From: Ali Tamur Date: Tue, 27 Aug 2019 02:22:09 +0000 (-0700) Subject: DWARF 5 support: Handle line table and file indexes X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7ba99d2188454b9e08bdbf3616773a16ad9c9f95;p=binutils-gdb.git DWARF 5 support: Handle line table and file indexes * Fix handling of file and directory indexes in line tables; in DWARF 5 the indexes are zero-based. Make file_names field private to abstract this detail from the clients. Introduce file_names, is_valid_file_index and file_names_size methods. Reflect these changes in clients. * Handle DW_FORM_data16 in read_formatted_entries; it is used to record MD5 of the file entries in DWARF 5. * Fix a bug in line header parsing that calculates the length of the header incorrectly. (Seemingly this manifests itself only in DWARF 5). Tested with CC=/usr/bin/gcc (version 8.3.0) against master branch (also with -gsplit-dwarf and -gdwarf-4 flags) and there was no increase in the set of tests that fails. (gdb still cannot debug a 'hello world' program with DWARF 5, so for the time being, this is all we care about). This is part of an effort to support DWARF 5 in gdb. gdb/ChangeLog: * dwarf2read.c (dir_index): Change type. (file_name_index): Likewise. (line_header::include_dir_at): Change comment and implementation on whether it is DWARF 5. (line_header::is_valid_file_index): New function. (line_header::file_name_at): Change comment and implementation on whether it is DWARF 5. (line_header::file_names): Change to private field renamed as m_file_names and introduce a new accessor method. (line_header::file_names_size): New method. (line_header::include_dirs): Change to private field and rename as m_include_dirs. (dw2_get_file_names_reader): Define local var at a smaller scope and reflect API change. (dwarf2_cu::setup_type_unit_groups): Reflect API change. (process_structure_scope): Likewise. (line_header::add_include_dir): Change message and reflect renaming. (line_header::add_file_name): Likewise. (read_formatted_entries): Handle DW_FORM_data16. (dwarf_decode_line_header): Fix line header length calculation. (psymtab_include_file_name): Change comment and API. (lnp_state_machine::m_file): Update comment and reflect type change. (lnp_state_machine::record_line): Reflect type change. (dwarf_decode_lines): Reflect API change. (file_file_name): Likewise. (file_full_name): Likewise. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 41ee329fc15..a70f3e1795c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,32 @@ +2019-10-21 Ali Tamur + + * dwarf2read.c (dir_index): Change type. + (file_name_index): Likewise. + (line_header::include_dir_at): Change comment and implementation on + whether it is DWARF 5. + (line_header::is_valid_file_index): New function. + (line_header::file_name_at): Change comment and implementation on + whether it is DWARF 5. + (line_header::file_names): Change to private field renamed as + m_file_names and introduce a new accessor method. + (line_header::file_names_size): New method. + (line_header::include_dirs): Change to private field and rename as + m_include_dirs. + (dw2_get_file_names_reader): Define local var at a smaller scope and + reflect API change. + (dwarf2_cu::setup_type_unit_groups): Reflect API change. + (process_structure_scope): Likewise. + (line_header::add_include_dir): Change message and reflect renaming. + (line_header::add_file_name): Likewise. + (read_formatted_entries): Handle DW_FORM_data16. + (dwarf_decode_line_header): Fix line header length calculation. + (psymtab_include_file_name): Change comment and API. + (lnp_state_machine::m_file): Update comment and reflect type change. + (lnp_state_machine::record_line): Reflect type change. + (dwarf_decode_lines): Reflect API change. + (file_file_name): Likewise. + (file_full_name): Likewise. + 2019-10-21 Andrew Burgess * objfiles.c (sort_cmp): Ensure that !(a < a) holds true. diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index 3a88c45af0c..4372a47c6d6 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -909,13 +909,13 @@ typedef void (die_reader_func_ftype) (const struct die_reader_specs *reader, int has_children, void *data); -/* A 1-based directory index. This is a strong typedef to prevent - accidentally using a directory index as a 0-based index into an - array/vector. */ -enum class dir_index : unsigned int {}; +/* dir_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 and + later. */ +typedef int dir_index; -/* Likewise, a 1-based file name index. */ -enum class file_name_index : unsigned int {}; +/* file_name_index is 1-based in DWARF 4 and before, and is 0-based in DWARF 5 + and later. */ +typedef int file_name_index; struct file_entry { @@ -967,32 +967,47 @@ struct line_header void add_file_name (const char *name, dir_index d_index, unsigned int mod_time, unsigned int length); - /* Return the include dir at INDEX (1-based). Returns NULL if INDEX - is out of bounds. */ + /* Return the include dir at INDEX (0-based in DWARF 5 and 1-based before). + Returns NULL if INDEX is out of bounds. */ const char *include_dir_at (dir_index index) const { - /* Convert directory index number (1-based) to vector index - (0-based). */ - size_t vec_index = to_underlying (index) - 1; - - if (vec_index >= include_dirs.size ()) + int vec_index; + if (version >= 5) + vec_index = index; + else + vec_index = index - 1; + if (vec_index < 0 || vec_index >= m_include_dirs.size ()) return NULL; - return include_dirs[vec_index]; + return m_include_dirs[vec_index]; } - /* Return the file name at INDEX (1-based). Returns NULL if INDEX - is out of bounds. */ - file_entry *file_name_at (file_name_index index) + bool is_valid_file_index (int file_index) { - /* Convert file name index number (1-based) to vector index - (0-based). */ - size_t vec_index = to_underlying (index) - 1; + if (version >= 5) + return 0 <= file_index && file_index < file_names_size (); + return 1 <= file_index && file_index <= file_names_size (); + } - if (vec_index >= file_names.size ()) + /* Return the file name at INDEX (0-based in DWARF 5 and 1-based before). + Returns NULL if INDEX is out of bounds. */ + file_entry *file_name_at (file_name_index index) + { + int vec_index; + if (version >= 5) + vec_index = index; + else + vec_index = index - 1; + if (vec_index < 0 || vec_index >= m_file_names.size ()) return NULL; - return &file_names[vec_index]; + return &m_file_names[vec_index]; } + /* The indexes are 0-based in DWARF 5 and 1-based in DWARF 4. Therefore, + this method should only be used to iterate through all file entries in an + index-agnostic manner. */ + std::vector &file_names () + { return m_file_names; } + /* Offset of line number information in .debug_line section. */ sect_offset sect_off {}; @@ -1015,16 +1030,23 @@ struct line_header element is standard_opcode_lengths[opcode_base - 1]. */ std::unique_ptr standard_opcode_lengths; - /* The include_directories table. Note these are observing - pointers. The memory is owned by debug_line_buffer. */ - std::vector include_dirs; - - /* The file_names table. */ - std::vector file_names; + int file_names_size () + { return m_file_names.size(); } /* The start and end of the statement program following this header. These point into dwarf2_per_objfile->line_buffer. */ const gdb_byte *statement_program_start {}, *statement_program_end {}; + + private: + /* The include_directories table. Note these are observing + pointers. The memory is owned by debug_line_buffer. */ + std::vector m_include_dirs; + + /* The file_names table. This is private because the meaning of indexes + differs among DWARF versions (The first valid index is 1 in DWARF 4 and + before, and is 0 in DWARF 5 and later). So the client should use + file_name_at method for access. */ + std::vector m_file_names; }; typedef std::unique_ptr line_header_up; @@ -3640,7 +3662,6 @@ dw2_get_file_names_reader (const struct die_reader_specs *reader, struct objfile *objfile = dwarf2_per_objfile->objfile; struct dwarf2_per_cu_data *lh_cu; struct attribute *attr; - int i; void **slot; struct quick_file_names *qfn; @@ -3699,12 +3720,12 @@ dw2_get_file_names_reader (const struct die_reader_specs *reader, if (strcmp (fnd.name, "") != 0) ++offset; - qfn->num_file_names = offset + lh->file_names.size (); + qfn->num_file_names = offset + lh->file_names_size (); qfn->file_names = XOBNEWVEC (&objfile->objfile_obstack, const char *, qfn->num_file_names); if (offset != 0) qfn->file_names[0] = xstrdup (fnd.name); - for (i = 0; i < lh->file_names.size (); ++i) + for (int i = 0; i < lh->file_names_size (); ++i) qfn->file_names[i + offset] = file_full_name (i + 1, lh.get (), fnd.comp_dir); qfn->real_names = NULL; @@ -11702,14 +11723,14 @@ dwarf2_cu::setup_type_unit_groups (struct die_info *die) process_full_type_unit still needs to know if this is the first time. */ - tu_group->num_symtabs = line_header->file_names.size (); + tu_group->num_symtabs = line_header->file_names_size (); tu_group->symtabs = XNEWVEC (struct symtab *, - line_header->file_names.size ()); + line_header->file_names_size ()); - for (i = 0; i < line_header->file_names.size (); ++i) + auto &file_names = line_header->file_names (); + for (i = 0; i < file_names.size (); ++i) { - file_entry &fe = line_header->file_names[i]; - + file_entry &fe = file_names[i]; dwarf2_start_subfile (this, fe.name, fe.include_dir (line_header)); buildsym_compunit *b = get_builder (); @@ -11738,10 +11759,10 @@ dwarf2_cu::setup_type_unit_groups (struct die_info *die) compunit_language (cust), 0, cust)); - for (i = 0; i < line_header->file_names.size (); ++i) + auto &file_names = line_header->file_names (); + for (i = 0; i < file_names.size (); ++i) { - file_entry &fe = line_header->file_names[i]; - + file_entry &fe = file_names[i]; fe.symtab = tu_group->symtabs[i]; } } @@ -16215,7 +16236,7 @@ process_structure_scope (struct die_info *die, struct dwarf2_cu *cu) { /* Any related symtab will do. */ symtab - = cu->line_header->file_name_at (file_name_index (1))->symtab; + = cu->line_header->file_names ()[0].symtab; } else { @@ -20270,10 +20291,16 @@ void line_header::add_include_dir (const char *include_dir) { if (dwarf_line_debug >= 2) - fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n", - include_dirs.size () + 1, include_dir); - - include_dirs.push_back (include_dir); + { + size_t new_size; + if (version >= 5) + new_size = m_include_dirs.size (); + else + new_size = m_include_dirs.size () + 1; + fprintf_unfiltered (gdb_stdlog, "Adding dir %zu: %s\n", + new_size, include_dir); + } + m_include_dirs.push_back (include_dir); } void @@ -20283,10 +20310,16 @@ line_header::add_file_name (const char *name, unsigned int length) { if (dwarf_line_debug >= 2) - fprintf_unfiltered (gdb_stdlog, "Adding file %u: %s\n", - (unsigned) file_names.size () + 1, name); - - file_names.emplace_back (name, d_index, mod_time, length); + { + size_t new_size; + if (version >= 5) + new_size = file_names_size (); + else + new_size = file_names_size () + 1; + fprintf_unfiltered (gdb_stdlog, "Adding file %zu: %s\n", + new_size, name); + } + m_file_names.emplace_back (name, d_index, mod_time, length); } /* A convenience function to find the proper .debug_line section for a CU. */ @@ -20400,6 +20433,11 @@ read_formatted_entries (struct dwarf2_per_objfile *dwarf2_per_objfile, buf += 8; break; + case DW_FORM_data16: + /* This is used for MD5, but file_entry does not record MD5s. */ + buf += 16; + break; + case DW_FORM_udata: uint.emplace (read_unsigned_leb128 (abfd, buf, &bytes_read)); buf += bytes_read; @@ -20500,12 +20538,15 @@ dwarf_decode_line_header (sect_offset sect_off, struct dwarf2_cu *cu) read_checked_initial_length_and_offset (abfd, line_ptr, &cu->header, &bytes_read, &offset_size); line_ptr += bytes_read; + + const gdb_byte *start_here = line_ptr; + if (line_ptr + lh->total_length > (section->buffer + section->size)) { dwarf2_statement_list_fits_in_line_number_section_complaint (); return 0; } - lh->statement_program_end = line_ptr + lh->total_length; + lh->statement_program_end = start_here + lh->total_length; lh->version = read_2_bytes (abfd, line_ptr); line_ptr += 2; if (lh->version > 5) @@ -20535,6 +20576,7 @@ dwarf_decode_line_header (sect_offset sect_off, struct dwarf2_cu *cu) } lh->header_length = read_offset_1 (abfd, line_ptr, offset_size); line_ptr += offset_size; + lh->statement_program_start = line_ptr + lh->header_length; lh->minimum_instruction_length = read_1_byte (abfd, line_ptr); line_ptr += 1; if (lh->version >= 4) @@ -20619,7 +20661,6 @@ dwarf_decode_line_header (sect_offset sect_off, struct dwarf2_cu *cu) } line_ptr += bytes_read; } - lh->statement_program_start = line_ptr; if (line_ptr > (section->buffer + section->size)) complaint (_("line number info header doesn't " @@ -20629,19 +20670,17 @@ dwarf_decode_line_header (sect_offset sect_off, struct dwarf2_cu *cu) } /* Subroutine of dwarf_decode_lines to simplify it. - Return the file name of the psymtab for included file FILE_INDEX - in line header LH of PST. + Return the file name of the psymtab for the given file_entry. COMP_DIR is the compilation directory (DW_AT_comp_dir) or NULL if unknown. If space for the result is malloc'd, *NAME_HOLDER will be set. Returns NULL if FILE_INDEX should be ignored, i.e., it is pst->filename. */ static const char * -psymtab_include_file_name (const struct line_header *lh, int file_index, +psymtab_include_file_name (const struct line_header *lh, const file_entry &fe, const struct partial_symtab *pst, const char *comp_dir, gdb::unique_xmalloc_ptr *name_holder) { - const file_entry &fe = lh->file_names[file_index]; const char *include_name = fe.name; const char *include_name_to_compare = include_name; const char *pst_filename; @@ -20816,8 +20855,8 @@ private: and initialized according to the DWARF spec. */ unsigned char m_op_index = 0; - /* The line table index (1-based) of the current file. */ - file_name_index m_file = (file_name_index) 1; + /* The line table index of the current file. */ + file_name_index m_file = 1; unsigned int m_line = 1; /* These are initialized in the constructor. */ @@ -21009,7 +21048,7 @@ lnp_state_machine::record_line (bool end_sequence) fprintf_unfiltered (gdb_stdlog, "Processing actual line %u: file %u," " address %s, is_stmt %u, discrim %u\n", - m_line, to_underlying (m_file), + m_line, m_file, paddress (m_gdbarch, m_address), m_is_stmt, m_discriminator); } @@ -21348,17 +21387,15 @@ dwarf_decode_lines (struct line_header *lh, const char *comp_dir, if (decode_for_pst_p) { - int file_index; - /* Now that we're done scanning the Line Header Program, we can create the psymtab of each included file. */ - for (file_index = 0; file_index < lh->file_names.size (); file_index++) - if (lh->file_names[file_index].included_p == 1) + for (auto &file_entry : lh->file_names ()) + if (file_entry.included_p == 1) { gdb::unique_xmalloc_ptr name_holder; const char *include_name = - psymtab_include_file_name (lh, file_index, pst, comp_dir, - &name_holder); + psymtab_include_file_name (lh, file_entry, pst, + comp_dir, &name_holder); if (include_name != NULL) dwarf2_create_include_psymtab (include_name, pst, objfile); } @@ -21370,14 +21407,10 @@ dwarf_decode_lines (struct line_header *lh, const char *comp_dir, line numbers). */ buildsym_compunit *builder = cu->get_builder (); struct compunit_symtab *cust = builder->get_compunit_symtab (); - int i; - for (i = 0; i < lh->file_names.size (); i++) + for (auto &fe : lh->file_names ()) { - file_entry &fe = lh->file_names[i]; - dwarf2_start_subfile (cu, fe.name, fe.include_dir (lh)); - if (builder->get_current_subfile ()->symtab == NULL) { builder->get_current_subfile ()->symtab @@ -24182,17 +24215,17 @@ file_file_name (int file, struct line_header *lh) { /* Is the file number a valid index into the line header's file name table? Remember that file numbers start with one, not zero. */ - if (1 <= file && file <= lh->file_names.size ()) + if (lh->is_valid_file_index (file)) { - const file_entry &fe = lh->file_names[file - 1]; + const file_entry *fe = lh->file_name_at (file); - if (!IS_ABSOLUTE_PATH (fe.name)) + if (!IS_ABSOLUTE_PATH (fe->name)) { - const char *dir = fe.include_dir (lh); + const char *dir = fe->include_dir (lh); if (dir != NULL) - return concat (dir, SLASH_STRING, fe.name, (char *) NULL); + return concat (dir, SLASH_STRING, fe->name, (char *) NULL); } - return xstrdup (fe.name); + return xstrdup (fe->name); } else { @@ -24220,7 +24253,7 @@ file_full_name (int file, struct line_header *lh, const char *comp_dir) { /* Is the file number a valid index into the line header's file name table? Remember that file numbers start with one, not zero. */ - if (1 <= file && file <= lh->file_names.size ()) + if (lh->is_valid_file_index (file)) { char *relative = file_file_name (file, lh);