[llvm] [Support] Deprecate one form of support::endian::write (NFC) (PR #156140)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/156140

We have two forms of write:

  template <typename value_type, std::size_t alignment = unaligned>
  inline void write(void *memory, value_type value, endianness endian)

  template <typename value_type, endianness endian, std::size_t alignment>
  inline void write(void *memory, value_type value)

The difference is that endian is a function parameter in the former
but a template parameter in the latter.

This patch streamlines the code by migrating the use of the latter to
the former while deprecating the latter.

I'm planning to do the same for byte_swap and read in follow-up
patches to keep this patch simple and small.


>From 0dd9156885d5caeeb70c1329411cf29651aaa2da Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Sun, 1 Oct 2023 22:12:25 -0700
Subject: [PATCH] [Support] Deprecate one form of support::endian::write (NFC)

We have two forms of write:

  template <typename value_type, std::size_t alignment = unaligned>
  inline void write(void *memory, value_type value, endianness endian)

  template <typename value_type, endianness endian, std::size_t alignment>
  inline void write(void *memory, value_type value)

The difference is that endian is a function parameter in the former
but a template parameter in the latter.

This patch streamlines the code by migrating the use of the latter to
the former while deprecating the latter.

I'm planning to do the same for byte_swap and read in follow-up
patches to keep this patch simple and small.
---
 llvm/include/llvm/Support/Endian.h    | 13 ++++++-------
 llvm/lib/ObjectYAML/GOFFEmitter.cpp   |  4 ++--
 llvm/unittests/Support/EndianTest.cpp | 14 +++++++-------
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/llvm/include/llvm/Support/Endian.h b/llvm/include/llvm/Support/Endian.h
index 02a3194e09784..7eb1d7e8dfe7f 100644
--- a/llvm/include/llvm/Support/Endian.h
+++ b/llvm/include/llvm/Support/Endian.h
@@ -96,9 +96,8 @@ inline void write(void *memory, value_type value, endianness endian) {
          &value, sizeof(value_type));
 }
 
-template<typename value_type,
-         endianness endian,
-         std::size_t alignment>
+template <typename value_type, endianness endian, std::size_t alignment>
+LLVM_DEPRECATED("Pass endian as a function argument instead", "write")
 inline void write(void *memory, value_type value) {
   write<value_type, alignment>(memory, value, endian);
 }
@@ -163,7 +162,7 @@ inline void writeAtBitAlignment(void *memory, value_type value,
                                 uint64_t startBit) {
   assert(startBit < 8);
   if (startBit == 0)
-    write<value_type, endian, alignment>(memory, value);
+    write<value_type, alignment>(memory, value, endian);
   else {
     // Read two values and shift the result into them.
     value_type val[2];
@@ -230,8 +229,8 @@ struct packed_endian_specific_integral {
   operator value_type() const { return value(); }
 
   void operator=(value_type newValue) {
-    endian::write<value_type, endian, alignment>(
-      (void*)Value.buffer, newValue);
+    endian::write<value_type, alignment>((void *)Value.buffer, newValue,
+                                         endian);
   }
 
   packed_endian_specific_integral &operator+=(value_type newValue) {
@@ -268,7 +267,7 @@ struct packed_endian_specific_integral {
     }
 
     void operator=(value_type NewValue) {
-      endian::write<value_type, endian, alignment>(Ptr, NewValue);
+      endian::write<value_type, alignment>(Ptr, NewValue, endian);
     }
 
   private:
diff --git a/llvm/lib/ObjectYAML/GOFFEmitter.cpp b/llvm/lib/ObjectYAML/GOFFEmitter.cpp
index 7e94ac609a030..c26893cfaa720 100644
--- a/llvm/lib/ObjectYAML/GOFFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/GOFFEmitter.cpp
@@ -38,8 +38,8 @@ template <typename ValueType> struct BinaryBeImpl {
 template <typename ValueType>
 raw_ostream &operator<<(raw_ostream &OS, const BinaryBeImpl<ValueType> &BBE) {
   char Buffer[sizeof(BBE.Value)];
-  support::endian::write<ValueType, llvm::endianness::big, support::unaligned>(
-      Buffer, BBE.Value);
+  support::endian::write<ValueType, support::unaligned>(Buffer, BBE.Value,
+                                                        llvm::endianness::big);
   OS.write(Buffer, sizeof(BBE.Value));
   return OS;
 }
diff --git a/llvm/unittests/Support/EndianTest.cpp b/llvm/unittests/Support/EndianTest.cpp
index 59281c0ed5444..c48b7707b7751 100644
--- a/llvm/unittests/Support/EndianTest.cpp
+++ b/llvm/unittests/Support/EndianTest.cpp
@@ -201,26 +201,26 @@ TEST(Endian, WriteBitAligned) {
 
 TEST(Endian, Write) {
   unsigned char data[5];
-  endian::write<int32_t, llvm::endianness::big, unaligned>(data, -1362446643);
+  endian::write<int32_t, unaligned>(data, -1362446643, llvm::endianness::big);
   EXPECT_EQ(data[0], 0xAE);
   EXPECT_EQ(data[1], 0xCA);
   EXPECT_EQ(data[2], 0xB6);
   EXPECT_EQ(data[3], 0xCD);
-  endian::write<int32_t, llvm::endianness::big, unaligned>(data + 1,
-                                                           -1362446643);
+  endian::write<int32_t, unaligned>(data + 1, -1362446643,
+                                    llvm::endianness::big);
   EXPECT_EQ(data[1], 0xAE);
   EXPECT_EQ(data[2], 0xCA);
   EXPECT_EQ(data[3], 0xB6);
   EXPECT_EQ(data[4], 0xCD);
 
-  endian::write<int32_t, llvm::endianness::little, unaligned>(data,
-                                                              -1362446643);
+  endian::write<int32_t, unaligned>(data, -1362446643,
+                                    llvm::endianness::little);
   EXPECT_EQ(data[0], 0xCD);
   EXPECT_EQ(data[1], 0xB6);
   EXPECT_EQ(data[2], 0xCA);
   EXPECT_EQ(data[3], 0xAE);
-  endian::write<int32_t, llvm::endianness::little, unaligned>(data + 1,
-                                                              -1362446643);
+  endian::write<int32_t, unaligned>(data + 1, -1362446643,
+                                    llvm::endianness::little);
   EXPECT_EQ(data[1], 0xCD);
   EXPECT_EQ(data[2], 0xB6);
   EXPECT_EQ(data[3], 0xCA);