Variables marked as "extern" can actually have internal linkage if
there is a previous declaration marked "static". This fixes PR3645.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67336 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 99ea707..7c80fa5 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -832,9 +832,20 @@
Diag(Old->getLocation(), diag::note_previous_definition);
return true;
}
- // C99 6.2.2p4: Check if we have a non-static decl followed by a static.
- if (New->getStorageClass() != VarDecl::Static &&
- Old->getStorageClass() == VarDecl::Static) {
+ // C99 6.2.2p4:
+ // For an identifier declared with the storage-class specifier
+ // extern in a scope in which a prior declaration of that
+ // identifier is visible,23) if the prior declaration specifies
+ // internal or external linkage, the linkage of the identifier at
+ // the later declaration is the same as the linkage specified at
+ // the prior declaration. If no prior declaration is visible, or
+ // if the prior declaration specifies no linkage, then the
+ // identifier has external linkage.
+ if ((New->hasExternalStorage() || New->getStorageClass() == VarDecl::None) &&
+ Old->hasLinkage())
+ /* Okay */;
+ else if (New->getStorageClass() != VarDecl::Static &&
+ Old->getStorageClass() == VarDecl::Static) {
Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
Diag(Old->getLocation(), diag::note_previous_definition);
return true;