WIP of echidna guidance printer

Features:
        - Detect payable functions
        - Detect functions using assert/block.number/msg.sender/timestamp/msg.gas
        - Constant extraction (including binary type used)

slither/core/declarations/function.py

@@ -113,9 +113,11 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
         self._all_high_level_calls = None
         self._all_library_calls = None
         self._all_low_level_calls = None
+        self._all_solidity_calls = None
         self._all_state_variables_read = None
         self._all_solidity_variables_read = None
         self._all_state_variables_written = None
+        self._all_slithir_variables = None
         self._all_conditional_state_variables_read = None
         self._all_conditional_state_variables_read_with_loop = None
         self._all_conditional_solidity_variables_read = None
@@ -796,6 +798,14 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
                 lambda x: x.solidity_variables_read)
         return self._all_solidity_variables_read
 
+    def all_slithir_variables(self):
+        """ recursive version of slithir_variables
+        """
+        if self._all_slithir_variables is None:
+            self._all_slithir_variables = self._explore_functions(
+                lambda x: x.slithir_variable)
+        return self._all_slithir_variables
+
     def all_expressions(self):
         """ recursive version of variables_read
         """
@@ -846,6 +856,13 @@ class Function(ChildContract, ChildInheritance, SourceMapping):
             self._all_library_calls = self._explore_functions(lambda x: x.library_calls)
         return self._all_library_calls
 
+    def all_solidity_calls(self):
+        """ recursive version of solidity calls
+        """
+        if self._all_solidity_calls is None:
+            self._all_solidity_calls = self._explore_functions(lambda x: x.solidity_calls)
+        return self._all_solidity_calls
+
     @staticmethod
     def _explore_func_cond_read(func, include_loop):
         ret = [n.state_variables_read for n in func.nodes if n.is_conditional(include_loop)]

slither/core/variables/variable.py

@@ -78,6 +78,25 @@ class Variable(SourceMapping):
         assert isinstance(t, (Type, list)) or t is None
         self._type = t
 
+    @property
+    def function_name(self):
+        '''
+        Return the name of the variable as a function signature
+        :return:
+        '''
+        from slither.core.solidity_types import ArrayType, MappingType
+        variable_getter_args = ""
+        if type(self.type) is ArrayType:
+            length = 0
+            v = self
+            while type(v.type) is ArrayType:
+                length += 1
+                v = v.type
+            variable_getter_args = ','.join(["uint256"] * length)
+        elif type(self.type) is MappingType:
+            variable_getter_args = self.type.type_from
+
+        return f"{self.name}({variable_getter_args})"
 
     def __str__(self):
         return self._name

slither/printers/all_printers.py

@@ -13,4 +13,5 @@ from .summary.variable_order import VariableOrder
 from .summary.data_depenency import DataDependency
 from .summary.modifier_calls import Modifiers
 from .summary.require_calls import RequireOrAssert
-from .summary.constructor_calls import ConstructorPrinter
+from .summary.constructor_calls import ConstructorPrinter
+from .guidance.echidna import Echidna

slither/printers/guidance/echidna.py

@@ -0,0 +1,120 @@
+"""
+"""
+
+import json
+from collections import defaultdict
+from slither.printers.abstract_printer import AbstractPrinter
+from slither.core.declarations.solidity_variables import SolidityVariableComposed, SolidityFunction
+from slither.slithir.operations.binary import Binary, BinaryType
+
+from slither.slithir.variables import Constant
+
+
+def _extract_payable(slither):
+    ret = {}
+    for contract in slither.contracts:
+        payable_functions = [f.full_name for f in contract.functions_entry_points if f.payable]
+        if payable_functions:
+            ret[contract.name] = payable_functions
+    return ret
+
+def _extract_solidity_variable_usage(slither, sol_var):
+    ret = {}
+    for contract in slither.contracts:
+        functions_using_sol_var = []
+        for f in contract.functions_entry_points:
+            for v in f.all_solidity_variables_read():
+                if v == sol_var:
+                    functions_using_sol_var.append(f.full_name)
+                    break
+        if functions_using_sol_var:
+            ret[contract.name] = functions_using_sol_var
+    return ret
+
+def _extract_constant_functions(slither):
+    ret = {}
+    for contract in slither.contracts:
+        cst_functions = [f.full_name for f in contract.functions_entry_points if f.view or f.pure]
+        if cst_functions:
+            ret[contract.name] = cst_functions
+    return ret
+
+def _extract_assert(slither):
+    ret = {}
+    for contract in slither.contracts:
+        functions_using_assert = []
+        for f in contract.functions_entry_points:
+            for v in f.all_solidity_calls():
+                if v == SolidityFunction('assert(bool)'):
+                    functions_using_assert.append(f.full_name)
+                    break
+        if functions_using_assert:
+            ret[contract.name] = functions_using_assert
+    return ret
+
+
+def _extract_constants(slither):
+    ret_cst_used = defaultdict(dict)
+    ret_cst_used_in_binary = defaultdict(dict)
+    for contract in slither.contracts:
+        for function in contract.functions_entry_points:
+            all_cst_used = []
+            all_cst_used_in_binary = defaultdict(list)
+            for ir in function.all_slithir_operations():
+                if isinstance(ir, Binary):
+                    for r in ir.read:
+                        if isinstance(r, Constant):
+                            all_cst_used_in_binary[BinaryType.str(ir.type)].append(r.value)
+                for r in ir.read:
+                    if isinstance(r, Constant):
+                        all_cst_used.append(r.value)
+            if all_cst_used:
+                ret_cst_used[contract.name][function.full_name] = all_cst_used
+            if all_cst_used_in_binary:
+                ret_cst_used_in_binary[contract.name][function.full_name] = all_cst_used_in_binary
+    return (ret_cst_used, ret_cst_used_in_binary)
+
+
+
+
+class Echidna(AbstractPrinter):
+    ARGUMENT = 'echidna'
+    HELP = 'todo'
+
+    WIKI = 'https://github.com/trailofbits/slither/wiki/Printer-documentation#echidna'
+
+
+    def output(self, filename):
+        """
+            Output the inheritance relation
+
+            _filename is not used
+            Args:
+                _filename(string)
+        """
+
+        payable = _extract_payable(self.slither)
+        timestamp = _extract_solidity_variable_usage(self.slither,
+                                                     SolidityVariableComposed('block.timestamp'))
+        block_number = _extract_solidity_variable_usage(self.slither,
+                                                        SolidityVariableComposed('block.number'))
+        msg_sender = _extract_solidity_variable_usage(self.slither,
+                                                        SolidityVariableComposed('msg.sender'))
+        msg_gas = _extract_solidity_variable_usage(self.slither,
+                                                   SolidityVariableComposed('msg.gas'))
+        assert_usage = _extract_assert(self.slither)
+        cst_functions = _extract_constant_functions(self.slither)
+        (cst_used, cst_used_in_binary) = _extract_constants(self.slither)
+
+
+        d = {'payable': payable,
+             'timestamp': timestamp,
+             'block_number': block_number,
+             'msg_sender': msg_sender,
+             'msg_gas': msg_gas,
+             'assert': assert_usage,
+             'constant_functions': cst_functions,
+             'constants_used': cst_used,
+             'constants_used_in_binary': cst_used_in_binary}
+
+        print(json.dumps(d, indent=4))

slither/printers/summary/function_ids.py

@@ -4,7 +4,6 @@
 import collections
 from prettytable import PrettyTable
 
-from slither.core.solidity_types import ArrayType, MappingType
 from slither.printers.abstract_printer import AbstractPrinter
 from slither.utils.colors import blue, green, magenta
 from slither.utils.function import get_function_id
@@ -32,18 +31,8 @@ class FunctionIds(AbstractPrinter):
                     table.add_row([function.full_name, hex(get_function_id(function.full_name))])
             for variable in contract.state_variables:
                 if variable.visibility in ['public']:
-                    variable_getter_args = ""
-                    if type(variable.type) is ArrayType:
-                        length = 0
-                        v = variable
-                        while type(v.type) is ArrayType:
-                            length += 1
-                            v = v.type
-                        variable_getter_args = ','.join(["uint256"]*length)
-                    elif type(variable.type) is MappingType:
-                        variable_getter_args = variable.type.type_from
-
-                    table.add_row([f"{variable.name}({variable_getter_args})", hex(get_function_id(f"{variable.name}({variable_getter_args})"))])
+                    sig = variable.function_name
+                    table.add_row([sig, hex(get_function_id(sig))])
             txt += str(table) + '\n'
 
         self.info(txt)