From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id DAmRDms8ZWlkrz8AWB0awg (envelope-from ) for ; Mon, 12 Jan 2026 13:24:43 -0500 Authentication-Results: simark.ca; dkim=pass (2048-bit key; unprotected) header.d=polymtl.ca header.i=@polymtl.ca header.a=rsa-sha256 header.s=oct2025 header.b=rFBp38UX; dkim-atps=neutral Received: by simark.ca (Postfix, from userid 112) id 2EB1F1E08D; Mon, 12 Jan 2026 13:24:43 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-25) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=ARC_SIGNED,ARC_VALID,BAYES_00, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED,RCVD_IN_VALIDITY_CERTIFIED_BLOCKED, RCVD_IN_VALIDITY_RPBL_BLOCKED,RCVD_IN_VALIDITY_SAFE_BLOCKED autolearn=ham autolearn_force=no version=4.0.1 Received: from vm01.sourceware.org (vm01.sourceware.org [38.145.34.32]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 396611E08D for ; Mon, 12 Jan 2026 13:24:42 -0500 (EST) Received: from vm01.sourceware.org (localhost [127.0.0.1]) by sourceware.org (Postfix) with ESMTP id 95F5B4BA2E26 for ; Mon, 12 Jan 2026 18:24:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 95F5B4BA2E26 Authentication-Results: sourceware.org; dkim=pass (2048-bit key, unprotected) header.d=polymtl.ca header.i=@polymtl.ca header.a=rsa-sha256 header.s=oct2025 header.b=rFBp38UX Received: from smtp.polymtl.ca (smtp.polymtl.ca [132.207.4.11]) by sourceware.org (Postfix) with ESMTPS id CDA464BA2E1D for ; Mon, 12 Jan 2026 18:24:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org CDA464BA2E1D Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=polymtl.ca Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=polymtl.ca ARC-Filter: OpenARC Filter v1.0.0 sourceware.org CDA464BA2E1D Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=132.207.4.11 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1768242255; cv=none; b=OC0iE7Gs/W/q2nsiWF7EQ/V4Aki4TUiXaVssnMYK8HrSd6GkPgxPAZOD2YoiPB9KeCaZGIeWiCBAxcFWybxNB9hYHrGU25pOIGqGNxohzEsYYS2fkOXJ5Ejn7cTW+2vezUrs+rTyd6+osnqkXJylD7cyqPbIvSdQYs42K8ZnWts= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1768242255; c=relaxed/simple; bh=+95JwfaUxVsIm5tdu+817ZKi6S1kLrzYYBuprOODnz0=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=ZQdshcUN0gybZzonvFrnE+rq/TDiHz+Y7mjs0gRt8jYfOSa+7iVAdPBbeWjD9/9M8/ehMCPsd8SQLEf6oW1b6cgK+zKLZ6mS9CxMkumAjS9ovk+rQIZ9yP0I9IPjA4DgP1ZkSzuYHysmC6cQ+pYKSW/qsNnawqvbV2xelTu3+9c= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CDA464BA2E1D Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id 60CIO7oU158671 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Jan 2026 13:24:12 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.polymtl.ca 60CIO7oU158671 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=polymtl.ca; s=oct2025; t=1768242252; bh=c5OzB/DT7sOeS9uSdUAfRxFKDKNymcwju2HdJ3awn4w=; h=From:To:Cc:Subject:Date:From; b=rFBp38UXV92sj1vPKJCLS7syhcH8kCzToLpR9gG2nhJXQJghEK0dOSbADs5dEM9oL LLShQEHNI5DV1wPK+GVkuw0c+4BxqfDfDkduveu4+pQ1OFmdR6gE2+M8/GJ1Alo88w OsrabYbdig++8ckOIUL2+gg1VZB9I4xoOo5iVzJEHa3XoH2VRA60agD0HAhi9prn6S D5tBSBEUkwhjHohzSsIkF9DfqMr/kQJijoXVV/jt75BGDomQc0iKVZewdj0E+sSJWQ oCP4JU9digAC0uOls0hdtzlD/ZebXkkcMOfAjXRAiqVj9U5RaRgz9BiGrLTy7XwB9J FkZ1rcN3/Ww8g== Received: by simark.ca (Postfix) id B80621E08D; Mon, 12 Jan 2026 13:24:07 -0500 (EST) From: simon.marchi@polymtl.ca To: gdb-patches@sourceware.org Cc: Simon Marchi Subject: [PATCH] gdb, gdbsupport, gdbserver: add support for printf 't' length modifier Date: Mon, 12 Jan 2026 13:24:02 -0500 Message-ID: <20260112182407.622150-1-simon.marchi@polymtl.ca> X-Mailer: git-send-email 2.52.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Mon, 12 Jan 2026 18:24:07 +0000 X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces~public-inbox=simark.ca@sourceware.org From: Simon Marchi Tom de Vries reported [1] that a use of the `t` printf length modifier (used for ptrdiff_t) breaks "set debug dwarf-die 1": +break -qualified main Reading Reading compcomp unit at offset unit at offset 0x00x39 Reading comp unit at offset 0x1a8 Reading comp unit at offset 0x1e9 Reading comp unit at offset 0x2c5 Reading comp unit at offset 0x2a2 Reading comp unit at offset 0x904 Unrecognized format specifier 't' in printf This use is in dwarf2/read.c: gdb_printf (gdb_stdlog, "Read die from %s@0x%tx of %s:\n", m_die_section->get_name (), (begin_info_ptr - m_die_section->buffer), bfd_get_filename (m_abfd)); Add support for the `t` length modifier in format_pieces, which gdb_printf ultimately uses (through ui_out::vmessage). Modify the three users of format_pieces: gdb's printf command, gdb's ui_out::vmessage function and gdbserver's ax_printf function. The implementation is mostly copied from what we do for size_t. Since format_pieces is also used to implement the printf command, this patch brings user-visible changes. Before: (gdb) printf "%td\n", -123 ❌️ Unrecognized format specifier 't' in printf After: (gdb) printf "%td\n", -123 -123 [1] https://inbox.sourceware.org/gdb-patches/d4ccce34-aad5-4e3d-8fc9-efb2fc11275c@suse.de/ Change-Id: Ie9fce78f5f48082d8f8a9ca2847b5ae26acaa60d --- gdb/printcmd.c | 10 ++++++++++ gdb/testsuite/gdb.base/printcmds.c | 6 ++++++ gdb/testsuite/gdb.base/printcmds.exp | 4 ++++ gdb/ui-out.c | 18 ++++++++++++++++++ gdb/unittests/format_pieces-selftests.c | 12 ++++++++---- gdbserver/ax.cc | 8 ++++++++ gdbsupport/format.cc | 11 ++++++++++- gdbsupport/format.h | 2 +- 8 files changed, 65 insertions(+), 6 deletions(-) diff --git a/gdb/printcmd.c b/gdb/printcmd.c index 783b83615d02..7c97fc719926 100644 --- a/gdb/printcmd.c +++ b/gdb/printcmd.c @@ -2815,6 +2815,16 @@ ui_printf (const char *arg, struct ui_file *stream) { size_t val = value_as_long (val_args[i]); + DIAGNOSTIC_PUSH + DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL + gdb_printf (stream, current_substring, val); + DIAGNOSTIC_POP + break; + } + case ptrdiff_t_arg: + { + ptrdiff_t val = value_as_long (val_args[i]); + DIAGNOSTIC_PUSH DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL gdb_printf (stream, current_substring, val); diff --git a/gdb/testsuite/gdb.base/printcmds.c b/gdb/testsuite/gdb.base/printcmds.c index 8445fcc1aa2a..82796932e1d3 100644 --- a/gdb/testsuite/gdb.base/printcmds.c +++ b/gdb/testsuite/gdb.base/printcmds.c @@ -2,6 +2,8 @@ It is explicitly unsigned to avoid differences due to native characters being either signed or unsigned. */ #include +#include + unsigned char ctable1[256] = { 0000, 0001, 0002, 0003, 0004, 0005, 0006, 0007, 0010, 0011, 0012, 0013, 0014, 0015, 0016, 0017, @@ -77,6 +79,10 @@ charptr teststring2 = "more contents"; const char *teststring3 = "this is a longer test string that we can use"; +/* For testing printf with %z (size_t) and %t (ptrdiff_t) length modifiers. */ +size_t test_size = 1234; +ptrdiff_t test_ptrdiff = -5678; + /* Test printing of a struct containing character arrays. */ struct some_arrays { diff --git a/gdb/testsuite/gdb.base/printcmds.exp b/gdb/testsuite/gdb.base/printcmds.exp index bc100f93df9a..32a952f01a55 100644 --- a/gdb/testsuite/gdb.base/printcmds.exp +++ b/gdb/testsuite/gdb.base/printcmds.exp @@ -908,6 +908,10 @@ proc test_printf {} { # PR cli/14977. gdb_test "printf \"%s\\n\", 0" "\\(null\\)" + # Test %z (size_t) and %t (ptrdiff_t) length modifiers. + gdb_test "printf \"%zu\\n\", test_size" "1234" + gdb_test "printf \"%td\\n\", test_ptrdiff" "-5678" + with_max_value_size 20 { gdb_test {printf "%s", teststring3} \ "^printed string requires 45 bytes, which is more than max-value-size" diff --git a/gdb/ui-out.c b/gdb/ui-out.c index 4f20e6b93477..87874e22530f 100644 --- a/gdb/ui-out.c +++ b/gdb/ui-out.c @@ -682,6 +682,24 @@ ui_out::vmessage (const ui_file_style &in_style, const char *format, } } break; + case ptrdiff_t_arg: + { + ptrdiff_t val = va_arg (args, ptrdiff_t); + switch (piece.n_int_args) + { + case 0: + call_do_message (style, current_substring, val); + break; + case 1: + call_do_message (style, current_substring, intvals[0], val); + break; + case 2: + call_do_message (style, current_substring, + intvals[0], intvals[1], val); + break; + } + } + break; case double_arg: call_do_message (style, current_substring, va_arg (args, double)); break; diff --git a/gdb/unittests/format_pieces-selftests.c b/gdb/unittests/format_pieces-selftests.c index af574ccc900f..c5f3cf74f1dc 100644 --- a/gdb/unittests/format_pieces-selftests.c +++ b/gdb/unittests/format_pieces-selftests.c @@ -105,40 +105,44 @@ test_gdb_formats () static void test_format_int_sizes () { - check ("Hello\\t %hu%lu%llu%zu", /* ARI: %ll */ + check ("Hello\\t %hu%lu%llu%zu%tu", /* ARI: %ll */ { {"Hello\t ", literal_piece, 0}, {"%hu", int_arg, 0}, {"%lu", long_arg, 0}, {"%" LL "u", long_long_arg, 0}, {"%zu", size_t_arg, 0}, + {"%tu", ptrdiff_t_arg, 0}, }); - check ("Hello\\t %hx%lx%llx%zx", /* ARI: %ll */ + check ("Hello\\t %hx%lx%llx%zx%tx", /* ARI: %ll */ { {"Hello\t ", literal_piece, 0}, {"%hx", int_arg, 0}, {"%lx", long_arg, 0}, {"%" LL "x", long_long_arg, 0}, {"%zx", size_t_arg, 0}, + {"%tx", ptrdiff_t_arg, 0}, }); - check ("Hello\\t %ho%lo%llo%zo", /* ARI: %ll */ + check ("Hello\\t %ho%lo%llo%zo%to", /* ARI: %ll */ { {"Hello\t ", literal_piece, 0}, {"%ho", int_arg, 0}, {"%lo", long_arg, 0}, {"%" LL "o", long_long_arg, 0}, {"%zo", size_t_arg, 0}, + {"%to", ptrdiff_t_arg, 0}, }); - check ("Hello\\t %hd%ld%lld%zd", /* ARI: %ll */ + check ("Hello\\t %hd%ld%lld%zd%td", /* ARI: %ll */ { {"Hello\t ", literal_piece, 0}, {"%hd", int_arg, 0}, {"%ld", long_arg, 0}, {"%" LL "d", long_long_arg, 0}, {"%zd", size_t_arg, 0}, + {"%td", ptrdiff_t_arg, 0}, }); } diff --git a/gdbserver/ax.cc b/gdbserver/ax.cc index 44fcf3157291..4993bed2532c 100644 --- a/gdbserver/ax.cc +++ b/gdbserver/ax.cc @@ -908,6 +908,14 @@ ax_printf (CORE_ADDR fn, CORE_ADDR chan, const char *format, break; } + case ptrdiff_t_arg: + { + ptrdiff_t val = args[i]; + + printf (current_substring, val); + break; + } + case literal_piece: /* Print a portion of the format string that has no directives. Note that this will not include any diff --git a/gdbsupport/format.cc b/gdbsupport/format.cc index b515a95114e0..43995edf453e 100644 --- a/gdbsupport/format.cc +++ b/gdbsupport/format.cc @@ -111,6 +111,7 @@ format_pieces::format_pieces (const char **arg, bool gdb_extensions, int seen_big_l = 0, seen_h = 0, seen_big_h = 0; int seen_big_d = 0, seen_double_big_d = 0; int seen_size_t = 0; + int seen_ptrdiff_t = 0; int bad = 0; int n_int_args = 0; bool seen_i64 = false; @@ -224,6 +225,11 @@ format_pieces::format_pieces (const char **arg, bool gdb_extensions, seen_size_t = 1; f++; break; + case 't': + /* For ptrdiff_t. */ + seen_ptrdiff_t = 1; + f++; + break; case 'I': /* Support the Windows '%I64' extension, because an earlier call to format_pieces might have converted %lld @@ -257,6 +263,8 @@ format_pieces::format_pieces (const char **arg, bool gdb_extensions, case 'i': if (seen_size_t) this_argclass = size_t_arg; + else if (seen_ptrdiff_t) + this_argclass = ptrdiff_t_arg; else if (lcount == 0) this_argclass = int_arg; else if (lcount == 1) @@ -334,7 +342,8 @@ format_pieces::format_pieces (const char **arg, bool gdb_extensions, if (lcount > 1 || seen_h || seen_big_h || seen_big_h || seen_big_d || seen_double_big_d || seen_size_t - || seen_prec || seen_zero || seen_space || seen_plus) + || seen_ptrdiff_t || seen_prec || seen_zero || seen_space + || seen_plus) bad = 1; this_argclass = value_arg; diff --git a/gdbsupport/format.h b/gdbsupport/format.h index 91bcf1db55a6..ced10e46a716 100644 --- a/gdbsupport/format.h +++ b/gdbsupport/format.h @@ -36,7 +36,7 @@ enum argclass { literal_piece, - int_arg, long_arg, long_long_arg, size_t_arg, ptr_arg, + int_arg, long_arg, long_long_arg, size_t_arg, ptrdiff_t_arg, ptr_arg, string_arg, wide_string_arg, wide_char_arg, double_arg, long_double_arg, dec32float_arg, dec64float_arg, dec128float_arg, base-commit: b9517052ce5c1d87bfd7030bcbf90a98f63fddf6 -- 2.52.0