Description

markshannon

opened on Aug 15, 2024

Issue body actions

This applies to both instances and classes.
If an object and it's class both have attributes with the same name, this prevents specialization of access to the object's attribute.
However, in this case specialization should only be prevented if the class's attribute is a data descriptor.

Example 1, instance:

class C:
    x = 1
    def __init__(self):
        self.x = 2

C().x

C().x above is 2. It doesn't matter that C.x exists, provided it isn't a data descriptor.
This failure shows up as "shadowed" in the stats

Example 2, class:

class Meta(type):
    x = 1
class C(metaclass=Meta):
    x = 1

C.x

C.x is 2. Meta.x doesn't change that, as it isn't a data descriptor.
This failure shows up as "metaclass attribute" in the stats

Linked PRs

• GH-123040: Specialize shadowed LOAD_ATTR. #123219

Activity

1. markshannon commented on Aug 15, 2024

   

   markshannon

   on Aug 15, 2024

   MemberAuthor

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   For STORE_ATTR, the failures show up in various ways, depending on the nature of the class's attribute.
2. markshannon

   changed the title [-]Unnecessary specialization failures of `LOAD_ATTR` and `STORE_ATTR` when attributes are shadowed by the object' class.[/-] [+]Unnecessary specialization failures of `LOAD_ATTR` and `STORE_ATTR` when attributes are shadowed by the object's class.[/+] on Aug 15, 2024
3. picnixz

   added

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   on Aug 16, 2024
4. picnixz commented on Aug 16, 2024

   

   picnixz

   on Aug 16, 2024

   Member

   More actions

   Should this one be categorized as a bug or a feature (AFAICT, it's not really a bug per se, it's just an inefficient path being taken)?
5. markshannon

   added

   performancePerformance or resource usagePerformance or resource usage

   on Aug 16, 2024
6. markshannon commented on Aug 16, 2024

   

   markshannon

   on Aug 16, 2024

   MemberAuthor

   More actions

   I'll just tag it "performance"

   Reacted by Bénédikt Tran
7. markshannon

   added

   3.14bugs and security fixesbugs and security fixes

   on Aug 16, 2024
8. markshannon

   added a commit that references this issue on Aug 23, 2024

   GH-123040: Specialize shadowed `LOAD_ATTR`. (GH-123219)

   5d3201f
9. markshannon

   closed this as completedon Aug 23, 2024

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