Added Python (Thanks to Beholder) - it fails to build properly using my build system,
so there's a precompiled binary included, with a hack in Android.mk to make it work on NDK r4b
This commit is contained in:
pelya
656
project/jni/python/src/Objects/codeobject.c
Normal file
656
project/jni/python/src/Objects/codeobject.c
Normal file
@@ -0,0 +1,656 @@
|
||||
#include "Python.h"
|
||||
#include "code.h"
|
||||
#include "structmember.h"
|
||||
|
||||
#define NAME_CHARS \
|
||||
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz"
|
||||
|
||||
/* all_name_chars(s): true iff all chars in s are valid NAME_CHARS */
|
||||
|
||||
static int
|
||||
all_name_chars(unsigned char *s)
|
||||
{
|
||||
static char ok_name_char[256];
|
||||
static unsigned char *name_chars = (unsigned char *)NAME_CHARS;
|
||||
|
||||
if (ok_name_char[*name_chars] == 0) {
|
||||
unsigned char *p;
|
||||
for (p = name_chars; *p; p++)
|
||||
ok_name_char[*p] = 1;
|
||||
}
|
||||
while (*s) {
|
||||
if (ok_name_char[*s++] == 0)
|
||||
return 0;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void
|
||||
intern_strings(PyObject *tuple)
|
||||
{
|
||||
Py_ssize_t i;
|
||||
|
||||
for (i = PyTuple_GET_SIZE(tuple); --i >= 0; ) {
|
||||
PyObject *v = PyTuple_GET_ITEM(tuple, i);
|
||||
if (v == NULL || !PyString_CheckExact(v)) {
|
||||
Py_FatalError("non-string found in code slot");
|
||||
}
|
||||
PyString_InternInPlace(&PyTuple_GET_ITEM(tuple, i));
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
PyCodeObject *
|
||||
PyCode_New(int argcount, int nlocals, int stacksize, int flags,
|
||||
PyObject *code, PyObject *consts, PyObject *names,
|
||||
PyObject *varnames, PyObject *freevars, PyObject *cellvars,
|
||||
PyObject *filename, PyObject *name, int firstlineno,
|
||||
PyObject *lnotab)
|
||||
{
|
||||
PyCodeObject *co;
|
||||
Py_ssize_t i;
|
||||
/* Check argument types */
|
||||
if (argcount < 0 || nlocals < 0 ||
|
||||
code == NULL ||
|
||||
consts == NULL || !PyTuple_Check(consts) ||
|
||||
names == NULL || !PyTuple_Check(names) ||
|
||||
varnames == NULL || !PyTuple_Check(varnames) ||
|
||||
freevars == NULL || !PyTuple_Check(freevars) ||
|
||||
cellvars == NULL || !PyTuple_Check(cellvars) ||
|
||||
name == NULL || !PyString_Check(name) ||
|
||||
filename == NULL || !PyString_Check(filename) ||
|
||||
lnotab == NULL || !PyString_Check(lnotab) ||
|
||||
!PyObject_CheckReadBuffer(code)) {
|
||||
PyErr_BadInternalCall();
|
||||
return NULL;
|
||||
}
|
||||
intern_strings(names);
|
||||
intern_strings(varnames);
|
||||
intern_strings(freevars);
|
||||
intern_strings(cellvars);
|
||||
/* Intern selected string constants */
|
||||
for (i = PyTuple_Size(consts); --i >= 0; ) {
|
||||
PyObject *v = PyTuple_GetItem(consts, i);
|
||||
if (!PyString_Check(v))
|
||||
continue;
|
||||
if (!all_name_chars((unsigned char *)PyString_AS_STRING(v)))
|
||||
continue;
|
||||
PyString_InternInPlace(&PyTuple_GET_ITEM(consts, i));
|
||||
}
|
||||
co = PyObject_NEW(PyCodeObject, &PyCode_Type);
|
||||
if (co != NULL) {
|
||||
co->co_argcount = argcount;
|
||||
co->co_nlocals = nlocals;
|
||||
co->co_stacksize = stacksize;
|
||||
co->co_flags = flags;
|
||||
Py_INCREF(code);
|
||||
co->co_code = code;
|
||||
Py_INCREF(consts);
|
||||
co->co_consts = consts;
|
||||
Py_INCREF(names);
|
||||
co->co_names = names;
|
||||
Py_INCREF(varnames);
|
||||
co->co_varnames = varnames;
|
||||
Py_INCREF(freevars);
|
||||
co->co_freevars = freevars;
|
||||
Py_INCREF(cellvars);
|
||||
co->co_cellvars = cellvars;
|
||||
Py_INCREF(filename);
|
||||
co->co_filename = filename;
|
||||
Py_INCREF(name);
|
||||
co->co_name = name;
|
||||
co->co_firstlineno = firstlineno;
|
||||
Py_INCREF(lnotab);
|
||||
co->co_lnotab = lnotab;
|
||||
co->co_zombieframe = NULL;
|
||||
}
|
||||
return co;
|
||||
}
|
||||
|
||||
|
||||
#define OFF(x) offsetof(PyCodeObject, x)
|
||||
|
||||
static PyMemberDef code_memberlist[] = {
|
||||
{"co_argcount", T_INT, OFF(co_argcount), READONLY},
|
||||
{"co_nlocals", T_INT, OFF(co_nlocals), READONLY},
|
||||
{"co_stacksize",T_INT, OFF(co_stacksize), READONLY},
|
||||
{"co_flags", T_INT, OFF(co_flags), READONLY},
|
||||
{"co_code", T_OBJECT, OFF(co_code), READONLY},
|
||||
{"co_consts", T_OBJECT, OFF(co_consts), READONLY},
|
||||
{"co_names", T_OBJECT, OFF(co_names), READONLY},
|
||||
{"co_varnames", T_OBJECT, OFF(co_varnames), READONLY},
|
||||
{"co_freevars", T_OBJECT, OFF(co_freevars), READONLY},
|
||||
{"co_cellvars", T_OBJECT, OFF(co_cellvars), READONLY},
|
||||
{"co_filename", T_OBJECT, OFF(co_filename), READONLY},
|
||||
{"co_name", T_OBJECT, OFF(co_name), READONLY},
|
||||
{"co_firstlineno", T_INT, OFF(co_firstlineno), READONLY},
|
||||
{"co_lnotab", T_OBJECT, OFF(co_lnotab), READONLY},
|
||||
{NULL} /* Sentinel */
|
||||
};
|
||||
|
||||
/* Helper for code_new: return a shallow copy of a tuple that is
|
||||
guaranteed to contain exact strings, by converting string subclasses
|
||||
to exact strings and complaining if a non-string is found. */
|
||||
static PyObject*
|
||||
validate_and_copy_tuple(PyObject *tup)
|
||||
{
|
||||
PyObject *newtuple;
|
||||
PyObject *item;
|
||||
Py_ssize_t i, len;
|
||||
|
||||
len = PyTuple_GET_SIZE(tup);
|
||||
newtuple = PyTuple_New(len);
|
||||
if (newtuple == NULL)
|
||||
return NULL;
|
||||
|
||||
for (i = 0; i < len; i++) {
|
||||
item = PyTuple_GET_ITEM(tup, i);
|
||||
if (PyString_CheckExact(item)) {
|
||||
Py_INCREF(item);
|
||||
}
|
||||
else if (!PyString_Check(item)) {
|
||||
PyErr_Format(
|
||||
PyExc_TypeError,
|
||||
"name tuples must contain only "
|
||||
"strings, not '%.500s'",
|
||||
item->ob_type->tp_name);
|
||||
Py_DECREF(newtuple);
|
||||
return NULL;
|
||||
}
|
||||
else {
|
||||
item = PyString_FromStringAndSize(
|
||||
PyString_AS_STRING(item),
|
||||
PyString_GET_SIZE(item));
|
||||
if (item == NULL) {
|
||||
Py_DECREF(newtuple);
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
PyTuple_SET_ITEM(newtuple, i, item);
|
||||
}
|
||||
|
||||
return newtuple;
|
||||
}
|
||||
|
||||
PyDoc_STRVAR(code_doc,
|
||||
"code(argcount, nlocals, stacksize, flags, codestring, constants, names,\n\
|
||||
varnames, filename, name, firstlineno, lnotab[, freevars[, cellvars]])\n\
|
||||
\n\
|
||||
Create a code object. Not for the faint of heart.");
|
||||
|
||||
static PyObject *
|
||||
code_new(PyTypeObject *type, PyObject *args, PyObject *kw)
|
||||
{
|
||||
int argcount;
|
||||
int nlocals;
|
||||
int stacksize;
|
||||
int flags;
|
||||
PyObject *co = NULL;
|
||||
PyObject *code;
|
||||
PyObject *consts;
|
||||
PyObject *names, *ournames = NULL;
|
||||
PyObject *varnames, *ourvarnames = NULL;
|
||||
PyObject *freevars = NULL, *ourfreevars = NULL;
|
||||
PyObject *cellvars = NULL, *ourcellvars = NULL;
|
||||
PyObject *filename;
|
||||
PyObject *name;
|
||||
int firstlineno;
|
||||
PyObject *lnotab;
|
||||
|
||||
if (!PyArg_ParseTuple(args, "iiiiSO!O!O!SSiS|O!O!:code",
|
||||
&argcount, &nlocals, &stacksize, &flags,
|
||||
&code,
|
||||
&PyTuple_Type, &consts,
|
||||
&PyTuple_Type, &names,
|
||||
&PyTuple_Type, &varnames,
|
||||
&filename, &name,
|
||||
&firstlineno, &lnotab,
|
||||
&PyTuple_Type, &freevars,
|
||||
&PyTuple_Type, &cellvars))
|
||||
return NULL;
|
||||
|
||||
if (argcount < 0) {
|
||||
PyErr_SetString(
|
||||
PyExc_ValueError,
|
||||
"code: argcount must not be negative");
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
if (nlocals < 0) {
|
||||
PyErr_SetString(
|
||||
PyExc_ValueError,
|
||||
"code: nlocals must not be negative");
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
ournames = validate_and_copy_tuple(names);
|
||||
if (ournames == NULL)
|
||||
goto cleanup;
|
||||
ourvarnames = validate_and_copy_tuple(varnames);
|
||||
if (ourvarnames == NULL)
|
||||
goto cleanup;
|
||||
if (freevars)
|
||||
ourfreevars = validate_and_copy_tuple(freevars);
|
||||
else
|
||||
ourfreevars = PyTuple_New(0);
|
||||
if (ourfreevars == NULL)
|
||||
goto cleanup;
|
||||
if (cellvars)
|
||||
ourcellvars = validate_and_copy_tuple(cellvars);
|
||||
else
|
||||
ourcellvars = PyTuple_New(0);
|
||||
if (ourcellvars == NULL)
|
||||
goto cleanup;
|
||||
|
||||
co = (PyObject *)PyCode_New(argcount, nlocals, stacksize, flags,
|
||||
code, consts, ournames, ourvarnames,
|
||||
ourfreevars, ourcellvars, filename,
|
||||
name, firstlineno, lnotab);
|
||||
cleanup:
|
||||
Py_XDECREF(ournames);
|
||||
Py_XDECREF(ourvarnames);
|
||||
Py_XDECREF(ourfreevars);
|
||||
Py_XDECREF(ourcellvars);
|
||||
return co;
|
||||
}
|
||||
|
||||
static void
|
||||
code_dealloc(PyCodeObject *co)
|
||||
{
|
||||
Py_XDECREF(co->co_code);
|
||||
Py_XDECREF(co->co_consts);
|
||||
Py_XDECREF(co->co_names);
|
||||
Py_XDECREF(co->co_varnames);
|
||||
Py_XDECREF(co->co_freevars);
|
||||
Py_XDECREF(co->co_cellvars);
|
||||
Py_XDECREF(co->co_filename);
|
||||
Py_XDECREF(co->co_name);
|
||||
Py_XDECREF(co->co_lnotab);
|
||||
if (co->co_zombieframe != NULL)
|
||||
PyObject_GC_Del(co->co_zombieframe);
|
||||
PyObject_DEL(co);
|
||||
}
|
||||
|
||||
static PyObject *
|
||||
code_repr(PyCodeObject *co)
|
||||
{
|
||||
char buf[500];
|
||||
int lineno = -1;
|
||||
char *filename = "???";
|
||||
char *name = "???";
|
||||
|
||||
if (co->co_firstlineno != 0)
|
||||
lineno = co->co_firstlineno;
|
||||
if (co->co_filename && PyString_Check(co->co_filename))
|
||||
filename = PyString_AS_STRING(co->co_filename);
|
||||
if (co->co_name && PyString_Check(co->co_name))
|
||||
name = PyString_AS_STRING(co->co_name);
|
||||
PyOS_snprintf(buf, sizeof(buf),
|
||||
"<code object %.100s at %p, file \"%.300s\", line %d>",
|
||||
name, co, filename, lineno);
|
||||
return PyString_FromString(buf);
|
||||
}
|
||||
|
||||
static int
|
||||
code_compare(PyCodeObject *co, PyCodeObject *cp)
|
||||
{
|
||||
int cmp;
|
||||
cmp = PyObject_Compare(co->co_name, cp->co_name);
|
||||
if (cmp) return cmp;
|
||||
cmp = co->co_argcount - cp->co_argcount;
|
||||
if (cmp) goto normalize;
|
||||
cmp = co->co_nlocals - cp->co_nlocals;
|
||||
if (cmp) goto normalize;
|
||||
cmp = co->co_flags - cp->co_flags;
|
||||
if (cmp) goto normalize;
|
||||
cmp = co->co_firstlineno - cp->co_firstlineno;
|
||||
if (cmp) goto normalize;
|
||||
cmp = PyObject_Compare(co->co_code, cp->co_code);
|
||||
if (cmp) return cmp;
|
||||
cmp = PyObject_Compare(co->co_consts, cp->co_consts);
|
||||
if (cmp) return cmp;
|
||||
cmp = PyObject_Compare(co->co_names, cp->co_names);
|
||||
if (cmp) return cmp;
|
||||
cmp = PyObject_Compare(co->co_varnames, cp->co_varnames);
|
||||
if (cmp) return cmp;
|
||||
cmp = PyObject_Compare(co->co_freevars, cp->co_freevars);
|
||||
if (cmp) return cmp;
|
||||
cmp = PyObject_Compare(co->co_cellvars, cp->co_cellvars);
|
||||
return cmp;
|
||||
|
||||
normalize:
|
||||
if (cmp > 0)
|
||||
return 1;
|
||||
else if (cmp < 0)
|
||||
return -1;
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
|
||||
static PyObject *
|
||||
code_richcompare(PyObject *self, PyObject *other, int op)
|
||||
{
|
||||
PyCodeObject *co, *cp;
|
||||
int eq;
|
||||
PyObject *res;
|
||||
|
||||
if ((op != Py_EQ && op != Py_NE) ||
|
||||
!PyCode_Check(self) ||
|
||||
!PyCode_Check(other)) {
|
||||
|
||||
/* Py3K warning if types are not equal and comparison
|
||||
isn't == or != */
|
||||
if (PyErr_WarnPy3k("code inequality comparisons not supported "
|
||||
"in 3.x", 1) < 0) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
Py_INCREF(Py_NotImplemented);
|
||||
return Py_NotImplemented;
|
||||
}
|
||||
|
||||
co = (PyCodeObject *)self;
|
||||
cp = (PyCodeObject *)other;
|
||||
|
||||
eq = PyObject_RichCompareBool(co->co_name, cp->co_name, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = co->co_argcount == cp->co_argcount;
|
||||
if (!eq) goto unequal;
|
||||
eq = co->co_nlocals == cp->co_nlocals;
|
||||
if (!eq) goto unequal;
|
||||
eq = co->co_flags == cp->co_flags;
|
||||
if (!eq) goto unequal;
|
||||
eq = co->co_firstlineno == cp->co_firstlineno;
|
||||
if (!eq) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_code, cp->co_code, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_consts, cp->co_consts, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_names, cp->co_names, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_varnames, cp->co_varnames, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_freevars, cp->co_freevars, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
eq = PyObject_RichCompareBool(co->co_cellvars, cp->co_cellvars, Py_EQ);
|
||||
if (eq <= 0) goto unequal;
|
||||
|
||||
if (op == Py_EQ)
|
||||
res = Py_True;
|
||||
else
|
||||
res = Py_False;
|
||||
goto done;
|
||||
|
||||
unequal:
|
||||
if (eq < 0)
|
||||
return NULL;
|
||||
if (op == Py_NE)
|
||||
res = Py_True;
|
||||
else
|
||||
res = Py_False;
|
||||
|
||||
done:
|
||||
Py_INCREF(res);
|
||||
return res;
|
||||
}
|
||||
|
||||
static long
|
||||
code_hash(PyCodeObject *co)
|
||||
{
|
||||
long h, h0, h1, h2, h3, h4, h5, h6;
|
||||
h0 = PyObject_Hash(co->co_name);
|
||||
if (h0 == -1) return -1;
|
||||
h1 = PyObject_Hash(co->co_code);
|
||||
if (h1 == -1) return -1;
|
||||
h2 = PyObject_Hash(co->co_consts);
|
||||
if (h2 == -1) return -1;
|
||||
h3 = PyObject_Hash(co->co_names);
|
||||
if (h3 == -1) return -1;
|
||||
h4 = PyObject_Hash(co->co_varnames);
|
||||
if (h4 == -1) return -1;
|
||||
h5 = PyObject_Hash(co->co_freevars);
|
||||
if (h5 == -1) return -1;
|
||||
h6 = PyObject_Hash(co->co_cellvars);
|
||||
if (h6 == -1) return -1;
|
||||
h = h0 ^ h1 ^ h2 ^ h3 ^ h4 ^ h5 ^ h6 ^
|
||||
co->co_argcount ^ co->co_nlocals ^ co->co_flags;
|
||||
if (h == -1) h = -2;
|
||||
return h;
|
||||
}
|
||||
|
||||
/* XXX code objects need to participate in GC? */
|
||||
|
||||
PyTypeObject PyCode_Type = {
|
||||
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
||||
"code",
|
||||
sizeof(PyCodeObject),
|
||||
0,
|
||||
(destructor)code_dealloc, /* tp_dealloc */
|
||||
0, /* tp_print */
|
||||
0, /* tp_getattr */
|
||||
0, /* tp_setattr */
|
||||
(cmpfunc)code_compare, /* tp_compare */
|
||||
(reprfunc)code_repr, /* tp_repr */
|
||||
0, /* tp_as_number */
|
||||
0, /* tp_as_sequence */
|
||||
0, /* tp_as_mapping */
|
||||
(hashfunc)code_hash, /* tp_hash */
|
||||
0, /* tp_call */
|
||||
0, /* tp_str */
|
||||
PyObject_GenericGetAttr, /* tp_getattro */
|
||||
0, /* tp_setattro */
|
||||
0, /* tp_as_buffer */
|
||||
Py_TPFLAGS_DEFAULT, /* tp_flags */
|
||||
code_doc, /* tp_doc */
|
||||
0, /* tp_traverse */
|
||||
0, /* tp_clear */
|
||||
code_richcompare, /* tp_richcompare */
|
||||
0, /* tp_weaklistoffset */
|
||||
0, /* tp_iter */
|
||||
0, /* tp_iternext */
|
||||
0, /* tp_methods */
|
||||
code_memberlist, /* tp_members */
|
||||
0, /* tp_getset */
|
||||
0, /* tp_base */
|
||||
0, /* tp_dict */
|
||||
0, /* tp_descr_get */
|
||||
0, /* tp_descr_set */
|
||||
0, /* tp_dictoffset */
|
||||
0, /* tp_init */
|
||||
0, /* tp_alloc */
|
||||
code_new, /* tp_new */
|
||||
};
|
||||
|
||||
/* All about c_lnotab.
|
||||
|
||||
c_lnotab is an array of unsigned bytes disguised as a Python string. In -O
|
||||
mode, SET_LINENO opcodes aren't generated, and bytecode offsets are mapped
|
||||
to source code line #s (when needed for tracebacks) via c_lnotab instead.
|
||||
The array is conceptually a list of
|
||||
(bytecode offset increment, line number increment)
|
||||
pairs. The details are important and delicate, best illustrated by example:
|
||||
|
||||
byte code offset source code line number
|
||||
0 1
|
||||
6 2
|
||||
50 7
|
||||
350 307
|
||||
361 308
|
||||
|
||||
The first trick is that these numbers aren't stored, only the increments
|
||||
from one row to the next (this doesn't really work, but it's a start):
|
||||
|
||||
0, 1, 6, 1, 44, 5, 300, 300, 11, 1
|
||||
|
||||
The second trick is that an unsigned byte can't hold negative values, or
|
||||
values larger than 255, so (a) there's a deep assumption that byte code
|
||||
offsets and their corresponding line #s both increase monotonically, and (b)
|
||||
if at least one column jumps by more than 255 from one row to the next, more
|
||||
than one pair is written to the table. In case #b, there's no way to know
|
||||
from looking at the table later how many were written. That's the delicate
|
||||
part. A user of c_lnotab desiring to find the source line number
|
||||
corresponding to a bytecode address A should do something like this
|
||||
|
||||
lineno = addr = 0
|
||||
for addr_incr, line_incr in c_lnotab:
|
||||
addr += addr_incr
|
||||
if addr > A:
|
||||
return lineno
|
||||
lineno += line_incr
|
||||
|
||||
In order for this to work, when the addr field increments by more than 255,
|
||||
the line # increment in each pair generated must be 0 until the remaining addr
|
||||
increment is < 256. So, in the example above, com_set_lineno should not (as
|
||||
was actually done until 2.2) expand 300, 300 to 255, 255, 45, 45, but to
|
||||
255, 0, 45, 255, 0, 45.
|
||||
*/
|
||||
|
||||
int
|
||||
PyCode_Addr2Line(PyCodeObject *co, int addrq)
|
||||
{
|
||||
int size = PyString_Size(co->co_lnotab) / 2;
|
||||
unsigned char *p = (unsigned char*)PyString_AsString(co->co_lnotab);
|
||||
int line = co->co_firstlineno;
|
||||
int addr = 0;
|
||||
while (--size >= 0) {
|
||||
addr += *p++;
|
||||
if (addr > addrq)
|
||||
break;
|
||||
line += *p++;
|
||||
}
|
||||
return line;
|
||||
}
|
||||
|
||||
/*
|
||||
Check whether the current instruction is at the start of a line.
|
||||
|
||||
*/
|
||||
|
||||
/* The theory of SET_LINENO-less tracing.
|
||||
|
||||
In a nutshell, we use the co_lnotab field of the code object
|
||||
to tell when execution has moved onto a different line.
|
||||
|
||||
As mentioned above, the basic idea is so set things up so
|
||||
that
|
||||
|
||||
*instr_lb <= frame->f_lasti < *instr_ub
|
||||
|
||||
is true so long as execution does not change lines.
|
||||
|
||||
This is all fairly simple. Digging the information out of
|
||||
co_lnotab takes some work, but is conceptually clear.
|
||||
|
||||
Somewhat harder to explain is why we don't *always* call the
|
||||
line trace function when the above test fails.
|
||||
|
||||
Consider this code:
|
||||
|
||||
1: def f(a):
|
||||
2: if a:
|
||||
3: print 1
|
||||
4: else:
|
||||
5: print 2
|
||||
|
||||
which compiles to this:
|
||||
|
||||
2 0 LOAD_FAST 0 (a)
|
||||
3 JUMP_IF_FALSE 9 (to 15)
|
||||
6 POP_TOP
|
||||
|
||||
3 7 LOAD_CONST 1 (1)
|
||||
10 PRINT_ITEM
|
||||
11 PRINT_NEWLINE
|
||||
12 JUMP_FORWARD 6 (to 21)
|
||||
>> 15 POP_TOP
|
||||
|
||||
5 16 LOAD_CONST 2 (2)
|
||||
19 PRINT_ITEM
|
||||
20 PRINT_NEWLINE
|
||||
>> 21 LOAD_CONST 0 (None)
|
||||
24 RETURN_VALUE
|
||||
|
||||
If 'a' is false, execution will jump to instruction at offset
|
||||
15 and the co_lnotab will claim that execution has moved to
|
||||
line 3. This is at best misleading. In this case we could
|
||||
associate the POP_TOP with line 4, but that doesn't make
|
||||
sense in all cases (I think).
|
||||
|
||||
What we do is only call the line trace function if the co_lnotab
|
||||
indicates we have jumped to the *start* of a line, i.e. if the
|
||||
current instruction offset matches the offset given for the
|
||||
start of a line by the co_lnotab.
|
||||
|
||||
This also takes care of the situation where 'a' is true.
|
||||
Execution will jump from instruction offset 12 to offset 21.
|
||||
Then the co_lnotab would imply that execution has moved to line
|
||||
5, which is again misleading.
|
||||
|
||||
Why do we set f_lineno when tracing? Well, consider the code
|
||||
above when 'a' is true. If stepping through this with 'n' in
|
||||
pdb, you would stop at line 1 with a "call" type event, then
|
||||
line events on lines 2 and 3, then a "return" type event -- but
|
||||
you would be shown line 5 during this event. This is a change
|
||||
from the behaviour in 2.2 and before, and I've found it
|
||||
confusing in practice. By setting and using f_lineno when
|
||||
tracing, one can report a line number different from that
|
||||
suggested by f_lasti on this one occasion where it's desirable.
|
||||
*/
|
||||
|
||||
|
||||
int
|
||||
PyCode_CheckLineNumber(PyCodeObject* co, int lasti, PyAddrPair *bounds)
|
||||
{
|
||||
int size, addr, line;
|
||||
unsigned char* p;
|
||||
|
||||
p = (unsigned char*)PyString_AS_STRING(co->co_lnotab);
|
||||
size = PyString_GET_SIZE(co->co_lnotab) / 2;
|
||||
|
||||
addr = 0;
|
||||
line = co->co_firstlineno;
|
||||
assert(line > 0);
|
||||
|
||||
/* possible optimization: if f->f_lasti == instr_ub
|
||||
(likely to be a common case) then we already know
|
||||
instr_lb -- if we stored the matching value of p
|
||||
somwhere we could skip the first while loop. */
|
||||
|
||||
/* see comments in compile.c for the description of
|
||||
co_lnotab. A point to remember: increments to p
|
||||
should come in pairs -- although we don't care about
|
||||
the line increments here, treating them as byte
|
||||
increments gets confusing, to say the least. */
|
||||
|
||||
bounds->ap_lower = 0;
|
||||
while (size > 0) {
|
||||
if (addr + *p > lasti)
|
||||
break;
|
||||
addr += *p++;
|
||||
if (*p)
|
||||
bounds->ap_lower = addr;
|
||||
line += *p++;
|
||||
--size;
|
||||
}
|
||||
|
||||
/* If lasti and addr don't match exactly, we don't want to
|
||||
change the lineno slot on the frame or execute a trace
|
||||
function. Return -1 instead.
|
||||
*/
|
||||
if (addr != lasti)
|
||||
line = -1;
|
||||
|
||||
if (size > 0) {
|
||||
while (--size >= 0) {
|
||||
addr += *p++;
|
||||
if (*p++)
|
||||
break;
|
||||
}
|
||||
bounds->ap_upper = addr;
|
||||
}
|
||||
else {
|
||||
bounds->ap_upper = INT_MAX;
|
||||
}
|
||||
|
||||
return line;
|
||||
}
|
||||
Reference in New Issue
Block a user