Compile this trivial program
---------
#include <iostream>
#include <fstream>
int main() {
std::ifstream fin("t3.cpp");
}
---------
with
g++ -g -O2 -Wall -pthread t3.cpp
Running this program dumps core.
Leaving out the option -pthread it does not abort and works o.k.
Root cause seems to be that the std::ifstream class has different size with and
without -pthread (i.e. -DTHREAD_SAFE) since definition of ifstream member
std::__c_lock == __gthread_mutex_t is different with and without -pthread.
This is an AIX only symptom. __c_lock is an int without threads and posix_lock
with threads.
Since there is only one libstdc++ for both with and without threads weird
things will happen.
-- diagnosis program --
#include <fstream>
#include <iostream>
int main() {
printf( "%ld\n",sizeof( std::ifstream));
printf(" %ld\n", sizeof( __gthread_mutex_t));
}
----------------
Output with -pthread
296
52
--- without
248
4
------------
I would propose to compile gcc code always with THREAD_SAFE alway on.
--
Summary: ifstream broken
Product: gcc
Version: 4.4.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: o dot flebbe at science-computing dot de
GCC build triplet: powerpc-ibm-aix5.3.0.0
GCC host triplet: powerpc-ibm-aix5.3.0.0
GCC target triplet: powerpc-ibm-aix5.3.0.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42349
