2 files changed, 16 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 03a3e36b831..89185c89518 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2432,6 +2432,12 @@ CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
       EmitGlobalVarDefinition(D);
     }
 
+    // Emit section information for extern variables.
+    if (D->hasExternalStorage()) {
+      if (const SectionAttr *SA = D->getAttr<SectionAttr>())
+        GV->setSection(SA->getName());
+    }
+
     // Handle XCore specific ABI requirements.
     if (getTriple().getArch() == llvm::Triple::xcore &&
         D->getLanguageLinkage() == CLanguageLinkage &&
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 33f02c5b7f4..c99dbd944b0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2607,6 +2607,16 @@ void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
     }
   }
 
+  // This redeclaration adds a section attribute.
+  if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
+    if (auto *VD = dyn_cast<VarDecl>(New)) {
+      if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
+        Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
+        Diag(Old->getLocation(), diag::note_previous_declaration);
+      }
+    }
+  }
+
   if (!Old->hasAttrs())
     return;