[PATCH] D33841: [clang-tidy] redundant keyword check

[Daniel Kolozsvari via Phabricator via cfe-commits]

koldaniel marked an inline comment as done.
koldaniel added inline comments.


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Comment at: test/clang-tidy/readability-redundant-extern.cpp:37
+
+void another_file_scope(int _extern);
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aaron.ballman wrote:
> More tests that I figured out:
> ```
> namespace {
> extern void f(); // 'extern' is not redundant
> }
> 
> namespace a {
> namespace {
> namespace b {
> extern void f(); // 'extern' is not redundant
> }
> }
> }
> 
> // Note, the above are consequences of http://eel.is/c++draft/basic.link#6
> 
> #define FOO_EXTERN extern
> typedef int extern_int;
> 
> extern_int FOO_EXTERN foo(); // 'extern' is redundant, but hopefully we don't try to fixit this to be '_int FOO_EXTERN foo();'
> 
> // The above is a weird consequence of how specifiers are parsed in C and C++
> ```
In the first two examples extern is redundant:

"An unnamed namespace or a namespace declared directly or indirectly within an unnamed namespace has internal linkage. All other namespaces have external linkage."

Also, based on the examples in http://eel.is/c++draft/basic.link#8 , the extern keyword has no effect in case of unnamed namespaces. In case of 'C' linkage defined by an extern keyword the checker does not warn.



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https://reviews.llvm.org/D33841