/* dw2gencfi.c - Support for generating Dwarf2 CFI information. Copyright (C) 2003-2024 Free Software Foundation, Inc. Contributed by Michal Ludvig 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. */ #include "as.h" #include "dw2gencfi.h" #include "subsegs.h" #include "dwarf2dbg.h" #include "gen-sframe.h" #ifdef TARGET_USE_CFIPOP /* By default, use difference expressions if DIFF_EXPR_OK is defined. */ #ifndef CFI_DIFF_EXPR_OK # ifdef DIFF_EXPR_OK # define CFI_DIFF_EXPR_OK 1 # else # define CFI_DIFF_EXPR_OK 0 # endif #endif #ifndef CFI_DIFF_LSDA_OK #define CFI_DIFF_LSDA_OK CFI_DIFF_EXPR_OK #endif #if CFI_DIFF_EXPR_OK == 1 && CFI_DIFF_LSDA_OK == 0 # error "CFI_DIFF_EXPR_OK should imply CFI_DIFF_LSDA_OK" #endif /* 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 /* By default, use 32-bit relocations from .eh_frame into .text. */ #ifndef DWARF2_FDE_RELOC_SIZE #define DWARF2_FDE_RELOC_SIZE 4 #endif /* By default, use a read-only .eh_frame section. */ #ifndef DWARF2_EH_FRAME_READ_ONLY #define DWARF2_EH_FRAME_READ_ONLY SEC_READONLY #endif #ifndef EH_FRAME_ALIGNMENT #define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2) #endif #define EH_FRAME_LINKONCE (SUPPORT_FRAME_LINKONCE || compact_eh \ || TARGET_MULTIPLE_EH_FRAME_SECTIONS) #ifndef DWARF2_FORMAT #define DWARF2_FORMAT(SEC) dwarf2_format_32bit #endif #ifndef DWARF2_ADDR_SIZE #define DWARF2_ADDR_SIZE(bfd) (bfd_arch_bits_per_address (bfd) / 8) #endif #if MULTIPLE_FRAME_SECTIONS #define CUR_SEG(structp) structp->cur_seg #define SET_CUR_SEG(structp, seg) structp->cur_seg = seg #define HANDLED(structp) structp->handled #define SET_HANDLED(structp, val) structp->handled = val #else #define CUR_SEG(structp) NULL #define SET_CUR_SEG(structp, seg) (void) (0 && seg) #define HANDLED(structp) 0 #define SET_HANDLED(structp, val) (void) (0 && val) #endif #ifndef tc_cfi_reloc_for_encoding #define tc_cfi_reloc_for_encoding(e) BFD_RELOC_NONE #endif /* Targets which support SFrame format will define this and return true. */ #ifndef support_sframe_p # define support_sframe_p() false #endif /* Private segment collection list. */ struct dwcfi_seg_list { segT seg; int subseg; char * seg_name; }; #ifdef SUPPORT_COMPACT_EH static bool compact_eh; #else #define compact_eh 0 #endif static htab_t dwcfi_hash; /* 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 unsigned int encoding_size (unsigned char encoding) { if (encoding == DW_EH_PE_omit) return 0; switch (encoding & 0x7) { case 0: return bfd_get_arch_size (stdoutput) == 64 ? 8 : 4; case DW_EH_PE_udata2: return 2; case DW_EH_PE_udata4: return 4; case DW_EH_PE_udata8: return 8; default: abort (); } } /* Emit expression EXP in ENCODING. If EMIT_ENCODING is true, first emit a byte containing ENCODING. */ static void emit_expr_encoded (expressionS *exp, int encoding, bool emit_encoding) { unsigned int size = encoding_size (encoding); bfd_reloc_code_real_type code; if (encoding == DW_EH_PE_omit) return; if (emit_encoding) out_one (encoding); code = tc_cfi_reloc_for_encoding (encoding); if (code != BFD_RELOC_NONE) { reloc_howto_type *howto = bfd_reloc_type_lookup (stdoutput, code); char *p = frag_more (size); gas_assert (size == (unsigned) howto->bitsize / 8); md_number_to_chars (p, 0, size); fix_new (frag_now, p - frag_now->fr_literal, size, exp->X_add_symbol, exp->X_add_number, howto->pc_relative, code); } else if ((encoding & 0x70) == DW_EH_PE_pcrel) { #if CFI_DIFF_EXPR_OK expressionS tmp = *exp; tmp.X_op = O_subtract; tmp.X_op_symbol = symbol_temp_new_now (); emit_expr (&tmp, size); #elif defined (tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (exp, size); #else abort (); #endif } else emit_expr (exp, size); } /* Build based on segment the derived .debug_... segment name containing origin segment's postfix name part. */ static char * get_debugseg_name (segT seg, const char *base_name) { const char * name; const char * dollar; const char * dot; if (!seg || (name = bfd_section_name (seg)) == NULL || *name == 0) return notes_strdup (base_name); dollar = strchr (name, '$'); dot = strchr (name + 1, '.'); if (!dollar && !dot) { if (!strcmp (base_name, ".eh_frame_entry") && strcmp (name, ".text") != 0) return notes_concat (base_name, ".", name, NULL); name = ""; } else if (!dollar) name = dot; else if (!dot) name = dollar; else if (dot < dollar) name = dot; else name = dollar; return notes_concat (base_name, name, NULL); } /* Allocate a dwcfi_seg_list structure. */ static struct dwcfi_seg_list * alloc_debugseg_item (segT seg, int subseg, char *name) { struct dwcfi_seg_list *r; r = notes_alloc (sizeof (*r) + strlen (name)); r->seg = seg; r->subseg = subseg; r->seg_name = name; return r; } static segT is_now_linkonce_segment (void) { if (compact_eh) return now_seg; if (TARGET_MULTIPLE_EH_FRAME_SECTIONS) return now_seg; if ((bfd_section_flags (now_seg) & (SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD | SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE | SEC_LINK_DUPLICATES_SAME_CONTENTS)) != 0) return now_seg; return NULL; } /* Generate debug... segment with same linkonce properties of based segment. */ static segT make_debug_seg (segT cseg, char *name, int sflags) { segT save_seg = now_seg; int save_subseg = now_subseg; segT r; flagword flags; r = subseg_new (name, 0); /* Check if code segment is marked as linked once. */ if (!cseg) flags = 0; else flags = (bfd_section_flags (cseg) & (SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD | SEC_LINK_DUPLICATES_ONE_ONLY | SEC_LINK_DUPLICATES_SAME_SIZE | SEC_LINK_DUPLICATES_SAME_CONTENTS)); /* Add standard section flags. */ flags |= sflags; /* Apply possibly linked once flags to new generated segment, too. */ if (!bfd_set_section_flags (r, flags)) as_bad (_("bfd_set_section_flags: %s"), bfd_errmsg (bfd_get_error ())); /* Restore to previous segment. */ if (save_seg != NULL) subseg_set (save_seg, save_subseg); return r; } static struct dwcfi_seg_list * dwcfi_hash_find (char *name) { return (struct dwcfi_seg_list *) str_hash_find (dwcfi_hash, name); } static struct dwcfi_seg_list * dwcfi_hash_find_or_make (segT cseg, const char *base_name, int flags) { struct dwcfi_seg_list *item; char *name; /* Initialize dwcfi_hash once. */ if (!dwcfi_hash) dwcfi_hash = str_htab_create (); name = get_debugseg_name (cseg, base_name); item = dwcfi_hash_find (name); if (!item) { item = alloc_debugseg_item (make_debug_seg (cseg, name, flags), 0, name); str_hash_insert (dwcfi_hash, item->seg_name, item, 0); } else notes_free (name); return item; } /* ??? Share this with dwarf2cfg.c. */ #ifndef TC_DWARF2_EMIT_OFFSET #define TC_DWARF2_EMIT_OFFSET generic_dwarf2_emit_offset /* Create an offset to .dwarf2_*. */ static void generic_dwarf2_emit_offset (symbolS *symbol, unsigned int size) { expressionS exp; exp.X_op = O_symbol; exp.X_add_symbol = symbol; exp.X_add_number = 0; emit_expr (&exp, size); } #endif struct cfi_escape_data { struct cfi_escape_data *next; expressionS exp; }; struct cie_entry { struct cie_entry *next; #if MULTIPLE_FRAME_SECTIONS segT cur_seg; #endif symbolS *start_address; unsigned int return_column; unsigned int signal_frame; unsigned char fde_encoding; unsigned char per_encoding; unsigned char lsda_encoding; expressionS personality; #ifdef tc_cie_entry_extras tc_cie_entry_extras #endif struct cfi_insn_data *first, *last; }; /* List of FDE entries. */ 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; /* 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 = XCNEW (struct fde_entry); frchain_now->frch_cfi_data = XCNEW (struct frch_cfi_data); frchain_now->frch_cfi_data->cur_fde_data = fde; *last_fde_data = fde; last_fde_data = &fde->next; SET_CUR_SEG (fde, is_now_linkonce_segment ()); SET_HANDLED (fde, 0); fde->last = &fde->data; fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN; fde->per_encoding = DW_EH_PE_omit; fde->lsda_encoding = DW_EH_PE_omit; fde->eh_header_type = EH_COMPACT_UNKNOWN; #ifdef tc_fde_entry_init_extra tc_fde_entry_init_extra (fde) #endif 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 bool cfi_sections_set = false; static int cfi_sections = CFI_EMIT_eh_frame; int all_cfi_sections = 0; static struct fde_entry *last_fde; static struct cfi_insn_data * alloc_cfi_insn_data (void) { struct cfi_insn_data *insn = XCNEW (struct cfi_insn_data); struct fde_entry *cur_fde_data = frchain_now->frch_cfi_data->cur_fde_data; *cur_fde_data->last = insn; cur_fde_data->last = &insn->next; SET_CUR_SEG (insn, is_now_linkonce_segment ()); 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; frchain_now->frch_cfi_data->last_address = label; } /* End the currently open FDE. */ void cfi_end_fde (symbolS *label) { frchain_now->frch_cfi_data->cur_fde_data->end_address = label; free (frchain_now->frch_cfi_data); frchain_now->frch_cfi_data = NULL; } /* Set the last FDE .*/ void cfi_set_last_fde (struct fde_entry *fde) { last_fde = fde; } /* Set the return column for the current FDE. */ void cfi_set_return_column (unsigned regno) { frchain_now->frch_cfi_data->cur_fde_data->return_column = regno; } void cfi_set_sections (void) { all_cfi_sections |= cfi_sections; frchain_now->frch_cfi_data->cur_fde_data->sections = all_cfi_sections; cfi_sections_set = true; } /* 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 = frchain_now->frch_cfi_data->last_address; insn->u.ll.lab2 = label; frchain_now->frch_cfi_data->last_address = label; } /* Add a CFI insn to label the current position in the CFI segment. */ void cfi_add_label (const char *name) { unsigned int len = strlen (name) + 1; struct cfi_insn_data *insn = alloc_cfi_insn_data (); insn->insn = CFI_label; obstack_grow (¬es, name, len); insn->u.sym_name = (char *) obstack_finish (¬es); } /* Add a DW_CFA_offset record to the CFI data. */ void cfi_add_CFA_offset (unsigned regno, offsetT offset) { unsigned int abs_data_align; gas_assert (DWARF2_CIE_DATA_ALIGNMENT != 0); 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_val_offset record to the CFI data. */ void cfi_add_CFA_val_offset (unsigned regno, offsetT offset) { unsigned int abs_data_align; gas_assert (DWARF2_CIE_DATA_ALIGNMENT != 0); cfi_add_CFA_insn_reg_offset (DW_CFA_val_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); frchain_now->frch_cfi_data->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); frchain_now->frch_cfi_data->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 = XNEW (struct cfa_save_data); p->cfa_offset = frchain_now->frch_cfi_data->cur_cfa_offset; p->next = frchain_now->frch_cfi_data->cfa_save_stack; frchain_now->frch_cfi_data->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 = frchain_now->frch_cfi_data->cfa_save_stack; if (p) { frchain_now->frch_cfi_data->cur_cfa_offset = p->cfa_offset; frchain_now->frch_cfi_data->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); static void dot_cfi_fde_data (int); static void dot_cfi_personality (int); static void dot_cfi_personality_id (int); static void dot_cfi_lsda (int); static void dot_cfi_val_encoded_addr (int); static void dot_cfi_inline_lsda (int); static void dot_cfi_label (int); const pseudo_typeS cfi_pseudo_table[] = { { "cfi_sections", dot_cfi_sections, 0 }, { "cfi_startproc", dot_cfi_startproc, 0 }, { "cfi_endproc", dot_cfi_endproc, 0 }, { "cfi_fde_data", dot_cfi_fde_data, 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_negate_ra_state", dot_cfi, DW_CFA_AARCH64_negate_ra_state }, { "cfi_escape", dot_cfi_escape, 0 }, { "cfi_signal_frame", dot_cfi, CFI_signal_frame }, { "cfi_personality", dot_cfi_personality, 0 }, { "cfi_personality_id", dot_cfi_personality_id, 0 }, { "cfi_lsda", dot_cfi_lsda, 0 }, { "cfi_val_encoded_addr", dot_cfi_val_encoded_addr, 0 }, { "cfi_inline_lsda", dot_cfi_inline_lsda, 0 }, { "cfi_label", dot_cfi_label, 0 }, { "cfi_val_offset", dot_cfi, DW_CFA_val_offset }, { NULL, NULL, 0 } }; static void cfi_parse_separator (void) { SKIP_WHITESPACE (); if (*input_line_pointer == ',') input_line_pointer++; else as_bad (_("missing separator")); } #ifndef tc_parse_to_dw2regnum static void tc_parse_to_dw2regnum (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; c = get_symbol_name (& name); exp->X_op = O_constant; exp->X_add_number = tc_regname_to_dw2regnum (name); restore_line_pointer (c); } else # endif expression_and_evaluate (exp); } #endif static unsigned cfi_parse_reg (void) { int regno; expressionS exp; tc_parse_to_dw2regnum (&exp); switch (exp.X_op) { case O_register: case O_constant: regno = exp.X_add_number; break; default: regno = -1; break; } if (regno < 0) { as_bad (_("bad register expression")); regno = 0; } return regno; } static offsetT cfi_parse_const (void) { return get_absolute_expression (); } static void dot_cfi (int arg) { offsetT offset; unsigned reg1, reg2; if (frchain_now->frch_cfi_data == NULL) { 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 (frchain_now->frch_cfi_data->last_address) != frag_now || (S_GET_VALUE (frchain_now->frch_cfi_data->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 DW_CFA_val_offset: reg1 = cfi_parse_reg (); cfi_parse_separator (); offset = cfi_parse_const (); cfi_add_CFA_val_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 - frchain_now->frch_cfi_data->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 (frchain_now->frch_cfi_data->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: frchain_now->frch_cfi_data->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 (frchain_now->frch_cfi_data == NULL) { 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 (frchain_now->frch_cfi_data->last_address) != frag_now || (S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ())) cfi_add_advance_loc (symbol_temp_new_now ()); tail = &head; do { e = XNEW (struct cfi_escape_data); 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_personality (int ignored ATTRIBUTE_UNUSED) { struct fde_entry *fde; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } fde = frchain_now->frch_cfi_data->cur_fde_data; encoding = cfi_parse_const (); if (encoding == DW_EH_PE_omit) { demand_empty_rest_of_line (); fde->per_encoding = encoding; return; } if ((encoding & 0xff) != encoding || ((((encoding & 0x70) != 0 #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) && tc_cfi_reloc_for_encoding (encoding) == BFD_RELOC_NONE)) { as_bad (_("invalid or unsupported encoding in .cfi_personality")); ignore_rest_of_line (); return; } if (*input_line_pointer++ != ',') { as_bad (_(".cfi_personality requires encoding and symbol arguments")); ignore_rest_of_line (); return; } expression_and_evaluate (&fde->personality); switch (fde->personality.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) == DW_EH_PE_pcrel) encoding = DW_EH_PE_omit; break; default: encoding = DW_EH_PE_omit; break; } fde->per_encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong second argument to .cfi_personality")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } static void dot_cfi_lsda (int ignored ATTRIBUTE_UNUSED) { struct fde_entry *fde; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } fde = frchain_now->frch_cfi_data->cur_fde_data; encoding = cfi_parse_const (); if (encoding == DW_EH_PE_omit) { demand_empty_rest_of_line (); fde->lsda_encoding = encoding; return; } if ((encoding & 0xff) != encoding || ((((encoding & 0x70) != 0 #if CFI_DIFF_LSDA_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) && tc_cfi_reloc_for_encoding (encoding) == BFD_RELOC_NONE)) { as_bad (_("invalid or unsupported encoding in .cfi_lsda")); ignore_rest_of_line (); return; } if (*input_line_pointer++ != ',') { as_bad (_(".cfi_lsda requires encoding and symbol arguments")); ignore_rest_of_line (); return; } fde->lsda_encoding = encoding; expression_and_evaluate (&fde->lsda); switch (fde->lsda.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) == DW_EH_PE_pcrel) encoding = DW_EH_PE_omit; break; default: encoding = DW_EH_PE_omit; break; } fde->lsda_encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong second argument to .cfi_lsda")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } static void dot_cfi_val_encoded_addr (int ignored ATTRIBUTE_UNUSED) { struct cfi_insn_data *insn_ptr; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { 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 (frchain_now->frch_cfi_data->last_address) != frag_now || (S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ())) cfi_add_advance_loc (symbol_temp_new_now ()); insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = CFI_val_encoded_addr; insn_ptr->u.ea.reg = cfi_parse_reg (); cfi_parse_separator (); encoding = cfi_parse_const (); if ((encoding & 0xff) != encoding || ((encoding & 0x70) != 0 #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) { as_bad (_("invalid or unsupported encoding in .cfi_lsda")); encoding = DW_EH_PE_omit; } cfi_parse_separator (); expression_and_evaluate (&insn_ptr->u.ea.exp); switch (insn_ptr->u.ea.exp.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) != DW_EH_PE_pcrel) break; /* Fall through. */ default: encoding = DW_EH_PE_omit; break; } insn_ptr->u.ea.encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong third argument to .cfi_val_encoded_addr")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } static void dot_cfi_label (int ignored ATTRIBUTE_UNUSED) { char *name; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } name = read_symbol_name (); if (name == NULL) return; /* If the last address was not at the current PC, advance to current. */ if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now || (S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ())) cfi_add_advance_loc (symbol_temp_new_now ()); cfi_add_label (name); free (name); demand_empty_rest_of_line (); } void dot_cfi_sections (int ignored ATTRIBUTE_UNUSED) { int sections = 0; SKIP_WHITESPACE (); if (is_name_beginner (*input_line_pointer) || *input_line_pointer == '"') while (1) { char * saved_ilp; char *name, c; saved_ilp = input_line_pointer; c = get_symbol_name (& name); if (startswith (name, ".eh_frame") && name[9] != '_') sections |= CFI_EMIT_eh_frame; else if (startswith (name, ".debug_frame")) sections |= CFI_EMIT_debug_frame; #if SUPPORT_COMPACT_EH else if (startswith (name, ".eh_frame_entry")) { compact_eh = true; sections |= CFI_EMIT_eh_frame_compact; } #endif #ifdef tc_cfi_section_name else if (strcmp (name, tc_cfi_section_name) == 0) sections |= CFI_EMIT_target; #endif else if (startswith (name, ".sframe")) sections |= CFI_EMIT_sframe; else { *input_line_pointer = c; input_line_pointer = saved_ilp; break; } restore_line_pointer (c); SKIP_WHITESPACE (); if (*input_line_pointer == ',') { name = input_line_pointer++; SKIP_WHITESPACE (); if (!is_name_beginner (*input_line_pointer) && *input_line_pointer != '"') { input_line_pointer = name; break; } } else if (is_name_beginner (*input_line_pointer) || *input_line_pointer == '"') break; } demand_empty_rest_of_line (); if (cfi_sections_set && (sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact)) && ((cfi_sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact)) != (sections & (CFI_EMIT_eh_frame | CFI_EMIT_eh_frame_compact)))) as_bad (_("inconsistent uses of .cfi_sections")); cfi_sections = sections; } static void dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED) { int simple = 0; if (frchain_now->frch_cfi_data != NULL) { 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) || *input_line_pointer == '"') { char * saved_ilp = input_line_pointer; char *name, c; c = get_symbol_name (& name); if (strcmp (name, "simple") == 0) { simple = 1; restore_line_pointer (c); } else input_line_pointer = saved_ilp; } demand_empty_rest_of_line (); cfi_set_sections (); frchain_now->frch_cfi_data->cur_cfa_offset = 0; if (!simple) tc_cfi_frame_initial_instructions (); if ((all_cfi_sections & CFI_EMIT_target) != 0) tc_cfi_startproc (); } static void dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED) { if (frchain_now->frch_cfi_data == NULL) { as_bad (_(".cfi_endproc without corresponding .cfi_startproc")); ignore_rest_of_line (); return; } cfi_set_last_fde (frchain_now->frch_cfi_data->cur_fde_data); cfi_end_fde (symbol_temp_new_now ()); demand_empty_rest_of_line (); if ((all_cfi_sections & CFI_EMIT_target) != 0) tc_cfi_endproc (last_fde); } static segT get_cfi_seg (segT cseg, const char *base, flagword flags, int align) { /* Exclude .debug_frame sections for Compact EH. */ if (SUPPORT_FRAME_LINKONCE || ((flags & SEC_DEBUGGING) == 0 && compact_eh) || ((flags & SEC_DEBUGGING) == 0 && TARGET_MULTIPLE_EH_FRAME_SECTIONS)) { segT iseg = cseg; struct dwcfi_seg_list *l; l = dwcfi_hash_find_or_make (cseg, base, flags); cseg = l->seg; subseg_set (cseg, l->subseg); if (TARGET_MULTIPLE_EH_FRAME_SECTIONS && (flags & DWARF2_EH_FRAME_READ_ONLY)) { const frchainS *ifrch = seg_info (iseg)->frchainP; const frchainS *frch = seg_info (cseg)->frchainP; expressionS exp; exp.X_op = O_symbol; exp.X_add_symbol = (symbolS *) local_symbol_make (cseg->name, cseg, frch->frch_root, 0); exp.X_add_number = 0; subseg_set (iseg, ifrch->frch_subseg); fix_new_exp (ifrch->frch_root, 0, 0, &exp, 0, BFD_RELOC_NONE); /* Restore the original segment info. */ subseg_set (cseg, l->subseg); } } else { cseg = subseg_new (base, 0); bfd_set_section_flags (cseg, flags); } record_alignment (cseg, align); return cseg; } #if SUPPORT_COMPACT_EH static void dot_cfi_personality_id (int ignored ATTRIBUTE_UNUSED) { struct fde_entry *fde; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } fde = frchain_now->frch_cfi_data->cur_fde_data; fde->personality_id = cfi_parse_const (); demand_empty_rest_of_line (); if (fde->personality_id == 0 || fde->personality_id > 3) { as_bad (_("wrong argument to .cfi_personality_id")); return; } } static void dot_cfi_fde_data (int ignored ATTRIBUTE_UNUSED) { if (frchain_now->frch_cfi_data == NULL) { as_bad (_(".cfi_fde_data without corresponding .cfi_startproc")); ignore_rest_of_line (); return; } cfi_set_last_fde (frchain_now->frch_cfi_data->cur_fde_data); if ((all_cfi_sections & CFI_EMIT_target) != 0 || (all_cfi_sections & CFI_EMIT_eh_frame_compact) != 0) { struct cfi_escape_data *head, **tail, *e; int num_ops = 0; tail = &head; if (!is_it_end_of_statement ()) { num_ops = 0; do { e = XNEW (struct cfi_escape_data); do_parse_cons_expression (&e->exp, 1); *tail = e; tail = &e->next; num_ops++; } while (*input_line_pointer++ == ','); --input_line_pointer; } *tail = NULL; if (last_fde->lsda_encoding != DW_EH_PE_omit) last_fde->eh_header_type = EH_COMPACT_HAS_LSDA; else if (num_ops <= 3 && last_fde->per_encoding == DW_EH_PE_omit) last_fde->eh_header_type = EH_COMPACT_INLINE; else last_fde->eh_header_type = EH_COMPACT_OUTLINE; if (last_fde->eh_header_type == EH_COMPACT_INLINE) num_ops = 3; last_fde->eh_data_size = num_ops; last_fde->eh_data = XNEWVEC (bfd_byte, num_ops); num_ops = 0; while (head) { e = head; head = e->next; last_fde->eh_data[num_ops++] = e->exp.X_add_number; free (e); } if (last_fde->eh_header_type == EH_COMPACT_INLINE) while (num_ops < 3) last_fde->eh_data[num_ops++] = tc_compact_eh_opcode_stop; } demand_empty_rest_of_line (); } /* Function to emit the compact unwinding opcodes stored in the fde's eh_data field. The end of the opcode data will be padded to the value in align. */ static void output_compact_unwind_data (struct fde_entry *fde, int align) { int data_size = fde->eh_data_size + 2; int align_padding; int amask; char *p; fde->eh_loc = symbol_temp_new_now (); p = frag_more (1); if (fde->personality_id != 0) *p = fde->personality_id; else if (fde->per_encoding != DW_EH_PE_omit) { *p = 0; emit_expr_encoded (&fde->personality, fde->per_encoding, false); data_size += encoding_size (fde->per_encoding); } else *p = 1; amask = (1 << align) - 1; align_padding = ((data_size + amask) & ~amask) - data_size; p = frag_more (fde->eh_data_size + 1 + align_padding); memcpy (p, fde->eh_data, fde->eh_data_size); p += fde->eh_data_size; while (align_padding-- > 0) *(p++) = tc_compact_eh_opcode_pad; *(p++) = tc_compact_eh_opcode_stop; fde->eh_header_type = EH_COMPACT_OUTLINE_DONE; } /* Handle the .cfi_inline_lsda directive. */ static void dot_cfi_inline_lsda (int ignored ATTRIBUTE_UNUSED) { segT ccseg; int align; long max_alignment = 28; if (!last_fde) { as_bad (_("unexpected .cfi_inline_lsda")); ignore_rest_of_line (); return; } if ((last_fde->sections & CFI_EMIT_eh_frame_compact) == 0) { as_bad (_(".cfi_inline_lsda not valid for this frame")); ignore_rest_of_line (); return; } if (last_fde->eh_header_type != EH_COMPACT_UNKNOWN && last_fde->eh_header_type != EH_COMPACT_HAS_LSDA) { as_bad (_(".cfi_inline_lsda seen for frame without .cfi_lsda")); ignore_rest_of_line (); return; } #ifdef md_flush_pending_output md_flush_pending_output (); #endif align = get_absolute_expression (); if (align > max_alignment) { align = max_alignment; as_bad (_("Alignment too large: %d. assumed."), align); } else if (align < 0) { as_warn (_("Alignment negative: 0 assumed.")); align = 0; } demand_empty_rest_of_line (); ccseg = CUR_SEG (last_fde); /* Open .gnu_extab section. */ get_cfi_seg (ccseg, ".gnu_extab", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), 1); frag_align (align, 0, 0); record_alignment (now_seg, align); if (last_fde->eh_header_type == EH_COMPACT_HAS_LSDA) output_compact_unwind_data (last_fde, align); cfi_set_last_fde (NULL); return; } #else /* !SUPPORT_COMPACT_EH */ static void dot_cfi_inline_lsda (int ignored ATTRIBUTE_UNUSED) { as_bad (_(".cfi_inline_lsda is not supported for this target")); ignore_rest_of_line (); } static void dot_cfi_fde_data (int ignored ATTRIBUTE_UNUSED) { as_bad (_(".cfi_fde_data is not supported for this target")); ignore_rest_of_line (); } static void dot_cfi_personality_id (int ignored ATTRIBUTE_UNUSED) { as_bad (_(".cfi_personality_id is not supported for this target")); ignore_rest_of_line (); } #endif 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 == 0) ; else if (scaled <= 0x3F) out_one (DW_CFA_advance_loc + scaled); else if (scaled <= 0xFF) { out_one (DW_CFA_advance_loc1); out_one (scaled); } else if (scaled <= 0xFFFF) { out_one (DW_CFA_advance_loc2); out_two (scaled); } else { out_one (DW_CFA_advance_loc4); out_four (scaled); } } 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. Call frag_grow with the sum of room needed by frag_more and frag_var to preallocate space ensuring that the DW_CFA_advance_loc4 is in the fixed part of the rs_cfa frag, so that the relax machinery can remove the advance_loc should it advance by zero. */ frag_grow (5); *frag_more (1) = DW_CFA_advance_loc4; 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_val_offset: regno = insn->u.ri.reg; offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT; if (offset < 0) { out_one (DW_CFA_val_offset_sf); out_uleb128 (regno); out_sleb128 (offset); } else { out_one (DW_CFA_val_offset); 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; } case CFI_val_encoded_addr: { unsigned encoding = insn->u.ea.encoding; offsetT enc_size; if (encoding == DW_EH_PE_omit) break; out_one (DW_CFA_val_expression); out_uleb128 (insn->u.ea.reg); switch (encoding & 0x7) { case DW_EH_PE_absptr: enc_size = DWARF2_ADDR_SIZE (stdoutput); break; case DW_EH_PE_udata2: enc_size = 2; break; case DW_EH_PE_udata4: enc_size = 4; break; case DW_EH_PE_udata8: enc_size = 8; break; default: abort (); } /* If the user has requested absolute encoding, then use the smaller DW_OP_addr encoding. */ if (insn->u.ea.encoding == DW_EH_PE_absptr) { out_uleb128 (1 + enc_size); out_one (DW_OP_addr); } else { out_uleb128 (1 + 1 + enc_size); out_one (DW_OP_GNU_encoded_addr); out_one (encoding); if ((encoding & 0x70) == DW_EH_PE_pcrel) { #if CFI_DIFF_EXPR_OK insn->u.ea.exp.X_op = O_subtract; insn->u.ea.exp.X_op_symbol = symbol_temp_new_now (); #elif defined (tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (&insn->u.ea.exp, enc_size); break; #else abort (); #endif } } emit_expr (&insn->u.ea.exp, enc_size); } break; case CFI_label: colon (insn->u.sym_name); break; default: abort (); } } static void output_cie (struct cie_entry *cie, bool eh_frame, int align) { symbolS *after_size_address, *end_address; expressionS exp; struct cfi_insn_data *i; offsetT augmentation_size; int enc; enum dwarf2_format fmt = DWARF2_FORMAT (now_seg); 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; if (eh_frame || fmt == dwarf2_format_32bit) emit_expr (&exp, 4); /* Length. */ else { if (fmt == dwarf2_format_64bit) out_four (-1); emit_expr (&exp, 8); /* Length. */ } symbol_set_value_now (after_size_address); if (eh_frame) out_four (0); /* CIE id. */ else { out_four (-1); /* CIE id. */ if (fmt != dwarf2_format_32bit) out_four (-1); } out_one (flag_dwarf_cie_version); /* Version. */ if (eh_frame) { out_one ('z'); /* Augmentation. */ if (cie->per_encoding != DW_EH_PE_omit) out_one ('P'); if (cie->lsda_encoding != DW_EH_PE_omit) out_one ('L'); out_one ('R'); #ifdef tc_output_cie_extra tc_output_cie_extra (cie); #endif } if (cie->signal_frame) out_one ('S'); out_one (0); if (flag_dwarf_cie_version >= 4) { /* For now we are assuming a flat address space with 4 or 8 byte addresses. */ int address_size = dwarf2_format_32bit ? 4 : 8; out_one (address_size); /* Address size. */ out_one (0); /* Segment size. */ } out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */ out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */ if (flag_dwarf_cie_version == 1) /* Return column. */ { if ((cie->return_column & 0xff) != cie->return_column) as_bad (_("return column number %d overflows in CIE version 1"), cie->return_column); out_one (cie->return_column); } else out_uleb128 (cie->return_column); if (eh_frame) { augmentation_size = 1 + (cie->lsda_encoding != DW_EH_PE_omit); if (cie->per_encoding != DW_EH_PE_omit) augmentation_size += 1 + encoding_size (cie->per_encoding); out_uleb128 (augmentation_size); /* Augmentation size. */ emit_expr_encoded (&cie->personality, cie->per_encoding, true); if (cie->lsda_encoding != DW_EH_PE_omit) out_one (cie->lsda_encoding); } switch (DWARF2_FDE_RELOC_SIZE) { case 2: enc = DW_EH_PE_sdata2; break; case 4: enc = DW_EH_PE_sdata4; break; case 8: enc = DW_EH_PE_sdata8; break; default: abort (); } #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr enc |= DW_EH_PE_pcrel; #endif #ifdef DWARF2_FDE_RELOC_ENCODING /* Allow target to override encoding. */ enc = DWARF2_FDE_RELOC_ENCODING (enc); #endif cie->fde_encoding = enc; if (eh_frame) out_one (enc); if (cie->first) { for (i = cie->first; i != cie->last; i = i->next) { if (CUR_SEG (i) != CUR_SEG (cie)) continue; output_cfi_insn (i); } } frag_align (align, DW_CFA_nop, 0); symbol_set_value_now (end_address); } static void output_fde (struct fde_entry *fde, struct cie_entry *cie, bool eh_frame, struct cfi_insn_data *first, int align) { symbolS *after_size_address, *end_address; expressionS exp; offsetT augmentation_size; enum dwarf2_format fmt = DWARF2_FORMAT (now_seg); unsigned int offset_size; unsigned int addr_size; 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; if (eh_frame || fmt == dwarf2_format_32bit) offset_size = 4; else { if (fmt == dwarf2_format_64bit) out_four (-1); offset_size = 8; } emit_expr (&exp, offset_size); /* Length. */ symbol_set_value_now (after_size_address); if (eh_frame) { exp.X_op = O_subtract; exp.X_add_symbol = after_size_address; exp.X_op_symbol = cie->start_address; exp.X_add_number = 0; emit_expr (&exp, offset_size); /* CIE offset. */ } else { TC_DWARF2_EMIT_OFFSET (cie->start_address, offset_size); } exp.X_op = O_symbol; if (eh_frame) { bfd_reloc_code_real_type code = tc_cfi_reloc_for_encoding (cie->fde_encoding); addr_size = DWARF2_FDE_RELOC_SIZE; if (code != BFD_RELOC_NONE) { reloc_howto_type *howto = bfd_reloc_type_lookup (stdoutput, code); char *p = frag_more (addr_size); gas_assert (addr_size == (unsigned) howto->bitsize / 8); md_number_to_chars (p, 0, addr_size); fix_new (frag_now, p - frag_now->fr_literal, addr_size, fde->start_address, 0, howto->pc_relative, code); } else { exp.X_op = O_subtract; exp.X_add_number = 0; #if CFI_DIFF_EXPR_OK exp.X_add_symbol = fde->start_address; exp.X_op_symbol = symbol_temp_new_now (); emit_expr (&exp, addr_size); /* Code offset. */ #else exp.X_op = O_symbol; exp.X_add_symbol = fde->start_address; #if defined(tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (&exp, addr_size); /* Code offset. */ #else emit_expr (&exp, addr_size); /* Code offset. */ #endif #endif } } else { exp.X_add_number = 0; exp.X_add_symbol = fde->start_address; addr_size = DWARF2_ADDR_SIZE (stdoutput); emit_expr (&exp, addr_size); } exp.X_op = O_subtract; exp.X_add_symbol = fde->end_address; exp.X_op_symbol = fde->start_address; /* Code length. */ exp.X_add_number = 0; emit_expr (&exp, addr_size); augmentation_size = encoding_size (fde->lsda_encoding); if (eh_frame) out_uleb128 (augmentation_size); /* Augmentation size. */ emit_expr_encoded (&fde->lsda, cie->lsda_encoding, false); for (; first; first = first->next) if (CUR_SEG (first) == CUR_SEG (fde)) output_cfi_insn (first); frag_align (align, DW_CFA_nop, 0); symbol_set_value_now (end_address); } /* Allow these insns to be put in the initial sequence of a CIE. If J is non-NULL, then compare I and J insns for a match. */ static inline bool initial_cie_insn (const struct cfi_insn_data *i, const struct cfi_insn_data *j) { if (j && i->insn != j->insn) return false; switch (i->insn) { case DW_CFA_offset: case DW_CFA_def_cfa: case DW_CFA_val_offset: if (j) { if (i->u.ri.reg != j->u.ri.reg) return false; if (i->u.ri.offset != j->u.ri.offset) return false; } break; case DW_CFA_register: if (j) { if (i->u.rr.reg1 != j->u.rr.reg1) return false; if (i->u.rr.reg2 != j->u.rr.reg2) return false; } break; case DW_CFA_def_cfa_register: case DW_CFA_restore: case DW_CFA_undefined: case DW_CFA_same_value: if (j) { if (i->u.r != j->u.r) return false; } break; case DW_CFA_def_cfa_offset: if (j) { if (i->u.i != j->u.i) return false; } break; default: return false; } return true; } static struct cie_entry * select_cie_for_fde (struct fde_entry *fde, bool eh_frame, struct cfi_insn_data **pfirst, int align) { struct cfi_insn_data *i, *j; struct cie_entry *cie; for (cie = cie_root; cie; cie = cie->next) { if (CUR_SEG (cie) != CUR_SEG (fde)) continue; #ifdef tc_cie_fde_equivalent_extra if (!tc_cie_fde_equivalent_extra (cie, fde)) continue; #endif if (cie->return_column != fde->return_column || cie->signal_frame != fde->signal_frame || cie->per_encoding != fde->per_encoding || cie->lsda_encoding != fde->lsda_encoding) continue; if (cie->per_encoding != DW_EH_PE_omit) { if (cie->personality.X_op != fde->personality.X_op || (cie->personality.X_add_number != fde->personality.X_add_number)) continue; switch (cie->personality.X_op) { case O_constant: if (cie->personality.X_unsigned != fde->personality.X_unsigned) continue; break; case O_symbol: if (cie->personality.X_add_symbol != fde->personality.X_add_symbol) continue; break; default: abort (); } } for (i = cie->first, j = fde->data; i != cie->last && j != NULL; i = i->next, j = j->next) { if (!initial_cie_insn (i, j)) break; } if (i == cie->last) { *pfirst = j; return cie; } } cie = XNEW (struct cie_entry); cie->next = cie_root; cie_root = cie; SET_CUR_SEG (cie, CUR_SEG (fde)); cie->return_column = fde->return_column; cie->signal_frame = fde->signal_frame; cie->per_encoding = fde->per_encoding; cie->lsda_encoding = fde->lsda_encoding; cie->personality = fde->personality; cie->first = fde->data; #ifdef tc_cie_entry_init_extra tc_cie_entry_init_extra (cie, fde) #endif for (i = cie->first; i ; i = i->next) if (!initial_cie_insn (i, NULL)) break; cie->last = i; *pfirst = i; output_cie (cie, eh_frame, align); return cie; } #ifdef md_reg_eh_frame_to_debug_frame static void cfi_change_reg_numbers (struct cfi_insn_data *insn, segT ccseg) { for (; insn; insn = insn->next) { if (CUR_SEG (insn) != ccseg) continue; switch (insn->insn) { case DW_CFA_advance_loc: case DW_CFA_def_cfa_offset: case DW_CFA_remember_state: case DW_CFA_restore_state: case DW_CFA_GNU_window_save: case CFI_escape: case CFI_label: break; case DW_CFA_def_cfa: case DW_CFA_offset: insn->u.ri.reg = md_reg_eh_frame_to_debug_frame (insn->u.ri.reg); break; case DW_CFA_def_cfa_register: case DW_CFA_undefined: case DW_CFA_same_value: case DW_CFA_restore: insn->u.r = md_reg_eh_frame_to_debug_frame (insn->u.r); break; case DW_CFA_register: insn->u.rr.reg1 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg1); insn->u.rr.reg2 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg2); break; case CFI_val_encoded_addr: insn->u.ea.reg = md_reg_eh_frame_to_debug_frame (insn->u.ea.reg); break; default: abort (); } } } #else #define cfi_change_reg_numbers(insn, cseg) do { } while (0) #endif #if SUPPORT_COMPACT_EH static void cfi_emit_eh_header (symbolS *sym, bfd_vma addend) { expressionS exp; exp.X_add_number = addend; exp.X_add_symbol = sym; emit_expr_encoded (&exp, DW_EH_PE_sdata4 | DW_EH_PE_pcrel, false); } static void output_eh_header (struct fde_entry *fde) { char *p; bfd_vma addend; if (fde->eh_header_type == EH_COMPACT_INLINE) addend = 0; else addend = 1; cfi_emit_eh_header (fde->start_address, addend); if (fde->eh_header_type == EH_COMPACT_INLINE) { p = frag_more (4); /* Inline entries always use PR1. */ *(p++) = 1; memcpy(p, fde->eh_data, 3); } else { if (fde->eh_header_type == EH_COMPACT_LEGACY) addend = 1; else if (fde->eh_header_type == EH_COMPACT_OUTLINE || fde->eh_header_type == EH_COMPACT_OUTLINE_DONE) addend = 0; else abort (); cfi_emit_eh_header (fde->eh_loc, addend); } } #endif void cfi_finish (void) { struct cie_entry *cie, *cie_next; segT cfi_seg, ccseg; struct fde_entry *fde; struct cfi_insn_data *first; int save_flag_traditional_format, seek_next_seg; if (all_fde_data == 0) return; if ((all_cfi_sections & CFI_EMIT_eh_frame) != 0 || (all_cfi_sections & CFI_EMIT_eh_frame_compact) != 0) { /* Make sure check_eh_frame doesn't do anything with our output. */ save_flag_traditional_format = flag_traditional_format; flag_traditional_format = 1; if (!EH_FRAME_LINKONCE) { /* Open .eh_frame section. */ cfi_seg = get_cfi_seg (NULL, ".eh_frame", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), EH_FRAME_ALIGNMENT); #ifdef md_fix_up_eh_frame md_fix_up_eh_frame (cfi_seg); #else (void) cfi_seg; #endif } do { ccseg = NULL; seek_next_seg = 0; for (cie = cie_root; cie; cie = cie_next) { cie_next = cie->next; free ((void *) cie); } cie_root = NULL; for (fde = all_fde_data; fde ; fde = fde->next) { if ((fde->sections & CFI_EMIT_eh_frame) == 0 && (fde->sections & CFI_EMIT_eh_frame_compact) == 0) continue; #if SUPPORT_COMPACT_EH /* Emit a LEGACY format header if we have processed all of the .cfi directives without encountering either inline or out-of-line compact unwinding opcodes. */ if (fde->eh_header_type == EH_COMPACT_HAS_LSDA || fde->eh_header_type == EH_COMPACT_UNKNOWN) fde->eh_header_type = EH_COMPACT_LEGACY; if (fde->eh_header_type != EH_COMPACT_LEGACY) continue; #endif if (EH_FRAME_LINKONCE) { if (HANDLED (fde)) continue; if (seek_next_seg && CUR_SEG (fde) != ccseg) { seek_next_seg = 2; continue; } if (!seek_next_seg) { ccseg = CUR_SEG (fde); /* Open .eh_frame section. */ cfi_seg = get_cfi_seg (ccseg, ".eh_frame", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), EH_FRAME_ALIGNMENT); #ifdef md_fix_up_eh_frame md_fix_up_eh_frame (cfi_seg); #else (void) cfi_seg; #endif seek_next_seg = 1; } SET_HANDLED (fde, 1); } if (fde->end_address == NULL) { as_bad (_("open CFI at the end of file; " "missing .cfi_endproc directive")); fde->end_address = fde->start_address; } cie = select_cie_for_fde (fde, true, &first, 2); fde->eh_loc = symbol_temp_new_now (); output_fde (fde, cie, true, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2); } } while (EH_FRAME_LINKONCE && seek_next_seg == 2); if (EH_FRAME_LINKONCE) for (fde = all_fde_data; fde ; fde = fde->next) SET_HANDLED (fde, 0); #if SUPPORT_COMPACT_EH if (compact_eh) { /* Create remaining out of line table entries. */ do { ccseg = NULL; seek_next_seg = 0; for (fde = all_fde_data; fde ; fde = fde->next) { if ((fde->sections & CFI_EMIT_eh_frame) == 0 && (fde->sections & CFI_EMIT_eh_frame_compact) == 0) continue; if (fde->eh_header_type != EH_COMPACT_OUTLINE) continue; if (HANDLED (fde)) continue; if (seek_next_seg && CUR_SEG (fde) != ccseg) { seek_next_seg = 2; continue; } if (!seek_next_seg) { ccseg = CUR_SEG (fde); /* Open .gnu_extab section. */ get_cfi_seg (ccseg, ".gnu_extab", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), 1); seek_next_seg = 1; } SET_HANDLED (fde, 1); frag_align (1, 0, 0); record_alignment (now_seg, 1); output_compact_unwind_data (fde, 1); } } while (EH_FRAME_LINKONCE && seek_next_seg == 2); for (fde = all_fde_data; fde ; fde = fde->next) SET_HANDLED (fde, 0); /* Create index table fragments. */ do { ccseg = NULL; seek_next_seg = 0; for (fde = all_fde_data; fde ; fde = fde->next) { if ((fde->sections & CFI_EMIT_eh_frame) == 0 && (fde->sections & CFI_EMIT_eh_frame_compact) == 0) continue; if (HANDLED (fde)) continue; if (seek_next_seg && CUR_SEG (fde) != ccseg) { seek_next_seg = 2; continue; } if (!seek_next_seg) { ccseg = CUR_SEG (fde); /* Open .eh_frame_entry section. */ cfi_seg = get_cfi_seg (ccseg, ".eh_frame_entry", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), 2); seek_next_seg = 1; } SET_HANDLED (fde, 1); output_eh_header (fde); } } while (seek_next_seg == 2); for (fde = all_fde_data; fde ; fde = fde->next) SET_HANDLED (fde, 0); } #endif /* SUPPORT_COMPACT_EH */ flag_traditional_format = save_flag_traditional_format; } /* Generate SFrame section if the user specifies: - the command line option to gas, or - .sframe in the .cfi_sections directive. */ if (flag_gen_sframe || (all_cfi_sections & CFI_EMIT_sframe) != 0) { if (support_sframe_p () && !SUPPORT_FRAME_LINKONCE) { segT sframe_seg; int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1; sframe_seg = get_cfi_seg (NULL, ".sframe", (SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY), alignment); output_sframe (sframe_seg); } else as_bad (_(".sframe not supported for target")); } if ((all_cfi_sections & CFI_EMIT_debug_frame) != 0) { int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1; if (!SUPPORT_FRAME_LINKONCE) get_cfi_seg (NULL, ".debug_frame", SEC_READONLY | SEC_DEBUGGING, alignment); do { ccseg = NULL; seek_next_seg = 0; for (cie = cie_root; cie; cie = cie_next) { cie_next = cie->next; free ((void *) cie); } cie_root = NULL; for (fde = all_fde_data; fde ; fde = fde->next) { if ((fde->sections & CFI_EMIT_debug_frame) == 0) continue; if (SUPPORT_FRAME_LINKONCE) { if (HANDLED (fde)) continue; if (seek_next_seg && CUR_SEG (fde) != ccseg) { seek_next_seg = 2; continue; } if (!seek_next_seg) { ccseg = CUR_SEG (fde); /* Open .debug_frame section. */ get_cfi_seg (ccseg, ".debug_frame", SEC_READONLY | SEC_DEBUGGING, alignment); seek_next_seg = 1; } SET_HANDLED (fde, 1); } if (fde->end_address == NULL) { as_bad (_("open CFI at the end of file; " "missing .cfi_endproc directive")); fde->end_address = fde->start_address; } fde->per_encoding = DW_EH_PE_omit; fde->lsda_encoding = DW_EH_PE_omit; cfi_change_reg_numbers (fde->data, ccseg); cie = select_cie_for_fde (fde, false, &first, alignment); output_fde (fde, cie, false, first, alignment); } } while (SUPPORT_FRAME_LINKONCE && seek_next_seg == 2); if (SUPPORT_FRAME_LINKONCE) for (fde = all_fde_data; fde ; fde = fde->next) SET_HANDLED (fde, 0); } if (dwcfi_hash) htab_delete (dwcfi_hash); } #else /* TARGET_USE_CFIPOP */ /* Emit an intelligible error message for missing support. */ static void dot_cfi_dummy (int ignored ATTRIBUTE_UNUSED) { as_bad (_("CFI is not supported for this target")); ignore_rest_of_line (); } const pseudo_typeS cfi_pseudo_table[] = { { "cfi_sections", dot_cfi_dummy, 0 }, { "cfi_startproc", dot_cfi_dummy, 0 }, { "cfi_endproc", dot_cfi_dummy, 0 }, { "cfi_fde_data", dot_cfi_dummy, 0 }, { "cfi_def_cfa", dot_cfi_dummy, 0 }, { "cfi_def_cfa_register", dot_cfi_dummy, 0 }, { "cfi_def_cfa_offset", dot_cfi_dummy, 0 }, { "cfi_adjust_cfa_offset", dot_cfi_dummy, 0 }, { "cfi_offset", dot_cfi_dummy, 0 }, { "cfi_rel_offset", dot_cfi_dummy, 0 }, { "cfi_register", dot_cfi_dummy, 0 }, { "cfi_return_column", dot_cfi_dummy, 0 }, { "cfi_restore", dot_cfi_dummy, 0 }, { "cfi_undefined", dot_cfi_dummy, 0 }, { "cfi_same_value", dot_cfi_dummy, 0 }, { "cfi_remember_state", dot_cfi_dummy, 0 }, { "cfi_restore_state", dot_cfi_dummy, 0 }, { "cfi_window_save", dot_cfi_dummy, 0 }, { "cfi_escape", dot_cfi_dummy, 0 }, { "cfi_signal_frame", dot_cfi_dummy, 0 }, { "cfi_personality", dot_cfi_dummy, 0 }, { "cfi_personality_id", dot_cfi_dummy, 0 }, { "cfi_lsda", dot_cfi_dummy, 0 }, { "cfi_val_encoded_addr", dot_cfi_dummy, 0 }, { "cfi_label", dot_cfi_dummy, 0 }, { "cfi_inline_lsda", dot_cfi_dummy, 0 }, { "cfi_val_offset", dot_cfi_dummy, 0 }, { NULL, NULL, 0 } }; void cfi_finish (void) { } #endif /* TARGET_USE_CFIPOP */