diff options
Diffstat (limited to 'lang/gnat/files/5fsystem.ads')
| -rw-r--r-- | lang/gnat/files/5fsystem.ads | 171 |
1 files changed, 34 insertions, 137 deletions
diff --git a/lang/gnat/files/5fsystem.ads b/lang/gnat/files/5fsystem.ads index f4c1192b1981..e7fb766e44bb 100644 --- a/lang/gnat/files/5fsystem.ads +++ b/lang/gnat/files/5fsystem.ads @@ -60,16 +60,16 @@ pragma Pure (System); Max_Mantissa : constant := 63; Fine_Delta : constant := 2.0 ** (-Max_Mantissa); - Tick : constant := Standard'Tick; + Tick : constant := 1.0; -- Storage-related Declarations type Address is private; Null_Address : constant Address; - Storage_Unit : constant := Standard'Storage_Unit; - Word_Size : constant := Standard'Word_Size; - Memory_Size : constant := 2 ** Standard'Address_Size; + Storage_Unit : constant := 8; + Word_Size : constant := 32; + Memory_Size : constant := 2 ** 32; -- Address comparison @@ -88,32 +88,18 @@ pragma Pure (System); -- Other System-Dependent Declarations type Bit_Order is (High_Order_First, Low_Order_First); - Default_Bit_Order : constant Bit_Order := - Bit_Order'Val (Standard'Default_Bit_Order); + Default_Bit_Order : constant Bit_Order := Low_Order_First; -- Priority-related Declarations (RM D.1) - Max_Priority : constant Positive := 30; - + Max_Priority : constant Positive := 30; Max_Interrupt_Priority : constant Positive := 31; - subtype Any_Priority is Integer - range 0 .. Standard'Max_Interrupt_Priority; - - subtype Priority is Any_Priority - range 0 .. Standard'Max_Priority; - - -- Functional notation is needed in the following to avoid visibility - -- problems when this package is compiled through rtsfind in the middle - -- of another compilation. + subtype Any_Priority is Integer range 0 .. 31; + subtype Priority is Any_Priority range 0 .. 30; + subtype Interrupt_Priority is Any_Priority range 31 .. 31; - subtype Interrupt_Priority is Any_Priority - range - Standard."+" (Standard'Max_Priority, 1) .. - Standard'Max_Interrupt_Priority; - - Default_Priority : constant Priority := - Standard."/" (Standard."+" (Priority'First, Priority'Last), 2); + Default_Priority : constant Priority := 15; private @@ -126,117 +112,28 @@ private -- These parameters provide information about the target that is used -- by the compiler. They are in the private part of System, where they - -- can be accessed using Rtsfind. All values defined here must be - -- constants, since they are accessed at compile time. - - -- Note these definitions must come before the definitions of any - -- complex types or other code that may require Rtsfind to access - -- these entities during compilation of System itself. - - ----------------------------------- - -- Control of Exception Handling -- - ----------------------------------- - - -- GNAT provides two methods of implementing exceptions: - - -- Longjmp/Setjmp (-gnatL) - - -- This approach uses longjmp/setjmp to handle exceptions. It - -- uses less storage, and can often propagate exceptions faster, - -- at the expense of (sometimes considerable) overhead in setting - -- up an exception handler. This approach is available on all - -- targets, and is the default where it is the only approach. - - -- Zero Cost (-gnatZ) - - -- This approach uses separate exception tables. These use extra - -- storage, and exception propagation can be quite slow, but there - -- is no overhead in setting up an exception handler (it is to this - -- latter operation that the phrase zero-cost refers). This approach - -- is only available on some targets, and is the default where it is - -- available. - - Zero_Cost_Exceptions : constant Boolean := False; - -- Set False for Longjmp/Setjmp, True for Zero Cost - - ------------------------------- - -- Control of Stack Checking -- - ------------------------------- - - -- GNAT provides two methods of implementing exceptions: - - -- GCC Probing Mechanism - - -- This approach uses the standard GCC mechanism for - -- stack checking. The method assumes that accessing - -- storage immediately beyond the end of the stack - -- will result in a trap that is converted to a storage - -- error by the runtime system. This mechanism has - -- minimal overhead, but requires complex hardware, - -- operating system and run-time support. Probing is - -- the default method where it is available. The stack - -- size for the environment task depends on the operating - -- system and cannot be set in a system-independent way. - - -- GNAT Stack-limit Checking - - -- This method relies on comparing the stack pointer - -- with per-task stack limits. If the check fails, an - -- exception is explicitly raised. The advantage is - -- that the method requires no extra system dependent - -- runtime support and can be used on systems without - -- memory protection as well, but at the cost of more - -- overhead for doing the check. This method is the - -- default on systems that lack complete support for - -- probing. - - Stack_Check_Probes : constant Boolean := True; - -- Set True for GCC Probing, False for GNAT Stack-limit Checking - - Stack_Check_Default : constant Boolean := True; - -- Set True for systems where stack checking is performed by default - - ---------------------------------------------- - -- Boolean-Valued Floating-Point Attributes -- - ---------------------------------------------- - - -- The constants below give the values for representation oriented - -- floating-point attributes that are the same for all float types - -- on the target. These are all boolean values. - - -- A value is only True if the target reliably supports the corresponding - -- feature. Reliably here means that support is guaranteed for all - -- possible settings of the relevant compiler switches (like -mieee), - -- since we cannot control the user setting of those switches. - - -- The attributes cannot dependent on the current setting of compiler - -- switches, since the values must be static and consistent throughout - -- the partition. We probably should add such consistency checks in future, - -- but for now we don't do this. - - Denorm : constant Boolean := True; - - Machine_Rounds : constant Boolean := True; - - Machine_Overflows : constant Boolean := False; - - Signed_Zeros : constant Boolean := True; - - ---------------------------- - -- Support of Long Shifts -- - ---------------------------- - - -- In GNORT mode, we cannot call library routines, and in particular - -- we cannot call routines for long (64-bit) shifts if such routines - -- are required on the target. This comes up in the context of support - -- of packed arrays. We can only represent packed arrays whose length - -- is in the range 33- to 64-bits as modular types if long shifts are - -- done with inline code. - - -- For the default version, for now we set long shifts inlined as True - -- This may not be quite accurate, but until we get proper separate - -- System's for each target, it is a safer choice. - - Long_Shifts_Inlined : constant Boolean := True; - + -- can be accessed using the special circuitry in the Targparm unit + -- whose source should be consulted for more detailed descriptions + -- of the individual switch values. + + AAMP : constant Boolean := False; + Backend_Divide_Checks : constant Boolean := False; + Backend_Overflow_Checks : constant Boolean := False; + Command_Line_Args : constant Boolean := True; + Denorm : constant Boolean := True; + Fractional_Fixed_Ops : constant Boolean := False; + Frontend_Layout : constant Boolean := False; + Functions_Return_By_DSP : constant Boolean := False; + Long_Shifts_Inlined : constant Boolean := True; + High_Integrity_Mode : constant Boolean := False; + Machine_Overflows : constant Boolean := False; + Machine_Rounds : constant Boolean := True; + OpenVMS : constant Boolean := False; + Signed_Zeros : constant Boolean := True; + Stack_Check_Default : constant Boolean := False; + Stack_Check_Probes : constant Boolean := False; + Use_Ada_Main_Program_Name : constant Boolean := False; + ZCX_By_Default : constant Boolean := False; + GCC_ZCX_Support : constant Boolean := False; + Front_End_ZCX_Support : constant Boolean := False; end System; |