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[83.57.168.62]) by smtp.gmail.com with ESMTPSA id g4sm89060wro.12.2021.11.18.06.57.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Nov 2021 06:57:34 -0800 (PST) From: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH-for-6.2? v2 4/5] docs/devel/style: Render C function names as monospaced text Date: Thu, 18 Nov 2021 15:57:15 +0100 Message-Id: <20211118145716.4116731-5-philmd@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211118145716.4116731-1-philmd@redhat.com> References: <20211118145716.4116731-1-philmd@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=philmd@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=170.10.129.124; envelope-from=philmd@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.698, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , =?utf-8?q?Philippe_Mathieu-Dau?= =?utf-8?q?d=C3=A9?= , "Daniel P . Berrange" , Markus Armbruster , Darren Kenny Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add trailing parenthesis to functions and render them as monospaced text. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Alex Bennée --- docs/devel/style.rst | 66 +++++++++++++++++++++++--------------------- 1 file changed, 34 insertions(+), 32 deletions(-) diff --git a/docs/devel/style.rst b/docs/devel/style.rst index a7487d867e6..0397971e528 100644 --- a/docs/devel/style.rst +++ b/docs/devel/style.rst @@ -130,13 +130,13 @@ Function Naming Conventions Wrapped version of standard library or GLib functions use a ``qemu_`` prefix to alert readers that they are seeing a wrapped version, for -example ``qemu_strtol`` or ``qemu_mutex_lock``. Other utility functions +example ``qemu_strtol()`` or ``qemu_mutex_lock()``. Other utility functions that are widely called from across the codebase should not have any -prefix, for example ``pstrcpy`` or bit manipulation functions such as -``find_first_bit``. +prefix, for example ``pstrcpy()`` or bit manipulation functions such as +``find_first_bit()``. The ``qemu_`` prefix is also used for functions that modify global -emulator state, for example ``qemu_add_vm_change_state_handler``. +emulator state, for example ``qemu_add_vm_change_state_handler()``. However, if there is an obvious subsystem-specific prefix it should be used instead. @@ -385,15 +385,16 @@ avoided. Low level memory management =========================== -Use of the ``malloc/free/realloc/calloc/valloc/memalign/posix_memalign`` +Use of the +``malloc()/free()/realloc()/calloc()/valloc()/memalign()/posix_memalign()`` APIs is not allowed in the QEMU codebase. Instead of these routines, use the GLib memory allocation routines -``g_malloc/g_malloc0/g_new/g_new0/g_realloc/g_free`` -or QEMU's ``qemu_memalign/qemu_blockalign/qemu_vfree`` APIs. +``g_malloc()/g_malloc0()/g_new()/g_new0()/g_realloc()/g_free()`` +or QEMU's ``qemu_memalign()/qemu_blockalign()/qemu_vfree()`` APIs. -Please note that ``g_malloc`` will exit on allocation failure, so +Please note that ``g_malloc()`` will exit on allocation failure, so there is no need to test for failure (as you would have to with -``malloc``). Generally using ``g_malloc`` on start-up is fine as the +``malloc()``). Generally using ``g_malloc()`` on start-up is fine as the result of a failure to allocate memory is going to be a fatal exit anyway. There may be some start-up cases where failing is unreasonable (for example speculatively loading a large debug symbol table). @@ -401,11 +402,11 @@ anyway. There may be some start-up cases where failing is unreasonable Care should be taken to avoid introducing places where the guest could trigger an exit by causing a large allocation. For small allocations, of the order of 4k, a failure to allocate is likely indicative of an -overloaded host and allowing ``g_malloc`` to ``exit`` is a reasonable +overloaded host and allowing ``g_malloc()`` to ``exit()`` is a reasonable approach. However for larger allocations where we could realistically fall-back to a smaller one if need be we should use functions like -``g_try_new`` and check the result. For example this is valid approach -for a time/space trade-off like ``tlb_mmu_resize_locked`` in the +``g_try_new()`` and check the result. For example this is valid approach +for a time/space trade-off like ``tlb_mmu_resize_locked()`` in the SoftMMU TLB code. If the lifetime of the allocation is within the function and there are @@ -413,7 +414,7 @@ multiple exist paths you can also improve the readability of the code by using ``g_autofree`` and related annotations. See :ref:`autofree-ref` for more details. -Calling ``g_malloc`` with a zero size is valid and will return NULL. +Calling ``g_malloc()`` with a zero size is valid and will return ``NULL``. Prefer ``g_new(T, n)`` instead of ``g_malloc(sizeof(T) * n)`` for the following reasons: @@ -430,14 +431,15 @@ Declarations like are acceptable, though. -Memory allocated by ``qemu_memalign`` or ``qemu_blockalign`` must be freed with -``qemu_vfree``, since breaking this will cause problems on Win32. +Memory allocated by ``qemu_memalign()`` or ``qemu_blockalign()`` must be freed +with ``qemu_vfree()``, since breaking this will cause problems on Win32. String manipulation =================== -Do not use the strncpy function. As mentioned in the man page, it does *not* -guarantee a NULL-terminated buffer, which makes it extremely dangerous to use. +Do not use the ``strncpy()`` function. As mentioned in the man page, it does +*not* guarantee a ``NULL``-terminated buffer, which makes it extremely +dangerous to use. It also zeros trailing destination bytes out to the specified length. Instead, use this similar function when possible, but note its different signature: @@ -445,14 +447,14 @@ use this similar function when possible, but note its different signature: void pstrcpy(char *dest, int dest_buf_size, const char *src) -Don't use strcat because it can't check for buffer overflows, but: +Don't use ``strcat()`` because it can't check for buffer overflows, but: .. code-block:: c char *pstrcat(char *buf, int buf_size, const char *s) -The same limitation exists with sprintf and vsprintf, so use snprintf and -vsnprintf. +The same limitation exists with ``sprintf()`` and ``vsprintf()``, so use +``snprintf()`` and ``vsnprintf()``. QEMU provides other useful string functions: @@ -462,11 +464,11 @@ QEMU provides other useful string functions: int stristart(const char *str, const char *val, const char **ptr) int qemu_strnlen(const char *s, int max_len) -There are also replacement character processing macros for isxyz and toxyz, -so instead of e.g. isalnum you should use qemu_isalnum. +There are also replacement character processing macros for ``isxyz()`` and +``toxyz()``, so instead of e.g. ``isalnum()`` you should use ``qemu_isalnum()``. -Because of the memory management rules, you must use g_strdup/g_strndup -instead of plain strdup/strndup. +Because of the memory management rules, you must use ``g_strdup()/g_strndup()`` +instead of plain ``strdup()/strndup()``. Printf-style functions ====================== @@ -525,10 +527,10 @@ automatic cleanup: Most notably: -* g_autofree - will invoke g_free() on the variable going out of scope +* ``g_autofree`` - will invoke ``g_free()`` on the variable going out of scope -* g_autoptr - for structs / objects, will invoke the cleanup func created - by a previous use of G_DEFINE_AUTOPTR_CLEANUP_FUNC. This is +* ``g_autoptr`` - for structs / objects, will invoke the cleanup func created + by a previous use of ``G_DEFINE_AUTOPTR_CLEANUP_FUNC``. This is supported for most GLib data types and GObjects For example, instead of @@ -552,7 +554,7 @@ For example, instead of return ret; } -Using g_autofree/g_autoptr enables the code to be written as: +Using ``g_autofree/g_autoptr`` enables the code to be written as: .. code-block:: c @@ -570,13 +572,13 @@ Using g_autofree/g_autoptr enables the code to be written as: While this generally results in simpler, less leak-prone code, there are still some caveats to beware of -* Variables declared with g_auto* MUST always be initialized, +* Variables declared with ``g_auto*`` MUST always be initialized, otherwise the cleanup function will use uninitialized stack memory -* If a variable declared with g_auto* holds a value which must +* If a variable declared with ``g_auto*`` holds a value which must live beyond the life of the function, that value must be saved - and the original variable NULL'd out. This can be simpler using - g_steal_pointer + and the original variable ``NULL``'d out. This can be simpler using + ``g_steal_pointer``. .. code-block:: c