Index: include/lldb/Utility/ArchSpec.h
===================================================================
--- include/lldb/Utility/ArchSpec.h
+++ include/lldb/Utility/ArchSpec.h
@@ -376,20 +376,10 @@
     return !m_triple.getVendorName().empty();
   }
 
-  bool TripleVendorIsUnspecifiedUnknown() const {
-    return m_triple.getVendor() == llvm::Triple::UnknownVendor &&
-           m_triple.getVendorName().empty();
-  }
-
   bool TripleOSWasSpecified() const { return !m_triple.getOSName().empty(); }
 
   bool TripleEnvironmentWasSpecified() const {
-    return !m_triple.getEnvironmentName().empty();
-  }
-
-  bool TripleOSIsUnspecifiedUnknown() const {
-    return m_triple.getOS() == llvm::Triple::UnknownOS &&
-           m_triple.getOSName().empty();
+    return m_triple.hasEnvironment();
   }
 
   //------------------------------------------------------------------
Index: source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
===================================================================
--- source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
+++ source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
@@ -3309,7 +3309,7 @@
   }
 
   if (CalculateType() == eTypeCoreFile &&
-      m_arch_spec.TripleOSIsUnspecifiedUnknown()) {
+      !m_arch_spec.TripleOSWasSpecified()) {
     // Core files don't have section headers yet they have PT_NOTE program
     // headers that might shed more light on the architecture
     for (const elf::ELFProgramHeader &H : ProgramHeaders()) {
Index: source/Utility/ArchSpec.cpp
===================================================================
--- source/Utility/ArchSpec.cpp
+++ source/Utility/ArchSpec.cpp
@@ -889,10 +889,9 @@
 }
 
 void ArchSpec::MergeFrom(const ArchSpec &other) {
-  if (TripleVendorIsUnspecifiedUnknown() &&
-      !other.TripleVendorIsUnspecifiedUnknown())
+  if (!TripleVendorWasSpecified() && other.TripleVendorWasSpecified())
     GetTriple().setVendor(other.GetTriple().getVendor());
-  if (TripleOSIsUnspecifiedUnknown() && !other.TripleOSIsUnspecifiedUnknown())
+  if (!TripleOSWasSpecified() && other.TripleVendorWasSpecified())
     GetTriple().setOS(other.GetTriple().getOS());
   if (GetTriple().getArch() == llvm::Triple::UnknownArch) {
     GetTriple().setArch(other.GetTriple().getArch());
@@ -903,8 +902,8 @@
     if (other.GetCore() != eCore_uknownMach64)
       UpdateCore();
   }
-  if (GetTriple().getEnvironment() == llvm::Triple::UnknownEnvironment &&
-      !TripleVendorWasSpecified()) {
+  if (!TripleEnvironmentWasSpecified() &&
+      other.TripleEnvironmentWasSpecified() && !TripleVendorWasSpecified()) {
     if (other.TripleVendorWasSpecified())
       GetTriple().setEnvironment(other.GetTriple().getEnvironment());
   }
Index: unittests/Utility/ArchSpecTest.cpp
===================================================================
--- unittests/Utility/ArchSpecTest.cpp
+++ unittests/Utility/ArchSpecTest.cpp
@@ -232,3 +232,76 @@
   EXPECT_FALSE(ArchSpec());
   EXPECT_TRUE(ArchSpec("x86_64-pc-linux"));
 }
+
+TEST(ArchSpecTest, TripleComponentsWereSpecified) {
+  {
+    ArchSpec A("");
+    ArchSpec B("-");
+    ArchSpec C("--");
+    ArchSpec D("---");
+
+    ASSERT_FALSE(A.TripleVendorWasSpecified());
+    ASSERT_FALSE(A.TripleOSWasSpecified());
+    ASSERT_FALSE(A.TripleEnvironmentWasSpecified());
+
+    ASSERT_FALSE(B.TripleVendorWasSpecified());
+    ASSERT_FALSE(B.TripleOSWasSpecified());
+    ASSERT_FALSE(B.TripleEnvironmentWasSpecified());
+
+    ASSERT_FALSE(C.TripleVendorWasSpecified());
+    ASSERT_FALSE(C.TripleOSWasSpecified());
+    ASSERT_FALSE(C.TripleEnvironmentWasSpecified());
+
+    ASSERT_FALSE(D.TripleVendorWasSpecified());
+    ASSERT_FALSE(D.TripleOSWasSpecified());
+    ASSERT_FALSE(D.TripleEnvironmentWasSpecified());
+  }
+  {
+    // TODO: llvm::Triple::normalize treats the missing components from these
+    // triples as specified unknown components instead of unspecified
+    // components. We need to either change the behavior in llvm or work around
+    // this in lldb.
+    ArchSpec A("armv7");
+    ArchSpec B("armv7-");
+    ArchSpec C("armv7--");
+    ArchSpec D("armv7---");
+
+    ASSERT_FALSE(A.TripleVendorWasSpecified());
+    ASSERT_FALSE(A.TripleOSWasSpecified());
+    ASSERT_FALSE(A.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(B.TripleVendorWasSpecified());
+    ASSERT_FALSE(B.TripleOSWasSpecified());
+    ASSERT_FALSE(B.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(C.TripleVendorWasSpecified());
+    ASSERT_TRUE(C.TripleOSWasSpecified());
+    ASSERT_FALSE(C.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(D.TripleVendorWasSpecified());
+    ASSERT_TRUE(D.TripleOSWasSpecified());
+    ASSERT_TRUE(D.TripleEnvironmentWasSpecified());
+  }
+  {
+    ArchSpec A("x86_64-unknown");
+    ArchSpec B("powerpc-unknown-linux");
+    ArchSpec C("i386-pc-windows-msvc");
+    ArchSpec D("aarch64-unknown-linux-android");
+
+    ASSERT_TRUE(A.TripleVendorWasSpecified());
+    ASSERT_FALSE(A.TripleOSWasSpecified());
+    ASSERT_FALSE(A.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(B.TripleVendorWasSpecified());
+    ASSERT_TRUE(B.TripleOSWasSpecified());
+    ASSERT_FALSE(B.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(C.TripleVendorWasSpecified());
+    ASSERT_TRUE(C.TripleOSWasSpecified());
+    ASSERT_TRUE(C.TripleEnvironmentWasSpecified());
+
+    ASSERT_TRUE(D.TripleVendorWasSpecified());
+    ASSERT_TRUE(D.TripleOSWasSpecified());
+    ASSERT_TRUE(D.TripleEnvironmentWasSpecified());
+  }
+}