<div dir="ltr">I suspect we'll need to do a little more than this: when we rebuild the redeclaration chain, we should probably propagate the complete type to later redeclarations in the same scope. Otherwise, if we import a module that has a complete type and one that has an incomplete type, the declaration found by name lookup might be the one with the incomplete type, possibly resulting in rejects-valid on code like this:<div><br></div><div>a.h:</div><div>extern int a[5];</div><div><br></div><div>b.h:</div><div>extern int a[];</div><div><br></div><div>x.cc:</div><div>#include "a.h"</div><div>#include "b.h"</div><div>int k = sizeof(a);</div><div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jan 22, 2016 at 11:03 AM, Yaron Keren via cfe-commits <span dir="ltr"><<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: yrnkrn<br>
Date: Fri Jan 22 13:03:27 2016<br>
New Revision: 258524<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=258524&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=258524&view=rev</a><br>
Log:<br>
Merge templated static member variables, fixes <a href="http://llvm.org/pr26179" rel="noreferrer" target="_blank">http://llvm.org/pr26179</a>.<br>
<br>
Patch by Vassil Vassilev!<br>
Reviewed by Richard Smith.<br>
<br>
<br>
Added:<br>
cfe/trunk/test/Modules/Inputs/PR26179/<br>
cfe/trunk/test/Modules/Inputs/PR26179/A.h<br>
cfe/trunk/test/Modules/Inputs/PR26179/B.h<br>
cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h<br>
cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap<br>
cfe/trunk/test/Modules/pr26179.cpp<br>
Modified:<br>
cfe/trunk/lib/Serialization/ASTReaderDecl.cpp<br>
<br>
Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=258524&r1=258523&r2=258524&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=258524&r1=258523&r2=258524&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)<br>
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Fri Jan 22 13:03:27 2016<br>
@@ -2595,8 +2595,24 @@ static bool isSameEntity(NamedDecl *X, N<br>
// Variables with the same type and linkage match.<br>
if (VarDecl *VarX = dyn_cast<VarDecl>(X)) {<br>
VarDecl *VarY = cast<VarDecl>(Y);<br>
- return (VarX->getLinkageInternal() == VarY->getLinkageInternal()) &&<br>
- VarX->getASTContext().hasSameType(VarX->getType(), VarY->getType());<br>
+ if (VarX->getLinkageInternal() == VarY->getLinkageInternal()) {<br>
+ ASTContext &C = VarX->getASTContext();<br>
+ if (C.hasSameType(VarX->getType(), VarY->getType()))<br>
+ return true;<br>
+<br>
+ // We can get decls with different types on the redecl chain. Eg.<br>
+ // template <typename T> struct S { static T Var[]; }; // #1<br>
+ // template <typename T> T S<T>::Var[sizeof(T)]; // #2<br>
+ // Only? happens when completing an incomplete array type. In this case<br>
+ // when comparing #1 and #2 we should go through their elements types.<br>
+ const ArrayType *VarXTy = C.getAsArrayType(VarX->getType());<br>
+ const ArrayType *VarYTy = C.getAsArrayType(VarY->getType());<br>
+ if (!VarXTy || !VarYTy)<br>
+ return false;<br>
+ if (VarXTy->isIncompleteArrayType() || VarYTy->isIncompleteArrayType())<br>
+ return C.hasSameType(VarXTy->getElementType(), VarYTy->getElementType());<br>
+ }<br>
+ return false;<br>
}<br>
<br>
// Namespaces with the same name and inlinedness match.<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/PR26179/A.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/A.h?rev=258524&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/A.h?rev=258524&view=auto</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/Inputs/PR26179/A.h (added)<br>
+++ cfe/trunk/test/Modules/Inputs/PR26179/A.h Fri Jan 22 13:03:27 2016<br>
@@ -0,0 +1,4 @@<br>
+#include "basic_string.h"<br>
+#include "B.h"<br>
+<br>
+int *p = a;<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/PR26179/B.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/B.h?rev=258524&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/B.h?rev=258524&view=auto</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/Inputs/PR26179/B.h (added)<br>
+++ cfe/trunk/test/Modules/Inputs/PR26179/B.h Fri Jan 22 13:03:27 2016<br>
@@ -0,0 +1,2 @@<br>
+#include "basic_string.h"<br>
+extern int a[5];<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h?rev=258524&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h?rev=258524&view=auto</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h (added)<br>
+++ cfe/trunk/test/Modules/Inputs/PR26179/basic_string.h Fri Jan 22 13:03:27 2016<br>
@@ -0,0 +1,14 @@<br>
+#ifndef _GLIBCXX_STRING<br>
+#define _GLIBCXX_STRING 1<br>
+<br>
+template<typename T><br>
+struct basic_string {<br>
+ static T _S_empty_rep_storage[];<br>
+};<br>
+<br>
+template<typename T><br>
+T basic_string<T>::_S_empty_rep_storage[sizeof(T)];<br>
+<br>
+extern int a[];<br>
+<br>
+#endif<br>
<br>
Added: cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap?rev=258524&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap?rev=258524&view=auto</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap (added)<br>
+++ cfe/trunk/test/Modules/Inputs/PR26179/module.modulemap Fri Jan 22 13:03:27 2016<br>
@@ -0,0 +1,9 @@<br>
+module A {<br>
+ header "A.h"<br>
+ export *<br>
+}<br>
+<br>
+module B {<br>
+ header "B.h"<br>
+ export *<br>
+}<br>
<br>
Added: cfe/trunk/test/Modules/pr26179.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/pr26179.cpp?rev=258524&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/pr26179.cpp?rev=258524&view=auto</a><br>
==============================================================================<br>
--- cfe/trunk/test/Modules/pr26179.cpp (added)<br>
+++ cfe/trunk/test/Modules/pr26179.cpp Fri Jan 22 13:03:27 2016<br>
@@ -0,0 +1,7 @@<br>
+// RUN: rm -rf %t<br>
+// RUN: %clang_cc1 -I%S/Inputs/PR26179 -verify %s<br>
+// RUN: %clang_cc1 -fmodules -fmodule-map-file=%S/Inputs/PR26179/module.modulemap -fmodules-cache-path=%t -I%S/Inputs/PR26179 -verify %s<br>
+<br>
+#include "A.h"<br>
+<br>
+// expected-no-diagnostics<br>
<br>
<br>
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</blockquote></div><br></div></div></div>