https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92634
Bug ID: 92634
Summary: [gcc-8 regression] -fsanitize=undefined erroneous null
pointer check
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: amodra at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
Created attachment 47337
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47337&action=edit
testcase
-fsanitize=undefined inserts bogus pointer checks on expressions that
effectively cast a pointer to a union to a pointer to one of the elements of
that union.
&p->field does not dereference p, just as &*p and &p[i] do not.
This bites in binutils sources (eg. see ldlang.c lang_for_each_input_file),
where &p->field is used in preference to (type_of_field *) p, since the cast
loses some type checking.
