Add support to top level variables

Fix #995

slither/analyses/data_dependency/data_dependency.py

@@ -14,6 +14,7 @@ from slither.core.declarations import (
     Structure,
 )
 from slither.core.declarations.solidity_import_placeholder import SolidityImportPlaceHolder
+from slither.core.variables.top_level_variable import TopLevelVariable
 from slither.core.variables.variable import Variable
 from slither.slithir.operations import Index, OperationWithLValue, InternalCall
 from slither.slithir.variables import (
@@ -410,6 +411,7 @@ def convert_variable_to_non_ssa(v):
             Function,
             Type,
             SolidityImportPlaceHolder,
+            TopLevelVariable,
         ),
     )
     return v

slither/core/scope/scope.py

@@ -6,6 +6,7 @@ from slither.core.declarations.custom_error_top_level import CustomErrorTopLevel
 from slither.core.declarations.enum_top_level import EnumTopLevel
 from slither.core.declarations.function_top_level import FunctionTopLevel
 from slither.core.declarations.structure_top_level import StructureTopLevel
+from slither.core.variables.top_level_variable import TopLevelVariable
 from slither.slithir.variables import Constant
 
 
@@ -36,6 +37,7 @@ class FileScope:
         self.imports: Set[Import] = set()
         self.pragmas: Set[Pragma] = set()
         self.structures: Dict[str, StructureTopLevel] = {}
+        self.variables: Dict[str, TopLevelVariable] = {}
 
     def add_accesible_scopes(self) -> bool:
         """
@@ -69,6 +71,9 @@ class FileScope:
             if not _dict_contain(new_scope.structures, self.structures):
                 self.structures.update(new_scope.structures)
                 learn_something = True
+            if not _dict_contain(new_scope.variables, self.variables):
+                self.variables.update(new_scope.variables)
+                learn_something = True
 
         return learn_something
 

slither/core/variables/top_level_variable.py

@@ -5,12 +5,14 @@ from slither.core.variables.variable import Variable
 
 if TYPE_CHECKING:
     from slither.core.cfg.node import Node
+    from slither.core.scope.scope import FileScope
 
 
 class TopLevelVariable(TopLevel, Variable):
-    def __init__(self):
+    def __init__(self, scope: "FileScope"):
         super().__init__()
         self._node_initialization: Optional["Node"] = None
+        self.file_scope = scope
 
     # endregion
     ###################################################################################

slither/slithir/utils/ssa.py

@@ -13,6 +13,7 @@ from slither.core.declarations.solidity_import_placeholder import SolidityImport
 from slither.core.solidity_types.type import Type
 from slither.core.variables.local_variable import LocalVariable
 from slither.core.variables.state_variable import StateVariable
+from slither.core.variables.top_level_variable import TopLevelVariable
 from slither.slithir.operations import (
     Assignment,
     Binary,
@@ -617,6 +618,7 @@ def get(
             Function,
             Type,
             SolidityImportPlaceHolder,
+            TopLevelVariable,
         ),
     )  # type for abi.decode(.., t)
     return variable

slither/slithir/utils/utils.py

@@ -2,6 +2,7 @@ from slither.core.variables.local_variable import LocalVariable
 from slither.core.variables.state_variable import StateVariable
 
 from slither.core.declarations.solidity_variables import SolidityVariable
+from slither.core.variables.top_level_variable import TopLevelVariable
 
 from slither.slithir.variables.temporary import TemporaryVariable
 from slither.slithir.variables.constant import Constant
@@ -15,6 +16,7 @@ def is_valid_rvalue(v):
         (
             StateVariable,
             LocalVariable,
+            TopLevelVariable,
             TemporaryVariable,
             Constant,
             SolidityVariable,

slither/solc_parsing/expressions/find_variable.py

@@ -19,6 +19,7 @@ from slither.core.solidity_types import (
     FunctionType,
     MappingType,
 )
+from slither.core.variables.top_level_variable import TopLevelVariable
 from slither.core.variables.variable import Variable
 from slither.exceptions import SlitherError
 from slither.solc_parsing.declarations.caller_context import CallerContextExpression
@@ -98,7 +99,9 @@ def _find_variable_in_function_parser(
 
 def _find_top_level(
     var_name: str, scope: "FileScope"
-) -> Tuple[Optional[Union[Enum, Structure, SolidityImportPlaceHolder, CustomError]], bool]:
+) -> Tuple[
+    Optional[Union[Enum, Structure, SolidityImportPlaceHolder, CustomError, TopLevelVariable]], bool
+]:
     """
     Return the top level variable use, and a boolean indicating if the variable returning was cretead
     If the variable was created, it has no source_mapping
@@ -126,6 +129,9 @@ def _find_top_level(
         if custom_error.solidity_signature == var_name:
             return custom_error, False
 
+    if var_name in scope.variables:
+        return scope.variables[var_name], False
+
     return None, False
 
 
@@ -210,6 +216,8 @@ def _find_variable_init(
 ) -> Tuple[List[Contract], List["Function"], FileScope,]:
     from slither.solc_parsing.declarations.contract import ContractSolc
     from slither.solc_parsing.declarations.function import FunctionSolc
+    from slither.solc_parsing.declarations.structure_top_level import StructureTopLevelSolc
+    from slither.solc_parsing.variables.top_level_variable import TopLevelVariableSolc
 
     direct_contracts: List[Contract]
     direct_functions_parser: List[Function]
@@ -244,6 +252,14 @@ def _find_variable_init(
         else:
             assert isinstance(underlying_function, FunctionContract)
             scope = underlying_function.contract.file_scope
+    elif isinstance(caller_context, StructureTopLevelSolc):
+        direct_contracts = []
+        direct_functions_parser = []
+        scope = caller_context.underlying_structure.file_scope
+    elif isinstance(caller_context, TopLevelVariableSolc):
+        direct_contracts = []
+        direct_functions_parser = []
+        scope = caller_context.underlying_variable.file_scope
     else:
         raise SlitherError(
             f"{type(caller_context)} ({caller_context} is not valid for find_variable"

slither/solc_parsing/slither_compilation_unit_solc.py

@@ -239,12 +239,13 @@ class SlitherCompilationUnitSolc:
                 self._parse_enum(top_level_data, filename)
 
             elif top_level_data[self.get_key()] == "VariableDeclaration":
-                var = TopLevelVariable()
-                var_parser = TopLevelVariableSolc(var, top_level_data)
+                var = TopLevelVariable(scope)
+                var_parser = TopLevelVariableSolc(var, top_level_data, self)
                 var.set_offset(top_level_data["src"], self._compilation_unit)
 
                 self._compilation_unit.variables_top_level.append(var)
                 self._variables_top_level_parser.append(var_parser)
+                scope.variables[var.name] = var
             elif top_level_data[self.get_key()] == "FunctionDefinition":
                 scope = self.compilation_unit.get_scope(filename)
                 func = FunctionTopLevel(self._compilation_unit, scope)
@@ -495,6 +496,7 @@ Please rename it, this name is reserved for Slither's internals"""
         for lib in libraries:
             self._analyze_struct_events(lib)
 
+        self._analyze_top_level_variables()
         self._analyze_top_level_structures()
 
         # Start with the contracts without inheritance
@@ -580,9 +582,9 @@ Please rename it, this name is reserved for Slither's internals"""
     def _analyze_top_level_variables(self):
         try:
             for var in self._variables_top_level_parser:
-                var.analyze(self)
+                var.analyze(var)
         except (VariableNotFound, KeyError) as e:
-            raise SlitherException(f"Missing struct {e} during top level structure analyze") from e
+            raise SlitherException(f"Missing {e} during variable analyze") from e
 
     def _analyze_params_top_level_function(self):
         for func_parser in self._functions_top_level_parser:

slither/solc_parsing/solidity_types/type_parsing.py

@@ -220,6 +220,7 @@ def parse_type(
     from slither.solc_parsing.declarations.custom_error import CustomErrorSolc
     from slither.solc_parsing.declarations.structure_top_level import StructureTopLevelSolc
     from slither.solc_parsing.slither_compilation_unit_solc import SlitherCompilationUnitSolc
+    from slither.solc_parsing.variables.top_level_variable import TopLevelVariableSolc
 
     sl: "SlitherCompilationUnit"
     # Note: for convenicence top level functions use the same parser than function in contract
@@ -245,9 +246,11 @@ def parse_type(
         all_enums += enums_direct_access
         contracts = sl.contracts
         functions = []
-    elif isinstance(caller_context, (StructureTopLevelSolc, CustomErrorSolc)):
+    elif isinstance(caller_context, (StructureTopLevelSolc, CustomErrorSolc, TopLevelVariableSolc)):
         if isinstance(caller_context, StructureTopLevelSolc):
             scope = caller_context.underlying_structure.file_scope
+        elif isinstance(caller_context, TopLevelVariableSolc):
+            scope = caller_context.underlying_variable.file_scope
         else:
             assert isinstance(caller_context, CustomErrorSolc)
             custom_error = caller_context.underlying_custom_error

slither/solc_parsing/variables/top_level_variable.py

@@ -1,12 +1,38 @@
-from typing import Dict
+from typing import Dict, TYPE_CHECKING
 
 from slither.core.variables.top_level_variable import TopLevelVariable
 from slither.solc_parsing.variables.variable_declaration import VariableDeclarationSolc
+from slither.solc_parsing.declarations.caller_context import CallerContextExpression
 
+if TYPE_CHECKING:
+    from slither.solc_parsing.slither_compilation_unit_solc import SlitherCompilationUnitSolc
+    from slither.core.compilation_unit import SlitherCompilationUnit
 
-class TopLevelVariableSolc(VariableDeclarationSolc):
-    def __init__(self, variable: TopLevelVariable, variable_data: Dict):
+
+class TopLevelVariableSolc(VariableDeclarationSolc, CallerContextExpression):
+    def __init__(
+        self,
+        variable: TopLevelVariable,
+        variable_data: Dict,
+        slither_parser: "SlitherCompilationUnitSolc",
+    ):
         super().__init__(variable, variable_data)
+        self._slither_parser = slither_parser
+
+    @property
+    def is_compact_ast(self) -> bool:
+        return self._slither_parser.is_compact_ast
+
+    @property
+    def compilation_unit(self) -> "SlitherCompilationUnit":
+        return self._slither_parser.compilation_unit
+
+    def get_key(self) -> str:
+        return self._slither_parser.get_key()
+
+    @property
+    def slither_parser(self) -> "SlitherCompilationUnitSolc":
+        return self._slither_parser
 
     @property
     def underlying_variable(self) -> TopLevelVariable: