https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64057
Bug ID: 64057
Summary: Overlapping memcpy generated for array assignment
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ada
Assignee: unassigned at gcc dot gnu.org
Reporter: tobiasu at tmux dot org
Created attachment 34099
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34099&action=edit
memcpy wrapper with overlap detection
The Ada front end generates a overlapping memcpy call for some array
assignments.
Using a strict version of memcpy that checks for overlap breaks gnat 4.8 and
4.9 on my Linux and OpenBSD test systems. Other applications compiled with gnat
may be affected as well.
Easy way to reproduce:
Build gnat and ^C once gcc/ada/bldtools/sinfo is generated.
Build the attached memcpy wrapper or patch your libc with checks.
$ cd $BUILD/gcc/ada/bldtools/sinfo
$ LD_PRELOAD=./memcpy.so gdb ./xsinfo
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Reading symbols from ./xsinfo...(no debugging symbols found)...done.
(gdb) run
Starting program:
/home/tulmer/tmp/gcc/src/gcc-build/gcc/ada/bldtools/sinfo/xsinfo
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
Check for field name consistency
OK
Check for function consistency
OK
Check for missing functions
OK
Check for set procedure consistency
OK
Check for missing set procedures
OK
Check pragma Inlines are all for existing subprograms
memcpy(0x6c125c, 0x6c1260, 14)
dest=Set_ABE_Is_Certainbs src=ABE_Is_Certainbs
Program received signal SIGABRT, Aborted.
0x00007ffff786aa97 in raise () from /usr/lib/libc.so.6
(gdb) bt
#0 0x00007ffff786aa97 in raise () from /usr/lib/libc.so.6
#1 0x00007ffff786be6a in abort () from /usr/lib/libc.so.6
#2 0x00007ffff7bda879 in memcpy () from ./memcpy.so
#3 0x000000000042c20e in ada.strings.unbounded.set_unbounded_string ()
#4 0x0000000000443b31 in gnat.spitbol.patterns.xmatch ()
#5 0x000000000044488b in gnat.spitbol.patterns.match ()
#6 0x000000000040afd0 in csinfo ()
#7 0x000000000041bb69 in xsinfo ()
Let me know if you need more info
