https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85652
Bug ID: 85652
Summary: -Wformat-overflow warning silenced by -fpic/-fPIC
Product: gcc
Version: 8.1.0
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: ---
Target: x86_64-linux
Created attachment 44070
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44070&action=edit
testcase
The attached creduce'd testcase warns with -Wformat-overflow:
$ g++-8 -c -O2 -Wformat-overflow t7.cpp
t7.cpp: In function 'void f()':
t7.cpp:15:16: warning: '%s' directive writing up to 55 bytes into a region of
size 12 [-Wformat-overflow=]
t7.cpp:9:10:
return c[d];
~~~~
t7.cpp:15:16:
sprintf(e, "xxxxxxxxxxxx %s / %s", "", g);
^~~~~~~~~~~~~~~~~~~~~~
t7.cpp:15:12: note: 'sprintf' output between 17 and 72 bytes into a destination
of size 28
sprintf(e, "xxxxxxxxxxxx %s / %s", "", g);
~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
But when -fpic or -fPIC is added, the warning vanishes. Current trunk@259927
shows the same behaviour.
