| void |
| cfi_add_CFA_def_cfa_register (unsigned regno) |
| { |
| cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno); |
| } |
| |
| /* Add a DW_CFA_def_cfa_offset record to the CFI data. */ |
| |
| void |
| cfi_add_CFA_def_cfa_offset (offsetT offset) |
| { |
| cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset); |
| cur_cfa_offset = offset; |
| } |
| |
| void |
| cfi_add_CFA_restore (unsigned regno) |
| { |
| cfi_add_CFA_insn_reg (DW_CFA_restore, regno); |
| } |
| |
| void |
| cfi_add_CFA_undefined (unsigned regno) |
| { |
| cfi_add_CFA_insn_reg (DW_CFA_undefined, regno); |
| } |
| |
| void |
| cfi_add_CFA_same_value (unsigned regno) |
| { |
| cfi_add_CFA_insn_reg (DW_CFA_same_value, regno); |
| } |
| |
| void |
| cfi_add_CFA_remember_state (void) |
| { |
| struct cfa_save_data *p; |
| |
| cfi_add_CFA_insn (DW_CFA_remember_state); |
| |
| p = xmalloc (sizeof (*p)); |
| p->cfa_offset = cur_cfa_offset; |
| p->next = cfa_save_stack; |
| cfa_save_stack = p; |
| } |
| |
| void |
| cfi_add_CFA_restore_state (void) |
| { |
| struct cfa_save_data *p; |
| |
| cfi_add_CFA_insn (DW_CFA_restore_state); |
| |
| p = cfa_save_stack; |
| if (p) |
| { |
| cur_cfa_offset = p->cfa_offset; |
| cfa_save_stack = p->next; |
| free (p); |
| } |
| else |
| as_bad (_("CFI state restore without previous remember")); |
| } |
| |
| |
| /* Parse CFI assembler directives. */ |
| |
| static void dot_cfi (int); |
| static void dot_cfi_escape (int); |
| static void dot_cfi_startproc (int); |
| static void dot_cfi_endproc (int); |
| |
| /* 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 |
| |
| const pseudo_typeS cfi_pseudo_table[] = |
| { |
| { "cfi_startproc", dot_cfi_startproc, 0 }, |
| { "cfi_endproc", dot_cfi_endproc, 0 }, |
| { "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa }, |
| { "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register }, |
| { "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset }, |
| { "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset }, |
| { "cfi_offset", dot_cfi, DW_CFA_offset }, |
| { "cfi_rel_offset", dot_cfi, CFI_rel_offset }, |
| { "cfi_register", dot_cfi, DW_CFA_register }, |
| { "cfi_return_column", dot_cfi, CFI_return_column }, |
| { "cfi_restore", dot_cfi, DW_CFA_restore }, |
| { "cfi_undefined", dot_cfi, DW_CFA_undefined }, |
| { "cfi_same_value", dot_cfi, DW_CFA_same_value }, |
| { "cfi_remember_state", dot_cfi, DW_CFA_remember_state }, |
| { "cfi_restore_state", dot_cfi, DW_CFA_restore_state }, |
| { "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save }, |
| { "cfi_escape", dot_cfi_escape, 0 }, |
| { "cfi_signal_frame", dot_cfi, CFI_signal_frame }, |
| { NULL, NULL, 0 } |
| }; |
| |
| static void |
| cfi_parse_separator (void) |
| { |
| SKIP_WHITESPACE (); |
| if (*input_line_pointer == ',') |
| input_line_pointer++; |
| else |
| as_bad (_("missing separator")); |
| } |
| |
| static unsigned |
| cfi_parse_reg (void) |
| { |
| int regno; |
| expressionS exp; |
| |
| #ifdef tc_regname_to_dw2regnum |
| SKIP_WHITESPACE (); |
| if (is_name_beginner (*input_line_pointer) |
| || (*input_line_pointer == '%' |
| && is_name_beginner (*++input_line_pointer))) |
| { |
| char *name, c; |
| |
| name = input_line_pointer; |
| c = get_symbol_end (); |
| |
| if ((regno = tc_regname_to_dw2regnum (name)) < 0) |
| { |
| as_bad (_("bad register expression")); |
| regno = 0; |
| } |
| |
| *input_line_pointer = c; |
| return regno; |
| } |
| #endif |
| |
| expression_and_evaluate (&exp); |
| switch (exp.X_op) |
| { |
| case O_register: |
| case O_constant: |
| regno = exp.X_add_number; |
| break; |
| |
| default: |
| as_bad (_("bad register expression")); |
| 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")); |
| ignore_rest_of_line (); |
| 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: |
| for (;;) |
| { |
| reg1 = cfi_parse_reg (); |
| cfi_add_CFA_restore (reg1); |
| SKIP_WHITESPACE (); |
| if (*input_line_pointer != ',') |
| break; |
| ++input_line_pointer; |
| } |
| break; |
| |
| case DW_CFA_undefined: |
| for (;;) |
| { |
| reg1 = cfi_parse_reg (); |
| cfi_add_CFA_undefined (reg1); |
| SKIP_WHITESPACE (); |
| if (*input_line_pointer != ',') |
| break; |
| ++input_line_pointer; |
| } |
| 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; |
| |
| case CFI_signal_frame: |
| cur_fde_data->signal_frame = 1; |
| 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")); |
| ignore_rest_of_line (); |
| 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; |
| |
| --input_line_pointer; |
| demand_empty_rest_of_line (); |
| } |
| |
| 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)")); |
| ignore_rest_of_line (); |
| 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 (); |
| |
| cur_cfa_offset = 0; |
| 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")); |
| ignore_rest_of_line (); |
| return; |
| } |
| |
| cfi_end_fde (symbol_temp_new_now ()); |
| |
| demand_empty_rest_of_line (); |
| } |
| |
| |
| /* 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_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT); |
| } |
| 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 / DWARF2_CIE_DATA_ALIGNMENT); |
| } |
| 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'); |
| if (cie->signal_frame) |
| out_one ('S'); |
| out_one (0); |
| out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */ |
| out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */ |
| if (DW_CIE_VERSION == 1) /* Return column. */ |
| out_one (cie->return_column); |
| else |
| out_uleb128 (cie->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, DW_CFA_nop, 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, DW_CFA_nop, 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 |
| || cie->signal_frame != fde->signal_frame) |
| 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: |
| case DW_CFA_remember_state: |
| /* We reached the first advance/remember 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, |
| remember, or escape. */ |
| if (i == cie->last |
| && (!j |
| || j->insn == DW_CFA_advance_loc |
| || j->insn == DW_CFA_remember_state |
| || j->insn == CFI_escape)) |
| { |
| *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->signal_frame = fde->signal_frame; |
| cie->first = fde->data; |
| |
| for (i = cie->first; i ; i = i->next) |
| if (i->insn == DW_CFA_advance_loc |
| || i->insn == DW_CFA_remember_state |
| || i->insn == CFI_escape) |
| 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); |
| bfd_set_section_flags (stdoutput, cfi_seg, |
| SEC_ALLOC | SEC_LOAD | SEC_DATA | SEC_READONLY); |
| 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; |
| } |