[gcc r14-10461] eh: ICE with std::initializer_list and ASan [PR115865]

[Marek Polacek via Gcc-cvs]

https://gcc.gnu.org/g:493035c8780cd510a680a791d0c7f94368164352

commit r14-10461-g493035c8780cd510a680a791d0c7f94368164352
Author: Marek Polacek <pola...@redhat.com>
Date:   Thu Jul 11 15:57:43 2024 -0400

    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  <ja...@redhat.com>
    (cherry picked from commit 1e60a6abfece40c7bf55d6ca0a439078d3f5159a)

Diff:
---
 gcc/testsuite/g++.dg/asan/initlist2.C | 16 ++++++++++++++++
 gcc/tree-eh.cc                        |  2 +-
 2 files changed, 17 insertions(+), 1 deletion(-)

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);