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| author | Lubos Lunak <l.lunak@suse.cz> | 2013-07-14 01:16:18 +0200 |
|---|---|---|
| committer | Jason Merrill <jason@gcc.gnu.org> | 2013-07-13 19:16:18 -0400 |
| commit | 2a99e5e633fb1faddeb8c8ce7b1429dedebb033b (patch) | |
| tree | 0170fc55d95b627aec9918256ba3cf861f269fd3 /gcc/doc/extend.texi | |
| parent | 286e8fc16fb582ee1cb3869aafb87309542a55ec (diff) | |
| download | gcc-2a99e5e633fb1faddeb8c8ce7b1429dedebb033b.zip gcc-2a99e5e633fb1faddeb8c8ce7b1429dedebb033b.tar.gz gcc-2a99e5e633fb1faddeb8c8ce7b1429dedebb033b.tar.bz2 | |
re PR c++/55203 (No unused warning for variables of non-trivial types)
PR c++/55203
c-family/
* c-common.c (c_common_attribute_table): Add warn_unused.
(handle_warn_unused_attribute): New.
cp/
* init.c (build_aggr_init): Check for warn_unused attribute.
* decl.c (poplevel): Likewise.
From-SVN: r200941
Diffstat (limited to 'gcc/doc/extend.texi')
| -rw-r--r-- | gcc/doc/extend.texi | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi index 1c85a3e..721c9b1 100644 --- a/gcc/doc/extend.texi +++ b/gcc/doc/extend.texi @@ -16377,6 +16377,23 @@ only be applied to classes declared within an @code{extern "Java"} block. Calls to methods declared in this interface are dispatched using GCJ's interface table mechanism, instead of regular virtual table dispatch. +@item warn_unused +@cindex @code{warn_unused} attribute + +For C++ types with non-trivial constructors and/or destructors it is +impossible for the compiler to determine whether a variable of this +type is truly unused if it is not referenced. This type attribute +informs the compiler that variables of this type should be warned +about if they appear to be unused, just like variables of fundamental +types. + +This attribute is appropriate for types which just represent a value, +such as @code{std::string}; it is not appropriate for types which +control a resource, such as @code{std::mutex}. + +This attribute is also accepted in C, but it is unnecessary because C +does not have constructors or destructors. + @end table See also @ref{Namespace Association}. |