From: Marek Polacek <polacek@redhat.com>
Date: Thu, 11 Jul 2024 19:57:43 +0000 (-0400)
Subject: eh: ICE with std::initializer_list and ASan [PR115865]
X-Git-Tag: basepoints/gcc-16~7412
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1e60a6abfece40c7bf55d6ca0a439078d3f5159a;p=thirdparty%2Fgcc.git

eh: ICE with std::initializer_list and ASan [PR115865]

Here we ICE with -fsanitize=address on

  std::initializer_list x = { 1, 2, 3 };

since r14-8681, which removed .ASAN_MARK calls on TREE_STATIC variables.
That means that lower_try_finally now instead of

  try
    {
      .ASAN_MARK (UNPOISON, &C.0, 12);
      x = {};
      x._M_len = 3;
      x._M_array = &C.0;
    }
  finally
    {
      .ASAN_MARK (POISON, &C.0, 12);
    }

gets:

  try
    {
      x = {};
      x._M_len = 3;
      x._M_array = &C.0;
    }
  finally
    {

    }

and we ICE on the empty finally in lower_try_finally_onedest while
getting get_eh_else.

	PR c++/115865

gcc/ChangeLog:

	* tree-eh.cc (get_eh_else): Check that the result of
	gimple_seq_first_stmt is non-null.

gcc/testsuite/ChangeLog:

	* g++.dg/asan/initlist2.C: New test.

Co-authored-by: Jakub Jelinek  <jakub@redhat.com>
---

diff --git a/gcc/testsuite/g++.dg/asan/initlist2.C b/gcc/testsuite/g++.dg/asan/initlist2.C
new file mode 100644
index 000000000000..bce5410be339
--- /dev/null
+++ b/gcc/testsuite/g++.dg/asan/initlist2.C
@@ -0,0 +1,16 @@
+// PR c++/115865
+// { dg-do compile }
+// { dg-options "-fsanitize=address" }
+
+typedef decltype(sizeof(char)) size_t;
+
+namespace std {
+template <class> class initializer_list {
+  int *_M_array;
+  size_t _M_len;
+};
+}
+
+int main() {
+  std::initializer_list x = { 1, 2, 3 };
+}
diff --git a/gcc/tree-eh.cc b/gcc/tree-eh.cc
index a776ad5c92ba..9609bdc0d9b7 100644
--- a/gcc/tree-eh.cc
+++ b/gcc/tree-eh.cc
@@ -950,7 +950,7 @@ static inline geh_else *
 get_eh_else (gimple_seq finally)
 {
   gimple *x = gimple_seq_first_stmt (finally);
-  if (gimple_code (x) == GIMPLE_EH_ELSE)
+  if (x && gimple_code (x) == GIMPLE_EH_ELSE)
     {
       gcc_assert (gimple_seq_singleton_p (finally));
       return as_a <geh_else *> (x);