From 758ffab46b5b6c4f0a145e8833f24ba72a4259e4 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Thu, 21 Apr 2022 11:20:22 -0600 Subject: [PATCH] Fix crash when creating index from index My patches yesterday to unify the DWARF index base classes had a bug -- namely, I did the wholesale dynamic_cast-to-static_cast too hastily and introduced a crash. This can be seen by trying to add an index to a file that has an index, or by running a test like gdb-index-cxx.exp using the cc-with-debug-names.exp target board. This patch fixes the crash by introducing a new virtual method and removing some of the static casts. --- gdb/dwarf2/cooked-index.h | 5 +++++ gdb/dwarf2/index-write.c | 27 +++++++++------------------ gdb/dwarf2/mapped-index.h | 14 +++++++++++++- 3 files changed, 27 insertions(+), 19 deletions(-) diff --git a/gdb/dwarf2/cooked-index.h b/gdb/dwarf2/cooked-index.h index 21bda8698c1..a460351612f 100644 --- a/gdb/dwarf2/cooked-index.h +++ b/gdb/dwarf2/cooked-index.h @@ -295,6 +295,11 @@ public: "main". This will return NULL if no such entry is available. */ const cooked_index_entry *get_main () const; + cooked_index_vector *index_for_writing () override + { + return this; + } + quick_symbol_functions_up make_quick_functions () const override; private: diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index 62a7466bcfe..dfa74ddad8e 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -1163,8 +1163,9 @@ write_cooked_index (cooked_index_vector *table, associated dwz file, DWZ_OUT_FILE must be NULL. */ static void -write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file, - FILE *dwz_out_file) +write_gdbindex (dwarf2_per_objfile *per_objfile, + cooked_index_vector *table, + FILE *out_file, FILE *dwz_out_file) { mapped_symtab symtab; data_buf objfile_cu_list; @@ -1218,9 +1219,6 @@ write_gdbindex (dwarf2_per_objfile *per_objfile, FILE *out_file, ++this_counter; } - cooked_index_vector *table - = (static_cast - (per_objfile->per_bfd->index_table.get ())); write_cooked_index (table, cu_index_htab, &symtab); /* Dump the address map. */ @@ -1256,6 +1254,7 @@ static const gdb_byte dwarf5_gdb_augmentation[] = { 'G', 'D', 'B', 0 }; static void write_debug_names (dwarf2_per_objfile *per_objfile, + cooked_index_vector *table, FILE *out_file, FILE *out_file_str) { const bool dwarf5_is_dwarf64 = check_dwarf64_offsets (per_objfile); @@ -1291,9 +1290,6 @@ write_debug_names (dwarf2_per_objfile *per_objfile, - per_objfile->per_bfd->tu_stats.nr_tus)); gdb_assert (types_counter == per_objfile->per_bfd->tu_stats.nr_tus); - cooked_index_vector *table - = (static_cast - (per_objfile->per_bfd->index_table.get ())); for (const cooked_index_entry *entry : table->all_entries ()) nametable.insert (entry); @@ -1431,15 +1427,10 @@ write_dwarf_index (dwarf2_per_objfile *per_objfile, const char *dir, { struct objfile *objfile = per_objfile->objfile; + if (per_objfile->per_bfd->index_table == nullptr) + error (_("No debugging symbols")); cooked_index_vector *table - = (static_cast - (per_objfile->per_bfd->index_table.get ())); - if (table == nullptr) - { - if (per_objfile->per_bfd->index_table != nullptr) - error (_("Cannot use an index to create the index")); - error (_("No debugging symbols")); - } + = per_objfile->per_bfd->index_table->index_for_writing (); if (per_objfile->per_bfd->types.size () > 1) error (_("Cannot make an index when the file has multiple .debug_types sections")); @@ -1460,13 +1451,13 @@ write_dwarf_index (dwarf2_per_objfile *per_objfile, const char *dir, { index_wip_file str_wip_file (dir, basename, DEBUG_STR_SUFFIX); - write_debug_names (per_objfile, objfile_index_wip.out_file.get (), + write_debug_names (per_objfile, table, objfile_index_wip.out_file.get (), str_wip_file.out_file.get ()); str_wip_file.finalize (); } else - write_gdbindex (per_objfile, objfile_index_wip.out_file.get (), + write_gdbindex (per_objfile, table, objfile_index_wip.out_file.get (), (dwz_index_wip.has_value () ? dwz_index_wip->out_file.get () : NULL)); diff --git a/gdb/dwarf2/mapped-index.h b/gdb/dwarf2/mapped-index.h index e5d77469925..7d71347f9f4 100644 --- a/gdb/dwarf2/mapped-index.h +++ b/gdb/dwarf2/mapped-index.h @@ -1,6 +1,6 @@ /* Base class for mapped indices - Copyright (C) 2021 Free Software Foundation, Inc. + Copyright (C) 2021, 2022 Free Software Foundation, Inc. This file is part of GDB. @@ -47,6 +47,8 @@ struct name_component offset_type idx; }; +class cooked_index_vector; + /* Base class of all DWARF scanner types. */ struct dwarf_scanner_base @@ -66,6 +68,11 @@ struct dwarf_scanner_base { return true; } + + /* This is called when writing an index. For a cooked index, it + will return 'this' as a cooked index. For other forms, it will + throw an exception with an appropriate error message. */ + virtual cooked_index_vector *index_for_writing () = 0; }; /* Base class containing bits shared by both .gdb_index and @@ -109,6 +116,11 @@ struct mapped_index_base : public dwarf_scanner_base find_name_components_bounds (const lookup_name_info &ln_no_params, enum language lang, dwarf2_per_objfile *per_objfile) const; + + cooked_index_vector *index_for_writing () override + { + error (_("Cannot use an index to create the index")); + } }; #endif /* GDB_DWARF2_MAPPED_INDEX_H */ -- 2.30.2