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Diffstat (limited to 'pw_preprocessor/docs.rst')
| -rw-r--r-- | pw_preprocessor/docs.rst | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/pw_preprocessor/docs.rst b/pw_preprocessor/docs.rst index ac6fd9991..15e9104e4 100644 --- a/pw_preprocessor/docs.rst +++ b/pw_preprocessor/docs.rst @@ -166,6 +166,12 @@ Macros for compiler-specific features, such as attributes or builtins. evaluates to a non zero constant integer if the attribute is supported or 0 if not. +.. c:macro:: PW_HAVE_CPP_ATTRIBUTE(x) + + Wrapper around `__has_cpp_attribute`, which was introduced in the C++20 + standard. It is supported by compilers even if C++20 is not in use. Evaluates + to a non zero constant integer if the C++ attribute is supported or 0 if not. + .. c:macro:: PW_PRAGMA(contents) Expands to a _Pragma with the contents as a string. _Pragma must take a @@ -197,6 +203,25 @@ Macros for compiler-specific features, such as attributes or builtins. // Driver handler replaced with default unless overridden. void USART_DriverHandler(void) PW_ALIAS(DefaultDriverHandler); +.. c:macro:: PW_ATTRIBUTE_LIFETIME_BOUND + + PW_ATTRIBUTE_LIFETIME_BOUND indicates that a resource owned by a function + parameter or implicit object parameter is retained by the return value of the + annotated function (or, for a parameter of a constructor, in the value of the + constructed object). This attribute causes warnings to be produced if a + temporary object does not live long enough. + + When applied to a reference parameter, the referenced object is assumed to be + retained by the return value of the function. When applied to a non-reference + parameter (for example, a pointer or a class type), all temporaries + referenced by the parameter are assumed to be retained by the return value of + the function. + + See also the upstream documentation: + https://clang.llvm.org/docs/AttributeReference.html#lifetimebound + + This is a copy of ABSL_ATTRIBUTE_LIFETIME_BOUND. + Modifying compiler diagnostics ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ``pw_preprocessor/compiler.h`` provides macros for enabling or disabling |