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

1 files changed, 3 insertions, 3 deletions

diff --git a/test/Sema/warn-unused-function.c b/test/Sema/warn-unused-function.c
index 5bbcf18a62..8f4cdcba88 100644
--- a/test/Sema/warn-unused-function.c
+++ b/test/Sema/warn-unused-function.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -Wunused-function -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wunused-function -Wunneeded-internal-declaration -verify %s
 // RUN: %clang_cc1 -fsyntax-only -verify -Wunused %s
 // RUN: %clang_cc1 -fsyntax-only -verify -Wall %s
 
@@ -6,7 +6,7 @@ void foo() {}
 static void f2() {} 
 static void f1() {f2();} // expected-warning{{unused}}
 
-static int f0() { return 17; } // expected-warning{{unused}}
+static int f0() { return 17; } // expected-warning{{not needed and will not be emitted}}
 int x = sizeof(f0());
 
 static void f3();
@@ -46,7 +46,7 @@ static void f12(void) { }  // expected-warning{{unused}}
 static void f12(void);
 
 // PR7923
-static void unused(void) { unused(); }  // expected-warning{{unused}}
+static void unused(void) { unused(); }  // expected-warning{{not needed and will not be emitted}}
 
 // rdar://8728293
 static void cleanupMalloc(char * const * const allocation) { }