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GET /api/1.1/patches/2229745/?format=api
{ "id": 2229745, "url": "http://patchwork.ozlabs.org/api/1.1/patches/2229745/?format=api", "web_url": "http://patchwork.ozlabs.org/project/gcc/patch/20260428165450.28555-2-peter0x44@disroot.org/", "project": { "id": 17, "url": "http://patchwork.ozlabs.org/api/1.1/projects/17/?format=api", "name": "GNU Compiler Collection", "link_name": "gcc", "list_id": "gcc-patches.gcc.gnu.org", "list_email": "gcc-patches@gcc.gnu.org", "web_url": null, "scm_url": null, "webscm_url": null }, "msgid": "<20260428165450.28555-2-peter0x44@disroot.org>", "date": "2026-04-28T16:54:50", "name": "[v2] c++: Improve -fdump-lang-class output", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "22fbd28418a2f34a7f425d987403c1d6bb87bbc8", "submitter": { "id": 88243, "url": "http://patchwork.ozlabs.org/api/1.1/people/88243/?format=api", "name": "Peter Damianov", "email": "peter0x44@disroot.org" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/gcc/patch/20260428165450.28555-2-peter0x44@disroot.org/mbox/", "series": [ { "id": 501904, "url": "http://patchwork.ozlabs.org/api/1.1/series/501904/?format=api", "web_url": "http://patchwork.ozlabs.org/project/gcc/list/?series=501904", "date": "2026-04-28T16:54:50", "name": "[v2] c++: Improve -fdump-lang-class output", "version": 2, "mbox": "http://patchwork.ozlabs.org/series/501904/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2229745/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2229745/checks/", "tags": {}, "headers": { "Return-Path": "<gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "gcc-patches@gcc.gnu.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "gcc-patches@gcc.gnu.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n secure) header.d=disroot.org header.i=@disroot.org header.a=rsa-sha256\n header.s=mail header.b=YTSDL6te;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=38.145.34.32; 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Tue, 28 Apr 2026 16:56:51 +0000 (GMT)", "from layka.disroot.org (layka.disroot.org [178.21.23.139])\n by sourceware.org (Postfix) with ESMTPS id 0372D4BA7980\n for <gcc-patches@gcc.gnu.org>; Tue, 28 Apr 2026 16:56:28 +0000 (GMT)", "from mail01.disroot.lan (localhost [127.0.0.1])\n by disroot.org (Postfix) with ESMTP id 1716B26F9D;\n Tue, 28 Apr 2026 18:56:28 +0200 (CEST)", "from layka.disroot.org ([127.0.0.1])\n by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP\n id BMhrX95FvF4h; Tue, 28 Apr 2026 18:56:26 +0200 (CEST)" ], "DKIM-Filter": [ "OpenDKIM Filter v2.11.0 sourceware.org EF5D74B920D7", "OpenDKIM Filter v2.11.0 sourceware.org 0372D4BA7980" ], "DMARC-Filter": "OpenDMARC Filter v1.4.2 sourceware.org 0372D4BA7980", "ARC-Filter": "OpenARC Filter v1.0.0 sourceware.org 0372D4BA7980", "ARC-Seal": "i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1777395389; cv=none;\n b=u5wA+SgW4dPziVevvtRyuvliHF0vmHCC929u46BYccZVeNq9k2lKm1WF7yKsAnx1Iu9UJcRqDLJ6fuwy5jLbwvxz+iY27WxzD/X6yCRPN+ojLNp44iXLMr5Zm2gLi1+JQi9h9nk2aeRgBMFkwr4tuX/jl6oTtMT9aFT8R4ohD8k=", "ARC-Message-Signature": "i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1777395389; c=relaxed/simple;\n bh=EVKM3UYBJwMD05Pkzy4lBgtCNzryEAdbdFUt5TmyW8E=;\n h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version;\n b=RC57QIQXUTsv0HTcqqDpr5VKl02ZVlLwf3obHSVtwYzrddM51+Ywu5jjC2N4Y3i8Ko8QRvo1iW0rOz0igUL39257FTYFeaoD+LBmfnyWnKGbutBUlXT4gFXrcoLDyXXVXeE/F2RrGt/6NRB6amEzdy93q6Rv9FGFyzCgMffZ4Xc=", "ARC-Authentication-Results": "i=1; server2.sourceware.org", "X-Virus-Scanned": "SPAM Filter at disroot.org", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=disroot.org; s=mail;\n t=1777395386; bh=EVKM3UYBJwMD05Pkzy4lBgtCNzryEAdbdFUt5TmyW8E=;\n h=From:To:Cc:Subject:Date;\n b=YTSDL6teK8cahQvQ3pP9JjRkYJ7RhYrxERE6bVPerwAtaXSYQZxL0vAAsPUe+UF6o\n zRhJTynRax7/kO4HTMyAVOLFRdirSXiq8vhlJkxLb7Wvu9XLngkdsZLDPT+78eP2Tg\n 3zfYAYMFQeKB8+dP5Ts2NR0r7DI5srX+XWoyY8f0PeNOavSobvR8uIe4NTyifG4ib4\n +i7GcbtXAJYps+tuoiOECOKzQdzeDKmeaEY7xbxKLziqd4SXJ05SqSuWomtZHJUPgq\n +OWZ1klCz3LRIJDoe4PEzWq0FZTGL3tfzMWXb+0zBXAbJAwhBjsIBdF6/oaIDLu9ks\n S4L/L+cDFqk4A==", "From": "Peter Damianov <peter0x44@disroot.org>", "To": "gcc-patches@gcc.gnu.org", "Cc": "Marek Polacek <polakec@redhat.com>, Peter Damianov <peter0x44@disroot.org>", "Subject": "[PATCH v2] c++: Improve -fdump-lang-class output", "Date": "Tue, 28 Apr 2026 17:54:50 +0100", "Message-ID": "<20260428165450.28555-2-peter0x44@disroot.org>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "gcc-patches@gcc.gnu.org", "X-Mailman-Version": "2.1.30", "Precedence": "list", "List-Id": "Gcc-patches mailing list <gcc-patches.gcc.gnu.org>", "List-Unsubscribe": "<https://gcc.gnu.org/mailman/options/gcc-patches>,\n <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>", "List-Archive": "<https://gcc.gnu.org/pipermail/gcc-patches/>", "List-Post": "<mailto:gcc-patches@gcc.gnu.org>", "List-Help": "<mailto:gcc-patches-request@gcc.gnu.org?subject=help>", "List-Subscribe": "<https://gcc.gnu.org/mailman/listinfo/gcc-patches>,\n <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>", "Errors-To": "gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org" }, "content": "When I was researching to write my blogpost about vtables:\nhttps://peter0x44.github.io/posts/vtables-itanium-abi/\n\nI noticed a few improvements I could make to -fdump-lang-class's output\n\n-fdump-lang-class prepended \"0x\" to HOST_WIDE_INT_PRINT_HEX outputs, but the\nmacro already includes that prefix, producing \"0x0x...\" in dumps.\n\nSome vtable entries hold signed values e.g. vcall offsets, vbase offsets,\n offset-to-top. When expr_as_string prints those INTEGER_CSTs,\nnegative offsets appear as large (unsigned) values. Print integer vtable\nentries as signed values, and keep expr_as_string for all other entries.\n\ngcc/cp/ChangeLog:\n\n\t* class.cc (dump_vtable_entry): New function.\n\t(dump_array): Use it.\n\t(dump_class_hierarchy_r): Drop redundant literal 0x from\n\tHOST_WIDE_INT_PRINT_HEX formatting.\n\t(dump_vtable): Likewise.\n\nSigned-off-by: Peter Damianov <peter0x44@disroot.org>\n---\n\nv2: add comment to dump_vtable_entry\nuse STRIP_NOPS\nsimplify code using print_decs instead of print_dec with SIGNED\n\n gcc/cp/class.cc | 31 ++++++++++++++++++++++++++-----\n 1 file changed, 26 insertions(+), 5 deletions(-)", "diff": "diff --git a/gcc/cp/class.cc b/gcc/cp/class.cc\nindex 8beeb797a08..4d2284b1891 100644\n--- a/gcc/cp/class.cc\n+++ b/gcc/cp/class.cc\n@@ -167,6 +167,7 @@ static int maybe_indent_hierarchy (FILE *, int, int);\n static tree dump_class_hierarchy_r (FILE *, dump_flags_t, tree, tree, int);\n static void dump_class_hierarchy (tree);\n static void dump_class_hierarchy_1 (FILE *, dump_flags_t, tree);\n+static void dump_vtable_entry (FILE *, tree);\n static void dump_array (FILE *, tree);\n static void dump_vtable (tree, tree, tree);\n static void dump_vtt (tree, tree);\n@@ -9729,7 +9730,7 @@ dump_class_hierarchy_r (FILE *stream,\n tree base_binfo;\n int i;\n \n- fprintf (stream, \"%s (0x\" HOST_WIDE_INT_PRINT_HEX \") \",\n+ fprintf (stream, \"%s (\" HOST_WIDE_INT_PRINT_HEX \") \",\n \t type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),\n \t (HOST_WIDE_INT) (uintptr_t) binfo);\n if (binfo != igo)\n@@ -9752,7 +9753,7 @@ dump_class_hierarchy_r (FILE *stream,\n if (BINFO_PRIMARY_P (binfo))\n {\n indented = maybe_indent_hierarchy (stream, indent + 3, indented);\n- fprintf (stream, \" primary-for %s (0x\" HOST_WIDE_INT_PRINT_HEX \")\",\n+ fprintf (stream, \" primary-for %s (\" HOST_WIDE_INT_PRINT_HEX \")\",\n \t type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),\n \t\t\t TFF_PLAIN_IDENTIFIER),\n \t (HOST_WIDE_INT) (uintptr_t) BINFO_INHERITANCE_CHAIN (binfo));\n@@ -9845,6 +9846,23 @@ dump_class_hierarchy (tree t)\n }\n }\n \n+/* Dump VALUE, a vtable entry, to STREAM. Print integer offsets as signed\n+ values. */\n+\n+static void\n+dump_vtable_entry (FILE *stream, tree value)\n+{\n+ /* Vtable offset entries are stored in the pointer-sized vtable entry\n+ type, but should be displayed as signed ptrdiff_t values. */\n+ tree cst = value;\n+ STRIP_NOPS (cst);\n+\n+ if (TREE_CODE (cst) == INTEGER_CST)\n+ print_decs (wi::to_wide (cst), stream);\n+ else\n+ fprintf (stream, \"%s\", expr_as_string (value, TFF_PLAIN_IDENTIFIER));\n+}\n+\n static void\n dump_array (FILE * stream, tree decl)\n {\n@@ -9863,8 +9881,11 @@ dump_array (FILE * stream, tree decl)\n \n FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),\n \t\t\t ix, value)\n- fprintf (stream, \"%-4ld %s\\n\", (long)(ix * elt),\n-\t expr_as_string (value, TFF_PLAIN_IDENTIFIER));\n+ {\n+ fprintf (stream, \"%-4ld \", (long)(ix * elt));\n+ dump_vtable_entry (stream, value);\n+ fprintf (stream, \"\\n\");\n+ }\n }\n \n static void\n@@ -9886,7 +9907,7 @@ dump_vtable (tree t, tree binfo, tree vtable)\n if (ctor_vtbl_p)\n \t{\n \t if (!BINFO_VIRTUAL_P (binfo))\n-\t fprintf (stream, \" (0x\" HOST_WIDE_INT_PRINT_HEX \" instance)\",\n+\t fprintf (stream, \" (\" HOST_WIDE_INT_PRINT_HEX \" instance)\",\n \t\t (HOST_WIDE_INT) (uintptr_t) binfo);\n \t fprintf (stream, \" in %s\", type_as_string (t, TFF_PLAIN_IDENTIFIER));\n \t}\n", "prefixes": [ "v2" ] }