X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gas%2Fdwarf2dbg.c;h=2fa6d51cb0ba7a02a5f952a99fca1cf380842020;hb=aac129d77611fab3db3f354c67c0f2c9406fa828;hp=4061c72893fff7140ef1a45774d12b4b5595e376;hpb=91d6fa6a035cc7d0b7be5c99c194a64cb80924b0;p=deliverable%2Fbinutils-gdb.git diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c index 4061c72893..2fa6d51cb0 100644 --- a/gas/dwarf2dbg.c +++ b/gas/dwarf2dbg.c @@ -89,6 +89,20 @@ #define DWARF2_FILE_SIZE_NAME(FILENAME,DIRNAME) 0 #endif +#ifndef DWARF2_VERSION +#define DWARF2_VERSION 2 +#endif + +/* The .debug_aranges version has been 2 in DWARF version 2, 3 and 4. */ +#ifndef DWARF2_ARANGES_VERSION +#define DWARF2_ARANGES_VERSION 2 +#endif + +/* This implementation output version 2 .debug_line information. */ +#ifndef DWARF2_LINE_VERSION +#define DWARF2_LINE_VERSION 2 +#endif + #include "subsegs.h" #include "dwarf2.h" @@ -105,7 +119,7 @@ opcodes and variable-length operands cannot be used. If this macro is nonzero, use the DW_LNS_fixed_advance_pc opcode instead. */ #ifndef DWARF2_USE_FIXED_ADVANCE_PC -# define DWARF2_USE_FIXED_ADVANCE_PC 0 +# define DWARF2_USE_FIXED_ADVANCE_PC linkrelax #endif /* First special line opcde - leave room for the standard opcodes. @@ -203,6 +217,10 @@ static struct dwarf2_line_info current = { 0 }; +/* Lines that are at the same location as CURRENT, and which are waiting + for a label. */ +static struct line_entry *pending_lines, **pending_lines_tail = &pending_lines; + /* The size of an address on the target. */ static unsigned int sizeof_address; @@ -276,22 +294,47 @@ get_line_subseg (segT seg, subsegT subseg) return lss; } -/* Record an entry for LOC occurring at LABEL. */ +/* Push LOC onto the pending lines list. */ static void -dwarf2_gen_line_info_1 (symbolS *label, struct dwarf2_line_info *loc) +dwarf2_push_line (struct dwarf2_line_info *loc) { - struct line_subseg *lss; struct line_entry *e; e = (struct line_entry *) xmalloc (sizeof (*e)); e->next = NULL; - e->label = label; + e->label = NULL; e->loc = *loc; - lss = get_line_subseg (now_seg, now_subseg); - *lss->ptail = e; - lss->ptail = &e->next; + *pending_lines_tail = e; + pending_lines_tail = &(*pending_lines_tail)->next; +} + +/* Emit all pending line information. LABEL is the label with which the + lines should be associated, or null if they should be associated with + the current position. */ + +static void +dwarf2_flush_pending_lines (symbolS *label) +{ + if (pending_lines) + { + struct line_subseg *lss; + struct line_entry *e; + + if (!label) + label = symbol_temp_new_now (); + + for (e = pending_lines; e; e = e->next) + e->label = label; + + lss = get_line_subseg (now_seg, now_subseg); + *lss->ptail = pending_lines; + lss->ptail = pending_lines_tail; + + pending_lines = NULL; + pending_lines_tail = &pending_lines; + } } /* Record an entry for LOC occurring at OFS within the current fragment. */ @@ -302,8 +345,6 @@ dwarf2_gen_line_info (addressT ofs, struct dwarf2_line_info *loc) static unsigned int line = -1; static unsigned int filenum = -1; - symbolS *sym; - /* Early out for as-yet incomplete location information. */ if (loc->filenum == 0 || loc->line == 0) return; @@ -319,8 +360,18 @@ dwarf2_gen_line_info (addressT ofs, struct dwarf2_line_info *loc) line = loc->line; filenum = loc->filenum; - sym = symbol_temp_new (now_seg, ofs, frag_now); - dwarf2_gen_line_info_1 (sym, loc); + dwarf2_push_line (loc); + if (linkrelax) + { + char name[120]; + + /* Use a non-fake name for the line number location, + so that it can be referred to by relocations. */ + sprintf (name, ".Loc.%u.%u", line, filenum); + dwarf2_flush_pending_lines (symbol_new (name, now_seg, ofs, frag_now)); + } + else + dwarf2_flush_pending_lines (symbol_temp_new (now_seg, ofs, frag_now)); } /* Returns the current source information. If .file directives have @@ -381,6 +432,11 @@ dwarf2_emit_insn (int size) void dwarf2_consume_line_info (void) { + /* If the consumer has stashed the current location away for later use, + assume that any earlier location information should be associated + with ".". */ + dwarf2_flush_pending_lines (NULL); + /* Unless we generate DWARF2 debugging information for each assembler line, we only emit one line symbol for one LOC. */ dwarf2_loc_directive_seen = FALSE; @@ -412,7 +468,8 @@ dwarf2_emit_label (symbolS *label) loc.flags |= DWARF2_FLAG_BASIC_BLOCK; - dwarf2_gen_line_info_1 (label, &loc); + dwarf2_push_line (&loc); + dwarf2_flush_pending_lines (label); dwarf2_consume_line_info (); } @@ -431,14 +488,14 @@ get_filenum (const char *filename, unsigned int num) if (num == 0 && last_used) { if (! files[last_used].dir - && strcmp (filename, files[last_used].filename) == 0) + && filename_cmp (filename, files[last_used].filename) == 0) return last_used; if (files[last_used].dir - && strncmp (filename, dirs[files[last_used].dir], - last_used_dir_len) == 0 + && filename_ncmp (filename, dirs[files[last_used].dir], + last_used_dir_len) == 0 && IS_DIR_SEPARATOR (filename [last_used_dir_len]) - && strcmp (filename + last_used_dir_len + 1, - files[last_used].filename) == 0) + && filename_cmp (filename + last_used_dir_len + 1, + files[last_used].filename) == 0) return last_used; } @@ -460,7 +517,7 @@ get_filenum (const char *filename, unsigned int num) --dir_len; #endif for (dir = 1; dir < dirs_in_use; ++dir) - if (strncmp (filename, dirs[dir], dir_len) == 0 + if (filename_ncmp (filename, dirs[dir], dir_len) == 0 && dirs[dir][dir_len] == '\0') break; @@ -485,7 +542,7 @@ get_filenum (const char *filename, unsigned int num) for (i = 1; i < files_in_use; ++i) if (files[i].dir == dir && files[i].filename - && strcmp (file, files[i].filename) == 0) + && filename_cmp (file, files[i].filename) == 0) { last_used = i; last_used_dir_len = dir_len; @@ -572,7 +629,7 @@ dwarf2_directive_loc (int dummy ATTRIBUTE_UNUSED) /* If we see two .loc directives in a row, force the first one to be output now. */ if (dwarf2_loc_directive_seen) - dwarf2_emit_insn (0); + dwarf2_push_line (¤t); filenum = get_absolute_expression (); SKIP_WHITESPACE (); @@ -825,24 +882,22 @@ out_set_addr (symbolS *sym) emit_expr (&exp, sizeof_address); } -#if DWARF2_LINE_MIN_INSN_LENGTH > 1 static void scale_addr_delta (addressT *); static void scale_addr_delta (addressT *addr_delta) { static int printed_this = 0; - if (*addr_delta % DWARF2_LINE_MIN_INSN_LENGTH != 0) + if (DWARF2_LINE_MIN_INSN_LENGTH > 1) { - if (!printed_this) - as_bad("unaligned opcodes detected in executable segment"); - printed_this = 1; + if (*addr_delta % DWARF2_LINE_MIN_INSN_LENGTH != 0 && !printed_this) + { + as_bad("unaligned opcodes detected in executable segment"); + printed_this = 1; + } + *addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH; } - *addr_delta /= DWARF2_LINE_MIN_INSN_LENGTH; } -#else -#define scale_addr_delta(A) -#endif /* Encode a pair of line and address skips as efficiently as possible. Note that the line skip is signed, whereas the address skip is unsigned. @@ -1017,6 +1072,7 @@ out_inc_line_addr (int line_delta, addressT addr_delta) line and address information, but it is required if linker relaxation could change the code offsets. The following two routines *must* be kept in sync. */ +#define ADDR_DELTA_LIMIT 50000 static int size_fixed_inc_line_addr (int line_delta, addressT addr_delta) @@ -1027,7 +1083,7 @@ size_fixed_inc_line_addr (int line_delta, addressT addr_delta) if (line_delta != INT_MAX) len = 1 + sizeof_leb128 (line_delta, 1); - if (addr_delta > 50000) + if (addr_delta > ADDR_DELTA_LIMIT) { /* DW_LNS_extended_op */ len += 1 + sizeof_leb128 (sizeof_address + 1, 0); @@ -1075,12 +1131,12 @@ emit_fixed_inc_line_addr (int line_delta, addressT addr_delta, fragS *frag, which this function would not be used) could change the operand by an unknown amount. If the address increment is getting close to the limit, just reset the address. */ - if (addr_delta > 50000) + if (addr_delta > ADDR_DELTA_LIMIT) { symbolS *to_sym; expressionS exp; - gas_assert (pexp->X_op = O_subtract); + gas_assert (pexp->X_op == O_subtract); to_sym = pexp->X_add_symbol; *p++ = DW_LNS_extended_op; @@ -1184,7 +1240,24 @@ dwarf2dbg_convert_frag (fragS *frag) { offsetT addr_diff; - addr_diff = resolve_symbol_value (frag->fr_symbol); + if (DWARF2_USE_FIXED_ADVANCE_PC) + { + /* If linker relaxation is enabled then the distance bewteen the two + symbols in the frag->fr_symbol expression might change. Hence we + cannot rely upon the value computed by resolve_symbol_value. + Instead we leave the expression unfinalized and allow + emit_fixed_inc_line_addr to create a fixup (which later becomes a + relocation) that will allow the linker to correctly compute the + actual address difference. We have to use a fixed line advance for + this as we cannot (easily) relocate leb128 encoded values. */ + int saved_finalize_syms = finalize_syms; + + finalize_syms = 0; + addr_diff = resolve_symbol_value (frag->fr_symbol); + finalize_syms = saved_finalize_syms; + } + else + addr_diff = resolve_symbol_value (frag->fr_symbol); /* fr_var carries the max_chars that we created the fragment with. fr_subtype carries the current expected length. We must, of @@ -1420,7 +1493,7 @@ out_debug_line (segT line_seg) line_end = exp.X_add_symbol; /* Version. */ - out_two (2); + out_two (DWARF2_LINE_VERSION); /* Length of the prologue following this length. */ prologue_end = symbol_temp_make (); @@ -1455,7 +1528,11 @@ out_debug_line (segT line_seg) /* For each section, emit a statement program. */ for (s = all_segs; s; s = s->next) - process_entries (s->seg, s->head->head); + if (SEG_NORMAL (s->seg)) + process_entries (s->seg, s->head->head); + else + as_warn ("dwarf line number information for %s ignored", + segment_name (s->seg)); symbol_set_value_now (line_end); } @@ -1524,7 +1601,7 @@ out_debug_aranges (segT aranges_seg, segT info_seg) aranges_end = exp.X_add_symbol; /* Version. */ - out_two (2); + out_two (DWARF2_ARANGES_VERSION); /* Offset to .debug_info. */ TC_DWARF2_EMIT_OFFSET (section_symbol (info_seg), sizeof_offset); @@ -1590,7 +1667,11 @@ out_debug_abbrev (segT abbrev_seg, if (all_segs->next == NULL) { out_abbrev (DW_AT_low_pc, DW_FORM_addr); - out_abbrev (DW_AT_high_pc, DW_FORM_addr); + if (DWARF2_VERSION < 4) + out_abbrev (DW_AT_high_pc, DW_FORM_addr); + else + out_abbrev (DW_AT_high_pc, (sizeof_address == 4 + ? DW_FORM_data4 : DW_FORM_data8)); } else { @@ -1627,7 +1708,7 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg) info_end = exp.X_add_symbol; /* DWARF version. */ - out_two (2); + out_two (DWARF2_VERSION); /* .debug_abbrev offset */ TC_DWARF2_EMIT_OFFSET (section_symbol (abbrev_seg), sizeof_offset); @@ -1653,7 +1734,13 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg) emit_expr (&exp, sizeof_address); /* DW_AT_high_pc */ - exp.X_op = O_symbol; + if (DWARF2_VERSION < 4) + exp.X_op = O_symbol; + else + { + exp.X_op = O_subtract; + exp.X_op_symbol = all_segs->text_start; + } exp.X_add_symbol = all_segs->text_end; exp.X_add_number = 0; emit_expr (&exp, sizeof_address); @@ -1718,11 +1805,12 @@ dwarf2_init (void) /* Finish the dwarf2 debug sections. We emit .debug.line if there were any .file/.loc directives, or --gdwarf2 was given, or if the - file has a non-empty .debug_info section. If we emit .debug_line, - and the .debug_info section is empty, we also emit .debug_info, - .debug_aranges and .debug_abbrev. ALL_SEGS will be non-null if - there were any .file/.loc directives, or --gdwarf2 was given and - there were any located instructions emitted. */ + file has a non-empty .debug_info section and an empty .debug_line + section. If we emit .debug_line, and the .debug_info section is + empty, we also emit .debug_info, .debug_aranges and .debug_abbrev. + ALL_SEGS will be non-null if there were any .file/.loc directives, + or --gdwarf2 was given and there were any located instructions + emitted. */ void dwarf2_finish (void) @@ -1731,13 +1819,24 @@ dwarf2_finish (void) struct line_seg *s; segT info_seg; int emit_other_sections = 0; + int empty_debug_line = 0; info_seg = bfd_get_section_by_name (stdoutput, ".debug_info"); emit_other_sections = info_seg == NULL || !seg_not_empty_p (info_seg); - if (!all_segs && emit_other_sections) - /* There is no line information and no non-empty .debug_info - section. */ + line_seg = bfd_get_section_by_name (stdoutput, ".debug_line"); + empty_debug_line = line_seg == NULL || !seg_not_empty_p (line_seg); + + /* We can't construct a new debug_line section if we already have one. + Give an error. */ + if (all_segs && !empty_debug_line) + as_fatal ("duplicate .debug_line sections"); + + if ((!all_segs && emit_other_sections) + || (!emit_other_sections && !empty_debug_line)) + /* If there is no line information and no non-empty .debug_info + section, or if there is both a non-empty .debug_info and a non-empty + .debug_line, then we do nothing. */ return; /* Calculate the size of an address for the target machine. */