https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85420
Bug ID: 85420
Summary: More -Wrestrict false positives with
-fsanitize=undefined
Product: gcc
Version: 8.0.1
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: sirl at gcc dot gnu.org
Target Milestone: ---
Created attachment 43950
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43950&action=edit
C testcase
The attached testcases produce extra warnings of the "may overlap" kind with
-Wrestrict -fsanitize=undefined (PR85365 covers the "same destination" kind).
# gcc-8 -c -O2 -fsanitize=undefined -Wrestrict t5.c
t5.c: In function 'c':
t5.c:6:5: warning: 'strcpy' accessing 1 byte at offsets 0 and [0, 1] may
overlap 1 byte at offset 0 [-Wrestrict]
strcpy(b, b + a);
^~~~~~~~~~~~~~~~
g++-8 -c -O2 -fsanitize=undefined -Wrestrict t6.cpp
t6.cpp: In member function 'int c::m_fn1()':
t6.cpp:13:9: warning: 'char* strcat(char*, const char*)' accessing 4096 or more
bytes at offsets 0 and 4095 may overlap 1 byte at offset 4095 [-Wrestrict]
strcat(e, d.b);
~~~~~~^~~~~~~~
