// Copyright (c) Corporation for National Research Initiatives
package org.python.core;
import org.python.core.util.RelativeFile;
import org.python.expose.ExposedGet;
import org.python.expose.ExposedType;
/**
* A python traceback object.
*/
@ExposedType(name = "traceback", isBaseType = false)
public class PyTraceback extends PyObject {
public static final PyType TYPE = PyType.fromClass(PyTraceback.class);
@ExposedGet
public PyObject tb_next;
@ExposedGet
public PyFrame tb_frame;
@ExposedGet
public int tb_lineno;
public PyTraceback(PyTraceback next, PyFrame frame) {
super(TYPE);
tb_next = next;
tb_frame = frame;
tb_lineno = frame.f_code.getline(frame);
}
private String tracebackInfo() {
if (tb_frame == null || tb_frame.f_code == null) {
return String.format(" (no code object) at line %s\n", tb_lineno);
}
String line = null;
if (tb_frame.f_code.co_filename != null) {
line = getLine(tb_frame.f_code.co_filename, tb_lineno);
}
return String.format(" File \"%.500s\", line %d, in %.500s\n%s",
tb_frame.f_code.co_filename, tb_lineno, tb_frame.f_code.co_name,
line == null ? "" : " " + line);
}
/**
* Return the specified line of code from filename.
*
* @param filename a filename String
* @param lineno the line number
* @return a String line or null
*/
private String getLine(String filename, int lineno) {
RelativeFile file = new RelativeFile(filename);
try {
if (!file.isFile() || !file.canRead()) {
// XXX: We should run through sys.path until the filename is found
return null;
}
} catch (SecurityException e) {
return null; // If we don't have read access to the file, return null
}
PyFile pyFile;
try {
pyFile = new PyFile(tb_frame.f_code.co_filename, "U", -1);
} catch (PyException pye) {
return null;
}
String line = null;
int i = 0;
try {
for (i = 0; i < tb_lineno; i++) {
line = pyFile.readline().asString();
if (line.equals("")) {
break;
}
}
} catch (PyException pye) {
// Proceed to closing the file
}
try {
pyFile.close();
} catch (PyException pye) {
// Continue, we may have the line
}
if (line != null && i == tb_lineno) {
i = 0;
while (i < line.length()) {
char c = line.charAt(i);
if (c != ' ' && c != '\t' && c != '\014') {
break;
}
i++;
}
line = line.substring(i);
if (!line.endsWith("\n")) {
line += "\n";
}
} else {
line = null;
}
return line;
}
public void dumpStack(StringBuilder buf) {
buf.append(tracebackInfo());
if (tb_next != null && tb_next != this) {
((PyTraceback)tb_next).dumpStack(buf);
} else if (tb_next == this) {
buf.append("circularity detected!"+this+tb_next);
}
}
public String dumpStack() {
StringBuilder buf = new StringBuilder();
buf.append("Traceback (most recent call last):\n");
dumpStack(buf);
return buf.toString();
}
}