[PATCH] D123649: Allow flexible array initialization in C++.

[Erich Keane via Phabricator via cfe-commits]

erichkeane added inline comments.


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Comment at: clang/lib/CodeGen/CGDecl.cpp:346
+    else if (!D.getFlexibleArrayInitChars(getContext()).isZero())
+      CGM.ErrorUnsupported(D.getInit(), "flexible array init");
     else if (HaveInsertPoint()) {
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Can you write a test for this with a 'fixme'?  I don't see a reason why we shouldn't support this eventually.


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Comment at: clang/lib/CodeGen/CodeGenModule.cpp:4617
       if (getLangOpts().CPlusPlus) {
+        if (!InitDecl->getFlexibleArrayInitChars(getContext()).isZero())
+          ErrorUnsupported(D, "flexible array initializer");
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Same comment here.


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Comment at: clang/test/SemaCXX/constant-expression-cxx11.cpp:2388
+  // evaluation. Make sure we emit a sane error message, for now.
+  constexpr A c = {1, 2, 3}; // expected-warning {{flexible array initialization is a GNU extension}}
+  static_assert(c.arr[0] == 1, ""); // expected-error {{constant expression}} expected-note {{array member without known bound}}
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I would expect this to be an error, not the static-assert.  The constexpr variable means 'initializable as a constant expression'.  

I'm guessing the problem is ACTUALLY that we support constexpr init, but not the operator[].  I think I'd like to have us have the initialization fail here, since it isn't otherwise usable.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D123649/new/

https://reviews.llvm.org/D123649