feat[lang]: allow module intrinsic interface call

[charles-cooper]

allow module.__interface__ to be used in call position by adding it to the module membership data structure.

additionally, fix a bug where interfaces defined inline could not be exported. this is simultaneously fixed as a related bug because previously, interfaces could come up in export analysis as InterfaceT or TYPE_T depending on their provenance. this commit fixes the bug by making them TYPE_T in both imported and inlined provenance.

refactor:

• wrap interfaces in TYPE_T
• streamline an isinstance(t, (VyperType, TYPE_T)) check. TYPE_T now inherits from VyperType, so it doesn't need to be listed separately

What I did

fixes https://github.com/vyperlang/vyper/issues/3943

How I did it

How to verify it

Commit message

Commit message for the final, squashed PR. (Optional, but reviewers will appreciate it! Please see our commit message style guide for what we would ideally like to see in a commit message.)

Description for the changelog

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[cyberthirst]

we allow for exporting a module with no external functions - i think we should raise in such case:

# main.vy
import lib1

def f(x: Bytes[32*5]) -> uint256:
     k: uint256 = lib1.foo()
     return k


exports: lib1.__interface__

# lib1.vy
@internal
def foo() -> uint256:
    return 1

[cyberthirst]

import lib1

uses: lib1

@deploy
def __init__():
    lib1.__interface__(self).__init__()


exports: lib1.__interface__

#lib1.vy
k: uint256

@external
def bar():
    pass

@deploy
def __init__():
    self.k = 10

AttributeError: 'NoneType' object has no attribute 'module_t'

[cyberthirst]

__interface__ can be used in "weird positions:

main.vy
import lib1

#uses: lib1

@deploy
def __init__():
    log lib1.__interface__.Foo(1)
    s: lib1.Structt = lib1.__interface__.Structt(i=1)


exports: lib1.__interface__

#lib1.vy
event Foo:
    i: uint256

struct Structt:
    i: uint256

k: uint256

@external
def bar():
    pass

@deploy
def __init__():
    self.k = 10

[cyberthirst]

should address https://github.com/vyperlang/vyper/issues/3943, right?

[cyberthirst]

with -f annotated_ast i get:

AttributeError: 'FunctionDef' object has no attribute 'node_id'

# main.vy
import lib1

@external
def foo() -> uint256:
    return staticcall lib1.__interface__(self).d()
# lib1.vy
d: public(uint256)

[fubuloubu]

would it be too much to ask for implicit cast of mod to mod.__interface__? For either v: Mod in argument (convert to Interface to use like v.method(...)) or extcall Mod(v).method(...)

.__interface__ is a little awkward to specify

[charles-cooper]

with -f annotated_ast i get:

AttributeError: 'FunctionDef' object has no attribute 'node_id'

# main.vy
import lib1

@external
def foo() -> uint256:
    return staticcall lib1.__interface__(self).d()
# lib1.vy
d: public(uint256)

on latest (96213973ed07c584436ac9291b60061473649817) we get:

vyper.exceptions.UnknownAttribute: tmp/lib1.vy has no member 'd'.

  contract "tmp/main.vy:6", function "foo", line 6:22 
       5 def foo() -> uint256:
  ---> 6     return staticcall lib1.__interface__(self).d()
  -----------------------------^
       7

[charles-cooper]

would it be too much to ask for implicit cast of mod to mod.__interface__? For either v: Mod in argument (convert to Interface to use like v.method(...)) or extcall Mod(v).method(...)

.__interface__ is a little awkward to specify

yes but it's a bit hairy. it will feel ambiguous once we add deploy Mod(...) syntax

[charles-cooper]

we allow for exporting a module with no external functions - i think we should raise in such case:

# main.vy
import lib1

def f(x: Bytes[32*5]) -> uint256:
     k: uint256 = lib1.foo()
     return k


exports: lib1.__interface__

# lib1.vy
@internal
def foo() -> uint256:
    return 1

24ac428539955f272a08e49301fbd8107d30b048

[charles-cooper]

should address #3943, right?

yes. updated the PR description

[charles-cooper]

with -f annotated_ast i get:

AttributeError: 'FunctionDef' object has no attribute 'node_id'

# main.vy
import lib1

@external
def foo() -> uint256:
    return staticcall lib1.__interface__(self).d()
# lib1.vy
d: public(uint256)

should be fixed as of latest (24ac428539955f272a08e49301fbd8107d30b048)

[charles-cooper]

__interface__ can be used in "weird positions:

main.vy
import lib1

#uses: lib1

@deploy
def __init__():
    log lib1.__interface__.Foo(1)
    s: lib1.Structt = lib1.__interface__.Structt(i=1)


exports: lib1.__interface__

#lib1.vy
event Foo:
    i: uint256

struct Structt:
    i: uint256

k: uint256

@external
def bar():
    pass

@deploy
def __init__():
    self.k = 10

i'm not too bothered. it looks a bit weird, but technically Structt is a member of the interface. are you suggesting we should block it and only allow using lib1.__interface__.<external function>?

[cyberthirst]

a bit oos for this PR, but we allow for implements: I where I is an empty .vyi file - which most likely is a bug in the user code

[cyberthirst]

for code like

# main.vy
import lib1

implements: lib1. __interface__

i get:

vyper.exceptions.UnknownAttribute: tests/custom/lib1.vy has no member '__interface__'.

  contract "tests/custom/test4.vy:4", line 4:12 
       3
  ---> 4 implements: lib1. __interface__
  -------------------^
       5

which is weird given we allow

# main.vy
import lib1

exports: lib1. __interface__

EDIT: i must have made a mistake during branch switching - i was cross-checking the behavior also against master and I can't repro this against this branch

[cyberthirst]

# main.vy
import ITest2

exports: ITest2

# ITest2.vyi
def foo() -> uint8:
    ...
@view
def foobar() -> uint8:
    ...

yields:

Error compiling: tests/custom/test4.vy
vyper.exceptions.StructureException: not a function or interface: `type(tests/custom/ITest2.vyi)`

  contract "tests/custom/test4.vy:4", line 4:9 
       3
  ---> 4 exports: ITest2
  ----------------^
       5

EDIT: i must have made a mistake during branch switching - i was cross-checking the behavior also against master and I can't repro this against this branch

[cyberthirst]

i'm not too bothered. it looks a bit weird, but technically Structt is a member of the interface. are you suggesting we should block it and only allow using lib1.__interface__.<external function>?

yes, that was the original intention

however, as i test it, the poc now doesn't work. is this intentional?

[charles-cooper]

for code like

# main.vy
import lib1

implements: lib1. __interface__

i get:

vyper.exceptions.UnknownAttribute: tests/custom/lib1.vy has no member '__interface__'.

  contract "tests/custom/test4.vy:4", line 4:12 
       3
  ---> 4 implements: lib1. __interface__
  -------------------^
       5

which is weird given we allow

# main.vy
import lib1

exports: lib1. __interface__

i can't reproduce this. can you provide the contents you have for lib1.vy?

[charles-cooper]

# main.vy
import ITest2

exports: ITest2

# ITest2.vyi
def foo() -> uint8:
    ...
@view
def foobar() -> uint8:
    ...

yields:

Error compiling: tests/custom/test4.vy
vyper.exceptions.StructureException: not a function or interface: `type(tests/custom/ITest2.vyi)`

  contract "tests/custom/test4.vy:4", line 4:9 
       3
  ---> 4 exports: ITest2
  ----------------^
       5

i can't reproduce this. when i run this i get the error:

Error compiling: tmp/main.vy
vyper.exceptions.StructureException: invalid export

  contract "tmp/main.vy:6", line 6:0 
       5
  ---> 6 exports: ITest2
  -------^
       7

  (hint: exports should look like <module>.<function | interface>)

[charles-cooper]

a bit oos for this PR, but we allow for implements: I where I is an empty .vyi file - which most likely is a bug in the user code

https://github.com/vyperlang/vyper/pull/4322

[cyberthirst]

you can call __default__ through __interface__

# main.vy
import lib2

@external
def bar():
    extcall lib2.__interface__(self).__default__()

# lib2.vy
@external
def __default__():
    pass

i think you wanna be able to export it but not call it

[cyberthirst]

exports of the following form are allowed:

# main.vy
import lib2

a: address

exports: lib2.__interface__(self.a).__default__

# lib2.vy
@external
def __default__():
    pass

[charles-cooper]

exports of the following form are allowed:

# main.vy
import lib2

a: address

exports: lib2.__interface__(self.a).__default__

# lib2.vy
@external
def __default__():
    pass

ac43bebccc5a88e7a9b31e9ca5c5cbdc46f0fc5a

[charles-cooper]

would it be too much to ask for implicit cast of mod to mod.__interface__? For either v: Mod in argument (convert to Interface to use like v.method(...)) or extcall Mod(v).method(...) .__interface__ is a little awkward to specify

yes but it's a bit hairy. it will feel ambiguous once we add deploy Mod(...) syntax

been thinking about this more and maybe it's feasible? since we already guard external calls with extcall or staticcall, you can kind of tell what type you get from the call AST context

x: Mod = deploy Mod(args...)
   ^^^          ^^^
   type: interface
                type: module ctor

extcall Mod(addr)
        ^^^
        type: interface

it will be kind of confusing to have Mod be a module or interface depending on context, though.

[charles-cooper]

another fun alternative that is slightly less verbose is:

extcall Mod.__at__(addr).foo()

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 32.50000% with 27 lines in your changes missing coverage. Please review.

Project coverage is 47.70%. Comparing base (b3ea663) to head (9bac423). Report is 10 commits behind head on master.

Files with missing lines	Patch %	Lines
vyper/semantics/analysis/module.py	10.00%	9 Missing :warning:
vyper/codegen/expr.py	20.00%	8 Missing :warning:
vyper/semantics/types/module.py	54.54%	5 Missing :warning:
vyper/compiler/output.py	0.00%	1 Missing and 1 partial :warning:
vyper/semantics/analysis/utils.py	0.00%	0 Missing and 1 partial :warning:
vyper/semantics/types/base.py	66.66%	1 Missing :warning:
vyper/semantics/types/function.py	0.00%	1 Missing :warning:

:exclamation: There is a different number of reports uploaded between BASE (b3ea663) and HEAD (9bac423). Click for more details.

HEAD has 137 uploads less than BASE

Flag	BASE (b3ea663)	HEAD (9bac423)
	138	1

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #4090       +/-   ##
===========================================
- Coverage   91.40%   47.70%   -43.71%     
===========================================
  Files         112      112               
  Lines       15927    16028      +101     
  Branches     2694     2699        +5     
===========================================
- Hits        14558     7646     -6912     
- Misses        935     7749     +6814     
- Partials      434      633      +199     

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---

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[cyberthirst]

# lib1.vy
def doo():
    pass

# main.vy
import lib1

i: public(lib1.__interface__)

@external
def boo():
    pass

exports: self.i

Error compiling: tests/custom/test.vy
AttributeError: 'NoneType' object has no attribute '_metadata'

During handling of the above exception, another exception occurred:

vyper.exceptions.CompilerPanic: unhandled exception 'NoneType' object has no attribute '_metadata'

  contract "tests/custom/test.vy:9", line 9:0 
       8
  ---> 9 exports: self.i
  -------^


This is an unhandled internal compiler error. Please create an issue on Github to notify the developers!
https://github.com/vyperlang/vyper/issues/new?template=bug.md