[libvirt] [PATCH 06/10] util: alloc: Introduce VIR_TMP

Allow preserving the holy serenity of the stack by clearing out temp pointer when leaving the scope. --- src/libvirt_private.syms | 1 + src/util/viralloc.c | 7 +++++++ src/util/viralloc.h | 15 +++++++++++++++ 3 files changed, 23 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index bae7f646fe..2f98ac901f 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1425,6 +1425,7 @@ virAllocTestHook; virAllocTestInit; virAllocTestOOM; virAllocVar; +virClearPtr; virDeleteElementsN; virDispose; virDisposeString; diff --git a/src/util/viralloc.c b/src/util/viralloc.c index e82bfa0acd..6dd19fb36b 100644 --- a/src/util/viralloc.c +++ b/src/util/viralloc.c @@ -634,3 +634,10 @@ virDisposeString(char **strptr) virDispose(strptr, strlen(*strptr), sizeof(char), NULL); } + + +void +virClearPtr(void *ptrptr) +{ + *(void **)ptrptr = NULL; +} diff --git a/src/util/viralloc.h b/src/util/viralloc.h index c8133938bf..1b1d23b3af 100644 --- a/src/util/viralloc.h +++ b/src/util/viralloc.h @@ -81,6 +81,8 @@ void virDispose(void *ptrptr, size_t count, size_t element_size, size_t *countpt ATTRIBUTE_NONNULL(1); void virDisposeString(char **strptr) ATTRIBUTE_NONNULL(1); +void virClearPtr(void *varptr) + ATTRIBUTE_NONNULL(1); /** * VIR_ALLOC: @@ -694,4 +696,17 @@ void virAllocTestHook(void (*func)(int, void*), void *data); # define VIR_AUTOUNREF(type) \ __attribute__((cleanup(virObjectAutoUnref))) type +/** + * VIR_TMP: + * @type: type of the pointer to be NULLed automatically + * + * Marks the pointer as temporary which should be cleared when leaving scope. + * + * This macro declares a temporary variable of @type which is set to NULL when + * the variable is leaving scope. This keeps the stack tidy. Note that no + * resources are freed or cleared otherwise. @type must be a pointer. + */ +# define VIR_TMP(type) \ + __attribute__((cleanup(virClearPtr))) type + #endif /* LIBVIRT_VIRALLOC_H */ -- 2.20.1