gh-151126: Fix missing PyErr_NoMemory() in remove_unused_consts (#151127)

sobolevn · web-flow · commit 3186547c1ec7 · 2026-06-09T10:03:33.000Z
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-06-09-10-28-30.gh-issue-151126.DKa6Sl.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-06-09-10-28-30.gh-issue-151126.DKa6Sl.rst
@@ -0,0 +1,3 @@
+Fix a crash, when there's no memory left on a device,
+which happened in code compilation.
+Now it raises a proper :exc:`MemoryError`.
diff --git a/Python/flowgraph.c b/Python/flowgraph.c
@@ -3279,6 +3279,7 @@ remove_unused_consts(basicblock *entryblock, PyObject *consts)
 
     index_map = PyMem_Malloc(nconsts * sizeof(Py_ssize_t));
     if (index_map == NULL) {
+        PyErr_NoMemory();
         goto end;
     }
     for (Py_ssize_t i = 1; i < nconsts; i++) {
@@ -3331,6 +3332,7 @@ remove_unused_consts(basicblock *entryblock, PyObject *consts)
     /* adjust const indices in the bytecode */
     reverse_index_map = PyMem_Malloc(nconsts * sizeof(Py_ssize_t));
     if (reverse_index_map == NULL) {
+        PyErr_NoMemory();
         goto end;
     }
     for (Py_ssize_t i = 0; i < nconsts; i++) {

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+Fix a crash, when there's no memory left on a device,`
	`2`	`+which happened in code compilation.`
	`3`	+Now it raises a proper :exc:`MemoryError`.
Original file line number	Diff line number	Diff line change
`@@ -3279,6 +3279,7 @@ remove_unused_consts(basicblock entryblock, PyObject consts)`
`3279`	`3279`
`3280`	`3280`	`index_map = PyMem_Malloc(nconsts * sizeof(Py_ssize_t));`
`3281`	`3281`	`if (index_map == NULL) {`
	`3282`	`+ PyErr_NoMemory();`
`3282`	`3283`	`goto end;`
`3283`	`3284`	`}`
`3284`	`3285`	`for (Py_ssize_t i = 1; i < nconsts; i++) {`
`@@ -3331,6 +3332,7 @@ remove_unused_consts(basicblock entryblock, PyObject consts)`
`3331`	`3332`	`/* adjust const indices in the bytecode */`
`3332`	`3333`	`reverse_index_map = PyMem_Malloc(nconsts * sizeof(Py_ssize_t));`
`3333`	`3334`	`if (reverse_index_map == NULL) {`
	`3335`	`+ PyErr_NoMemory();`
`3334`	`3336`	`goto end;`
`3335`	`3337`	`}`
`3336`	`3338`	`for (Py_ssize_t i = 0; i < nconsts; i++) {`