[PATCH][PUSHED] c++: properly initialize UBSAN built-ins

[Martin Liška]

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Pushed based on Jakub's approval.

Thanks,
Martin

        PR c++/106062

gcc/ChangeLog:

        * ubsan.cc (sanitize_unreachable_fn): Change order of calls
        in order to initialize UBSAN built-ins.

gcc/testsuite/ChangeLog:

        * gfortran.dg/ubsan/pr106062.f90: New test.
---
 gcc/testsuite/gfortran.dg/ubsan/pr106062.f90 | 11 +++++++++++
 gcc/ubsan.cc                                 |  3 ++-
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gfortran.dg/ubsan/pr106062.f90

diff --git a/gcc/testsuite/gfortran.dg/ubsan/pr106062.f90 
b/gcc/testsuite/gfortran.dg/ubsan/pr106062.f90
new file mode 100644
index 00000000000..879a67eb749
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/ubsan/pr106062.f90
@@ -0,0 +1,11 @@
+! PR c++/106062
+! { dg-do compile }
+! { dg-options "-O2 -fsanitize=undefined" }
+
+call test (reshape ((/ 'a', 'b', 'c', 'd' /), (/ 2, 2 /)))
+contains
+  subroutine test (a)
+    character (*), dimension (:, :) :: a
+    if (len (a) .ne. 1) STOP 
+  end  
+end
diff --git a/gcc/ubsan.cc b/gcc/ubsan.cc
index f15026872a1..b6c4301dfaf 100644
--- a/gcc/ubsan.cc
+++ b/gcc/ubsan.cc
@@ -654,9 +654,10 @@ sanitize_unreachable_fn (tree *data, location_t loc)
     }
   else if (san)
     {
-      fn = builtin_decl_explicit (BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE);
+      /* Call ubsan_create_data first as it initializes SANITIZER built-ins.  
*/
       *data = ubsan_create_data ("__ubsan_unreachable_data", 1, &loc,
                                 NULL_TREE, NULL_TREE);
+      fn = builtin_decl_explicit (BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE);
       *data = build_fold_addr_expr_loc (loc, *data);
     }
   else
-- 
2.36.1