Replace use of SPARK_Mode Off on callers of procedure Move by stronger
preconditions, as mandated by Ada RM A.4.3, so that calls to the
corresponding functions inside the procedure bodies are provably
correct.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* libgnat/a-strfix.adb (Delete, Insert, Overwrite,
Replace_Slice): Remove SPARK_Mode Off.
* libgnat/a-strfix.ads (Insert, Overwrite, Replace_Slice):
Strengthen precondition.diff --git a/gcc/ada/libgnat/a-strfix.adb b/gcc/ada/libgnat/a-strfix.adb
--- a/gcc/ada/libgnat/a-strfix.adb
+++ b/gcc/ada/libgnat/a-strfix.adb
@@ -214,7 +214,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
-- Lemma_Split --
-----------------
- procedure Lemma_Split (Result : String) is
+ procedure Lemma_Split (Result : String)
+ is
begin
for K in Ptr + 1 .. Ptr + Right'Length loop
Lemma_Mod (K - 1);
@@ -307,7 +308,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
From : Positive;
Through : Natural;
Justify : Alignment := Left;
- Pad : Character := Space) with SPARK_Mode => Off is
+ Pad : Character := Space)
+ is
begin
Move (Source => Delete (Source, From, Through),
Target => Source,
@@ -403,7 +405,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
(Source : in out String;
Before : Positive;
New_Item : String;
- Drop : Truncation := Error) with SPARK_Mode => Off is
+ Drop : Truncation := Error)
+ is
begin
Move (Source => Insert (Source, Before, New_Item),
Target => Source,
@@ -419,7 +422,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
Target : out String;
Drop : Truncation := Error;
Justify : Alignment := Left;
- Pad : Character := Space) with SPARK_Mode => Off
+ Pad : Character := Space)
+ with SPARK_Mode => Off
is
Sfirst : constant Integer := Source'First;
Slast : constant Integer := Source'Last;
@@ -571,7 +575,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
(Source : in out String;
Position : Positive;
New_Item : String;
- Drop : Truncation := Right) with SPARK_Mode => Off is
+ Drop : Truncation := Right)
+ is
begin
Move (Source => Overwrite (Source, Position, New_Item),
Target => Source,
@@ -648,7 +653,8 @@ package body Ada.Strings.Fixed with SPARK_Mode is
By : String;
Drop : Truncation := Error;
Justify : Alignment := Left;
- Pad : Character := Space) with SPARK_Mode => Off is
+ Pad : Character := Space)
+ is
begin
Move (Replace_Slice (Source, Low, High, By), Source, Drop, Justify, Pad);
end Replace_Slice;
diff --git a/gcc/ada/libgnat/a-strfix.ads b/gcc/ada/libgnat/a-strfix.ads
--- a/gcc/ada/libgnat/a-strfix.ads
+++ b/gcc/ada/libgnat/a-strfix.ads
@@ -904,7 +904,15 @@ package Ada.Strings.Fixed with SPARK_Mode is
Justify : Alignment := Left;
Pad : Character := Space)
with
- Pre => Low - 1 <= Source'Last,
+ Pre =>
+ Low - 1 <= Source'Last
+ and then High >= Source'First - 1
+ and then (if High >= Low
+ then Natural'Max (0, Low - Source'First)
+ <= Natural'Last
+ - By'Length
+ - Natural'Max (Source'Last - High, 0)
+ else Source'Length <= Natural'Last - By'Length),
-- Incomplete contract
@@ -966,7 +974,9 @@ package Ada.Strings.Fixed with SPARK_Mode is
New_Item : String;
Drop : Truncation := Error)
with
- Pre => Before - 1 in Source'First - 1 .. Source'Last,
+ Pre =>
+ Before - 1 in Source'First - 1 .. Source'Last
+ and then Source'Length <= Natural'Last - New_Item'Length,
-- Incomplete contract
@@ -1033,7 +1043,11 @@ package Ada.Strings.Fixed with SPARK_Mode is
New_Item : String;
Drop : Truncation := Right)
with
- Pre => Position - 1 in Source'First - 1 .. Source'Last,
+ Pre =>
+ Position - 1 in Source'First - 1 .. Source'Last
+ and then
+ (if Position - Source'First >= Source'Length - New_Item'Length
+ then Position - Source'First <= Natural'Last - New_Item'Length),
-- Incomplete contract
