Index: lld/ELF/Strings.h
===================================================================
--- lld/ELF/Strings.h
+++ lld/ELF/Strings.h
@@ -15,6 +15,7 @@
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/GlobPattern.h"
 #include <vector>
 
 namespace lld {
@@ -56,30 +57,6 @@
   mutable size_t Size;
 };
 
-// This class represents a glob pattern. Supported metacharacters
-// are "*", "?", "[<chars>]" and "[^<chars>]".
-class GlobPattern {
-public:
-  explicit GlobPattern(StringRef Pat);
-  bool match(StringRef S) const;
-
-private:
-  bool matchOne(ArrayRef<llvm::BitVector> Pat, StringRef S) const;
-  llvm::BitVector scan(StringRef &S);
-  llvm::BitVector expand(StringRef S);
-
-  // Parsed glob pattern.
-  std::vector<llvm::BitVector> Tokens;
-
-  // A glob pattern given to this class. This is for error reporting.
-  StringRef Original;
-
-  // The following members are for optimization.
-  llvm::Optional<StringRef> Exact;
-  llvm::Optional<StringRef> Prefix;
-  llvm::Optional<StringRef> Suffix;
-};
-
 // This class represents multiple glob patterns.
 class StringMatcher {
 public:
@@ -89,7 +66,7 @@
   bool match(StringRef S) const;
 
 private:
-  std::vector<GlobPattern> Patterns;
+  std::vector<llvm::GlobPattern> Patterns;
 };
 
 // Returns a demangled C++ symbol name. If Name is not a mangled
Index: lld/ELF/Strings.cpp
===================================================================
--- lld/ELF/Strings.cpp
+++ lld/ELF/Strings.cpp
@@ -21,134 +21,14 @@
 using namespace lld;
 using namespace lld::elf;
 
-// This is a scanner for the glob pattern.
-// A glob pattern token is one of "*", "?", "[<chars>]", "[^<chars>]"
-// (which is a negative form of "[<chars>]"), or a non-meta character.
-// This function returns the first token in S.
-BitVector GlobPattern::scan(StringRef &S) {
-  switch (S[0]) {
-  case '*':
-    S = S.substr(1);
-    // '*' is represented by an empty bitvector.
-    // All other bitvectors are 256-bit long.
-    return BitVector();
-  case '?':
-    S = S.substr(1);
-    return BitVector(256, true);
-  case '[': {
-    size_t End = S.find(']', 1);
-    if (End == StringRef::npos) {
-      error("invalid glob pattern: " + Original);
-      S = "";
-      return BitVector(256, false);
-    }
-    StringRef Chars = S.substr(1, End - 1);
-    S = S.substr(End + 1);
-    if (Chars.startswith("^"))
-      return expand(Chars.substr(1)).flip();
-    return expand(Chars);
-  }
-  default:
-    BitVector BV(256, false);
-    BV[S[0]] = true;
-    S = S.substr(1);
-    return BV;
-  }
-}
-
-// Expands character ranges and returns a bitmap.
-// For example, "a-cf-hz" is expanded to "abcfghz".
-BitVector GlobPattern::expand(StringRef S) {
-  BitVector BV(256, false);
-
-  // Expand "x-y".
-  for (;;) {
-    if (S.size() < 3)
-      break;
-
-    // If it doesn't start with something like "x-y",
-    // consume the first character and proceed.
-    if (S[1] != '-') {
-      BV[S[0]] = true;
-      S = S.substr(1);
-      continue;
-    }
-
-    // It must be in the form of "x-y".
-    // Validate it and then interpret the range.
-    if (S[0] > S[2]) {
-      error("invalid glob pattern: " + Original);
-      return BV;
-    }
-    for (int C = S[0]; C <= S[2]; ++C)
-      BV[C] = true;
-    S = S.substr(3);
-  }
-
-  for (char C : S)
-    BV[C] = true;
-  return BV;
-}
-
-GlobPattern::GlobPattern(StringRef S) : Original(S) {
-  if (!hasWildcard(S)) {
-    // S doesn't contain any metacharacter,
-    // so the regular string comparison should work.
-    Exact = S;
-  } else if (S.endswith("*") && !hasWildcard(S.drop_back())) {
-    // S is something like "foo*". We can use startswith().
-    Prefix = S.drop_back();
-  } else if (S.startswith("*") && !hasWildcard(S.drop_front())) {
-    // S is something like "*foo". We can use endswith().
-    Suffix = S.drop_front();
-  } else {
-    // Otherwise, we need to do real glob pattern matching.
-    // Parse the pattern now.
-    while (!S.empty())
-      Tokens.push_back(scan(S));
-  }
-}
-
-bool GlobPattern::match(StringRef S) const {
-  if (Exact)
-    return S == *Exact;
-  if (Prefix)
-    return S.startswith(*Prefix);
-  if (Suffix)
-    return S.endswith(*Suffix);
-  return matchOne(Tokens, S);
-}
-
-// Runs glob pattern Pats against string S.
-bool GlobPattern::matchOne(ArrayRef<BitVector> Pats, StringRef S) const {
-  for (;;) {
-    if (Pats.empty())
-      return S.empty();
-
-    // If Pats[0] is '*', try to match Pats[1..] against all possible
-    // substrings of S to see at least one pattern succeeds.
-    if (Pats[0].size() == 0) {
-      Pats = Pats.slice(1);
-      if (Pats.empty())
-        // Fast path. If a pattern is '*', it matches anything.
-        return true;
-      for (size_t I = 0, E = S.size(); I < E; ++I)
-        if (matchOne(Pats, S.substr(I)))
-          return true;
-      return false;
-    }
-
-    // If Pats[0] is not '*', it must consume one character.
-    if (S.empty() || !Pats[0][S[0]])
-      return false;
-    Pats = Pats.slice(1);
-    S = S.substr(1);
-  }
-}
-
 StringMatcher::StringMatcher(const std::vector<StringRef> &Pat) {
-  for (StringRef S : Pat)
-    Patterns.push_back(GlobPattern(S));
+  for (StringRef S : Pat) {
+    Expected<GlobPattern> Pat = GlobPattern::create(S);
+    if (!Pat)
+      error(toString(Pat.takeError()));
+    else
+      Patterns.push_back(*Pat);
+  }
 }
 
 bool StringMatcher::match(StringRef S) const {
Index: llvm/include/llvm/Support/GlobPattern.h
===================================================================
--- /dev/null
+++ llvm/include/llvm/Support/GlobPattern.h
@@ -0,0 +1,48 @@
+//===-- GlobPattern.h - glob pattern matcher implementation -*- C++ -*-----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a glob pattern matcher. The glob pattern is the
+// rule used by the shell.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_GLOB_PATTERN_H
+#define LLVM_SUPPORT_GLOB_PATTERN_H
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
+#include <vector>
+
+// This class represents a glob pattern. Supported metacharacters
+// are "*", "?", "[<chars>]" and "[^<chars>]".
+namespace llvm {
+class BitVector;
+template <typename T> class ArrayRef;
+
+class GlobPattern {
+public:
+  static Expected<GlobPattern> create(StringRef Pat);
+  bool match(StringRef S) const;
+
+private:
+  bool matchOne(ArrayRef<BitVector> Pat, StringRef S) const;
+
+  // Parsed glob pattern.
+  std::vector<BitVector> Tokens;
+
+  // The following members are for optimization.
+  Optional<StringRef> Exact;
+  Optional<StringRef> Prefix;
+  Optional<StringRef> Suffix;
+};
+}
+
+#endif // LLVM_SUPPORT_GLOB_PATTERN_H
Index: llvm/lib/Support/CMakeLists.txt
===================================================================
--- llvm/lib/Support/CMakeLists.txt
+++ llvm/lib/Support/CMakeLists.txt
@@ -56,6 +56,7 @@
   FoldingSet.cpp
   FormattedStream.cpp
   FormatVariadic.cpp
+  GlobPattern.cpp
   GraphWriter.cpp
   Hashing.cpp
   IntEqClasses.cpp
Index: llvm/lib/Support/GlobPattern.cpp
===================================================================
--- /dev/null
+++ llvm/lib/Support/GlobPattern.cpp
@@ -0,0 +1,167 @@
+//===-- GlobPattern.cpp - Glob pattern matcher implementation -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a glob pattern matcher.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/GlobPattern.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Errc.h"
+
+using namespace llvm;
+
+static bool hasWildcard(StringRef S) {
+  return S.find_first_of("?*[") != StringRef::npos;
+}
+
+// Expands character ranges and returns a bitmap.
+// For example, "a-cf-hz" is expanded to "abcfghz".
+static Expected<BitVector> expand(StringRef S, StringRef Original) {
+  BitVector BV(256, false);
+
+  // Expand "x-y".
+  for (;;) {
+    if (S.size() < 3)
+      break;
+
+    // If it doesn't start with something like "x-y",
+    // consume the first character and proceed.
+    if (S[1] != '-') {
+      BV[S[0]] = true;
+      S = S.substr(1);
+      continue;
+    }
+
+    // It must be in the form of "x-y".
+    // Validate it and then interpret the range.
+    if (S[0] > S[2])
+      return make_error<StringError>("invalid glob pattern: " + Original,
+                                     errc::invalid_argument);
+
+    for (int C = S[0]; C <= S[2]; ++C)
+      BV[C] = true;
+    S = S.substr(3);
+  }
+
+  for (char C : S)
+    BV[C] = true;
+  return BV;
+}
+
+// This is a scanner for the glob pattern.
+// A glob pattern token is one of "*", "?", "[<chars>]", "[^<chars>]"
+// (which is a negative form of "[<chars>]"), or a non-meta character.
+// This function returns the first token in S.
+static Expected<BitVector> scan(StringRef &S, StringRef Original) {
+  switch (S[0]) {
+  case '*':
+    S = S.substr(1);
+    // '*' is represented by an empty bitvector.
+    // All other bitvectors are 256-bit long.
+    return BitVector();
+  case '?':
+    S = S.substr(1);
+    return BitVector(256, true);
+  case '[': {
+    size_t End = S.find(']', 1);
+    if (End == StringRef::npos)
+      return make_error<StringError>("invalid glob pattern: " + Original,
+                                     errc::invalid_argument);
+
+    StringRef Chars = S.substr(1, End - 1);
+    S = S.substr(End + 1);
+    if (Chars.startswith("^")) {
+      Expected<BitVector> BV = expand(Chars.substr(1), Original);
+      if (!BV)
+        return BV.takeError();
+      return BV->flip();
+    }
+    return expand(Chars, Original);
+  }
+  default:
+    BitVector BV(256, false);
+    BV[S[0]] = true;
+    S = S.substr(1);
+    return BV;
+  }
+}
+
+Expected<GlobPattern> GlobPattern::create(StringRef S) {
+  GlobPattern Pat;
+
+  // S doesn't contain any metacharacter,
+  // so the regular string comparison should work.
+  if (!hasWildcard(S)) {
+    Pat.Exact = S;
+    return Pat;
+  }
+
+  // S is something like "foo*". We can use startswith().
+  if (S.endswith("*") && !hasWildcard(S.drop_back())) {
+    Pat.Prefix = S.drop_back();
+    return Pat;
+  }
+
+  // S is something like "*foo". We can use endswith().
+  if (S.startswith("*") && !hasWildcard(S.drop_front())) {
+    Pat.Suffix = S.drop_front();
+    return Pat;
+  }
+
+  // Otherwise, we need to do real glob pattern matching.
+  // Parse the pattern now.
+  StringRef Original = S;
+  while (!S.empty()) {
+    Expected<BitVector> BV = scan(S, Original);
+    if (!BV)
+      return BV.takeError();
+    Pat.Tokens.push_back(*BV);
+  }
+  return Pat;
+}
+
+bool GlobPattern::match(StringRef S) const {
+  if (Exact)
+    return S == *Exact;
+  if (Prefix)
+    return S.startswith(*Prefix);
+  if (Suffix)
+    return S.endswith(*Suffix);
+  return matchOne(Tokens, S);
+}
+
+// Runs glob pattern Pats against string S.
+bool GlobPattern::matchOne(ArrayRef<BitVector> Pats, StringRef S) const {
+  for (;;) {
+    if (Pats.empty())
+      return S.empty();
+
+    // If Pats[0] is '*', try to match Pats[1..] against all possible
+    // substrings of S to see at least one pattern succeeds.
+    if (Pats[0].size() == 0) {
+      Pats = Pats.slice(1);
+      if (Pats.empty())
+        // Fast path. If a pattern is '*', it matches anything.
+        return true;
+      for (size_t I = 0, E = S.size(); I < E; ++I)
+        if (matchOne(Pats, S.substr(I)))
+          return true;
+      return false;
+    }
+
+    // If Pats[0] is not '*', it must consume one character.
+    if (S.empty() || !Pats[0][S[0]])
+      return false;
+    Pats = Pats.slice(1);
+    S = S.substr(1);
+  }
+}
Index: llvm/unittests/Support/CMakeLists.txt
===================================================================
--- llvm/unittests/Support/CMakeLists.txt
+++ llvm/unittests/Support/CMakeLists.txt
@@ -17,10 +17,11 @@
   DwarfTest.cpp
   EndianStreamTest.cpp
   EndianTest.cpp
-  ErrorTest.cpp
   ErrorOrTest.cpp
+  ErrorTest.cpp
   FileOutputBufferTest.cpp
   FormatVariadicTest.cpp
+  GlobPatternTest.cpp
   Host.cpp
   LEB128Test.cpp
   LineIteratorTest.cpp
Index: llvm/unittests/Support/GlobPatternTest.cpp
===================================================================
--- /dev/null
+++ llvm/unittests/Support/GlobPatternTest.cpp
@@ -0,0 +1,70 @@
+//===- llvm/unittest/Support/GlobPatternTest.cpp --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/GlobPattern.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+namespace {
+
+class GlobPatternTest : public ::testing::Test {};
+
+TEST_F(GlobPatternTest, Basics) {
+  Expected<GlobPattern> Pat1 = GlobPattern::create("");
+  EXPECT_TRUE((bool)Pat1);
+  EXPECT_TRUE(Pat1->match(""));
+  EXPECT_FALSE(Pat1->match("a"));
+
+  Expected<GlobPattern> Pat2 = GlobPattern::create("ab*c*def");
+  EXPECT_TRUE((bool)Pat2);
+  EXPECT_TRUE(Pat2->match("abcdef"));
+  EXPECT_TRUE(Pat2->match("abxcxdef"));
+  EXPECT_FALSE(Pat2->match(""));
+  EXPECT_FALSE(Pat2->match("xabcdef"));
+  EXPECT_FALSE(Pat2->match("abcdefx"));
+
+  Expected<GlobPattern> Pat3 = GlobPattern::create("a??c");
+  EXPECT_TRUE((bool)Pat3);
+  EXPECT_TRUE(Pat3->match("axxc"));
+  EXPECT_FALSE(Pat3->match("axxx"));
+  EXPECT_FALSE(Pat3->match(""));
+
+  Expected<GlobPattern> Pat4 = GlobPattern::create("[abc-fy-z]");
+  EXPECT_TRUE((bool)Pat4);
+  EXPECT_TRUE(Pat4->match("a"));
+  EXPECT_TRUE(Pat4->match("b"));
+  EXPECT_TRUE(Pat4->match("c"));
+  EXPECT_TRUE(Pat4->match("d"));
+  EXPECT_TRUE(Pat4->match("e"));
+  EXPECT_TRUE(Pat4->match("f"));
+  EXPECT_TRUE(Pat4->match("y"));
+  EXPECT_TRUE(Pat4->match("z"));
+  EXPECT_FALSE(Pat4->match("g"));
+  EXPECT_FALSE(Pat4->match(""));
+
+  Expected<GlobPattern> Pat5 = GlobPattern::create("[^abc-fy-z]");
+  EXPECT_TRUE((bool)Pat5);
+  EXPECT_TRUE(Pat5->match("g"));
+  EXPECT_FALSE(Pat5->match("a"));
+  EXPECT_FALSE(Pat5->match("b"));
+  EXPECT_FALSE(Pat5->match("c"));
+  EXPECT_FALSE(Pat5->match("d"));
+  EXPECT_FALSE(Pat5->match("e"));
+  EXPECT_FALSE(Pat5->match("f"));
+  EXPECT_FALSE(Pat5->match("y"));
+  EXPECT_FALSE(Pat5->match("z"));
+  EXPECT_FALSE(Pat5->match(""));
+}
+
+TEST_F(GlobPatternTest, Invalid) {
+  Expected<GlobPattern> Pat1 = GlobPattern::create("[");
+  EXPECT_FALSE((bool)Pat1);
+  handleAllErrors(Pat1.takeError(), [&](ErrorInfoBase &EIB) {});
+}
+}