forked from OSchip/llvm-project
83 lines
1.4 KiB
ReStructuredText
83 lines
1.4 KiB
ReStructuredText
.. index:: Use-Nullptr Transform
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=====================
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Use-Nullptr Transform
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=====================
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The Use-Nullptr Transform is a transformation to convert the usage of null
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pointer constants (eg. ``NULL``, ``0``) to use the new C++11 ``nullptr``
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keyword. The transform is enabled with the :option:`-use-nullptr` option of
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:program:`cpp11-migrate`.
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Example
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=======
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.. code-block:: c++
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void assignment() {
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char *a = NULL;
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char *b = 0;
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char c = 0;
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}
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int *ret_ptr() {
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return 0;
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}
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transforms to:
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.. code-block:: c++
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void assignment() {
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char *a = nullptr;
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char *b = nullptr;
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char c = 0;
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}
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int *ret_ptr() {
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return nullptr;
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}
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User defined macros
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===================
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By default this transform will only replace the ``NULL`` macro and will skip any
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user-defined macros that behaves like ``NULL``. The user can use the
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:option:`-user-null-macros` option to specify a comma-separated list of macro
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names that will be transformed along with ``NULL``.
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Example
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-------
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.. code-block:: c++
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#define MY_NULL (void*)0
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void assignment() {
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void *p = MY_NULL;
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}
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using the command-line
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.. code-block:: bash
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cpp11-migrate -use-nullptr -user-null-macros=MY_NULL foo.cpp
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transforms to:
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.. code-block:: c++
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#define MY_NULL NULL
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void assignment() {
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int *p = nullptr;
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}
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Risk
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====
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:option:`-risk` has no effect in this transform.
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