From 7b5d965008fee110409d054a787a7d825bc44436 Mon Sep 17 00:00:00 2001 From: Fred Fish Date: Wed, 12 Aug 1992 18:17:48 +0000 Subject: [PATCH] * buildsym.c (end_symtab): Document that end_symtab can return NULL under non-error conditions. * dwarfread.c (read_file_scope): Guard against dereferencing NULL returned from end_symtab for empty compilation units. --- gdb/ChangeLog | 7 +++++++ gdb/buildsym.c | 9 ++++++++- gdb/dwarfread.c | 27 +++++++++++++++------------ 3 files changed, 30 insertions(+), 13 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 54df4ab94fd..f707ab8c7b9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +Wed Aug 12 11:14:58 1992 Fred Fish (fnf@cygnus.com) + + * buildsym.c (end_symtab): Document that end_symtab can return + NULL under non-error conditions. + * dwarfread.c (read_file_scope): Guard against dereferencing NULL + returned from end_symtab for empty compilation units. + Tue Aug 11 02:49:39 1992 John Gilmore (gnu at cygnus.com) * am29k-tdep.c: Lint from DECstation compiler. diff --git a/gdb/buildsym.c b/gdb/buildsym.c index e0f69cddc61..566a66f860a 100644 --- a/gdb/buildsym.c +++ b/gdb/buildsym.c @@ -549,7 +549,14 @@ start_symtab (name, dirname, start_addr) (creating struct block's for them), then make the struct symtab for that file and put it in the list of all such. - END_ADDR is the address of the end of the file's text. */ + END_ADDR is the address of the end of the file's text. + + Note that it is possible for end_symtab() to return NULL. In particular, + for the DWARF case at least, it will return NULL when it finds a + compilation unit that has exactly one DIE, a TAG_compile_unit DIE. This + can happen when we link in an object file that was compiled from an empty + source file. Returning NULL is probably not the correct thing to do, + because then gdb will never know about this empty file (FIXME). */ struct symtab * end_symtab (end_addr, sort_pending, sort_linevec, objfile) diff --git a/gdb/dwarfread.c b/gdb/dwarfread.c index c16c21ac70f..fcca11c72f5 100644 --- a/gdb/dwarfread.c +++ b/gdb/dwarfread.c @@ -1662,19 +1662,22 @@ read_file_scope (dip, thisdie, enddie, objfile) decode_line_numbers (lnbase); process_dies (thisdie + dip -> die_length, enddie, objfile); symtab = end_symtab (dip -> at_high_pc, 0, 0, objfile); - /* FIXME: The following may need to be expanded for other languages */ - switch (dip -> at_language) + if (symtab != NULL) { - case LANG_C89: - case LANG_C: - symtab -> language = language_c; - break; - case LANG_C_PLUS_PLUS: - symtab -> language = language_cplus; - break; - default: - ; - } + /* FIXME: The following may need to be expanded for other languages */ + switch (dip -> at_language) + { + case LANG_C89: + case LANG_C: + symtab -> language = language_c; + break; + case LANG_C_PLUS_PLUS: + symtab -> language = language_cplus; + break; + default: + ; + } + } do_cleanups (back_to); utypes = NULL; numutypes = 0; -- 2.30.2