From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22567 invoked by alias); 9 Jan 2008 17:15:49 -0000 Received: (qmail 22556 invoked by uid 22791); 9 Jan 2008 17:15:48 -0000 X-Spam-Check-By: sourceware.org Received: from igw3.br.ibm.com (HELO igw3.br.ibm.com) (32.104.18.26) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 09 Jan 2008 17:15:19 +0000 Received: from mailhub1.br.ibm.com (unknown [9.18.232.109]) by igw3.br.ibm.com (Postfix) with ESMTP id 19D1B3901D9 for ; Wed, 9 Jan 2008 15:07:25 -0200 (BRDT) Received: from d24av01.br.ibm.com (d24av01.br.ibm.com [9.18.232.46]) by mailhub1.br.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m09HFC0d3137618 for ; Wed, 9 Jan 2008 15:15:13 -0200 Received: from d24av01.br.ibm.com (loopback [127.0.0.1]) by d24av01.br.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m09HFBbp005570 for ; Wed, 9 Jan 2008 15:15:12 -0200 Received: from [9.18.238.251] ([9.18.238.251]) by d24av01.br.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id m09HFBC7005564; Wed, 9 Jan 2008 15:15:11 -0200 Subject: [libiberty] don't demangle functions named "." From: Thiago Jung Bauermann To: gcc-patches Cc: gdb-patches Content-Type: multipart/mixed; boundary="=-wE78jEhBqV4JYt8n2YCO" Date: Wed, 09 Jan 2008 17:15:00 -0000 Message-Id: <1199898911.15225.48.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.12.2 X-IsSubscribed: yes 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 X-SW-Source: 2008-01/txt/msg00197.txt.bz2 --=-wE78jEhBqV4JYt8n2YCO Content-Type: text/plain Content-Transfer-Encoding: 7bit Content-length: 1888 Hi folks, This patch is to stop the C++ demangler from trying to demangle a symbol which is not a C++ mangled function. The problem is happening in Linux/ppc64 with symbols marking the start of function instructions in the text section, which begin with a dot. When the function name starts with __, it's symbol will be something like .__. If the demangler is able to derive a valid argument list from , it will find a demangled "function" called . with some random argument list. This is happening with several functions in glibc: .__frexpf -> .(float, long double,...)(long long, float *) .__flbf -> .(float, long, bool, float) .__ffs -> .(float, float, short) .__ffsll -> .(float, float, short, long, long) .__sleep -> .(short, long,...)(...)( *) .__execve -> .(...)(long long,...)(char, void,...) .__dup -> .(double, *__restrict) .__fixdfdi -> .(float, int, long long, double, float, double, int) .__fixsfdi -> .(float, int, long long, short, float, double, int) This is a problem in GDB, for instance when showing a backtrace which goes through these functions in glibc: (gdb) bt #0 0x000004000015edf8 in .__libc_nanosleep () from /lib64/tls/libc.so.6 #1 0x000004000015eb74 in . () from /lib64/tls/libc.so.6 #2 0x0000000010000784 in sleeping_thread (p=0x0) at libc-nanosleep.c:8 (gdb) info symbol 0x000004000015eb74 .(short, long,...)(...)( *) + 148 in section .text With the patch applied: (gdb) bt #0 0x000004000015edf8 in .__libc_nanosleep () from /lib64/tls/libc.so.6 #1 0x000004000015eb74 in .__sleep () from /lib64/tls/libc.so.6 #2 0x0000000010000784 in sleeping_thread (p=0x0) at libc-nanosleep.c:8 (gdb) info symbol 0x000004000015eb74 .__sleep + 148 in section .text All the libiberty and GDB tests related to demangling continue to pass. Is this ok? -- []'s Thiago Jung Bauermann Software Engineer IBM Linux Technology Center --=-wE78jEhBqV4JYt8n2YCO Content-Disposition: attachment; filename=demangle-fix.diff Content-Type: text/x-patch; name=demangle-fix.diff; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-length: 2703 2008-01-09 Thiago Jung Bauermann * cplus-dem.c (demangle_function_name): Changed to return value indicating if a name was correctly demangled. (iterate_demangle_function): Use demangle_function_name return value. Index: src-git.demangle-fix/libiberty/cplus-dem.c =================================================================== --- src-git.demangle-fix.orig/libiberty/cplus-dem.c 2008-01-08 15:48:12.000000000 -0200 +++ src-git.demangle-fix/libiberty/cplus-dem.c 2008-01-08 15:48:54.000000000 -0200 @@ -414,7 +414,7 @@ static int do_type (struct work_stuff *, static int do_arg (struct work_stuff *, const char **, string *); -static void +static int demangle_function_name (struct work_stuff *, const char **, string *, const char *); @@ -2493,10 +2493,7 @@ iterate_demangle_function (struct work_s "__"-sequence. This is the normal case. */ if (ARM_DEMANGLING || LUCID_DEMANGLING || HP_DEMANGLING || EDG_DEMANGLING || strstr (scan + 2, "__") == NULL) - { - demangle_function_name (work, mangled, declp, scan); - return 1; - } + return demangle_function_name (work, mangled, declp, scan); /* Save state so we can restart if the guess at the correct "__" was wrong. */ @@ -2513,10 +2510,12 @@ iterate_demangle_function (struct work_s while (scan[2]) { - demangle_function_name (work, mangled, declp, scan); - success = demangle_signature (work, mangled, declp); - if (success) - break; + if (demangle_function_name (work, mangled, declp, scan)) + { + success = demangle_signature (work, mangled, declp); + if (success) + break; + } /* Reset demangle state for the next round. */ *mangled = mangle_init; @@ -4421,7 +4420,9 @@ demangle_nested_args (struct work_stuff return result; } -static void +/* Returns 1 if a valid function name was found or 0 otherwise. */ + +static int demangle_function_name (struct work_stuff *work, const char **mangled, string *declp, const char *scan) { @@ -4461,13 +4462,13 @@ demangle_function_name (struct work_stuf { work -> constructor += 1; string_clear (declp); - return; + return 1; } else if (strcmp (declp -> b, "__dt") == 0) { work -> destructor += 1; string_clear (declp); - return; + return 1; } } @@ -4575,6 +4576,13 @@ demangle_function_name (struct work_stuf } } } + + /* If a function name was obtained but it's not valid, we were not + successful. */ + if (LEN_STRING (declp) == 1 && declp->b[0] == '.') + return 0; + else + return 1; } /* a mini string-handling package */ --=-wE78jEhBqV4JYt8n2YCO--