diff options
Diffstat (limited to 'contrib/binutils/gas/dw2gencfi.c')
| -rw-r--r-- | contrib/binutils/gas/dw2gencfi.c | 1042 |
1 files changed, 1042 insertions, 0 deletions
diff --git a/contrib/binutils/gas/dw2gencfi.c b/contrib/binutils/gas/dw2gencfi.c new file mode 100644 index 0000000..ff0aa35 --- /dev/null +++ b/contrib/binutils/gas/dw2gencfi.c @@ -0,0 +1,1042 @@ +/* dw2gencfi.c - Support for generating Dwarf2 CFI information. + Copyright 2003 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, 59 Temple Place - Suite 330, Boston, MA + 02111-1307, 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 +# ifdef BFD_ASSEMBLER +# define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2) +# else +# define EH_FRAME_ALIGNMENT 2 +# endif +#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; +}; + +struct cie_entry +{ + struct cie_entry *next; + symbolS *start_address; + unsigned int return_column; + 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); + } +} + + +/* 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 + +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 }, + { 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 (&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")); + 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; +} |
