[PATCH] D23385: Implement __attribute__((require_constant_initialization)) for safe static initialization.

[Richard Smith via cfe-commits]

rsmith added inline comments.

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Comment at: include/clang/Basic/AttrDocs.td:858
@@ +857,3 @@
+  };
+  SAFE_STATIC T x = {42}; // OK.
+  SAFE_STATIC T y = 42; // error: variable does not have a constant initializer
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Sure, if that's a conscious design decision for the attribute.

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Comment at: include/clang/Basic/DiagnosticSemaKinds.td:6842
@@ +6841,3 @@
+
+def err_require_constant_init_failed : Error<
+  "variable does not have a constant initializer as required by the "
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A separate note pointed at the attribute would make it clearer how the attribute got involved (especially via the macro expansion backtrace).

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Comment at: lib/Sema/SemaDecl.cpp:10519-10520
@@ +10518,4 @@
+      auto *CE = dyn_cast<CXXConstructExpr>(Init);
+      bool DiagErr = (var->isInitKnownICE() || (CE && CE->getConstructor()->isConstexpr()))
+          ? !var->checkInitIsICE() : !checkConstInit();
+      if (DiagErr)
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In C++11 onwards, `checkInitIsICE` is the right thing to use in all cases. In C++98, `checkInitIsICE` is appropriate for globals of integral type; we do not have an implementation of strict constant expression checking for other types. Perhaps just documenting that (and maybe adding a FIXME here) is the best you can do for now, assuming you're not interested in implementing the C++98 rules.


https://reviews.llvm.org/D23385