Index: lib/MC/MCParser/ELFAsmParser.cpp
===================================================================
--- lib/MC/MCParser/ELFAsmParser.cpp
+++ lib/MC/MCParser/ELFAsmParser.cpp
@@ -427,13 +427,13 @@
     GroupName = getTok().getString();
     Lex();
   } else if (getParser().parseIdentifier(GroupName)) {
-    return true;
+    return TokError("invalid group name");
   }
   if (L.is(AsmToken::Comma)) {
     Lex();
     StringRef Linkage;
     if (getParser().parseIdentifier(Linkage))
-      return true;
+      return TokError("invalid linkage");
     if (Linkage != "comdat")
       return TokError("Linkage must be 'comdat'");
   }
Index: test/MC/ELF/comdat-declaration-errors.s
===================================================================
--- test/MC/ELF/comdat-declaration-errors.s
+++ test/MC/ELF/comdat-declaration-errors.s
@@ -0,0 +1,14 @@
+// RUN: not llvm-mc -triple x86_64-pc-linux-gnu %s \
+// RUN:   -filetype=obj -o %t.o 2>&1 | FileCheck %s
+
+// Check we error out on incorrect COMDATs declarations
+// and not just silently ingnore them.
+
+// CHECK:      error: invalid group name
+// CHECK-NEXT: .section .foo,"G",@progbits,-abc,comdat
+
+// CHECK:      error: invalid linkage
+// CHECK-NEXT: .section .bar,"G",@progbits,abc,-comdat
+
+.section .foo,"G",@progbits,-abc,comdat
+.section .bar,"G",@progbits,abc,-comdat