[Clang] Fix cleanup attribute by delaying type checks after the type is deduced

clang/docs/ReleaseNotes.rst

@@ -447,6 +447,7 @@ Bug Fixes to Attribute Support
 - Using ``[[gnu::cleanup(some_func)]]`` where some_func is annotated with
   ``[[gnu::error("some error")]]`` now correctly triggers an error. (#GH146520)
 - Fix a crash when the function name is empty in the `swift_name` attribute. (#GH157075)
+- Fix ``cleanup`` attribute by delaying type checks after the type is deduced. (#GH129631)
 
 Bug Fixes to C++ Support
 ^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/Sema/Sema.h

@@ -4465,6 +4465,10 @@ class Sema final : public SemaBase {
       NamedDecl *New, Decl *Old,
       AvailabilityMergeKind AMK = AvailabilityMergeKind::Redeclaration);
 
+  /// CheckAttributesOnDeducedType - Calls Sema functions for attributes that
+  /// requires the type to be deduced.
+  void CheckAttributesOnDeducedType(Expr *E, Decl *D);
+
   /// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the
   /// same name and scope as a previous declaration 'Old'.  Figure out
   /// how to resolve this situation, merging decls or emitting
@@ -15483,6 +15487,8 @@ class Sema final : public SemaBase {
   std::optional<FunctionEffectMode>
   ActOnEffectExpression(Expr *CondExpr, StringRef AttributeName);
 
+  void ActOnCleanupAttr(Expr *E, Decl *D, const Attr *A);
+
 private:
   /// The implementation of RequireCompleteType
   bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,

clang/lib/Sema/SemaDecl.cpp

@@ -3354,6 +3354,21 @@ void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
   if (!foundAny) New->dropAttrs();
 }
 
+void Sema::CheckAttributesOnDeducedType(Expr *E, Decl *D) {
+  if (!D->hasAttrs())
+    return;
+
+  for (const Attr *A : D->getAttrs()) {
+    switch (A->getKind()) {
+    case attr::Cleanup:
+      ActOnCleanupAttr(E, D, A);
+      break;
+    default:
+      continue;
+    }
+  }
+}
+
 // Returns the number of added attributes.
 template <class T>
 static unsigned propagateAttribute(ParmVarDecl *To, const ParmVarDecl *From,
@@ -13797,6 +13812,8 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
       return;
   }
 
+  this->CheckAttributesOnDeducedType(Init, RealDecl);
+
   // dllimport cannot be used on variable definitions.
   if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
     Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition);
@@ -14587,6 +14604,7 @@ void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
         Var->setInit(RecoveryExpr.get());
     }
 
+    this->CheckAttributesOnDeducedType(Init.get(), RealDecl);
     CheckCompleteVariableDeclaration(Var);
   }
 }

clang/lib/Sema/SemaDeclAttr.cpp

@@ -3511,16 +3511,6 @@ static void handleCleanupAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     return;
   }
 
-  // We're currently more strict than GCC about what function types we accept.
-  // If this ever proves to be a problem it should be easy to fix.
-  QualType Ty = S.Context.getPointerType(cast<VarDecl>(D)->getType());
-  QualType ParamTy = FD->getParamDecl(0)->getType();
-  if (!S.IsAssignConvertCompatible(S.CheckAssignmentConstraints(
-          FD->getParamDecl(0)->getLocation(), ParamTy, Ty))) {
-    S.Diag(Loc, diag::err_attribute_cleanup_func_arg_incompatible_type)
-      << NI.getName() << ParamTy << Ty;
-    return;
-  }
   VarDecl *VD = cast<VarDecl>(D);
   // Create a reference to the variable declaration. This is a fake/dummy
   // reference.
@@ -8291,3 +8281,24 @@ void Sema::redelayDiagnostics(DelayedDiagnosticPool &pool) {
   assert(curPool && "re-emitting in undelayed context not supported");
   curPool->steal(pool);
 }
+
+void Sema::ActOnCleanupAttr(Expr *E, Decl *D, const Attr *A) {
+  // Obtains the FunctionDecl that was found when handling the attribute
+  // earlier.
+  CleanupAttr *Attr = D->getAttr<CleanupAttr>();
+  FunctionDecl *FD = Attr->getFunctionDecl();
+  DeclarationNameInfo NI = FD->getNameInfo();
+
+  // We're currently more strict than GCC about what function types we accept.
+  // If this ever proves to be a problem it should be easy to fix.
+  QualType Ty = this->Context.getPointerType(cast<VarDecl>(D)->getType());
+  QualType ParamTy = FD->getParamDecl(0)->getType();
+  if (!this->IsAssignConvertCompatible(this->CheckAssignmentConstraints(
+          FD->getParamDecl(0)->getLocation(), ParamTy, Ty))) {
+    this->Diag(Attr->getArgLoc(),
+               diag::err_attribute_cleanup_func_arg_incompatible_type)
+        << NI.getName() << ParamTy << Ty;
+    D->dropAttr<CleanupAttr>();
+    return;
+  }
+}

clang/test/Sema/type-dependent-attrs.c

@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -std=c23 -fsyntax-only -verify %s
+
+int open() { return 0; }
+void close(typeof(open()) *) {}
+
+void cleanup_attr() {
+  int fd_int [[gnu::cleanup(close)]] = open();
+  auto fd_auto [[gnu::cleanup(close)]] = open();
+  float fd_invalid [[gnu::cleanup(close)]] = open(); // expected-error {{'cleanup' function 'close' parameter has type 'typeof (open()) *' (aka 'int *') which is incompatible with type 'float *'}}
+}