The routine to output strings in an optimized manner has an overflow
error in case of very large strings.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* libgnat/s-ststop.ads: Fix typo.
* libgnat/s-ststop.adb (Read, Write): Fix block number
computation to avoid overflows in case of large strings.diff --git a/gcc/ada/libgnat/s-ststop.adb b/gcc/ada/libgnat/s-ststop.adb
--- a/gcc/ada/libgnat/s-ststop.adb
+++ b/gcc/ada/libgnat/s-ststop.adb
@@ -216,21 +216,25 @@ package body System.Strings.Stream_Ops is
declare
-- Determine the size in BITS of the block necessary to contain
-- the whole string.
+ -- Since we are dealing with strings indexed by natural, there
+ -- is no risk of overflow when using a Long_Long_Integer.
- Block_Size : constant Natural :=
- Integer (Item'Last - Item'First + 1) * ET_Size;
+ Block_Size : constant Long_Long_Integer :=
+ Item'Length * Long_Long_Integer (ET_Size);
-- Item can be larger than what the default block can store,
- -- determine the number of whole reads necessary to read the
+ -- determine the number of whole writes necessary to output the
-- string.
- Blocks : constant Natural := Block_Size / Default_Block_Size;
+ Blocks : constant Natural :=
+ Natural (Block_Size / Long_Long_Integer (Default_Block_Size));
-- The size of Item may not be a multiple of the default block
- -- size, determine the size of the remaining chunk in BITS.
+ -- size, determine the size of the remaining chunk.
Rem_Size : constant Natural :=
- Block_Size mod Default_Block_Size;
+ Natural
+ (Block_Size mod Long_Long_Integer (Default_Block_Size));
-- String indexes
@@ -337,20 +341,25 @@ package body System.Strings.Stream_Ops is
declare
-- Determine the size in BITS of the block necessary to contain
-- the whole string.
+ -- Since we are dealing with strings indexed by natural, there
+ -- is no risk of overflow when using a Long_Long_Integer.
- Block_Size : constant Natural := Item'Length * ET_Size;
+ Block_Size : constant Long_Long_Integer :=
+ Item'Length * Long_Long_Integer (ET_Size);
-- Item can be larger than what the default block can store,
-- determine the number of whole writes necessary to output the
-- string.
- Blocks : constant Natural := Block_Size / Default_Block_Size;
+ Blocks : constant Natural :=
+ Natural (Block_Size / Long_Long_Integer (Default_Block_Size));
-- The size of Item may not be a multiple of the default block
-- size, determine the size of the remaining chunk.
Rem_Size : constant Natural :=
- Block_Size mod Default_Block_Size;
+ Natural
+ (Block_Size mod Long_Long_Integer (Default_Block_Size));
-- String indexes
diff --git a/gcc/ada/libgnat/s-ststop.ads b/gcc/ada/libgnat/s-ststop.ads
--- a/gcc/ada/libgnat/s-ststop.ads
+++ b/gcc/ada/libgnat/s-ststop.ads
@@ -53,7 +53,7 @@
-- or
-- String_Output_Blk_IO (Some_Stream, Some_String);
--- String_Output form is used if pragma Restrictions (No_String_Optimziations)
+-- String_Output form is used if pragma Restrictions (No_String_Optimizations)
-- is active, which requires element by element operations. The BLK_IO form
-- is used if this restriction is not set, allowing block optimization.
