The following fixes removal of sanitizer IFN calls during LTO streaming
in when not linking with -fsanitize= to not interfer with IPA reference
nodes that might be attached to those stmts. The easiest idea I could
come up with that would also work with IPA passes refering to those
refs is to replace the IFN call with a NOP-like one. The following
patch does this, the next DCE pass will then remove those stmts
(or at -O0 expand will expand them to nothing). If we start to
use this replacement trick for calls with a LHS DCE would need to
be taught to replace the LHS with a default-def (or if aggregate
just ignore it). OTOH such replacement would be fishy.
Bootstrap and regtest in progress.
Any comments?
Thanks,
Richard.
2017-12-15 Richard Biener <rguent...@suse.de>
PR lto/83388
* internal-fn.def (IFN_NOP): Add.
* internal-fn.c (expand_NOP): Do nothing.
* lto-streamer-in.c (input_function): Instead of removing
sanitizer calls replace them with IFN_NOP calls.
* gcc.dg/lto/pr83388_0.c: New testcase.
Index: gcc/internal-fn.def
===================================================================
--- gcc/internal-fn.def (revision 255678)
+++ gcc/internal-fn.def (working copy)
@@ -254,6 +254,9 @@ DEF_INTERNAL_FN (LAUNDER, ECF_LEAF | ECF
/* Divmod function. */
DEF_INTERNAL_FN (DIVMOD, ECF_CONST | ECF_LEAF, NULL)
+/* A NOP function with aribtrary arguments and return value. */
+DEF_INTERNAL_FN (NOP, ECF_CONST | ECF_LEAF | ECF_NOTHROW, NULL)
+
#undef DEF_INTERNAL_INT_FN
#undef DEF_INTERNAL_FLT_FN
#undef DEF_INTERNAL_FLT_FLOATN_FN
Index: gcc/internal-fn.c
===================================================================
--- gcc/internal-fn.c (revision 255678)
+++ gcc/internal-fn.c (working copy)
@@ -2722,6 +2722,14 @@ expand_DIVMOD (internal_fn, gcall *call_
target, VOIDmode, EXPAND_NORMAL);
}
+/* Expand a NOP. */
+
+static void
+expand_NOP (internal_fn, gcall *call_stmt)
+{
+ /* Nothing. But it shouldn't really prevail. */
+}
+
/* Expand a call to FN using the operands in STMT. FN has a single
output operand and NARGS input operands. */
Index: gcc/lto-streamer-in.c
===================================================================
--- gcc/lto-streamer-in.c (revision 255678)
+++ gcc/lto-streamer-in.c (working copy)
@@ -1136,41 +1136,47 @@ input_function (tree fn_decl, struct dat
if (is_gimple_call (stmt)
&& gimple_call_internal_p (stmt))
{
+ bool replace = false;
switch (gimple_call_internal_fn (stmt))
{
case IFN_UBSAN_NULL:
if ((flag_sanitize
& (SANITIZE_NULL | SANITIZE_ALIGNMENT)) == 0)
- remove = true;
+ replace = true;
break;
case IFN_UBSAN_BOUNDS:
if ((flag_sanitize & SANITIZE_BOUNDS) == 0)
- remove = true;
+ replace = true;
break;
case IFN_UBSAN_VPTR:
if ((flag_sanitize & SANITIZE_VPTR) == 0)
- remove = true;
+ replace = true;
break;
case IFN_UBSAN_OBJECT_SIZE:
if ((flag_sanitize & SANITIZE_OBJECT_SIZE) == 0)
- remove = true;
+ replace = true;
break;
case IFN_UBSAN_PTR:
if ((flag_sanitize & SANITIZE_POINTER_OVERFLOW) == 0)
- remove = true;
+ replace = true;
break;
case IFN_ASAN_MARK:
if ((flag_sanitize & SANITIZE_ADDRESS) == 0)
- remove = true;
+ replace = true;
break;
case IFN_TSAN_FUNC_EXIT:
if ((flag_sanitize & SANITIZE_THREAD) == 0)
- remove = true;
+ replace = true;
break;
default:
break;
}
- gcc_assert (!remove || gimple_call_lhs (stmt) == NULL_TREE);
+ if (replace)
+ {
+ gimple_call_set_internal_fn (as_a <gcall *> (stmt),
+ IFN_NOP);
+ update_stmt (stmt);
+ }
}
}
if (remove)
Index: gcc/testsuite/gcc.dg/lto/pr83388_0.c
===================================================================
--- gcc/testsuite/gcc.dg/lto/pr83388_0.c (nonexistent)
+++ gcc/testsuite/gcc.dg/lto/pr83388_0.c (working copy)
@@ -0,0 +1,18 @@
+/* { dg-lto-do link } */
+/* { dg-lto-options { { -O2 -flto -fsanitize=null } { -O0 -flto
-fsanitize=null } } } */
+/* { dg-extra-ld-options { -fno-sanitize=null -r -nostdlib } } */
+
+enum { a } e(void);
+struct C {
+ int d;
+} c;
+long f;
+void g(long);
+static void i(_Bool h) {
+ struct C *a = ({ ({ &c; }); });
+ if (e()) {
+ int b = a->d;
+ g(f);
+ }
+}
+void j(void) { i(a); }
