http://sourceware.org/ml/gdb-patches/2010-03/msg01039.html Subject: [patch] Fix crash on NULL function's TYPE_FIELD_TYPE Hi, seen one possibility of a crash. #0 c_print_type (type=0x0, ...) #1 in c_type_print_args (type=0xfceb890, (The real reason of a reported GDB crash was different, though.) Thanks, Jan gdb/ 2010-03-30 Jan Kratochvil Fix crash on reading wrong function declaration DWARF. * dwarf2read.c (read_subroutine_type): New variable void_type. Pre-fill all TYPE_FIELD_TYPEs. Move nparams and iparams initialization more close to their use. gdb/testsuite/ 2010-03-30 Jan Kratochvil * gdb.dwarf2/dw2-bad-parameter-type.exp, gdb.dwarf2/dw2-bad-parameter-type.S: New. --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -5938,13 +5938,14 @@ read_subroutine_type (struct die_info *die, struct dwarf2_cu *cu) if (die->child != NULL) { + struct type *void_type = objfile_type (cu->objfile)->builtin_void; struct die_info *child_die; - int nparams = 0; - int iparams = 0; + int nparams, iparams; /* Count the number of parameters. FIXME: GDB currently ignores vararg functions, but knows about vararg member functions. */ + nparams = 0; child_die = die->child; while (child_die && child_die->tag) { @@ -5960,6 +5961,12 @@ read_subroutine_type (struct die_info *die, struct dwarf2_cu *cu) TYPE_FIELDS (ftype) = (struct field *) TYPE_ZALLOC (ftype, nparams * sizeof (struct field)); + /* TYPE_FIELD_TYPE must never be NULL. Pre-fill the array to ensure it + even if we error out during the parameters reading below. */ + for (iparams = 0; iparams < nparams; iparams++) + TYPE_FIELD_TYPE (ftype, iparams) = void_type; + + iparams = 0; child_die = die->child; while (child_die && child_die->tag) { --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-bad-parameter-type.S @@ -0,0 +1,73 @@ +/* Copyright 2010 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + + .section .debug_info +debug_start: + .long debug_end - 1f /* Length of Compilation Unit Info */ +1: + .2byte 0x3 /* DWARF version number */ + .long .Ldebug_abbrev0 /* Offset Into Abbrev. Section */ + .byte 0x4 /* Pointer Size (in bytes) */ + .uleb128 0x1 /* (DIE (0xb) DW_TAG_compile_unit) */ + .ascii "GNU C 4.4.3\0" /* DW_AT_producer */ + .byte 0x1 /* DW_AT_language */ + .ascii "1.c\0" /* DW_AT_name */ + .uleb128 0x4 /* (DIE (0x3c) DW_TAG_subprogram) */ + .ascii "f\0" /* DW_AT_name */ +/* Value 0 would require has_section_at_zero != 0 (which is true, though). */ + .long 1 /* DW_AT_low_pc */ + .long 2 /* DW_AT_high_pc */ + .byte 0x1 /* DW_AT_prototyped */ + .uleb128 0x5 /* (DIE (0x42) DW_TAG_formal_parameter) */ +/* Invalid value. */ + .long 0x0 /* DW_AT_type */ + .byte 0x0 /* end of children of DIE 0x3c */ + .byte 0x0 /* end of children of DIE 0xb */ +debug_end: + + .section .debug_abbrev +.Ldebug_abbrev0: + .uleb128 0x1 /* (abbrev code) */ + .uleb128 0x11 /* (TAG: DW_TAG_compile_unit) */ + .byte 0x1 /* DW_children_yes */ + .uleb128 0x25 /* (DW_AT_producer) */ + .uleb128 0x8 /* (DW_FORM_string) */ + .uleb128 0x13 /* (DW_AT_language) */ + .uleb128 0xb /* (DW_FORM_data1) */ + .uleb128 0x3 /* (DW_AT_name) */ + .uleb128 0x8 /* (DW_FORM_string) */ + .byte 0x0 + .byte 0x0 + .uleb128 0x4 /* (abbrev code) */ + .uleb128 0x2e /* (TAG: DW_TAG_subprogram) */ + .byte 0x1 /* DW_children_yes */ + .uleb128 0x3 /* (DW_AT_name) */ + .uleb128 0x8 /* (DW_FORM_string) */ + .uleb128 0x11 /* (DW_AT_low_pc) */ + .uleb128 0x1 /* (DW_FORM_addr) */ + .uleb128 0x12 /* (DW_AT_high_pc) */ + .uleb128 0x1 /* (DW_FORM_addr) */ + .uleb128 0x27 /* (DW_AT_prototyped) */ + .uleb128 0xc /* (DW_FORM_flag) */ + .byte 0x0 + .byte 0x0 + .uleb128 0x5 /* (abbrev code) */ + .uleb128 0x5 /* (TAG: DW_TAG_formal_parameter) */ + .byte 0x0 /* DW_children_no */ + .uleb128 0x49 /* (DW_AT_type) */ + .uleb128 0x13 /* (DW_FORM_ref4) */ + .byte 0x0 + .byte 0x0 + .byte 0x0 --- /dev/null +++ b/gdb/testsuite/gdb.dwarf2/dw2-bad-parameter-type.exp @@ -0,0 +1,44 @@ +# Copyright 2010 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# This test can only be run on targets which support DWARF-2 and use gas. +# For now pick a sampling of likely targets. +if {![istarget *-*-linux*] + && ![istarget *-*-gnu*] + && ![istarget *-*-elf*] + && ![istarget *-*-openbsd*] + && ![istarget arm-*-eabi*] + && ![istarget powerpc-*-eabi*]} { + return 0 +} + +set testfile "dw2-bad-parameter-type" +set srcfile ${testfile}.S +set executable ${testfile}.x +set binfile ${objdir}/${subdir}/${executable} + +# First try referencing DW_AT_frame_base which is not defined. +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" object {}] != "" } { + return -1 +} + +clean_restart $executable + +# The first access (as we do not use -readnow) prints some: +# Dwarf Error: Cannot find DIE at 0x0 referenced from DIE at 0x29 [in module ...] +gdb_test "ptype f" + +gdb_test "ptype f" +gdb_test "p 5" " = 5" "is alive"