From: Tonu Naks <n...@adacore.com>
gcc/ada/ChangeLog:
* libgnat/i-cstrin.ads (Value): add documentation
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/libgnat/i-cstrin.ads | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/gcc/ada/libgnat/i-cstrin.ads b/gcc/ada/libgnat/i-cstrin.ads
index 0d057d074e5..5939fe041a4 100644
--- a/gcc/ada/libgnat/i-cstrin.ads
+++ b/gcc/ada/libgnat/i-cstrin.ads
@@ -100,6 +100,17 @@ is
-- The Value functions copy the contents of a chars_ptr object
-- into a char_array/String.
+ -- There is a guard for a storage error on an object declaration for
+ -- an array type with a modular index type with the size of
+ -- Long_Long_Integer. The special processing is needed in this case
+ -- to compute reliably the size of the object, and eventually, to
+ -- raise Storage_Error, when wrap-around arithmetic might compute
+ -- a meangingless size for the object.
+ --
+ -- The guard raises Storage_Error when
+ --
+ -- (Arr'Last / 2 - Arr'First / 2) > (2 ** 30)
+ --
function Value (Item : chars_ptr) return char_array with
Pre => Item /= Null_Ptr,
Global => (Input => C_Memory);
--
2.43.0
