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Fix compilation error in debug mode.
[python.git] / Python / compile.c
bloba35cda1fe88dc1525eb2629e86b511485a5876df
1 /*
2 * This file compiles an abstract syntax tree (AST) into Python bytecode.
3 *
4 * The primary entry point is PyAST_Compile(), which returns a
5 * PyCodeObject. The compiler makes several passes to build the code
6 * object:
7 * 1. Checks for future statements. See future.c
8 * 2. Builds a symbol table. See symtable.c.
9 * 3. Generate code for basic blocks. See compiler_mod() in this file.
10 * 4. Assemble the basic blocks into final code. See assemble() in
11 * this file.
12 * 5. Optimize the byte code (peephole optimizations). See peephole.c
13 *
14 * Note that compiler_mod() suggests module, but the module ast type
15 * (mod_ty) has cases for expressions and interactive statements.
16 *
17 * CAUTION: The VISIT_* macros abort the current function when they
18 * encounter a problem. So don't invoke them when there is memory
19 * which needs to be released. Code blocks are OK, as the compiler
20 * structure takes care of releasing those. Use the arena to manage
21 * objects.
22 */
23
24 #include "Python.h"
25
26 #include "Python-ast.h"
27 #include "node.h"
28 #include "pyarena.h"
29 #include "ast.h"
30 #include "code.h"
31 #include "compile.h"
32 #include "symtable.h"
33 #include "opcode.h"
34
35 int Py_OptimizeFlag = 0;
36
37 #define DEFAULT_BLOCK_SIZE 16
38 #define DEFAULT_BLOCKS 8
39 #define DEFAULT_CODE_SIZE 128
40 #define DEFAULT_LNOTAB_SIZE 16
41
42 struct instr {
43 unsigned i_jabs : 1;
44 unsigned i_jrel : 1;
45 unsigned i_hasarg : 1;
46 unsigned char i_opcode;
47 int i_oparg;
48 struct basicblock_ *i_target; /* target block (if jump instruction) */
49 int i_lineno;
50 };
51
52 typedef struct basicblock_ {
53 /* Each basicblock in a compilation unit is linked via b_list in the
54 reverse order that the block are allocated. b_list points to the next
55 block, not to be confused with b_next, which is next by control flow. */
56 struct basicblock_ *b_list;
57 /* number of instructions used */
58 int b_iused;
59 /* length of instruction array (b_instr) */
60 int b_ialloc;
61 /* pointer to an array of instructions, initially NULL */
62 struct instr *b_instr;
63 /* If b_next is non-NULL, it is a pointer to the next
64 block reached by normal control flow. */
65 struct basicblock_ *b_next;
66 /* b_seen is used to perform a DFS of basicblocks. */
67 unsigned b_seen : 1;
68 /* b_return is true if a RETURN_VALUE opcode is inserted. */
69 unsigned b_return : 1;
70 /* depth of stack upon entry of block, computed by stackdepth() */
71 int b_startdepth;
72 /* instruction offset for block, computed by assemble_jump_offsets() */
73 int b_offset;
74 } basicblock;
75
76 /* fblockinfo tracks the current frame block.
77
78 A frame block is used to handle loops, try/except, and try/finally.
79 It's called a frame block to distinguish it from a basic block in the
80 compiler IR.
81 */
82
83 enum fblocktype { LOOP, EXCEPT, FINALLY_TRY, FINALLY_END };
84
85 struct fblockinfo {
86 enum fblocktype fb_type;
87 basicblock *fb_block;
88 };
89
90 /* The following items change on entry and exit of code blocks.
91 They must be saved and restored when returning to a block.
92 */
93 struct compiler_unit {
94 PySTEntryObject *u_ste;
95
96 PyObject *u_name;
97 /* The following fields are dicts that map objects to
98 the index of them in co_XXX. The index is used as
99 the argument for opcodes that refer to those collections.
100 */
101 PyObject *u_consts; /* all constants */
102 PyObject *u_names; /* all names */
103 PyObject *u_varnames; /* local variables */
104 PyObject *u_cellvars; /* cell variables */
105 PyObject *u_freevars; /* free variables */
106
107 PyObject *u_private; /* for private name mangling */
108
109 int u_argcount; /* number of arguments for block */
110 /* Pointer to the most recently allocated block. By following b_list
111 members, you can reach all early allocated blocks. */
112 basicblock *u_blocks;
113 basicblock *u_curblock; /* pointer to current block */
114
115 int u_nfblocks;
116 struct fblockinfo u_fblock[CO_MAXBLOCKS];
117
118 int u_firstlineno; /* the first lineno of the block */
119 int u_lineno; /* the lineno for the current stmt */
120 bool u_lineno_set; /* boolean to indicate whether instr
121 has been generated with current lineno */
122 };
123
124 /* This struct captures the global state of a compilation.
125
126 The u pointer points to the current compilation unit, while units
127 for enclosing blocks are stored in c_stack. The u and c_stack are
128 managed by compiler_enter_scope() and compiler_exit_scope().
129 */
130
131 struct compiler {
132 const char *c_filename;
133 struct symtable *c_st;
134 PyFutureFeatures *c_future; /* pointer to module's __future__ */
135 PyCompilerFlags *c_flags;
136
137 int c_interactive; /* true if in interactive mode */
138 int c_nestlevel;
139
140 struct compiler_unit *u; /* compiler state for current block */
141 PyObject *c_stack; /* Python list holding compiler_unit ptrs */
142 PyArena *c_arena; /* pointer to memory allocation arena */
143 };
144
145 static int compiler_enter_scope(struct compiler *, identifier, void *, int);
146 static void compiler_free(struct compiler *);
147 static basicblock *compiler_new_block(struct compiler *);
148 static int compiler_next_instr(struct compiler *, basicblock *);
149 static int compiler_addop(struct compiler *, int);
150 static int compiler_addop_o(struct compiler *, int, PyObject *, PyObject *);
151 static int compiler_addop_i(struct compiler *, int, int);
152 static int compiler_addop_j(struct compiler *, int, basicblock *, int);
153 static basicblock *compiler_use_new_block(struct compiler *);
154 static int compiler_error(struct compiler *, const char *);
155 static int compiler_nameop(struct compiler *, identifier, expr_context_ty);
156
157 static PyCodeObject *compiler_mod(struct compiler *, mod_ty);
158 static int compiler_visit_stmt(struct compiler *, stmt_ty);
159 static int compiler_visit_keyword(struct compiler *, keyword_ty);
160 static int compiler_visit_expr(struct compiler *, expr_ty);
161 static int compiler_augassign(struct compiler *, stmt_ty);
162 static int compiler_visit_slice(struct compiler *, slice_ty,
163 expr_context_ty);
164
165 static int compiler_push_fblock(struct compiler *, enum fblocktype,
166 basicblock *);
167 static void compiler_pop_fblock(struct compiler *, enum fblocktype,
168 basicblock *);
169 /* Returns true if there is a loop on the fblock stack. */
170 static int compiler_in_loop(struct compiler *);
171
172 static int inplace_binop(struct compiler *, operator_ty);
173 static int expr_constant(expr_ty e);
174
175 static int compiler_with(struct compiler *, stmt_ty);
176
177 static PyCodeObject *assemble(struct compiler *, int addNone);
178 static PyObject *__doc__;
179
180 PyObject *
181 _Py_Mangle(PyObject *privateobj, PyObject *ident)
182 {
183 /* Name mangling: __private becomes _classname__private.
184 This is independent from how the name is used. */
185 const char *p, *name = PyString_AsString(ident);
186 char *buffer;
187 size_t nlen, plen;
188 if (privateobj == NULL || !PyString_Check(privateobj) ||
189 name == NULL || name[0] != '_' || name[1] != '_') {
190 Py_INCREF(ident);
191 return ident;
192 }
193 p = PyString_AsString(privateobj);
194 nlen = strlen(name);
195 /* Don't mangle __id__ or names with dots.
196
197 The only time a name with a dot can occur is when
198 we are compiling an import statement that has a
199 package name.
200
201 TODO(jhylton): Decide whether we want to support
202 mangling of the module name, e.g. __M.X.
203 */
204 if ((name[nlen-1] == '_' && name[nlen-2] == '_')
205 || strchr(name, '.')) {
206 Py_INCREF(ident);
207 return ident; /* Don't mangle __whatever__ */
208 }
209 /* Strip leading underscores from class name */
210 while (*p == '_')
211 p++;
212 if (*p == '\0') {
213 Py_INCREF(ident);
214 return ident; /* Don't mangle if class is just underscores */
215 }
216 plen = strlen(p);
217
218 assert(1 <= PY_SSIZE_T_MAX - nlen);
219 assert(1 + nlen <= PY_SSIZE_T_MAX - plen);
220
221 ident = PyString_FromStringAndSize(NULL, 1 + nlen + plen);
222 if (!ident)
223 return 0;
224 /* ident = "_" + p[:plen] + name # i.e. 1+plen+nlen bytes */
225 buffer = PyString_AS_STRING(ident);
226 buffer[0] = '_';
227 strncpy(buffer+1, p, plen);
228 strcpy(buffer+1+plen, name);
229 return ident;
230 }
231
232 static int
233 compiler_init(struct compiler *c)
234 {
235 memset(c, 0, sizeof(struct compiler));
236
237 c->c_stack = PyList_New(0);
238 if (!c->c_stack)
239 return 0;
240
241 return 1;
242 }
243
244 PyCodeObject *
245 PyAST_Compile(mod_ty mod, const char *filename, PyCompilerFlags *flags,
246 PyArena *arena)
247 {
248 struct compiler c;
249 PyCodeObject *co = NULL;
250 PyCompilerFlags local_flags;
251 int merged;
252
253 if (!__doc__) {
254 __doc__ = PyString_InternFromString("__doc__");
255 if (!__doc__)
256 return NULL;
257 }
258
259 if (!compiler_init(&c))
260 return NULL;
261 c.c_filename = filename;
262 c.c_arena = arena;
263 c.c_future = PyFuture_FromAST(mod, filename);
264 if (c.c_future == NULL)
265 goto finally;
266 if (!flags) {
267 local_flags.cf_flags = 0;
268 flags = &local_flags;
269 }
270 merged = c.c_future->ff_features | flags->cf_flags;
271 c.c_future->ff_features = merged;
272 flags->cf_flags = merged;
273 c.c_flags = flags;
274 c.c_nestlevel = 0;
275
276 c.c_st = PySymtable_Build(mod, filename, c.c_future);
277 if (c.c_st == NULL) {
278 if (!PyErr_Occurred())
279 PyErr_SetString(PyExc_SystemError, "no symtable");
280 goto finally;
281 }
282
283 co = compiler_mod(&c, mod);
284
285 finally:
286 compiler_free(&c);
287 assert(co || PyErr_Occurred());
288 return co;
289 }
290
291 PyCodeObject *
292 PyNode_Compile(struct _node *n, const char *filename)
293 {
294 PyCodeObject *co = NULL;
295 mod_ty mod;
296 PyArena *arena = PyArena_New();
297 if (!arena)
298 return NULL;
299 mod = PyAST_FromNode(n, NULL, filename, arena);
300 if (mod)
301 co = PyAST_Compile(mod, filename, NULL, arena);
302 PyArena_Free(arena);
303 return co;
304 }
305
306 static void
307 compiler_free(struct compiler *c)
308 {
309 if (c->c_st)
310 PySymtable_Free(c->c_st);
311 if (c->c_future)
312 PyObject_Free(c->c_future);
313 Py_DECREF(c->c_stack);
314 }
315
316 static PyObject *
317 list2dict(PyObject *list)
318 {
319 Py_ssize_t i, n;
320 PyObject *v, *k;
321 PyObject *dict = PyDict_New();
322 if (!dict) return NULL;
323
324 n = PyList_Size(list);
325 for (i = 0; i < n; i++) {
326 v = PyInt_FromLong(i);
327 if (!v) {
328 Py_DECREF(dict);
329 return NULL;
330 }
331 k = PyList_GET_ITEM(list, i);
332 k = PyTuple_Pack(2, k, k->ob_type);
333 if (k == NULL || PyDict_SetItem(dict, k, v) < 0) {
334 Py_XDECREF(k);
335 Py_DECREF(v);
336 Py_DECREF(dict);
337 return NULL;
338 }
339 Py_DECREF(k);
340 Py_DECREF(v);
341 }
342 return dict;
343 }
344
345 /* Return new dict containing names from src that match scope(s).
346
347 src is a symbol table dictionary. If the scope of a name matches
348 either scope_type or flag is set, insert it into the new dict. The
349 values are integers, starting at offset and increasing by one for
350 each key.
351 */
352
353 static PyObject *
354 dictbytype(PyObject *src, int scope_type, int flag, int offset)
355 {
356 Py_ssize_t pos = 0, i = offset, scope;
357 PyObject *k, *v, *dest = PyDict_New();
358
359 assert(offset >= 0);
360 if (dest == NULL)
361 return NULL;
362
363 while (PyDict_Next(src, &pos, &k, &v)) {
364 /* XXX this should probably be a macro in symtable.h */
365 assert(PyInt_Check(v));
366 scope = (PyInt_AS_LONG(v) >> SCOPE_OFF) & SCOPE_MASK;
367
368 if (scope == scope_type || PyInt_AS_LONG(v) & flag) {
369 PyObject *tuple, *item = PyInt_FromLong(i);
370 if (item == NULL) {
371 Py_DECREF(dest);
372 return NULL;
373 }
374 i++;
375 tuple = PyTuple_Pack(2, k, k->ob_type);
376 if (!tuple || PyDict_SetItem(dest, tuple, item) < 0) {
377 Py_DECREF(item);
378 Py_DECREF(dest);
379 Py_XDECREF(tuple);
380 return NULL;
381 }
382 Py_DECREF(item);
383 Py_DECREF(tuple);
384 }
385 }
386 return dest;
387 }
388
389 static void
390 compiler_unit_check(struct compiler_unit *u)
391 {
392 basicblock *block;
393 for (block = u->u_blocks; block != NULL; block = block->b_list) {
394 assert((void *)block != (void *)0xcbcbcbcb);
395 assert((void *)block != (void *)0xfbfbfbfb);
396 assert((void *)block != (void *)0xdbdbdbdb);
397 if (block->b_instr != NULL) {
398 assert(block->b_ialloc > 0);
399 assert(block->b_iused > 0);
400 assert(block->b_ialloc >= block->b_iused);
401 }
402 else {
403 assert (block->b_iused == 0);
404 assert (block->b_ialloc == 0);
405 }
406 }
407 }
408
409 static void
410 compiler_unit_free(struct compiler_unit *u)
411 {
412 basicblock *b, *next;
413
414 compiler_unit_check(u);
415 b = u->u_blocks;
416 while (b != NULL) {
417 if (b->b_instr)
418 PyObject_Free((void *)b->b_instr);
419 next = b->b_list;
420 PyObject_Free((void *)b);
421 b = next;
422 }
423 Py_CLEAR(u->u_ste);
424 Py_CLEAR(u->u_name);
425 Py_CLEAR(u->u_consts);
426 Py_CLEAR(u->u_names);
427 Py_CLEAR(u->u_varnames);
428 Py_CLEAR(u->u_freevars);
429 Py_CLEAR(u->u_cellvars);
430 Py_CLEAR(u->u_private);
431 PyObject_Free(u);
432 }
433
434 static int
435 compiler_enter_scope(struct compiler *c, identifier name, void *key,
436 int lineno)
437 {
438 struct compiler_unit *u;
439
440 u = (struct compiler_unit *)PyObject_Malloc(sizeof(
441 struct compiler_unit));
442 if (!u) {
443 PyErr_NoMemory();
444 return 0;
445 }
446 memset(u, 0, sizeof(struct compiler_unit));
447 u->u_argcount = 0;
448 u->u_ste = PySymtable_Lookup(c->c_st, key);
449 if (!u->u_ste) {
450 compiler_unit_free(u);
451 return 0;
452 }
453 Py_INCREF(name);
454 u->u_name = name;
455 u->u_varnames = list2dict(u->u_ste->ste_varnames);
456 u->u_cellvars = dictbytype(u->u_ste->ste_symbols, CELL, 0, 0);
457 if (!u->u_varnames || !u->u_cellvars) {
458 compiler_unit_free(u);
459 return 0;
460 }
461
462 u->u_freevars = dictbytype(u->u_ste->ste_symbols, FREE, DEF_FREE_CLASS,
463 PyDict_Size(u->u_cellvars));
464 if (!u->u_freevars) {
465 compiler_unit_free(u);
466 return 0;
467 }
468
469 u->u_blocks = NULL;
470 u->u_nfblocks = 0;
471 u->u_firstlineno = lineno;
472 u->u_lineno = 0;
473 u->u_lineno_set = false;
474 u->u_consts = PyDict_New();
475 if (!u->u_consts) {
476 compiler_unit_free(u);
477 return 0;
478 }
479 u->u_names = PyDict_New();
480 if (!u->u_names) {
481 compiler_unit_free(u);
482 return 0;
483 }
484
485 u->u_private = NULL;
486
487 /* Push the old compiler_unit on the stack. */
488 if (c->u) {
489 PyObject *wrapper = PyCObject_FromVoidPtr(c->u, NULL);
490 if (!wrapper || PyList_Append(c->c_stack, wrapper) < 0) {
491 Py_XDECREF(wrapper);
492 compiler_unit_free(u);
493 return 0;
494 }
495 Py_DECREF(wrapper);
496 u->u_private = c->u->u_private;
497 Py_XINCREF(u->u_private);
498 }
499 c->u = u;
500
501 c->c_nestlevel++;
502 if (compiler_use_new_block(c) == NULL)
503 return 0;
504
505 return 1;
506 }
507
508 static void
509 compiler_exit_scope(struct compiler *c)
510 {
511 int n;
512 PyObject *wrapper;
513
514 c->c_nestlevel--;
515 compiler_unit_free(c->u);
516 /* Restore c->u to the parent unit. */
517 n = PyList_GET_SIZE(c->c_stack) - 1;
518 if (n >= 0) {
519 wrapper = PyList_GET_ITEM(c->c_stack, n);
520 c->u = (struct compiler_unit *)PyCObject_AsVoidPtr(wrapper);
521 assert(c->u);
522 /* we are deleting from a list so this really shouldn't fail */
523 if (PySequence_DelItem(c->c_stack, n) < 0)
524 Py_FatalError("compiler_exit_scope()");
525 compiler_unit_check(c->u);
526 }
527 else
528 c->u = NULL;
529
530 }
531
532 /* Allocate a new block and return a pointer to it.
533 Returns NULL on error.
534 */
535
536 static basicblock *
537 compiler_new_block(struct compiler *c)
538 {
539 basicblock *b;
540 struct compiler_unit *u;
541
542 u = c->u;
543 b = (basicblock *)PyObject_Malloc(sizeof(basicblock));
544 if (b == NULL) {
545 PyErr_NoMemory();
546 return NULL;
547 }
548 memset((void *)b, 0, sizeof(basicblock));
549 /* Extend the singly linked list of blocks with new block. */
550 b->b_list = u->u_blocks;
551 u->u_blocks = b;
552 return b;
553 }
554
555 static basicblock *
556 compiler_use_new_block(struct compiler *c)
557 {
558 basicblock *block = compiler_new_block(c);
559 if (block == NULL)
560 return NULL;
561 c->u->u_curblock = block;
562 return block;
563 }
564
565 static basicblock *
566 compiler_next_block(struct compiler *c)
567 {
568 basicblock *block = compiler_new_block(c);
569 if (block == NULL)
570 return NULL;
571 c->u->u_curblock->b_next = block;
572 c->u->u_curblock = block;
573 return block;
574 }
575
576 static basicblock *
577 compiler_use_next_block(struct compiler *c, basicblock *block)
578 {
579 assert(block != NULL);
580 c->u->u_curblock->b_next = block;
581 c->u->u_curblock = block;
582 return block;
583 }
584
585 /* Returns the offset of the next instruction in the current block's
586 b_instr array. Resizes the b_instr as necessary.
587 Returns -1 on failure.
588 */
589
590 static int
591 compiler_next_instr(struct compiler *c, basicblock *b)
592 {
593 assert(b != NULL);
594 if (b->b_instr == NULL) {
595 b->b_instr = (struct instr *)PyObject_Malloc(
596 sizeof(struct instr) * DEFAULT_BLOCK_SIZE);
597 if (b->b_instr == NULL) {
598 PyErr_NoMemory();
599 return -1;
600 }
601 b->b_ialloc = DEFAULT_BLOCK_SIZE;
602 memset((char *)b->b_instr, 0,
603 sizeof(struct instr) * DEFAULT_BLOCK_SIZE);
604 }
605 else if (b->b_iused == b->b_ialloc) {
606 struct instr *tmp;
607 size_t oldsize, newsize;
608 oldsize = b->b_ialloc * sizeof(struct instr);
609 newsize = oldsize << 1;
610
611 if (oldsize > (PY_SIZE_MAX >> 1)) {
612 PyErr_NoMemory();
613 return -1;
614 }
615
616 if (newsize == 0) {
617 PyErr_NoMemory();
618 return -1;
619 }
620 b->b_ialloc <<= 1;
621 tmp = (struct instr *)PyObject_Realloc(
622 (void *)b->b_instr, newsize);
623 if (tmp == NULL) {
624 PyErr_NoMemory();
625 return -1;
626 }
627 b->b_instr = tmp;
628 memset((char *)b->b_instr + oldsize, 0, newsize - oldsize);
629 }
630 return b->b_iused++;
631 }
632
633 /* Set the i_lineno member of the instruction at offset off if the
634 line number for the current expression/statement has not
635 already been set. If it has been set, the call has no effect.
636
637 The line number is reset in the following cases:
638 - when entering a new scope
639 - on each statement
640 - on each expression that start a new line
641 - before the "except" clause
642 - before the "for" and "while" expressions
643 */
644
645 static void
646 compiler_set_lineno(struct compiler *c, int off)
647 {
648 basicblock *b;
649 if (c->u->u_lineno_set)
650 return;
651 c->u->u_lineno_set = true;
652 b = c->u->u_curblock;
653 b->b_instr[off].i_lineno = c->u->u_lineno;
654 }
655
656 static int
657 opcode_stack_effect(int opcode, int oparg)
658 {
659 switch (opcode) {
660 case POP_TOP:
661 return -1;
662 case ROT_TWO:
663 case ROT_THREE:
664 return 0;
665 case DUP_TOP:
666 return 1;
667 case ROT_FOUR:
668 return 0;
669
670 case UNARY_POSITIVE:
671 case UNARY_NEGATIVE:
672 case UNARY_NOT:
673 case UNARY_CONVERT:
674 case UNARY_INVERT:
675 return 0;
676
677 case LIST_APPEND:
678 return -1;
679
680 case BINARY_POWER:
681 case BINARY_MULTIPLY:
682 case BINARY_DIVIDE:
683 case BINARY_MODULO:
684 case BINARY_ADD:
685 case BINARY_SUBTRACT:
686 case BINARY_SUBSCR:
687 case BINARY_FLOOR_DIVIDE:
688 case BINARY_TRUE_DIVIDE:
689 return -1;
690 case INPLACE_FLOOR_DIVIDE:
691 case INPLACE_TRUE_DIVIDE:
692 return -1;
693
694 case SLICE+0:
695 return 0;
696 case SLICE+1:
697 return -1;
698 case SLICE+2:
699 return -1;
700 case SLICE+3:
701 return -2;
702
703 case STORE_SLICE+0:
704 return -2;
705 case STORE_SLICE+1:
706 return -3;
707 case STORE_SLICE+2:
708 return -3;
709 case STORE_SLICE+3:
710 return -4;
711
712 case DELETE_SLICE+0:
713 return -1;
714 case DELETE_SLICE+1:
715 return -2;
716 case DELETE_SLICE+2:
717 return -2;
718 case DELETE_SLICE+3:
719 return -3;
720
721 case INPLACE_ADD:
722 case INPLACE_SUBTRACT:
723 case INPLACE_MULTIPLY:
724 case INPLACE_DIVIDE:
725 case INPLACE_MODULO:
726 return -1;
727 case STORE_SUBSCR:
728 return -3;
729 case STORE_MAP:
730 return -2;
731 case DELETE_SUBSCR:
732 return -2;
733
734 case BINARY_LSHIFT:
735 case BINARY_RSHIFT:
736 case BINARY_AND:
737 case BINARY_XOR:
738 case BINARY_OR:
739 return -1;
740 case INPLACE_POWER:
741 return -1;
742 case GET_ITER:
743 return 0;
744
745 case PRINT_EXPR:
746 return -1;
747 case PRINT_ITEM:
748 return -1;
749 case PRINT_NEWLINE:
750 return 0;
751 case PRINT_ITEM_TO:
752 return -2;
753 case PRINT_NEWLINE_TO:
754 return -1;
755 case INPLACE_LSHIFT:
756 case INPLACE_RSHIFT:
757 case INPLACE_AND:
758 case INPLACE_XOR:
759 case INPLACE_OR:
760 return -1;
761 case BREAK_LOOP:
762 return 0;
763 case SETUP_WITH:
764 return 4;
765 case WITH_CLEANUP:
766 return -1; /* XXX Sometimes more */
767 case LOAD_LOCALS:
768 return 1;
769 case RETURN_VALUE:
770 return -1;
771 case IMPORT_STAR:
772 return -1;
773 case EXEC_STMT:
774 return -3;
775 case YIELD_VALUE:
776 return 0;
777
778 case POP_BLOCK:
779 return 0;
780 case END_FINALLY:
781 return -3; /* or -1 or -2 if no exception occurred or
782 return/break/continue */
783 case BUILD_CLASS:
784 return -2;
785
786 case STORE_NAME:
787 return -1;
788 case DELETE_NAME:
789 return 0;
790 case UNPACK_SEQUENCE:
791 return oparg-1;
792 case FOR_ITER:
793 return 1; /* or -1, at end of iterator */
794
795 case STORE_ATTR:
796 return -2;
797 case DELETE_ATTR:
798 return -1;
799 case STORE_GLOBAL:
800 return -1;
801 case DELETE_GLOBAL:
802 return 0;
803 case DUP_TOPX:
804 return oparg;
805 case LOAD_CONST:
806 return 1;
807 case LOAD_NAME:
808 return 1;
809 case BUILD_TUPLE:
810 case BUILD_LIST:
811 return 1-oparg;
812 case BUILD_MAP:
813 return 1;
814 case LOAD_ATTR:
815 return 0;
816 case COMPARE_OP:
817 return -1;
818 case IMPORT_NAME:
819 return -1;
820 case IMPORT_FROM:
821 return 1;
822
823 case JUMP_FORWARD:
824 case JUMP_IF_TRUE_OR_POP: /* -1 if jump not taken */
825 case JUMP_IF_FALSE_OR_POP: /* "" */
826 case JUMP_ABSOLUTE:
827 return 0;
828
829 case POP_JUMP_IF_FALSE:
830 case POP_JUMP_IF_TRUE:
831 return -1;
832
833 case LOAD_GLOBAL:
834 return 1;
835
836 case CONTINUE_LOOP:
837 return 0;
838 case SETUP_LOOP:
839 case SETUP_EXCEPT:
840 case SETUP_FINALLY:
841 return 0;
842
843 case LOAD_FAST:
844 return 1;
845 case STORE_FAST:
846 return -1;
847 case DELETE_FAST:
848 return 0;
849
850 case RAISE_VARARGS:
851 return -oparg;
852 #define NARGS(o) (((o) % 256) + 2*((o) / 256))
853 case CALL_FUNCTION:
854 return -NARGS(oparg);
855 case CALL_FUNCTION_VAR:
856 case CALL_FUNCTION_KW:
857 return -NARGS(oparg)-1;
858 case CALL_FUNCTION_VAR_KW:
859 return -NARGS(oparg)-2;
860 #undef NARGS
861 case MAKE_FUNCTION:
862 return -oparg;
863 case BUILD_SLICE:
864 if (oparg == 3)
865 return -2;
866 else
867 return -1;
868
869 case MAKE_CLOSURE:
870 return -oparg-1;
871 case LOAD_CLOSURE:
872 return 1;
873 case LOAD_DEREF:
874 return 1;
875 case STORE_DEREF:
876 return -1;
877 default:
878 fprintf(stderr, "opcode = %d\n", opcode);
879 Py_FatalError("opcode_stack_effect()");
880
881 }
882 return 0; /* not reachable */
883 }
884
885 /* Add an opcode with no argument.
886 Returns 0 on failure, 1 on success.
887 */
888
889 static int
890 compiler_addop(struct compiler *c, int opcode)
891 {
892 basicblock *b;
893 struct instr *i;
894 int off;
895 off = compiler_next_instr(c, c->u->u_curblock);
896 if (off < 0)
897 return 0;
898 b = c->u->u_curblock;
899 i = &b->b_instr[off];
900 i->i_opcode = opcode;
901 i->i_hasarg = 0;
902 if (opcode == RETURN_VALUE)
903 b->b_return = 1;
904 compiler_set_lineno(c, off);
905 return 1;
906 }
907
908 static int
909 compiler_add_o(struct compiler *c, PyObject *dict, PyObject *o)
910 {
911 PyObject *t, *v;
912 Py_ssize_t arg;
913 unsigned char *p;
914 double d;
915
916 /* necessary to make sure types aren't coerced (e.g., int and long) */
917 /* _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms */
918 if (PyFloat_Check(o)) {
919 d = PyFloat_AS_DOUBLE(o);
920 p = (unsigned char*) &d;
921 /* all we need is to make the tuple different in either the 0.0
922 * or -0.0 case from all others, just to avoid the "coercion".
923 */
924 if (*p==0 && p[sizeof(double)-1]==0)
925 t = PyTuple_Pack(3, o, o->ob_type, Py_None);
926 else
927 t = PyTuple_Pack(2, o, o->ob_type);
928 }
929 #ifndef WITHOUT_COMPLEX
930 else if (PyComplex_Check(o)) {
931 Py_complex z;
932 int real_part_zero, imag_part_zero;
933 unsigned char *q;
934 /* complex case is even messier: we need to make complex(x,
935 0.) different from complex(x, -0.) and complex(0., y)
936 different from complex(-0., y), for any x and y. In
937 particular, all four complex zeros should be
938 distinguished.*/
939 z = PyComplex_AsCComplex(o);
940 p = (unsigned char*) &(z.real);
941 q = (unsigned char*) &(z.imag);
942 /* all that matters here is that on IEEE platforms
943 real_part_zero will be true if z.real == 0., and false if
944 z.real == -0. In fact, real_part_zero will also be true
945 for some other rarely occurring nonzero floats, but this
946 doesn't matter. Similar comments apply to
947 imag_part_zero. */
948 real_part_zero = *p==0 && p[sizeof(double)-1]==0;
949 imag_part_zero = *q==0 && q[sizeof(double)-1]==0;
950 if (real_part_zero && imag_part_zero) {
951 t = PyTuple_Pack(4, o, o->ob_type, Py_True, Py_True);
952 }
953 else if (real_part_zero && !imag_part_zero) {
954 t = PyTuple_Pack(4, o, o->ob_type, Py_True, Py_False);
955 }
956 else if (!real_part_zero && imag_part_zero) {
957 t = PyTuple_Pack(4, o, o->ob_type, Py_False, Py_True);
958 }
959 else {
960 t = PyTuple_Pack(2, o, o->ob_type);
961 }
962 }
963 #endif /* WITHOUT_COMPLEX */
964 else {
965 t = PyTuple_Pack(2, o, o->ob_type);
966 }
967 if (t == NULL)
968 return -1;
969
970 v = PyDict_GetItem(dict, t);
971 if (!v) {
972 arg = PyDict_Size(dict);
973 v = PyInt_FromLong(arg);
974 if (!v) {
975 Py_DECREF(t);
976 return -1;
977 }
978 if (PyDict_SetItem(dict, t, v) < 0) {
979 Py_DECREF(t);
980 Py_DECREF(v);
981 return -1;
982 }
983 Py_DECREF(v);
984 }
985 else
986 arg = PyInt_AsLong(v);
987 Py_DECREF(t);
988 return arg;
989 }
990
991 static int
992 compiler_addop_o(struct compiler *c, int opcode, PyObject *dict,
993 PyObject *o)
994 {
995 int arg = compiler_add_o(c, dict, o);
996 if (arg < 0)
997 return 0;
998 return compiler_addop_i(c, opcode, arg);
999 }
1000
1001 static int
1002 compiler_addop_name(struct compiler *c, int opcode, PyObject *dict,
1003 PyObject *o)
1004 {
1005 int arg;
1006 PyObject *mangled = _Py_Mangle(c->u->u_private, o);
1007 if (!mangled)
1008 return 0;
1009 arg = compiler_add_o(c, dict, mangled);
1010 Py_DECREF(mangled);
1011 if (arg < 0)
1012 return 0;
1013 return compiler_addop_i(c, opcode, arg);
1014 }
1015
1016 /* Add an opcode with an integer argument.
1017 Returns 0 on failure, 1 on success.
1018 */
1019
1020 static int
1021 compiler_addop_i(struct compiler *c, int opcode, int oparg)
1022 {
1023 struct instr *i;
1024 int off;
1025 off = compiler_next_instr(c, c->u->u_curblock);
1026 if (off < 0)
1027 return 0;
1028 i = &c->u->u_curblock->b_instr[off];
1029 i->i_opcode = opcode;
1030 i->i_oparg = oparg;
1031 i->i_hasarg = 1;
1032 compiler_set_lineno(c, off);
1033 return 1;
1034 }
1035
1036 static int
1037 compiler_addop_j(struct compiler *c, int opcode, basicblock *b, int absolute)
1038 {
1039 struct instr *i;
1040 int off;
1041
1042 assert(b != NULL);
1043 off = compiler_next_instr(c, c->u->u_curblock);
1044 if (off < 0)
1045 return 0;
1046 i = &c->u->u_curblock->b_instr[off];
1047 i->i_opcode = opcode;
1048 i->i_target = b;
1049 i->i_hasarg = 1;
1050 if (absolute)
1051 i->i_jabs = 1;
1052 else
1053 i->i_jrel = 1;
1054 compiler_set_lineno(c, off);
1055 return 1;
1056 }
1057
1058 /* The distinction between NEW_BLOCK and NEXT_BLOCK is subtle. (I'd
1059 like to find better names.) NEW_BLOCK() creates a new block and sets
1060 it as the current block. NEXT_BLOCK() also creates an implicit jump
1061 from the current block to the new block.
1062 */
1063
1064 /* The returns inside these macros make it impossible to decref objects
1065 created in the local function. Local objects should use the arena.
1066 */
1067
1068
1069 #define NEW_BLOCK(C) { \
1070 if (compiler_use_new_block((C)) == NULL) \
1071 return 0; \
1072 }
1073
1074 #define NEXT_BLOCK(C) { \
1075 if (compiler_next_block((C)) == NULL) \
1076 return 0; \
1077 }
1078
1079 #define ADDOP(C, OP) { \
1080 if (!compiler_addop((C), (OP))) \
1081 return 0; \
1082 }
1083
1084 #define ADDOP_IN_SCOPE(C, OP) { \
1085 if (!compiler_addop((C), (OP))) { \
1086 compiler_exit_scope(c); \
1087 return 0; \
1088 } \
1089 }
1090
1091 #define ADDOP_O(C, OP, O, TYPE) { \
1092 if (!compiler_addop_o((C), (OP), (C)->u->u_ ## TYPE, (O))) \
1093 return 0; \
1094 }
1095
1096 #define ADDOP_NAME(C, OP, O, TYPE) { \
1097 if (!compiler_addop_name((C), (OP), (C)->u->u_ ## TYPE, (O))) \
1098 return 0; \
1099 }
1100
1101 #define ADDOP_I(C, OP, O) { \
1102 if (!compiler_addop_i((C), (OP), (O))) \
1103 return 0; \
1104 }
1105
1106 #define ADDOP_JABS(C, OP, O) { \
1107 if (!compiler_addop_j((C), (OP), (O), 1)) \
1108 return 0; \
1109 }
1110
1111 #define ADDOP_JREL(C, OP, O) { \
1112 if (!compiler_addop_j((C), (OP), (O), 0)) \
1113 return 0; \
1114 }
1115
1116 /* VISIT and VISIT_SEQ takes an ASDL type as their second argument. They use
1117 the ASDL name to synthesize the name of the C type and the visit function.
1118 */
1119
1120 #define VISIT(C, TYPE, V) {\
1121 if (!compiler_visit_ ## TYPE((C), (V))) \
1122 return 0; \
1123 }
1124
1125 #define VISIT_IN_SCOPE(C, TYPE, V) {\
1126 if (!compiler_visit_ ## TYPE((C), (V))) { \
1127 compiler_exit_scope(c); \
1128 return 0; \
1129 } \
1130 }
1131
1132 #define VISIT_SLICE(C, V, CTX) {\
1133 if (!compiler_visit_slice((C), (V), (CTX))) \
1134 return 0; \
1135 }
1136
1137 #define VISIT_SEQ(C, TYPE, SEQ) { \
1138 int _i; \
1139 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
1140 for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \
1141 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \
1142 if (!compiler_visit_ ## TYPE((C), elt)) \
1143 return 0; \
1144 } \
1145 }
1146
1147 #define VISIT_SEQ_IN_SCOPE(C, TYPE, SEQ) { \
1148 int _i; \
1149 asdl_seq *seq = (SEQ); /* avoid variable capture */ \
1150 for (_i = 0; _i < asdl_seq_LEN(seq); _i++) { \
1151 TYPE ## _ty elt = (TYPE ## _ty)asdl_seq_GET(seq, _i); \
1152 if (!compiler_visit_ ## TYPE((C), elt)) { \
1153 compiler_exit_scope(c); \
1154 return 0; \
1155 } \
1156 } \
1157 }
1158
1159 static int
1160 compiler_isdocstring(stmt_ty s)
1161 {
1162 if (s->kind != Expr_kind)
1163 return 0;
1164 return s->v.Expr.value->kind == Str_kind;
1165 }
1166
1167 /* Compile a sequence of statements, checking for a docstring. */
1168
1169 static int
1170 compiler_body(struct compiler *c, asdl_seq *stmts)
1171 {
1172 int i = 0;
1173 stmt_ty st;
1174
1175 if (!asdl_seq_LEN(stmts))
1176 return 1;
1177 st = (stmt_ty)asdl_seq_GET(stmts, 0);
1178 if (compiler_isdocstring(st) && Py_OptimizeFlag < 2) {
1179 /* don't generate docstrings if -OO */
1180 i = 1;
1181 VISIT(c, expr, st->v.Expr.value);
1182 if (!compiler_nameop(c, __doc__, Store))
1183 return 0;
1184 }
1185 for (; i < asdl_seq_LEN(stmts); i++)
1186 VISIT(c, stmt, (stmt_ty)asdl_seq_GET(stmts, i));
1187 return 1;
1188 }
1189
1190 static PyCodeObject *
1191 compiler_mod(struct compiler *c, mod_ty mod)
1192 {
1193 PyCodeObject *co;
1194 int addNone = 1;
1195 static PyObject *module;
1196 if (!module) {
1197 module = PyString_InternFromString("<module>");
1198 if (!module)
1199 return NULL;
1200 }
1201 /* Use 0 for firstlineno initially, will fixup in assemble(). */
1202 if (!compiler_enter_scope(c, module, mod, 0))
1203 return NULL;
1204 switch (mod->kind) {
1205 case Module_kind:
1206 if (!compiler_body(c, mod->v.Module.body)) {
1207 compiler_exit_scope(c);
1208 return 0;
1209 }
1210 break;
1211 case Interactive_kind:
1212 c->c_interactive = 1;
1213 VISIT_SEQ_IN_SCOPE(c, stmt,
1214 mod->v.Interactive.body);
1215 break;
1216 case Expression_kind:
1217 VISIT_IN_SCOPE(c, expr, mod->v.Expression.body);
1218 addNone = 0;
1219 break;
1220 case Suite_kind:
1221 PyErr_SetString(PyExc_SystemError,
1222 "suite should not be possible");
1223 return 0;
1224 default:
1225 PyErr_Format(PyExc_SystemError,
1226 "module kind %d should not be possible",
1227 mod->kind);
1228 return 0;
1229 }
1230 co = assemble(c, addNone);
1231 compiler_exit_scope(c);
1232 return co;
1233 }
1234
1235 /* The test for LOCAL must come before the test for FREE in order to
1236 handle classes where name is both local and free. The local var is
1237 a method and the free var is a free var referenced within a method.
1238 */
1239
1240 static int
1241 get_ref_type(struct compiler *c, PyObject *name)
1242 {
1243 int scope = PyST_GetScope(c->u->u_ste, name);
1244 if (scope == 0) {
1245 char buf[350];
1246 PyOS_snprintf(buf, sizeof(buf),
1247 "unknown scope for %.100s in %.100s(%s) in %s\n"
1248 "symbols: %s\nlocals: %s\nglobals: %s",
1249 PyString_AS_STRING(name),
1250 PyString_AS_STRING(c->u->u_name),
1251 PyObject_REPR(c->u->u_ste->ste_id),
1252 c->c_filename,
1253 PyObject_REPR(c->u->u_ste->ste_symbols),
1254 PyObject_REPR(c->u->u_varnames),
1255 PyObject_REPR(c->u->u_names)
1256 );
1257 Py_FatalError(buf);
1258 }
1259
1260 return scope;
1261 }
1262
1263 static int
1264 compiler_lookup_arg(PyObject *dict, PyObject *name)
1265 {
1266 PyObject *k, *v;
1267 k = PyTuple_Pack(2, name, name->ob_type);
1268 if (k == NULL)
1269 return -1;
1270 v = PyDict_GetItem(dict, k);
1271 Py_DECREF(k);
1272 if (v == NULL)
1273 return -1;
1274 return PyInt_AS_LONG(v);
1275 }
1276
1277 static int
1278 compiler_make_closure(struct compiler *c, PyCodeObject *co, int args)
1279 {
1280 int i, free = PyCode_GetNumFree(co);
1281 if (free == 0) {
1282 ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts);
1283 ADDOP_I(c, MAKE_FUNCTION, args);
1284 return 1;
1285 }
1286 for (i = 0; i < free; ++i) {
1287 /* Bypass com_addop_varname because it will generate
1288 LOAD_DEREF but LOAD_CLOSURE is needed.
1289 */
1290 PyObject *name = PyTuple_GET_ITEM(co->co_freevars, i);
1291 int arg, reftype;
1292
1293 /* Special case: If a class contains a method with a
1294 free variable that has the same name as a method,
1295 the name will be considered free *and* local in the
1296 class. It should be handled by the closure, as
1297 well as by the normal name loookup logic.
1298 */
1299 reftype = get_ref_type(c, name);
1300 if (reftype == CELL)
1301 arg = compiler_lookup_arg(c->u->u_cellvars, name);
1302 else /* (reftype == FREE) */
1303 arg = compiler_lookup_arg(c->u->u_freevars, name);
1304 if (arg == -1) {
1305 printf("lookup %s in %s %d %d\n"
1306 "freevars of %s: %s\n",
1307 PyObject_REPR(name),
1308 PyString_AS_STRING(c->u->u_name),
1309 reftype, arg,
1310 PyString_AS_STRING(co->co_name),
1311 PyObject_REPR(co->co_freevars));
1312 Py_FatalError("compiler_make_closure()");
1313 }
1314 ADDOP_I(c, LOAD_CLOSURE, arg);
1315 }
1316 ADDOP_I(c, BUILD_TUPLE, free);
1317 ADDOP_O(c, LOAD_CONST, (PyObject*)co, consts);
1318 ADDOP_I(c, MAKE_CLOSURE, args);
1319 return 1;
1320 }
1321
1322 static int
1323 compiler_decorators(struct compiler *c, asdl_seq* decos)
1324 {
1325 int i;
1326
1327 if (!decos)
1328 return 1;
1329
1330 for (i = 0; i < asdl_seq_LEN(decos); i++) {
1331 VISIT(c, expr, (expr_ty)asdl_seq_GET(decos, i));
1332 }
1333 return 1;
1334 }
1335
1336 static int
1337 compiler_arguments(struct compiler *c, arguments_ty args)
1338 {
1339 int i;
1340 int n = asdl_seq_LEN(args->args);
1341 /* Correctly handle nested argument lists */
1342 for (i = 0; i < n; i++) {
1343 expr_ty arg = (expr_ty)asdl_seq_GET(args->args, i);
1344 if (arg->kind == Tuple_kind) {
1345 PyObject *id = PyString_FromFormat(".%d", i);
1346 if (id == NULL) {
1347 return 0;
1348 }
1349 if (!compiler_nameop(c, id, Load)) {
1350 Py_DECREF(id);
1351 return 0;
1352 }
1353 Py_DECREF(id);
1354 VISIT(c, expr, arg);
1355 }
1356 }
1357 return 1;
1358 }
1359
1360 static int
1361 compiler_function(struct compiler *c, stmt_ty s)
1362 {
1363 PyCodeObject *co;
1364 PyObject *first_const = Py_None;
1365 arguments_ty args = s->v.FunctionDef.args;
1366 asdl_seq* decos = s->v.FunctionDef.decorator_list;
1367 stmt_ty st;
1368 int i, n, docstring;
1369
1370 assert(s->kind == FunctionDef_kind);
1371
1372 if (!compiler_decorators(c, decos))
1373 return 0;
1374 if (args->defaults)
1375 VISIT_SEQ(c, expr, args->defaults);
1376 if (!compiler_enter_scope(c, s->v.FunctionDef.name, (void *)s,
1377 s->lineno))
1378 return 0;
1379
1380 st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, 0);
1381 docstring = compiler_isdocstring(st);
1382 if (docstring && Py_OptimizeFlag < 2)
1383 first_const = st->v.Expr.value->v.Str.s;
1384 if (compiler_add_o(c, c->u->u_consts, first_const) < 0) {
1385 compiler_exit_scope(c);
1386 return 0;
1387 }
1388
1389 /* unpack nested arguments */
1390 compiler_arguments(c, args);
1391
1392 c->u->u_argcount = asdl_seq_LEN(args->args);
1393 n = asdl_seq_LEN(s->v.FunctionDef.body);
1394 /* if there was a docstring, we need to skip the first statement */
1395 for (i = docstring; i < n; i++) {
1396 st = (stmt_ty)asdl_seq_GET(s->v.FunctionDef.body, i);
1397 VISIT_IN_SCOPE(c, stmt, st);
1398 }
1399 co = assemble(c, 1);
1400 compiler_exit_scope(c);
1401 if (co == NULL)
1402 return 0;
1403
1404 compiler_make_closure(c, co, asdl_seq_LEN(args->defaults));
1405 Py_DECREF(co);
1406
1407 for (i = 0; i < asdl_seq_LEN(decos); i++) {
1408 ADDOP_I(c, CALL_FUNCTION, 1);
1409 }
1410
1411 return compiler_nameop(c, s->v.FunctionDef.name, Store);
1412 }
1413
1414 static int
1415 compiler_class(struct compiler *c, stmt_ty s)
1416 {
1417 int n, i;
1418 PyCodeObject *co;
1419 PyObject *str;
1420 asdl_seq* decos = s->v.ClassDef.decorator_list;
1421
1422 if (!compiler_decorators(c, decos))
1423 return 0;
1424
1425 /* push class name on stack, needed by BUILD_CLASS */
1426 ADDOP_O(c, LOAD_CONST, s->v.ClassDef.name, consts);
1427 /* push the tuple of base classes on the stack */
1428 n = asdl_seq_LEN(s->v.ClassDef.bases);
1429 if (n > 0)
1430 VISIT_SEQ(c, expr, s->v.ClassDef.bases);
1431 ADDOP_I(c, BUILD_TUPLE, n);
1432 if (!compiler_enter_scope(c, s->v.ClassDef.name, (void *)s,
1433 s->lineno))
1434 return 0;
1435 Py_XDECREF(c->u->u_private);
1436 c->u->u_private = s->v.ClassDef.name;
1437 Py_INCREF(c->u->u_private);
1438 str = PyString_InternFromString("__name__");
1439 if (!str || !compiler_nameop(c, str, Load)) {
1440 Py_XDECREF(str);
1441 compiler_exit_scope(c);
1442 return 0;
1443 }
1444
1445 Py_DECREF(str);
1446 str = PyString_InternFromString("__module__");
1447 if (!str || !compiler_nameop(c, str, Store)) {
1448 Py_XDECREF(str);
1449 compiler_exit_scope(c);
1450 return 0;
1451 }
1452 Py_DECREF(str);
1453
1454 if (!compiler_body(c, s->v.ClassDef.body)) {
1455 compiler_exit_scope(c);
1456 return 0;
1457 }
1458
1459 ADDOP_IN_SCOPE(c, LOAD_LOCALS);
1460 ADDOP_IN_SCOPE(c, RETURN_VALUE);
1461 co = assemble(c, 1);
1462 compiler_exit_scope(c);
1463 if (co == NULL)
1464 return 0;
1465
1466 compiler_make_closure(c, co, 0);
1467 Py_DECREF(co);
1468
1469 ADDOP_I(c, CALL_FUNCTION, 0);
1470 ADDOP(c, BUILD_CLASS);
1471 /* apply decorators */
1472 for (i = 0; i < asdl_seq_LEN(decos); i++) {
1473 ADDOP_I(c, CALL_FUNCTION, 1);
1474 }
1475 if (!compiler_nameop(c, s->v.ClassDef.name, Store))
1476 return 0;
1477 return 1;
1478 }
1479
1480 static int
1481 compiler_ifexp(struct compiler *c, expr_ty e)
1482 {
1483 basicblock *end, *next;
1484
1485 assert(e->kind == IfExp_kind);
1486 end = compiler_new_block(c);
1487 if (end == NULL)
1488 return 0;
1489 next = compiler_new_block(c);
1490 if (next == NULL)
1491 return 0;
1492 VISIT(c, expr, e->v.IfExp.test);
1493 ADDOP_JABS(c, POP_JUMP_IF_FALSE, next);
1494 VISIT(c, expr, e->v.IfExp.body);
1495 ADDOP_JREL(c, JUMP_FORWARD, end);
1496 compiler_use_next_block(c, next);
1497 VISIT(c, expr, e->v.IfExp.orelse);
1498 compiler_use_next_block(c, end);
1499 return 1;
1500 }
1501
1502 static int
1503 compiler_lambda(struct compiler *c, expr_ty e)
1504 {
1505 PyCodeObject *co;
1506 static identifier name;
1507 arguments_ty args = e->v.Lambda.args;
1508 assert(e->kind == Lambda_kind);
1509
1510 if (!name) {
1511 name = PyString_InternFromString("<lambda>");
1512 if (!name)
1513 return 0;
1514 }
1515
1516 if (args->defaults)
1517 VISIT_SEQ(c, expr, args->defaults);
1518 if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
1519 return 0;
1520
1521 /* unpack nested arguments */
1522 compiler_arguments(c, args);
1523
1524 c->u->u_argcount = asdl_seq_LEN(args->args);
1525 VISIT_IN_SCOPE(c, expr, e->v.Lambda.body);
1526 if (c->u->u_ste->ste_generator) {
1527 ADDOP_IN_SCOPE(c, POP_TOP);
1528 }
1529 else {
1530 ADDOP_IN_SCOPE(c, RETURN_VALUE);
1531 }
1532 co = assemble(c, 1);
1533 compiler_exit_scope(c);
1534 if (co == NULL)
1535 return 0;
1536
1537 compiler_make_closure(c, co, asdl_seq_LEN(args->defaults));
1538 Py_DECREF(co);
1539
1540 return 1;
1541 }
1542
1543 static int
1544 compiler_print(struct compiler *c, stmt_ty s)
1545 {
1546 int i, n;
1547 bool dest;
1548
1549 assert(s->kind == Print_kind);
1550 n = asdl_seq_LEN(s->v.Print.values);
1551 dest = false;
1552 if (s->v.Print.dest) {
1553 VISIT(c, expr, s->v.Print.dest);
1554 dest = true;
1555 }
1556 for (i = 0; i < n; i++) {
1557 expr_ty e = (expr_ty)asdl_seq_GET(s->v.Print.values, i);
1558 if (dest) {
1559 ADDOP(c, DUP_TOP);
1560 VISIT(c, expr, e);
1561 ADDOP(c, ROT_TWO);
1562 ADDOP(c, PRINT_ITEM_TO);
1563 }
1564 else {
1565 VISIT(c, expr, e);
1566 ADDOP(c, PRINT_ITEM);
1567 }
1568 }
1569 if (s->v.Print.nl) {
1570 if (dest)
1571 ADDOP(c, PRINT_NEWLINE_TO)
1572 else
1573 ADDOP(c, PRINT_NEWLINE)
1574 }
1575 else if (dest)
1576 ADDOP(c, POP_TOP);
1577 return 1;
1578 }
1579
1580 static int
1581 compiler_if(struct compiler *c, stmt_ty s)
1582 {
1583 basicblock *end, *next;
1584 int constant;
1585 assert(s->kind == If_kind);
1586 end = compiler_new_block(c);
1587 if (end == NULL)
1588 return 0;
1589
1590 constant = expr_constant(s->v.If.test);
1591 /* constant = 0: "if 0"
1592 * constant = 1: "if 1", "if 2", ...
1593 * constant = -1: rest */
1594 if (constant == 0) {
1595 if (s->v.If.orelse)
1596 VISIT_SEQ(c, stmt, s->v.If.orelse);
1597 } else if (constant == 1) {
1598 VISIT_SEQ(c, stmt, s->v.If.body);
1599 } else {
1600 if (s->v.If.orelse) {
1601 next = compiler_new_block(c);
1602 if (next == NULL)
1603 return 0;
1604 }
1605 else
1606 next = end;
1607 VISIT(c, expr, s->v.If.test);
1608 ADDOP_JABS(c, POP_JUMP_IF_FALSE, next);
1609 VISIT_SEQ(c, stmt, s->v.If.body);
1610 ADDOP_JREL(c, JUMP_FORWARD, end);
1611 if (s->v.If.orelse) {
1612 compiler_use_next_block(c, next);
1613 VISIT_SEQ(c, stmt, s->v.If.orelse);
1614 }
1615 }
1616 compiler_use_next_block(c, end);
1617 return 1;
1618 }
1619
1620 static int
1621 compiler_for(struct compiler *c, stmt_ty s)
1622 {
1623 basicblock *start, *cleanup, *end;
1624
1625 start = compiler_new_block(c);
1626 cleanup = compiler_new_block(c);
1627 end = compiler_new_block(c);
1628 if (start == NULL || end == NULL || cleanup == NULL)
1629 return 0;
1630 ADDOP_JREL(c, SETUP_LOOP, end);
1631 if (!compiler_push_fblock(c, LOOP, start))
1632 return 0;
1633 VISIT(c, expr, s->v.For.iter);
1634 ADDOP(c, GET_ITER);
1635 compiler_use_next_block(c, start);
1636 ADDOP_JREL(c, FOR_ITER, cleanup);
1637 VISIT(c, expr, s->v.For.target);
1638 VISIT_SEQ(c, stmt, s->v.For.body);
1639 ADDOP_JABS(c, JUMP_ABSOLUTE, start);
1640 compiler_use_next_block(c, cleanup);
1641 ADDOP(c, POP_BLOCK);
1642 compiler_pop_fblock(c, LOOP, start);
1643 VISIT_SEQ(c, stmt, s->v.For.orelse);
1644 compiler_use_next_block(c, end);
1645 return 1;
1646 }
1647
1648 static int
1649 compiler_while(struct compiler *c, stmt_ty s)
1650 {
1651 basicblock *loop, *orelse, *end, *anchor = NULL;
1652 int constant = expr_constant(s->v.While.test);
1653
1654 if (constant == 0) {
1655 if (s->v.While.orelse)
1656 VISIT_SEQ(c, stmt, s->v.While.orelse);
1657 return 1;
1658 }
1659 loop = compiler_new_block(c);
1660 end = compiler_new_block(c);
1661 if (constant == -1) {
1662 anchor = compiler_new_block(c);
1663 if (anchor == NULL)
1664 return 0;
1665 }
1666 if (loop == NULL || end == NULL)
1667 return 0;
1668 if (s->v.While.orelse) {
1669 orelse = compiler_new_block(c);
1670 if (orelse == NULL)
1671 return 0;
1672 }
1673 else
1674 orelse = NULL;
1675
1676 ADDOP_JREL(c, SETUP_LOOP, end);
1677 compiler_use_next_block(c, loop);
1678 if (!compiler_push_fblock(c, LOOP, loop))
1679 return 0;
1680 if (constant == -1) {
1681 VISIT(c, expr, s->v.While.test);
1682 ADDOP_JABS(c, POP_JUMP_IF_FALSE, anchor);
1683 }
1684 VISIT_SEQ(c, stmt, s->v.While.body);
1685 ADDOP_JABS(c, JUMP_ABSOLUTE, loop);
1686
1687 /* XXX should the two POP instructions be in a separate block
1688 if there is no else clause ?
1689 */
1690
1691 if (constant == -1) {
1692 compiler_use_next_block(c, anchor);
1693 ADDOP(c, POP_BLOCK);
1694 }
1695 compiler_pop_fblock(c, LOOP, loop);
1696 if (orelse != NULL) /* what if orelse is just pass? */
1697 VISIT_SEQ(c, stmt, s->v.While.orelse);
1698 compiler_use_next_block(c, end);
1699
1700 return 1;
1701 }
1702
1703 static int
1704 compiler_continue(struct compiler *c)
1705 {
1706 static const char LOOP_ERROR_MSG[] = "'continue' not properly in loop";
1707 static const char IN_FINALLY_ERROR_MSG[] =
1708 "'continue' not supported inside 'finally' clause";
1709 int i;
1710
1711 if (!c->u->u_nfblocks)
1712 return compiler_error(c, LOOP_ERROR_MSG);
1713 i = c->u->u_nfblocks - 1;
1714 switch (c->u->u_fblock[i].fb_type) {
1715 case LOOP:
1716 ADDOP_JABS(c, JUMP_ABSOLUTE, c->u->u_fblock[i].fb_block);
1717 break;
1718 case EXCEPT:
1719 case FINALLY_TRY:
1720 while (--i >= 0 && c->u->u_fblock[i].fb_type != LOOP) {
1721 /* Prevent continue anywhere under a finally
1722 even if hidden in a sub-try or except. */
1723 if (c->u->u_fblock[i].fb_type == FINALLY_END)
1724 return compiler_error(c, IN_FINALLY_ERROR_MSG);
1725 }
1726 if (i == -1)
1727 return compiler_error(c, LOOP_ERROR_MSG);
1728 ADDOP_JABS(c, CONTINUE_LOOP, c->u->u_fblock[i].fb_block);
1729 break;
1730 case FINALLY_END:
1731 return compiler_error(c, IN_FINALLY_ERROR_MSG);
1732 }
1733
1734 return 1;
1735 }
1736
1737 /* Code generated for "try: <body> finally: <finalbody>" is as follows:
1738
1739 SETUP_FINALLY L
1740 <code for body>
1741 POP_BLOCK
1742 LOAD_CONST <None>
1743 L: <code for finalbody>
1744 END_FINALLY
1745
1746 The special instructions use the block stack. Each block
1747 stack entry contains the instruction that created it (here
1748 SETUP_FINALLY), the level of the value stack at the time the
1749 block stack entry was created, and a label (here L).
1750
1751 SETUP_FINALLY:
1752 Pushes the current value stack level and the label
1753 onto the block stack.
1754 POP_BLOCK:
1755 Pops en entry from the block stack, and pops the value
1756 stack until its level is the same as indicated on the
1757 block stack. (The label is ignored.)
1758 END_FINALLY:
1759 Pops a variable number of entries from the *value* stack
1760 and re-raises the exception they specify. The number of
1761 entries popped depends on the (pseudo) exception type.
1762
1763 The block stack is unwound when an exception is raised:
1764 when a SETUP_FINALLY entry is found, the exception is pushed
1765 onto the value stack (and the exception condition is cleared),
1766 and the interpreter jumps to the label gotten from the block
1767 stack.
1768 */
1769
1770 static int
1771 compiler_try_finally(struct compiler *c, stmt_ty s)
1772 {
1773 basicblock *body, *end;
1774 body = compiler_new_block(c);
1775 end = compiler_new_block(c);
1776 if (body == NULL || end == NULL)
1777 return 0;
1778
1779 ADDOP_JREL(c, SETUP_FINALLY, end);
1780 compiler_use_next_block(c, body);
1781 if (!compiler_push_fblock(c, FINALLY_TRY, body))
1782 return 0;
1783 VISIT_SEQ(c, stmt, s->v.TryFinally.body);
1784 ADDOP(c, POP_BLOCK);
1785 compiler_pop_fblock(c, FINALLY_TRY, body);
1786
1787 ADDOP_O(c, LOAD_CONST, Py_None, consts);
1788 compiler_use_next_block(c, end);
1789 if (!compiler_push_fblock(c, FINALLY_END, end))
1790 return 0;
1791 VISIT_SEQ(c, stmt, s->v.TryFinally.finalbody);
1792 ADDOP(c, END_FINALLY);
1793 compiler_pop_fblock(c, FINALLY_END, end);
1794
1795 return 1;
1796 }
1797
1798 /*
1799 Code generated for "try: S except E1, V1: S1 except E2, V2: S2 ...":
1800 (The contents of the value stack is shown in [], with the top
1801 at the right; 'tb' is trace-back info, 'val' the exception's
1802 associated value, and 'exc' the exception.)
1803
1804 Value stack Label Instruction Argument
1805 [] SETUP_EXCEPT L1
1806 [] <code for S>
1807 [] POP_BLOCK
1808 [] JUMP_FORWARD L0
1809
1810 [tb, val, exc] L1: DUP )
1811 [tb, val, exc, exc] <evaluate E1> )
1812 [tb, val, exc, exc, E1] COMPARE_OP EXC_MATCH ) only if E1
1813 [tb, val, exc, 1-or-0] POP_JUMP_IF_FALSE L2 )
1814 [tb, val, exc] POP
1815 [tb, val] <assign to V1> (or POP if no V1)
1816 [tb] POP
1817 [] <code for S1>
1818 JUMP_FORWARD L0
1819
1820 [tb, val, exc] L2: DUP
1821 .............................etc.......................
1822
1823 [tb, val, exc] Ln+1: END_FINALLY # re-raise exception
1824
1825 [] L0: <next statement>
1826
1827 Of course, parts are not generated if Vi or Ei is not present.
1828 */
1829 static int
1830 compiler_try_except(struct compiler *c, stmt_ty s)
1831 {
1832 basicblock *body, *orelse, *except, *end;
1833 int i, n;
1834
1835 body = compiler_new_block(c);
1836 except = compiler_new_block(c);
1837 orelse = compiler_new_block(c);
1838 end = compiler_new_block(c);
1839 if (body == NULL || except == NULL || orelse == NULL || end == NULL)
1840 return 0;
1841 ADDOP_JREL(c, SETUP_EXCEPT, except);
1842 compiler_use_next_block(c, body);
1843 if (!compiler_push_fblock(c, EXCEPT, body))
1844 return 0;
1845 VISIT_SEQ(c, stmt, s->v.TryExcept.body);
1846 ADDOP(c, POP_BLOCK);
1847 compiler_pop_fblock(c, EXCEPT, body);
1848 ADDOP_JREL(c, JUMP_FORWARD, orelse);
1849 n = asdl_seq_LEN(s->v.TryExcept.handlers);
1850 compiler_use_next_block(c, except);
1851 for (i = 0; i < n; i++) {
1852 excepthandler_ty handler = (excepthandler_ty)asdl_seq_GET(
1853 s->v.TryExcept.handlers, i);
1854 if (!handler->v.ExceptHandler.type && i < n-1)
1855 return compiler_error(c, "default 'except:' must be last");
1856 c->u->u_lineno_set = false;
1857 c->u->u_lineno = handler->lineno;
1858 except = compiler_new_block(c);
1859 if (except == NULL)
1860 return 0;
1861 if (handler->v.ExceptHandler.type) {
1862 ADDOP(c, DUP_TOP);
1863 VISIT(c, expr, handler->v.ExceptHandler.type);
1864 ADDOP_I(c, COMPARE_OP, PyCmp_EXC_MATCH);
1865 ADDOP_JABS(c, POP_JUMP_IF_FALSE, except);
1866 }
1867 ADDOP(c, POP_TOP);
1868 if (handler->v.ExceptHandler.name) {
1869 VISIT(c, expr, handler->v.ExceptHandler.name);
1870 }
1871 else {
1872 ADDOP(c, POP_TOP);
1873 }
1874 ADDOP(c, POP_TOP);
1875 VISIT_SEQ(c, stmt, handler->v.ExceptHandler.body);
1876 ADDOP_JREL(c, JUMP_FORWARD, end);
1877 compiler_use_next_block(c, except);
1878 }
1879 ADDOP(c, END_FINALLY);
1880 compiler_use_next_block(c, orelse);
1881 VISIT_SEQ(c, stmt, s->v.TryExcept.orelse);
1882 compiler_use_next_block(c, end);
1883 return 1;
1884 }
1885
1886 static int
1887 compiler_import_as(struct compiler *c, identifier name, identifier asname)
1888 {
1889 /* The IMPORT_NAME opcode was already generated. This function
1890 merely needs to bind the result to a name.
1891
1892 If there is a dot in name, we need to split it and emit a
1893 LOAD_ATTR for each name.
1894 */
1895 const char *src = PyString_AS_STRING(name);
1896 const char *dot = strchr(src, '.');
1897 if (dot) {
1898 /* Consume the base module name to get the first attribute */
1899 src = dot + 1;
1900 while (dot) {
1901 /* NB src is only defined when dot != NULL */
1902 PyObject *attr;
1903 dot = strchr(src, '.');
1904 attr = PyString_FromStringAndSize(src,
1905 dot ? dot - src : strlen(src));
1906 if (!attr)
1907 return -1;
1908 ADDOP_O(c, LOAD_ATTR, attr, names);
1909 Py_DECREF(attr);
1910 src = dot + 1;
1911 }
1912 }
1913 return compiler_nameop(c, asname, Store);
1914 }
1915
1916 static int
1917 compiler_import(struct compiler *c, stmt_ty s)
1918 {
1919 /* The Import node stores a module name like a.b.c as a single
1920 string. This is convenient for all cases except
1921 import a.b.c as d
1922 where we need to parse that string to extract the individual
1923 module names.
1924 XXX Perhaps change the representation to make this case simpler?
1925 */
1926 int i, n = asdl_seq_LEN(s->v.Import.names);
1927
1928 for (i = 0; i < n; i++) {
1929 alias_ty alias = (alias_ty)asdl_seq_GET(s->v.Import.names, i);
1930 int r;
1931 PyObject *level;
1932
1933 if (c->c_flags && (c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT))
1934 level = PyInt_FromLong(0);
1935 else
1936 level = PyInt_FromLong(-1);
1937
1938 if (level == NULL)
1939 return 0;
1940
1941 ADDOP_O(c, LOAD_CONST, level, consts);
1942 Py_DECREF(level);
1943 ADDOP_O(c, LOAD_CONST, Py_None, consts);
1944 ADDOP_NAME(c, IMPORT_NAME, alias->name, names);
1945
1946 if (alias->asname) {
1947 r = compiler_import_as(c, alias->name, alias->asname);
1948 if (!r)
1949 return r;
1950 }
1951 else {
1952 identifier tmp = alias->name;
1953 const char *base = PyString_AS_STRING(alias->name);
1954 char *dot = strchr(base, '.');
1955 if (dot)
1956 tmp = PyString_FromStringAndSize(base,
1957 dot - base);
1958 r = compiler_nameop(c, tmp, Store);
1959 if (dot) {
1960 Py_DECREF(tmp);
1961 }
1962 if (!r)
1963 return r;
1964 }
1965 }
1966 return 1;
1967 }
1968
1969 static int
1970 compiler_from_import(struct compiler *c, stmt_ty s)
1971 {
1972 int i, n = asdl_seq_LEN(s->v.ImportFrom.names);
1973
1974 PyObject *names = PyTuple_New(n);
1975 PyObject *level;
1976 static PyObject *empty_string;
1977
1978 if (!empty_string) {
1979 empty_string = PyString_FromString("");
1980 if (!empty_string)
1981 return 0;
1982 }
1983
1984 if (!names)
1985 return 0;
1986
1987 if (s->v.ImportFrom.level == 0 && c->c_flags &&
1988 !(c->c_flags->cf_flags & CO_FUTURE_ABSOLUTE_IMPORT))
1989 level = PyInt_FromLong(-1);
1990 else
1991 level = PyInt_FromLong(s->v.ImportFrom.level);
1992
1993 if (!level) {
1994 Py_DECREF(names);
1995 return 0;
1996 }
1997
1998 /* build up the names */
1999 for (i = 0; i < n; i++) {
2000 alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i);
2001 Py_INCREF(alias->name);
2002 PyTuple_SET_ITEM(names, i, alias->name);
2003 }
2004
2005 if (s->lineno > c->c_future->ff_lineno && s->v.ImportFrom.module &&
2006 !strcmp(PyString_AS_STRING(s->v.ImportFrom.module), "__future__")) {
2007 Py_DECREF(level);
2008 Py_DECREF(names);
2009 return compiler_error(c, "from __future__ imports must occur "
2010 "at the beginning of the file");
2011 }
2012
2013 ADDOP_O(c, LOAD_CONST, level, consts);
2014 Py_DECREF(level);
2015 ADDOP_O(c, LOAD_CONST, names, consts);
2016 Py_DECREF(names);
2017 if (s->v.ImportFrom.module) {
2018 ADDOP_NAME(c, IMPORT_NAME, s->v.ImportFrom.module, names);
2019 }
2020 else {
2021 ADDOP_NAME(c, IMPORT_NAME, empty_string, names);
2022 }
2023 for (i = 0; i < n; i++) {
2024 alias_ty alias = (alias_ty)asdl_seq_GET(s->v.ImportFrom.names, i);
2025 identifier store_name;
2026
2027 if (i == 0 && *PyString_AS_STRING(alias->name) == '*') {
2028 assert(n == 1);
2029 ADDOP(c, IMPORT_STAR);
2030 return 1;
2031 }
2032
2033 ADDOP_NAME(c, IMPORT_FROM, alias->name, names);
2034 store_name = alias->name;
2035 if (alias->asname)
2036 store_name = alias->asname;
2037
2038 if (!compiler_nameop(c, store_name, Store)) {
2039 Py_DECREF(names);
2040 return 0;
2041 }
2042 }
2043 /* remove imported module */
2044 ADDOP(c, POP_TOP);
2045 return 1;
2046 }
2047
2048 static int
2049 compiler_assert(struct compiler *c, stmt_ty s)
2050 {
2051 static PyObject *assertion_error = NULL;
2052 basicblock *end;
2053
2054 if (Py_OptimizeFlag)
2055 return 1;
2056 if (assertion_error == NULL) {
2057 assertion_error = PyString_InternFromString("AssertionError");
2058 if (assertion_error == NULL)
2059 return 0;
2060 }
2061 if (s->v.Assert.test->kind == Tuple_kind &&
2062 asdl_seq_LEN(s->v.Assert.test->v.Tuple.elts) > 0) {
2063 const char* msg =
2064 "assertion is always true, perhaps remove parentheses?";
2065 if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, c->c_filename,
2066 c->u->u_lineno, NULL, NULL) == -1)
2067 return 0;
2068 }
2069 VISIT(c, expr, s->v.Assert.test);
2070 end = compiler_new_block(c);
2071 if (end == NULL)
2072 return 0;
2073 ADDOP_JABS(c, POP_JUMP_IF_TRUE, end);
2074 ADDOP_O(c, LOAD_GLOBAL, assertion_error, names);
2075 if (s->v.Assert.msg) {
2076 VISIT(c, expr, s->v.Assert.msg);
2077 ADDOP_I(c, RAISE_VARARGS, 2);
2078 }
2079 else {
2080 ADDOP_I(c, RAISE_VARARGS, 1);
2081 }
2082 compiler_use_next_block(c, end);
2083 return 1;
2084 }
2085
2086 static int
2087 compiler_visit_stmt(struct compiler *c, stmt_ty s)
2088 {
2089 int i, n;
2090
2091 /* Always assign a lineno to the next instruction for a stmt. */
2092 c->u->u_lineno = s->lineno;
2093 c->u->u_lineno_set = false;
2094
2095 switch (s->kind) {
2096 case FunctionDef_kind:
2097 return compiler_function(c, s);
2098 case ClassDef_kind:
2099 return compiler_class(c, s);
2100 case Return_kind:
2101 if (c->u->u_ste->ste_type != FunctionBlock)
2102 return compiler_error(c, "'return' outside function");
2103 if (s->v.Return.value) {
2104 VISIT(c, expr, s->v.Return.value);
2105 }
2106 else
2107 ADDOP_O(c, LOAD_CONST, Py_None, consts);
2108 ADDOP(c, RETURN_VALUE);
2109 break;
2110 case Delete_kind:
2111 VISIT_SEQ(c, expr, s->v.Delete.targets)
2112 break;
2113 case Assign_kind:
2114 n = asdl_seq_LEN(s->v.Assign.targets);
2115 VISIT(c, expr, s->v.Assign.value);
2116 for (i = 0; i < n; i++) {
2117 if (i < n - 1)
2118 ADDOP(c, DUP_TOP);
2119 VISIT(c, expr,
2120 (expr_ty)asdl_seq_GET(s->v.Assign.targets, i));
2121 }
2122 break;
2123 case AugAssign_kind:
2124 return compiler_augassign(c, s);
2125 case Print_kind:
2126 return compiler_print(c, s);
2127 case For_kind:
2128 return compiler_for(c, s);
2129 case While_kind:
2130 return compiler_while(c, s);
2131 case If_kind:
2132 return compiler_if(c, s);
2133 case Raise_kind:
2134 n = 0;
2135 if (s->v.Raise.type) {
2136 VISIT(c, expr, s->v.Raise.type);
2137 n++;
2138 if (s->v.Raise.inst) {
2139 VISIT(c, expr, s->v.Raise.inst);
2140 n++;
2141 if (s->v.Raise.tback) {
2142 VISIT(c, expr, s->v.Raise.tback);
2143 n++;
2144 }
2145 }
2146 }
2147 ADDOP_I(c, RAISE_VARARGS, n);
2148 break;
2149 case TryExcept_kind:
2150 return compiler_try_except(c, s);
2151 case TryFinally_kind:
2152 return compiler_try_finally(c, s);
2153 case Assert_kind:
2154 return compiler_assert(c, s);
2155 case Import_kind:
2156 return compiler_import(c, s);
2157 case ImportFrom_kind:
2158 return compiler_from_import(c, s);
2159 case Exec_kind:
2160 VISIT(c, expr, s->v.Exec.body);
2161 if (s->v.Exec.globals) {
2162 VISIT(c, expr, s->v.Exec.globals);
2163 if (s->v.Exec.locals) {
2164 VISIT(c, expr, s->v.Exec.locals);
2165 } else {
2166 ADDOP(c, DUP_TOP);
2167 }
2168 } else {
2169 ADDOP_O(c, LOAD_CONST, Py_None, consts);
2170 ADDOP(c, DUP_TOP);
2171 }
2172 ADDOP(c, EXEC_STMT);
2173 break;
2174 case Global_kind:
2175 break;
2176 case Expr_kind:
2177 if (c->c_interactive && c->c_nestlevel <= 1) {
2178 VISIT(c, expr, s->v.Expr.value);
2179 ADDOP(c, PRINT_EXPR);
2180 }
2181 else if (s->v.Expr.value->kind != Str_kind &&
2182 s->v.Expr.value->kind != Num_kind) {
2183 VISIT(c, expr, s->v.Expr.value);
2184 ADDOP(c, POP_TOP);
2185 }
2186 break;
2187 case Pass_kind:
2188 break;
2189 case Break_kind:
2190 if (!compiler_in_loop(c))
2191 return compiler_error(c, "'break' outside loop");
2192 ADDOP(c, BREAK_LOOP);
2193 break;
2194 case Continue_kind:
2195 return compiler_continue(c);
2196 case With_kind:
2197 return compiler_with(c, s);
2198 }
2199 return 1;
2200 }
2201
2202 static int
2203 unaryop(unaryop_ty op)
2204 {
2205 switch (op) {
2206 case Invert:
2207 return UNARY_INVERT;
2208 case Not:
2209 return UNARY_NOT;
2210 case UAdd:
2211 return UNARY_POSITIVE;
2212 case USub:
2213 return UNARY_NEGATIVE;
2214 default:
2215 PyErr_Format(PyExc_SystemError,
2216 "unary op %d should not be possible", op);
2217 return 0;
2218 }
2219 }
2220
2221 static int
2222 binop(struct compiler *c, operator_ty op)
2223 {
2224 switch (op) {
2225 case Add:
2226 return BINARY_ADD;
2227 case Sub:
2228 return BINARY_SUBTRACT;
2229 case Mult:
2230 return BINARY_MULTIPLY;
2231 case Div:
2232 if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION)
2233 return BINARY_TRUE_DIVIDE;
2234 else
2235 return BINARY_DIVIDE;
2236 case Mod:
2237 return BINARY_MODULO;
2238 case Pow:
2239 return BINARY_POWER;
2240 case LShift:
2241 return BINARY_LSHIFT;
2242 case RShift:
2243 return BINARY_RSHIFT;
2244 case BitOr:
2245 return BINARY_OR;
2246 case BitXor:
2247 return BINARY_XOR;
2248 case BitAnd:
2249 return BINARY_AND;
2250 case FloorDiv:
2251 return BINARY_FLOOR_DIVIDE;
2252 default:
2253 PyErr_Format(PyExc_SystemError,
2254 "binary op %d should not be possible", op);
2255 return 0;
2256 }
2257 }
2258
2259 static int
2260 cmpop(cmpop_ty op)
2261 {
2262 switch (op) {
2263 case Eq:
2264 return PyCmp_EQ;
2265 case NotEq:
2266 return PyCmp_NE;
2267 case Lt:
2268 return PyCmp_LT;
2269 case LtE:
2270 return PyCmp_LE;
2271 case Gt:
2272 return PyCmp_GT;
2273 case GtE:
2274 return PyCmp_GE;
2275 case Is:
2276 return PyCmp_IS;
2277 case IsNot:
2278 return PyCmp_IS_NOT;
2279 case In:
2280 return PyCmp_IN;
2281 case NotIn:
2282 return PyCmp_NOT_IN;
2283 default:
2284 return PyCmp_BAD;
2285 }
2286 }
2287
2288 static int
2289 inplace_binop(struct compiler *c, operator_ty op)
2290 {
2291 switch (op) {
2292 case Add:
2293 return INPLACE_ADD;
2294 case Sub:
2295 return INPLACE_SUBTRACT;
2296 case Mult:
2297 return INPLACE_MULTIPLY;
2298 case Div:
2299 if (c->c_flags && c->c_flags->cf_flags & CO_FUTURE_DIVISION)
2300 return INPLACE_TRUE_DIVIDE;
2301 else
2302 return INPLACE_DIVIDE;
2303 case Mod:
2304 return INPLACE_MODULO;
2305 case Pow:
2306 return INPLACE_POWER;
2307 case LShift:
2308 return INPLACE_LSHIFT;
2309 case RShift:
2310 return INPLACE_RSHIFT;
2311 case BitOr:
2312 return INPLACE_OR;
2313 case BitXor:
2314 return INPLACE_XOR;
2315 case BitAnd:
2316 return INPLACE_AND;
2317 case FloorDiv:
2318 return INPLACE_FLOOR_DIVIDE;
2319 default:
2320 PyErr_Format(PyExc_SystemError,
2321 "inplace binary op %d should not be possible", op);
2322 return 0;
2323 }
2324 }
2325
2326 static int
2327 compiler_nameop(struct compiler *c, identifier name, expr_context_ty ctx)
2328 {
2329 int op, scope, arg;
2330 enum { OP_FAST, OP_GLOBAL, OP_DEREF, OP_NAME } optype;
2331
2332 PyObject *dict = c->u->u_names;
2333 PyObject *mangled;
2334 /* XXX AugStore isn't used anywhere! */
2335
2336 mangled = _Py_Mangle(c->u->u_private, name);
2337 if (!mangled)
2338 return 0;
2339
2340 op = 0;
2341 optype = OP_NAME;
2342 scope = PyST_GetScope(c->u->u_ste, mangled);
2343 switch (scope) {
2344 case FREE:
2345 dict = c->u->u_freevars;
2346 optype = OP_DEREF;
2347 break;
2348 case CELL:
2349 dict = c->u->u_cellvars;
2350 optype = OP_DEREF;
2351 break;
2352 case LOCAL:
2353 if (c->u->u_ste->ste_type == FunctionBlock)
2354 optype = OP_FAST;
2355 break;
2356 case GLOBAL_IMPLICIT:
2357 if (c->u->u_ste->ste_type == FunctionBlock &&
2358 !c->u->u_ste->ste_unoptimized)
2359 optype = OP_GLOBAL;
2360 break;
2361 case GLOBAL_EXPLICIT:
2362 optype = OP_GLOBAL;
2363 break;
2364 default:
2365 /* scope can be 0 */
2366 break;
2367 }
2368
2369 /* XXX Leave assert here, but handle __doc__ and the like better */
2370 assert(scope || PyString_AS_STRING(name)[0] == '_');
2371
2372 switch (optype) {
2373 case OP_DEREF:
2374 switch (ctx) {
2375 case Load: op = LOAD_DEREF; break;
2376 case Store: op = STORE_DEREF; break;
2377 case AugLoad:
2378 case AugStore:
2379 break;
2380 case Del:
2381 PyErr_Format(PyExc_SyntaxError,
2382 "can not delete variable '%s' referenced "
2383 "in nested scope",
2384 PyString_AS_STRING(name));
2385 Py_DECREF(mangled);
2386 return 0;
2387 case Param:
2388 default:
2389 PyErr_SetString(PyExc_SystemError,
2390 "param invalid for deref variable");
2391 return 0;
2392 }
2393 break;
2394 case OP_FAST:
2395 switch (ctx) {
2396 case Load: op = LOAD_FAST; break;
2397 case Store: op = STORE_FAST; break;
2398 case Del: op = DELETE_FAST; break;
2399 case AugLoad:
2400 case AugStore:
2401 break;
2402 case Param:
2403 default:
2404 PyErr_SetString(PyExc_SystemError,
2405 "param invalid for local variable");
2406 return 0;
2407 }
2408 ADDOP_O(c, op, mangled, varnames);
2409 Py_DECREF(mangled);
2410 return 1;
2411 case OP_GLOBAL:
2412 switch (ctx) {
2413 case Load: op = LOAD_GLOBAL; break;
2414 case Store: op = STORE_GLOBAL; break;
2415 case Del: op = DELETE_GLOBAL; break;
2416 case AugLoad:
2417 case AugStore:
2418 break;
2419 case Param:
2420 default:
2421 PyErr_SetString(PyExc_SystemError,
2422 "param invalid for global variable");
2423 return 0;
2424 }
2425 break;
2426 case OP_NAME:
2427 switch (ctx) {
2428 case Load: op = LOAD_NAME; break;
2429 case Store: op = STORE_NAME; break;
2430 case Del: op = DELETE_NAME; break;
2431 case AugLoad:
2432 case AugStore:
2433 break;
2434 case Param:
2435 default:
2436 PyErr_SetString(PyExc_SystemError,
2437 "param invalid for name variable");
2438 return 0;
2439 }
2440 break;
2441 }
2442
2443 assert(op);
2444 arg = compiler_add_o(c, dict, mangled);
2445 Py_DECREF(mangled);
2446 if (arg < 0)
2447 return 0;
2448 return compiler_addop_i(c, op, arg);
2449 }
2450
2451 static int
2452 compiler_boolop(struct compiler *c, expr_ty e)
2453 {
2454 basicblock *end;
2455 int jumpi, i, n;
2456 asdl_seq *s;
2457
2458 assert(e->kind == BoolOp_kind);
2459 if (e->v.BoolOp.op == And)
2460 jumpi = JUMP_IF_FALSE_OR_POP;
2461 else
2462 jumpi = JUMP_IF_TRUE_OR_POP;
2463 end = compiler_new_block(c);
2464 if (end == NULL)
2465 return 0;
2466 s = e->v.BoolOp.values;
2467 n = asdl_seq_LEN(s) - 1;
2468 assert(n >= 0);
2469 for (i = 0; i < n; ++i) {
2470 VISIT(c, expr, (expr_ty)asdl_seq_GET(s, i));
2471 ADDOP_JABS(c, jumpi, end);
2472 }
2473 VISIT(c, expr, (expr_ty)asdl_seq_GET(s, n));
2474 compiler_use_next_block(c, end);
2475 return 1;
2476 }
2477
2478 static int
2479 compiler_list(struct compiler *c, expr_ty e)
2480 {
2481 int n = asdl_seq_LEN(e->v.List.elts);
2482 if (e->v.List.ctx == Store) {
2483 ADDOP_I(c, UNPACK_SEQUENCE, n);
2484 }
2485 VISIT_SEQ(c, expr, e->v.List.elts);
2486 if (e->v.List.ctx == Load) {
2487 ADDOP_I(c, BUILD_LIST, n);
2488 }
2489 return 1;
2490 }
2491
2492 static int
2493 compiler_tuple(struct compiler *c, expr_ty e)
2494 {
2495 int n = asdl_seq_LEN(e->v.Tuple.elts);
2496 if (e->v.Tuple.ctx == Store) {
2497 ADDOP_I(c, UNPACK_SEQUENCE, n);
2498 }
2499 VISIT_SEQ(c, expr, e->v.Tuple.elts);
2500 if (e->v.Tuple.ctx == Load) {
2501 ADDOP_I(c, BUILD_TUPLE, n);
2502 }
2503 return 1;
2504 }
2505
2506 static int
2507 compiler_compare(struct compiler *c, expr_ty e)
2508 {
2509 int i, n;
2510 basicblock *cleanup = NULL;
2511
2512 /* XXX the logic can be cleaned up for 1 or multiple comparisons */
2513 VISIT(c, expr, e->v.Compare.left);
2514 n = asdl_seq_LEN(e->v.Compare.ops);
2515 assert(n > 0);
2516 if (n > 1) {
2517 cleanup = compiler_new_block(c);
2518 if (cleanup == NULL)
2519 return 0;
2520 VISIT(c, expr,
2521 (expr_ty)asdl_seq_GET(e->v.Compare.comparators, 0));
2522 }
2523 for (i = 1; i < n; i++) {
2524 ADDOP(c, DUP_TOP);
2525 ADDOP(c, ROT_THREE);
2526 ADDOP_I(c, COMPARE_OP,
2527 cmpop((cmpop_ty)(asdl_seq_GET(
2528 e->v.Compare.ops, i - 1))));
2529 ADDOP_JABS(c, JUMP_IF_FALSE_OR_POP, cleanup);
2530 NEXT_BLOCK(c);
2531 if (i < (n - 1))
2532 VISIT(c, expr,
2533 (expr_ty)asdl_seq_GET(e->v.Compare.comparators, i));
2534 }
2535 VISIT(c, expr, (expr_ty)asdl_seq_GET(e->v.Compare.comparators, n - 1));
2536 ADDOP_I(c, COMPARE_OP,
2537 cmpop((cmpop_ty)(asdl_seq_GET(e->v.Compare.ops, n - 1))));
2538 if (n > 1) {
2539 basicblock *end = compiler_new_block(c);
2540 if (end == NULL)
2541 return 0;
2542 ADDOP_JREL(c, JUMP_FORWARD, end);
2543 compiler_use_next_block(c, cleanup);
2544 ADDOP(c, ROT_TWO);
2545 ADDOP(c, POP_TOP);
2546 compiler_use_next_block(c, end);
2547 }
2548 return 1;
2549 }
2550
2551 static int
2552 compiler_call(struct compiler *c, expr_ty e)
2553 {
2554 int n, code = 0;
2555
2556 VISIT(c, expr, e->v.Call.func);
2557 n = asdl_seq_LEN(e->v.Call.args);
2558 VISIT_SEQ(c, expr, e->v.Call.args);
2559 if (e->v.Call.keywords) {
2560 VISIT_SEQ(c, keyword, e->v.Call.keywords);
2561 n |= asdl_seq_LEN(e->v.Call.keywords) << 8;
2562 }
2563 if (e->v.Call.starargs) {
2564 VISIT(c, expr, e->v.Call.starargs);
2565 code |= 1;
2566 }
2567 if (e->v.Call.kwargs) {
2568 VISIT(c, expr, e->v.Call.kwargs);
2569 code |= 2;
2570 }
2571 switch (code) {
2572 case 0:
2573 ADDOP_I(c, CALL_FUNCTION, n);
2574 break;
2575 case 1:
2576 ADDOP_I(c, CALL_FUNCTION_VAR, n);
2577 break;
2578 case 2:
2579 ADDOP_I(c, CALL_FUNCTION_KW, n);
2580 break;
2581 case 3:
2582 ADDOP_I(c, CALL_FUNCTION_VAR_KW, n);
2583 break;
2584 }
2585 return 1;
2586 }
2587
2588 static int
2589 compiler_listcomp_generator(struct compiler *c, asdl_seq *generators,
2590 int gen_index, expr_ty elt)
2591 {
2592 /* generate code for the iterator, then each of the ifs,
2593 and then write to the element */
2594
2595 comprehension_ty l;
2596 basicblock *start, *anchor, *skip, *if_cleanup;
2597 int i, n;
2598
2599 start = compiler_new_block(c);
2600 skip = compiler_new_block(c);
2601 if_cleanup = compiler_new_block(c);
2602 anchor = compiler_new_block(c);
2603
2604 if (start == NULL || skip == NULL || if_cleanup == NULL ||
2605 anchor == NULL)
2606 return 0;
2607
2608 l = (comprehension_ty)asdl_seq_GET(generators, gen_index);
2609 VISIT(c, expr, l->iter);
2610 ADDOP(c, GET_ITER);
2611 compiler_use_next_block(c, start);
2612 ADDOP_JREL(c, FOR_ITER, anchor);
2613 NEXT_BLOCK(c);
2614 VISIT(c, expr, l->target);
2615
2616 /* XXX this needs to be cleaned up...a lot! */
2617 n = asdl_seq_LEN(l->ifs);
2618 for (i = 0; i < n; i++) {
2619 expr_ty e = (expr_ty)asdl_seq_GET(l->ifs, i);
2620 VISIT(c, expr, e);
2621 ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup);
2622 NEXT_BLOCK(c);
2623 }
2624
2625 if (++gen_index < asdl_seq_LEN(generators))
2626 if (!compiler_listcomp_generator(c, generators, gen_index, elt))
2627 return 0;
2628
2629 /* only append after the last for generator */
2630 if (gen_index >= asdl_seq_LEN(generators)) {
2631 VISIT(c, expr, elt);
2632 ADDOP_I(c, LIST_APPEND, gen_index+1);
2633
2634 compiler_use_next_block(c, skip);
2635 }
2636 compiler_use_next_block(c, if_cleanup);
2637 ADDOP_JABS(c, JUMP_ABSOLUTE, start);
2638 compiler_use_next_block(c, anchor);
2639
2640 return 1;
2641 }
2642
2643 static int
2644 compiler_listcomp(struct compiler *c, expr_ty e)
2645 {
2646 assert(e->kind == ListComp_kind);
2647 ADDOP_I(c, BUILD_LIST, 0);
2648 return compiler_listcomp_generator(c, e->v.ListComp.generators, 0,
2649 e->v.ListComp.elt);
2650 }
2651
2652 static int
2653 compiler_genexp_generator(struct compiler *c,
2654 asdl_seq *generators, int gen_index,
2655 expr_ty elt)
2656 {
2657 /* generate code for the iterator, then each of the ifs,
2658 and then write to the element */
2659
2660 comprehension_ty ge;
2661 basicblock *start, *anchor, *skip, *if_cleanup, *end;
2662 int i, n;
2663
2664 start = compiler_new_block(c);
2665 skip = compiler_new_block(c);
2666 if_cleanup = compiler_new_block(c);
2667 anchor = compiler_new_block(c);
2668 end = compiler_new_block(c);
2669
2670 if (start == NULL || skip == NULL || if_cleanup == NULL ||
2671 anchor == NULL || end == NULL)
2672 return 0;
2673
2674 ge = (comprehension_ty)asdl_seq_GET(generators, gen_index);
2675 ADDOP_JREL(c, SETUP_LOOP, end);
2676 if (!compiler_push_fblock(c, LOOP, start))
2677 return 0;
2678
2679 if (gen_index == 0) {
2680 /* Receive outermost iter as an implicit argument */
2681 c->u->u_argcount = 1;
2682 ADDOP_I(c, LOAD_FAST, 0);
2683 }
2684 else {
2685 /* Sub-iter - calculate on the fly */
2686 VISIT(c, expr, ge->iter);
2687 ADDOP(c, GET_ITER);
2688 }
2689 compiler_use_next_block(c, start);
2690 ADDOP_JREL(c, FOR_ITER, anchor);
2691 NEXT_BLOCK(c);
2692 VISIT(c, expr, ge->target);
2693
2694 /* XXX this needs to be cleaned up...a lot! */
2695 n = asdl_seq_LEN(ge->ifs);
2696 for (i = 0; i < n; i++) {
2697 expr_ty e = (expr_ty)asdl_seq_GET(ge->ifs, i);
2698 VISIT(c, expr, e);
2699 ADDOP_JABS(c, POP_JUMP_IF_FALSE, if_cleanup);
2700 NEXT_BLOCK(c);
2701 }
2702
2703 if (++gen_index < asdl_seq_LEN(generators))
2704 if (!compiler_genexp_generator(c, generators, gen_index, elt))
2705 return 0;
2706
2707 /* only append after the last 'for' generator */
2708 if (gen_index >= asdl_seq_LEN(generators)) {
2709 VISIT(c, expr, elt);
2710 ADDOP(c, YIELD_VALUE);
2711 ADDOP(c, POP_TOP);
2712
2713 compiler_use_next_block(c, skip);
2714 }
2715 compiler_use_next_block(c, if_cleanup);
2716 ADDOP_JABS(c, JUMP_ABSOLUTE, start);
2717 compiler_use_next_block(c, anchor);
2718 ADDOP(c, POP_BLOCK);
2719 compiler_pop_fblock(c, LOOP, start);
2720 compiler_use_next_block(c, end);
2721
2722 return 1;
2723 }
2724
2725 static int
2726 compiler_genexp(struct compiler *c, expr_ty e)
2727 {
2728 static identifier name;
2729 PyCodeObject *co;
2730 expr_ty outermost_iter = ((comprehension_ty)
2731 (asdl_seq_GET(e->v.GeneratorExp.generators,
2732 0)))->iter;
2733
2734 if (!name) {
2735 name = PyString_FromString("<genexpr>");
2736 if (!name)
2737 return 0;
2738 }
2739
2740 if (!compiler_enter_scope(c, name, (void *)e, e->lineno))
2741 return 0;
2742 compiler_genexp_generator(c, e->v.GeneratorExp.generators, 0,
2743 e->v.GeneratorExp.elt);
2744 co = assemble(c, 1);
2745 compiler_exit_scope(c);
2746 if (co == NULL)
2747 return 0;
2748
2749 compiler_make_closure(c, co, 0);
2750 Py_DECREF(co);
2751
2752 VISIT(c, expr, outermost_iter);
2753 ADDOP(c, GET_ITER);
2754 ADDOP_I(c, CALL_FUNCTION, 1);
2755
2756 return 1;
2757 }
2758
2759 static int
2760 compiler_visit_keyword(struct compiler *c, keyword_ty k)
2761 {
2762 ADDOP_O(c, LOAD_CONST, k->arg, consts);
2763 VISIT(c, expr, k->value);
2764 return 1;
2765 }
2766
2767 /* Test whether expression is constant. For constants, report
2768 whether they are true or false.
2769
2770 Return values: 1 for true, 0 for false, -1 for non-constant.
2771 */
2772
2773 static int
2774 expr_constant(expr_ty e)
2775 {
2776 switch (e->kind) {
2777 case Num_kind:
2778 return PyObject_IsTrue(e->v.Num.n);
2779 case Str_kind:
2780 return PyObject_IsTrue(e->v.Str.s);
2781 case Name_kind:
2782 /* __debug__ is not assignable, so we can optimize
2783 * it away in if and while statements */
2784 if (strcmp(PyString_AS_STRING(e->v.Name.id),
2785 "__debug__") == 0)
2786 return ! Py_OptimizeFlag;
2787 /* fall through */
2788 default:
2789 return -1;
2790 }
2791 }
2792
2793 /*
2794 Implements the with statement from PEP 343.
2795
2796 The semantics outlined in that PEP are as follows:
2797
2798 with EXPR as VAR:
2799 BLOCK
2800
2801 It is implemented roughly as:
2802
2803 context = EXPR
2804 exit = context.__exit__ # not calling it
2805 value = context.__enter__()
2806 try:
2807 VAR = value # if VAR present in the syntax
2808 BLOCK
2809 finally:
2810 if an exception was raised:
2811 exc = copy of (exception, instance, traceback)
2812 else:
2813 exc = (None, None, None)
2814 exit(*exc)
2815 */
2816 static int
2817 compiler_with(struct compiler *c, stmt_ty s)
2818 {
2819 basicblock *block, *finally;
2820
2821 assert(s->kind == With_kind);
2822
2823 block = compiler_new_block(c);
2824 finally = compiler_new_block(c);
2825 if (!block || !finally)
2826 return 0;
2827
2828 /* Evaluate EXPR */
2829 VISIT(c, expr, s->v.With.context_expr);
2830 ADDOP_JREL(c, SETUP_WITH, finally);
2831
2832 /* SETUP_WITH pushes a finally block. */
2833 compiler_use_next_block(c, block);
2834 if (!compiler_push_fblock(c, FINALLY_TRY, block)) {
2835 return 0;
2836 }
2837
2838 if (s->v.With.optional_vars) {
2839 VISIT(c, expr, s->v.With.optional_vars);
2840 }
2841 else {
2842 /* Discard result from context.__enter__() */
2843 ADDOP(c, POP_TOP);
2844 }
2845
2846 /* BLOCK code */
2847 VISIT_SEQ(c, stmt, s->v.With.body);
2848
2849 /* End of try block; start the finally block */
2850 ADDOP(c, POP_BLOCK);
2851 compiler_pop_fblock(c, FINALLY_TRY, block);
2852
2853 ADDOP_O(c, LOAD_CONST, Py_None, consts);
2854 compiler_use_next_block(c, finally);
2855 if (!compiler_push_fblock(c, FINALLY_END, finally))
2856 return 0;
2857
2858 /* Finally block starts; context.__exit__ is on the stack under
2859 the exception or return information. Just issue our magic
2860 opcode. */
2861 ADDOP(c, WITH_CLEANUP);
2862
2863 /* Finally block ends. */
2864 ADDOP(c, END_FINALLY);
2865 compiler_pop_fblock(c, FINALLY_END, finally);
2866 return 1;
2867 }
2868
2869 static int
2870 compiler_visit_expr(struct compiler *c, expr_ty e)
2871 {
2872 int i, n;
2873
2874 /* If expr e has a different line number than the last expr/stmt,
2875 set a new line number for the next instruction.
2876 */
2877 if (e->lineno > c->u->u_lineno) {
2878 c->u->u_lineno = e->lineno;
2879 c->u->u_lineno_set = false;
2880 }
2881 switch (e->kind) {
2882 case BoolOp_kind:
2883 return compiler_boolop(c, e);
2884 case BinOp_kind:
2885 VISIT(c, expr, e->v.BinOp.left);
2886 VISIT(c, expr, e->v.BinOp.right);
2887 ADDOP(c, binop(c, e->v.BinOp.op));
2888 break;
2889 case UnaryOp_kind:
2890 VISIT(c, expr, e->v.UnaryOp.operand);
2891 ADDOP(c, unaryop(e->v.UnaryOp.op));
2892 break;
2893 case Lambda_kind:
2894 return compiler_lambda(c, e);
2895 case IfExp_kind:
2896 return compiler_ifexp(c, e);
2897 case Dict_kind:
2898 n = asdl_seq_LEN(e->v.Dict.values);
2899 ADDOP_I(c, BUILD_MAP, (n>0xFFFF ? 0xFFFF : n));
2900 for (i = 0; i < n; i++) {
2901 VISIT(c, expr,
2902 (expr_ty)asdl_seq_GET(e->v.Dict.values, i));
2903 VISIT(c, expr,
2904 (expr_ty)asdl_seq_GET(e->v.Dict.keys, i));
2905 ADDOP(c, STORE_MAP);
2906 }
2907 break;
2908 case ListComp_kind:
2909 return compiler_listcomp(c, e);
2910 case GeneratorExp_kind:
2911 return compiler_genexp(c, e);
2912 case Yield_kind:
2913 if (c->u->u_ste->ste_type != FunctionBlock)
2914 return compiler_error(c, "'yield' outside function");
2915 if (e->v.Yield.value) {
2916 VISIT(c, expr, e->v.Yield.value);
2917 }
2918 else {
2919 ADDOP_O(c, LOAD_CONST, Py_None, consts);
2920 }
2921 ADDOP(c, YIELD_VALUE);
2922 break;
2923 case Compare_kind:
2924 return compiler_compare(c, e);
2925 case Call_kind:
2926 return compiler_call(c, e);
2927 case Repr_kind:
2928 VISIT(c, expr, e->v.Repr.value);
2929 ADDOP(c, UNARY_CONVERT);
2930 break;
2931 case Num_kind:
2932 ADDOP_O(c, LOAD_CONST, e->v.Num.n, consts);
2933 break;
2934 case Str_kind:
2935 ADDOP_O(c, LOAD_CONST, e->v.Str.s, consts);
2936 break;
2937 /* The following exprs can be assignment targets. */
2938 case Attribute_kind:
2939 if (e->v.Attribute.ctx != AugStore)
2940 VISIT(c, expr, e->v.Attribute.value);
2941 switch (e->v.Attribute.ctx) {
2942 case AugLoad:
2943 ADDOP(c, DUP_TOP);
2944 /* Fall through to load */
2945 case Load:
2946 ADDOP_NAME(c, LOAD_ATTR, e->v.Attribute.attr, names);
2947 break;
2948 case AugStore:
2949 ADDOP(c, ROT_TWO);
2950 /* Fall through to save */
2951 case Store:
2952 ADDOP_NAME(c, STORE_ATTR, e->v.Attribute.attr, names);
2953 break;
2954 case Del:
2955 ADDOP_NAME(c, DELETE_ATTR, e->v.Attribute.attr, names);
2956 break;
2957 case Param:
2958 default:
2959 PyErr_SetString(PyExc_SystemError,
2960 "param invalid in attribute expression");
2961 return 0;
2962 }
2963 break;
2964 case Subscript_kind:
2965 switch (e->v.Subscript.ctx) {
2966 case AugLoad:
2967 VISIT(c, expr, e->v.Subscript.value);
2968 VISIT_SLICE(c, e->v.Subscript.slice, AugLoad);
2969 break;
2970 case Load:
2971 VISIT(c, expr, e->v.Subscript.value);
2972 VISIT_SLICE(c, e->v.Subscript.slice, Load);
2973 break;
2974 case AugStore:
2975 VISIT_SLICE(c, e->v.Subscript.slice, AugStore);
2976 break;
2977 case Store:
2978 VISIT(c, expr, e->v.Subscript.value);
2979 VISIT_SLICE(c, e->v.Subscript.slice, Store);
2980 break;
2981 case Del:
2982 VISIT(c, expr, e->v.Subscript.value);
2983 VISIT_SLICE(c, e->v.Subscript.slice, Del);
2984 break;
2985 case Param:
2986 default:
2987 PyErr_SetString(PyExc_SystemError,
2988 "param invalid in subscript expression");
2989 return 0;
2990 }
2991 break;
2992 case Name_kind:
2993 return compiler_nameop(c, e->v.Name.id, e->v.Name.ctx);
2994 /* child nodes of List and Tuple will have expr_context set */
2995 case List_kind:
2996 return compiler_list(c, e);
2997 case Tuple_kind:
2998 return compiler_tuple(c, e);
2999 }
3000 return 1;
3001 }
3002
3003 static int
3004 compiler_augassign(struct compiler *c, stmt_ty s)
3005 {
3006 expr_ty e = s->v.AugAssign.target;
3007 expr_ty auge;
3008
3009 assert(s->kind == AugAssign_kind);
3010
3011 switch (e->kind) {
3012 case Attribute_kind:
3013 auge = Attribute(e->v.Attribute.value, e->v.Attribute.attr,
3014 AugLoad, e->lineno, e->col_offset, c->c_arena);
3015 if (auge == NULL)
3016 return 0;
3017 VISIT(c, expr, auge);
3018 VISIT(c, expr, s->v.AugAssign.value);
3019 ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
3020 auge->v.Attribute.ctx = AugStore;
3021 VISIT(c, expr, auge);
3022 break;
3023 case Subscript_kind:
3024 auge = Subscript(e->v.Subscript.value, e->v.Subscript.slice,
3025 AugLoad, e->lineno, e->col_offset, c->c_arena);
3026 if (auge == NULL)
3027 return 0;
3028 VISIT(c, expr, auge);
3029 VISIT(c, expr, s->v.AugAssign.value);
3030 ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
3031 auge->v.Subscript.ctx = AugStore;
3032 VISIT(c, expr, auge);
3033 break;
3034 case Name_kind:
3035 if (!compiler_nameop(c, e->v.Name.id, Load))
3036 return 0;
3037 VISIT(c, expr, s->v.AugAssign.value);
3038 ADDOP(c, inplace_binop(c, s->v.AugAssign.op));
3039 return compiler_nameop(c, e->v.Name.id, Store);
3040 default:
3041 PyErr_Format(PyExc_SystemError,
3042 "invalid node type (%d) for augmented assignment",
3043 e->kind);
3044 return 0;
3045 }
3046 return 1;
3047 }
3048
3049 static int
3050 compiler_push_fblock(struct compiler *c, enum fblocktype t, basicblock *b)
3051 {
3052 struct fblockinfo *f;
3053 if (c->u->u_nfblocks >= CO_MAXBLOCKS) {
3054 PyErr_SetString(PyExc_SystemError,
3055 "too many statically nested blocks");
3056 return 0;
3057 }
3058 f = &c->u->u_fblock[c->u->u_nfblocks++];
3059 f->fb_type = t;
3060 f->fb_block = b;
3061 return 1;
3062 }
3063
3064 static void
3065 compiler_pop_fblock(struct compiler *c, enum fblocktype t, basicblock *b)
3066 {
3067 struct compiler_unit *u = c->u;
3068 assert(u->u_nfblocks > 0);
3069 u->u_nfblocks--;
3070 assert(u->u_fblock[u->u_nfblocks].fb_type == t);
3071 assert(u->u_fblock[u->u_nfblocks].fb_block == b);
3072 }
3073
3074 static int
3075 compiler_in_loop(struct compiler *c) {
3076 int i;
3077 struct compiler_unit *u = c->u;
3078 for (i = 0; i < u->u_nfblocks; ++i) {
3079 if (u->u_fblock[i].fb_type == LOOP)
3080 return 1;
3081 }
3082 return 0;
3083 }
3084 /* Raises a SyntaxError and returns 0.
3085 If something goes wrong, a different exception may be raised.
3086 */
3087
3088 static int
3089 compiler_error(struct compiler *c, const char *errstr)
3090 {
3091 PyObject *loc;
3092 PyObject *u = NULL, *v = NULL;
3093
3094 loc = PyErr_ProgramText(c->c_filename, c->u->u_lineno);
3095 if (!loc) {
3096 Py_INCREF(Py_None);
3097 loc = Py_None;
3098 }
3099 u = Py_BuildValue("(ziOO)", c->c_filename, c->u->u_lineno,
3100 Py_None, loc);
3101 if (!u)
3102 goto exit;
3103 v = Py_BuildValue("(zO)", errstr, u);
3104 if (!v)
3105 goto exit;
3106 PyErr_SetObject(PyExc_SyntaxError, v);
3107 exit:
3108 Py_DECREF(loc);
3109 Py_XDECREF(u);
3110 Py_XDECREF(v);
3111 return 0;
3112 }
3113
3114 static int
3115 compiler_handle_subscr(struct compiler *c, const char *kind,
3116 expr_context_ty ctx)
3117 {
3118 int op = 0;
3119
3120 /* XXX this code is duplicated */
3121 switch (ctx) {
3122 case AugLoad: /* fall through to Load */
3123 case Load: op = BINARY_SUBSCR; break;
3124 case AugStore:/* fall through to Store */
3125 case Store: op = STORE_SUBSCR; break;
3126 case Del: op = DELETE_SUBSCR; break;
3127 case Param:
3128 PyErr_Format(PyExc_SystemError,
3129 "invalid %s kind %d in subscript\n",
3130 kind, ctx);
3131 return 0;
3132 }
3133 if (ctx == AugLoad) {
3134 ADDOP_I(c, DUP_TOPX, 2);
3135 }
3136 else if (ctx == AugStore) {
3137 ADDOP(c, ROT_THREE);
3138 }
3139 ADDOP(c, op);
3140 return 1;
3141 }
3142
3143 static int
3144 compiler_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
3145 {
3146 int n = 2;
3147 assert(s->kind == Slice_kind);
3148
3149 /* only handles the cases where BUILD_SLICE is emitted */
3150 if (s->v.Slice.lower) {
3151 VISIT(c, expr, s->v.Slice.lower);
3152 }
3153 else {
3154 ADDOP_O(c, LOAD_CONST, Py_None, consts);
3155 }
3156
3157 if (s->v.Slice.upper) {
3158 VISIT(c, expr, s->v.Slice.upper);
3159 }
3160 else {
3161 ADDOP_O(c, LOAD_CONST, Py_None, consts);
3162 }
3163
3164 if (s->v.Slice.step) {
3165 n++;
3166 VISIT(c, expr, s->v.Slice.step);
3167 }
3168 ADDOP_I(c, BUILD_SLICE, n);
3169 return 1;
3170 }
3171
3172 static int
3173 compiler_simple_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
3174 {
3175 int op = 0, slice_offset = 0, stack_count = 0;
3176
3177 assert(s->v.Slice.step == NULL);
3178 if (s->v.Slice.lower) {
3179 slice_offset++;
3180 stack_count++;
3181 if (ctx != AugStore)
3182 VISIT(c, expr, s->v.Slice.lower);
3183 }
3184 if (s->v.Slice.upper) {
3185 slice_offset += 2;
3186 stack_count++;
3187 if (ctx != AugStore)
3188 VISIT(c, expr, s->v.Slice.upper);
3189 }
3190
3191 if (ctx == AugLoad) {
3192 switch (stack_count) {
3193 case 0: ADDOP(c, DUP_TOP); break;
3194 case 1: ADDOP_I(c, DUP_TOPX, 2); break;
3195 case 2: ADDOP_I(c, DUP_TOPX, 3); break;
3196 }
3197 }
3198 else if (ctx == AugStore) {
3199 switch (stack_count) {
3200 case 0: ADDOP(c, ROT_TWO); break;
3201 case 1: ADDOP(c, ROT_THREE); break;
3202 case 2: ADDOP(c, ROT_FOUR); break;
3203 }
3204 }
3205
3206 switch (ctx) {
3207 case AugLoad: /* fall through to Load */
3208 case Load: op = SLICE; break;
3209 case AugStore:/* fall through to Store */
3210 case Store: op = STORE_SLICE; break;
3211 case Del: op = DELETE_SLICE; break;
3212 case Param:
3213 default:
3214 PyErr_SetString(PyExc_SystemError,
3215 "param invalid in simple slice");
3216 return 0;
3217 }
3218
3219 ADDOP(c, op + slice_offset);
3220 return 1;
3221 }
3222
3223 static int
3224 compiler_visit_nested_slice(struct compiler *c, slice_ty s,
3225 expr_context_ty ctx)
3226 {
3227 switch (s->kind) {
3228 case Ellipsis_kind:
3229 ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts);
3230 break;
3231 case Slice_kind:
3232 return compiler_slice(c, s, ctx);
3233 case Index_kind:
3234 VISIT(c, expr, s->v.Index.value);
3235 break;
3236 case ExtSlice_kind:
3237 default:
3238 PyErr_SetString(PyExc_SystemError,
3239 "extended slice invalid in nested slice");
3240 return 0;
3241 }
3242 return 1;
3243 }
3244
3245 static int
3246 compiler_visit_slice(struct compiler *c, slice_ty s, expr_context_ty ctx)
3247 {
3248 char * kindname = NULL;
3249 switch (s->kind) {
3250 case Index_kind:
3251 kindname = "index";
3252 if (ctx != AugStore) {
3253 VISIT(c, expr, s->v.Index.value);
3254 }
3255 break;
3256 case Ellipsis_kind:
3257 kindname = "ellipsis";
3258 if (ctx != AugStore) {
3259 ADDOP_O(c, LOAD_CONST, Py_Ellipsis, consts);
3260 }
3261 break;
3262 case Slice_kind:
3263 kindname = "slice";
3264 if (!s->v.Slice.step)
3265 return compiler_simple_slice(c, s, ctx);
3266 if (ctx != AugStore) {
3267 if (!compiler_slice(c, s, ctx))
3268 return 0;
3269 }
3270 break;
3271 case ExtSlice_kind:
3272 kindname = "extended slice";
3273 if (ctx != AugStore) {
3274 int i, n = asdl_seq_LEN(s->v.ExtSlice.dims);
3275 for (i = 0; i < n; i++) {
3276 slice_ty sub = (slice_ty)asdl_seq_GET(
3277 s->v.ExtSlice.dims, i);
3278 if (!compiler_visit_nested_slice(c, sub, ctx))
3279 return 0;
3280 }
3281 ADDOP_I(c, BUILD_TUPLE, n);
3282 }
3283 break;
3284 default:
3285 PyErr_Format(PyExc_SystemError,
3286 "invalid subscript kind %d", s->kind);
3287 return 0;
3288 }
3289 return compiler_handle_subscr(c, kindname, ctx);
3290 }
3291
3292
3293 /* End of the compiler section, beginning of the assembler section */
3294
3295 /* do depth-first search of basic block graph, starting with block.
3296 post records the block indices in post-order.
3297
3298 XXX must handle implicit jumps from one block to next
3299 */
3300
3301 struct assembler {
3302 PyObject *a_bytecode; /* string containing bytecode */
3303 int a_offset; /* offset into bytecode */
3304 int a_nblocks; /* number of reachable blocks */
3305 basicblock **a_postorder; /* list of blocks in dfs postorder */
3306 PyObject *a_lnotab; /* string containing lnotab */
3307 int a_lnotab_off; /* offset into lnotab */
3308 int a_lineno; /* last lineno of emitted instruction */
3309 int a_lineno_off; /* bytecode offset of last lineno */
3310 };
3311
3312 static void
3313 dfs(struct compiler *c, basicblock *b, struct assembler *a)
3314 {
3315 int i;
3316 struct instr *instr = NULL;
3317
3318 if (b->b_seen)
3319 return;
3320 b->b_seen = 1;
3321 if (b->b_next != NULL)
3322 dfs(c, b->b_next, a);
3323 for (i = 0; i < b->b_iused; i++) {
3324 instr = &b->b_instr[i];
3325 if (instr->i_jrel || instr->i_jabs)
3326 dfs(c, instr->i_target, a);
3327 }
3328 a->a_postorder[a->a_nblocks++] = b;
3329 }
3330
3331 static int
3332 stackdepth_walk(struct compiler *c, basicblock *b, int depth, int maxdepth)
3333 {
3334 int i, target_depth;
3335 struct instr *instr;
3336 if (b->b_seen || b->b_startdepth >= depth)
3337 return maxdepth;
3338 b->b_seen = 1;
3339 b->b_startdepth = depth;
3340 for (i = 0; i < b->b_iused; i++) {
3341 instr = &b->b_instr[i];
3342 depth += opcode_stack_effect(instr->i_opcode, instr->i_oparg);
3343 if (depth > maxdepth)
3344 maxdepth = depth;
3345 assert(depth >= 0); /* invalid code or bug in stackdepth() */
3346 if (instr->i_jrel || instr->i_jabs) {
3347 target_depth = depth;
3348 if (instr->i_opcode == FOR_ITER) {
3349 target_depth = depth-2;
3350 } else if (instr->i_opcode == SETUP_FINALLY ||
3351 instr->i_opcode == SETUP_EXCEPT) {
3352 target_depth = depth+3;
3353 if (target_depth > maxdepth)
3354 maxdepth = target_depth;
3355 }
3356 maxdepth = stackdepth_walk(c, instr->i_target,
3357 target_depth, maxdepth);
3358 if (instr->i_opcode == JUMP_ABSOLUTE ||
3359 instr->i_opcode == JUMP_FORWARD) {
3360 goto out; /* remaining code is dead */
3361 }
3362 }
3363 }
3364 if (b->b_next)
3365 maxdepth = stackdepth_walk(c, b->b_next, depth, maxdepth);
3366 out:
3367 b->b_seen = 0;
3368 return maxdepth;
3369 }
3370
3371 /* Find the flow path that needs the largest stack. We assume that
3372 * cycles in the flow graph have no net effect on the stack depth.
3373 */
3374 static int
3375 stackdepth(struct compiler *c)
3376 {
3377 basicblock *b, *entryblock;
3378 entryblock = NULL;
3379 for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
3380 b->b_seen = 0;
3381 b->b_startdepth = INT_MIN;
3382 entryblock = b;
3383 }
3384 if (!entryblock)
3385 return 0;
3386 return stackdepth_walk(c, entryblock, 0, 0);
3387 }
3388
3389 static int
3390 assemble_init(struct assembler *a, int nblocks, int firstlineno)
3391 {
3392 memset(a, 0, sizeof(struct assembler));
3393 a->a_lineno = firstlineno;
3394 a->a_bytecode = PyString_FromStringAndSize(NULL, DEFAULT_CODE_SIZE);
3395 if (!a->a_bytecode)
3396 return 0;
3397 a->a_lnotab = PyString_FromStringAndSize(NULL, DEFAULT_LNOTAB_SIZE);
3398 if (!a->a_lnotab)
3399 return 0;
3400 if (nblocks > PY_SIZE_MAX / sizeof(basicblock *)) {
3401 PyErr_NoMemory();
3402 return 0;
3403 }
3404 a->a_postorder = (basicblock **)PyObject_Malloc(
3405 sizeof(basicblock *) * nblocks);
3406 if (!a->a_postorder) {
3407 PyErr_NoMemory();
3408 return 0;
3409 }
3410 return 1;
3411 }
3412
3413 static void
3414 assemble_free(struct assembler *a)
3415 {
3416 Py_XDECREF(a->a_bytecode);
3417 Py_XDECREF(a->a_lnotab);
3418 if (a->a_postorder)
3419 PyObject_Free(a->a_postorder);
3420 }
3421
3422 /* Return the size of a basic block in bytes. */
3423
3424 static int
3425 instrsize(struct instr *instr)
3426 {
3427 if (!instr->i_hasarg)
3428 return 1; /* 1 byte for the opcode*/
3429 if (instr->i_oparg > 0xffff)
3430 return 6; /* 1 (opcode) + 1 (EXTENDED_ARG opcode) + 2 (oparg) + 2(oparg extended) */
3431 return 3; /* 1 (opcode) + 2 (oparg) */
3432 }
3433
3434 static int
3435 blocksize(basicblock *b)
3436 {
3437 int i;
3438 int size = 0;
3439
3440 for (i = 0; i < b->b_iused; i++)
3441 size += instrsize(&b->b_instr[i]);
3442 return size;
3443 }
3444
3445 /* Appends a pair to the end of the line number table, a_lnotab, representing
3446 the instruction's bytecode offset and line number. See
3447 Objects/lnotab_notes.txt for the description of the line number table. */
3448
3449 static int
3450 assemble_lnotab(struct assembler *a, struct instr *i)
3451 {
3452 int d_bytecode, d_lineno;
3453 int len;
3454 unsigned char *lnotab;
3455
3456 d_bytecode = a->a_offset - a->a_lineno_off;
3457 d_lineno = i->i_lineno - a->a_lineno;
3458
3459 assert(d_bytecode >= 0);
3460 assert(d_lineno >= 0);
3461
3462 if(d_bytecode == 0 && d_lineno == 0)
3463 return 1;
3464
3465 if (d_bytecode > 255) {
3466 int j, nbytes, ncodes = d_bytecode / 255;
3467 nbytes = a->a_lnotab_off + 2 * ncodes;
3468 len = PyString_GET_SIZE(a->a_lnotab);
3469 if (nbytes >= len) {
3470 if ((len <= INT_MAX / 2) && (len * 2 < nbytes))
3471 len = nbytes;
3472 else if (len <= INT_MAX / 2)
3473 len *= 2;
3474 else {
3475 PyErr_NoMemory();
3476 return 0;
3477 }
3478 if (_PyString_Resize(&a->a_lnotab, len) < 0)
3479 return 0;
3480 }
3481 lnotab = (unsigned char *)
3482 PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;
3483 for (j = 0; j < ncodes; j++) {
3484 *lnotab++ = 255;
3485 *lnotab++ = 0;
3486 }
3487 d_bytecode -= ncodes * 255;
3488 a->a_lnotab_off += ncodes * 2;
3489 }
3490 assert(d_bytecode <= 255);
3491 if (d_lineno > 255) {
3492 int j, nbytes, ncodes = d_lineno / 255;
3493 nbytes = a->a_lnotab_off + 2 * ncodes;
3494 len = PyString_GET_SIZE(a->a_lnotab);
3495 if (nbytes >= len) {
3496 if ((len <= INT_MAX / 2) && len * 2 < nbytes)
3497 len = nbytes;
3498 else if (len <= INT_MAX / 2)
3499 len *= 2;
3500 else {
3501 PyErr_NoMemory();
3502 return 0;
3503 }
3504 if (_PyString_Resize(&a->a_lnotab, len) < 0)
3505 return 0;
3506 }
3507 lnotab = (unsigned char *)
3508 PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;
3509 *lnotab++ = d_bytecode;
3510 *lnotab++ = 255;
3511 d_bytecode = 0;
3512 for (j = 1; j < ncodes; j++) {
3513 *lnotab++ = 0;
3514 *lnotab++ = 255;
3515 }
3516 d_lineno -= ncodes * 255;
3517 a->a_lnotab_off += ncodes * 2;
3518 }
3519
3520 len = PyString_GET_SIZE(a->a_lnotab);
3521 if (a->a_lnotab_off + 2 >= len) {
3522 if (_PyString_Resize(&a->a_lnotab, len * 2) < 0)
3523 return 0;
3524 }
3525 lnotab = (unsigned char *)
3526 PyString_AS_STRING(a->a_lnotab) + a->a_lnotab_off;
3527
3528 a->a_lnotab_off += 2;
3529 if (d_bytecode) {
3530 *lnotab++ = d_bytecode;
3531 *lnotab++ = d_lineno;
3532 }
3533 else { /* First line of a block; def stmt, etc. */
3534 *lnotab++ = 0;
3535 *lnotab++ = d_lineno;
3536 }
3537 a->a_lineno = i->i_lineno;
3538 a->a_lineno_off = a->a_offset;
3539 return 1;
3540 }
3541
3542 /* assemble_emit()
3543 Extend the bytecode with a new instruction.
3544 Update lnotab if necessary.
3545 */
3546
3547 static int
3548 assemble_emit(struct assembler *a, struct instr *i)
3549 {
3550 int size, arg = 0, ext = 0;
3551 Py_ssize_t len = PyString_GET_SIZE(a->a_bytecode);
3552 char *code;
3553
3554 size = instrsize(i);
3555 if (i->i_hasarg) {
3556 arg = i->i_oparg;
3557 ext = arg >> 16;
3558 }
3559 if (i->i_lineno && !assemble_lnotab(a, i))
3560 return 0;
3561 if (a->a_offset + size >= len) {
3562 if (len > PY_SSIZE_T_MAX / 2)
3563 return 0;
3564 if (_PyString_Resize(&a->a_bytecode, len * 2) < 0)
3565 return 0;
3566 }
3567 code = PyString_AS_STRING(a->a_bytecode) + a->a_offset;
3568 a->a_offset += size;
3569 if (size == 6) {
3570 assert(i->i_hasarg);
3571 *code++ = (char)EXTENDED_ARG;
3572 *code++ = ext & 0xff;
3573 *code++ = ext >> 8;
3574 arg &= 0xffff;
3575 }
3576 *code++ = i->i_opcode;
3577 if (i->i_hasarg) {
3578 assert(size == 3 || size == 6);
3579 *code++ = arg & 0xff;
3580 *code++ = arg >> 8;
3581 }
3582 return 1;
3583 }
3584
3585 static void
3586 assemble_jump_offsets(struct assembler *a, struct compiler *c)
3587 {
3588 basicblock *b;
3589 int bsize, totsize, extended_arg_count, last_extended_arg_count = 0;
3590 int i;
3591
3592 /* Compute the size of each block and fixup jump args.
3593 Replace block pointer with position in bytecode. */
3594 start:
3595 totsize = 0;
3596 for (i = a->a_nblocks - 1; i >= 0; i--) {
3597 b = a->a_postorder[i];
3598 bsize = blocksize(b);
3599 b->b_offset = totsize;
3600 totsize += bsize;
3601 }
3602 extended_arg_count = 0;
3603 for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
3604 bsize = b->b_offset;
3605 for (i = 0; i < b->b_iused; i++) {
3606 struct instr *instr = &b->b_instr[i];
3607 /* Relative jumps are computed relative to
3608 the instruction pointer after fetching
3609 the jump instruction.
3610 */
3611 bsize += instrsize(instr);
3612 if (instr->i_jabs)
3613 instr->i_oparg = instr->i_target->b_offset;
3614 else if (instr->i_jrel) {
3615 int delta = instr->i_target->b_offset - bsize;
3616 instr->i_oparg = delta;
3617 }
3618 else
3619 continue;
3620 if (instr->i_oparg > 0xffff)
3621 extended_arg_count++;
3622 }
3623 }
3624
3625 /* XXX: This is an awful hack that could hurt performance, but
3626 on the bright side it should work until we come up
3627 with a better solution.
3628
3629 In the meantime, should the goto be dropped in favor
3630 of a loop?
3631
3632 The issue is that in the first loop blocksize() is called
3633 which calls instrsize() which requires i_oparg be set
3634 appropriately. There is a bootstrap problem because
3635 i_oparg is calculated in the second loop above.
3636
3637 So we loop until we stop seeing new EXTENDED_ARGs.
3638 The only EXTENDED_ARGs that could be popping up are
3639 ones in jump instructions. So this should converge
3640 fairly quickly.
3641 */
3642 if (last_extended_arg_count != extended_arg_count) {
3643 last_extended_arg_count = extended_arg_count;
3644 goto start;
3645 }
3646 }
3647
3648 static PyObject *
3649 dict_keys_inorder(PyObject *dict, int offset)
3650 {
3651 PyObject *tuple, *k, *v;
3652 Py_ssize_t i, pos = 0, size = PyDict_Size(dict);
3653
3654 tuple = PyTuple_New(size);
3655 if (tuple == NULL)
3656 return NULL;
3657 while (PyDict_Next(dict, &pos, &k, &v)) {
3658 i = PyInt_AS_LONG(v);
3659 /* The keys of the dictionary are tuples. (see compiler_add_o)
3660 The object we want is always first, though. */
3661 k = PyTuple_GET_ITEM(k, 0);
3662 Py_INCREF(k);
3663 assert((i - offset) < size);
3664 assert((i - offset) >= 0);
3665 PyTuple_SET_ITEM(tuple, i - offset, k);
3666 }
3667 return tuple;
3668 }
3669
3670 static int
3671 compute_code_flags(struct compiler *c)
3672 {
3673 PySTEntryObject *ste = c->u->u_ste;
3674 int flags = 0, n;
3675 if (ste->ste_type != ModuleBlock)
3676 flags |= CO_NEWLOCALS;
3677 if (ste->ste_type == FunctionBlock) {
3678 if (!ste->ste_unoptimized)
3679 flags |= CO_OPTIMIZED;
3680 if (ste->ste_nested)
3681 flags |= CO_NESTED;
3682 if (ste->ste_generator)
3683 flags |= CO_GENERATOR;
3684 if (ste->ste_varargs)
3685 flags |= CO_VARARGS;
3686 if (ste->ste_varkeywords)
3687 flags |= CO_VARKEYWORDS;
3688 }
3689
3690 /* (Only) inherit compilerflags in PyCF_MASK */
3691 flags |= (c->c_flags->cf_flags & PyCF_MASK);
3692
3693 n = PyDict_Size(c->u->u_freevars);
3694 if (n < 0)
3695 return -1;
3696 if (n == 0) {
3697 n = PyDict_Size(c->u->u_cellvars);
3698 if (n < 0)
3699 return -1;
3700 if (n == 0) {
3701 flags |= CO_NOFREE;
3702 }
3703 }
3704
3705 return flags;
3706 }
3707
3708 static PyCodeObject *
3709 makecode(struct compiler *c, struct assembler *a)
3710 {
3711 PyObject *tmp;
3712 PyCodeObject *co = NULL;
3713 PyObject *consts = NULL;
3714 PyObject *names = NULL;
3715 PyObject *varnames = NULL;
3716 PyObject *filename = NULL;
3717 PyObject *name = NULL;
3718 PyObject *freevars = NULL;
3719 PyObject *cellvars = NULL;
3720 PyObject *bytecode = NULL;
3721 int nlocals, flags;
3722
3723 tmp = dict_keys_inorder(c->u->u_consts, 0);
3724 if (!tmp)
3725 goto error;
3726 consts = PySequence_List(tmp); /* optimize_code requires a list */
3727 Py_DECREF(tmp);
3728
3729 names = dict_keys_inorder(c->u->u_names, 0);
3730 varnames = dict_keys_inorder(c->u->u_varnames, 0);
3731 if (!consts || !names || !varnames)
3732 goto error;
3733
3734 cellvars = dict_keys_inorder(c->u->u_cellvars, 0);
3735 if (!cellvars)
3736 goto error;
3737 freevars = dict_keys_inorder(c->u->u_freevars, PyTuple_Size(cellvars));
3738 if (!freevars)
3739 goto error;
3740 filename = PyString_FromString(c->c_filename);
3741 if (!filename)
3742 goto error;
3743
3744 nlocals = PyDict_Size(c->u->u_varnames);
3745 flags = compute_code_flags(c);
3746 if (flags < 0)
3747 goto error;
3748
3749 bytecode = PyCode_Optimize(a->a_bytecode, consts, names, a->a_lnotab);
3750 if (!bytecode)
3751 goto error;
3752
3753 tmp = PyList_AsTuple(consts); /* PyCode_New requires a tuple */
3754 if (!tmp)
3755 goto error;
3756 Py_DECREF(consts);
3757 consts = tmp;
3758
3759 co = PyCode_New(c->u->u_argcount, nlocals, stackdepth(c), flags,
3760 bytecode, consts, names, varnames,
3761 freevars, cellvars,
3762 filename, c->u->u_name,
3763 c->u->u_firstlineno,
3764 a->a_lnotab);
3765 error:
3766 Py_XDECREF(consts);
3767 Py_XDECREF(names);
3768 Py_XDECREF(varnames);
3769 Py_XDECREF(filename);
3770 Py_XDECREF(name);
3771 Py_XDECREF(freevars);
3772 Py_XDECREF(cellvars);
3773 Py_XDECREF(bytecode);
3774 return co;
3775 }
3776
3777
3778 /* For debugging purposes only */
3779 #if 0
3780 static void
3781 dump_instr(const struct instr *i)
3782 {
3783 const char *jrel = i->i_jrel ? "jrel " : "";
3784 const char *jabs = i->i_jabs ? "jabs " : "";
3785 char arg[128];
3786
3787 *arg = '\0';
3788 if (i->i_hasarg)
3789 sprintf(arg, "arg: %d ", i->i_oparg);
3790
3791 fprintf(stderr, "line: %d, opcode: %d %s%s%s\n",
3792 i->i_lineno, i->i_opcode, arg, jabs, jrel);
3793 }
3794
3795 static void
3796 dump_basicblock(const basicblock *b)
3797 {
3798 const char *seen = b->b_seen ? "seen " : "";
3799 const char *b_return = b->b_return ? "return " : "";
3800 fprintf(stderr, "used: %d, depth: %d, offset: %d %s%s\n",
3801 b->b_iused, b->b_startdepth, b->b_offset, seen, b_return);
3802 if (b->b_instr) {
3803 int i;
3804 for (i = 0; i < b->b_iused; i++) {
3805 fprintf(stderr, " [%02d] ", i);
3806 dump_instr(b->b_instr + i);
3807 }
3808 }
3809 }
3810 #endif
3811
3812 static PyCodeObject *
3813 assemble(struct compiler *c, int addNone)
3814 {
3815 basicblock *b, *entryblock;
3816 struct assembler a;
3817 int i, j, nblocks;
3818 PyCodeObject *co = NULL;
3819
3820 /* Make sure every block that falls off the end returns None.
3821 XXX NEXT_BLOCK() isn't quite right, because if the last
3822 block ends with a jump or return b_next shouldn't set.
3823 */
3824 if (!c->u->u_curblock->b_return) {
3825 NEXT_BLOCK(c);
3826 if (addNone)
3827 ADDOP_O(c, LOAD_CONST, Py_None, consts);
3828 ADDOP(c, RETURN_VALUE);
3829 }
3830
3831 nblocks = 0;
3832 entryblock = NULL;
3833 for (b = c->u->u_blocks; b != NULL; b = b->b_list) {
3834 nblocks++;
3835 entryblock = b;
3836 }
3837
3838 /* Set firstlineno if it wasn't explicitly set. */
3839 if (!c->u->u_firstlineno) {
3840 if (entryblock && entryblock->b_instr)
3841 c->u->u_firstlineno = entryblock->b_instr->i_lineno;
3842 else
3843 c->u->u_firstlineno = 1;
3844 }
3845 if (!assemble_init(&a, nblocks, c->u->u_firstlineno))
3846 goto error;
3847 dfs(c, entryblock, &a);
3848
3849 /* Can't modify the bytecode after computing jump offsets. */
3850 assemble_jump_offsets(&a, c);
3851
3852 /* Emit code in reverse postorder from dfs. */
3853 for (i = a.a_nblocks - 1; i >= 0; i--) {
3854 b = a.a_postorder[i];
3855 for (j = 0; j < b->b_iused; j++)
3856 if (!assemble_emit(&a, &b->b_instr[j]))
3857 goto error;
3858 }
3859
3860 if (_PyString_Resize(&a.a_lnotab, a.a_lnotab_off) < 0)
3861 goto error;
3862 if (_PyString_Resize(&a.a_bytecode, a.a_offset) < 0)
3863 goto error;
3864
3865 co = makecode(c, &a);
3866 error:
3867 assemble_free(&a);
3868 return co;
3869 }
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