Fix compiler warnings and check slot offset can be stored in index field

markshannon · markshannon · commit b07f219a01c1 · 2021-06-09T13:23:52.000+01:00
diff --git a/Python/specialize.c b/Python/specialize.c
@@ -257,7 +257,7 @@ specialize_module_load_attr(
         return -1;
     }
     cache1->dk_version_or_hint = keys_version;
-    cache0->index = index;
+    cache0->index = (uint16_t)index;
     *instr = _Py_MAKECODEUNIT(LOAD_ATTR_MODULE, _Py_OPARG(*instr));
     return 0;
 }
@@ -298,8 +298,11 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, Sp
             goto fail;
         }
         Py_ssize_t offset = dmem->offset;
+        if (offset != (uint16_t)offset) {
+            goto fail;
+        }
         assert(offset > 0);
-        cache0->index = offset;
+        cache0->index = (uint16_t)offset;
         cache1->tp_version = type->tp_version_tag;
         *instr = _Py_MAKECODEUNIT(LOAD_ATTR_SLOT, _Py_OPARG(*instr));
         goto success;
@@ -336,7 +339,7 @@ _Py_Specialize_LoadAttr(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name, Sp
         }
         cache1->dk_version_or_hint = keys_version;
         cache1->tp_version = type->tp_version_tag;
-        cache0->index = index;
+        cache0->index = (uint16_t)index;
         *instr = _Py_MAKECODEUNIT(LOAD_ATTR_SPLIT_KEYS, _Py_OPARG(*instr));
         goto success;
     }

Original file line number	Diff line number	Diff line change
`@@ -257,7 +257,7 @@ specialize_module_load_attr(`
`257`	`257`	`return -1;`
`258`	`258`	`}`
`259`	`259`	`cache1->dk_version_or_hint = keys_version;`
`260`		`- cache0->index = index;`
	`260`	`+ cache0->index = (uint16_t)index;`
`261`	`261`	`instr = _Py_MAKECODEUNIT(LOAD_ATTR_MODULE, _Py_OPARG(instr));`
`262`	`262`	`return 0;`
`263`	`263`	`}`
`@@ -298,8 +298,11 @@ _Py_Specialize_LoadAttr(PyObject owner, _Py_CODEUNIT instr, PyObject *name, Sp`
`298`	`298`	`goto fail;`
`299`	`299`	`}`
`300`	`300`	`Py_ssize_t offset = dmem->offset;`
	`301`	`+ if (offset != (uint16_t)offset) {`
	`302`	`+ goto fail;`
	`303`	`+ }`
`301`	`304`	`assert(offset > 0);`
`302`		`- cache0->index = offset;`
	`305`	`+ cache0->index = (uint16_t)offset;`
`303`	`306`	`cache1->tp_version = type->tp_version_tag;`
`304`	`307`	`instr = _Py_MAKECODEUNIT(LOAD_ATTR_SLOT, _Py_OPARG(instr));`
`305`	`308`	`goto success;`
`@@ -336,7 +339,7 @@ _Py_Specialize_LoadAttr(PyObject owner, _Py_CODEUNIT instr, PyObject *name, Sp`
`336`	`339`	`}`
`337`	`340`	`cache1->dk_version_or_hint = keys_version;`
`338`	`341`	`cache1->tp_version = type->tp_version_tag;`
`339`		`- cache0->index = index;`
	`342`	`+ cache0->index = (uint16_t)index;`
`340`	`343`	`instr = _Py_MAKECODEUNIT(LOAD_ATTR_SPLIT_KEYS, _Py_OPARG(instr));`
`341`	`344`	`goto success;`
`342`	`345`	`}`