https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85400
Bug ID: 85400
Summary: R_SPARC_TLS_*: invalid relocations generated for
optimized builds on sparc
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: phantall at gmail dot com
Target Milestone: ---
In Solaris 10 & 11 using GCC versions 4.8, 4.9.2, 7.2.0 I get relocation errors
when thread_local variables are used in a struct/class. Example code that
reproduces the problem:
> struct Test {
> int blah( int y ) {
> thread_local mything = 3;
> mything = y > 0 ? y : mything;
> return mything;
> }
> };
> int stuff( Test& test, int y ) {
> return test.blah(y);
> }
When compiled:
> $ g++ -m32 -fPIC -std=gnu++14 blah.cc -c -o blah1.o
> $ g++ -m32 -fPIC -std=gnu++14 blah.cc -c -o blah2.o -O3
> $ objdump -xC blah1.o | grep mything
> (...)
> 00000038 R_SPARC_TLS_GD_HI22 Test::blah(int)::mything
> 0000003c R_SPARC_TLS_GD_LO10 Test::blah(int)::mything
> (...)
> $ objdump -xC blah2.o | grep mything
> (...)
> 00000014 R_SPARC_TLS_LDM_HI22 Test::blah(int)::mything
> 0000001c R_SPARC_TLS_LDO_HIX22 Test::blah(int)::mything
> 00000020 R_SPARC_TLS_LDM_LO10 Test::blah(int)::mything
> 00000024 R_SPARC_TLS_LDO_LOX10 Test::blah(int)::mything
> (...)
> $ g++ -m32 -fPIC -shared blah2.o -o libblah.so
> ld: fatal: relocation error: R_SPARC_TLS_LDM_HI22: file blah2.o: symbol:
> _ZZN4Test4blahEiE7mything: bound to: blah.o: relocation illegal when not
> bound to object being created
> ld: fatal: relocation error: R_SPARC_TLS_LDM_HIX22: file blah2.o: symbol:
> _ZZN4Test4blahEiE7mything: bound to: blah.o: relocation illegal when not
> bound to object being created
> ...
For reference:
* It happens at all optimization levels above -O0 and for all combinations of
-std={c,gnu}++{11,14}
* This was discovered while building boost 1.66.0 with -std=gnu++14. The error
occurs while linking libboost_fiber.so and comes from work_stealing.cpp for
boost::fibers::detail::spinlock_ttas::lock()::generator ... where "generator"
in that code is a static thread_local at member-function scope.
* The compilers I built and those produced by OpenCSW use the Solaris assembler
(/usr/ccs/bin/as) instead of gas.
