tree dc03f21bd2fd89c3f94984cc3ee9d1713dfcea4e
parent 1c860d5640e8eebb11a5d515a761242b66761b0b
author Argyrios Kyrtzidis <akyrtzi@gmail.com> 1303242670 +0000
committer Argyrios Kyrtzidis <akyrtzi@gmail.com> 1303242670 +0000

We regard a function as 'unused' from the codegen perspective, so our warnings diverge from
gcc's unused warnings which don't get emitted if the function is referenced even in an unevaluated context
(e.g. in templates, sizeof, etc.). Also, saying that a function is 'unused' because it won't get codegen'ed
is somewhat misleading.

- Don't emit 'unused' warnings for functions that are referenced in any part of the user's code.
- A warning that an internal function/variable won't get emitted is useful though, so introduce
  -Wunneeded-internal-declaration which will warn if a function/variable with internal linkage is not
  "needed" ('used' from the codegen perspective), e.g:

  static void foo() { }

  template <int>
  void bar() {
    foo();
  }

test.cpp:1:13: warning: function 'foo' is not needed and will not be emitted
static void foo() { }
            ^

Addresses rdar://8733476.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129794 91177308-0d34-0410-b5e6-96231b3b80d8