fix: call internal functions from constructor (#2496)

this commit allows the user to call internal functions from the     
`__init__` function. it does this by generating a call graph during the
annotation phase and then generating code for the functions called from
the init function for during deploy code generation

this also has a performance benefit (compiler time) because we can get
rid of the two-pass method for tracing frame size.

now that we have a call graph, this commit also introduces a topsort of
functions based on the call dependency tree. this ensures we can compile
functions that call functions that occur after them in the source code.

lastly, this commit also refactors vyper/codegen/module.py so that the
payable logic is cleaner, it uses properties instead of calculations
more, and cleans up properties on IRnode, FunctionSignature and Context.

examples/stock/company.vy

@@ -39,12 +39,6 @@ def __init__(_company: address, _total_shares: uint256, initial_price: uint256):
     # The company holds all the shares at first, but can sell them all.
     self.holdings[self.company] = _total_shares
 
-# Find out how much stock the company holds
-@view
-@internal
-def _stockAvailable() -> uint256:
-    return self.holdings[self.company]
-
 # Public function to allow external access to _stockAvailable
 @view
 @external
@@ -69,12 +63,6 @@ def buyStock():
     # Log the buy event.
     log Buy(msg.sender, buy_order)
 
-# Find out how much stock any address (that's owned by someone) has.
-@view
-@internal
-def _getHolding(_stockholder: address) -> uint256:
-    return self.holdings[_stockholder]
-
 # Public function to allow external access to _getHolding
 @view
 @external
@@ -135,12 +123,6 @@ def payBill(vendor: address, amount: uint256):
     # Log the payment event.
     log Pay(vendor, amount)
 
-# Return the amount in wei that a company has raised in stock offerings.
-@view
-@internal
-def _debt() -> uint256:
-    return (self.totalShares - self._stockAvailable()) * self.price
-
 # Public function to allow external access to _debt
 @view
 @external
@@ -154,3 +136,21 @@ def debt() -> uint256:
 @external
 def worth() -> uint256:
     return self.balance - self._debt()
+
+# Return the amount in wei that a company has raised in stock offerings.
+@view
+@internal
+def _debt() -> uint256:
+    return (self.totalShares - self._stockAvailable()) * self.price
+
+# Find out how much stock the company holds
+@view
+@internal
+def _stockAvailable() -> uint256:
+    return self.holdings[self.company]
+
+# Find out how much stock any address (that's owned by someone) has.
+@view
+@internal
+def _getHolding(_stockholder: address) -> uint256:
+    return self.holdings[_stockholder]

tests/conftest.py

@@ -114,11 +114,11 @@ def get_contract_module(source_code, *args, **kwargs):
 
 
 def get_compiler_gas_estimate(code, func):
-    ir_runtime = compiler.phases.CompilerData(code).ir_runtime
+    sigs = compiler.phases.CompilerData(code).function_signatures
     if func:
-        return compiler.utils.build_gas_estimates(ir_runtime)[func] + 22000
+        return compiler.utils.build_gas_estimates(sigs)[func] + 22000
     else:
-        return sum(compiler.utils.build_gas_estimates(ir_runtime).values()) + 22000
+        return sum(compiler.utils.build_gas_estimates(sigs).values()) + 22000
 
 
 def check_gas_on_chain(w3, tester, code, func=None, res=None):

tests/parser/features/test_immutable.py

@@ -212,3 +212,30 @@ def get_idx_two() -> int128:
     c = get_contract(code, *values)
     assert c.get_my_list() == expected_values
     assert c.get_idx_two() == expected_values[2][2][2]
+
+
+@pytest.mark.parametrize("n", range(5))
+def test_internal_function_with_immutables(get_contract, n):
+    code = """
+@internal
+def foo() -> uint256:
+    self.counter += 1
+    return self.counter
+
+counter: uint256
+VALUE: immutable(uint256)
+
+@external
+def __init__(x: uint256):
+    self.counter = x
+    self.foo()
+    VALUE = self.foo()
+    self.foo()
+
+@external
+def get_immutable() -> uint256:
+    return VALUE
+    """
+
+    c = get_contract(code, n)
+    assert c.get_immutable() == n + 2

tests/parser/features/test_init.py

@@ -21,3 +21,34 @@ def __init__(a: uint256):
     assert "CALLDATALOAD" in opcodes
     assert "CALLDATACOPY" not in opcodes[:ir_return_idx]
     assert "CALLDATALOAD" not in opcodes[:ir_return_idx]
+
+
+def test_init_calls_internal(get_contract, assert_compile_failed, assert_tx_failed):
+    code = """
+foo: public(uint8)
+@internal
+def bar(x: uint256) -> uint8:
+    return convert(x, uint8) * 7
+@external
+def __init__(a: uint256):
+    self.foo = self.bar(a)
+
+@external
+def baz() -> uint8:
+    return self.bar(convert(self.foo, uint256))
+    """
+    n = 5
+    c = get_contract(code, n)
+    assert c.foo() == n * 7
+    assert c.baz() == 245  # 5*7*7
+
+    n = 6
+    c = get_contract(code, n)
+    assert c.foo() == n * 7
+    assert_tx_failed(lambda: c.baz())
+
+    n = 255
+    assert_compile_failed(lambda: get_contract(code, n))
+
+    n = 256
+    assert_compile_failed(lambda: get_contract(code, n))

vyper/ast/signatures/__init__.py

@@ -1 +1 @@
-from .function_signature import FunctionSignature, VariableRecord
+from .function_signature import FrameInfo, FunctionSignature, VariableRecord

vyper/ast/signatures/function_signature.py

@@ -7,7 +7,7 @@
 from vyper.codegen.ir_node import Encoding
 from vyper.codegen.types import NodeType, parse_type
 from vyper.exceptions import StructureException
-from vyper.utils import cached_property, mkalphanum
+from vyper.utils import MemoryPositions, cached_property, mkalphanum
 
 # dict from function names to signatures
 FunctionSignatures = Dict[str, "FunctionSignature"]
@@ -66,6 +66,16 @@ class FunctionArg:
     ast_source: vy_ast.VyperNode
 
 
+@dataclass
+class FrameInfo:
+    frame_start: int
+    frame_size: int
+
+    @property
+    def mem_used(self):
+        return self.frame_size + MemoryPositions.RESERVED_MEMORY
+
+
 # Function signature object
 class FunctionSignature:
     def __init__(
@@ -84,19 +94,25 @@ def __init__(
         self.return_type = return_type
         self.mutability = mutability
         self.internal = internal
-        self.gas = None
+        self.gas_estimate = None
         self.nonreentrant_key = nonreentrant_key
         self.func_ast_code = func_ast_code
         self.is_from_json = is_from_json
 
         self.set_default_args()
 
+        # frame info is metadata that will be generated during codegen.
+        self.frame_info: Optional[FrameInfo] = None
+
     def __str__(self):
         input_name = "def " + self.name + "(" + ",".join([str(arg.typ) for arg in self.args]) + ")"
         if self.return_type:
             return input_name + " -> " + str(self.return_type) + ":"
         return input_name + ":"
 
+    def set_frame_info(self, frame_info):
+        self.frame_info = frame_info
+
     @cached_property
     def _ir_identifier(self) -> str:
         # we could do a bit better than this but it just needs to be unique
@@ -228,3 +244,7 @@ def is_default_func(self):
     @property
     def is_init_func(self):
         return self.name == "__init__"
+
+    @property
+    def is_regular_function(self):
+        return not self.is_default_func and not self.is_init_func

vyper/ast/signatures/interface.py

@@ -98,9 +98,9 @@ def mk_full_signature_from_json(abi):
 def _get_external_signatures(global_ctx, sig_formatter=lambda x: x):
     ret = []
 
-    for code in global_ctx._defs:
+    for func_ast in global_ctx._function_defs:
         sig = FunctionSignature.from_definition(
-            code,
+            func_ast,
             sigs=global_ctx._contracts,
             custom_structs=global_ctx._structs,
         )

vyper/codegen/context.py

@@ -5,7 +5,7 @@
 from vyper.ast import VyperNode
 from vyper.ast.signatures.function_signature import VariableRecord
 from vyper.codegen.types import NodeType
-from vyper.exceptions import CompilerPanic, FunctionDeclarationException
+from vyper.exceptions import CompilerPanic
 
 
 class Constancy(enum.Enum):
@@ -22,11 +22,7 @@ def __init__(
         vars_=None,
         sigs=None,
         forvars=None,
-        return_type=None,
         constancy=Constancy.Mutable,
-        is_internal=False,
-        is_payable=False,
-        # method_id="",
         sig=None,
     ):
         # In-memory variables, in the form (name, memory location, type)
@@ -41,9 +37,6 @@ def __init__(
         # Variables defined in for loops, e.g. for i in range(6): ...
         self.forvars = forvars or {}
 
-        # Return type of the function
-        self.return_type = return_type
-
         # Is the function constant?
         self.constancy = constancy
 
@@ -53,14 +46,9 @@ def __init__(
         # Whether we are currently parsing a range expression
         self.in_range_expr = False
 
-        # Is the function payable?
-        self.is_payable = is_payable
-
         # List of custom structs that have been defined.
         self.structs = global_ctx._structs
 
-        self.is_internal = is_internal
-
         # store global context
         self.global_ctx = global_ctx
 
@@ -73,23 +61,25 @@ def __init__(
         # Not intended to be accessed directly
         self.memory_allocator = memory_allocator
 
-        self._callee_frame_sizes = []
-
-        # Intermented values, used for internal IDs
+        # Incremented values, used for internal IDs
         self._internal_var_iter = 0
         self._scope_id_iter = 0
 
     def is_constant(self):
         return self.constancy is Constancy.Constant or self.in_assertion or self.in_range_expr
 
-    def register_callee(self, frame_size):
-        self._callee_frame_sizes.append(frame_size)
+    # convenience propreties
+    @property
+    def is_payable(self):
+        return self.sig.mutability == "payable"
 
     @property
-    def max_callee_frame_size(self):
-        if len(self._callee_frame_sizes) == 0:
-            return 0
-        return max(self._callee_frame_sizes)
+    def is_internal(self):
+        return self.sig.internal
+
+    @property
+    def return_type(self):
+        return self.sig.return_type
 
     #
     # Context Managers
@@ -248,23 +238,16 @@ def lookup_internal_function(self, method_name, args_ir, ast_source):
         the kwargs which need to be filled in by the compiler
         """
 
+        sig = self.sigs["self"].get(method_name, None)
+
         def _check(cond, s="Unreachable"):
             if not cond:
                 raise CompilerPanic(s)
 
-        sig = self.sigs["self"].get(method_name, None)
-        if sig is None:
-            raise FunctionDeclarationException(
-                "Function does not exist or has not been declared yet "
-                "(reminder: functions cannot call functions later in code "
-                "than themselves)",
-                ast_source,
-            )
-
-        _check(sig.internal)  # sanity check
-        # should have been caught during type checking, sanity check anyway
+        # these should have been caught during type checking; sanity check
+        _check(sig is not None)
+        _check(sig.internal)
         _check(len(sig.base_args) <= len(args_ir) <= len(sig.args))
-
         # more sanity check, that the types match
         # _check(all(l.typ == r.typ for (l, r) in zip(args_ir, sig.args))
 

vyper/codegen/function_definitions/__init__.py

@@ -1 +1 @@
-from .common import generate_ir_for_function, is_default_func, is_initializer  # noqa
+from .common import generate_ir_for_function  # noqa