Partials v2 gen #22

arnaud-lb · 2025-09-08T16:46:58Z

PFAs are created by generating the AST of a Closure at runtime and compiling it. The compiled op_array can be cached similarly to linked classes.

About caching

There are two levels of caching:

The global opcache (ZCG(hash))
The caller's run time cache

The cache key in ZCG(hash) is composed of the address of the declaring opline, the address of the function being called, and a prefix.

This scheme is not ideal because:

The key used in ZCG(hash) may be a valid file name (Edit: This is avoided by prefixing the name with a URL scheme, like pfa://)
This takes a slot in ZCG(hash)
When opcache is not enabled, only the run time cache is used. This cache stores only one entry, so cache misses will occur when the function being called changes.

A better solution might be to cache PFA op_arrays in the declaring op_array (similarly, the inheritance cache is stored in classes). This cache could store multiple PFAs, and could be used regardless of opcache being enabled.

Alternatively, use a global two-level map: First level is indexed by the "signature" of the PFA, second level by the function being called. This would lead to a better cache hit rate when the same function is partialled in multiple locations.

TODO

Zend/tests/partial_application/errors_001.phpt

Zend/tests/partial_application/clone.phpt

Zend/tests/partial_application/compile_errors_001.phpt

TimWolla · 2025-11-03T17:14:50Z

Zend/tests/partial_application/errors_001.phpt

Can we get a test case where the function has optional arguments and an incorrect number is given (just to see the error message once).

This test shows this error message: https://github.com/arnaud-lb/php-src/blob/75dbd22353d81d34d63587f9c703523f5d10b82e/Zend/tests/partial_application/rfc_examples_003.phpt
Do you prefer a dedicated test case?

Great, I just realize that the error messages for userland and native functions are already inconsistent with each other:

https://3v4l.org/3G8EO

Zend/tests/partial_application/variation_invoke_001.phpt

Zend/tests/partial_application/variation_nocall_002.phpt

Zend/zend_ast.c

Zend/tests/partial_application/references_001.phpt

Zend/tests/partial_application/this_001.phpt

Zend/tests/partial_application/variation_ex_001.phpt

Zend/tests/partial_application/superfluous_args_are_forwarded.phpt

Zend/zend_object_handlers.c

TimWolla · 2025-11-18T15:40:19Z

Zend/zend_execute.c

+ZEND_API bool zend_check_type_ex(
+		const zend_type *type, zval *arg, zend_class_entry *scope,
+		bool is_return_type, bool is_internal)
+{
+	return zend_check_type(type, arg, scope, is_return_type, is_internal);
+}


What's the purpose of this? Wouldn't it work to expose zend_check_type() directly?

It's not that easy, as the function is always_inline, and uses always_inline functions from this file as well. zend_check_type() is critical, I didn't want to take the risk of performance regression.

So we have the following options:

Move the function and a bunch of functions it uses to a header file (zend_check_type, zend_check_type_slow, zend_check_intersection_type_from_list, probably others), so we don't lose inline-ability

Make the function extern inline, but we don't do that (there was a thread about that in a PR).

Export a wrapper, like I did here

I will think about about the other options

Zend/tests/partial_application/reflection_005.phpt

ext/opcache/ZendAccelerator.c

Co-authored-by: Joe Watkins <[email protected]>

Co-authored-by: Tim Düsterhus <[email protected]>

* We can't handle the variadic placeholder like non-variadic ones, as the slot may be occupied by a named arg. * Using Z_EXTRA(arg0) works, but it's uninitialized unless we set it in all SEND_PLACEHOLDER ops.

TimWolla · 2025-12-15T21:35:50Z

Zend/tests/partial_application/fuzz_003.phpt

+    }
+}
+$foo = new Foo;
+$bar = $foo->method(1,...);


Suggested change

$bar = $foo->method(1,...);

$bar = $foo->method(1, ...);

TimWolla · 2025-12-15T21:36:22Z

Zend/tests/partial_application/fuzz_004.phpt

+try {
+    $foo->__invoke(UNDEFINED);
+} catch (\Throwable $e) {
+    echo $e->getMessage(), "\n";


Suggested change

echo $e->getMessage(), "\n";

echo $e::class, ": ", $e->getMessage(), "\n";

TimWolla · 2025-12-15T21:38:52Z

Zend/tests/partial_application/reflection_004.phpt

@@ -0,0 +1,13 @@
+--TEST--
+Closure application reflection: ReflectionFunction::isClosure() is true for partials


What's the difference with the reflection_005 one? Also, should we have a test for isAnonymous?

TimWolla · 2025-12-15T21:41:21Z

Zend/tests/partial_application/rfc_examples_010.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Closure application RFC examples: delayed execution


I'm not sure if this test is actually properly showing the delayed execution, since there are pretty much no side effects. expensive() should probably print something and then there should also be something printed right before the if() or so.

arnaud-lb force-pushed the partials-v2-gen branch 3 times, most recently from 7062e66 to f65bf45 Compare September 13, 2025 10:37

TimWolla reviewed Oct 3, 2025

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arnaud-lb force-pushed the partials-v2-gen branch 2 times, most recently from d820a4f to 75dbd22 Compare November 3, 2025 17:04

TimWolla reviewed Nov 3, 2025

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arnaud-lb force-pushed the partials-v2-gen branch 2 times, most recently from bf4b4f6 to b753b0c Compare November 3, 2025 18:55

TimWolla reviewed Nov 3, 2025

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TimWolla reviewed Nov 18, 2025

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arnaud-lb and others added 17 commits December 10, 2025 14:23

Partial application

d09a2d9

Co-authored-by: Joe Watkins <[email protected]>

Generate static closure when possible. Use static:: for static methods.

14f2785

Fix tests

05dc35f

Use only function as cache key. Fix inline cache.

681a16d

Fix jit

8272d0a

Restore bindTo() rules (TODO: rebind internal closure)

bc83254

Reorganize zend_partial_create / zp_compile

0662e9f

Fix arg

e743cca

Use arena

89aa494

Fix pass-by-ref variadic

48206bd

Simplify

e580f86

Remove trailing new line in tests

a3588ed

Print exception class

be2689e

Update Zend/tests/partial_application/clone.phpt

7f8cfd4

Co-authored-by: Tim Düsterhus <[email protected]>

Fix tests when opcache is not enabled

baf9dc5

Fix mem leak when opcache is not enabled

b9ec575

Fix UAF when opcache is not enabled

b969160

arnaud-lb added 20 commits December 10, 2025 14:24

Prevent opcache collisions

7e6b3c0

Non-shm second-level cache

178af8e

Comment

87aa642

Record warnings

88639b0

bindTo() rebinds inner closure

cef7164

Remove duplicated code

40bce06

Do not allow PFA of func_get_arg(), compact(), extract()

6a98cbd

assert() special case

0d85620

Error handling

56d7804

Fix caching

6f7918b

Fix test

1f3d25e

Merge ZEND_CHECK_PARTIAL_ARGS with ZEND_CALLABLE_CONVERT_PARTIAL

8d5f138

Handle attributes for variadic placeholder

86c656e

Cleanup

b3ad9d6

Init zend_call_trampoline_arginfo in MINIT

0332e6f

Improve how the variadic placeholder is passed

178c3e3

* We can't handle the variadic placeholder like non-variadic ones, as the slot may be occupied by a named arg. * Using Z_EXTRA(arg0) works, but it's uninitialized unless we set it in all SEND_PLACEHOLDER ops.

Resetting fbc is not necessary

f220277

Fix arg count check when a variadic placeholder exists

b9111b7

Fix memcpy size

a947111

Fix ZEND_CALLABLE_CONVERT_PARTIAL meta

65a21f2

arnaud-lb force-pushed the partials-v2-gen branch from 5b8cfc2 to 65a21f2 Compare December 10, 2025 17:20

arnaud-lb added 3 commits December 10, 2025 18:21

Generated files

0a8f791

Remove zend_partial_symbol_name()

66c3cfd

Cleanup

788e916

arnaud-lb changed the base branch from master to tmp-master December 10, 2025 17:35

arnaud-lb changed the base branch from tmp-master to master December 10, 2025 17:35

arnaud-lb added 3 commits December 10, 2025 18:39

Missing case

90d18e8

Cleanup

565372d

Fix test

e1a4016

TimWolla reviewed Dec 15, 2025

View reviewed changes

	echo $e->getMessage(), "\n";
	echo $e::class, ": ", $e->getMessage(), "\n";

		@@ -0,0 +1,13 @@
		--TEST--
		Closure application reflection: ReflectionFunction::isClosure() is true for partials

		@@ -0,0 +1,24 @@
		--TEST--
		Closure application RFC examples: delayed execution

Partials v2 gen #22

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Partials v2 gen #22

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arnaud-lb commented Sep 8, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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About caching

TODO

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arnaud-lb commented Sep 8, 2025 •

edited

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