summaryrefslogtreecommitdiffstats
path: root/Python/symtable.c
blob: f86fd2fbc802ba021cb308abd7fdeace43cefb5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
#include "Python.h"
#include "compile.h"
#include "symtable.h"
#include "graminit.h"
#include "structmember.h"

/* The compiler uses this function to load a PySymtableEntry object
   for a code block.  Each block is loaded twice, once during the
   symbol table pass and once during the code gen pass.  Entries
   created during the first pass are cached for the second pass, using
   the st_symbols dictionary.  

   The cache is keyed by st_nscopes.  Each code block node in a
   module's parse tree can be assigned a unique id based on the order
   in which the nodes are visited by the compiler.  This strategy
   works so long as the symbol table and codegen passes visit the same
   nodes in the same order.
*/


PyObject *
PySymtableEntry_New(struct symtable *st, char *name, int type, int lineno)
{
	PySymtableEntryObject *ste = NULL;
	PyObject *k, *v;

	k = PyInt_FromLong(st->st_nscopes++);
	if (k == NULL)
		goto fail;
	v = PyDict_GetItem(st->st_symbols, k);
	if (v) {
		Py_DECREF(k);
		Py_INCREF(v);
		return v;
	}
	
	ste = (PySymtableEntryObject *)PyObject_New(PySymtableEntryObject,
						    &PySymtableEntry_Type);
	ste->ste_table = st;
	ste->ste_id = k;

	v = PyString_FromString(name);
	if (v == NULL)
		goto fail;
	ste->ste_name = v;
	
	v = PyDict_New();
	if (v == NULL)
	    goto fail;
	ste->ste_symbols = v;

	v = PyList_New(0);
	if (v == NULL)
	    goto fail;
	ste->ste_varnames = v;

	v = PyList_New(0);
	if (v == NULL)
	    goto fail;
	ste->ste_children = v;

	ste->ste_optimized = 0;
	ste->ste_opt_lineno = 0;
	ste->ste_tmpname = 0;
	ste->ste_lineno = lineno;
	switch (type) {
	case funcdef:
	case lambdef:
		ste->ste_type = TYPE_FUNCTION;
		break;
	case classdef:
		ste->ste_type = TYPE_CLASS;
		break;
	case single_input:
	case eval_input:
	case file_input:
		ste->ste_type = TYPE_MODULE;
		break;
	}

	if (st->st_cur == NULL)
		ste->ste_nested = 0;
	else if (st->st_cur->ste_nested 
		 || st->st_cur->ste_type == TYPE_FUNCTION)
		ste->ste_nested = 1;
	else
		ste->ste_nested = 0;
	ste->ste_child_free = 0;
	ste->ste_generator = 0;

	if (PyDict_SetItem(st->st_symbols, ste->ste_id, (PyObject *)ste) < 0)
	    goto fail;
	
	return (PyObject *)ste;
 fail:
	Py_XDECREF(ste);
	return NULL;
}

static PyObject *
ste_repr(PySymtableEntryObject *ste)
{
	char buf[256];

	PyOS_snprintf(buf, sizeof(buf),
		      "<symtable entry %.100s(%ld), line %d>",
		      PyString_AS_STRING(ste->ste_name),
		      PyInt_AS_LONG(ste->ste_id),
		      ste->ste_lineno);
	return PyString_FromString(buf);
}

static void
ste_dealloc(PySymtableEntryObject *ste)
{
	ste->ste_table = NULL;
	Py_XDECREF(ste->ste_id);
	Py_XDECREF(ste->ste_name);
	Py_XDECREF(ste->ste_symbols);
	Py_XDECREF(ste->ste_varnames);
	Py_XDECREF(ste->ste_children);
	PyObject_Del(ste);
}

#define OFF(x) offsetof(PySymtableEntryObject, x)

static PyMemberDef ste_memberlist[] = {
	{"id",       T_OBJECT, OFF(ste_id), READONLY},
	{"name",     T_OBJECT, OFF(ste_name), READONLY},
	{"symbols",  T_OBJECT, OFF(ste_symbols), READONLY},
	{"varnames", T_OBJECT, OFF(ste_varnames), READONLY},
	{"children", T_OBJECT, OFF(ste_children), READONLY},
	{"type",     T_INT,    OFF(ste_type), READONLY},
	{"lineno",   T_INT,    OFF(ste_lineno), READONLY},
	{"optimized",T_INT,    OFF(ste_optimized), READONLY},
	{"nested",   T_INT,    OFF(ste_nested), READONLY},
	{NULL}
};

PyTypeObject PySymtableEntry_Type = {
	PyObject_HEAD_INIT(&PyType_Type)
	0,
	"symtable entry",
	sizeof(PySymtableEntryObject),
	0,
	(destructor)ste_dealloc,                /* tp_dealloc */
	0,                                      /* tp_print */
	0,			               /* tp_getattr */
	0,					/* tp_setattr */
	0,			                /* tp_compare */
	(reprfunc)ste_repr,			/* tp_repr */
	0,					/* tp_as_number */
	0,			                /* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,					/* tp_hash */
	0,					/* tp_call */
	0,					/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT,	                /* tp_flags */
 	0,					/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	0,					/* tp_methods */
	ste_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 */
	0,					/* tp_new */
};