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* [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined @ 2023-05-04 6:47 dani at danielbertalan dot dev 2023-05-04 7:21 ` [Bug middle-end/109727] " rguenth at gcc dot gnu.org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: dani at danielbertalan dot dev @ 2023-05-04 6:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109727 Bug ID: 109727 Summary: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined Product: gcc Version: 13.1.0 Status: UNCONFIRMED Keywords: diagnostic Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: dani at danielbertalan dot dev Target Milestone: --- The following code results in a -Warray-bounds warning with GCC 13.1+ and -fsanitize=undefined. No diagnostics are produced by older compilers or if UBSan is not enabled. template <unsigned inline_capacity> struct ByteBuffer { static ByteBuffer create_uninitialized(); static void copy() { auto new_buf = create_uninitialized(); new_buf.data(); } char *data() { return m_inline ? m_inline_buffer : m_outline_buffer; } union { char m_inline_buffer[inline_capacity]; char *m_outline_buffer; }; bool m_inline; }; void test() { ByteBuffer<56> buf1; buf1.data(); ByteBuffer<2>::copy(); } Compile with g++ -O2 -Warray-bounds -fsanitize=undefined: In member function 'char* ByteBuffer<inline_capacity>::data() [with unsigned int inline_capacity = 56]', inlined from 'char* ByteBuffer<inline_capacity>::data() [with unsigned int inline_capacity = 2]' at <source>:7:9, inlined from 'static void ByteBuffer<inline_capacity>::copy() [with unsigned int inline_capacity = 2]' at <source>:5:19, inlined from 'void test()' at <source>:18:22: <source>:7:34: warning: array subscript 'ByteBuffer<56>[0]' is partly outside array bounds of 'ByteBuffer<2> [1]' [-Warray-bounds=] 7 | char *data() { return m_inline ? m_inline_buffer : m_outline_buffer; } | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ <source>: In function 'void test()': <source>:4:12: note: object 'new_buf' of size 16 4 | auto new_buf = create_uninitialized(); | ^~~~~~~ It looks like something about the two SSO buffer lengths gets confused: the error trace incorrectly indicates that ByteBuffer<56>::data() is getting inlined into ByteBuffer<2>::data(). Removing either this template parameter, the m_outline_buffer union member, or calling ByteBuffer::copy with the same template parameter in test() fixes the diagnostic. https://godbolt.org/z/6rqEnhP6q ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/109727] [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined 2023-05-04 6:47 [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined dani at danielbertalan dot dev @ 2023-05-04 7:21 ` rguenth at gcc dot gnu.org 2023-07-27 9:26 ` rguenth at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2023-05-04 7:21 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109727 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Blocks| |56456 Target Milestone|--- |13.2 Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56456 [Bug 56456] [meta-bug] bogus/missing -Warray-bounds ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/109727] [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined 2023-05-04 6:47 [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined dani at danielbertalan dot dev 2023-05-04 7:21 ` [Bug middle-end/109727] " rguenth at gcc dot gnu.org @ 2023-07-27 9:26 ` rguenth at gcc dot gnu.org 2024-03-08 15:37 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug middle-end/109727] [13/14/15 " jakub at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2023-07-27 9:26 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109727 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|13.2 |13.3 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- GCC 13.2 is being released, retargeting bugs to GCC 13.3. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/109727] [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined 2023-05-04 6:47 [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined dani at danielbertalan dot dev 2023-05-04 7:21 ` [Bug middle-end/109727] " rguenth at gcc dot gnu.org 2023-07-27 9:26 ` rguenth at gcc dot gnu.org @ 2024-03-08 15:37 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug middle-end/109727] [13/14/15 " jakub at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: law at gcc dot gnu.org @ 2024-03-08 15:37 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109727 Jeffrey A. Law <law at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |law at gcc dot gnu.org Priority|P3 |P2 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug middle-end/109727] [13/14/15 Regression] -Warray-bounds false positive with -fsanitize=undefined 2023-05-04 6:47 [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined dani at danielbertalan dot dev ` (2 preceding siblings ...) 2024-03-08 15:37 ` law at gcc dot gnu.org @ 2024-05-21 9:14 ` jakub at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: jakub at gcc dot gnu.org @ 2024-05-21 9:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109727 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|13.3 |13.4 --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- GCC 13.3 is being released, retargeting bugs to GCC 13.4. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-05-21 9:14 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-05-04 6:47 [Bug c++/109727] New: [13/14 Regression] -Warray-bounds false positive with -fsanitize=undefined dani at danielbertalan dot dev 2023-05-04 7:21 ` [Bug middle-end/109727] " rguenth at gcc dot gnu.org 2023-07-27 9:26 ` rguenth at gcc dot gnu.org 2024-03-08 15:37 ` law at gcc dot gnu.org 2024-05-21 9:14 ` [Bug middle-end/109727] [13/14/15 " jakub at gcc dot gnu.org
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