remove max_label arg

Author: iritkatriel

Include/internal/pycore_compile.h

@@ -42,8 +42,7 @@ extern int _PyAST_Optimize(
 /* Access compiler internals for unit testing */
 PyAPI_FUNC(PyObject *) _PyCompile_OptimizeCfg(
         PyObject *instructions,
-        PyObject *consts,
-        int max_label);
+        PyObject *consts);
 
 
 #ifdef __cplusplus

Lib/test/support/bytecode_helper.py

@@ -51,7 +51,7 @@ def __repr__(self):
 class InstructionBuilder:
     def __init__(self, insts):
         self.instructions = []
-        self.max_label = 0
+        self.next_label = 0
         self.labels_map = {}
         self._populate(insts)
 
@@ -62,8 +62,8 @@ def get_label(self, lbl):
         return self.labels_map[lbl]
 
     def _newlabel(self):
-        self.max_label += 1
-        return self.max_label
+        self.next_label += 1
+        return self.next_label
 
     def _populate(self, insts):
         next_label = 0
@@ -100,7 +100,7 @@ class CfgOptimizationTestCase(unittest.TestCase):
     def get_optimized(self, insts, consts):
         bld = InstructionBuilder(insts)
         opt_insts, opt_consts = _testinternalcapi.optimize_cfg(
-            bld.instructions, consts, bld.max_label)
+            bld.instructions, consts)
 
         res = []
         for inst in opt_insts:

Modules/_testinternalcapi.c

@@ -538,17 +538,16 @@ _testinternalcapi.optimize_cfg -> object
 
   instructions: object
   consts: object
-  max_label: int
 
 Apply optimizations to instructions.
 [clinic start generated code]*/
 
 static PyObject *
 _testinternalcapi_optimize_cfg_impl(PyObject *module, PyObject *instructions,
-                                    PyObject *consts, int max_label)
-/*[clinic end generated code: output=655b9bca5750037d input=7a47589ae5c4cb84]*/
+                                    PyObject *consts)
+/*[clinic end generated code: output=5412aeafca683c8b input=6dd279570766d1bd]*/
 {
-    return _PyCompile_OptimizeCfg(instructions, consts, max_label);
+    return _PyCompile_OptimizeCfg(instructions, consts);
 }
 
 

Modules/clinic/_testinternalcapi.c.h

@@ -9614,31 +9614,36 @@ unpack_instruction(PyObject *instr, int *label, int *opcode, int *oparg,
 }
 
 static basicblock *
-instructions_to_cfg(PyObject *instructions, int max_label)
+instructions_to_cfg(PyObject *instructions)
 {
     assert(PyList_Check(instructions));
-    assert(max_label >= 0);
-    basicblock **label2block = (basicblock **)PyMem_Malloc(sizeof(basicblock *) * (max_label + 1));
+
+    Py_ssize_t num_insts = PyList_GET_SIZE(instructions);
+    Py_ssize_t max_labels = num_insts;
+    basicblock **label2block = (basicblock **)PyMem_Malloc(sizeof(basicblock *) * max_labels);
     if (!label2block) {
         PyErr_NoMemory();
     }
-    memset(label2block, 0, sizeof(basicblock *) * (max_label + 1));
+    memset(label2block, 0, sizeof(basicblock *) * max_labels);
 
     basicblock *entryblock = new_basicblock();
     if (entryblock == NULL) {
         goto error;
     }
     basicblock *current_block = entryblock;
 
-    Py_ssize_t n = PyList_GET_SIZE(instructions);
     bool start_new_block = false;
-    for (Py_ssize_t i = 0; i < n; i++) {
+    for (Py_ssize_t i = 0; i < num_insts; i++) {
         PyObject *instr_tuple = PyList_GET_ITEM(instructions, i);
         int label, opcode, oparg, target;
         struct location loc;
         if (unpack_instruction(instr_tuple, &label, &opcode, &oparg, &target, &loc) != 0) {
             goto error;
         }
+        if (label >= max_labels || target >= max_labels) {
+            PyErr_SetString(PyExc_ValueError, "label is out of range");
+            return NULL;
+        }
         basicblock *new_block = NULL;
         if (label > 0 && label2block[label] != NULL) {
             new_block = label2block[label];
@@ -9653,7 +9658,7 @@ instructions_to_cfg(PyObject *instructions, int max_label)
                 goto error;
             }
             if (label > 0) {
-                assert(label <= max_label);
+                assert(label < max_labels);
                 label2block[label] = new_block;
             }
         }
@@ -9676,7 +9681,7 @@ instructions_to_cfg(PyObject *instructions, int max_label)
         if (!basicblock_addop(current_block, opcode, oparg, target_block, &loc)) {
             goto error;
         }
-        if (IS_END_OF_BASICBLOCK_OPCODE(opcode)) {
+        if (IS_TERMINATOR_OPCODE(opcode)) {
             start_new_block = true;
         }
     }
@@ -9731,13 +9736,13 @@ cfg_to_instructions(basicblock* entryblock)
 }
 
 PyObject *
-_PyCompile_OptimizeCfg(PyObject *instructions, PyObject *consts, int max_label)
+_PyCompile_OptimizeCfg(PyObject *instructions, PyObject *consts)
 {
     PyObject *const_cache = PyDict_New();
     if (const_cache == NULL) {
         return NULL;
     }
-    basicblock *entryblock = instructions_to_cfg(instructions, max_label);
+    basicblock *entryblock = instructions_to_cfg(instructions);
     if (optimize_cfg(entryblock, consts, const_cache)) {
         goto error;
     }