From fe0a6faf9747d3619223ccef261affec3a5c83ac Mon Sep 17 00:00:00 2001
From: Olivier Stasse <olivier.stasse@gmail.com>
Date: Mon, 23 Jul 2012 17:25:03 +0200
Subject: [PATCH] Add test to detect statement in evaluation.
This commit detect when a statement is evaluated with PyRun_String run
with Py_eval_input. This seems to generate a Syntax Error. Thus if
an exception with Syntax Error is generated with Py_eval_input,
the python interpreter does a second pass with Py_single_input.
The string err is set appropriatly, out has to be checked.
---
src/interpreter.cc | 161 ++++++++++++++++++++++++++-------------------
1 file changed, 94 insertions(+), 67 deletions(-)
diff --git a/src/interpreter.cc b/src/interpreter.cc
index a0cd181..38ac726 100644
--- a/src/interpreter.cc
+++ b/src/interpreter.cc
@@ -43,6 +43,66 @@ namespace dynamicgraph {
using dynamicgraph::python::Interpreter;
using dynamicgraph::python::libpython;
+bool HandleErr(std::string & err,
+ PyObject * traceback_format_exception,
+ PyObject * globals_,
+ int PythonInputType)
+{
+ err="";
+ bool lres=false;
+
+ if (PyErr_Occurred()) {
+ std::cout << "v3.0 An exception was raised in the python interpreter." << std::endl;
+ PyObject *ptype, *pvalue, *ptraceback, *pyerr;
+ PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+ if (ptraceback == NULL) {
+ ptraceback = Py_None;
+ }
+ PyObject* args = PyTuple_New(3);
+ PyTuple_SET_ITEM(args, 0, ptype);
+ PyTuple_SET_ITEM(args, 1, pvalue);
+ PyTuple_SET_ITEM(args, 2, ptraceback);
+ pyerr = PyObject_CallObject(traceback_format_exception, args);
+ assert(PyList_Check(pyerr));
+ unsigned int size = PyList_GET_SIZE(pyerr);
+ std::string stringRes;
+ for (unsigned int i=0; i<size; i++) {
+ stringRes += std::string(PyString_AsString(PyList_GET_ITEM(pyerr, i)));
+ }
+ pyerr = PyString_FromString(stringRes.c_str());
+ err = PyString_AsString(pyerr);
+ std::cout << "err: " << err << std::endl;
+
+ // Here if there is a syntax error and
+ // and the interpreter input is set to Py_eval_input,
+ // it is maybe a statement instead of an expression.
+ // Therefore we indicate to re-evaluate the command.
+ if (PyErr_GivenExceptionMatches(ptype, PyExc_SyntaxError) &&
+ (PythonInputType==Py_eval_input))
+ {
+ std::cout << "Detected a syntax error " << std::endl;
+ lres=false;
+ }
+ else
+ lres=true;
+
+ PyErr_Clear();
+ } else {
+ std::cout << "no object generated but no error occured." << std::endl;
+ }
+ PyObject* stdout_obj = PyRun_String("stdout_catcher.fetch()",
+ Py_eval_input, globals_,
+ globals_);
+ std::string out("");
+
+ out = PyString_AsString(stdout_obj);
+ // Local display for the robot (in debug mode or for the logs)
+ if (out.length()!=0)
+ std::cout << out;
+ else std::cout << "No exception." << std::endl;
+ return lres;
+}
+
Interpreter::Interpreter()
{
// load python dynamic library
@@ -77,86 +137,45 @@ Interpreter::~Interpreter()
std::string Interpreter::python( const std::string& command )
{
- PyObject* result = PyRun_String(command.c_str(), Py_eval_input, globals_,
- globals_);
- if (!result) {
- PyErr_Clear();
- result = PyRun_String(command.c_str(), Py_single_input, globals_,
- globals_);
- }
- if (result == NULL) {
- if (PyErr_Occurred()) {
- PyObject *ptype, *pvalue, *ptraceback;
- PyErr_Fetch(&ptype, &pvalue, &ptraceback);
- if (ptraceback == NULL) {
- ptraceback = Py_None;
- }
- PyObject* args = PyTuple_New(3);
- PyTuple_SET_ITEM(args, 0, ptype);
- PyTuple_SET_ITEM(args, 1, pvalue);
- PyTuple_SET_ITEM(args, 2, ptraceback);
- result = PyObject_CallObject(traceback_format_exception_, args);
- assert(PyList_Check(result));
- unsigned int size = PyList_GET_SIZE(result);
- std::string stringRes;
- for (unsigned int i=0; i<size; i++) {
- stringRes += std::string(PyString_AsString(PyList_GET_ITEM(result, i)));
- }
- result = PyString_FromString(stringRes.c_str());
- PyErr_Clear();
- } else {
- std::cout << "Result is NULL but no error occurred." << std::endl;
- }
- } else {
- result = PyObject_Repr(result);
- }
- std::string value = "";
- // PyString_AsString will generate a segv if result is NULL.
- // This might be the case if PyObject_Repr fails.
- if (result!=NULL)
- value = PyString_AsString(result);
- return value;
+ std::string lerr(""),lout(""),lres("");
+ python(command,lres,lout,lerr);
+ return lres;
}
+
void Interpreter::python( const std::string& command, std::string& res,
std::string& out, std::string& err)
{
res = "";
out = "";
err = "";
+
PyObject* result = PyRun_String(command.c_str(), Py_eval_input, globals_,
globals_);
+ // Check if the result is null.
if (!result) {
- PyErr_Clear();
- result = PyRun_String(command.c_str(), Py_single_input, globals_,
- globals_);
- }
- if (result == NULL) {
- if (PyErr_Occurred()) {
- PyObject *ptype, *pvalue, *ptraceback, *pyerr;
- PyErr_Fetch(&ptype, &pvalue, &ptraceback);
- if (ptraceback == NULL) {
- ptraceback = Py_None;
- }
- PyObject* args = PyTuple_New(3);
- PyTuple_SET_ITEM(args, 0, ptype);
- PyTuple_SET_ITEM(args, 1, pvalue);
- PyTuple_SET_ITEM(args, 2, ptraceback);
- pyerr = PyObject_CallObject(traceback_format_exception_, args);
- assert(PyList_Check(pyerr));
- unsigned int size = PyList_GET_SIZE(pyerr);
- std::string stringRes;
- for (unsigned int i=0; i<size; i++) {
- stringRes += std::string(PyString_AsString(PyList_GET_ITEM(pyerr, i)));
+ // Test if this is a syntax error (due to the evaluation of an expression)
+ // else just output the problem.
+ if (!HandleErr(err,
+ traceback_format_exception_, globals_,
+ Py_eval_input))
+ {
+ // If this is a statement, re-parse the command.
+ result = PyRun_String(command.c_str(), Py_single_input, globals_, globals_);
+
+ // If there is still an error build the appropriate err string.
+ if (result == NULL)
+ HandleErr(err,
+ traceback_format_exception_, globals_,
+ Py_single_input);
+ else
+ // If there is no error, make sure that the previous error message is erased.
+ err="";
}
- pyerr = PyString_FromString(stringRes.c_str());
- err = PyString_AsString(pyerr);
- PyErr_Clear();
- } else {
- std::cout << "Result is NULL but no error occurred." << std::endl;
- }
+ else std::cout << "Do not try a second time." << std::endl;
}
+
PyObject* stdout_obj = PyRun_String("stdout_catcher.fetch()",
Py_eval_input, globals_,
globals_);
@@ -167,7 +186,15 @@ void Interpreter::python( const std::string& command, std::string& res,
// If python cannot build a string representation of result
// then results is equal to NULL. This will trigger a SEGV
if (result!=NULL)
- res = PyString_AsString(result);
+ {
+ std::cout << "For command :" << command << std::endl;
+ res = PyString_AsString(result);
+ std::cout << "Result is: " << res <<std::endl;
+ std::cout << "Out is: " << out <<std::endl;
+ std::cout << "Err is :" << err << std::endl;
+ }
+ else
+ std::cout << "Result is empty" << std::endl;
return;
}
--
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