bpo-32436: Fix a refleak; var GC tracking; a GCC warning (#5326)

1st1 · web-flow · commit 6ab62920c879 · 2018-01-25T14:18:55.000-05:00
The refleak in question wasn't really important, as context vars
are usually created at the toplevel and live as long as the interpreter
lives, so the context var name isn't ever GCed anyways.
diff --git a/Python/context.c b/Python/context.c
@@ -134,7 +134,9 @@ PyContextVar_New(const char *name, PyObject *def)
     if (pyname == NULL) {
         return NULL;
     }
-    return contextvar_new(pyname, def);
+    PyContextVar *var = contextvar_new(pyname, def);
+    Py_DECREF(pyname);
+    return var;
 }
 
 
@@ -741,8 +743,8 @@ contextvar_new(PyObject *name, PyObject *def)
     var->var_cached_tsid = 0;
     var->var_cached_tsver = 0;
 
-    if (_PyObject_GC_IS_TRACKED(name) ||
-            (def != NULL && _PyObject_GC_IS_TRACKED(def)))
+    if (_PyObject_GC_MAY_BE_TRACKED(name) ||
+            (def != NULL && _PyObject_GC_MAY_BE_TRACKED(def)))
     {
         PyObject_GC_Track(var);
     }
diff --git a/Python/hamt.c b/Python/hamt.c
@@ -449,7 +449,7 @@ hamt_bitcount(uint32_t i)
     */
     i = i - ((i >> 1) & 0x55555555);
     i = (i & 0x33333333) + ((i >> 2) & 0x33333333);
-    return ((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
+    return (((i + (i >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;
 }
 
 static inline uint32_t

Original file line number	Diff line number	Diff line change
`@@ -134,7 +134,9 @@ PyContextVar_New(const char name, PyObject def)`
`134`	`134`	`if (pyname == NULL) {`
`135`	`135`	`return NULL;`
`136`	`136`	`}`
`137`		`- return contextvar_new(pyname, def);`
	`137`	`+ PyContextVar *var = contextvar_new(pyname, def);`
	`138`	`+ Py_DECREF(pyname);`
	`139`	`+ return var;`
`138`	`140`	`}`
`139`	`141`
`140`	`142`
`@@ -741,8 +743,8 @@ contextvar_new(PyObject name, PyObject def)`
`741`	`743`	`var->var_cached_tsid = 0;`
`742`	`744`	`var->var_cached_tsver = 0;`
`743`	`745`
`744`		`- if (_PyObject_GC_IS_TRACKED(name) \|\|`
`745`		`- (def != NULL && _PyObject_GC_IS_TRACKED(def)))`
	`746`	`+ if (_PyObject_GC_MAY_BE_TRACKED(name) \|\|`
	`747`	`+ (def != NULL && _PyObject_GC_MAY_BE_TRACKED(def)))`
`746`	`748`	`{`
`747`	`749`	`PyObject_GC_Track(var);`
`748`	`750`	`}`
Original file line number	Diff line number	Diff line change
`@@ -449,7 +449,7 @@ hamt_bitcount(uint32_t i)`
`449`	`449`	`*/`
`450`	`450`	`i = i - ((i >> 1) & 0x55555555);`
`451`	`451`	`i = (i & 0x33333333) + ((i >> 2) & 0x33333333);`
`452`		`- return ((i + (i >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;`
	`452`	`+ return (((i + (i >> 4)) & 0xF0F0F0F) * 0x1010101) >> 24;`
`453`	`453`	`}`
`454`	`454`
`455`	`455`	`static inline uint32_t`