From: Ronan Desplanques <desplanq...@adacore.com>
Before this patch, format strings ending with "%%" (two consecutive
percent signs) caused GNAT.Formatted_String."-" to give the wrong
output, and cause the various GNAT.Formatted_String."&" to raise
exceptions with misleading error messages.
Also before this patch, a bug in GNAT.Formatted_String."-" caused
characters from the format string to be dropped. Calling
GNAT.Formatted_String."-" on an instance of
GNAT.Formatted_String.Formatted_String caused subsequent uses of
that instance to return wrong results.
In addition to fixing the parsing of format strings, this patch
centralizes the detection of format specifiers in a unique
procedure.
gcc/ada/
* libgnat/g-forstr.adb
(Advance_And_Accumulate_Until_Next_Specifier): New procedure.
("-"): Replace inline code with call to
Advance_And_Accumulate_Until_Next_Specifier.
(Next_Format): likewise.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/libgnat/g-forstr.adb | 67 +++++++++++++++++++-----------------
1 file changed, 36 insertions(+), 31 deletions(-)
diff --git a/gcc/ada/libgnat/g-forstr.adb b/gcc/ada/libgnat/g-forstr.adb
index 8821de6f280..8353e2c4ad8 100644
--- a/gcc/ada/libgnat/g-forstr.adb
+++ b/gcc/ada/libgnat/g-forstr.adb
@@ -77,6 +77,12 @@ package body GNAT.Formatted_String is
Value_Needed : Natural range 0 .. 2 := 0;
end record;
+ procedure Advance_And_Accumulate_Until_Next_Specifier
+ (Format : Formatted_String);
+ -- Advance Format.D.Index until either the next format specifier is
+ -- encountered, or the end of Format.D.Format is reached. The characters
+ -- advanced over are appended to Format.D.Result.
+
procedure Next_Format
(Format : Formatted_String;
F_Spec : out F_Data;
@@ -139,29 +145,13 @@ package body GNAT.Formatted_String is
---------
function "-" (Format : Formatted_String) return String is
- F : String renames Format.D.Format;
- J : Natural renames Format.D.Index;
- R : Unbounded_String := Format.D.Result;
-
begin
-- Make sure we get the remaining character up to the next unhandled
-- format specifier.
- while (J <= F'Length and then F (J) /= '%')
- or else (J < F'Length - 1 and then F (J + 1) = '%')
- loop
- Append (R, F (J));
-
- -- If we have two consecutive %, skip the second one
-
- if F (J) = '%' and then J < F'Length - 1 and then F (J + 1) = '%' then
- J := J + 1;
- end if;
-
- J := J + 1;
- end loop;
+ Advance_And_Accumulate_Until_Next_Specifier (Format);
- return To_String (R);
+ return To_String (Format.D.Result);
end "-";
---------
@@ -318,6 +308,33 @@ package body GNAT.Formatted_String is
F.D.Ref_Count := F.D.Ref_Count + 1;
end Adjust;
+ -------------------------------------------------
+ -- Advance_And_Accumulate_Until_Next_Specifier --
+ -------------------------------------------------
+
+ procedure Advance_And_Accumulate_Until_Next_Specifier
+ (Format : Formatted_String)
+ is
+ begin
+ loop
+ if Format.D.Index > Format.D.Format'Last then
+ exit;
+ end if;
+
+ if Format.D.Format (Format.D.Index) /= '%' then
+ Append (Format.D.Result, Format.D.Format (Format.D.Index));
+ Format.D.Index := Format.D.Index + 1;
+ elsif Format.D.Index + 1 <= Format.D.Format'Last
+ and then Format.D.Format (Format.D.Index + 1) = '%'
+ then
+ Append (Format.D.Result, '%');
+ Format.D.Index := Format.D.Index + 2;
+ else
+ exit;
+ end if;
+ end loop;
+ end Advance_And_Accumulate_Until_Next_Specifier;
+
--------------------
-- Decimal_Format --
--------------------
@@ -505,19 +522,7 @@ package body GNAT.Formatted_String is
-- Got to next %
- while (J <= F'Last and then F (J) /= '%')
- or else (J < F'Last - 1 and then F (J + 1) = '%')
- loop
- Append (Format.D.Result, F (J));
-
- -- If we have two consecutive %, skip the second one
-
- if F (J) = '%' and then J < F'Last - 1 and then F (J + 1) = '%' then
- J := J + 1;
- end if;
-
- J := J + 1;
- end loop;
+ Advance_And_Accumulate_Until_Next_Specifier (Format);
if J >= F'Last or else F (J) /= '%' then
raise Format_Error with "no format specifier found for parameter"
--
2.34.1
