fix[lang]: pure access analysis

[charles-cooper]

What I did

fix #3894, fix #3830

use analysis instead of pattern matching on syntax.
update code style for the pure decorator tests

How I did it

How to verify it

Commit message

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Description for the changelog

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.07%. Comparing base (4595938) to head (79d5edf).

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Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3895      +/-   ##
==========================================
- Coverage   86.34%   86.07%   -0.28%     
==========================================
  Files          92       92              
  Lines       14028    14036       +8     
  Branches     3083     3085       +2     
==========================================
- Hits        12113    12081      -32     
- Misses       1487     1517      +30     
- Partials      428      438      +10     

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[fubuloubu]

Is this a bug or an optimization?

[cyberthirst]

this isn't right?

src = """
first: public(uint256)
second: public(uint256)

@internal
@pure
def foo() -> uint256:
    return self.codesize

@deploy
def __init__():
    self.first = self.foo()


@external
def bar():
    self.second = self.foo() 
"""

c = b.loads(src)
print(c.first())
c.bar()
print(c.second())

outputs:

201
136

[charles-cooper]

this isn't right?

src = """
first: public(uint256)
second: public(uint256)

@internal
@pure
def foo() -> uint256:
    return self.codesize

@deploy
def __init__():
    self.first = self.foo()


@external
def bar():
    self.second = self.foo() 
"""

c = b.loads(src)
print(c.first())
c.bar()
print(c.second())

outputs:

201
136

hm yea we should probably ban codesize (it's not currently classified as a state variable)

[pcaversaccio]

This PR introduced a regression. Tracking here: #3902.