scalpel.cfg.builder.CFGBuilder

class documentation

class CFGBuilder(ast.NodeVisitor): (source)

Constructor: CFGBuilder(separate)

Control flow graph builder.

A control flow graph builder is an ast.NodeVisitor that can walk through a program's AST and iteratively build the corresponding CFG.

Method	`__init__`	Undocumented
Method	`add_exit`	Add a new exit to a block.
Method	`add_statement`	Add a statement to a block.
Method	`build`	Build a CFG from an AST.
Method	`build_from_file`	Build a CFG from some Python source file.
Method	`build_from_src`	Build a CFG from some Python source code.
Method	`clean_cfg`	Remove the useless (empty) blocks from a CFG.
Method	`goto_new_block`	Undocumented
Method	`new_block`	Create a new block with a new id.
Method	`new_ClassCFG`	Create a new sub-CFG for a class definition and add it to the function CFGs of the CFG being built.
Method	`new_functionCFG`	Create a new sub-CFG for a function definition and add it to the function CFGs of the CFG being built.
Method	`new_loopguard`	Create a new block for a loop's guard if the current block is not empty. Links the current block to the new loop guard.
Method	`visit_AnnAssign`	Undocumented
Method	`visit_Assert`	Undocumented
Method	`visit_Assign`	Undocumented
Method	`visit_AsyncFor`	Undocumented
Method	`visit_AsyncFunctionDef`	Undocumented
Method	`visit_AsyncWith`	Undocumented
Method	`visit_AugAssign`	Undocumented
Method	`visit_Await`	Undocumented
Method	`visit_Break`	Undocumented
Method	`visit_Call`	Undocumented
Method	`visit_ClassDef`	Undocumented
Method	`visit_Continue`	Undocumented
Method	`visit_Delete`	Undocumented
Method	`visit_Expr`	Undocumented
Method	`visit_For`	Undocumented
Method	`visit_FunctionDef`	Undocumented
Method	`visit_Global`	Undocumented
Method	`visit_If`	Undocumented
Method	`visit_Import`	Undocumented
Method	`visit_ImportFrom`	Undocumented
Method	`visit_Nonlocal`	Undocumented
Method	`visit_Pass`	Undocumented
Method	`visit_Raise`	Undocumented
Method	`visit_Return`	Undocumented
Method	`visit_Try`	Undocumented
Method	`visit_While`	Undocumented
Method	`visit_With`	Undocumented
Method	`visit_Yield`	Undocumented
Class Variable	`__all__`	Undocumented
Instance Variable	`after_loop_block_stack`	Undocumented
Instance Variable	`cfg`	Undocumented
Instance Variable	`curr_loop_guard_stack`	Undocumented
Instance Variable	`current_block`	Undocumented
Instance Variable	`current_id`	Undocumented
Instance Variable	`enter_func_def`	Undocumented
Instance Variable	`separate_node_blocks`	Undocumented

def __init__(self, separate=False): (source) ¶

Undocumented

def add_exit(self, block, nextblock, exitcase=None): (source) ¶

Add a new exit to a block.

Parameters
block	A block to which an exit must be added.
nextblock	The block to which control jumps from the new exit.
exitcase	An AST node representing the 'case' (or condition) leading to the exit from the block in the program.

def add_statement(self, block, statement): (source) ¶

Add a statement to a block.

Parameters
block	A Block object to which a statement must be added.
statement	An AST node representing the statement that must be added to the current block.

def build(self, name, tree, asynchr=False, entry_id=0, flattened=False): (source) ¶

Build a CFG from an AST.

Parameters
name	The name of the CFG being built.
tree	The root of the AST from which the CFG must be built.
asynchr	Undocumented
entry_id	Value for the id of the entry block of the CFG.
flattened	if use k-v format for all CFGs while hiding its nested information. Key will be fully-qualified names.
async	Boolean indicating whether the CFG being built represents an asynchronous function or not. When the CFG of a Python program is being built, it is considered like a synchronous 'main' function.
Returns
The CFG produced from the AST.

def build_from_file(self, name, filepath, flattened=False): (source) ¶

Build a CFG from some Python source file.

Parameters
name	The name of the CFG being built.
filepath	The path to the file containing the Python source code to build the CFG from.
flattened	if use k-v format for all CFGs while hiding its nested information. Key will be fully-qualified names.
Returns
The CFG produced from the source file.

def build_from_src(self, name, src, flattened=False): (source) ¶

Build a CFG from some Python source code.

Parameters
name	The name of the CFG being built.
src	A string containing the source code to build the CFG from.
flattened	if use k-v format for all CFGs while hiding its nested information. Key will be fully-qualified names.
Returns
The CFG produced from the source code.

def clean_cfg(self, block, visited): (source) ¶

Remove the useless (empty) blocks from a CFG.

Parameters
block	The block from which to start traversing the CFG to clean it.
visited	A list of blocks that already have been visited by clean_cfg (recursive function).

def goto_new_block(self, node): (source) ¶

Undocumented

def new_block(self): (source) ¶

Create a new block with a new id.

Returns
A Block object with a new unique id.

def new_ClassCFG(self, node, asynchr=False): (source) ¶

Create a new sub-CFG for a class definition and add it to the function CFGs of the CFG being built.

Parameters
node	The AST node containing the function definition.
asynchr	Boolean indicating whether the function for which the CFG is being built is asynchronous or not.

def new_functionCFG(self, node, asynchr=False, enclosing_block_id=-1): (source) ¶

Create a new sub-CFG for a function definition and add it to the function CFGs of the CFG being built.

Parameters
node	The AST node containing the function definition.
asynchr	Undocumented
enclosing_block_id	Undocumented
async	Boolean indicating whether the function for which the CFG is being built is asynchronous or not.