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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
// Copyright (c) Corporation for National Research Initiatives
package org.python.core;
/**
* A Python frame object.
*/
public class PyFrame extends PyObject
{
public PyFrame f_back;
public PyBaseCode f_code;
public PyObject f_locals;
public PyObject f_globals;
public int f_lineno;
public PyObject f_builtins;
public PyObject[] f_fastlocals;
/** nested scopes: cell + free env. */
public PyCell[] f_env;
public int f_ncells;
public int f_nfreevars;
public int f_lasti;
public Object[] f_savedlocals;
private int env_j = 0;
private Object generatorInput = Py.None;
// with context exits - used by generated bytecode
public PyObject[] f_exits;
/** an interface to functions suitable for tracing, e.g. via
* sys.settrace(). */
public TraceFunction tracefunc;
private static final String NAME_ERROR_MSG = "name '%.200s' is not defined";
private static final String GLOBAL_NAME_ERROR_MSG = "global name '%.200s' is not defined";
private static final String UNBOUNDLOCAL_ERROR_MSG =
"local variable '%.200s' referenced before assignment";
private static final String[] __members__ = {"f_back", "f_code", "f_locals", "f_globals",
"f_lineno", "f_builtins", "f_trace"};
public PyFrame(PyBaseCode 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.isFlagSet(CodeFlag.CO_OPTIMIZED) || 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(PyBaseCode code, PyObject globals) {
this(code, null, globals, null);
}
/**
* Populate the frame with closure variables, but at most once.
*
* @param freevars a PyTuple value
*/
void setupEnv(PyTuple freevars) {
int ntotal = f_ncells + f_nfreevars;
// add space for the cellvars
for (; env_j < f_ncells; env_j++) {
f_env[env_j] = new PyCell();
}
// inherit the freevars
for (int i=0; env_j < ntotal; i++, env_j++) {
f_env[env_j] = (PyCell)freevars.pyget(i);
}
}
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);
}
void setGeneratorInput(Object value) {
generatorInput = value;
}
public Object getGeneratorInput() {
Object input = generatorInput;
generatorInput = Py.None;
return input;
}
public Object checkGeneratorInput() {
return generatorInput;
}
private void throwReadonly(String name) {
for (String member : __members__) {
if (member == 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);
} else {
throwReadonly(name);
}
// not yet implemented:
// f_exc_type
// f_exc_value
// f_exc_traceback
}
public void __delattr__(String name) {
if (name == "f_trace") {
tracefunc = null;
} else {
throwReadonly(name);
}
// not yet implemented:
// f_exc_type
// f_exc_value
// f_exc_traceback
}
public PyObject __findattr_ex__(String name) {
if (name == "f_locals") {
return getLocals();
} else if (name == "f_trace") {
if (tracefunc instanceof PythonTraceFunction) {
return ((PythonTraceFunction)tracefunc).tracefunc;
}
return Py.None;
}
return super.__findattr_ex__(name);
}
/**
* Return the locals dict. First merges the fast locals into
* f_locals, then returns the updated f_locals.
*
* @return a PyObject mapping of locals
*/
public PyObject getLocals() {
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.isFlagSet(CodeFlag.CO_OPTIMIZED)) {
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;
}
/**
* Return the current f_locals dict.
*
* @return a PyObject mapping of locals
*/
public PyObject getf_locals() {
// XXX: This could be deprecated, grab f_locals directly
// instead. only the compiler calls this
return f_locals;
}
//
// Track the current line number. Called by generated code.
//
// This is not to be confused with the CPython method
// frame_setlineno() which causes the interpreter to jump to
// the given line.
//
public void setline(int line) {
f_lineno = line;
if (tracefunc != null) {
tracefunc = tracefunc.traceLine(this, line);
}
}
public int getline() {
return f_code.getline(this);
}
public PyObject getlocal(int index) {
if (f_fastlocals != null) {
PyObject ret = f_fastlocals[index];
if (ret != null) {
return ret;
}
}
String name = f_code.co_varnames[index];
if (f_locals != null) {
PyObject ret = f_locals.__finditem__(name);
if (ret != null) {
return ret;
}
}
throw Py.UnboundLocalError(String.format(UNBOUNDLOCAL_ERROR_MSG, name));
}
public PyObject getname(String index) {
PyObject ret;
if (f_locals == null || f_locals == f_globals) {
ret = doGetglobal(index);
} else {
ret = f_locals.__finditem__(index);
if (ret != null) {
return ret;
}
ret = doGetglobal(index);
}
if (ret != null) {
return ret;
}
throw Py.NameError(String.format(NAME_ERROR_MSG, index));
}
public PyObject getglobal(String index) {
PyObject ret = doGetglobal(index);
if (ret != null) {
return ret;
}
throw Py.NameError(String.format(GLOBAL_NAME_ERROR_MSG, index));
}
private PyObject doGetglobal(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 = PySystemState.builtins;
}
return f_builtins.__finditem__(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) {
f_locals.__setitem__(index, value);
} else {
throw Py.SystemError(String.format("no locals found when storing '%s'", 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(String.format(UNBOUNDLOCAL_ERROR_MSG,
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) {
try {
f_locals.__delitem__(index);
} catch (PyException pye) {
if (pye.match(Py.KeyError)) {
throw Py.NameError(String.format(NAME_ERROR_MSG, index));
}
throw pye;
}
} else {
throw Py.SystemError(String.format("no locals when deleting '%s'", index));
}
}
public void delglobal(String index) {
try {
f_globals.__delitem__(index);
} catch (PyException pye) {
if (pye.match(Py.KeyError)) {
throw Py.NameError(String.format(GLOBAL_NAME_ERROR_MSG, index));
}
throw pye;
}
}
// 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(String.format(UNBOUNDLOCAL_ERROR_MSG, 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];
}
}