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Diffstat (limited to 'docs/LanguageExtensions.html')
| -rw-r--r-- | docs/LanguageExtensions.html | 119 |
1 files changed, 68 insertions, 51 deletions
diff --git a/docs/LanguageExtensions.html b/docs/LanguageExtensions.html index 8f43725d82a2..7ee8f010a32b 100644 --- a/docs/LanguageExtensions.html +++ b/docs/LanguageExtensions.html @@ -1,13 +1,17 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" + "http://www.w3.org/TR/html4/strict.dtd"> +<!-- Material used from: HTML 4.01 specs: http://www.w3.org/TR/html401/ --> <html> <head> -<title>Clang Language Extensions</title> -<link type="text/css" rel="stylesheet" href="../menu.css" /> -<link type="text/css" rel="stylesheet" href="../content.css" /> -<style type="text/css"> -td { - vertical-align: top; -} -</style> + <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> + <title>Clang LanguageExtensions</title> + <link type="text/css" rel="stylesheet" href="../menu.css"> + <link type="text/css" rel="stylesheet" href="../content.css"> + <style type="text/css"> + td { + vertical-align: top; + } + </style> </head> <body> @@ -25,12 +29,12 @@ td { <li><a href="#vectors">Vectors and Extended Vectors</a></li> <li><a href="#deprecated">Messages on <tt>deprecated</tt> and <tt>unavailable</tt> attributes</a></li> <li><a href="#attributes-on-enumerators">Attributes on enumerators</a></li> -<li><a href="#checking_language_features">Checks for Standard Language Features</a></li> +<li><a href="#checking_language_features">Checks for Standard Language Features</a> <ul> <li><a href="#cxx_exceptions">C++ exceptions</a></li> <li><a href="#cxx_rtti">C++ RTTI</a></li> - </ul> -<li><a href="#checking_upcoming_features">Checks for Upcoming Standard Language Features</a></li> + </ul></li> +<li><a href="#checking_upcoming_features">Checks for Upcoming Standard Language Features</a> <ul> <li><a href="#cxx0x">C++0x</a> <ul> @@ -39,6 +43,7 @@ td { <li><a href="#cxx_alias_templates">C++0x alias templates</a></li> <li><a href="#cxx_attributes">C++0x attributes</a></li> <li><a href="#cxx_default_function_template_args">C++0x default template arguments in function templates</a></li> + <li><a href="#cxx_delegating_constructor">C++0x delegating constructors</a></li> <li><a href="#cxx_deleted_functions">C++0x deleted functions</a></li> <li><a href="#cxx_lambdas">C++0x lambdas</a></li> <li><a href="#cxx_nullptr">C++0x nullptr</a></li> @@ -53,18 +58,19 @@ td { <li><a href="#cxx_strong_enums">C++0x strongly-typed enumerations</a></li> <li><a href="#cxx_trailing_return">C++0x trailing return type</a></li> <li><a href="#cxx_noexcept">C++0x noexcept specification</a></li> - </ul> + </ul></li> <li><a href="#c1x">C1X</a> <ul> <li><a href="#c_generic_selections">C1X generic selections</a></li> <li><a href="#c_static_assert">C1X <tt>_Static_assert()</tt></a></li> - </ul> - </ul> + </ul></li> + </ul> </li> <li><a href="#checking_type_traits">Checks for Type Traits</a></li> <li><a href="#blocks">Blocks</a></li> <li><a href="#objc_features">Objective-C Features</a> <ul> <li><a href="#objc_instancetype">Related result types</a></li> + <li><a href="#objc_arc">Automatic reference counting</a></li> </ul> </li> <li><a href="#overloading-in-c">Function Overloading in C</a></li> @@ -104,7 +110,7 @@ code without having to resort to something like autoconf or fragile "compiler version checks".</p> <!-- ======================================================================= --> -<h3 id="__has_builtin">__has_builtin</h3> +<h3><a name="__has_builtin">__has_builtin</a></h3> <!-- ======================================================================= --> <p>This function-like macro takes a single identifier argument that is the name @@ -129,7 +135,7 @@ not. It can be used like this:</p> <!-- ======================================================================= --> -<h3 id="__has_feature_extension">__has_feature and __has_extension</h3> +<h3><a name="__has_feature_extension"> __has_feature and __has_extension</a></h3> <!-- ======================================================================= --> <p>These function-like macros take a single identifier argument that is the @@ -174,7 +180,7 @@ non-standardized features, i.e. features not prefixed <code>c_</code>, <p>The feature tag is described along with the language feature below.</p> <!-- ======================================================================= --> -<h3 id="__has_attribute">__has_attribute</h3> +<h3><a name="__has_attribute">__has_attribute</a></h3> <!-- ======================================================================= --> <p>This function-like macro takes a single identifier argument that is the name @@ -208,7 +214,7 @@ check for the existence of an include file before doing a possibly failing #include directive.</p> <!-- ======================================================================= --> -<h3 id="__has_include">__has_include</h3> +<h3><a name="__has_include">__has_include</a></h3> <!-- ======================================================================= --> <p>This function-like macro takes a single file name string argument that @@ -218,12 +224,12 @@ be found using the include paths, or 0 otherwise:</p> <blockquote> <pre> // Note the two possible file name string formats. -#if __has_include("myinclude.h") && __has_include(<stdint.h>) +#if __has_include("myinclude.h") && __has_include(<stdint.h>) # include "myinclude.h" #endif // To avoid problem with non-clang compilers not having this macro. -#if defined(__has_include) && __has_include("myinclude.h") +#if defined(__has_include) && __has_include("myinclude.h") # include "myinclude.h" #endif </pre> @@ -232,7 +238,7 @@ be found using the include paths, or 0 otherwise:</p> <p>To test for this feature, use #if defined(__has_include).</p> <!-- ======================================================================= --> -<h3 id="__has_include_next">__has_include_next</h3> +<h3><a name="__has_include_next">__has_include_next</a></h3> <!-- ======================================================================= --> <p>This function-like macro takes a single file name string argument that @@ -244,12 +250,12 @@ be found using the include paths, or 0 otherwise:</p> <blockquote> <pre> // Note the two possible file name string formats. -#if __has_include_next("myinclude.h") && __has_include_next(<stdint.h>) +#if __has_include_next("myinclude.h") && __has_include_next(<stdint.h>) # include_next "myinclude.h" #endif // To avoid problem with non-clang compilers not having this macro. -#if defined(__has_include_next) && __has_include_next("myinclude.h") +#if defined(__has_include_next) && __has_include_next("myinclude.h") # include_next "myinclude.h" #endif </pre> @@ -410,115 +416,120 @@ noted.</p> C++0x standard. As a result, all these features are enabled with the <tt>-std=c++0x</tt> option when compiling C++ code.</p> -<h4 id="cxx_decltype">C++0x <tt>decltype()</tt></h3> +<h4 id="cxx_decltype">C++0x <tt>decltype()</tt></h4> <p>Use <tt>__has_feature(cxx_decltype)</tt> or <tt>__has_extension(cxx_decltype)</tt> to determine if support for the <tt>decltype()</tt> specifier is enabled.</p> -<h4 id="cxx_access_control_sfinae">C++0x SFINAE includes access control</h3> +<h4 id="cxx_access_control_sfinae">C++0x SFINAE includes access control</h4> <p>Use <tt>__has_feature(cxx_access_control_sfinae)</tt> or <tt>__has_extension(cxx_access_control_sfinae)</tt> to determine whether access-control errors (e.g., calling a private constructor) are considered to be template argument deduction errors (aka SFINAE errors), per <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1170">C++ DR1170</a>.</p> -<h4 id="cxx_alias_templates">C++0x alias templates</h3> +<h4 id="cxx_alias_templates">C++0x alias templates</h4> <p>Use <tt>__has_feature(cxx_alias_templates)</tt> or <tt>__has_extension(cxx_alias_templates)</tt> to determine if support for C++0x's alias declarations and alias templates is enabled.</p> -<h4 id="cxx_attributes">C++0x attributes</h3> +<h4 id="cxx_attributes">C++0x attributes</h4> <p>Use <tt>__has_feature(cxx_attributes)</tt> or <tt>__has_extension(cxx_attributes)</tt> to determine if support for attribute parsing with C++0x's square bracket notation is enabled.</p> -<h4 id="cxx_default_function_template_args">C++0x default template arguments in function templates</h3> +<h4 id="cxx_default_function_template_args">C++0x default template arguments in function templates</h4> <p>Use <tt>__has_feature(cxx_default_function_template_args)</tt> or <tt>__has_extension(cxx_default_function_template_args)</tt> to determine if support for default template arguments in function templates is enabled.</p> -<h4 id="cxx_deleted_functions">C++0x deleted functions</tt></h3> +<h4 id="cxx_delegating_constructors">C++0x delegating constructors</h4> + +<p>Use <tt>__has_feature(cxx_delegating_constructors)</tt> to determine if +support for delegating constructors is enabled.</p> + +<h4 id="cxx_deleted_functions">C++0x <tt>delete</tt>d functions</h4> <p>Use <tt>__has_feature(cxx_deleted_functions)</tt> or <tt>__has_extension(cxx_deleted_functions)</tt> to determine if support for deleted function definitions (with <tt>= delete</tt>) is enabled.</p> -<h4 id="cxx_lambdas">C++0x lambdas</h3> +<h4 id="cxx_lambdas">C++0x lambdas</h4> <p>Use <tt>__has_feature(cxx_lambdas)</tt> or <tt>__has_extension(cxx_lambdas)</tt> to determine if support for lambdas is enabled. clang does not currently implement this feature.</p> -<h4 id="cxx_nullptr">C++0x <tt>nullptr</tt></h3> +<h4 id="cxx_nullptr">C++0x <tt>nullptr</tt></h4> <p>Use <tt>__has_feature(cxx_nullptr)</tt> or <tt>__has_extension(cxx_nullptr)</tt> to determine if support for <tt>nullptr</tt> is enabled.</p> -<h4 id="cxx_override_control">C++0x <tt>override control</tt></h3> +<h4 id="cxx_override_control">C++0x <tt>override control</tt></h4> <p>Use <tt>__has_feature(cxx_override_control)</tt> or <tt>__has_extension(cxx_override_control)</tt> to determine if support for the override control keywords is enabled.</p> -<h4 id="cxx_reference_qualified_functions">C++0x reference-qualified functions</h3> +<h4 id="cxx_reference_qualified_functions">C++0x reference-qualified functions</h4> <p>Use <tt>__has_feature(cxx_reference_qualified_functions)</tt> or <tt>__has_extension(cxx_reference_qualified_functions)</tt> to determine if support for reference-qualified functions (e.g., member functions with <code>&</code> or <code>&&</code> applied to <code>*this</code>) is enabled.</p> -<h4 id="cxx_range_for">C++0x range-based for loop</tt></h3> +<h4 id="cxx_range_for">C++0x range-based <tt>for</tt> loop</h4> <p>Use <tt>__has_feature(cxx_range_for)</tt> or <tt>__has_extension(cxx_range_for)</tt> to determine if support for the range-based for loop is enabled. </p> -<h4 id="cxx_rvalue_references">C++0x rvalue references</tt></h3> +<h4 id="cxx_rvalue_references">C++0x rvalue references</h4> <p>Use <tt>__has_feature(cxx_rvalue_references)</tt> or <tt>__has_extension(cxx_rvalue_references)</tt> to determine if support for rvalue references is enabled. </p> -<h4 id="cxx_static_assert">C++0x <tt>static_assert()</tt></h3> +<h4 id="cxx_static_assert">C++0x <tt>static_assert()</tt></h4> <p>Use <tt>__has_feature(cxx_static_assert)</tt> or <tt>__has_extension(cxx_static_assert)</tt> to determine if support for compile-time assertions using <tt>static_assert</tt> is enabled.</p> -<h4 id="cxx_auto_type">C++0x type inference</h3> +<h4 id="cxx_auto_type">C++0x type inference</h4> <p>Use <tt>__has_feature(cxx_auto_type)</tt> or <tt>__has_extension(cxx_auto_type)</tt> to determine C++0x type inference is supported using the <tt>auto</tt> specifier. If this is disabled, <tt>auto</tt> will instead be a storage class specifier, as in C or C++98.</p> -<h4 id="cxx_variadic_templates">C++0x variadic templates</h3> +<h4 id="cxx_variadic_templates">C++0x variadic templates</h4> <p>Use <tt>__has_feature(cxx_variadic_templates)</tt> or <tt>__has_extension(cxx_variadic_templates)</tt> to determine if support for variadic templates is enabled.</p> -<h4 id="cxx_inline_namespaces">C++0x inline namespaces</h3> +<h4 id="cxx_inline_namespaces">C++0x inline namespaces</h4> <p>Use <tt>__has_feature(cxx_inline_namespaces)</tt> or <tt>__has_extension(cxx_inline_namespaces)</tt> to determine if support for inline namespaces is enabled.</p> -<h4 id="cxx_trailing_return">C++0x trailing return type</h3> +<h4 id="cxx_trailing_return">C++0x trailing return type</h4> <p>Use <tt>__has_feature(cxx_trailing_return)</tt> or <tt>__has_extension(cxx_trailing_return)</tt> to determine if support for the alternate function declaration syntax with trailing return type is enabled.</p> -<h4 id="cxx_noexcept">C++0x noexcept</h3> +<h4 id="cxx_noexcept">C++0x noexcept</h4> <p>Use <tt>__has_feature(cxx_noexcept)</tt> or <tt>__has_extension(cxx_noexcept)</tt> to determine if support for noexcept exception specifications is enabled.</p> -<h4 id="cxx_strong_enums">C++0x strongly typed enumerations</h3> +<h4 id="cxx_strong_enums">C++0x strongly typed enumerations</h4> <p>Use <tt>__has_feature(cxx_strong_enums)</tt> or <tt>__has_extension(cxx_strong_enums)</tt> to determine if support for @@ -530,7 +541,7 @@ strongly typed, scoped enumerations is enabled.</p> C1X standard. As a result, all these features are enabled with the <tt>-std=c1x</tt> option when compiling C code.</p> -<h4 id="c_generic_selections">C1X generic selections</h2> +<h4 id="c_generic_selections">C1X generic selections</h4> <p>Use <tt>__has_feature(c_generic_selections)</tt> or <tt>__has_extension(c_generic_selections)</tt> to determine if support for @@ -544,7 +555,7 @@ C1X draft standard.</p> appropriate standard, but in C++, which lacks the type compatibility rules used in C, types are considered compatible only if they are equivalent.</p> -<h4 id="c_static_assert">C1X <tt>_Static_assert()</tt></h3> +<h4 id="c_static_assert">C1X <tt>_Static_assert()</tt></h4> <p>Use <tt>__has_feature(c_static_assert)</tt> or <tt>__has_extension(c_static_assert)</tt> to determine if support for @@ -554,7 +565,7 @@ compile-time assertions using <tt>_Static_assert</tt> is enabled.</p> <h2 id="checking_type_traits">Checks for Type Traits</h2> <!-- ======================================================================= --> -<p>Clang supports the <a hef="http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html">GNU C++ type traits</a> and a subset of the <a href="http://msdn.microsoft.com/en-us/library/ms177194(v=VS.100).aspx">Microsoft Visual C++ Type traits</a>. For each supported type trait <code>__X</code>, <code>__has_extension(X)</code> indicates the presence of the type trait. For example: +<p>Clang supports the <a href="http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html">GNU C++ type traits</a> and a subset of the <a href="http://msdn.microsoft.com/en-us/library/ms177194(v=VS.100).aspx">Microsoft Visual C++ Type traits</a>. For each supported type trait <code>__X</code>, <code>__has_extension(X)</code> indicates the presence of the type trait. For example: <blockquote> <pre> #if __has_extension(is_convertible_to) @@ -640,7 +651,7 @@ to have the type <code>NSArray *</code>. If neither <code>alloc</code> nor <code <p>To determine whether a method has a related result type, the first word in the camel-case selector (e.g., "init" in "initWithObjects") is considered, and the method will a related result type if its return -type is compatible with the type of its class and if +type is compatible with the type of its class and if</p> <ul> @@ -650,7 +661,7 @@ type is compatible with the type of its class and if <li>the first word is "autorelease", "init", "retain", or "self", and the method is an instance method.</li> -</ul></p> +</ul> <p>If a method with a related result type is overridden by a subclass method, the subclass method must also return a type that is compatible @@ -670,6 +681,12 @@ with a related result type is treated the same way as method without a related result type.</p> <!-- ======================================================================= --> +<h2 id="objc_arc">Automatic reference counting </h2> +<!-- ======================================================================= --> + +<p>Clang provides support for <a href="AutomaticReferenceCounting.html">automated reference counting</a> in Objective-C, which eliminates the need for manual retain/release/autorelease message sends. There are two feature macros associated with automatic reference counting: <code>__has_feature(objc_arc)</code> indicates the availability of automated reference counting in general, while <code>__has_feature(objc_arc_weak)</code> indicates that automated reference counting also includes support for <code>__weak</code> pointers to Objective-C objects.</p> + +<!-- ======================================================================= --> <h2 id="overloading-in-c">Function Overloading in C</h2> <!-- ======================================================================= --> @@ -790,7 +807,7 @@ vector support</a> instead of builtins, in order to reduce the number of builtins that we need to implement.</p> <!-- ======================================================================= --> -<h3 id="__builtin_shufflevector">__builtin_shufflevector</h3> +<h3><a name="__builtin_shufflevector">__builtin_shufflevector</a></h3> <!-- ======================================================================= --> <p><tt>__builtin_shufflevector</tt> is used to express generic vector @@ -842,7 +859,7 @@ the number of indices specified. <p>Query for this feature with __has_builtin(__builtin_shufflevector).</p> <!-- ======================================================================= --> -<h3 id="__builtin_unreachable">__builtin_unreachable</h3> +<h3><a name="__builtin_unreachable">__builtin_unreachable</a></h3> <!-- ======================================================================= --> <p><tt>__builtin_unreachable</tt> is used to indicate that a specific point in @@ -880,7 +897,7 @@ no arguments and produces a void result. <p>Query for this feature with __has_builtin(__builtin_unreachable).</p> <!-- ======================================================================= --> -<h3 id="__sync_swap">__sync_swap</h3> +<h3><a name="__sync_swap">__sync_swap</a></h3> <!-- ======================================================================= --> <p><tt>__sync_swap</tt> is used to atomically swap integers or pointers in @@ -896,7 +913,7 @@ memory. <p><b>Example of Use:</b></p> <pre> -int old_value = __sync_swap(&value, new_value); +int old_value = __sync_swap(&value, new_value); </pre> <p><b>Description:</b></p> |