[IPA] Clang does not warn about uninitialized variable


Bugzilla Link	PR5842
Status	NEW
Importance	P normal
Reported by	Oliver McFadden (omcfadde@gmail.com)
Reported on	2009-12-20 20:30:56 -0800
Last modified on	2011-06-01 15:28:44 -0700
Version	trunk
Hardware	PC Linux
CC	ali.2006.amin@gmail.com, llvm-bugs@lists.llvm.org
Fixed by commit(s)
Attachments	`unused.c` (599 bytes, text/plain)
Blocks
Blocked by
See also

Created attachment 3966
Testcase

I've attached a testcase showing this problem. Clang correctly detects that the
return value from PlaneGetDist() is unused, but the normal vector (N) from
PlaneGetNormal is also unused, and Clang doesn't warn about this.

I suspect this might require IPA functionality, so feel free to mark it as a
duplicate of another bug - I don't feel I have enough experience with Clang to
know for sure whether this is a duplicate.

Compile as: scan-build gcc unused.c -Wunused-parameter -Wall

ANALYZE: unused.c PlaneGetNormal
ANALYZE: unused.c PlaneGetDist
ANALYZE: unused.c main
unused.c:34:3: warning: Value stored to 'd' is never read
  d = PlaneGetDist (P);
  ^   ~~~~~~~~~~~~~~~~
1 diagnostic generated.
scan-build: 1 bugs found.
scan-build: Run 'scan-view /tmp/scan-build-2009-12-21-16' to examine bug
reports.

Quuxplusone / LLVMBugzillaTest

[IPA] Clang does not warn about uninitialized variable #6325