https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90562
Bug ID: 90562
Summary: thread_local variables in inline functions have
different addresses across shared libraries
Product: gcc
Version: 7.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: tudorb at gmail dot com
Target Milestone: ---
This is reduced from production code.
I have an inline function (not "static inline", just "inline") that has a
thread_local variable. The thread_local variable has a different address in
different shared libraries.
Code is at https://github.com/tudor/gcc_tl_bug
The function is defined in a.h, and used in a.cc and b.cc. If all files are
linked together (as per "mkstatic"), the function has the same address (as per
the C++ standard), and so does the thread-local variable:
$ ./main-static
0x5583a6b1a790 0x7f9e5acee4fc
0x5583a6b1a790 0x7f9e5acee4fc
If a.cc and b.cc are compiled in the different shared libraries (as per
"mkshared"), the function still has the same address, but the thread-local
variable does not:
$ ./main-shared
0x7f501b1d87c0 0x7f501b5e673c
0x7f501b1d87c0 0x7f501b5e6738
This is gcc 7.4.0, Ubuntu 18.04, x86-64.
$ gcc --version
gcc (Ubuntu 7.4.0-1ubuntu1~18.04) 7.4.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
