| Summary: | [3.4 Regression] Segmentation fault in ios_base::sync_with_stdio | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Pétur Runólfsson <peturrun> |
| Component: | libstdc++ | Assignee: | Paolo Carlini <paolo.carlini> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | gcc-bugs |
| Priority: | P2 | ||
| Version: | 3.4.1 | ||
| Target Milestone: | 3.4.2 | ||
| Host: | i686-pc-linux-gnu | Target: | i686-pc-linux-gnu |
| Build: | i686-pc-linux-gnu | Known to work: | |
| Known to fail: | Last reconfirmed: | 2004-08-10 20:55:19 | |
| Attachments: | Test case | ||
Created attachment 6910 [details]
Test case
This works fine with 3.2.3 and 3.3.4, but segfaults with 3.4.1 and 3.5.
Thanks, Pétur. Subject: Bug 16959 CVSROOT: /cvs/gcc Module name: gcc Changes by: paolo@gcc.gnu.org 2004-08-11 09:31:13 Modified files: libstdc++-v3 : ChangeLog libstdc++-v3/src: ios_init.cc Added files: libstdc++-v3/testsuite/27_io/ios_base/sync_with_stdio: 16959.cc Log message: 2004-08-11 Paolo Carlini <pcarlini@suse.de> Petur Runolfsson <peturr02@ru.is> PR libstdc++/16959 * src/ios_init.cc (ios_base::sync_with_stdio): Make sure the standard streams are constructed. * testsuite/27_io/ios_base/sync_with_stdio/16959.cc: New. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&r1=1.2603&r2=1.2604 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/ios_init.cc.diff?cvsroot=gcc&r1=1.6&r2=1.7 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/27_io/ios_base/sync_with_stdio/16959.cc.diff?cvsroot=gcc&r1=NONE&r2=1.1 Subject: Bug 16959 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_4-branch Changes by: paolo@gcc.gnu.org 2004-08-12 09:11:08 Modified files: libstdc++-v3 : ChangeLog libstdc++-v3/src: ios_init.cc Added files: libstdc++-v3/testsuite/27_io/ios_base/sync_with_stdio: 16959.cc Log message: 2004-08-12 Paolo Carlini <pcarlini@suse.de> Petur Runolfsson <peturr02@ru.is> PR libstdc++/16959 * src/ios_init.cc (ios_base::sync_with_stdio): Make sure the standard streams are constructed. * testsuite/27_io/ios_base/sync_with_stdio/16959.cc: New. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.2224.2.151&r2=1.2224.2.152 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/ios_init.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.4.4.1&r2=1.4.4.2 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/27_io/ios_base/sync_with_stdio/16959.cc.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1 Fixed for mainline and 3.4.2. |
In src/ios_init.cc: bool ios_base::sync_with_stdio(bool __sync) { // _GLIBCXX_RESOLVE_LIB_DEFECTS // 49. Underspecification of ios_base::sync_with_stdio bool __ret = ios_base::Init::_S_synced_with_stdio; // Turn off sync with C FILE* for cin, cout, cerr, clog iff // currently synchronized. if (!__sync && __ret) { ios_base::Init::_S_synced_with_stdio = __sync; // Explicitly call dtors to free any memory that is // dynamically allocated by filebuf ctor or member functions, // but don't deallocate all memory by calling operator delete. buf_cout_sync.~stdio_sync_filebuf<char>(); buf_cin_sync.~stdio_sync_filebuf<char>(); buf_cerr_sync.~stdio_sync_filebuf<char>(); This is fine, except that there is no guarantee that buf_cout_sync and friends have been constructed before this gets run. If the objects haven't been constructed, the program segfaults. A simple fix would be to construct an ios_base::Init object at the beginning of the block.