Bug 2119380
| Summary: | binutils not working correctly with "clang -flto" | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Jesus Checa <jchecahi> | |
| Component: | binutils | Assignee: | Nick Clifton <nickc> | |
| binutils sub component: | system-version | QA Contact: | Miloš Prchlík <mprchlik> | |
| Status: | CLOSED ERRATA | Docs Contact: | Jacob Taylor Valdez <jvaldez> | |
| Severity: | unspecified | |||
| Priority: | unspecified | CC: | fweimer, mprchlik, nickc, ohudlick, sipoyare | |
| Version: | 8.7 | Keywords: | Bugfix, Triaged | |
| Target Milestone: | rc | |||
| Target Release: | --- | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | binutils-2.30-119.el8 | Doc Type: | No Doc Update | |
| Doc Text: | Story Points: | --- | ||
| Clone Of: | ||||
| : | 2119383 2120959 (view as bug list) | Environment: | ||
| Last Closed: | 2023-05-16 08:45:00 UTC | Type: | Bug | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 2119383, 2120959 | |||
Right - I have found the problem. There is a bug in the BFD library. It does automatically load a plugin when needed, but it looks in the wrong place for it: # strace nm foo.o |& grep plugin openat(AT_FDCWD, "/usr/bin/../bin/../lib/bfd-plugins", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 ENOENT (No such file or directory) The LLVMgold.so plugin is in the /usr/lib64/bfd-plugins directory not the /usr/lib/bfd-plugins directory. Fixed in binutils-2.30-119.el8 [root@ci-vm-10-0-139-112 ~]# rpm -q binutils
binutils-2.30-119.el8.x86_64
[root@ci-vm-10-0-139-112 ~]# echo "void lto_function(){}" | clang -flto -O2 -c -x c -o foo.o -
[root@ci-vm-10-0-139-112 ~]# nm foo.o
00000000 T lto_function
[root@ci-vm-10-0-139-112 ~]# ar crs foo.a foo.o
[root@ci-vm-10-0-139-112 ~]# readelf -c foo.a
Index of archive foo.a: (1 entries, 0xe bytes in the symbol table)
Contents of binary foo.a(foo.o) at offset 0x5a
lto_function
[root@ci-vm-10-0-139-112 ~]#
Verified with binutils-2.30-119.el8 Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (binutils bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2023:2949 |
Description of problem: binutils are not able to correctly read objects and binaries compiled with "clang -flto". I tested this in RHEL-9.0 and Fedora 34+. In those environments the output is as expected. This is reproducible in every supported arch. How reproducible: 100% Steps to Reproduce: 1. echo "void lto_function(){}" | clang -flto -O2 -c -x c -o foo.o - 2. nm foo.o 3. ar crs foo.a foo.o 4. readelf -c foo.a Actual results: [root@hpe-apollo-cn99xx-14-vm-25 ~]# echo "void lto_function(){}" | clang -flto -O2 -c -x c -o foo.o - [root@hpe-apollo-cn99xx-14-vm-25 ~]# nm foo.o nm: foo.o: file format not recognized [root@hpe-apollo-cn99xx-14-vm-25 ~]# ar crs foo.a foo.o [root@hpe-apollo-cn99xx-14-vm-25 ~]# readelf -c foo.a foo.a has no archive index readelf: foo.a: Error: foo.a: unable to dump the index as none was found Expected results: $ echo "void lto_function(){}" | clang -flto -O2 -c -x c -o foo.o - $ nm foo.o 00000000 T lto_function $ ranlib foo.a foo.o ranlib: foo.o: file format not recognized $ ar crs foo.a foo.o $ readelf -c foo.a Index of archive foo.a: (1 entries, 0xe bytes in the symbol table) Contents of binary foo.a(foo.o) at offset 0x5a lto_function