def visit_FuncDef(self, node):
# Skip if no loop counters exist
if self.loop_counter_size == 0:
return
# Create loop_counter declaration/initialization
constants = [c_ast.Constant("int", '0') for i in range(self.loop_counter_size)]
init_list = c_ast.InitList(constants)
identifier_type = c_ast.IdentifierType(["int"])
type_decl = c_ast.TypeDecl("loop_counter", [], identifier_type)
dim = c_ast.Constant("int", str(self.loop_counter_size))
array_decl = c_ast.ArrayDecl(type_decl, dim, [])
decl = c_ast.Decl("loop_counter", [], [], [], array_decl, init_list, None)
node.body.block_items.insert(0, decl)
# Label for return values to goto
start_label = c_ast.Label("print_loop_counter", c_ast.EmptyStatement())
# Start and end labels used for inserting preprocessor commands for #if DEBUG_EN
end_label = c_ast.Label("print_loop_counter_end", c_ast.EmptyStatement())
# Write to file
if self.write_to_file:
stmt = c_ast.ID("write_array(loop_counter, %d)\n" % (self.loop_counter_size))
compound = c_ast.Compound([start_label, stmt, end_label])
# Print to stdout
else:
# Add printf to the end of function
# Start of printing
stmt_start = c_ast.ID("printf(\"loop counter = (\")")
# For loop
# int i;
identifier_type = c_ast.IdentifierType(["int"])
type_decl = c_ast.TypeDecl("i", [], identifier_type)
for_decl = c_ast.Decl("i", [], [], [], type_decl, [], None)
# i = 0
init = c_ast.Assignment("=", c_ast.ID("i"), c_ast.Constant("int", '0'))
# i < self.loop_counter_size
cond = c_ast.BinaryOp("<", c_ast.ID("i"), c_ast.Constant("int", str(self.loop_counter_size)))
# i++
next_stmt = c_ast.UnaryOp("p++", c_ast.ID("i"))
# printf in for
stmt = c_ast.ID("printf(\"%d, \", loop_counter[i])")
# Cosntruct for loop
stmt_for = c_ast.For(init, cond, next_stmt, stmt)
# End of printing
stmt_end = c_ast.ID("printf(\")\\n\")")
# Put it all together
body = c_ast.Compound([stmt_start, for_decl, stmt_for, stmt_end])
# Surround with labels
compound = c_ast.Compound([start_label, body, end_label])
node.body.block_items.append(compound)
def ConvertShortCircuitIf(if_stmt: c_ast.If, parent: c_ast.Node, id_gen: common.UniqueId):
cond = if_stmt.cond
if isinstance(cond, c_ast.UnaryOp) and cond.op == "!":
# for a not not just swap the branches
if_stmt.cond = cond.expr
if_stmt.iffalse, if_stmt.iftrue = if_stmt.iftrue, if_stmt.iffalse
ConvertShortCircuitIf(if_stmt, parent, id_gen)
return
if not isinstance(cond, c_ast.BinaryOp):
return
if cond.op != "&&" and cond.op != "||":
return
labelnext = id_gen.next("branch")
if cond.op == "&&":
if_stmt2 = c_ast.If(cond.left, c_ast.Goto(labelnext), if_stmt.iffalse)
else:
assert cond.op == "||"
if_stmt2 = c_ast.If(cond.left, if_stmt.iftrue, c_ast.Goto(labelnext))
if_stmt.cond = cond.right
stmts = common.GetStatementList(parent)
# this is easy to fix but basically guaranteed after running IfTransform
assert stmts, parent
pos = stmts.index(if_stmt)
stmts[pos:pos + 1] = [if_stmt2, c_ast.Label(labelnext, c_ast.EmptyStatement()), if_stmt]
ConvertShortCircuitIf(if_stmt2, parent, id_gen)
ConvertShortCircuitIf(if_stmt, parent, id_gen)
def ConvertWhileLoop(ast, id_gen: common.UniqueId):
def IsWhileLoop(node, _):
return isinstance(node, (c_ast.DoWhile, c_ast.While))
candidates = common.FindMatchingNodesPostOrder(ast, ast, IsWhileLoop)
for node, parent in candidates:
loop_label = id_gen.next("while")
test_label = loop_label + "_cond"
exit_label = loop_label + "_exit"
conditional = c_ast.If(node.cond, c_ast.Goto(loop_label), None)
block = [c_ast.Label(loop_label, c_ast.EmptyStatement()), node.stmt,
c_ast.Label(test_label, c_ast.EmptyStatement()), conditional,
c_ast.Label(exit_label, c_ast.EmptyStatement())]
if isinstance(node, c_ast.While):
block = [c_ast.Goto(test_label)] + block
common.ReplaceBreakAndContinue(node.stmt, node, test_label, exit_label)
common.ReplaceNode(parent, node, c_ast.Compound(block))
def visit_FuncDef(self, node):
label = c_ast.Label("predict_exec_time", c_ast.EmptyStatement())
decl = c_ast.Decl("exec_time", None, None, None,
c_ast.TypeDecl("exec_time", None, c_ast.IdentifierType(["float"])),
None, None)
assignment = c_ast.Assignment('=', c_ast.ID("exec_time"), c_ast.Constant("int", 0))
ret = c_ast.Return(c_ast.ID("exec_time"))
compound = c_ast.Compound([label, decl, assignment, ret])
node.body.block_items.append(compound)
def callback(expr: ca.Node, is_expr: bool) -> Optional[ca.Node]:
if indices[expr] in repl_cands_set:
return copy.deepcopy(repl_expr)
if expr == write and isinstance(write, ca.Assignment) and not keep_var:
if is_expr:
return write.lvalue
else:
return ca.EmptyStatement()
return None
def ConvertForLoop(ast, id_gen: common.UniqueId):
candidates = common.FindMatchingNodesPostOrder(
ast, ast, lambda n, _: isinstance(n, c_ast.For))
for node, parent in candidates:
loop_label = id_gen.next("for")
next_label = loop_label + "_next"
test_label = loop_label + "_cond"
exit_label = loop_label + "_exit"
goto = c_ast.Goto(loop_label)
conditional = c_ast.If(node.cond, goto, None) if node.cond else goto
block = ExtractForInitStatements(node.init) + [
c_ast.Goto(test_label),
c_ast.Label(loop_label, c_ast.EmptyStatement()), node.stmt,
c_ast.Label(next_label, c_ast.EmptyStatement()),
node.next if node.next else c_ast.EmptyStatement(),
c_ast.Label(test_label, c_ast.EmptyStatement()), conditional,
c_ast.Label(exit_label, c_ast.EmptyStatement())
]
common.ReplaceBreakAndContinue(node.stmt, node, next_label, exit_label)
common.ReplaceNode(parent, node, c_ast.Compound(block))
def ConvertToGotos(if_stmt: c_ast.If, parent, id_gen: common.UniqueId):
if (isinstance(if_stmt.iftrue, c_ast.Goto) and
isinstance(if_stmt.iffalse, c_ast.Goto) and
not isinstance(if_stmt.cond, c_ast.ExprList)):
return
label = id_gen.next("if")
labeltrue = label + "_true"
labelfalse = label + "_false"
labelend = label + "_end"
emptytrue = common.IsEmpty(if_stmt.iftrue) or isinstance(if_stmt.iftrue, c_ast.Goto)
emptyfalse = common.IsEmpty(if_stmt.iffalse) or isinstance(if_stmt.iffalse, c_ast.Goto)
seq: List[c_ast.Node] = []
# TODO: this should be done in EliminateExpressionLists(
if isinstance(if_stmt.cond, c_ast.ExprList):
exprs = if_stmt.cond.exprs
if_stmt.cond = exprs.pop(-1)
seq += exprs
seq.append(if_stmt)
if not emptytrue:
seq += [c_ast.Label(labeltrue, c_ast.EmptyStatement()), if_stmt.iftrue]
if not emptyfalse:
seq.append(c_ast.Goto(labelend))
if not emptyfalse:
seq += [c_ast.Label(labelfalse, c_ast.EmptyStatement()), if_stmt.iffalse]
seq.append(c_ast.Label(labelend, c_ast.EmptyStatement()))
if not isinstance(if_stmt.iftrue, c_ast.Goto):
if_stmt.iftrue = c_ast.Goto(labelend if emptytrue else labeltrue)
if not isinstance(if_stmt.iffalse, c_ast.Goto):
if_stmt.iffalse = c_ast.Goto(labelend if emptyfalse else labelfalse)
stmts = common.GetStatementList(parent)
if not stmts:
stmts = [if_stmt]
parent = common.ReplaceNode(parent, if_stmt, c_ast.Compound(stmts))
pos = stmts.index(if_stmt)
stmts[pos: pos + 1] = seq
def generic_visit(self, node):
#print(node.coord)
if (isinstance(node, c_ast.If)):
if (node.iftrue and not (isinstance(node.iftrue, c_ast.Compound))):
node.iftrue = c_ast.Compound([node.iftrue])
if (node.iffalse
and not (isinstance(node.iffalse, c_ast.Compound))):
node.iffalse = c_ast.Compound([node.iffalse])
elif (node.iffalse == None):
node.iffalse = c_ast.Compound([c_ast.EmptyStatement()])
elif (isinstance(node, c_ast.For)):
if (node.stmt and not (isinstance(node.stmt, c_ast.Compound))):
node.stmt = c_ast.Compound([node.stmt])
for c_name, c in node.children():
self.visit(c)
def _pt_trash(self, node):
if self._rounds == 0:
return c_ast.EmptyStatement()
filename = random.choice(random.choice(self._patterns))
with open(filename) as f:
ast = self._parser.parse(f.read())
code = None
for child in ast.ext:
if type(child) == c_ast.FuncDef and child.decl.name == 'pattern':
code = child.body
pattern = PatternVisitor(self._patterns, self._rounds - 1,
node)
pattern.visit(code)
self._pt_add_decls(pattern.decls)
elif type(child) == c_ast.Decl and type(
child.type) == c_ast.FuncDecl:
self._pt_add_decls([child])
assert code, 'Invalid pattern: {}'.format(filename)
return code
def generate_code(request, response):
for proto_file in request.proto_file:
output = []
ast = c_ast.FileAST([])
generator = c_generator.CGenerator()
ast.ext += [c_ast.EmptyStatement()]
# Parse request
for item, package in traverse(proto_file):
data = {
'package': proto_file.package or '<root>',
'filename': proto_file.name,
'name': item.name,
}
if isinstance(item, DescriptorProto):
data.update({
'type': 'Message',
'properties': [{'name': f.name, 'type': int(f.type)}
for f in item.field]
})
elif isinstance(item, EnumDescriptorProto):
data.update({
'type': 'Enum',
'values': [{'name': v.name, 'value': v.number}
for v in item.value]
})
output.append(data)
# Fill response
f = response.file.add()
f.name = proto_file.name + '.c'
f.content = generator.visit(ast)
def _pt_assign_choise(self, node):
return c_ast.EmptyStatement()
def do_nop(**kw):
return c_ast.EmptyStatement()
def __init__(self):
astnode = c_ast.EmptyStatement()
super().__init__(astnode)
def ast_to_cfg(self, ast: c_ast.Node) -> (c_ast.Node, c_ast.Node):
"""Recursively compute the CFG from a AST. Given a AST node (can be any
complex structure) the function will return the first and last nodes of the
CFG in a tuple and will modify `cfg` adding the corresponding nodes and
edges representing the final CFG.
Parameters
----------
ast : pycparser.c_ast.Node to be translated into a CFG
Returns
-------
A tuple with references to the first and last element of the CFG
"""
typ = type(ast)
entrynode = ControlFlowGraph.EntryNode()
exitnode = ControlFlowGraph.ExitNode()
self.add_node(entrynode)
self.add_node(exitnode)
# A c_ast.If in CFG is:
# cfg(body.true)
# / \
# if(cond) endif*
# \ /
# ----------------------
#
# returns (if(c), endif)
if typ == c_ast.If:
astif = c_ast.If(ast.cond, None, None, coord=ast.coord)
if_start = ControlFlowGraph.IfNode(astif)
self.add_node(if_start)
self.add_edge(entrynode, if_start)
true_branch_body_entry, true_branch_body_exit = self.ast_to_cfg(ast.iftrue)
asserttrue = ControlFlowGraph.AssertNode(ast.cond)
self.add_node(asserttrue)
self.add_edge(if_start, asserttrue)
self.add_edge(asserttrue, true_branch_body_entry)
self.join_adjacents_and_merge(asserttrue, removed_node=true_branch_body_entry)
self.join_adjacents_and_merge(exitnode, removed_node=true_branch_body_exit)
if ast.iffalse is not None:
false_branch_body_start, false_branch_body_last = self.ast_to_cfg(ast.iffalse)
if self.iffalse:
assertfalse = ControlFlowGraph.AssertNode(c_ast.UnaryOp("!", ast.cond))
self.add_node(assertfalse)
self.add_edge(if_start, assertfalse)
self.add_edge(assertfalse, false_branch_body_start)
else:
self.add_edge(if_start, false_branch_body_start)
self.join_adjacents_and_merge(assertfalse, removed_node=false_branch_body_start)
self.join_adjacents_and_merge(exitnode, removed_node=false_branch_body_last)
else:
if self.iffalse:
assertfalse = ControlFlowGraph.AssertNode(c_ast.UnaryOp("!", ast.cond))
self.add_node(assertfalse)
self.add_edge(if_start, assertfalse)
self.add_edge(assertfalse, exitnode)
else:
self.add_edge(if_start, exitnode)
# A c_ast.While in CFG is:
# cfg(body)
# / \
# while(c) endwhile* -->--+
# ^ \ / |
# | ---->---- |
# +----------------------------+
#
# returns (while(c), endwhile*)
elif typ == c_ast.While:
while_body_entry, while_body_exit = self.ast_to_cfg(ast.stmt)
astwhile = c_ast.While(ast.cond, None, coord=ast.coord)
whilenode = ControlFlowGraph.Node(astwhile)
self.add_node(whilenode)
self.add_edge(whilenode, exitnode)
self.add_edge(entrynode, whilenode)
asserttrue = ControlFlowGraph.AssertNode(ast.cond)
self.add_node(asserttrue)
self.add_edge(whilenode, asserttrue)
self.add_edge(asserttrue, while_body_entry)
self.join_adjacents_and_merge(asserttrue, removed_node=while_body_entry)
# In a while the last statement return to the while condition
if self.loop:
self.join_adjacents_and_merge(whilenode, removed_node=while_body_exit)
else:
self.join_adjacents_and_merge(exitnode, removed_node=while_body_exit)
# A c_ast.Compound in CFG is:
#
# cfg(block(1)) --> cfg(block(2)) --> ... --> cfg(block(n))
#
# return (cfg(block(1)).first, cfg(block(n)).last)
elif typ == c_ast.Compound:
items = ast.block_items
if items is not None:
first_node = items[0]
first_node_entry, prev_node_exit = self.ast_to_cfg(first_node)
self.join_adjacents_and_merge(entrynode, removed_node=first_node_entry)
if len(items) > 1:
for i in items[1:-1]:
i_node_entry, i_node_exit = self.ast_to_cfg(i)
self.join_adjacents_and_remove(prev_node_exit, i_node_entry)
prev_node_exit = i_node_exit
last_node = items[-1]
last_node_entry, last_node_exit = self.ast_to_cfg(last_node)
self.join_adjacents_and_remove(prev_node_exit, last_node_entry)
else:
last_node = first_node
last_node_exit = prev_node_exit
self.join_adjacents_and_merge(exitnode, removed_node=last_node_exit)
else:
noopnode = ControlFlowGraph.Node(c_ast.EmptyStatement(coord=ast.coord))
self.add_node(noopnode)
self.add_edge(entrynode, noopnode)
self.add_edge(noopnode, exitnode)
# A c_ast.Compound in CFG is:
#
# function.name --> cfg(function.body).first
#
# return (function.name, cfg(function.body).last)
elif typ == c_ast.FuncDef:
(first_body, last_body) = self.ast_to_cfg(ast.body)
astfuncdef = c_ast.FuncDef(ast.decl, ast.param_decls, None, coord=ast.coord)
funcdefnode = ControlFlowGraph.Node(astfuncdef)
self.add_node(funcdefnode)
self.add_edge(entrynode, funcdefnode)
self.add_edge(last_body, exitnode)
# we insert the FuncDef body CFG discarding its entry and exit nodes
self.join_adjacents_and_merge(funcdefnode, removed_node=first_body)
self.join_adjacents_and_merge(exitnode, removed_node=last_body)
else:
basicnode = ControlFlowGraph.Node(ast)
self.add_node(basicnode)
self.add_edge(entrynode, basicnode)
self.add_edge(basicnode, exitnode)
return entrynode, exitnode
def create_inline_function(self, function, caller):
"""
Create a modified version of the passed function that can be inlined.
"""
# Create a copy of the function
function_copy = copy.deepcopy(function)
# Find all declared variables and rename them to prevent aliasing with upper-level
self.decl_visitor = GetDeclVisitor()
self.decl_visitor.visit(function_copy.body)
for decl in self.decl_visitor.decls:
self.rename_visitor.new_visit(decl, decl + "_rename%d" % self.rename_counter, function_copy)
###################################
# Function Arguments
###################################
function_copy.body.block_items.insert(0, c_ast.ID("// End of arguments"))
args = []
ptr_args = []
# If it has arguments
if function_copy.decl.type.args:
# For each function argument and passed value
for (arg, init) in zip(function_copy.decl.type.args.params, caller.args.exprs):
# Pointers just get renamed, no re-declare
if isinstance(arg.type, c_ast.PtrDecl):
# Add pointer name to list
if isinstance(init, c_ast.UnaryOp):
ptr_args.append((self.get_Decl_name(arg), init.expr.name))
elif isinstance(init, c_ast.StructRef):
ptr_args.append((self.get_Decl_name(arg), self.cgenerator.visit(init)))
elif isinstance(init, c_ast.ID):
ptr_args.append((self.get_Decl_name(arg), init.name))
elif isinstance(init, c_ast.ArrayRef):
ptr_args.append((self.get_Decl_name(arg), init))
else:
raise Exception("Unsupported init type %s" % (type(init)))
# Arrays also get renamed, no re-declare
elif isinstance(arg.type, c_ast.ArrayDecl):
ptr_args.append((self.get_Decl_name(arg), init))
else:
# Assign passed value to argument declaration
arg.init = init
# Save list of argument name for renaming
arg_name = self.get_Decl_name(arg)
args.append(arg_name)
# Rename arguments to prevent aliasing with upper-level
self.rename_visitor.new_visit(arg_name, arg_name + "_rename%d" % self.rename_counter, function_copy.body)
self.set_Decl_name(arg, arg_name + "_rename%d" % self.rename_counter)
# Insert into start of function
function_copy.body.block_items.insert(0, arg)
# Rename pointers and arrays to the passed variable
for arg in ptr_args:
self.rename_visitor.new_visit(arg[0], arg[1], function_copy)
# Increment rename counter to ensure unique names
self.rename_counter += 1
# Add declaration for return value (if function is non-void)
if self.get_Function_type(function_copy) != "void":
# Copy the function type declaration
typedecl = copy.deepcopy(function.decl.type.type)
# Create a variable declaration using the function type
decl = c_ast.Decl(None, None, None, None, typedecl, None, None)
# Replace the variable name as return_value
self.set_Decl_name(decl, "return_value")
# Insert the return_value declaration at the start of the function
function_copy.body.block_items.insert(0, decl)
function_copy.body.block_items.insert(0, c_ast.ID("// Inline function: %s" % (function_copy.decl.name)))
###################################
# Return statements
###################################
# Replace returns with goto statement
return_label = "return%d" % (self.return_counter)
self.return_counter += 1
self.rtg_visitor.new_visit(return_label, function_copy)
# Create label for goto
function_copy.body.block_items.append(c_ast.Label(return_label, c_ast.EmptyStatement()))
return function_copy
# Generate AST
ast = parse_file(filename, use_cpp=True)
# Find all defined functions
v = GetFunctionsVisitor()
v.visit(ast)
functions = v.funcs
# Remove function calls from being embedded in conditionals
v = GetFuncDeclVisitor()
v.visit(ast)
v = RemoveIfFunctionVisitor(v.func_decls)
v.visit(ast)
# Inline functions
v = ExpandFunctionVisitor(top_func, functions)
v.visit(ast)
# Keep performing until no changes
while v.expanded:
v.expanded = False
v.visit(ast)
# Print out non-function top-levels
for c_name, c in ast.children():
if not isinstance(c, c_ast.FuncDef):
print_node(c)
print_node(c_ast.EmptyStatement())
# Print out top-level function
for function in functions:
if function.decl.name == top_func:
print_node(function)
