In the source
static void f();
static void f();
template<typename T>
static void g() {
f();
}
static void f() {
}
void h() {
g<int>();
}
the call to f refers to the second decl, but it is only marked used at the end
of the translation unit during instantiation, after the third f decl has been
linked in.
With this patch we mark all subsequent decls used, so that it is easy to check
if a symbol is used or not.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171888
91177308-0d34-0410-b5e6-
96231b3b80d8
/// \brief Used to prune the decls of Sema's UnusedFileScopedDecls vector.
static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
- // Template instantiation can happen at the end of the translation unit
- // and it sets the canonical (first) decl to used. Normal uses set the last
- // decl at the time to used and subsequent decl inherit the flag. The net
- // result is that we need to check both ends of the decl chain.
- if (D->isUsed() || D->getMostRecentDecl()->isUsed())
+ if (D->getMostRecentDecl()->isUsed())
return true;
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
if (old.isInvalid()) old = Loc;
}
- Func->setUsed(true);
+ // Normally the must current decl is marked used while processing the use and
+ // any subsequent decls are marked used by decl merging. This fails with
+ // template instantiation since marking can happen at the end of the file
+ // and, because of the two phase lookup, this function is called with at
+ // decl in the middle of a decl chain. We loop to maintain the invariant
+ // that once a decl is used, all decls after it are also used.
+ for (FunctionDecl *F = Func->getMostRecentDecl();;) {
+ F->setUsed(true);
+ if (F == Func)
+ break;
+ F = F->getPreviousDecl();
+ }
}
static void
g<int>();
}
}
+
+namespace test4 {
+ static void f();
+ static void f();
+ template<typename T>
+ static void g() {
+ f();
+ }
+ static void f() {
+ }
+ void h() {
+ g<int>();
+ }
+}