BitcodeWriter: Simplify and test writing blobs, NFC

Split helper out of EmitRecordWithAbbrevImpl called emitBlob to reduce
code duplication, and add a few tests for it.

No functionality change intended.

llvm-svn: 264550

llvm/unittests/Bitcode/BitstreamWriterTest.cpp

@@ -0,0 +1,59 @@
+//===- BitstreamWriterTest.cpp - Tests for BitstreamWriter ----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Bitcode/BitstreamWriter.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+TEST(BitstreamWriterTest, emitBlob) {
+  SmallString<64> Buffer;
+  BitstreamWriter W(Buffer);
+  W.emitBlob("str", /* ShouldEmitSize */ false);
+  EXPECT_EQ(StringRef("str\0", 4), Buffer);
+}
+
+TEST(BitstreamWriterTest, emitBlobWithSize) {
+  SmallString<64> Buffer;
+  {
+    BitstreamWriter W(Buffer);
+    W.emitBlob("str");
+  }
+  SmallString<64> Expected;
+  {
+    BitstreamWriter W(Expected);
+    W.EmitVBR(3, 6);
+    W.FlushToWord();
+    W.Emit('s', 8);
+    W.Emit('t', 8);
+    W.Emit('r', 8);
+    W.Emit(0, 8);
+  }
+  EXPECT_EQ(StringRef(Expected), Buffer);
+}
+
+TEST(BitstreamWriterTest, emitBlobEmpty) {
+  SmallString<64> Buffer;
+  BitstreamWriter W(Buffer);
+  W.emitBlob("", /* ShouldEmitSize */ false);
+  EXPECT_EQ(StringRef(""), Buffer);
+}
+
+TEST(BitstreamWriterTest, emitBlob4ByteAligned) {
+  SmallString<64> Buffer;
+  BitstreamWriter W(Buffer);
+  W.emitBlob("str0", /* ShouldEmitSize */ false);
+  EXPECT_EQ(StringRef("str0"), Buffer);
+}
+
+} // end namespace