diff options
| -rw-r--r-- | Lib/test/test_compile.py | 14 | ||||
| -rw-r--r-- | Python/compile.c | 88 |
2 files changed, 62 insertions, 40 deletions
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py index 21dcc1a..8bf8470 100644 --- a/Lib/test/test_compile.py +++ b/Lib/test/test_compile.py @@ -670,10 +670,22 @@ if 1: self.assertIs(f1.__code__.co_linetable, f2.__code__.co_linetable) + @support.cpython_only + def test_strip_unused_consts(self): + def f(): + "docstring" + if True: + return "used" + else: + return "unused" + + self.assertEqual(f.__code__.co_consts, + ("docstring", True, "used")) + # Stripping unused constants is not a strict requirement for the # Python semantics, it's a more an implementation detail. @support.cpython_only - def test_strip_unused_consts(self): + def test_strip_unused_None(self): # Python 3.10rc1 appended None to co_consts when None is not used # at all. See bpo-45056. def f1(): diff --git a/Python/compile.c b/Python/compile.c index 507fd04..2da36d0 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -912,6 +912,19 @@ cfg_builder_use_label(cfg_builder *g, jump_target_label lbl) return cfg_builder_maybe_start_new_block(g); } +static inline int +basicblock_append_instructions(basicblock *target, basicblock *source) +{ + for (int i = 0; i < source->b_iused; i++) { + int n = basicblock_next_instr(target); + if (n < 0) { + return -1; + } + target->b_instr[n] = source->b_instr[i]; + } + return 0; +} + static basicblock * copy_basicblock(cfg_builder *g, basicblock *block) { @@ -923,12 +936,8 @@ copy_basicblock(cfg_builder *g, basicblock *block) if (result == NULL) { return NULL; } - for (int i = 0; i < block->b_iused; i++) { - int n = basicblock_next_instr(result); - if (n < 0) { - return NULL; - } - result->b_instr[n] = block->b_instr[i]; + if (basicblock_append_instructions(result, block) < 0) { + return NULL; } return result; } @@ -7080,15 +7089,14 @@ stackdepth(basicblock *entryblock, int code_flags) if (new_depth > maxdepth) { maxdepth = new_depth; } - assert(depth >= 0); /* invalid code or bug in stackdepth() */ if (HAS_TARGET(instr->i_opcode)) { effect = stack_effect(instr->i_opcode, instr->i_oparg, 1); assert(effect != PY_INVALID_STACK_EFFECT); int target_depth = depth + effect; + assert(target_depth >= 0); /* invalid code or bug in stackdepth() */ if (target_depth > maxdepth) { maxdepth = target_depth; } - assert(target_depth >= 0); /* invalid code or bug in stackdepth() */ stackdepth_push(&sp, instr->i_target, target_depth); } depth = new_depth; @@ -7487,6 +7495,9 @@ convert_exception_handlers_to_nops(basicblock *entryblock) { } } } + for (basicblock *b = entryblock; b != NULL; b = b->b_next) { + remove_redundant_nops(b); + } } static inline void @@ -7964,8 +7975,8 @@ scan_block_for_local(int target, basicblock *b, bool unsafe_to_start, #undef MAYBE_PUSH static int -add_checks_for_loads_of_unknown_variables(basicblock *entryblock, - struct compiler *c) +add_checks_for_loads_of_uninitialized_variables(basicblock *entryblock, + struct compiler *c) { basicblock **stack = make_cfg_traversal_stack(entryblock); if (stack == NULL) { @@ -8291,7 +8302,7 @@ dump_basicblock(const basicblock *b) static int -calculate_jump_targets(basicblock *entryblock); +translate_jump_labels_to_targets(basicblock *entryblock); static int optimize_cfg(cfg_builder *g, PyObject *consts, PyObject *const_cache); @@ -8628,11 +8639,9 @@ assemble(struct compiler *c, int addNone) } nlocalsplus -= numdropped; - consts = consts_dict_keys_inorder(c->u->u_consts); - if (consts == NULL) { - goto error; - } - if (calculate_jump_targets(g->g_entryblock)) { + /** Preprocessing **/ + /* Map labels to targets and mark exception handlers */ + if (translate_jump_labels_to_targets(g->g_entryblock)) { goto error; } if (mark_except_handlers(g->g_entryblock) < 0) { @@ -8641,18 +8650,31 @@ assemble(struct compiler *c, int addNone) if (label_exception_targets(g->g_entryblock)) { goto error; } + + /** Optimization **/ + consts = consts_dict_keys_inorder(c->u->u_consts); + if (consts == NULL) { + goto error; + } if (optimize_cfg(g, consts, c->c_const_cache)) { goto error; } - if (trim_unused_consts(g->g_entryblock, consts)) { + if (add_checks_for_loads_of_uninitialized_variables(g->g_entryblock, c) < 0) { goto error; } + + /** line numbers (TODO: move this before optimization stage) */ if (duplicate_exits_without_lineno(g) < 0) { goto error; } propagate_line_numbers(g->g_entryblock); guarantee_lineno_for_exits(g->g_entryblock, c->u->u_firstlineno); + if (push_cold_blocks_to_end(g, code_flags) < 0) { + goto error; + } + + /** Assembly **/ int maxdepth = stackdepth(g->g_entryblock, code_flags); if (maxdepth < 0) { goto error; @@ -8661,27 +8683,19 @@ assemble(struct compiler *c, int addNone) convert_exception_handlers_to_nops(g->g_entryblock); - if (push_cold_blocks_to_end(g, code_flags) < 0) { - goto error; - } - for (basicblock *b = g->g_entryblock; b != NULL; b = b->b_next) { - remove_redundant_nops(b); - } - /* Order of basic blocks must have been determined by now */ if (normalize_jumps(g) < 0) { goto error; } - if (add_checks_for_loads_of_unknown_variables(g->g_entryblock, c) < 0) { - goto error; - } - assert(no_redundant_jumps(g)); /* Can't modify the bytecode after computing jump offsets. */ assemble_jump_offsets(g->g_entryblock); + if (trim_unused_consts(g->g_entryblock, consts)) { + goto error; + } /* Create assembler */ if (!assemble_init(&a, c->u->u_firstlineno)) @@ -9265,12 +9279,8 @@ inline_small_exit_blocks(basicblock *bb) { basicblock *target = last->i_target; if (basicblock_exits_scope(target) && target->b_iused <= MAX_COPY_SIZE) { last->i_opcode = NOP; - for (int i = 0; i < target->b_iused; i++) { - int index = basicblock_next_instr(bb); - if (index < 0) { - return -1; - } - bb->b_instr[index] = target->b_instr[i]; + if (basicblock_append_instructions(bb, target) < 0) { + return -1; } return 1; } @@ -9456,7 +9466,7 @@ propagate_line_numbers(basicblock *entryblock) { /* Calculate the actual jump target from the target_label */ static int -calculate_jump_targets(basicblock *entryblock) +translate_jump_labels_to_targets(basicblock *entryblock) { int max_label = -1; for (basicblock *b = entryblock; b != NULL; b = b->b_next) { @@ -9599,12 +9609,14 @@ is_exit_without_lineno(basicblock *b) { static int duplicate_exits_without_lineno(cfg_builder *g) { + assert(no_empty_basic_blocks(g)); /* Copy all exit blocks without line number that are targets of a jump. */ basicblock *entryblock = g->g_entryblock; for (basicblock *b = entryblock; b != NULL; b = b->b_next) { struct instr *last = basicblock_last_instr(b); - if (last != NULL && is_jump(last)) { + assert(last != NULL); + if (is_jump(last)) { basicblock *target = last->i_target; if (is_exit_without_lineno(target) && target->b_predecessors > 1) { basicblock *new_target = copy_basicblock(g, target); @@ -9621,8 +9633,6 @@ duplicate_exits_without_lineno(cfg_builder *g) } } - assert(no_empty_basic_blocks(g)); - /* Any remaining reachable exit blocks without line number can only be reached by * fall through, and thus can only have a single predecessor */ for (basicblock *b = entryblock; b != NULL; b = b->b_next) { @@ -9775,7 +9785,7 @@ _PyCompile_OptimizeCfg(PyObject *instructions, PyObject *consts) if (const_cache == NULL) { goto error; } - if (calculate_jump_targets(g.g_entryblock)) { + if (translate_jump_labels_to_targets(g.g_entryblock)) { goto error; } if (optimize_cfg(&g, consts, const_cache) < 0) { |