[PATCH] D120824: [clang][ASTImporter] Fix a bug when importing CXXDefaultInitExpr.

[Balázs Kéri via Phabricator via cfe-commits]

balazske added a comment.

In D120824#3369407 <https://reviews.llvm.org/D120824#3369407>, @martong wrote:

> So, my understanding is that the issue stems from the fact that `hasInClassInitializer()` gave inconsistent results with `getInClassInitializer()` for previously imported nodes.

Not really the API is the problem. The real problem was that to create a `CXXDefaultInitExpr` the field should have a "in-class initializer". `CXXDefaultInitExpr` has a pointer to the field that is initialized at that place. The field has an "in-class initializer", this is the used expression to initialize the field (`CXXDefaultInitExpr` is a separate object that is replicated for every initialization in constructors and initializer-list). The in-class initializer expression is not always stored in the AST, in the `ToTU` it is missing initially. The field has the flag set that it contains in-class initializer but the actual expression is not set yet (probably because the code parser works this way). This expression should be imported before a `CXXDefaultInitExpr` can be created.

The other code change (at lines 3650-60) is needed because `setInClassInitializer` can be called only if the value is not set already, otherwise it will assert.



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Comment at: clang/unittests/AST/ASTImporterTest.cpp:536-547
+TEST_P(ImportExpr, ImportCXXDefaultInitExpr) {
+  MatchVerifier<Decl> Verifier;
+  testImport("class declToImport { int DefInit = 5; }; declToImport X;",
+             Lang_CXX11, "", Lang_CXX11, Verifier,
+             cxxRecordDecl(hasDescendant(cxxConstructorDecl(
+                 hasAnyConstructorInitializer(cxxCtorInitializer(
+                     withInitializer(cxxDefaultInitExpr())))))));
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martong wrote:
> So these tests failed with the baseline?
This test was added only because there was no test for `CXXDefaultInitExpr`. Probably this test does not fail without the fix. The failing test is only the added lit test.


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