================
@@ -1980,6 +1981,23 @@ static void handleWeakRefAttr(Sema &S, Decl *D, const
ParsedAttr &AL) {
D->addAttr(::new (S.Context) WeakRefAttr(S.Context, AL));
}
+// Mark alias/ifunc target as used. For C++, we look up the demangled name
+// ignoring parameters. This should handle the majority of use cases while
+// leaveing false positives for namespace scope names and false negatives in
+// the presence of overloads.
+static void markUsedForAliasOrIfunc(Sema &S, Decl *D, const ParsedAttr &AL,
+ StringRef Str) {
+ char *Demangled = llvm::itaniumDemangle(Str, /*ParseParams=*/false);
+ if (Demangled)
+ Str = Demangled;
+ const DeclarationNameInfo target(&S.Context.Idents.get(Str), AL.getLoc());
+ LookupResult LR(S, target, Sema::LookupOrdinaryName);
+ if (S.LookupQualifiedName(LR, S.getCurLexicalContext()))
+ for (NamedDecl *ND : LR)
+ ND->markUsed(S.Context);
----------------
MaskRay wrote:
"alias" can target variables. "ifunc" has an existing diagnostic to reject
non-function targets.
```
% cat a.c
static int x;
extern void y() __attribute__((ifunc("x")));
% clang -c a.c
a.c:2:32: error: ifunc must point to a defined function
2 | extern void y() __attribute__((ifunc("x")));
| ^
1 error generated.
```
I am adding a template test:
```cpp
template <class T>
static void *f3(T) { return nullptr; }
static void *f3() { return nullptr; } // expected-warning{{unused function
'f3'}}
extern void g3() __attribute__((ifunc("_ZL2f3IiEPvT_")));
void *use3 = f3(0);
```
I think the current code does the right thing for templates.
https://github.com/llvm/llvm-project/pull/87130
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
