Reapply "[Mangler] Add unit tests to the compression routines.""

This reverts commit f4ccef2.

Author: nadavrot

unittests/Basic/CMakeLists.txt

@@ -20,6 +20,7 @@ add_swift_unittest(SwiftBasicTests
   Unicode.cpp
   BlotMapVectorTest.cpp
   PointerIntEnumTest.cpp
+  CompressionTests.cpp
   ${generated_tests}
   )
 

unittests/Basic/CompressionTests.cpp

@@ -0,0 +1,89 @@
+//===- CompressionTests.cpp - for swift/ABI/Compression.h -----------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+#include "swift/ABI/Compression.h"
+#include "gtest/gtest.h"
+
+using namespace swift::Compress;
+
+const char* TestValues[] = {"AA", "r", "J", "Swift","A", "ArrayStringPrintable",
+  "AB","JA","YA","encodeCBCString", "HelloWorld", "long", "_TThisIsATestString"
+  "Done", "Smile","_S_S_S", "________", "_TSLZ","Lempel_Ziv", "Ziv_and_Lempel",
+  "JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ",
+  "ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ",
+  "YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY",
+  "AllDone", "UnderWaterCordlessDrill","UnderWaterAngleGrinder", "Printable", "Clone", "Collection"
+  "__TwxxV14StdlibUnittest24MinimalForwardCollection",
+  "__TMPVs15ContiguousArray",
+  "__TIF14StdlibUnittest13checkSequenceu0_Rxs14CollectionType_s12SequenceTypeWx9Generator7Element_zW_9GeneratorS3__rFTxq",
+  "__TTSg5VSS13CharacterViewS_s14CollectionTypes_GVs17IndexingGeneratorS__GS1_S__s13GeneratorTypes_VS_5IndexS3_s16Forwar",
+  ""};
+
+// Test that the code book compression round trips.
+TEST(Compression, RoundTripCBC) {
+    for (const char* N : TestValues) {
+      std::string encoded = EncodeCBCString(N);
+      std::string decoded = DecodeCBCString(encoded);
+      EXPECT_EQ(decoded, std::string(N));
+    }
+}
+
+// Test flat (non variable length) encoding.
+TEST(Compression, FlatEncoding) {
+    for (const char* input : TestValues) {
+      llvm::APInt flat_code = EncodeStringAsNumber(input, EncodingKind::Fixed);
+      std::string flat_input = DecodeStringFromNumber(flat_code, EncodingKind::Fixed);
+      EXPECT_EQ(flat_input, input);
+    }
+
+    // Check that we can encode and decode all numbers and that we get the
+    // correct value after round trips.
+    for (int i = 0; i < 10000; i++) {
+      llvm::APInt num = llvm::APInt(64, i);
+      std::string encoded = DecodeStringFromNumber(num, EncodingKind::Fixed);
+      llvm::APInt decoded_num = EncodeStringAsNumber(encoded, EncodingKind::Fixed);
+      EXPECT_EQ(num.getZExtValue(), decoded_num.getZExtValue());
+    }
+}
+
+// Test variable length encoding.
+TEST(Compression, VarEncoding) {
+    for (const char* input : TestValues) {
+      llvm::APInt var_code = EncodeStringAsNumber(input, EncodingKind::Variable);
+      std::string var_input = DecodeStringFromNumber(var_code, EncodingKind::Variable);
+      EXPECT_EQ(var_input, input);
+    }
+}
+
+TEST(Compression, VariableLength) {
+    for (const char* input : TestValues) {
+      llvm::APInt code = EncodeStringAsNumber(input, EncodingKind::Variable);
+
+      std::string encoded = DecodeStringFromNumber(code, EncodingKind::Fixed);
+      llvm::APInt code2 =   EncodeStringAsNumber(encoded, EncodingKind::Fixed);
+
+      std::string encoded2 = DecodeStringFromNumber(code2, EncodingKind::Fixed);
+      llvm::APInt code3 =    EncodeStringAsNumber(encoded2, EncodingKind::Fixed);
+      EXPECT_EQ(code.toString(10, false), code2.toString(10, false));
+      EXPECT_EQ(code3, code2);
+
+      std::string decoded = DecodeStringFromNumber(code2, EncodingKind::Variable);
+      EXPECT_EQ(decoded, input);
+    }
+}
+
+TEST(Compression, FullCompression) {
+    for (const char* input : TestValues) {
+      std::string compressed = CompressName(input);
+      std::string decompressed = DecompressName(compressed);
+      EXPECT_EQ(std::string(input), decompressed);
+    }
+}