Changes in designated-initializers.cpp

5030928d - [c++20] Implement semantic restrictions for C++20 designated

Fri, 30 Aug 2019 22:52:55 +0000

[c++20] Implement semantic restrictions for C++20 designatedinitializers.This has some interesting interactions with our existing extensions tosupport C99 designated initializers as an extension in C++. Those areresolved as follows: * We continue to permit the full breadth of C99 designated initializers in C++, with the exception that we disallow a partial overwrite of an initializer with a non-trivially-destructible type. (Full overwrite is OK, because we won't run the first initializer at all.) * The C99 extensions are disallowed in SFINAE contexts and during overload resolution, where they could change the meaning of valid programs. * C++20 disallows reordering of initializers. We only check for that for the simple cases that the C++20 rules permit (designators of the form '.field_name =' and continue to allow reordering in other cases). It would be nice to improve this behavior in future. * All C99 designated initializer extensions produce a warning by default in C++20 mode. People are going to learn the C++ rules based on what Clang diagnoses, so it's important we diagnose these properly by default. * In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and so still diagnose C99 extensions as described above. We continue to accept designated C++20-compatible initializers in C++ <= 17 silently by default (but naturally still reject under -pedantic-errors).This is not a complete implementation of P0329R4. In particular, thatpaper introduces new non-C99-compatible syntax { .field { init } }, andwe do not support that yet.This is based on a previous patch by Don Hinton, though I've madesubstantial changes when addressing the above interactions.Differential Revision: https://reviews.llvm.org/D59754llvm-svn: 370544 List of files: /llvm-project-15.0.7/clang/test/SemaCXX/designated-initializers.cpp

cd839ccf - Fix silent wrong-code bugs and crashes with designated initialization.

Thu, 29 Aug 2019 22:49:34 +0000

Fix silent wrong-code bugs and crashes with designated initialization.We failed to correctly handle the 'holes' left behind by designatedinitializers in VerifyOnly mode. This would result in us thinking that adesignated initialization would be valid, only to find that it is notactually valid when we come to build it. In a +Asserts build, that wouldassert, and in a -Asserts build, that would silently lose some part ofthe initialization or crash.With this change, when an InitListExpr contains any designators, we nowalways build a structured list so that we can track the locations of the'holes' that we need to go back and fill in.We could in principle do better: we only need the structured form ifthere is a designator that jumps backwards (and can otherwise check forthe holes as we progress through the initializer list), but dealing withthat turns out to be rather complicated, so it's not done as part ofthis patch.llvm-svn: 370419 List of files: /llvm-project-15.0.7/clang/test/SemaCXX/designated-initializers.cpp

2383aad5 - [SemaCXX] add -Woverride-init alias to -Winitializer-overrides

Thu, 10 Jan 2019 19:12:39 +0000

[SemaCXX] add -Woverride-init alias to -Winitializer-overridesSummary:https://bugs.llvm.org/show_bug.cgi?id=40251https://github.com/ClangBuiltLinux/linux/issues/307Reviewers: rsmithReviewed By: rsmithSubscribers: cfe-commits, nathanchance, srhinesDifferential Revision: https://reviews.llvm.org/D56522llvm-svn: 350877 List of files: /llvm-project-15.0.7/clang/test/SemaCXX/designated-initializers.cpp

cb642b91 - [Sema][TreeTransform] Re-create DesignatedInitExpr when a field designator

Mon, 24 Oct 2016 09:33:32 +0000

[Sema][TreeTransform] Re-create DesignatedInitExpr when a field designatorhas no field declaration.This commit fixes an invalid Winitializer-overrides warning that's shownwhen analyzing a second (or any after the first) instantiation of a designatedinitializer. This invalid warning is fixed by making sure that aDesignatedInitExpr is rebuilt by the tree transformer when it has a fielddesignator whose FieldDecl* hasn't been yet initialized. This ensures that adifferent DesignatedInitExpr is processed by Sema for every instantiation, andthus the invalid warning is avoided.rdar://28768441Differential Revision: https://reviews.llvm.org/D25777llvm-svn: 284959 List of files: /llvm-project-15.0.7/clang/test/SemaCXX/designated-initializers.cpp