| Summary: | g++ <string> defines BIG_ENDIAN | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Anders Munch <ajm> | ||||
| Component: | gcc | Assignee: | Jakub Jelinek <jakub> | ||||
| Status: | CLOSED WONTFIX | QA Contact: | qe-baseos-tools-bugs | ||||
| Severity: | low | Docs Contact: | |||||
| Priority: | unspecified | ||||||
| Version: | 7.2 | CC: | jwakely, mpolacek, ohudlick | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | All | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2016-02-16 08:52:07 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: | |||||
| Attachments: |
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The C++ compiler indeed predefines _GNU_SOURCE macro, because libstdc++ headers need various functions from that namespace. This is a known bug, but is not going to be fixed at least until GCC 7, and requires some heavy coordination between glibc and gcc. See e.g. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51749 Even after this is fixed upstream, this is not backportable to the RHEL 7 compiler and glibc. |
Created attachment 1127526 [details] Reproducing example. Description of problem: System headers define the identifier BIG_ENDIAN in a program that does not include any platform-specific headers, thus changing the meaning of a program that checks this particular symbol. Since BIG_ENDIAN is not a symbol reserved for the implementation, this is a standards violation. Version-Release number of selected component (if applicable): CentOS 7.2.1511 How reproducible: Always. Steps to Reproduce: 1. g++ -c big_endian_predefined.cpp Actual results: #error message Expected results: Successful compilation. Additional info: It looks like BIG_ENDIAN and other symbols like it become defined when __USE_BSD is defined.