Add generic support for hashing StringRef objects using the new hashing library.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152003 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/ADT/StringRef.h b/include/llvm/ADT/StringRef.h
index 53ebe6a..a2bb7fe 100644
--- a/include/llvm/ADT/StringRef.h
+++ b/include/llvm/ADT/StringRef.h
@@ -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; };
diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp
index 44e7325..1c28bf8 100644
--- a/lib/Support/StringRef.cpp
+++ b/lib/Support/StringRef.cpp
@@ -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());
+}
diff --git a/unittests/ADT/StringRefTest.cpp b/unittests/ADT/StringRefTest.cpp
index d910843..b2f6fdc 100644
--- a/unittests/ADT/StringRefTest.cpp
+++ b/unittests/ADT/StringRefTest.cpp
@@ -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