[PATCH] gimple-low: Remove .ASAN_MARK calls on TREE_STATIC variables [PR113531]

[Jakub Jelinek]

On Wed, Jan 31, 2024 at 01:04:22PM +0100, Richard Biener wrote:
> > Like this, so far just tested on the testcase.  Ok for trunk if it passes
> > bootstrap/regtest on top of Jason's patch?
> 
> Note we fold all - well, all builtin - calls during gimple lowering.

Internal calls aren't builtin, so those aren't folded.

> Maybe we can put this special-casing there instead? (gimple-low.cc:797,
> you possibly have to replace with a GIMPLE_NOP)

But sure, we can do it there as well.
In that case I think we don't need it in asan.cc though, because
gimple-low.cc is guaranteed to be performed on all statements from
gimplification that survive in the IL.

So like this?

2024-01-31  Jakub Jelinek  <ja...@redhat.com>
            Jason Merrill  <ja...@redhat.com>

        PR c++/113531
        * gimple-low.cc (lower_stmt): Remove .ASAN_MARK calls
        on variables which were promoted to TREE_STATIC.

        * g++.dg/asan/initlist1.C: New test.

--- gcc/gimple-low.cc.jj        2024-01-03 11:51:22.133861623 +0100
+++ gcc/gimple-low.cc   2024-01-31 16:16:21.326927572 +0100
@@ -790,6 +790,21 @@ lower_stmt (gimple_stmt_iterator *gsi, s
            return;
          }
 
+       if (gimple_call_internal_p (stmt, IFN_ASAN_MARK))
+         {
+           tree base = gimple_call_arg (stmt, 1);
+           gcc_checking_assert (TREE_CODE (base) == ADDR_EXPR);
+           tree decl = TREE_OPERAND (base, 0);
+           if (VAR_P (decl) && TREE_STATIC (decl))
+             {
+               /* Don't poison a variable with static storage; it might have
+                  gotten marked before gimplify_init_constructor promoted it
+                  to static.  */
+               gsi_remove (gsi, true);
+               return;
+             }
+         }
+
        /* We delay folding of built calls from gimplification to
           here so the IL is in consistent state for the diagnostic
           machineries job.  */
--- gcc/testsuite/g++.dg/asan/initlist1.C.jj    2024-01-31 16:09:58.071289511 
+0100
+++ gcc/testsuite/g++.dg/asan/initlist1.C       2024-01-31 16:09:58.071289511 
+0100
@@ -0,0 +1,20 @@
+// PR c++/113531
+// { dg-do run { target c++11 } }
+// { dg-additional-options "-fsanitize=address" }
+
+#include <initializer_list>
+
+void f(int) { }
+
+void g()
+{
+  for (auto i : { 1, 2, 3 })
+    f (i);
+  f(42);
+}
+
+int main()
+{
+  g();
+  g();
+}


        Jakub