function Set_Stack_Info
(Stack : not null access Stack_Access) return Stack_Access;
- -- The function Set_Stack_Info is the actual function that updates
- -- the cache containing a pointer to the Stack_Info. It may also
- -- be used for detecting asynchronous abort in combination with
- -- Invalidate_Self_Cache.
+ -- The function Set_Stack_Info is the actual function that updates the
+ -- cache containing a pointer to the Stack_Info. It may also be used for
+ -- detecting asynchronous abort in combination with Invalidate_Self_Cache.
-- Set_Stack_Info should do the following things in order:
-- 1) Get the Stack_Access value for the current task
-- 2) Set Stack.all to the value obtained in 1)
-- 3) Optionally Poll to check for asynchronous abort
- -- This order is important because if at any time a write to
- -- the stack cache is pending, that write should be followed
- -- by a Poll to prevent loosing signals.
+ -- This order is important because if at any time a write to the stack
+ -- cache is pending, that write should be followed by a Poll to prevent
+ -- loosing signals.
-- Note: This function must be compiled with Polling turned off
if My_Stack.Base = Null_Address then
- -- First invocation, initialize based on the assumption that
- -- there are Environment_Stack_Size bytes available beyond
- -- the current frame address.
+ -- First invocation, initialize based on the assumption that there
+ -- are Environment_Stack_Size bytes available beyond the current
+ -- frame address.
if My_Stack.Size = 0 then
My_Stack.Size := Storage_Offset (Default_Env_Stack_Size);
- -- When the environment variable GNAT_STACK_LIMIT is set,
- -- set Environment_Stack_Size to that number of kB.
+ -- When the environment variable GNAT_STACK_LIMIT is set, set
+ -- Environment_Stack_Size to that number of kB.
Limit_Chars := System.CRTL.getenv ("GNAT_STACK_LIMIT" & ASCII.NUL);
end if;
end if;
- -- If a stack base address has been registered, honor it.
- -- Fallback to the address of a local object otherwise.
+ -- If a stack base address has been registered, honor it. Fallback to
+ -- the address of a local object otherwise.
if My_Stack.Limit /= System.Null_Address then
My_Stack.Base := My_Stack.Limit;
raise Standard'Abort_Signal;
end if;
- return My_Stack; -- Never trust the cached value, but return local copy!
+ -- Never trust the cached value, but return local copy!
+
+ return My_Stack;
end Set_Stack_Info;
-----------------
raise Storage_Error with "stack overflow detected";
end if;
- -- This function first does a "cheap" check which is correct
- -- if it succeeds. In case of failure, the full check is done.
- -- Ideally the cheap check should be done in an optimized manner,
- -- or be inlined.
+ -- This function first does a "cheap" check which is correct if it
+ -- succeeds. In case of failure, the full check is done. Ideally the
+ -- cheap check should be done in an optimized manner, or be inlined.
if (Stack_Grows_Down and then
(Frame_Address <= Cached_Stack.Base
- and
+ and then
Stack_Address > Cached_Stack.Limit))
or else
(not Stack_Grows_Down and then
(Frame_Address >= Cached_Stack.Base
- and
+ and then
Stack_Address < Cached_Stack.Limit))
then
-- Cached_Stack is valid as it passed the stack check
+
return Cached_Stack;
end if;
(not Stack_Grows_Down and then
(not (Frame_Address >= My_Stack.Base)))
then
- -- The returned Base is lower than the stored one,
- -- so assume that the original one wasn't right and use the
- -- current Frame_Address as new one. This allows initializing
- -- Base with the Frame_Address as approximation.
- -- During initialization the Frame_Address will be close to
- -- the stack base anyway: the difference should be compensated
- -- for in the stack reserve.
+ -- The returned Base is lower than the stored one, so assume that
+ -- the original one wasn't right and use the current Frame_Address
+ -- as new one. This allows Base to be initialized with the
+ -- Frame_Address as approximation. During initialization the
+ -- Frame_Address will be close to the stack base anyway: the
+ -- difference should be compensated for in the stack reserve.
My_Stack.Base := Frame_Address;
end if;
- if (Stack_Grows_Down and then
- Stack_Address < My_Stack.Limit)
+ if (Stack_Grows_Down
+ and then Stack_Address < My_Stack.Limit)
or else
- (not Stack_Grows_Down and then
- Stack_Address > My_Stack.Limit)
+ (not Stack_Grows_Down
+ and then Stack_Address > My_Stack.Limit)
then
raise Storage_Error with "stack overflow detected";
end if;
OSDN Git Service
