From patchwork Thu Dec 14 21:26:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Seitz X-Patchwork-Id: 24949 Received: (qmail 39651 invoked by alias); 14 Dec 2017 21:26:52 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 39594 invoked by uid 89); 14 Dec 2017 21:26:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_HELO_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=reminded, traced, calculations, 2101 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 14 Dec 2017 21:26:49 +0000 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B0995883A4 for ; Thu, 14 Dec 2017 21:26:48 +0000 (UTC) Received: from theo.uglyboxes.com (ovpn04.gateway.prod.ext.phx2.redhat.com [10.5.9.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 92D1471D7C; Thu, 14 Dec 2017 21:26:47 +0000 (UTC) From: Keith Seitz To: gdb-patches@sourceware.org Subject: [PATCH v2] Compute proper length for dynamic types of TYPE_CODE_TYPEDEF Date: Thu, 14 Dec 2017 13:26:47 -0800 Message-Id: <20171214212647.5692-1-keiths@redhat.com> X-IsSubscribed: yes This bug has recently appeared again and someone reminded me that this patch is still outstanding (thanks, Jan!). Pedro reviewed this in June. Revisions in v2: - Added some comments to the test case - Renamed types/variables in the test case - Added initializer for previously uninitialized structure member Keith ----- This patch fixes gdb/21356 in which we hit an assertion in value_contents_bits_eq: (gdb) p container_object2 (gdb) p container_object2 $1 = {_container_member2 = 15, _vla_struct_object2 = {_some_member = 0, _vla_field = { ../../src/gdb/value.c:829: internal-error: int value_contents_bits_eq(const value*, int, const value*, int, int): Assertion `offset1 + length <= TYPE_LENGTH (val1->enclosing_type) * TARGET_CHAR_BIT' failed. A problem internal to GDB has been detected, further debugging may prove unreliable. Quit this debugging session? (y or n) This is happening because TYPE_LENGTH (val1->enclosing_type) is erroneously based on enclosing_type, which is a typedef, instead of the actual underlying type. This can be traced back to resolve_dynamic_struct, where the size of the type is computed: 2093 TYPE_FIELD_TYPE (resolved_type, i) 2094 = resolve_dynamic_type_internal (TYPE_FIELD_TYPE (resolved_type, i), 2095 &pinfo, 0); 2096 gdb_assert (TYPE_FIELD_LOC_KIND (resolved_type, i) 2097 == FIELD_LOC_KIND_BITPOS); 2098 2099 new_bit_length = TYPE_FIELD_BITPOS (resolved_type, i); 2100 if (TYPE_FIELD_BITSIZE (resolved_type, i) != 0) 2101 new_bit_length += TYPE_FIELD_BITSIZE (resolved_type, i); 2102 else 2103 new_bit_length += (TYPE_LENGTH (TYPE_FIELD_TYPE (resolved_type, i)) 2104 * TARGET_CHAR_BIT); In this function, resolved_type is TYPE_CODE_TYPEDEF which is not what we want to use to calculate the size of the actual field. This patch fixes this and the similar problem in resolve_dynamic_union. gdb/ChangeLog: PR gdb/21356 * gdbtypes.c (resolve_dynamic_union, resolve_dynamic_struct): Resolve typedefs for type length calculations. gdb/testsuite/ChangeLog: PR gdb/21356 * gdb.base/vla-datatypes.c (vla_factory): Add typedef for struct vla_struct. Add new struct vla_struct_with_vla_typedef and union vla_union_with_vla_typedef and corresponding instantiation objects. Initialize new objects. * gdb.base/vla-datatypes.exp: Add tests for vla_struct_with_vla_typedef_object and vla_union_with_vla_typedef_object. Fixup type for vla_struct_object. --- gdb/gdbtypes.c | 14 ++++++++++---- gdb/testsuite/gdb.base/vla-datatypes.c | 28 ++++++++++++++++++++++++++-- gdb/testsuite/gdb.base/vla-datatypes.exp | 6 +++++- 3 files changed, 41 insertions(+), 7 deletions(-) diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c index 01ab6fa8c7..0df5ee1286 100644 --- a/gdb/gdbtypes.c +++ b/gdb/gdbtypes.c @@ -2036,8 +2036,10 @@ resolve_dynamic_union (struct type *type, t = resolve_dynamic_type_internal (TYPE_FIELD_TYPE (resolved_type, i), addr_stack, 0); TYPE_FIELD_TYPE (resolved_type, i) = t; - if (TYPE_LENGTH (t) > max_len) - max_len = TYPE_LENGTH (t); + + struct type *real_type = check_typedef (t); + if (TYPE_LENGTH (real_type) > max_len) + max_len = TYPE_LENGTH (real_type); } TYPE_LENGTH (resolved_type) = max_len; @@ -2103,8 +2105,12 @@ resolve_dynamic_struct (struct type *type, if (TYPE_FIELD_BITSIZE (resolved_type, i) != 0) new_bit_length += TYPE_FIELD_BITSIZE (resolved_type, i); else - new_bit_length += (TYPE_LENGTH (TYPE_FIELD_TYPE (resolved_type, i)) - * TARGET_CHAR_BIT); + { + struct type *real_type + = check_typedef (TYPE_FIELD_TYPE (resolved_type, i)); + + new_bit_length += (TYPE_LENGTH (real_type) * TARGET_CHAR_BIT); + } /* Normally, we would use the position and size of the last field to determine the size of the enclosing structure. But GCC seems diff --git a/gdb/testsuite/gdb.base/vla-datatypes.c b/gdb/testsuite/gdb.base/vla-datatypes.c index 4902282e16..b98fe0da90 100644 --- a/gdb/testsuite/gdb.base/vla-datatypes.c +++ b/gdb/testsuite/gdb.base/vla-datatypes.c @@ -46,11 +46,14 @@ vla_factory (int n) BAR bar_vla[n]; int i; - struct vla_struct + /* Define a typedef for a VLA structure. */ + typedef struct vla_struct { int something; int vla_field[n]; - } vla_struct_object; + } vla_struct_t; + + vla_struct_t vla_struct_object; struct inner_vla_struct { @@ -59,14 +62,33 @@ vla_factory (int n) int after; } inner_vla_struct_object; + /* Define a structure which uses a typedef for the VLA field + to make sure that GDB creates the proper type for this field, + preventing a possible assertion failure (see gdb/21356). */ + struct vla_struct_with_vla_typedef + { + int something; + vla_struct_t vla_object; + } vla_struct_with_vla_typedef_object; + union vla_union { int vla_field[n]; } vla_union_object; + /* Like vla_struct_with_vla_typedef but a union type. */ + union vla_union_with_vla_typedef + { + int something; + vla_struct_t vla_object; + } vla_union_with_vla_typedef_object; + vla_struct_object.something = n; inner_vla_struct_object.something = n; inner_vla_struct_object.after = n; + vla_struct_with_vla_typedef_object.something = n * 2; + vla_struct_with_vla_typedef_object.vla_object.something = n * 3; + vla_union_with_vla_typedef_object.vla_object.something = n * 3 + 1; for (i = 0; i < n; i++) { int_vla[i] = i*2; @@ -85,6 +107,8 @@ vla_factory (int n) vla_struct_object.vla_field[i] = i*2; vla_union_object.vla_field[i] = i*2; inner_vla_struct_object.vla_field[i] = i*2; + vla_struct_with_vla_typedef_object.vla_object.vla_field[i] = i * 3; + vla_union_with_vla_typedef_object.vla_object.vla_field[i] = i * 3 - 1; } size_t int_size = sizeof(int_vla); /* vlas_filled */ diff --git a/gdb/testsuite/gdb.base/vla-datatypes.exp b/gdb/testsuite/gdb.base/vla-datatypes.exp index d32ed5afce..e943c4aac9 100644 --- a/gdb/testsuite/gdb.base/vla-datatypes.exp +++ b/gdb/testsuite/gdb.base/vla-datatypes.exp @@ -57,6 +57,10 @@ gdb_test "print vla_struct_object" \ "\\\{something = 5, vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}" gdb_test "print vla_union_object" \ "\\\{vla_field = \\\{0, 2, 4, 6, 8\\\}\\\}" +gdb_test "print vla_struct_with_vla_typedef_object" \ + "\\\{something = 10, vla_object = \\\{something = 15, vla_field = \\\{0, 3, 6, 9, 12\\\}\\\}\\\}" +gdb_test "print vla_union_with_vla_typedef_object" \ + "\\\{something = 16, vla_object = \\\{something = 16, vla_field = \\\{-1, 2, 5, 8, 11\\\}\\\}\\\}" # Check whatis of VLA's. gdb_test "whatis int_vla" "type = int \\\[5\\\]" "whatis int_vla" @@ -78,7 +82,7 @@ gdb_test "whatis unsigned_char_vla" "type = unsigned char \\\[5\\\]" \ "whatis unsigned_char_vla" gdb_test "whatis foo_vla" "type = struct foo \\\[5\\\]" "whatis foo_vla" gdb_test "whatis bar_vla" "type = BAR \\\[5\\\]" "whatis bar_vla" -gdb_test "whatis vla_struct_object" "type = struct vla_struct" +gdb_test "whatis vla_struct_object" "type = vla_struct_t" gdb_test "whatis vla_union_object" "type = union vla_union" # Check ptype of VLA's.