commit 606bd6dcc547cf2f9fd7387321db79419bf60041
author Hans Wennborg <hans@hanshq.net> Mon Nov 03 14:24:45 2014 +0000
committer Hans Wennborg <hans@hanshq.net> Mon Nov 03 14:24:45 2014 +0000
tree 2acc1255fba6da316a5ec54f4a502cd7ec669fab
parent 42bce8f69db28b6b39453ecfbf8da6fc45fb14bf

Don't dllimport inline functions when targeting MinGW (PR21366)

It turns out that MinGW never dllimports of exports inline functions.
This means that code compiled with Clang would fail to link with
MinGW-compiled libraries since we might try to import functions that
are not imported.

To fix this, make Clang never dllimport inline functions when targeting
MinGW.

llvm-svn: 221154

clang/lib/Sema/SemaDecl.cpp

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 734a01e..fe59811 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5185,6 +5185,14 @@
     S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute);
     OldDecl->dropAttr<DLLImportAttr>();
     NewDecl->dropAttr<DLLImportAttr>();
+  } else if (IsInline && OldImportAttr &&
+             !S.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+    // In MinGW, seeing a function declared inline drops the dllimport attribute.
+    OldDecl->dropAttr<DLLImportAttr>();
+    NewDecl->dropAttr<DLLImportAttr>();
+    S.Diag(NewDecl->getLocation(),
+           diag::warn_dllimport_dropped_from_inline_function)
+        << NewDecl << OldImportAttr;
   }
 }
 

clang/lib/Sema/SemaDeclAttr.cpp

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index f6a89d7..1b04e52 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3999,6 +3999,16 @@
     return;
   }
 
+  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    if (FD->isInlined() && A.getKind() == AttributeList::AT_DLLImport &&
+        !S.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+      // MinGW doesn't allow dllimport on inline functions.
+      S.Diag(A.getRange().getBegin(), diag::warn_attribute_ignored_on_inline)
+          << A.getName();
+      return;
+    }
+  }
+
   unsigned Index = A.getAttributeSpellingListIndex();
   Attr *NewAttr = A.getKind() == AttributeList::AT_DLLExport
                       ? (Attr *)S.mergeDLLExportAttr(D, A.getRange(), Index)

clang/lib/Sema/SemaDeclCXX.cpp

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index e717183..031edf1 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -4655,7 +4655,9 @@
     // Don't inherit dll attribute until the template is instantiated.
     return;
 
-  bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
+  // The class is either imported or exported.
+  const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
+  const bool ClassImported = !ClassExported;
 
   // Force declaration of implicit members so they can inherit the attribute.
   S.ForceDeclarationOfImplicitMembers(Class);
@@ -4674,15 +4676,22 @@
     if (!VD && !MD)
       continue;
 
-    // Don't process deleted methods.
-    if (MD && MD->isDeleted())
-      continue;
+    if (MD) {
+      // Don't process deleted methods.
+      if (MD->isDeleted())
+        continue;
 
-    if (MD && MD->isMoveAssignmentOperator() && !ClassExported &&
-        MD->isInlined()) {
-      // Current MSVC versions don't export the move assignment operators, so
-      // don't attempt to import them if we have a definition.
-      continue;
+      if (MD->isMoveAssignmentOperator() && ClassImported && MD->isInlined()) {
+        // Current MSVC versions don't export the move assignment operators, so
+        // don't attempt to import them if we have a definition.
+        continue;
+      }
+
+      if (MD->isInlined() && ClassImported &&
+          !S.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+        // MinGW does not import inline functions.
+        continue;
+      }
     }
 
     if (!getDLLAttr(Member)) {