[clang-tools-extra] [clang-tidy]: Add TagDecl only when it is a definition && Fix issue 6… (PR #67639)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

<details>
<summary>Changes</summary>

Fix issue 67529, [clang-tidy: modernize-use-using fails when type is implicitly forward declared](https://github.com/llvm/llvm-project/issues/67529)

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Full diff: https://github.com/llvm/llvm-project/pull/67639.diff


2 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp (+2-1) 
- (modified) clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp (+4) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
index 22dc9e21cab9d5a..e6293ed48bfddbb 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
@@ -61,7 +61,8 @@ void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
     // before the typedef will be the nested one (PR#50990). Therefore, we also
     // keep track of the parent declaration, so that we can look up the last
     // TagDecl that is a sibling of the typedef in the AST.
-    LastTagDeclRanges[ParentDecl] = MatchedTagDecl->getSourceRange();
+    if (MatchedTagDecl->isThisDeclarationADefinition())
+      LastTagDeclRanges[ParentDecl] = MatchedTagDecl->getSourceRange();
     return;
   }
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp
index f7db0af6434ac42..422abee11a71962 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp
@@ -321,3 +321,7 @@ typedef bool (*ISSUE_65055_2)(int);
 // CHECK-MESSAGES: :[[@LINE-2]]:1: warning: use 'using' instead of 'typedef'
 // CHECK-FIXES: {{^}}using ISSUE_65055_1 = void (*)(int);{{$}}
 // CHECK-FIXES: {{^}}using ISSUE_65055_2 = bool (*)(int);{{$}}
+
+typedef class ISSUE_67529_1 *ISSUE_67529;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using ISSUE_67529 = class ISSUE_67529_1 *;

``````````

</details>


https://github.com/llvm/llvm-project/pull/67639