StringRef::copy shouldn't allocate anything for length 0 strings.
The BumpPtrAllocator currently doesn't handle zero length allocations well.
The discussion for how to fix that is ongoing. However, there's no need
for StringRef::copy to actually allocate anything here anyway, so just
return StringRef() when we get a zero length copy.
Reviewed by David Blaikie
llvm-svn: 264201
diff --git a/llvm/unittests/ADT/StringRefTest.cpp b/llvm/unittests/ADT/StringRefTest.cpp
index 6354026..66e5944 100644
--- a/llvm/unittests/ADT/StringRefTest.cpp
+++ b/llvm/unittests/ADT/StringRefTest.cpp
@@ -589,6 +589,15 @@
TEST(StringRefTest, AllocatorCopy) {
BumpPtrAllocator Alloc;
+ // First test empty strings. We don't want these to allocate anything on the
+ // allocator.
+ StringRef StrEmpty = "";
+ StringRef StrEmptyc = StrEmpty.copy(Alloc);
+ EXPECT_TRUE(StrEmpty.equals(StrEmptyc));
+ EXPECT_EQ(StrEmptyc.data(), nullptr);
+ EXPECT_EQ(StrEmptyc.size(), 0u);
+ EXPECT_EQ(Alloc.getTotalMemory(), 0u);
+
StringRef Str1 = "hello";
StringRef Str2 = "bye";
StringRef Str1c = Str1.copy(Alloc);