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

6 files changed, 72 insertions, 83 deletions

diff --git a/llvm/include/llvm/Support/Compression.h b/llvm/include/llvm/Support/Compression.h
index 2d191abe4b1..5bf7031fe9f 100644
--- a/llvm/include/llvm/Support/Compression.h
+++ b/llvm/include/llvm/Support/Compression.h
@@ -18,7 +18,6 @@
 
 namespace llvm {
 template <typename T> class SmallVectorImpl;
-class Error;
 class StringRef;
 
 namespace zlib {
@@ -30,17 +29,26 @@ enum CompressionLevel {
   BestSizeCompression
 };
 
+enum Status {
+  StatusOK,
+  StatusUnsupported,    // zlib is unavailable
+  StatusOutOfMemory,    // there was not enough memory
+  StatusBufferTooShort, // there was not enough room in the output buffer
+  StatusInvalidArg,     // invalid input parameter
+  StatusInvalidData     // data was corrupted or incomplete
+};
+
 bool isAvailable();
 
-Error compress(StringRef InputBuffer, SmallVectorImpl<char> &CompressedBuffer,
-               CompressionLevel Level = DefaultCompression);
+Status compress(StringRef InputBuffer, SmallVectorImpl<char> &CompressedBuffer,
+                CompressionLevel Level = DefaultCompression);
 
-Error uncompress(StringRef InputBuffer, char *UncompressedBuffer,
-                 size_t &UncompressedSize);
+Status uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                  size_t &UncompressedSize);
 
-Error uncompress(StringRef InputBuffer,
-                 SmallVectorImpl<char> &UncompressedBuffer,
-                 size_t UncompressedSize);
+Status uncompress(StringRef InputBuffer,
+                  SmallVectorImpl<char> &UncompressedBuffer,
+                  size_t UncompressedSize);
 
 uint32_t crc32(StringRef Buffer);
 
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 0e02cdb4ca0..a8c88dda693 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -32,7 +32,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/Endian.h"
-#include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/StringSaver.h"
 #include <vector>
@@ -1038,10 +1037,10 @@ void ELFObjectWriter::writeSectionData(const MCAssembler &Asm, MCSection &Sec,
   setStream(OldStream);
 
   SmallVector<char, 128> CompressedContents;
-  if (Error E = zlib::compress(
-          StringRef(UncompressedData.data(), UncompressedData.size()),
-          CompressedContents)) {
-    consumeError(std::move(E));
+  zlib::Status Success = zlib::compress(
+      StringRef(UncompressedData.data(), UncompressedData.size()),
+      CompressedContents);
+  if (Success != zlib::StatusOK) {
     getStream() << UncompressedData;
     return;
   }
diff --git a/llvm/lib/Object/Decompressor.cpp b/llvm/lib/Object/Decompressor.cpp
index 0be602b1fc1..bca41fd9f48 100644
--- a/llvm/lib/Object/Decompressor.cpp
+++ b/llvm/lib/Object/Decompressor.cpp
@@ -95,5 +95,8 @@ Error Decompressor::decompress(SmallString<32> &Out) {
 
 Error Decompressor::decompress(MutableArrayRef<char> Buffer) {
   size_t Size = Buffer.size();
-  return zlib::uncompress(SectionData, Buffer.data(), Size);
+  zlib::Status Status = zlib::uncompress(SectionData, Buffer.data(), Size);
+  if (Status != zlib::StatusOK)
+    return createError("decompression failed");
+  return Error::success();
 }
diff --git a/llvm/lib/ProfileData/InstrProf.cpp b/llvm/lib/ProfileData/InstrProf.cpp
index eb676602632..74acd9e5e20 100644
--- a/llvm/lib/ProfileData/InstrProf.cpp
+++ b/llvm/lib/ProfileData/InstrProf.cpp
@@ -271,12 +271,12 @@ Error collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
   }
 
   SmallString<128> CompressedNameStrings;
-  Error E = zlib::compress(StringRef(UncompressedNameStrings),
-                           CompressedNameStrings, zlib::BestSizeCompression);
-  if (E) {
-    consumeError(std::move(E));
+  zlib::Status Success =
+      zlib::compress(StringRef(UncompressedNameStrings), CompressedNameStrings,
+                     zlib::BestSizeCompression);
+
+  if (Success != zlib::StatusOK)
     return make_error<InstrProfError>(instrprof_error::compress_failed);
-  }
 
   return WriteStringToResult(CompressedNameStrings.size(),
                              CompressedNameStrings);
@@ -315,12 +315,9 @@ Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
     if (isCompressed) {
       StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
                                       CompressedSize);
-      if (Error E =
-              zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
-                               UncompressedSize)) {
-        consumeError(std::move(E));
+      if (zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
+                           UncompressedSize) != zlib::StatusOK)
         return make_error<InstrProfError>(instrprof_error::uncompress_failed);
-      }
       P += CompressedSize;
       NameStrings = StringRef(UncompressedNameStrings.data(),
                               UncompressedNameStrings.size());
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");
diff --git a/llvm/unittests/Support/CompressionTest.cpp b/llvm/unittests/Support/CompressionTest.cpp
index 18a6175460d..36b84d85f22 100644
--- a/llvm/unittests/Support/CompressionTest.cpp
+++ b/llvm/unittests/Support/CompressionTest.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/Compression.h"
-#include "llvm/Support/Error.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Config/config.h"
@@ -27,21 +26,15 @@ namespace {
 void TestZlibCompression(StringRef Input, zlib::CompressionLevel Level) {
   SmallString<32> Compressed;
   SmallString<32> Uncompressed;
-
-  Error E = zlib::compress(Input, Compressed, Level);
-  EXPECT_FALSE(E);
-  consumeError(std::move(E));
-
+  EXPECT_EQ(zlib::StatusOK, zlib::compress(Input, Compressed, Level));
   // Check that uncompressed buffer is the same as original.
-  E = zlib::uncompress(Compressed, Uncompressed, Input.size());
-  EXPECT_FALSE(E);
-  consumeError(std::move(E));
-
+  EXPECT_EQ(zlib::StatusOK,
+            zlib::uncompress(Compressed, Uncompressed, Input.size()));
   EXPECT_EQ(Input, Uncompressed);
   if (Input.size() > 0) {
     // Uncompression fails if expected length is too short.
-    E = zlib::uncompress(Compressed, Uncompressed, Input.size() - 1);
-    EXPECT_EQ("zlib error: Z_BUF_ERROR", llvm::toString(std::move(E)));
+    EXPECT_EQ(zlib::StatusBufferTooShort,
+              zlib::uncompress(Compressed, Uncompressed, Input.size() - 1));
   }
 }