<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/68775>68775</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang][ASTImporter] infinite recursion on lambda with deduced return type from struct declared inside
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          danix800
      </td>
    </tr>
</table>

<pre>
    `ASTNodeImporter::VisitFunctionDecl` considered about infinite recursion on function with deduced return type from struct declared inside function body, but it's not general enough on the following code:
```c
void foo() {
   (void) []() {
     struct X {};
     return X();
   };
}
```
The return type of this lambda is not declared as `auto` so infinite recursion still occurs whem imported:
```c
TEST_P(ASTImporterOptionSpecificTestBase, LambdaReturnWithStructInside) {
  Decl *From, *To;
  std::tie(From, To) = getImportedDecl(
      R"(
      void foo() {
        (void) []() {
          struct X {};
          return X();
        };
 }
      )",
      Lang_CXX11, "", Lang_CXX11, "foo");
  auto *ToLambda = FirstDeclMatcher<LambdaExpr>().match(To, lambdaExpr());
 EXPECT_TRUE(ToLambda);
}
```
</pre>
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