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.
llvm-svn: 129794
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 673b718..41a0361 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -242,6 +242,18 @@
return false;
}
+bool Decl::isReferenced() const {
+ if (Referenced)
+ return true;
+
+ // Check redeclarations.
+ for (redecl_iterator I = redecls_begin(), E = redecls_end(); I != E; ++I)
+ if (I->Referenced)
+ return true;
+
+ return false;
+}
+
/// \brief Determine the availability of the given declaration based on
/// the target platform.
///