| Message ID | 20130730143414.GL17022@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Jul 30, 2013 at 04:34:14PM +0200, Marek Polacek wrote: > This adds the bootstrap-ubsan.mk file so that > --with-build-config=bootstrap-ubsan be possible. I doesn't work yet, > though :(. One of the reasons is that we use -Werror and e.g. on the following testcase static int x; void foo (void) { int o = 1; x = x >> o; } with -O -fsanitize=undefined we generate: c.c:6:9: warning: ‘x.2’ is used uninitialized in this function [-Wuninitialized] x = x >> o; while with -O -fno-sanitize=undefined there isn't such warning. When sanitizing, in .uninit1 we have int x.3; int x.2; <bb 2>: x.3_3 = x.2_1(D) >> 1; x = x.3_3; and when no sanitizing int x.1; int x.0; <bb 2>: x.0_2 = x; x.1_3 = x.0_2 >> 1; x = x.1_3; The warning comes from warn_uninitialized_vars. The warning here seems incorrect, but I'm afraid there isn't much to do about this on the ubsan side of things. Marek
diff --git a/config/ChangeLog.ubsan b/config/ChangeLog.ubsan new file mode 100644 index 0000000..f7a2125 --- /dev/null +++ b/config/ChangeLog.ubsan @@ -0,0 +1,3 @@ +2013-07-30 Marek Polacek <polacek@redhat.com> + + * bootstrap-ubsan.mk: New. diff --git a/config/bootstrap-ubsan.mk b/config/bootstrap-ubsan.mk new file mode 100644 index 0000000..10543f6 --- /dev/null +++ b/config/bootstrap-ubsan.mk @@ -0,0 +1,7 @@ +# This option enables -fsanitize=undefined for stage2 and stage3. + +STAGE2_CFLAGS += -fsanitize=undefined +STAGE3_CFLAGS += -fsanitize=undefined +POSTSTAGE1_LDFLAGS += -fsanitize=undefined -static-libubsan \ + -B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/ubsan/ \