[llvm-commits] [llvm] r152003 - in /llvm/trunk: include/llvm/ADT/StringRef.h lib/Support/StringRef.cpp unittests/ADT/StringRefTest.cpp

[Chandler Carruth]

Author: chandlerc
Date: Sun Mar  4 04:55:27 2012
New Revision: 152003

URL: http://llvm.org/viewvc/llvm-project?rev=152003&view=rev
Log:
Add generic support for hashing StringRef objects using the new hashing library.

Modified:
    llvm/trunk/include/llvm/ADT/StringRef.h
    llvm/trunk/lib/Support/StringRef.cpp
    llvm/trunk/unittests/ADT/StringRefTest.cpp

Modified: llvm/trunk/include/llvm/ADT/StringRef.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/StringRef.h?rev=152003&r1=152002&r2=152003&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/StringRef.h (original)
+++ llvm/trunk/include/llvm/ADT/StringRef.h Sun Mar  4 04:55:27 2012
@@ -19,6 +19,7 @@
   template<typename T>
   class SmallVectorImpl;
   class APInt;
+  class hash_code;
 
   /// StringRef - Represent a constant reference to a string, i.e. a character
   /// array and a length, which need not be null terminated.
@@ -490,6 +491,9 @@
 
   /// @}
 
+  /// \brief Compute a hash_code for a StringRef.
+  hash_code hash_value(StringRef S);
+
   // StringRefs can be treated like a POD type.
   template <typename T> struct isPodLike;
   template <> struct isPodLike<StringRef> { static const bool value = true; };

Modified: llvm/trunk/lib/Support/StringRef.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/StringRef.cpp?rev=152003&r1=152002&r2=152003&view=diff
==============================================================================
--- llvm/trunk/lib/Support/StringRef.cpp (original)
+++ llvm/trunk/lib/Support/StringRef.cpp Sun Mar  4 04:55:27 2012
@@ -10,6 +10,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/edit_distance.h"
 #include <bitset>
 
@@ -447,3 +448,9 @@
 
   return false;
 }
+
+
+// Implementation of StringRef hashing.
+hash_code llvm::hash_value(StringRef S) {
+  return hash_combine_range(S.begin(), S.end());
+}

Modified: llvm/trunk/unittests/ADT/StringRefTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/StringRefTest.cpp?rev=152003&r1=152002&r2=152003&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/StringRefTest.cpp (original)
+++ llvm/trunk/unittests/ADT/StringRefTest.cpp Sun Mar  4 04:55:27 2012
@@ -9,6 +9,7 @@
 
 #include "gtest/gtest.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
@@ -291,4 +292,22 @@
   EXPECT_EQ("hello", OS.str());
 }
 
+TEST(StringRefTest, Hashing) {
+  EXPECT_EQ(hash_value(std::string()), hash_value(StringRef()));
+  EXPECT_EQ(hash_value(std::string()), hash_value(StringRef("")));
+  std::string S = "hello world";
+  hash_code H = hash_value(S);
+  EXPECT_EQ(H, hash_value(StringRef("hello world")));
+  EXPECT_EQ(H, hash_value(StringRef(S)));
+  EXPECT_NE(H, hash_value(StringRef("hello worl")));
+  EXPECT_EQ(hash_value(std::string("hello worl")),
+            hash_value(StringRef("hello worl")));
+  EXPECT_NE(H, hash_value(StringRef("hello world ")));
+  EXPECT_EQ(hash_value(std::string("hello world ")),
+            hash_value(StringRef("hello world ")));
+  EXPECT_EQ(H, hash_value(StringRef("hello world\0")));
+  EXPECT_NE(hash_value(std::string("ello worl")),
+            hash_value(StringRef("hello world").slice(1, -1)));
+}
+
 } // end anonymous namespace