[Vm-dev] [commit][3673] Provide VM hooks for testing Integer
class in plugins
Eliot Miranda
eliot.miranda at gmail.com
Wed Apr 20 21:50:08 UTC 2016
Hi Nicolas, Hi All,
Nicolas, I'm going to have to roll this form of the change back. The
change ignores the versioning convention for the VirtualMachine struct in
sqVirtualMachine.[ch]. If you look at the code you see things like:
typedef struct VirtualMachine {
sqInt (*minorVersion)(void);
sqInt (*majorVersion)(void);
/* InterpreterProxy methodsFor: 'stack access' */
sqInt (*pop)(sqInt nItems);
sqInt (*popthenPush)(sqInt nItems, sqInt oop);
sqInt (*push)(sqInt object);
sqInt (*pushBool)(sqInt trueOrFalse);
sqInt (*pushFloat)(double f);
sqInt (*pushInteger)(sqInt integerValue);
double (*stackFloatValue)(sqInt offset);
sqInt (*stackIntegerValue)(sqInt offset);
sqInt (*stackObjectValue)(sqInt offset);
sqInt (*stackValue)(sqInt offset);
...
#if VM_PROXY_MINOR > 1
/* InterpreterProxy methodsFor: 'BitBlt support' */
sqInt (*loadBitBltFrom)(sqInt bbOop);
sqInt (*copyBits)(void);
sqInt (*copyBitsFromtoat)(sqInt leftX, sqInt rightX, sqInt yValue);
#endif
...
#if VM_PROXY_MINOR > 12 /* Spur */
sqInt (*isImmediate)(sqInt objOop);
sqInt (*characterObjectOf)(int charCode);
sqInt (*characterValueOf)(sqInt objOop);
sqInt (*isCharacterObject)(sqInt objOop);
sqInt (*isCharacterValue)(int charCode);
sqInt (*isPinned)(sqInt objOop);
sqInt (*pinObject)(sqInt objOop);
sqInt (*unpinObject)(sqInt objOop);
#endif
} VirtualMachine;
So the idea is that the struct is changed only by changing the version
number for the interface, and only adds new fields, and doesn't redefine
existing ones. The idea is that existing external plugins that use older
versions of the API all continue to work when loaded by VMs that support
newer versions, but that (of course) newer versions of plugins won;t work
with older VMs. The change above introduced new fields in the middle of
the struct which breaks existing plugins.
So in adding the new functions we want for the LargeIntegers plugin (and
potentially others), we have to tread carefully and we have at least two
choices.
The functions we want to add are
sqInt (*isKindOfInteger)(sqInt oop);
sqInt (*isLargeIntegerObject)(sqInt oop);
sqInt (*isLargePositiveIntegerObject)(sqInt oop);
sqInt (*isLargeNegativeIntegerObject)(sqInt oop);
or rather, in plugin code we want to be able to write
isKindOfInteger(foo)
etc.
So we can either create a new version of the VirtualMachine API and add
these functions at the end of the struct or we can try and implement them
in terms of the existing API. If we add them at the end of the struct it
looks like
#if VM_PROXY_MINOR > 13
sqInt (*isKindOfInteger)(sqInt oop);
sqInt (*isLargeIntegerObject)(sqInt oop);
sqInt (*isLargePositiveIntegerObject)(sqInt oop);
sqInt (*isLargeNegativeIntegerObject)(sqInt oop);
#endif
But since we have all the functions we need to implement them already we
don't need to dip this. my idea was to modify the plugin code generator to
use the internal VM API when compiling a plugin as internal against Spur,
but use the existing API for non-Spur or external plugins. The reason to
use the special version for Spur is that in Spur the class indices of
LargePositiveInteger and LargeNegativeInteger are known constants so we can
generate simple and efficient code. I thought we could get it to output
something like
#if SPURVM && defined(SQUEAK_BUILTIN_PLUGIN)
# define LargeNegativeIntegerClassIndex 32
# define LargePositiveIntegerClassIndex 33
extern sqInt classIndexOf(sqInt);
# define isKindOfInteger(oop) (isImmediate(oop) ? isIntegerObject(oop) :
(unsigned)(classIndexOf(oop) - LargeNegativeIntegerClassIndex) <= 1)
# define isLargeIntegerObject(oop) (!isImmediate(oop)
&& (unsigned)(classIndexOf(oop) - LargeNegativeIntegerClassIndex) <= 1)
# define isLargeNegativeIntegerObject(oop) (!isImmediate(oop) &&
classIndexOf(oop) == LargeNegativeIntegerClassIndex)
# define isLargePositiveIntegerObject(oop) (!isImmediate(oop) &&
classIndexOf(oop) == LargePositiveIntegerClassIndex)
#else
# define isLargeNegativeIntegerObject(oop) (fetchClassOf(oop) ==
LargeNegativeIntegerClassIndex)
# define isLargePositiveIntegerObject(oop) (fetchClassOf(oop) ==
LargePositiveIntegerClassIndex)
# define isLargeIntegerObject(oop) (isLargeNegativeIntegerObject(oop)
|| isLargePositiveIntegerObject(oop))
# define isKindOfInteger(oop) (isIntegerObject(oop)
|| isLargeNegativeIntegerObject(oop) || isLargePositiveIntegerObject(oop))
#endif
Does that make sense? Perhaps it's too tricky, but it's really nice /not/
to have to change the VirtualMachine API often.
On Tue, Apr 19, 2016 at 5:06 PM, <commits at squeakvm.org> wrote:
>
> Revision: 3673
> Author: nice
> Date: 2016-04-19 17:06:30 -0700 (Tue, 19 Apr 2016)
> Log Message:
> -----------
> Provide VM hooks for testing Integer class in plugins
>
> Modified Paths:
> --------------
> branches/Cog/platforms/Cross/vm/sqVirtualMachine.c
> branches/Cog/platforms/Cross/vm/sqVirtualMachine.h
>
> Modified: branches/Cog/platforms/Cross/vm/sqVirtualMachine.c
> ===================================================================
> --- branches/Cog/platforms/Cross/vm/sqVirtualMachine.c 2016-04-19
> 18:21:14 UTC (rev 3672)
> +++ branches/Cog/platforms/Cross/vm/sqVirtualMachine.c 2016-04-20
> 00:06:30 UTC (rev 3673)
> @@ -65,7 +65,11 @@
> sqInt isBytes(sqInt oop);
> sqInt isFloatObject(sqInt oop);
> sqInt isIndexable(sqInt oop);
> -sqInt isIntegerObject(sqInt objectPointer);
> +sqInt isKindOfInteger(sqInt oop);
> +sqInt isLargeIntegerObject(sqInt oop);
> +sqInt isLargePositiveIntegerObject(sqInt oop);
> +sqInt isLargeNegativeIntegerObject(sqInt oop);
> +sqInt isIntegerObject(sqInt oop);
> sqInt isIntegerValue(sqInt intValue);
> sqInt isPointers(sqInt oop);
> sqInt isWeak(sqInt oop);
> @@ -329,6 +333,10 @@
> VM->isBytes = isBytes;
> VM->isFloatObject = isFloatObject;
> VM->isIndexable = isIndexable;
> + VM->isKindOfInteger = isKindOfInteger;
> + VM->isLargeIntegerObject = isLargeIntegerObject;
> + VM->isLargePositiveIntegerObject = isLargePositiveIntegerObject;
> + VM->isLargeNegativeIntegerObject = isLargeNegativeIntegerObject;
> VM->isIntegerObject = isIntegerObject;
> VM->isIntegerValue = isIntegerValue;
> VM->isPointers = isPointers;
>
> Modified: branches/Cog/platforms/Cross/vm/sqVirtualMachine.h
> ===================================================================
> --- branches/Cog/platforms/Cross/vm/sqVirtualMachine.h 2016-04-19
> 18:21:14 UTC (rev 3672)
> +++ branches/Cog/platforms/Cross/vm/sqVirtualMachine.h 2016-04-20
> 00:06:30 UTC (rev 3673)
> @@ -111,7 +111,11 @@
> sqInt (*isBytes)(sqInt oop);
> sqInt (*isFloatObject)(sqInt oop);
> sqInt (*isIndexable)(sqInt oop);
> - sqInt (*isIntegerObject)(sqInt objectPointer);
> + sqInt (*isKindOfInteger)(sqInt oop);
> + sqInt (*isLargeIntegerObject)(sqInt oop);
> + sqInt (*isLargePositiveIntegerObject)(sqInt oop);
> + sqInt (*isLargeNegativeIntegerObject)(sqInt oop);
> + sqInt (*isIntegerObject)(sqInt oop);
> sqInt (*isIntegerValue)(sqInt intValue);
> sqInt (*isPointers)(sqInt oop);
> sqInt (*isWeak)(sqInt oop);
>
>
--
_,,,^..^,,,_
best, Eliot
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