--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/DebugClients/Python/coverage/tracer.c Thu Apr 10 23:02:20 2014 +0200
@@ -0,0 +1,730 @@
+/* C-based Tracer for Coverage. */
+
+#include "Python.h"
+#include "compile.h" /* in 2.3, this wasn't part of Python.h */
+#include "eval.h" /* or this. */
+#include "structmember.h"
+#include "frameobject.h"
+
+/* Compile-time debugging helpers */
+#undef WHAT_LOG /* Define to log the WHAT params in the trace function. */
+#undef TRACE_LOG /* Define to log our bookkeeping. */
+#undef COLLECT_STATS /* Collect counters: stats are printed when tracer is stopped. */
+
+#if COLLECT_STATS
+#define STATS(x) x
+#else
+#define STATS(x)
+#endif
+
+/* Py 2.x and 3.x compatibility */
+
+#ifndef Py_TYPE
+#define Py_TYPE(o) (((PyObject*)(o))->ob_type)
+#endif
+
+#if PY_MAJOR_VERSION >= 3
+
+#define MyText_Type PyUnicode_Type
+#define MyText_Check(o) PyUnicode_Check(o)
+#define MyText_AS_BYTES(o) PyUnicode_AsASCIIString(o)
+#define MyText_AS_STRING(o) PyBytes_AS_STRING(o)
+#define MyInt_FromLong(l) PyLong_FromLong(l)
+
+#define MyType_HEAD_INIT PyVarObject_HEAD_INIT(NULL, 0)
+
+#else
+
+#define MyText_Type PyString_Type
+#define MyText_Check(o) PyString_Check(o)
+#define MyText_AS_BYTES(o) (Py_INCREF(o), o)
+#define MyText_AS_STRING(o) PyString_AS_STRING(o)
+#define MyInt_FromLong(l) PyInt_FromLong(l)
+
+#define MyType_HEAD_INIT PyObject_HEAD_INIT(NULL) 0,
+
+#endif /* Py3k */
+
+/* The values returned to indicate ok or error. */
+#define RET_OK 0
+#define RET_ERROR -1
+
+/* An entry on the data stack. For each call frame, we need to record the
+ dictionary to capture data, and the last line number executed in that
+ frame.
+*/
+typedef struct {
+ PyObject * file_data; /* PyMem_Malloc'ed, a borrowed ref. */
+ int last_line;
+} DataStackEntry;
+
+/* The CTracer type. */
+
+typedef struct {
+ PyObject_HEAD
+
+ /* Python objects manipulated directly by the Collector class. */
+ PyObject * should_trace;
+ PyObject * warn;
+ PyObject * data;
+ PyObject * should_trace_cache;
+ PyObject * arcs;
+
+ /* Has the tracer been started? */
+ int started;
+ /* Are we tracing arcs, or just lines? */
+ int tracing_arcs;
+
+ /*
+ The data stack is a stack of dictionaries. Each dictionary collects
+ data for a single source file. The data stack parallels the call stack:
+ each call pushes the new frame's file data onto the data stack, and each
+ return pops file data off.
+
+ The file data is a dictionary whose form depends on the tracing options.
+ If tracing arcs, the keys are line number pairs. If not tracing arcs,
+ the keys are line numbers. In both cases, the value is irrelevant
+ (None).
+ */
+ /* The index of the last-used entry in data_stack. */
+ int depth;
+ /* The file data at each level, or NULL if not recording. */
+ DataStackEntry * data_stack;
+ int data_stack_alloc; /* number of entries allocated at data_stack. */
+
+ /* The current file_data dictionary. Borrowed. */
+ PyObject * cur_file_data;
+
+ /* The line number of the last line recorded, for tracing arcs.
+ -1 means there was no previous line, as when entering a code object.
+ */
+ int last_line;
+
+ /* The parent frame for the last exception event, to fix missing returns. */
+ PyFrameObject * last_exc_back;
+ int last_exc_firstlineno;
+
+#if COLLECT_STATS
+ struct {
+ unsigned int calls;
+ unsigned int lines;
+ unsigned int returns;
+ unsigned int exceptions;
+ unsigned int others;
+ unsigned int new_files;
+ unsigned int missed_returns;
+ unsigned int stack_reallocs;
+ unsigned int errors;
+ } stats;
+#endif /* COLLECT_STATS */
+} CTracer;
+
+#define STACK_DELTA 100
+
+static int
+CTracer_init(CTracer *self, PyObject *args_unused, PyObject *kwds_unused)
+{
+#if COLLECT_STATS
+ self->stats.calls = 0;
+ self->stats.lines = 0;
+ self->stats.returns = 0;
+ self->stats.exceptions = 0;
+ self->stats.others = 0;
+ self->stats.new_files = 0;
+ self->stats.missed_returns = 0;
+ self->stats.stack_reallocs = 0;
+ self->stats.errors = 0;
+#endif /* COLLECT_STATS */
+
+ self->should_trace = NULL;
+ self->warn = NULL;
+ self->data = NULL;
+ self->should_trace_cache = NULL;
+ self->arcs = NULL;
+
+ self->started = 0;
+ self->tracing_arcs = 0;
+
+ self->depth = -1;
+ self->data_stack = PyMem_Malloc(STACK_DELTA*sizeof(DataStackEntry));
+ if (self->data_stack == NULL) {
+ STATS( self->stats.errors++; )
+ PyErr_NoMemory();
+ return RET_ERROR;
+ }
+ self->data_stack_alloc = STACK_DELTA;
+
+ self->cur_file_data = NULL;
+ self->last_line = -1;
+
+ self->last_exc_back = NULL;
+
+ return RET_OK;
+}
+
+static void
+CTracer_dealloc(CTracer *self)
+{
+ if (self->started) {
+ PyEval_SetTrace(NULL, NULL);
+ }
+
+ Py_XDECREF(self->should_trace);
+ Py_XDECREF(self->warn);
+ Py_XDECREF(self->data);
+ Py_XDECREF(self->should_trace_cache);
+
+ PyMem_Free(self->data_stack);
+
+ Py_TYPE(self)->tp_free((PyObject*)self);
+}
+
+#if TRACE_LOG
+static const char *
+indent(int n)
+{
+ static const char * spaces =
+ " "
+ " "
+ " "
+ " "
+ ;
+ return spaces + strlen(spaces) - n*2;
+}
+
+static int logging = 0;
+/* Set these constants to be a file substring and line number to start logging. */
+static const char * start_file = "tests/views";
+static int start_line = 27;
+
+static void
+showlog(int depth, int lineno, PyObject * filename, const char * msg)
+{
+ if (logging) {
+ printf("%s%3d ", indent(depth), depth);
+ if (lineno) {
+ printf("%4d", lineno);
+ }
+ else {
+ printf(" ");
+ }
+ if (filename) {
+ PyObject *ascii = MyText_AS_BYTES(filename);
+ printf(" %s", MyText_AS_STRING(ascii));
+ Py_DECREF(ascii);
+ }
+ if (msg) {
+ printf(" %s", msg);
+ }
+ printf("\n");
+ }
+}
+
+#define SHOWLOG(a,b,c,d) showlog(a,b,c,d)
+#else
+#define SHOWLOG(a,b,c,d)
+#endif /* TRACE_LOG */
+
+#if WHAT_LOG
+static const char * what_sym[] = {"CALL", "EXC ", "LINE", "RET "};
+#endif
+
+/* Record a pair of integers in self->cur_file_data. */
+static int
+CTracer_record_pair(CTracer *self, int l1, int l2)
+{
+ int ret = RET_OK;
+
+ PyObject * t = Py_BuildValue("(ii)", l1, l2);
+ if (t != NULL) {
+ if (PyDict_SetItem(self->cur_file_data, t, Py_None) < 0) {
+ STATS( self->stats.errors++; )
+ ret = RET_ERROR;
+ }
+ Py_DECREF(t);
+ }
+ else {
+ STATS( self->stats.errors++; )
+ ret = RET_ERROR;
+ }
+ return ret;
+}
+
+/*
+ * The Trace Function
+ */
+static int
+CTracer_trace(CTracer *self, PyFrameObject *frame, int what, PyObject *arg_unused)
+{
+ int ret = RET_OK;
+ PyObject * filename = NULL;
+ PyObject * tracename = NULL;
+ #if WHAT_LOG || TRACE_LOG
+ PyObject * ascii = NULL;
+ #endif
+
+ #if WHAT_LOG
+ if (what <= sizeof(what_sym)/sizeof(const char *)) {
+ ascii = MyText_AS_BYTES(frame->f_code->co_filename);
+ printf("trace: %s @ %s %d\n", what_sym[what], MyText_AS_STRING(ascii), frame->f_lineno);
+ Py_DECREF(ascii);
+ }
+ #endif
+
+ #if TRACE_LOG
+ ascii = MyText_AS_BYTES(frame->f_code->co_filename);
+ if (strstr(MyText_AS_STRING(ascii), start_file) && frame->f_lineno == start_line) {
+ logging = 1;
+ }
+ Py_DECREF(ascii);
+ #endif
+
+ /* See below for details on missing-return detection. */
+ if (self->last_exc_back) {
+ if (frame == self->last_exc_back) {
+ /* Looks like someone forgot to send a return event. We'll clear
+ the exception state and do the RETURN code here. Notice that the
+ frame we have in hand here is not the correct frame for the RETURN,
+ that frame is gone. Our handling for RETURN doesn't need the
+ actual frame, but we do log it, so that will look a little off if
+ you're looking at the detailed log.
+
+ If someday we need to examine the frame when doing RETURN, then
+ we'll need to keep more of the missed frame's state.
+ */
+ STATS( self->stats.missed_returns++; )
+ if (self->depth >= 0) {
+ if (self->tracing_arcs && self->cur_file_data) {
+ if (CTracer_record_pair(self, self->last_line, -self->last_exc_firstlineno) < 0) {
+ return RET_ERROR;
+ }
+ }
+ SHOWLOG(self->depth, frame->f_lineno, frame->f_code->co_filename, "missedreturn");
+ self->cur_file_data = self->data_stack[self->depth].file_data;
+ self->last_line = self->data_stack[self->depth].last_line;
+ self->depth--;
+ }
+ }
+ self->last_exc_back = NULL;
+ }
+
+
+ switch (what) {
+ case PyTrace_CALL: /* 0 */
+ STATS( self->stats.calls++; )
+ /* Grow the stack. */
+ self->depth++;
+ if (self->depth >= self->data_stack_alloc) {
+ STATS( self->stats.stack_reallocs++; )
+ /* We've outgrown our data_stack array: make it bigger. */
+ int bigger = self->data_stack_alloc + STACK_DELTA;
+ DataStackEntry * bigger_data_stack = PyMem_Realloc(self->data_stack, bigger * sizeof(DataStackEntry));
+ if (bigger_data_stack == NULL) {
+ STATS( self->stats.errors++; )
+ PyErr_NoMemory();
+ self->depth--;
+ return RET_ERROR;
+ }
+ self->data_stack = bigger_data_stack;
+ self->data_stack_alloc = bigger;
+ }
+
+ /* Push the current state on the stack. */
+ self->data_stack[self->depth].file_data = self->cur_file_data;
+ self->data_stack[self->depth].last_line = self->last_line;
+
+ /* Check if we should trace this line. */
+ filename = frame->f_code->co_filename;
+ tracename = PyDict_GetItem(self->should_trace_cache, filename);
+ if (tracename == NULL) {
+ STATS( self->stats.new_files++; )
+ /* We've never considered this file before. */
+ /* Ask should_trace about it. */
+ PyObject * args = Py_BuildValue("(OO)", filename, frame);
+ tracename = PyObject_Call(self->should_trace, args, NULL);
+ Py_DECREF(args);
+ if (tracename == NULL) {
+ /* An error occurred inside should_trace. */
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ if (PyDict_SetItem(self->should_trace_cache, filename, tracename) < 0) {
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ }
+ else {
+ Py_INCREF(tracename);
+ }
+
+ /* If tracename is a string, then we're supposed to trace. */
+ if (MyText_Check(tracename)) {
+ PyObject * file_data = PyDict_GetItem(self->data, tracename);
+ if (file_data == NULL) {
+ file_data = PyDict_New();
+ if (file_data == NULL) {
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ ret = PyDict_SetItem(self->data, tracename, file_data);
+ Py_DECREF(file_data);
+ if (ret < 0) {
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ }
+ self->cur_file_data = file_data;
+ /* Make the frame right in case settrace(gettrace()) happens. */
+ Py_INCREF(self);
+ frame->f_trace = (PyObject*)self;
+ SHOWLOG(self->depth, frame->f_lineno, filename, "traced");
+ }
+ else {
+ self->cur_file_data = NULL;
+ SHOWLOG(self->depth, frame->f_lineno, filename, "skipped");
+ }
+
+ Py_DECREF(tracename);
+
+ self->last_line = -1;
+ break;
+
+ case PyTrace_RETURN: /* 3 */
+ STATS( self->stats.returns++; )
+ /* A near-copy of this code is above in the missing-return handler. */
+ if (self->depth >= 0) {
+ if (self->tracing_arcs && self->cur_file_data) {
+ int first = frame->f_code->co_firstlineno;
+ if (CTracer_record_pair(self, self->last_line, -first) < 0) {
+ return RET_ERROR;
+ }
+ }
+
+ SHOWLOG(self->depth, frame->f_lineno, frame->f_code->co_filename, "return");
+ self->cur_file_data = self->data_stack[self->depth].file_data;
+ self->last_line = self->data_stack[self->depth].last_line;
+ self->depth--;
+ }
+ break;
+
+ case PyTrace_LINE: /* 2 */
+ STATS( self->stats.lines++; )
+ if (self->depth >= 0) {
+ SHOWLOG(self->depth, frame->f_lineno, frame->f_code->co_filename, "line");
+ if (self->cur_file_data) {
+ /* We're tracing in this frame: record something. */
+ if (self->tracing_arcs) {
+ /* Tracing arcs: key is (last_line,this_line). */
+ if (CTracer_record_pair(self, self->last_line, frame->f_lineno) < 0) {
+ return RET_ERROR;
+ }
+ }
+ else {
+ /* Tracing lines: key is simply this_line. */
+ PyObject * this_line = MyInt_FromLong(frame->f_lineno);
+ if (this_line == NULL) {
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ ret = PyDict_SetItem(self->cur_file_data, this_line, Py_None);
+ Py_DECREF(this_line);
+ if (ret < 0) {
+ STATS( self->stats.errors++; )
+ return RET_ERROR;
+ }
+ }
+ }
+ self->last_line = frame->f_lineno;
+ }
+ break;
+
+ case PyTrace_EXCEPTION:
+ /* Some code (Python 2.3, and pyexpat anywhere) fires an exception event
+ without a return event. To detect that, we'll keep a copy of the
+ parent frame for an exception event. If the next event is in that
+ frame, then we must have returned without a return event. We can
+ synthesize the missing event then.
+
+ Python itself fixed this problem in 2.4. Pyexpat still has the bug.
+ I've reported the problem with pyexpat as http://bugs.python.org/issue6359 .
+ If it gets fixed, this code should still work properly. Maybe some day
+ the bug will be fixed everywhere coverage.py is supported, and we can
+ remove this missing-return detection.
+
+ More about this fix: http://nedbatchelder.com/blog/200907/a_nasty_little_bug.html
+ */
+ STATS( self->stats.exceptions++; )
+ self->last_exc_back = frame->f_back;
+ self->last_exc_firstlineno = frame->f_code->co_firstlineno;
+ break;
+
+ default:
+ STATS( self->stats.others++; )
+ break;
+ }
+
+ return RET_OK;
+}
+
+/*
+ * Python has two ways to set the trace function: sys.settrace(fn), which
+ * takes a Python callable, and PyEval_SetTrace(func, obj), which takes
+ * a C function and a Python object. The way these work together is that
+ * sys.settrace(pyfn) calls PyEval_SetTrace(builtin_func, pyfn), using the
+ * Python callable as the object in PyEval_SetTrace. So sys.gettrace()
+ * simply returns the Python object used as the second argument to
+ * PyEval_SetTrace. So sys.gettrace() will return our self parameter, which
+ * means it must be callable to be used in sys.settrace().
+ *
+ * So we make our self callable, equivalent to invoking our trace function.
+ *
+ * To help with the process of replaying stored frames, this function has an
+ * optional keyword argument:
+ *
+ * def CTracer_call(frame, event, arg, lineno=0)
+ *
+ * If provided, the lineno argument is used as the line number, and the
+ * frame's f_lineno member is ignored.
+ */
+static PyObject *
+CTracer_call(CTracer *self, PyObject *args, PyObject *kwds)
+{
+ PyFrameObject *frame;
+ PyObject *what_str;
+ PyObject *arg;
+ int lineno = 0;
+ int what;
+ int orig_lineno;
+ PyObject *ret = NULL;
+
+ static char *what_names[] = {
+ "call", "exception", "line", "return",
+ "c_call", "c_exception", "c_return",
+ NULL
+ };
+
+ #if WHAT_LOG
+ printf("pytrace\n");
+ #endif
+
+ static char *kwlist[] = {"frame", "event", "arg", "lineno", NULL};
+
+ if (!PyArg_ParseTupleAndKeywords(args, kwds, "O!O!O|i:Tracer_call", kwlist,
+ &PyFrame_Type, &frame, &MyText_Type, &what_str, &arg, &lineno)) {
+ goto done;
+ }
+
+ /* In Python, the what argument is a string, we need to find an int
+ for the C function. */
+ for (what = 0; what_names[what]; what++) {
+ PyObject *ascii = MyText_AS_BYTES(what_str);
+ int should_break = !strcmp(MyText_AS_STRING(ascii), what_names[what]);
+ Py_DECREF(ascii);
+ if (should_break) {
+ break;
+ }
+ }
+
+ /* Save off the frame's lineno, and use the forced one, if provided. */
+ orig_lineno = frame->f_lineno;
+ if (lineno > 0) {
+ frame->f_lineno = lineno;
+ }
+
+ /* Invoke the C function, and return ourselves. */
+ if (CTracer_trace(self, frame, what, arg) == RET_OK) {
+ Py_INCREF(self);
+ ret = (PyObject *)self;
+ }
+
+ /* Clean up. */
+ frame->f_lineno = orig_lineno;
+
+done:
+ return ret;
+}
+
+static PyObject *
+CTracer_start(CTracer *self, PyObject *args_unused)
+{
+ PyEval_SetTrace((Py_tracefunc)CTracer_trace, (PyObject*)self);
+ self->started = 1;
+ self->tracing_arcs = self->arcs && PyObject_IsTrue(self->arcs);
+ self->last_line = -1;
+
+ /* start() returns a trace function usable with sys.settrace() */
+ Py_INCREF(self);
+ return (PyObject *)self;
+}
+
+static PyObject *
+CTracer_stop(CTracer *self, PyObject *args_unused)
+{
+ if (self->started) {
+ PyEval_SetTrace(NULL, NULL);
+ self->started = 0;
+ }
+
+ return Py_BuildValue("");
+}
+
+static PyObject *
+CTracer_get_stats(CTracer *self)
+{
+#if COLLECT_STATS
+ return Py_BuildValue(
+ "{sI,sI,sI,sI,sI,sI,sI,sI,si,sI}",
+ "calls", self->stats.calls,
+ "lines", self->stats.lines,
+ "returns", self->stats.returns,
+ "exceptions", self->stats.exceptions,
+ "others", self->stats.others,
+ "new_files", self->stats.new_files,
+ "missed_returns", self->stats.missed_returns,
+ "stack_reallocs", self->stats.stack_reallocs,
+ "stack_alloc", self->data_stack_alloc,
+ "errors", self->stats.errors
+ );
+#else
+ return Py_BuildValue("");
+#endif /* COLLECT_STATS */
+}
+
+static PyMemberDef
+CTracer_members[] = {
+ { "should_trace", T_OBJECT, offsetof(CTracer, should_trace), 0,
+ PyDoc_STR("Function indicating whether to trace a file.") },
+
+ { "warn", T_OBJECT, offsetof(CTracer, warn), 0,
+ PyDoc_STR("Function for issuing warnings.") },
+
+ { "data", T_OBJECT, offsetof(CTracer, data), 0,
+ PyDoc_STR("The raw dictionary of trace data.") },
+
+ { "should_trace_cache", T_OBJECT, offsetof(CTracer, should_trace_cache), 0,
+ PyDoc_STR("Dictionary caching should_trace results.") },
+
+ { "arcs", T_OBJECT, offsetof(CTracer, arcs), 0,
+ PyDoc_STR("Should we trace arcs, or just lines?") },
+
+ { NULL }
+};
+
+static PyMethodDef
+CTracer_methods[] = {
+ { "start", (PyCFunction) CTracer_start, METH_VARARGS,
+ PyDoc_STR("Start the tracer") },
+
+ { "stop", (PyCFunction) CTracer_stop, METH_VARARGS,
+ PyDoc_STR("Stop the tracer") },
+
+ { "get_stats", (PyCFunction) CTracer_get_stats, METH_VARARGS,
+ PyDoc_STR("Get statistics about the tracing") },
+
+ { NULL }
+};
+
+static PyTypeObject
+CTracerType = {
+ MyType_HEAD_INIT
+ "coverage.CTracer", /*tp_name*/
+ sizeof(CTracer), /*tp_basicsize*/
+ 0, /*tp_itemsize*/
+ (destructor)CTracer_dealloc, /*tp_dealloc*/
+ 0, /*tp_print*/
+ 0, /*tp_getattr*/
+ 0, /*tp_setattr*/
+ 0, /*tp_compare*/
+ 0, /*tp_repr*/
+ 0, /*tp_as_number*/
+ 0, /*tp_as_sequence*/
+ 0, /*tp_as_mapping*/
+ 0, /*tp_hash */
+ (ternaryfunc)CTracer_call, /*tp_call*/
+ 0, /*tp_str*/
+ 0, /*tp_getattro*/
+ 0, /*tp_setattro*/
+ 0, /*tp_as_buffer*/
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+ "CTracer objects", /* tp_doc */
+ 0, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ 0, /* tp_iter */
+ 0, /* tp_iternext */
+ CTracer_methods, /* tp_methods */
+ CTracer_members, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+ 0, /* tp_dictoffset */
+ (initproc)CTracer_init, /* tp_init */
+ 0, /* tp_alloc */
+ 0, /* tp_new */
+};
+
+/* Module definition */
+
+#define MODULE_DOC PyDoc_STR("Fast coverage tracer.")
+
+#if PY_MAJOR_VERSION >= 3
+
+static PyModuleDef
+moduledef = {
+ PyModuleDef_HEAD_INIT,
+ "coverage.tracer",
+ MODULE_DOC,
+ -1,
+ NULL, /* methods */
+ NULL,
+ NULL, /* traverse */
+ NULL, /* clear */
+ NULL
+};
+
+
+PyObject *
+PyInit_tracer(void)
+{
+ PyObject * mod = PyModule_Create(&moduledef);
+ if (mod == NULL) {
+ return NULL;
+ }
+
+ CTracerType.tp_new = PyType_GenericNew;
+ if (PyType_Ready(&CTracerType) < 0) {
+ Py_DECREF(mod);
+ return NULL;
+ }
+
+ Py_INCREF(&CTracerType);
+ PyModule_AddObject(mod, "CTracer", (PyObject *)&CTracerType);
+
+ return mod;
+}
+
+#else
+
+void
+inittracer(void)
+{
+ PyObject * mod;
+
+ mod = Py_InitModule3("coverage.tracer", NULL, MODULE_DOC);
+ if (mod == NULL) {
+ return;
+ }
+
+ CTracerType.tp_new = PyType_GenericNew;
+ if (PyType_Ready(&CTracerType) < 0) {
+ return;
+ }
+
+ Py_INCREF(&CTracerType);
+ PyModule_AddObject(mod, "CTracer", (PyObject *)&CTracerType);
+}
+
+#endif /* Py3k */
