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[multiple changes]

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2009-04-15  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch4.adb: improve error message on exponentiation.

2009-04-15  Hristian Kirtchev  <kirtchev@adacore.com>

	* a-calend.adb: Move constant Epoch_Offset from package
	Conversion_Operations to top level.
	(Delay_Operations.To_Duration): Define a constant which represents
	"end of time" and use it as a guard against very distant delay dates.
	Protect the code against overflow when performing the origin shift to
	Unix time.

From-SVN: r146095
This commit is contained in:
Arnaud Charlet 2009-04-15 11:57:47 +02:00
parent 361effb15b
commit 61bee0e370
3 changed files with 52 additions and 10 deletions
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13
gcc/ada/ChangeLog
View File

@ -1,3 +1,16 @@
2009-04-15 Ed Schonberg <schonberg@adacore.com>
* sem_ch4.adb: improve error message on exponentiation.
2009-04-15 Hristian Kirtchev <kirtchev@adacore.com>
* a-calend.adb: Move constant Epoch_Offset from package
Conversion_Operations to top level.
(Delay_Operations.To_Duration): Define a constant which represents
"end of time" and use it as a guard against very distant delay dates.
Protect the code against overflow when performing the origin shift to
Unix time.
2009-04-15 Robert Dewar <dewar@adacore.com>
* sem_prag.adb: Minor reformatting.

35
gcc/ada/a-calend.adb
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@ -177,6 +177,10 @@ package body Ada.Calendar is
Unix_Min : constant Time_Rep :=
Ada_Low + Time_Rep (17 * 366 + 52 * 365) * Nanos_In_Day;
Epoch_Offset : constant Time_Rep := (136 * 365 + 44 * 366) * Nanos_In_Day;
-- The difference between 2150-1-1 UTC and 1970-1-1 UTC expressed in
-- nanoseconds. Note that year 2100 is non-leap.
Cumulative_Days_Before_Month :
constant array (Month_Number) of Natural :=
(0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334);
@ -765,11 +769,6 @@ package body Ada.Calendar is
package body Conversion_Operations is
Epoch_Offset : constant Time_Rep :=
(136 * 365 + 44 * 366) * Nanos_In_Day;
-- The difference between 2150-1-1 UTC and 1970-1-1 UTC expressed in
-- nanoseconds. Note that year 2100 is non-leap.
-----------------
-- To_Ada_Time --
-----------------
@ -972,6 +971,15 @@ package body Ada.Calendar is
-----------------
function To_Duration (Date : Time) return Duration is
pragma Unsuppress (Overflow_Check);
Safe_Ada_High : constant Time_Rep := Ada_High - Epoch_Offset;
-- This value represents a "safe" end of time. In order to perform a
-- proper conversion to Unix duration, we will have to shift origins
-- at one point. For very distant dates, this means an overflow check
-- failure. To prevent this, the function returns the "safe" end of
-- time (roughly 2219) which is still distant enough.
Elapsed_Leaps : Natural;
Next_Leap_N : Time_Rep;
Res_N : Time_Rep;
@ -979,8 +987,8 @@ package body Ada.Calendar is
begin
Res_N := Time_Rep (Date);
-- If the target supports leap seconds, remove any leap seconds
-- elapsed up to the input date.
-- Step 1: If the target supports leap seconds, remove any leap
-- seconds elapsed up to the input date.
if Leap_Support then
Cumulative_Leap_Seconds
@ -1000,10 +1008,17 @@ package body Ada.Calendar is
Res_N := Res_N - Time_Rep (Elapsed_Leaps) * Nano;
-- Perform a shift in origins, note that enforcing type Time on
-- both operands will invoke Ada.Calendar."-".
-- Step 2: Perform a shift in origins to obtain a Unix equivalent of
-- the input. Guard against very large delay values such as the end
-- of time since the computation will overflow.
return Time (Res_N) - Time (Unix_Min);
if Res_N > Safe_Ada_High then
Res_N := Safe_Ada_High;
else
Res_N := Res_N + Epoch_Offset;
end if;
return Time_Rep_To_Duration (Res_N);
end To_Duration;
end Delay_Operations;

14
gcc/ada/sem_ch4.adb
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@ -5213,6 +5213,20 @@ package body Sem_Ch4 is
Error_Msg_N ("access parameter is not allowed to be null", L);
Error_Msg_N ("\(call would raise Constraint_Error)", L);
return;
-- Another special case for exponentiation, where the right
-- operand must be Natural, independently of the base.
elsif Nkind (N) = N_Op_Expon
and then Is_Numeric_Type (Etype (L))
and then not Is_Overloaded (R)
and then
First_Subtype (Base_Type (Etype (R))) /= Standard_Integer
and then Base_Type (Etype (R)) /= Universal_Integer
then
Error_Msg_NE
("exponent must be of type Natural, found}", R, Etype (R));
return;
end if;
-- If we fall through then just give general message. Note that in