// Copyright (c) Corporation for National Research Initiatives
package org.python.core;
/**
* A python frame object.
*/
final public class PyFrame extends PyObject {
public PyFrame f_back;
public PyTableCode f_code;
public PyObject f_locals;
public PyObject f_globals;
public int f_lineno;
public PyObject f_builtins;
public PyObject[] f_fastlocals;
public PyCell[] f_env; // nested scopes: cell + free env
public int f_ncells;
public int f_nfreevars;
public int f_lasti;
public Object[] f_savedlocals;
// an interface to functions suitable for tracing, e.g. via sys.settrace()
public TraceFunction tracefunc;
private static final String[] __members__ = { "f_back", "f_code", "f_locals", "f_globals", "f_lineno",
"f_builtins", "f_trace" };
public PyFrame(PyTableCode code, PyObject locals, PyObject globals, PyObject builtins) {
f_code = code;
f_locals = locals;
f_globals = globals;
f_builtins = builtins;
// This needs work to be efficient with multiple interpreter states
if (locals == null && code != null) {
// ! f_fastlocals needed for arg passing too
if ((code.co_flags & PyTableCode.CO_OPTIMIZED) != 0 || code.nargs > 0) {
if (code.co_nlocals > 0) {
// internal: may change
f_fastlocals = new PyObject[code.co_nlocals - code.jy_npurecell];
}
} else
f_locals = new PyStringMap();
}
if (code != null) { // reserve space for env
int env_sz = 0;
if (code.co_freevars != null)
env_sz += (f_nfreevars = code.co_freevars.length);
if (code.co_cellvars != null)
env_sz += (f_ncells = code.co_cellvars.length);
if (env_sz > 0)
f_env = new PyCell[env_sz];
}
}
public PyFrame(PyTableCode code, PyObject globals) {
this(code, null, globals, null);
}
public String toString() {
if (f_code == null) {
return "<frame (unknown code) at line " + f_lineno + ">";
} else {
return "<frame in \"" + f_code.co_name + "\" at line " + f_lineno + ">";
}
}
public PyObject __dir__() {
PyString members[] = new PyString[__members__.length];
for (int i = 0; i < __members__.length; i++)
members[i] = new PyString(__members__[i]);
return new PyList(members);
}
private void throwReadonly(String name) {
for (int i = 0; i < __members__.length; i++)
if (__members__[i] == name)
throw Py.TypeError("readonly attribute");
throw Py.AttributeError(name);
}
public void __setattr__(String name, PyObject value) {
// In CPython, some of the frame's attributes are read/writeable
if (name == "f_trace")
tracefunc = new PythonTraceFunction(value);
// not yet implemented:
// f_exc_type
// f_exc_value
// f_exc_traceback
else
throwReadonly(name);
}
public void __delattr__(String name) {
if (name == "f_trace")
tracefunc = null;
// not yet implemented:
// f_exc_type
// f_exc_value
// f_exc_traceback
else
throwReadonly(name);
}
public PyObject __findattr__(String name) {
if (name == "f_locals")
return getf_locals();
else if (name == "f_trace") {
if (tracefunc instanceof PythonTraceFunction) {
return ((PythonTraceFunction) tracefunc).tracefunc;
}
return Py.None;
}
return super.__findattr__(name);
}
public PyObject getf_locals() {
if (f_locals == null)
f_locals = new PyStringMap();
if (f_code != null && (f_code.co_nlocals > 0 || f_nfreevars > 0)) {
int i;
if (f_fastlocals != null) {
for (i = 0; i < f_fastlocals.length; i++) {
PyObject o = f_fastlocals[i];
if (o != null)
f_locals.__setitem__(f_code.co_varnames[i], o);
}
if ((f_code.co_flags & PyTableCode.CO_OPTIMIZED) == 0)
f_fastlocals = null;
}
int j = 0;
for (i = 0; i < f_ncells; i++, j++) {
PyObject v = f_env[j].ob_ref;
if (v != null)
f_locals.__setitem__(f_code.co_cellvars[i], v);
}
for (i = 0; i < f_nfreevars; i++, j++) {
PyObject v = f_env[j].ob_ref;
if (v != null)
f_locals.__setitem__(f_code.co_freevars[i], v);
}
}
return f_locals;
}
public void setline(int line) {
f_lineno = line;
if (tracefunc != null)
tracefunc = tracefunc.traceLine(this, line);
}
public int getline() {
return f_lineno;
}
public PyObject getlocal(int index) {
if (f_fastlocals != null) {
PyObject ret = f_fastlocals[index];
if (ret != null)
return ret;
}
return getlocal(f_code.co_varnames[index]);
}
public PyObject getlocal(String index) {
// System.err.println("getlocal: "+index);
if (f_locals == null)
getf_locals();
PyObject ret = f_locals.__finditem__(index);
if (ret != null)
return ret;
throw Py.UnboundLocalError("local: '" + index + "'");
//return getglobal(index);
}
public PyObject getname(String index) {
if (f_locals == null)
getf_locals();
if (f_locals == f_globals)
return getglobal(index);
PyObject ret = f_locals.__finditem__(index);
if (ret != null)
return ret;
return getglobal(index);
}
public PyObject getglobal(String index) {
PyObject ret = f_globals.__finditem__(index);
if (ret != null) {
return ret;
}
// Set up f_builtins if not already set
if (f_builtins == null) {
f_builtins = Py.getSystemState().builtins;
}
ret = f_builtins.__finditem__(index);
if (ret != null)
return ret;
throw Py.NameError(index);
}
public void setlocal(int index, PyObject value) {
if (f_fastlocals != null)
f_fastlocals[index] = value;
else
setlocal(f_code.co_varnames[index], value);
}
public void setlocal(String index, PyObject value) {
if (f_locals == null)
getf_locals();
f_locals.__setitem__(index, value);
}
public void setglobal(String index, PyObject value) {
f_globals.__setitem__(index, value);
}
public void dellocal(int index) {
if (f_fastlocals != null) {
if (f_fastlocals[index] == null) {
throw Py.UnboundLocalError("local: '" + f_code.co_varnames[index] + "'");
}
f_fastlocals[index] = null;
} else
dellocal(f_code.co_varnames[index]);
}
public void dellocal(String index) {
if (f_locals == null)
getf_locals();
try {
f_locals.__delitem__(index);
} catch (PyException e) {
if (!Py.matchException(e, Py.KeyError))
throw e;
throw Py.UnboundLocalError("local: '" + index + "'");
}
}
public void delglobal(String index) {
f_globals.__delitem__(index);
}
// nested scopes helpers
public PyObject getclosure(int index) {
return f_env[index];
}
public PyObject getderef(int index) {
PyObject obj = f_env[index].ob_ref;
if (obj != null)
return obj;
String name;
if (index >= f_ncells)
name = f_code.co_freevars[index - f_ncells];
else
name = f_code.co_cellvars[index];
throw Py.UnboundLocalError("local: '" + name + "'");
}
public void setderef(int index, PyObject value) {
f_env[index].ob_ref = value;
}
public void to_cell(int parm_index, int env_index) {
f_env[env_index].ob_ref = f_fastlocals[parm_index];
}
}