Revert r292214 "[Support/Compression] - Change zlib API to return Error instead of custom status."

It broked clang:
http://lab.llvm.org:8080/green//job/clang-stage1-cmake-RA-incremental_build/34218/consoleFull#46141505449ba4694-19c4-4d7e-bec5-911270d8a58c

llvm-svn: 292217

1 files changed, 36 insertions, 47 deletions

diff --git a/llvm/lib/Support/Compression.cpp b/llvm/lib/Support/Compression.cpp
index c279d10f6c6..5d556462e89 100644
--- a/llvm/lib/Support/Compression.cpp
+++ b/llvm/lib/Support/Compression.cpp
@@ -16,7 +16,6 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/Compiler.h"
-#include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #if LLVM_ENABLE_ZLIB == 1 && HAVE_ZLIB_H
 #include <zlib.h>
@@ -25,10 +24,6 @@
 using namespace llvm;
 
 #if LLVM_ENABLE_ZLIB == 1 && HAVE_LIBZ
-static Error createError(StringRef Err) {
-  return make_error<StringError>(Err, inconvertibleErrorCode());
-}
-
 static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) {
   switch (Level) {
     case zlib::NoCompression: return 0;
@@ -39,59 +34,53 @@ static int encodeZlibCompressionLevel(zlib::CompressionLevel Level) {
   llvm_unreachable("Invalid zlib::CompressionLevel!");
 }
 
-static StringRef convertZlibCodeToString(int Code) {
-  switch (Code) {
-  case Z_MEM_ERROR:
-    return "zlib error: Z_MEM_ERROR";
-  case Z_BUF_ERROR:
-    return "zlib error: Z_BUF_ERROR";
-  case Z_STREAM_ERROR:
-    return "zlib error: Z_STREAM_ERROR";
-  case Z_DATA_ERROR:
-    return "zlib error: Z_DATA_ERROR";
-  case Z_OK:
-  default:
-    llvm_unreachable("unknown or unexpected zlib status code");
+static zlib::Status encodeZlibReturnValue(int ReturnValue) {
+  switch (ReturnValue) {
+    case Z_OK: return zlib::StatusOK;
+    case Z_MEM_ERROR: return zlib::StatusOutOfMemory;
+    case Z_BUF_ERROR: return zlib::StatusBufferTooShort;
+    case Z_STREAM_ERROR: return zlib::StatusInvalidArg;
+    case Z_DATA_ERROR: return zlib::StatusInvalidData;
+    default: llvm_unreachable("unknown zlib return status!");
   }
 }
 
 bool zlib::isAvailable() { return true; }
-
-Error zlib::compress(StringRef InputBuffer,
-                     SmallVectorImpl<char> &CompressedBuffer,
-                     CompressionLevel Level) {
+zlib::Status zlib::compress(StringRef InputBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
+                            CompressionLevel Level) {
   unsigned long CompressedSize = ::compressBound(InputBuffer.size());
   CompressedBuffer.resize(CompressedSize);
   int CLevel = encodeZlibCompressionLevel(Level);
-  int Res = ::compress2((Bytef *)CompressedBuffer.data(), &CompressedSize,
-                        (const Bytef *)InputBuffer.data(), InputBuffer.size(),
-                        CLevel);
+  Status Res = encodeZlibReturnValue(::compress2(
+      (Bytef *)CompressedBuffer.data(), &CompressedSize,
+      (const Bytef *)InputBuffer.data(), InputBuffer.size(), CLevel));
   // Tell MemorySanitizer that zlib output buffer is fully initialized.
   // This avoids a false report when running LLVM with uninstrumented ZLib.
   __msan_unpoison(CompressedBuffer.data(), CompressedSize);
   CompressedBuffer.resize(CompressedSize);
-  return Res ? createError(convertZlibCodeToString(Res)) : Error::success();
+  return Res;
 }
 
-Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
-                       size_t &UncompressedSize) {
-  int Res =
+zlib::Status zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                              size_t &UncompressedSize) {
+  Status Res = encodeZlibReturnValue(
       ::uncompress((Bytef *)UncompressedBuffer, (uLongf *)&UncompressedSize,
-                   (const Bytef *)InputBuffer.data(), InputBuffer.size());
+                   (const Bytef *)InputBuffer.data(), InputBuffer.size()));
   // Tell MemorySanitizer that zlib output buffer is fully initialized.
   // This avoids a false report when running LLVM with uninstrumented ZLib.
   __msan_unpoison(UncompressedBuffer, UncompressedSize);
-  return Res ? createError(convertZlibCodeToString(Res)) : Error::success();
+  return Res;
 }
 
-Error zlib::uncompress(StringRef InputBuffer,
-                       SmallVectorImpl<char> &UncompressedBuffer,
-                       size_t UncompressedSize) {
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+                              SmallVectorImpl<char> &UncompressedBuffer,
+                              size_t UncompressedSize) {
   UncompressedBuffer.resize(UncompressedSize);
-  Error E =
+  Status Res =
       uncompress(InputBuffer, UncompressedBuffer.data(), UncompressedSize);
   UncompressedBuffer.resize(UncompressedSize);
-  return E;
+  return Res;
 }
 
 uint32_t zlib::crc32(StringRef Buffer) {
@@ -100,19 +89,19 @@ uint32_t zlib::crc32(StringRef Buffer) {
 
 #else
 bool zlib::isAvailable() { return false; }
-Error zlib::compress(StringRef InputBuffer,
-                     SmallVectorImpl<char> &CompressedBuffer,
-                     CompressionLevel Level) {
-  llvm_unreachable("zlib::compress is unavailable");
+zlib::Status zlib::compress(StringRef InputBuffer,
+                            SmallVectorImpl<char> &CompressedBuffer,
+                            CompressionLevel Level) {
+  return zlib::StatusUnsupported;
 }
-Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
-                       size_t &UncompressedSize) {
-  llvm_unreachable("zlib::uncompress is unavailable");
+zlib::Status zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                              size_t &UncompressedSize) {
+  return zlib::StatusUnsupported;
 }
-Error zlib::uncompress(StringRef InputBuffer,
-                       SmallVectorImpl<char> &UncompressedBuffer,
-                       size_t UncompressedSize) {
-  llvm_unreachable("zlib::uncompress is unavailable");
+zlib::Status zlib::uncompress(StringRef InputBuffer,
+                              SmallVectorImpl<char> &UncompressedBuffer,
+                              size_t UncompressedSize) {
+  return zlib::StatusUnsupported;
 }
 uint32_t zlib::crc32(StringRef Buffer) {
   llvm_unreachable("zlib::crc32 is unavailable");