Sema: Definition of dllimport globals is not allowed

Upgrades the warning to an error and clarifies the message by treating the
definition as error instead of the attribute.

llvm-svn: 202300
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 229e2bb..eb2bc4f 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2055,6 +2055,8 @@
 def warn_attribute_invalid_on_definition : Warning<
   "'%0' attribute cannot be specified on a definition">,
   InGroup<IgnoredAttributes>;
+def err_attribute_dllimport_data_definition : Error<
+  "definition of dllimport data">;
 def err_attribute_weakref_not_static : Error<
   "weakref declaration must have internal linkage">;
 def err_attribute_weakref_not_global_context : Error<
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 266f668..601c161 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -8123,6 +8123,13 @@
       return;
   }
 
+  // dllimport cannot be used on variable definitions.
+  if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
+    Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition);
+    VDecl->setInvalidDecl();
+    return;
+  }
+
   if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
     // C99 6.7.8p5. C++ has no such restriction, but that is a defect.
     Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index d61d63a..2600a4f 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3793,15 +3793,6 @@
   if (D->hasAttr<DLLImportAttr>())
     return NULL;
 
-  if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
-    if (VD->hasDefinition()) {
-      // dllimport cannot be applied to definitions.
-      Diag(D->getLocation(), diag::warn_attribute_invalid_on_definition)
-        << "dllimport";
-      return NULL;
-    }
-  }
-
   return ::new (Context) DLLImportAttr(Range, Context, AttrSpellingListIndex);
 }
 
diff --git a/clang/test/Sema/dllexport.c b/clang/test/Sema/dllexport.c
index fb209e1..eb39fbe 100644
--- a/clang/test/Sema/dllexport.c
+++ b/clang/test/Sema/dllexport.c
@@ -85,8 +85,8 @@
 __attribute__((dllimport, dllexport))       int PrecedenceGlobal1A; // expected-warning{{'dllimport' attribute ignored}}
 __declspec(dllimport) __declspec(dllexport) int PrecedenceGlobal1B; // expected-warning{{'dllimport' attribute ignored}}
 
-__attribute__((dllexport, dllimport))       int PrecedenceGlobal2A; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
-__declspec(dllexport) __declspec(dllimport) int PrecedenceGlobal2B; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__attribute__((dllexport, dllimport))       int PrecedenceGlobal2A; // expected-warning{{'dllimport' attribute ignored}}
+__declspec(dllexport) __declspec(dllimport) int PrecedenceGlobal2B; // expected-warning{{'dllimport' attribute ignored}}
 
 __declspec(dllexport) extern int PrecedenceExternGlobalRedecl1;
 __declspec(dllimport) extern int PrecedenceExternGlobalRedecl1; // expected-warning{{'dllimport' attribute ignored}}
@@ -95,7 +95,7 @@
 __declspec(dllexport) extern int PrecedenceExternGlobalRedecl2;
 
 __declspec(dllexport) extern int PrecedenceGlobalRedecl1;
-__declspec(dllimport)        int PrecedenceGlobalRedecl1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__declspec(dllimport)        int PrecedenceGlobalRedecl1; // expected-warning{{'dllimport' attribute ignored}}
 
 __declspec(dllimport) extern int PrecedenceGlobalRedecl2; // expected-warning{{'dllimport' attribute ignored}}
 __declspec(dllexport)        int PrecedenceGlobalRedecl2;
diff --git a/clang/test/Sema/dllimport.c b/clang/test/Sema/dllimport.c
index ee1ad88..615f8f7 100644
--- a/clang/test/Sema/dllimport.c
+++ b/clang/test/Sema/dllimport.c
@@ -20,16 +20,17 @@
 // Import declaration.
 __declspec(dllimport) extern int ExternGlobalDecl;
 
-// dllimport implies a declaration. FIXME: This should not warn.
-__declspec(dllimport) int GlobalDecl; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+// dllimport implies a declaration.
+__declspec(dllimport) int GlobalDecl;
 
 // Not allowed on definitions.
-__declspec(dllimport) int GlobalInit1 = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
-int __declspec(dllimport) GlobalInit2 = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__declspec(dllimport) extern int ExternGlobalInit = 1; // expected-error{{definition of dllimport data}}
+__declspec(dllimport) int GlobalInit1 = 1; // expected-error{{definition of dllimport data}}
+int __declspec(dllimport) GlobalInit2 = 1; // expected-error{{definition of dllimport data}}
 
 // Declare, then reject definition.
 __declspec(dllimport) extern int ExternGlobalDeclInit;
-int ExternGlobalDeclInit = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+int ExternGlobalDeclInit = 1; // expected-error{{definition of dllimport data}}
 
 // Redeclarations
 __declspec(dllimport) extern int GlobalRedecl1;
@@ -37,7 +38,10 @@
 
 // Import in local scope.
 void functionScope() {
+  __declspec(dllimport)        int LocalVarDecl;
+  __declspec(dllimport)        int LocalVarDef = 1; // expected-error{{definition of dllimport data}}
   __declspec(dllimport) extern int ExternLocalVarDecl;
+  __declspec(dllimport) extern int ExternLocalVarDef = 1; // expected-error{{definition of dllimport data}}
 }
 
 
diff --git a/clang/test/SemaCXX/dllexport.cpp b/clang/test/SemaCXX/dllexport.cpp
index 114ebd0..6476383 100644
--- a/clang/test/SemaCXX/dllexport.cpp
+++ b/clang/test/SemaCXX/dllexport.cpp
@@ -161,8 +161,8 @@
 __attribute__((dllimport, dllexport))       int PrecedenceGlobal1A; // expected-warning{{'dllimport' attribute ignored}}
 __declspec(dllimport) __declspec(dllexport) int PrecedenceGlobal1B; // expected-warning{{'dllimport' attribute ignored}}
 
-__attribute__((dllexport, dllimport))       int PrecedenceGlobal2A; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
-__declspec(dllexport) __declspec(dllimport) int PrecedenceGlobal2B; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__attribute__((dllexport, dllimport))       int PrecedenceGlobal2A; // expected-warning{{'dllimport' attribute ignored}}
+__declspec(dllexport) __declspec(dllimport) int PrecedenceGlobal2B; // expected-warning{{'dllimport' attribute ignored}}
 
 __declspec(dllexport) extern int PrecedenceExternGlobalRedecl1;
 __declspec(dllimport) extern int PrecedenceExternGlobalRedecl1; // expected-warning{{'dllimport' attribute ignored}}
@@ -171,7 +171,7 @@
 __declspec(dllexport) extern int PrecedenceExternGlobalRedecl2;
 
 __declspec(dllexport) extern int PrecedenceGlobalRedecl1;
-__declspec(dllimport)        int PrecedenceGlobalRedecl1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__declspec(dllimport)        int PrecedenceGlobalRedecl1; // expected-warning{{'dllimport' attribute ignored}}
 
 __declspec(dllimport) extern int PrecedenceGlobalRedecl2; // expected-warning{{'dllimport' attribute ignored}}
 __declspec(dllexport)        int PrecedenceGlobalRedecl2;
diff --git a/clang/test/SemaCXX/dllimport.cpp b/clang/test/SemaCXX/dllimport.cpp
index d04a4b9..4a3ee20 100644
--- a/clang/test/SemaCXX/dllimport.cpp
+++ b/clang/test/SemaCXX/dllimport.cpp
@@ -32,16 +32,17 @@
 // Import declaration.
 __declspec(dllimport) extern int ExternGlobalDecl;
 
-// dllimport implies a declaration. FIXME: This should not warn.
-__declspec(dllimport) int GlobalDecl; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+// dllimport implies a declaration.
+__declspec(dllimport) int GlobalDecl;
 
 // Not allowed on definitions.
-__declspec(dllimport) int GlobalInit1 = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
-int __declspec(dllimport) GlobalInit2 = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+__declspec(dllimport) extern int ExternGlobalInit = 1; // expected-error{{definition of dllimport data}}
+__declspec(dllimport) int GlobalInit1 = 1; // expected-error{{definition of dllimport data}}
+int __declspec(dllimport) GlobalInit2 = 1; // expected-error{{definition of dllimport data}}
 
 // Declare, then reject definition.
 __declspec(dllimport) extern int ExternGlobalDeclInit;
-int ExternGlobalDeclInit = 1; // expected-warning{{'dllimport' attribute cannot be specified on a definition}}
+int ExternGlobalDeclInit = 1; // expected-error{{definition of dllimport data}}
 
 // Redeclarations
 __declspec(dllimport) extern int GlobalRedecl1;
@@ -49,7 +50,10 @@
 
 // Import in local scope.
 void functionScope() {
+  __declspec(dllimport)        int LocalVarDecl;
+  __declspec(dllimport)        int LocalVarDef = 1; // expected-error{{definition of dllimport data}}
   __declspec(dllimport) extern int ExternLocalVarDecl;
+  __declspec(dllimport) extern int ExternLocalVarDef = 1; // expected-error{{definition of dllimport data}}
 }