Is there a mechanism by which we can declare code to be eliminated when compiling with (declare (not safe))? I haven't been able to find anything, and it would be very nice to have something like (when-declare (safe) stuff ...), which would be eliminated in unsafe compilation. The context is that I want to add a contract system to Gerbil, but I don't want the runtime checks to persist when compiling with (not safe).
-- vyzo
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Just a follow up:
It is possible to do it with a cond-expand, as the gerbil compiler can detect when it is compiling with (not safe). The contract check in the generated code would be at the function entry point and look like: (cond-expand (gerbil-runtime-checks ...) ;; do checks and raise exception if the contract is violated (else))
When the compiler detects that it is in a safe context (absence of a local or prelude (not safe) declaration), then it can emit a (define-cond-expand-feature|gerbil-runtime-checks|) for gsc, and compile in the contract checks.
This is a reasonably good solution, so there is no pressing need to add a construct to gambit that conditionally compiles based on declarations.
-- vyzo
On Tue, Nov 26, 2019 at 8:39 PM Dimitris Vyzovitis vyzo@hackzen.org wrote:
Is there a mechanism by which we can declare code to be eliminated when compiling with (declare (not safe))? I haven't been able to find anything, and it would be very nice to have something like (when-declare (safe) stuff ...), which would be eliminated in unsafe compilation. The context is that I want to add a contract system to Gerbil, but I don't want the runtime checks to persist when compiling with (not safe).
-- vyzo
I was going to suggest using the cond-expand approach.
Also, it might be interesting for the compiler to make the current declarations testable as cond-expand features. Giving something like:
(cond-expand ((declare (not safe)) …) ((declare (debug)) …) ((declare (optimize-dead-definitions)) …) (else …))
The implementation of this is complicated by the fact that the interpreter and compiler don’t manage declarations the same way.
Marc
On Nov 27, 2019, at 9:10 AM, Dimitris Vyzovitis vyzo@hackzen.org wrote:
Just a follow up:
It is possible to do it with a cond-expand, as the gerbil compiler can detect when it is compiling with (not safe). The contract check in the generated code would be at the function entry point and look like: (cond-expand (gerbil-runtime-checks ...) ;; do checks and raise exception if the contract is violated (else))
When the compiler detects that it is in a safe context (absence of a local or prelude (not safe) declaration), then it can emit a (define-cond-expand-feature|gerbil-runtime-checks|) for gsc, and compile in the contract checks.
This is a reasonably good solution, so there is no pressing need to add a construct to gambit that conditionally compiles based on declarations.
-- vyzo
On Tue, Nov 26, 2019 at 8:39 PM Dimitris Vyzovitis vyzo@hackzen.org wrote: Is there a mechanism by which we can declare code to be eliminated when compiling with (declare (not safe))? I haven't been able to find anything, and it would be very nice to have something like (when-declare (safe) stuff ...), which would be eliminated in unsafe compilation. The context is that I want to add a contract system to Gerbil, but I don't want the runtime checks to persist when compiling with (not safe).
-- vyzo
That would be a pretty awesome feature!
-- vyzo
On Wed, Nov 27, 2019 at 4:42 PM Marc Feeley feeley@iro.umontreal.ca wrote:
I was going to suggest using the cond-expand approach.
Also, it might be interesting for the compiler to make the current declarations testable as cond-expand features. Giving something like:
(cond-expand ((declare (not safe)) …) ((declare (debug)) …) ((declare (optimize-dead-definitions)) …) (else …))
The implementation of this is complicated by the fact that the interpreter and compiler don’t manage declarations the same way.
Marc
On Nov 27, 2019, at 9:10 AM, Dimitris Vyzovitis vyzo@hackzen.org
wrote:
Just a follow up:
It is possible to do it with a cond-expand, as the gerbil compiler can
detect when it is compiling with (not safe).
The contract check in the generated code would be at the function entry
point and look like:
(cond-expand (gerbil-runtime-checks ...) ;; do checks and raise exception if the contract is violated (else))
When the compiler detects that it is in a safe context (absence of a
local or prelude (not safe) declaration), then it
can emit a (define-cond-expand-feature|gerbil-runtime-checks|) for gsc,
and compile in the contract checks.
This is a reasonably good solution, so there is no pressing need to add
a construct to gambit that conditionally compiles based on declarations.
-- vyzo
On Tue, Nov 26, 2019 at 8:39 PM Dimitris Vyzovitis vyzo@hackzen.org
wrote:
Is there a mechanism by which we can declare code to be eliminated when
compiling with (declare (not safe))?
I haven't been able to find anything, and it would be very nice to have
something like (when-declare (safe) stuff ...),
which would be eliminated in unsafe compilation. The context is that I want to add a contract system to Gerbil, but I
don't want the runtime checks to persist when
compiling with (not safe).
-- vyzo
On Nov 27, 2019, at 9:10 AM, Dimitris Vyzovitis vyzo@hackzen.org wrote:
When the compiler detects that it is in a safe context (absence of a local or prelude (not safe) declaration), then it can emit a (define-cond-expand-feature|gerbil-runtime-checks|) for gsc, and compile in the contract checks.
BTW I don’t think you should conflate the presence of a (not safe) declaration and avoiding contract checks. The two are closely related, but maybe you want finer control to disable them separately.
Marc
Good point. This is all achievable with the cond-expand approach, the compiler can accept a flag to explicitly disable contract checks.
-- vyzo
On Wed, Nov 27, 2019 at 4:45 PM Marc Feeley feeley@iro.umontreal.ca wrote:
On Nov 27, 2019, at 9:10 AM, Dimitris Vyzovitis vyzo@hackzen.org
wrote:
When the compiler detects that it is in a safe context (absence of a
local or prelude (not safe) declaration), then it
can emit a (define-cond-expand-feature|gerbil-runtime-checks|) for gsc,
and compile in the contract checks.
BTW I don’t think you should conflate the presence of a (not safe) declaration and avoiding contract checks. The two are closely related, but maybe you want finer control to disable them separately.
Marc
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Dimitris Vyzovitis -
Marc Feeley