[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->getExpr()->getExprLoc(), 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

@@ -226,7 +226,8 @@ class BoolArgument<string name, bit opt = 0, bit fake = 0> : Argument<name, opt,
 class IdentifierArgument<string name, bit opt = 0> : Argument<name, opt>;
 class IntArgument<string name, bit opt = 0> : Argument<name, opt>;
 class StringArgument<string name, bit opt = 0> : Argument<name, opt>;
-class ExprArgument<string name, bit opt = 0> : Argument<name, opt>;
+class ExprArgument<string name, bit opt = 0, bit fake = 0> : Argument<name, opt,
+                                                                      fake>;
 class DeclArgument<DeclNode kind, string name, bit opt = 0, bit fake = 0>
     : Argument<name, opt, fake> {
   DeclNode Kind = kind;
@@ -1351,7 +1352,8 @@ def OSConsumesThis : InheritableAttr {
 
 def Cleanup : InheritableAttr {
   let Spellings = [GCC<"cleanup">];
-  let Args = [DeclArgument<Function, "FunctionDecl">];
+  let Args = [DeclArgument<Function, "FunctionDecl">,
+              ExprArgument<"Expr", /*opt=*/0, /*fake=*/1>];
   let Subjects = SubjectList<[LocalVar]>;
   let Documentation = [CleanupDocs];
 }

clang/lib/Sema/SemaDeclAttr.cpp

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

clang/test/AST/ast-dump-attr-json.cpp

@@ -149,7 +149,37 @@ __thread __attribute__ ((tls_model ("local-exec"))) int tls_model_var;
 // CHECK-NEXT:     "type": {
 // CHECK-NEXT:      "qualType": "void (int *)"
 // CHECK-NEXT:     }
-// CHECK-NEXT:    }
+// CHECK-NEXT:    },
+// CHECK-NEXT:    "inner": [
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "id": "0x{{.*}}",
+// CHECK-NEXT:       "kind": "DeclRefExpr",
+// CHECK-NEXT:       "range": {
+// CHECK-NEXT:         "begin": {
+// CHECK-NEXT:           "offset": 242,
+// CHECK-NEXT:           "col": 26,
+// CHECK-NEXT:           "tokLen": 16
+// CHECK-NEXT:         },
+// CHECK-NEXT:         "end": {
+// CHECK-NEXT:           "offset": 242,
+// CHECK-NEXT:           "col": 26,
+// CHECK-NEXT:           "tokLen": 16
+// CHECK-NEXT:         }
+// CHECK-NEXT:       },
+// CHECK-NEXT:       "type": {
+// CHECK-NEXT:         "qualType": "void (int *)"
+// CHECK-NEXT:       },
+// CHECK-NEXT:       "valueCategory": "lvalue",
+// CHECK-NEXT:       "referencedDecl": {
+// CHECK-NEXT:         "id": "0x{{.*}}",
+// CHECK-NEXT:         "kind": "FunctionDecl",
+// CHECK-NEXT:         "name": "cleanup_function",
+// CHECK-NEXT:         "type": {
+// CHECK-NEXT:           "qualType": "void (int *)"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       }
+// CHECK-NEXT:     }
+// CHECK-NEXT:    ]
 // CHECK-NEXT:   }
 // CHECK-NEXT:  ]
 // CHECK-NEXT: }