[PATCH] Add support for __declspec(thread) under -fms-extensions

[Richard Smith]

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Comment at: include/clang/Basic/Attr.td:1671
@@ +1670,3 @@
+  let LangOpts = [MicrosoftExt];
+  let Documentation = [Undocumented];
+  let Subjects = SubjectList<[Var]>;
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ITYM `ThreadDocs`?

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Comment at: include/clang/Basic/AttrDocs.td:58
@@ +57,3 @@
+storage.  It is available under the ``-fms-extensions`` flag for MSVC
+compatiblity.  Documentation for the Visual C++ attribute is available on MSDN_.
+
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Typo 'compatiblity'

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Comment at: lib/Sema/SemaDecl.cpp:8928-8934
@@ +8927,9 @@
+    const CXXRecordDecl *RD = var->getType()->getAsCXXRecordDecl();
+    if (RD && RD->hasNonTrivialDefaultConstructor()) {
+      // MSVC doesn't allow thread local variables with any constructors, but we
+      // only look for the default constructor.
+      Diag(var->getLocation(), diag::err_thread_nontrivial_ctor);
+      if (getLangOpts().CPlusPlus11)
+        Diag(var->getLocation(), diag::note_use_thread_local);
+    }
+  }
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This seems really weird. We're already checking for non-constant initialization; do you have any idea what this check is for? You can check for 'any constructor' using `CXXRecordDecl::hasUserDeclaredConstructor`.

http://reviews.llvm.org/D3551