From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 90026 invoked by alias); 31 Oct 2019 17:57:38 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 90011 invoked by uid 89); 31 Oct 2019 17:57:37 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham version=3.3.1 spammy= X-HELO: mx1.osci.io Received: from polly.osci.io (HELO mx1.osci.io) (8.43.85.229) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 31 Oct 2019 17:57:36 +0000 Received: by mx1.osci.io (Postfix, from userid 994) id 8666C2047F; Thu, 31 Oct 2019 13:57:34 -0400 (EDT) Received: from gnutoolchain-gerrit.osci.io (gnutoolchain-gerrit.osci.io [IPv6:2620:52:3:1:5054:ff:fe06:16ca]) by mx1.osci.io (Postfix) with ESMTP id D0F6C20300; Thu, 31 Oct 2019 13:57:30 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by gnutoolchain-gerrit.osci.io (Postfix) with ESMTP id B0DE020AF6; Thu, 31 Oct 2019 13:57:30 -0400 (EDT) X-Gerrit-PatchSet: 2 Date: Thu, 31 Oct 2019 17:57:00 -0000 From: "Simon Marchi (Code Review)" To: Tankut Baris Aktemur , gdb-patches@sourceware.org Cc: Tom Tromey , Andrew Burgess Auto-Submitted: auto-generated X-Gerrit-MessageType: comment Subject: [review v2] gdb: recognize new DWARF attributes: defaulted, deleted, calling conv. X-Gerrit-Change-Id: I54192f363115b78ec7435a8563b73fcace420765 X-Gerrit-Change-Number: 135 X-Gerrit-ChangeURL: X-Gerrit-Commit: 03330b972ac659c265a2ac4bdf81a6363952ec06 In-Reply-To: References: X-Gerrit-Comment-Date: Thu, 31 Oct 2019 13:57:30 -0400 Reply-To: gnutoolchain-gerrit@osci.io MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Disposition: inline User-Agent: Gerrit/3.0.3-75-g9005159e5d Content-Type: text/plain; charset=UTF-8 Message-Id: <20191031175730.B0DE020AF6@gnutoolchain-gerrit.osci.io> X-SW-Source: 2019-10/txt/msg01180.txt.bz2 Simon Marchi has posted comments on this change. Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135 ...................................................................... Patch Set 2: (3 comments) Thanks for the update. Just two minor comments about the validation. https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135/2/gdb/dwarf2read.c File gdb/dwarf2read.c: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135/2/gdb/dwarf2read.c@15831 PS2, Line 15831: 15822 | is_valid_DW_AT_calling_convention (ULONGEST value) | ... 15826 | case DW_CC_normal: 15827 | case DW_CC_program: 15828 | case DW_CC_nocall: 15829 | case DW_CC_pass_by_reference: 15830 | case DW_CC_pass_by_value: 15831 > case DW_CC_lo_user: 15832 > case DW_CC_hi_user: 15833 | /* case DW_CC_GNU_renesas_sh: Duplicate of DW_CC_lo_user. */ 15834 | case DW_CC_GNU_borland_fastcall_i386: 15835 | /* case DW_CC_GDB_IBM_OpenCL: Duplicate of DW_CC_hi_user. */ 15836 | return true; 15837 | } I don' think we should include lo_user and hi_user in the switch, since they are not "real" values. They just indicate the range for vendor-specific values. DW_CC_GNU_renesas_sh and DW_CC_GDB_IBM_OpenCL are "real" values, so they should be included in the switch. In the end, the behavior will be the same, since as you noted, they are duplicates of lo_user and hi_user. https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135/2/gdb/dwarf2read.c@15928 PS2, Line 15928: 15857 | read_structure_type (struct die_info *die, struct dwarf2_cu *cu) | ... 15923 | TYPE_DECLARED_CLASS (type) = 1; 15924 | 15925 | /* Store the calling convention in the type if it's available in 15926 | the die. Otherwise the calling convention remains set to 15927 | the default value DW_CC_normal. */ 15928 > attr = dwarf2_attr (die, DW_AT_calling_convention, cu); 15929 | if (attr != nullptr 15930 | && is_valid_DW_AT_calling_convention (DW_UNSND (attr))) 15931 | { 15932 | ALLOCATE_CPLUS_STRUCT_TYPE (type); 15933 | TYPE_CPLUS_CALLING_CONVENTION (type) According to table 5.5 of DWARF5, the acceptable calling convention values for types are restricted to: - DW_CC_normal - DW_CC_pass_by_value - DW_CC_pass_by_reference So should we complain and reject the value if it's not one of those? The idea is that if a producer emits an unacceptable value by mistake, the issue is caught as early as possible rather than silently accepted. In the spot where we read DW_AT_calling_convention for subroutines, we could validate that the value is one of those listed in table 3.3: - DW_CC_normal - DW_CC_program - DW_CC_nocall ... plus the vendor-specific values that we support. So it might be simpler to do two functions, is_valid_DW_AT_calling_convention_for_types and is_valid_DW_AT_calling_convention_for_subprogram. Therefore, in this patch I suggest calling the new function "is_valid_DW_AT_calling_convention_for_types" to leave room to do the same thing for subprograms. https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135/1/gdb/gdbtypes.h File gdb/gdbtypes.h: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/135/1/gdb/gdbtypes.h@1144 PS1, Line 1144: 1137 | struct func_type | ... 1139 | /* * The calling convention for targets supporting multiple ABIs. 1140 | Right now this is only fetched from the Dwarf-2 1141 | DW_AT_calling_convention attribute. The value is one of the 1142 | DW_CC enum dwarf_calling_convention constants. */ 1143 | 1144 > unsigned calling_convention : 8; 1145 | 1146 | /* * Whether this function normally returns to its caller. It is 1147 | set from the DW_AT_noreturn attribute if set on the 1148 | DW_TAG_subprogram. */ 1149 | > This is an existing definition I had aimed to be consistent with. Ack, let's change it in another patch. -- Gerrit-Project: binutils-gdb Gerrit-Branch: master Gerrit-Change-Id: I54192f363115b78ec7435a8563b73fcace420765 Gerrit-Change-Number: 135 Gerrit-PatchSet: 2 Gerrit-Owner: Tankut Baris Aktemur Gerrit-Reviewer: Andrew Burgess Gerrit-Reviewer: Tankut Baris Aktemur Gerrit-CC: Simon Marchi Gerrit-CC: Tom Tromey Gerrit-Comment-Date: Thu, 31 Oct 2019 17:57:30 +0000 Gerrit-HasComments: Yes Gerrit-Has-Labels: No Comment-In-Reply-To: Tankut Baris Aktemur Gerrit-MessageType: comment