diff options
| -rw-r--r-- | gdb/NEWS | 3 | ||||
| -rw-r--r-- | gdb/doc/gdb.texinfo | 23 | ||||
| -rw-r--r-- | gdb/dwarf2/index-write.c | 54 | ||||
| -rw-r--r-- | gdb/dwarf2/read-gdb-index.c | 54 | ||||
| -rw-r--r-- | gdb/dwarf2/read.c | 13 | ||||
| -rw-r--r-- | gdb/dwarf2/read.h | 12 |
6 files changed, 146 insertions, 13 deletions
@@ -3,6 +3,9 @@ *** Changes since GDB 14 +* GDB index now contains information about the main function. This speeds up + startup when it is being used for some large binaries. + *** Changes in GDB 14 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 4932e49..db1a82e 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -49663,13 +49663,14 @@ unless otherwise noted: @enumerate @item -The version number, currently 8. Versions 1, 2 and 3 are obsolete. +The version number, currently 9. Versions 1, 2 and 3 are obsolete. Version 4 uses a different hashing function from versions 5 and 6. Version 6 includes symbols for inlined functions, whereas versions 4 and 5 do not. Version 7 adds attributes to the CU indices in the symbol table. Version 8 specifies that symbols from DWARF type units (@samp{DW_TAG_type_unit}) refer to the type unit's symbol table and not the -compilation unit (@samp{DW_TAG_comp_unit}) using the type. +compilation unit (@samp{DW_TAG_comp_unit}) using the type. Version 9 adds +the name and the language of the main function to the index. @value{GDBN} will only read version 4, 5, or 6 indices by specifying @code{set use-deprecated-index-sections on}. @@ -49691,6 +49692,9 @@ The offset, from the start of the file, of the address area. The offset, from the start of the file, of the symbol table. @item +The offset, from the start of the file, of the shortcut table. + +@item The offset, from the start of the file, of the constant pool. @end enumerate @@ -49766,6 +49770,21 @@ don't currently have a simple description of the canonicalization algorithm; if you intend to create new index sections, you must read the code. +@item The shortcut table +This is a data structure with the following fields: + +@table @asis +@item Language of main +An @code{offset_type} value indicating the language of the main function as a +@code{DW_LANG_} constant. This value will be zero if main function information +is not present. + +@item Name of main +An @code{offset_type} value indicating the offset of the main function's name +in the constant pool. This value must be ignored if the value for the language +of main is zero. +@end table + @item The constant pool. This is simply a bunch of bytes. It is organized so that alignment is correct: CU vectors are stored first, followed by diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index 3acff26..6ea4217 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -1079,14 +1079,15 @@ write_gdbindex_1 (FILE *out_file, const data_buf &types_cu_list, const data_buf &addr_vec, const data_buf &symtab_vec, - const data_buf &constant_pool) + const data_buf &constant_pool, + const data_buf &shortcuts) { data_buf contents; - const offset_type size_of_header = 6 * sizeof (offset_type); + const offset_type size_of_header = 7 * sizeof (offset_type); uint64_t total_len = size_of_header; /* The version number. */ - contents.append_offset (8); + contents.append_offset (9); /* The offset of the CU list from the start of the file. */ contents.append_offset (total_len); @@ -1104,6 +1105,10 @@ write_gdbindex_1 (FILE *out_file, contents.append_offset (total_len); total_len += symtab_vec.size (); + /* The offset of the shortcut table from the start of the file. */ + contents.append_offset (total_len); + total_len += shortcuts.size (); + /* The offset of the constant pool from the start of the file. */ contents.append_offset (total_len); total_len += constant_pool.size (); @@ -1125,6 +1130,7 @@ write_gdbindex_1 (FILE *out_file, types_cu_list.file_write (out_file); addr_vec.file_write (out_file); symtab_vec.file_write (out_file); + shortcuts.file_write (out_file); constant_pool.file_write (out_file); assert_file_size (out_file, total_len); @@ -1187,6 +1193,34 @@ write_cooked_index (cooked_index *table, } } +/* Write shortcut information. */ + +static void +write_shortcuts_table (cooked_index *table, data_buf& shortcuts, + data_buf& cpool) +{ + const auto main_info = table->get_main (); + size_t main_name_offset = 0; + dwarf_source_language dw_lang = (dwarf_source_language)0; + + if (main_info != nullptr) + { + dw_lang = main_info->per_cu->dw_lang; + + if (dw_lang != 0) + { + auto_obstack obstack; + const auto main_name = main_info->full_name (&obstack, true); + + main_name_offset = cpool.size (); + cpool.append_cstr0 (main_name); + } + } + + shortcuts.append_uint (4, BFD_ENDIAN_LITTLE, dw_lang); + shortcuts.append_offset (main_name_offset); +} + /* Write contents of a .gdb_index section for OBJFILE into OUT_FILE. If OBJFILE has an associated dwz file, write contents of a .gdb_index section for that dwz file into DWZ_OUT_FILE. If OBJFILE does not have an @@ -1263,11 +1297,14 @@ write_gdbindex (dwarf2_per_bfd *per_bfd, cooked_index *table, write_hash_table (&symtab, symtab_vec, constant_pool); + data_buf shortcuts; + write_shortcuts_table (table, shortcuts, constant_pool); + write_gdbindex_1(out_file, objfile_cu_list, types_cu_list, addr_vec, - symtab_vec, constant_pool); + symtab_vec, constant_pool, shortcuts); if (dwz_out_file != NULL) - write_gdbindex_1 (dwz_out_file, dwz_cu_list, {}, {}, {}, {}); + write_gdbindex_1 (dwz_out_file, dwz_cu_list, {}, {}, {}, {}, {}); else gdb_assert (dwz_cu_list.empty ()); } @@ -1573,8 +1610,9 @@ gdb_index () pretend_data_buf addr_vec; pretend_data_buf symtab_vec; pretend_data_buf constant_pool; + pretend_data_buf short_cuts; - const size_t size_of_header = 6 * sizeof (offset_type); + const size_t size_of_header = 7 * sizeof (offset_type); /* Test that an overly large index will throw an error. */ symtab_vec.set_pretend_size (~(offset_type)0 - size_of_header); @@ -1584,7 +1622,7 @@ gdb_index () try { write_gdbindex_1 (nullptr, cu_list, types_cu_list, addr_vec, - symtab_vec, constant_pool); + symtab_vec, constant_pool, short_cuts); } catch (const gdb_exception_error &e) { @@ -1604,7 +1642,7 @@ gdb_index () try { write_gdbindex_1 (nullptr, cu_list, types_cu_list, addr_vec, - symtab_vec, constant_pool); + symtab_vec, constant_pool, short_cuts); } catch (const gdb_exception_error &e) { diff --git a/gdb/dwarf2/read-gdb-index.c b/gdb/dwarf2/read-gdb-index.c index 9bfc530..b96eaa9 100644 --- a/gdb/dwarf2/read-gdb-index.c +++ b/gdb/dwarf2/read-gdb-index.c @@ -88,6 +88,9 @@ struct mapped_gdb_index final : public mapped_index_base /* A pointer to the constant pool. */ gdb::array_view<const gdb_byte> constant_pool; + /* The shortcut table data. */ + gdb::array_view<const gdb_byte> shortcut_table; + /* Return the index into the constant pool of the name of the IDXth symbol in the symbol table. */ offset_type symbol_name_index (offset_type idx) const @@ -583,7 +586,7 @@ to use the section anyway."), /* Indexes with higher version than the one supported by GDB may be no longer backward compatible. */ - if (version > 8) + if (version > 9) return 0; map->version = version; @@ -610,6 +613,16 @@ to use the section anyway."), symbol_table_end)); ++i; + + if (version >= 9) + { + const gdb_byte *shortcut_table = addr + metadata[i]; + const gdb_byte *shortcut_table_end = addr + metadata[i + 1]; + map->shortcut_table + = gdb::array_view<const gdb_byte> (shortcut_table, shortcut_table_end); + ++i; + } + map->constant_pool = buffer.slice (metadata[i]); if (map->constant_pool.empty () && !map->symbol_table.empty ()) @@ -758,6 +771,43 @@ create_addrmap_from_gdb_index (dwarf2_per_objfile *per_objfile, = new (&per_bfd->obstack) addrmap_fixed (&per_bfd->obstack, &mutable_map); } +/* Sets the name and language of the main function from the shortcut table. */ + +static void +set_main_name_from_gdb_index (dwarf2_per_objfile *per_objfile, + mapped_gdb_index *index) +{ + const auto expected_size = 4 + sizeof (offset_type); + if (index->shortcut_table.size () < expected_size) + /* The data in the section is not present, is corrupted or is in a version + * we don't know about. Regardless, we can't make use of it. */ + return; + + auto ptr = index->shortcut_table.data (); + const auto dw_lang = extract_unsigned_integer (ptr, 4, BFD_ENDIAN_LITTLE); + if (dw_lang >= DW_LANG_hi_user) + { + complaint (_(".gdb_index shortcut table has invalid main language %u"), + (unsigned) dw_lang); + return; + } + if (dw_lang == 0) + { + /* Don't bother if the language for the main symbol was not known or if + * there was no main symbol at all when the index was built. */ + return; + } + ptr += 4; + + const auto lang = dwarf_lang_to_enum_language (dw_lang); + const auto name_offset = extract_unsigned_integer (ptr, + sizeof (offset_type), + BFD_ENDIAN_LITTLE); + const auto name = (const char*) (index->constant_pool.data () + name_offset); + + set_objfile_main_name (per_objfile->objfile, name, (enum language) lang); +} + /* See read-gdb-index.h. */ int @@ -843,6 +893,8 @@ dwarf2_read_gdb_index create_addrmap_from_gdb_index (per_objfile, map.get ()); + set_main_name_from_gdb_index (per_objfile, map.get ()); + per_bfd->index_table = std::move (map); per_bfd->quick_file_names_table = create_quick_file_names_table (per_bfd->all_units.size ()); diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 5bbc8e2..d4aec19 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -17796,7 +17796,9 @@ leb128_size (const gdb_byte *buf) } } -static enum language +/* Converts DWARF language names to GDB language names. */ + +enum language dwarf_lang_to_enum_language (unsigned int lang) { enum language language; @@ -21725,6 +21727,7 @@ prepare_one_comp_unit (struct dwarf2_cu *cu, struct die_info *comp_unit_die, /* Set the language we're debugging. */ attr = dwarf2_attr (comp_unit_die, DW_AT_language, cu); enum language lang; + dwarf_source_language dw_lang = (dwarf_source_language)0; if (cu->producer != nullptr && strstr (cu->producer, "IBM XL C for OpenCL") != NULL) { @@ -21733,18 +21736,24 @@ prepare_one_comp_unit (struct dwarf2_cu *cu, struct die_info *comp_unit_die, language detection we fall back to the DW_AT_producer string. */ lang = language_opencl; + dw_lang = DW_LANG_OpenCL; } else if (cu->producer != nullptr && strstr (cu->producer, "GNU Go ") != NULL) { /* Similar hack for Go. */ lang = language_go; + dw_lang = DW_LANG_Go; } else if (attr != nullptr) - lang = dwarf_lang_to_enum_language (attr->constant_value (0)); + { + lang = dwarf_lang_to_enum_language (attr->constant_value (0)); + dw_lang = (dwarf_source_language)attr->constant_value (0); + } else lang = pretend_language; + cu->per_cu->dw_lang = dw_lang; cu->language_defn = language_def (lang); switch (comp_unit_die->tag) diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h index 9dfc435..1d9432c 100644 --- a/gdb/dwarf2/read.h +++ b/gdb/dwarf2/read.h @@ -245,6 +245,14 @@ public: functions above. */ std::vector <dwarf2_per_cu_data *> *imported_symtabs = nullptr; + /* The original DW_LANG_* value of the CU, as provided to us by + * DW_AT_language. It is interesting to keep this value around in cases where + * we can't use the values from the language enum, as the mapping to them is + * lossy, and, while that is usually fine, things like the index have an + * understandable bias towards not exposing internal GDB structures to the + * outside world, and so prefer to use DWARF constants in their stead. */ + dwarf_source_language dw_lang; + /* Return true of IMPORTED_SYMTABS is empty or not yet allocated. */ bool imported_symtabs_empty () const { @@ -764,6 +772,10 @@ private: std::unique_ptr<dwarf2_cu>> m_dwarf2_cus; }; +/* Converts DWARF language names to GDB language names. */ + +enum language dwarf_lang_to_enum_language (unsigned int lang); + /* Get the dwarf2_per_objfile associated to OBJFILE. */ dwarf2_per_objfile *get_dwarf2_per_objfile (struct objfile *objfile); |