Bug 230701
| Summary: | Warnings issued by g++4 about broken strict-aliasing rules in /usr/include/c++/3.4.3/bits/basic_string.h when compiling with -fstrict-aliasing -Wall | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 4 | Reporter: | Ratko Veprek <veprek> |
| Component: | gcc4 | Assignee: | Jakub Jelinek <jakub> |
| Status: | CLOSED WONTFIX | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | medium | ||
| Version: | 4.4 | ||
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2007-03-02 12:05:16 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
The -Wstrict-aliasing warning support was added only in 4.1+ and libstdc++-v3 4.1+ headers have been tweaked to shut the warning in this case down by additional cast through void *, but as in RHEL4 libstdc++-v3 3.4.6 is used, you get that harmless warning. The code is believed to be ok, because _S_empty_rep_storage is never written into at runtime (only initialized to 0 by the linker). |
Hi there! Description of problem: There may be some problem with the backwards compatiblity between g++-4.1 (Red Hat 4.1.0-18) and libg++ 3.4.3. When using -fstrict-aliasing optimization flag, i get warnings about broken strict-aliasing rules. The warnings do not apper when using g++ 3.4.6. Version-Release number of selected component (if applicable): Red Hat Enterprise Linux AS release 4 (Nahant Update 4) g++4 (GCC) 4.1.0 20060515 (Red Hat 4.1.0-18) How reproducible: always, just compile the following code on an x86_64 machine #include <string> int main() { std::string sausage("huhu"); } using g++4 -Wall -fstrict-aliasing -c test.cc then leave -fstrict-aliasing or use g++ should I take that warning message serious? Thank you very much! Best regards ratko