[clang-include-cleaner] Make cleanup attr report expr location

Instead of reporting the location of the attribute, let's report
the location of the function reference that's passed to the cleanup
attribute as the first argument. This is required as the attribute
might be coming from a macro which means clang-include-cleaner skips
the use as it gets attributed to the header file declaringt the macro
and not to the main file.

To make this work, we have to add a fake argument to the CleanupAttr
constructor so we can pass in the original Expr alongside the function
declaration.

Fixes #140212

Author: DaanDeMeyer

clang-tools-extra/include-cleaner/lib/WalkAST.cpp

@@ -322,7 +322,7 @@ class ASTWalker : public RecursiveASTVisitor<ASTWalker> {
   }
 
   bool VisitCleanupAttr(CleanupAttr *attr) {
-    report(attr->getLocation(), attr->getFunctionDecl());
+    report(attr->getArgLoc(), attr->getFunctionDecl());
     return true;
   }
 

clang-tools-extra/include-cleaner/unittests/WalkASTTest.cpp

@@ -573,7 +573,7 @@ TEST(WalkAST, OperatorNewDelete) {
 
 TEST(WalkAST, CleanupAttr) {
   testWalk("void* $explicit^freep(void *p);",
-           "void foo() { __attribute__((^__cleanup__(freep))) char* x = 0; }");
+           "void foo() { __attribute__((__cleanup__(^freep))) char* x = 0; }");
 }
 
 } // namespace

clang/include/clang/Basic/Attr.td

@@ -1354,6 +1354,17 @@ def Cleanup : InheritableAttr {
   let Args = [DeclArgument<Function, "FunctionDecl">];
   let Subjects = SubjectList<[LocalVar]>;
   let Documentation = [CleanupDocs];
+  // FIXME: DeclArgument should be reworked to also store the
+  // Expr instead of adding attr specific hacks like the following.
+  // See the discussion in https://github.com/llvm/llvm-project/pull/14023.
+  let AdditionalMembers = [{
+private:
+    SourceLocation ArgLoc;
+
+public:
+    void setArgLoc(const SourceLocation &Loc) { ArgLoc = Loc; }
+    auto getArgLoc() const { return ArgLoc; }
+  }];
 }
 
 def CmseNSEntry : InheritableAttr, TargetSpecificAttr<TargetARM> {
@@ -4815,7 +4826,7 @@ def HLSLResourceBinding: InheritableAttr {
       void setImplicitBindingOrderID(uint32_t Value) {
         ImplicitBindingOrderID = Value;
       }
-      bool hasImplicitBindingOrderID() const { 
+      bool hasImplicitBindingOrderID() const {
         return ImplicitBindingOrderID.has_value();
       }
       uint32_t getImplicitBindingOrderID() const {

clang/lib/Sema/SemaDeclAttr.cpp

@@ -3620,7 +3620,9 @@ static void handleCleanupAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     return;
   }
 
-  D->addAttr(::new (S.Context) CleanupAttr(S.Context, AL, FD));
+  auto *attr = ::new (S.Context) CleanupAttr(S.Context, AL, FD);
+  attr->setArgLoc(E->getExprLoc());
+  D->addAttr(attr);
 }
 
 static void handleEnumExtensibilityAttr(Sema &S, Decl *D,