If Data_First is set to the special value of -1 (the default), then we
cannot look at Data (Data_First).
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* libgnat/s-regpat.ads: Change Data_First to Data'First. Change
"still" to "always". Similar changes for Data_Last.diff --git a/gcc/ada/libgnat/s-regpat.ads b/gcc/ada/libgnat/s-regpat.ads
--- a/gcc/ada/libgnat/s-regpat.ads
+++ b/gcc/ada/libgnat/s-regpat.ads
@@ -482,18 +482,17 @@ package System.Regpat is
-- Data_First is the lower bound for the match, i.e. Data (Data_First)
-- will be the first character to be examined. If Data_First is set to
-- the special value of -1 (the default), then the first character to
- -- be examined is Data (Data_First). However, the regular expression
- -- character ^ (start of string) still refers to the first character
+ -- be examined is Data (Data'First). However, the regular expression
+ -- character ^ (start of string) always refers to the first character
-- of the full string (Data (Data'First)), which is why there is a
-- separate mechanism for specifying Data_First.
-- Data_Last is the upper bound for the match, i.e. Data (Data_Last)
-- will be the last character to be examined. If Data_Last is set to
-- the special value of Positive'Last (the default), then the last
- -- character to be examined is Data (Data_Last). However, the regular
- -- expression character $ (end of string) still refers to the last
- -- character of the full string (Data (Data'Last)), which is why there
- -- is a separate mechanism for specifying Data_Last.
+ -- character to be examined is Data (Data'Last). However, the regular
+ -- expression character $ (end of string) always refers to the last
+ -- character of the full string (Data (Data'Last)).
-- Note: the use of Data_First and Data_Last is not equivalent to
-- simply passing a slice as Expression because of the handling of
