readelf: Decode DW_AT_discr_list block attributes.

Decode DW_AT_descr_list blocks using the DW_DSC values.
This requires knowing the signedness of the discriminant.
Which means the attr_callback function needs access to the
parent DIE. Pass the whole DIE path, plus the current level.
That way the type of the discriminant can be looked up in
the variant_part (parent) DIE of the variant DIE (which has
the discr_list attribute).

Add a testcase using both signed and unsigned discriminants.

https://sourceware.org/bugzilla/show_bug.cgi?id=24509

Signed-off-by: Mark Wielaard <mark@klomp.org>
This commit is contained in:
Mark Wielaard
2019-05-05 23:18:36 +02:00
parent 7d029dc458
commit 643cbb275d
7 changed files with 453 additions and 10 deletions
+7
View File
@@ -1,3 +1,10 @@
2019-05-10 Mark Wielaard <mark@klomp.org>
* readelf.c (struct attrcb_args): Rename die to dies.
(attr_callback): Get current current die using dies[level].
Handle DW_AT_discr_list as block, not as constant.
(print_debug_units): pass dies, not dies[level] as args.
2019-05-09 Mark Wielaard <mark@klomp.org>
* readelf.c (cleanup_list): New function.
+95 -8
View File
@@ -6944,7 +6944,7 @@ struct attrcb_args
{
Dwfl_Module *dwflmod;
Dwarf *dbg;
Dwarf_Die *die;
Dwarf_Die *dies;
int level;
bool silent;
bool is_split;
@@ -6960,7 +6960,7 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
{
struct attrcb_args *cbargs = (struct attrcb_args *) arg;
const int level = cbargs->level;
Dwarf_Die *die = cbargs->die;
Dwarf_Die *die = &cbargs->dies[level];
bool is_split = cbargs->is_split;
unsigned int attr = dwarf_whatattr (attrp);
@@ -7304,9 +7304,6 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
case DW_AT_ordering:
valuestr = dwarf_ordering_name (num);
break;
case DW_AT_discr_list:
valuestr = dwarf_discr_list_name (num);
break;
case DW_AT_decl_file:
case DW_AT_call_file:
{
@@ -7361,7 +7358,7 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
/* When highpc is in constant form it is relative to lowpc.
In that case also show the address. */
Dwarf_Addr highpc;
if (attr == DW_AT_high_pc && dwarf_highpc (cbargs->die, &highpc) == 0)
if (attr == DW_AT_high_pc && dwarf_highpc (die, &highpc) == 0)
{
printf (" %*s%-20s (%s) %" PRIuMAX " (",
(int) (level * 2), "", dwarf_attr_name (attr),
@@ -7383,7 +7380,7 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
bool is_signed;
int bytes = 0;
if (attr == DW_AT_const_value)
die_type_sign_bytes (cbargs->die, &is_signed, &bytes);
die_type_sign_bytes (die, &is_signed, &bytes);
else
is_signed = (form == DW_FORM_sdata
|| form == DW_FORM_implicit_const);
@@ -7538,6 +7535,96 @@ attr_callback (Dwarf_Attribute *attrp, void *arg)
else
print_block (block.length, block.data);
break;
case DW_AT_discr_list:
if (block.length == 0)
puts ("<default>");
else if (form != DW_FORM_data16)
{
const unsigned char *readp = block.data;
const unsigned char *readendp = readp + block.length;
/* See if we are dealing with a signed or unsigned
values. If the parent of this variant DIE is a
variant_part then it will either have a discriminant
which points to the member which type is the
discriminant type. Or the variant_part itself has a
type representing the discriminant. */
bool is_signed = false;
if (level > 0)
{
Dwarf_Die *parent = &cbargs->dies[level - 1];
if (dwarf_tag (die) == DW_TAG_variant
&& dwarf_tag (parent) == DW_TAG_variant_part)
{
Dwarf_Die member;
Dwarf_Attribute discr_attr;
int bytes;
if (dwarf_formref_die (dwarf_attr (parent,
DW_AT_discr,
&discr_attr),
&member) != NULL)
die_type_sign_bytes (&member, &is_signed, &bytes);
else
die_type_sign_bytes (parent, &is_signed, &bytes);
}
}
while (readp < readendp)
{
int d = (int) *readp++;
printf ("%s ", dwarf_discr_list_name (d));
if (readp >= readendp)
goto attrval_out;
Dwarf_Word val;
Dwarf_Sword sval;
if (d == DW_DSC_label)
{
if (is_signed)
{
get_sleb128 (sval, readp, readendp);
printf ("%" PRId64 "", sval);
}
else
{
get_uleb128 (val, readp, readendp);
printf ("%" PRIu64 "", val);
}
}
else if (d == DW_DSC_range)
{
if (is_signed)
{
get_sleb128 (sval, readp, readendp);
printf ("%" PRId64 "..", sval);
if (readp >= readendp)
goto attrval_out;
get_sleb128 (sval, readp, readendp);
printf ("%" PRId64 "", sval);
}
else
{
get_uleb128 (val, readp, readendp);
printf ("%" PRIu64 "..", val);
if (readp >= readendp)
goto attrval_out;
get_uleb128 (val, readp, readendp);
printf ("%" PRIu64 "", val);
}
}
else
{
print_block (readendp - readp, readp);
break;
}
if (readp < readendp)
printf (", ");
}
putchar ('\n');
}
else
print_block (block.length, block.data);
break;
}
break;
@@ -7738,7 +7825,7 @@ print_debug_units (Dwfl_Module *dwflmod,
/* Print the attribute values. */
args.level = level;
args.die = &dies[level];
args.dies = dies;
(void) dwarf_getattrs (&dies[level], attr_callback, &args, 0);
/* Make room for the next level's DIE. */
+9
View File
@@ -1,3 +1,12 @@
2019-05-10 Mark Wielaard <mark@klomp.org>
* Makefile.am (TESTS): Add run-readelf-discr.sh.
(EXTRA_DIST): Likewise and add testfile-rng.debug.bz2 and
testfile-urng.debug.bz2.
* run-readelf-discr.sh: New test.
* testfile-rng.debug.bz2: New test file.
* testfile-urng.debug.bz2: Likewise.
2019-04-30 Mark Wielaard <mark@klomp.org>
* xlate_notes.c: New file.
+5 -2
View File
@@ -159,7 +159,8 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile test-nlist \
run-next-cfi.sh run-next-cfi-self.sh \
run-copyadd-sections.sh run-copymany-sections.sh \
run-typeiter-many.sh run-strip-test-many.sh \
run-strip-version.sh run-xlate-note.sh
run-strip-version.sh run-xlate-note.sh \
run-readelf-discr.sh
if !BIARCH
export ELFUTILS_DISABLE_BIARCH = 1
@@ -424,7 +425,9 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
testfile-debug-rel-ppc64-z.o.bz2 \
testfile-debug-rel-ppc64.o.bz2 \
run-strip-version.sh testfile-version.bz2 \
run-xlate-note.sh
run-xlate-note.sh \
run-readelf-discr.sh \
testfile-rng.debug.bz2 testfile-urng.debug.bz2
if USE_VALGRIND
valgrind_cmd='valgrind -q --leak-check=full --error-exitcode=1'
+337
View File
@@ -0,0 +1,337 @@
#! /bin/sh
# Copyright (C) 2019 Red Hat, Inc.
# This file is part of elfutils.
#
# This file 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.
#
# elfutils 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 <http://www.gnu.org/licenses/>.
. $srcdir/test-subr.sh
# = rng.ads =
# package Rng is
#
# type Rec (I : Integer) is record
# case I is
# when Positive =>
# case I is
# when 1..15 | 17 | 23 =>
# null;
# when others =>
# J : Integer;
# end case;
# when -52..-1 =>
# Q: Integer;
# when -64 =>
# R: Boolean;
# when others =>
# null;
# end case;
# end record;
#
# R : Rec (1);
#
# end Rng;
# = urng.ads =
#
# package Urng is
#
# type Unsigned is mod 65536;
# type Rec (U : Unsigned) is record
# case U is
# when 17 | 23 | 32768..65535 =>
# null;
# when 256 =>
# B: Boolean;
# when others =>
# I : Integer;
# end case;
# end record;
#
# R : Rec (1);
#
# end Urng;
# gcc -c -g -fgnat-encodings=minimal -gstrict-dwarf rng.ads
# eu-strip -g -f rng.debug rng.o
# gcc -c -g -fgnat-encodings=minimal -gstrict-dwarf urng.ads
# eu-strip -g -f urng.debug urng.o
testfiles testfile-rng.debug testfile-urng.debug
testrun_compare ${abs_top_builddir}/src/readelf -U --debug-dump=info testfile-rng.debug testfile-urng.debug <<EOF
testfile-rng.debug:
DWARF section [ 5] '.debug_info' at offset 0x40:
[Offset]
Compilation unit at offset 0:
Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
[ b] compile_unit abbrev: 1
producer (strp) "GNU Ada 9.1.1 20190503 (Red Hat 9.1.1-1) -g -fgnat-encodings=minimal -gstrict-dwarf -mtune=generic -march=x86-64"
language (data1) Ada95 (13)
name (strp) "rng.ads"
comp_dir (strp) "/home/mark"
low_pc (addr) 000000000000000000
high_pc (data8) 2016 (0x00000000000007e0)
stmt_list (sec_offset) 0
[ 2d] structure_type abbrev: 2
name (strp) "rng__rec"
byte_size (exprloc)
[ 0] push_object_address
[ 1] deref_size 4
[ 3] call4 [ c6]
[ 8] plus_uconst 7
[10] const1s -4
[12] and
decl_file (data1) rng.ads (1)
decl_line (data1) 3
decl_column (data1) 9
sibling (ref4) [ ab]
[ 47] member abbrev: 3
name (string) "i"
decl_file (data1) rng.ads (1)
decl_line (data1) 3
decl_column (data1) 14
type (ref4) [ fe]
data_member_location (data1) 0
[ 52] variant_part abbrev: 4
discr (ref4) [ 47]
[ 57] variant abbrev: 5
discr_list (block1) range 1..2147483647
sibling (ref4) [ 81]
[ 64] variant_part abbrev: 4
discr (ref4) [ 47]
[ 69] variant abbrev: 6
discr_list (block1) range 1..15, label 17, label 23
[ 72] variant abbrev: 7
[ 73] member abbrev: 3
name (string) "j"
decl_file (data1) rng.ads (1)
decl_line (data1) 10
decl_column (data1) 19
type (ref4) [ fe]
data_member_location (data1) 4
[ 81] variant abbrev: 5
discr_list (block1) range -52..-1
sibling (ref4) [ 96]
[ 8a] member abbrev: 3
name (string) "q"
decl_file (data1) rng.ads (1)
decl_line (data1) 13
decl_column (data1) 13
type (ref4) [ fe]
data_member_location (data1) 4
[ 96] variant abbrev: 8
discr_value (sdata) -64
sibling (ref4) [ a8]
[ 9c] member abbrev: 3
name (string) "r"
decl_file (data1) rng.ads (1)
decl_line (data1) 15
decl_column (data1) 13
type (ref4) [ 105]
data_member_location (data1) 4
[ a8] variant abbrev: 9
[ ab] dwarf_procedure abbrev: 10
location (exprloc)
[ 0] dup
[ 1] lit0
[ 2] gt
[ 3] over
[ 4] lit15
[ 5] le
[ 6] and
[ 7] over
[ 8] lit17
[ 9] eq
[10] or
[11] over
[12] lit23
[13] eq
[14] or
[15] bra 22
[18] lit4
[19] skip 23
[22] lit0
[23] swap
[24] drop
[ c6] dwarf_procedure abbrev: 10
location (exprloc)
[ 0] dup
[ 1] lit0
[ 2] gt
[ 3] bra 36
[ 6] dup
[ 7] const1s -52
[ 9] lt
[10] over
[11] lit0
[12] ge
[13] or
[14] bra 21
[17] lit4
[18] skip 33
[21] dup
[22] const1s -64
[24] eq
[25] bra 32
[28] lit0
[29] skip 33
[32] lit4
[33] skip 52
[36] dup
[37] call4 [ ab]
[42] plus_uconst 3
[44] const1s -4
[46] and
[47] plus_uconst 3
[49] const1s -4
[51] and
[52] swap
[53] drop
[ fe] base_type abbrev: 11
byte_size (data1) 4
encoding (data1) signed (5)
name (strp) "integer"
artificial (flag_present) yes
[ 105] base_type abbrev: 12
byte_size (data1) 1
encoding (data1) boolean (2)
name (strp) "boolean"
[ 10c] variable abbrev: 13
name (strp) "rng__r"
decl_file (data1) rng.ads (1)
decl_line (data1) 21
decl_column (data1) 4
type (ref4) [ 2d]
external (flag_present) yes
location (exprloc)
[ 0] addr 0x7e4
[ 122] subprogram abbrev: 14
external (flag_present) yes
name (strp) "rng___elabs"
artificial (flag_present) yes
low_pc (addr) 0x0000000000000734
high_pc (data8) 22 (0x000000000000074a)
frame_base (exprloc)
[ 0] call_frame_cfa
testfile-urng.debug:
DWARF section [ 5] '.debug_info' at offset 0x40:
[Offset]
Compilation unit at offset 0:
Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
[ b] compile_unit abbrev: 1
producer (strp) "GNU Ada 9.1.1 20190503 (Red Hat 9.1.1-1) -g -fgnat-encodings=minimal -gstrict-dwarf -mtune=generic -march=x86-64"
language (data1) Ada95 (13)
name (strp) "urng.ads"
comp_dir (strp) "/home/mark"
low_pc (addr) 000000000000000000
high_pc (data8) 977 (0x00000000000003d1)
stmt_list (sec_offset) 0
[ 2d] base_type abbrev: 2
byte_size (data1) 2
encoding (data1) unsigned (7)
name (strp) "urng__unsigned"
[ 34] structure_type abbrev: 3
name (strp) "urng__rec"
byte_size (exprloc)
[ 0] push_object_address
[ 1] deref_size 2
[ 3] call4 [ 8d]
[ 8] plus_uconst 7
[10] const1s -4
[12] and
decl_file (data1) urng.ads (1)
decl_line (data1) 4
decl_column (data1) 9
sibling (ref4) [ 8d]
[ 4e] member abbrev: 4
name (string) "u"
decl_file (data1) urng.ads (1)
decl_line (data1) 4
decl_column (data1) 14
type (ref4) [ 2d]
data_member_location (data1) 0
[ 59] variant_part abbrev: 5
discr (ref4) [ 4e]
[ 5e] variant abbrev: 6
discr_list (block1) label 17, label 23, range 32768..65535
[ 6b] variant abbrev: 7
discr_value (udata) 256
sibling (ref4) [ 7e]
[ 72] member abbrev: 4
name (string) "b"
decl_file (data1) urng.ads (1)
decl_line (data1) 9
decl_column (data1) 13
type (ref4) [ a4]
data_member_location (data1) 4
[ 7e] variant abbrev: 8
[ 7f] member abbrev: 4
name (string) "i"
decl_file (data1) urng.ads (1)
decl_line (data1) 11
decl_column (data1) 13
type (ref4) [ ab]
data_member_location (data1) 4
[ 8d] dwarf_procedure abbrev: 9
location (exprloc)
[ 0] dup
[ 1] lit17
[ 2] ne
[ 3] over
[ 4] lit23
[ 5] ne
[ 6] and
[ 7] over
[ 8] lit0
[ 9] ge
[10] and
[11] bra 18
[14] lit0
[15] skip 19
[18] lit4
[19] swap
[20] drop
[ a4] base_type abbrev: 2
byte_size (data1) 1
encoding (data1) boolean (2)
name (strp) "boolean"
[ ab] base_type abbrev: 10
byte_size (data1) 4
encoding (data1) signed (5)
name (strp) "integer"
artificial (flag_present) yes
[ b2] variable abbrev: 11
name (strp) "urng__r"
decl_file (data1) urng.ads (1)
decl_line (data1) 15
decl_column (data1) 4
type (ref4) [ 34]
external (flag_present) yes
location (exprloc)
[ 0] addr 0x3d8
[ c8] subprogram abbrev: 12
external (flag_present) yes
name (strp) "urng___elabs"
artificial (flag_present) yes
low_pc (addr) 0x0000000000000386
high_pc (data8) 22 (0x000000000000039c)
frame_base (exprloc)
[ 0] call_frame_cfa
EOF
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