diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 99c9685..547ee2d 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -4942,8 +4942,15 @@ be useful to facilitate the conversion to @code{nullptr} in C++11. @opindex Wsubobject-linkage @opindex Wno-subobject-linkage Warn if a class type has a base or a field whose type uses the anonymous -namespace or depends on a type with no linkage. This warning is -enabled by default. +namespace or depends on a type with no linkage. If a type A depends on +a type B with no or internal linkage, defining it in multiple +translation units would be an ODR violation because the meaning of B +is different in each translation unit. If A only appears in a single +translation unit, the best way to silence the warning is to give it +internal linkage by putting it in an anonymous namespace as well. The +compiler doesn't give this warning for types defined in the main .C +file, as those are unlikely to have multiple definitions. +@option{-Wsubobject-linkage} is enabled by default. @item -Wdate-time @opindex Wdate-time |