[gcc r16-48] Add assert to array_slice::begin/end

[Andrew Pinski via Gcc-cvs]

https://gcc.gnu.org/g:d508d24282c6a8172be2abcb2223232f452b667f

commit r16-48-gd508d24282c6a8172be2abcb2223232f452b667f
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date:   Thu Jan 9 12:53:27 2025 -0800

    Add assert to array_slice::begin/end
    
    So while debugging PR 118320, I found it was useful to have
    an assert inside array_slice::begin/end that the array slice isvalid
    rather than getting an segfault. This adds an assert that is only
    enabled for checking.
    
    OK? Bootstrapped and tested on x86_64-linux-gnu.
    
    gcc/ChangeLog:
    
            * vec.h (array_slice::begin): Assert that the
            slice is valid.
            (array_slice::end): Likewise.
    
    Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>

Diff:
---
 gcc/vec.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/gcc/vec.h b/gcc/vec.h
index 915df06f03e9..eae4b0feb4bc 100644
--- a/gcc/vec.h
+++ b/gcc/vec.h
@@ -2395,11 +2395,11 @@ public:
   array_slice (vec<OtherT, A, vl_embed> *v)
     : m_base (v ? v->address () : nullptr), m_size (v ? v->length () : 0) {}
 
-  iterator begin () { return m_base; }
-  iterator end () { return m_base + m_size; }
+  iterator begin () {  gcc_checking_assert (is_valid ()); return m_base; }
+  iterator end () {  gcc_checking_assert (is_valid ()); return m_base + 
m_size; }
 
-  const_iterator begin () const { return m_base; }
-  const_iterator end () const { return m_base + m_size; }
+  const_iterator begin () const { gcc_checking_assert (is_valid ()); return 
m_base; }
+  const_iterator end () const { gcc_checking_assert (is_valid ()); return 
m_base + m_size; }
 
   value_type &front ();
   value_type &back ();