From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29187 invoked by alias); 22 Feb 2003 00:06:01 -0000 Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-prs-owner@gcc.gnu.org Received: (qmail 29165 invoked by uid 71); 22 Feb 2003 00:06:01 -0000 Resent-Date: 22 Feb 2003 00:06:01 -0000 Resent-Message-ID: <20030222000601.29164.qmail@sources.redhat.com> Resent-From: gcc-gnats@gcc.gnu.org (GNATS Filer) Resent-Cc: gcc-prs@gcc.gnu.org, gcc-bugs@gcc.gnu.org Resent-Reply-To: gcc-gnats@gcc.gnu.org, raymond@cdlsystems.com Received: (qmail 24315 invoked by uid 48); 21 Feb 2003 23:58:51 -0000 Message-Id: <20030221235851.24314.qmail@sources.redhat.com> Date: Sat, 22 Feb 2003 00:06:00 -0000 From: raymond@cdlsystems.com Reply-To: raymond@cdlsystems.com To: gcc-gnats@gcc.gnu.org X-Send-Pr-Version: gnatsweb-2.9.3 (1.1.1.1.2.31) Subject: c++/9796: dynamic cast in shared library failed X-SW-Source: 2003-02/txt/msg01090.txt.bz2 List-Id: >Number: 9796 >Category: c++ >Synopsis: dynamic cast in shared library failed >Confidential: no >Severity: serious >Priority: medium >Responsible: unassigned >State: open >Class: sw-bug >Submitter-Id: net >Arrival-Date: Sat Feb 22 00:06:01 UTC 2003 >Closed-Date: >Last-Modified: >Originator: raymond@cdlsystems.com >Release: GCC 3.2 >Organization: >Environment: linux >Description: When a class is created in the main function and passing it off to a shared library for downcasting, dynamic cast returns null. typedef void ( *PFN )( Parent* ); int main() { Parent parent; Child child; void* pDl = dlopen ( "libshared.so", RTLD_GLOBAL|RTLD_NOW); PFN pfnAcquire = ( PFN )dlsym( pDl, "function1" ); printf( "before %x %x\n", &child, dynamic_cast( &child )); pfnAcquire( &child ); } In the acquired function from the shared library, if the same dynamic cast operation is done again, the result is always null. When compiling the so file, -Wl,-E is used. See the attached script >How-To-Repeat: use the provided script to recompile the program and run it. >Fix: >Release-Note: >Audit-Trail: >Unformatted: ----gnatsweb-attachment---- Content-Type: application/x-zip-compressed; name="dynamiccast.zip" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="dynamiccast.zip" UEsDBBQAAAAIAC+CVS7gQl6EgwAAAKsAAAAKAAAAc2hhcmVkLmN4eE2NQQrCMBRE9/8UQ0RISxFc K256gR5AkJCk9kP7I+mvVMS7SxDF2c3wHrNh8eMSIoxP05RkNxiiuGrMAtMauicO6Bfxykn2Fp3L UbSGunyNioqeBOCWWbS3MCyYE7YrvJs1BmgpZzENCvbNR27+p/AQN7G/FO/YDjyG+mR/L9WBXvQG UEsDBBQAAAAIAMuCVS6vh+4RlQAAADUBAAAIAAAAY29tbW9uLmiVjjEOwjAMRXef4qss7cIBCmLh AhyAJSRBtWSlVZN2qdqz04QKAkx4sOT/7e+3Y6dlMBZHHwy3++ZEpEV5j4vqrQs0UTfchHVNwKaV Fab5EOeR+zAowfJt5ObYskGwfrWjPMW2VtezC/cSRZduoZWINVdXoEoRM61RG8u5YTGo8UR5oyFj Szs/aMuH/g+WTj9fVDnUA1BLAwQUAAAACAA3g1UucIa+QhIBAAC2AQAACAAAAG1haW4uY3h4VVBd S8MwFH3Pr7hkTJJSij7XCdOhL2UbIvgijC4fNJAmNUnFovvvJlnZEEJyOeeee87NQhmmRy4AM9v3 1lQdRosLxrVkGUIoTIPgQsKXVRwIFPvnLVAC+9YJEwqgNULKBOhbZQhFPwhg5mDIT52Qc1kF4QNJ igg9dUpzYOnOLbn615EcCxg2GlbAtR2Eif5Yq6Pv4jheeYtLeH1rNoeXZve4bn5zvd29z3olyVm9 glugCcnpUhwXI0cWL30cwbVwzjpC0zKRPeUd4pqDNGv2OSonYgKSIcq1n/o8twQsR8OCsuYOw+x5 mXwU0kbd8jueDxNdbvKCJQCfTNsrdmCtD/f5F4oHMtNAzxGuzlemRif0B1BLAwQUAAAACAAzh1Uu Li7jbD0AAABQAAAABAAAAGMuc2hL19ZW0E1X0M1XyE3MzAMTeskVFQq6OSk5XOlQyeKMxKLUFAXd 8BwdXVcFkOKczCSIoF5xvgKUBdTGxQUAUEsBAhQAFAAAAAgAL4JVLuBCXoSDAAAAqwAAAAoAAAAA AAAAAQAAALaBAAAAAHNoYXJlZC5jeHhQSwECFAAUAAAACADLglUur4fuEZUAAAA1AQAACAAAAAAA AAABAAAAtoGrAAAAY29tbW9uLmhQSwECFAAUAAAACAA3g1UucIa+QhIBAAC2AQAACAAAAAAAAAAB AAAAtoFmAQAAbWFpbi5jeHhQSwECFAAUAAAACAAzh1UuLi7jbD0AAABQAAAABAAAAAAAAAABAAAA toGeAgAAYy5zaFBLBQYAAAAABAAEANYAAAD9AgAAAAA=