Remove raw_sha1_ostream

[teemperor]

Summary

raw_sha1_ostream was added as in 2016 as part of D16325 and the SHA1 implementation from that patch
has since then been used by a few other parts of LLVM. However, the raw_sha1_ostream class that
was also introduced by D16325 has no active users anywhere in LLVM.

The code itself looks perfectly fine, but as it's unused it doesn't seem worthwhile to make everyone
compile, maintain and run the tests for this class.

[davide]

I think this is fine. @mehdi_amini ?

[mehdi_amini]

If no one found a use for this long, that's reasonable.

(in general though, removing such utility isn't always obvious to me: in many cases I would use a utility if it exists but may not actually create a generic one just for my use)

llvm/include/llvm/Support/raw_sha1_ostream.h

-//==- raw_sha1_ostream.h - raw_ostream that compute SHA1        --*- C++ -*-==//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines the raw_sha1_ostream class.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_SUPPORT_RAW_SHA1_OSTREAM_H
-#define LLVM_SUPPORT_RAW_SHA1_OSTREAM_H
-
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/Support/SHA1.h"
-#include "llvm/Support/raw_ostream.h"
-
-namespace llvm {
-
-/// A raw_ostream that hash the content using the sha1 algorithm.
-class raw_sha1_ostream : public raw_ostream {
-  SHA1 State;
-
-  /// See raw_ostream::write_impl.
-  void write_impl(const char *Ptr, size_t Size) override {
-    State.update(ArrayRef<uint8_t>((const uint8_t *)Ptr, Size));
-  }
-
-public:
-  /// Return the current SHA1 hash for the content of the stream
-  StringRef sha1() {
-    flush();
-    return State.result();
-  }
-
-  /// Reset the internal state to start over from scratch.
-  void resetHash() { State.init(); }
-
-  uint64_t current_pos() const override { return 0; }
-};
-
-} // end llvm namespace
-
-#endif

llvm/unittests/Support/CMakeLists.txt

add_llvm_unittest(SupportTests
   VersionTupleTest.cpp
   VirtualFileSystemTest.cpp
   WithColorTest.cpp
   YAMLIOTest.cpp
   YAMLParserTest.cpp
   formatted_raw_ostream_test.cpp
   raw_ostream_test.cpp
   raw_pwrite_stream_test.cpp
-  raw_sha1_ostream_test.cpp
   xxhashTest.cpp
   )
 
 target_link_libraries(SupportTests PRIVATE LLVMTestingSupport)
 
 # Disable all warning for AlignOfTest.cpp,
 # as it does things intentionally, and there is no reliable way of
 # disabling all warnings for all the compilers by using pragmas.

llvm/unittests/Support/raw_sha1_ostream_test.cpp

-//===- llvm/unittest/Support/raw_ostream_test.cpp - raw_ostream tests -----===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Support/Format.h"
-#include "llvm/Support/raw_sha1_ostream.h"
-#include "gtest/gtest.h"
-
-#include <string>
-
-using namespace llvm;
-
-static std::string toHex(StringRef Input) {
-  static const char *const LUT = "0123456789ABCDEF";
-  size_t Length = Input.size();
-
-  std::string Output;
-  Output.reserve(2 * Length);
-  for (size_t i = 0; i < Length; ++i) {
-    const unsigned char c = Input[i];
-    Output.push_back(LUT[c >> 4]);
-    Output.push_back(LUT[c & 15]);
-  }
-  return Output;
-}
-
-TEST(raw_sha1_ostreamTest, Basic) {
-  llvm::raw_sha1_ostream Sha1Stream;
-  Sha1Stream << "Hello World!";
-  auto Hash = toHex(Sha1Stream.sha1());
-
-  ASSERT_EQ("2EF7BDE608CE5404E97D5F042F95F89F1C232871", Hash);
-}
-
-TEST(sha1_hash_test, Basic) {
-  ArrayRef<uint8_t> Input((const uint8_t *)"Hello World!", 12);
-  std::array<uint8_t, 20> Vec = SHA1::hash(Input);
-  std::string Hash = toHex({(const char *)Vec.data(), 20});
-  ASSERT_EQ("2EF7BDE608CE5404E97D5F042F95F89F1C232871", Hash);
-}
-
-TEST(sha1_hash_test, Update) {
-  SHA1 sha1;
-  std::string Input = "123456789012345678901234567890";
-  ASSERT_EQ(Input.size(), 30UL);
-  // 3 short updates.
-  sha1.update(Input);
-  sha1.update(Input);
-  sha1.update(Input);
-  // Long update that gets into the optimized loop with prefix/suffix.
-  sha1.update(Input + Input + Input + Input);
-  // 18 bytes buffered now.
-
-  std::string Hash = toHex(sha1.final());
-  ASSERT_EQ("3E4A614101AD84985AB0FE54DC12A6D71551E5AE", Hash);
-}
-
-// Check that getting the intermediate hash in the middle of the stream does
-// not invalidate the final result.
-TEST(raw_sha1_ostreamTest, Intermediate) {
-  llvm::raw_sha1_ostream Sha1Stream;
-  Sha1Stream << "Hello";
-  auto Hash = toHex(Sha1Stream.sha1());
-
-  ASSERT_EQ("F7FF9E8B7BB2E09B70935A5D785E0CC5D9D0ABF0", Hash);
-  Sha1Stream << " World!";
-  Hash = toHex(Sha1Stream.sha1());
-
-  // Compute the non-split hash separately as a reference.
-  llvm::raw_sha1_ostream NonSplitSha1Stream;
-  NonSplitSha1Stream << "Hello World!";
-  auto NonSplitHash = toHex(NonSplitSha1Stream.sha1());
-
-  ASSERT_EQ(NonSplitHash, Hash);
-}
-
-TEST(raw_sha1_ostreamTest, Reset) {
-  llvm::raw_sha1_ostream Sha1Stream;
-  Sha1Stream << "Hello";
-  auto Hash = toHex(Sha1Stream.sha1());
-
-  ASSERT_EQ("F7FF9E8B7BB2E09B70935A5D785E0CC5D9D0ABF0", Hash);
-
-  Sha1Stream.resetHash();
-  Sha1Stream << " World!";
-  Hash = toHex(Sha1Stream.sha1());
-
-  ASSERT_EQ("7447F2A5A42185C8CF91E632789C431830B59067", Hash);
-}

llvm/utils/gn/secondary/llvm/unittests/Support/BUILD.gn

sources = [
     "VersionTupleTest.cpp",
     "VirtualFileSystemTest.cpp",
     "WithColorTest.cpp",
     "YAMLIOTest.cpp",
     "YAMLParserTest.cpp",
     "formatted_raw_ostream_test.cpp",
     "raw_ostream_test.cpp",
     "raw_pwrite_stream_test.cpp",
-    "raw_sha1_ostream_test.cpp",
     "xxhashTest.cpp",
   ]
 }