r201715 - Moving the documentation for the clang::fallthrough attribute into AttrDocs.
Aaron Ballman
aaron at aaronballman.com
Wed Feb 19 12:56:52 PST 2014
Author: aaronballman
Date: Wed Feb 19 14:56:51 2014
New Revision: 201715
URL: http://llvm.org/viewvc/llvm-project?rev=201715&view=rev
Log:
Moving the documentation for the clang::fallthrough attribute into AttrDocs.
Modified:
cfe/trunk/docs/LanguageExtensions.rst
cfe/trunk/include/clang/Basic/Attr.td
cfe/trunk/include/clang/Basic/AttrDocs.td
Modified: cfe/trunk/docs/LanguageExtensions.rst
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/docs/LanguageExtensions.rst?rev=201715&r1=201714&r2=201715&view=diff
==============================================================================
--- cfe/trunk/docs/LanguageExtensions.rst (original)
+++ cfe/trunk/docs/LanguageExtensions.rst Wed Feb 19 14:56:51 2014
@@ -1570,51 +1570,6 @@ Non-standard C++11 Attributes
Clang's non-standard C++11 attributes live in the ``clang`` attribute
namespace.
-The ``clang::fallthrough`` attribute
-------------------------------------
-
-The ``clang::fallthrough`` attribute is used along with the
-``-Wimplicit-fallthrough`` argument to annotate intentional fall-through
-between switch labels. It can only be applied to a null statement placed at a
-point of execution between any statement and the next switch label. It is
-common to mark these places with a specific comment, but this attribute is
-meant to replace comments with a more strict annotation, which can be checked
-by the compiler. This attribute doesn't change semantics of the code and can
-be used wherever an intended fall-through occurs. It is designed to mimic
-control-flow statements like ``break;``, so it can be placed in most places
-where ``break;`` can, but only if there are no statements on the execution path
-between it and the next switch label.
-
-Here is an example:
-
-.. code-block:: c++
-
- // compile with -Wimplicit-fallthrough
- switch (n) {
- case 22:
- case 33: // no warning: no statements between case labels
- f();
- case 44: // warning: unannotated fall-through
- g();
- [[clang::fallthrough]];
- case 55: // no warning
- if (x) {
- h();
- break;
- }
- else {
- i();
- [[clang::fallthrough]];
- }
- case 66: // no warning
- p();
- [[clang::fallthrough]]; // warning: fallthrough annotation does not
- // directly precede case label
- q();
- case 77: // warning: unannotated fall-through
- r();
- }
-
``gnu::`` attributes
--------------------
Modified: cfe/trunk/include/clang/Basic/Attr.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=201715&r1=201714&r2=201715&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Attr.td (original)
+++ cfe/trunk/include/clang/Basic/Attr.td Wed Feb 19 14:56:51 2014
@@ -642,7 +642,7 @@ def ExtVectorType : Attr {
def FallThrough : Attr {
let Spellings = [CXX11<"clang", "fallthrough">];
// let Subjects = [NullStmt];
- let Documentation = [Undocumented];
+ let Documentation = [FallthroughDocs];
}
def FastCall : InheritableAttr {
Modified: cfe/trunk/include/clang/Basic/AttrDocs.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/AttrDocs.td?rev=201715&r1=201714&r2=201715&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/AttrDocs.td (original)
+++ cfe/trunk/include/clang/Basic/AttrDocs.td Wed Feb 19 14:56:51 2014
@@ -410,3 +410,50 @@ When one method overrides another, the o
@end
}];
}
+
+def FallthroughDocs : Documentation {
+ let Category = DocCatStmt;
+ let Content = [{
+The ``clang::fallthrough`` attribute is used along with the
+``-Wimplicit-fallthrough`` argument to annotate intentional fall-through
+between switch labels. It can only be applied to a null statement placed at a
+point of execution between any statement and the next switch label. It is
+common to mark these places with a specific comment, but this attribute is
+meant to replace comments with a more strict annotation, which can be checked
+by the compiler. This attribute doesn't change semantics of the code and can
+be used wherever an intended fall-through occurs. It is designed to mimic
+control-flow statements like ``break;``, so it can be placed in most places
+where ``break;`` can, but only if there are no statements on the execution path
+between it and the next switch label.
+
+Here is an example:
+
+.. code-block:: c++
+
+ // compile with -Wimplicit-fallthrough
+ switch (n) {
+ case 22:
+ case 33: // no warning: no statements between case labels
+ f();
+ case 44: // warning: unannotated fall-through
+ g();
+ [[clang::fallthrough]];
+ case 55: // no warning
+ if (x) {
+ h();
+ break;
+ }
+ else {
+ i();
+ [[clang::fallthrough]];
+ }
+ case 66: // no warning
+ p();
+ [[clang::fallthrough]]; // warning: fallthrough annotation does not
+ // directly precede case label
+ q();
+ case 77: // warning: unannotated fall-through
+ r();
+ }
+ }];
+}
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