Revert "Revert "Revert "Replace trivial use of external rc.exe by writing our own .res file."""

This reverts commit 5fecbbbe5049665d86834cf69d8f75db4f392308.

The initial revert was done in order to prevent ongoing errors on
chromium bots such as CrWinClangLLD.  However, this was done haphazardly
and I didn't realize there were test and compilation failures, so this
revert was reverted.  Now that those have been fixed, we can revert the
revert of the revert.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307226 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/BinaryFormat/COFF.h

@@ -46,12 +46,6 @@ static const char ClGlObjMagic[] = {
     '\xac', '\x9b', '\xd6', '\xb6', '\x22', '\x26', '\x53', '\xc2',
 };
 
-// The signature bytes that start a .res file.
-static const char WinResMagic[] = {
-    '\x00', '\x00', '\x00', '\x00', '\x20', '\x00', '\x00', '\x00',
-    '\xff', '\xff', '\x00', '\x00', '\xff', '\xff', '\x00', '\x00',
-};
-
 // Sizes in bytes of various things in the COFF format.
 enum {
   Header16Size = 20,

include/llvm/Object/WindowsResource.h

@@ -47,44 +47,6 @@ namespace object {
 
 class WindowsResource;
 
-const size_t WIN_RES_MAGIC_SIZE = 16;
-const size_t WIN_RES_NULL_ENTRY_SIZE = 16;
-const uint32_t WIN_RES_HEADER_ALIGNMENT = 4;
-const uint32_t WIN_RES_DATA_ALIGNMENT = 4;
-const uint16_t WIN_RES_PURE_MOVEABLE = 0x0030;
-
-struct WinResHeaderPrefix {
-  support::ulittle32_t DataSize;
-  support::ulittle32_t HeaderSize;
-};
-
-// Type and Name may each either be an integer ID or a string.  This struct is
-// only used in the case where they are both IDs.
-struct WinResIDs {
-  uint16_t TypeFlag;
-  support::ulittle16_t TypeID;
-  uint16_t NameFlag;
-  support::ulittle16_t NameID;
-
-  void setType(uint16_t ID) {
-    TypeFlag = 0xffff;
-    TypeID = ID;
-  }
-
-  void setName(uint16_t ID) {
-    NameFlag = 0xffff;
-    NameID = ID;
-  }
-};
-
-struct WinResHeaderSuffix {
-  support::ulittle32_t DataVersion;
-  support::ulittle16_t MemoryFlags;
-  support::ulittle16_t Language;
-  support::ulittle32_t Version;
-  support::ulittle32_t Characteristics;
-};
-
 class ResourceEntryRef {
 public:
   Error moveNext(bool &End);
@@ -108,6 +70,14 @@ private:
 
   Error loadNext();
 
+  struct HeaderSuffix {
+    support::ulittle32_t DataVersion;
+    support::ulittle16_t MemoryFlags;
+    support::ulittle16_t Language;
+    support::ulittle32_t Version;
+    support::ulittle32_t Characteristics;
+  };
+
   BinaryStreamReader Reader;
   bool IsStringType;
   ArrayRef<UTF16> Type;
@@ -115,7 +85,7 @@ private:
   bool IsStringName;
   ArrayRef<UTF16> Name;
   uint16_t NameID;
-  const WinResHeaderSuffix *Suffix = nullptr;
+  const HeaderSuffix *Suffix = nullptr;
   ArrayRef<uint8_t> Data;
   const WindowsResource *OwningRes = nullptr;
 };

lib/BinaryFormat/Magic.cpp

@@ -51,8 +51,7 @@ file_magic llvm::identify_magic(StringRef Magic) {
       return file_magic::coff_import_library;
     }
     // Windows resource file
-    if (Magic.size() >= sizeof(COFF::WinResMagic) &&
-        memcmp(Magic.data(), COFF::WinResMagic, sizeof(COFF::WinResMagic)) == 0)
+    if (startswith(Magic, "\0\0\0\0\x20\0\0\0\xFF"))
       return file_magic::windows_resource;
     // 0x0000 = COFF unknown machine type
     if (Magic[1] == 0)

lib/Object/WindowsResource.cpp

@@ -36,19 +36,23 @@ const uint32_t MIN_HEADER_SIZE = 7 * sizeof(uint32_t) + 2 * sizeof(uint16_t);
 // 8-byte because it makes everyone happy.
 const uint32_t SECTION_ALIGNMENT = sizeof(uint64_t);
 
+static const size_t ResourceMagicSize = 16;
+
+static const size_t NullEntrySize = 16;
+
 uint32_t WindowsResourceParser::TreeNode::StringCount = 0;
 uint32_t WindowsResourceParser::TreeNode::DataCount = 0;
 
 WindowsResource::WindowsResource(MemoryBufferRef Source)
     : Binary(Binary::ID_WinRes, Source) {
-  size_t LeadingSize = WIN_RES_MAGIC_SIZE + WIN_RES_NULL_ENTRY_SIZE;
+  size_t LeadingSize = ResourceMagicSize + NullEntrySize;
   BBS = BinaryByteStream(Data.getBuffer().drop_front(LeadingSize),
                          support::little);
 }
 
 Expected<std::unique_ptr<WindowsResource>>
 WindowsResource::createWindowsResource(MemoryBufferRef Source) {
-  if (Source.getBufferSize() < WIN_RES_MAGIC_SIZE + WIN_RES_NULL_ENTRY_SIZE)
+  if (Source.getBufferSize() < ResourceMagicSize + NullEntrySize)
     return make_error<GenericBinaryError>(
         "File too small to be a resource file",
         object_error::invalid_file_type);
@@ -101,10 +105,12 @@ static Error readStringOrId(BinaryStreamReader &Reader, uint16_t &ID,
 }
 
 Error ResourceEntryRef::loadNext() {
-  const WinResHeaderPrefix *Prefix;
-  RETURN_IF_ERROR(Reader.readObject(Prefix));
+  uint32_t DataSize;
+  RETURN_IF_ERROR(Reader.readInteger(DataSize));
+  uint32_t HeaderSize;
+  RETURN_IF_ERROR(Reader.readInteger(HeaderSize));
 
-  if (Prefix->HeaderSize < MIN_HEADER_SIZE)
+  if (HeaderSize < MIN_HEADER_SIZE)
     return make_error<GenericBinaryError>("Header size is too small.",
                                           object_error::parse_failed);
 
@@ -112,13 +118,13 @@ Error ResourceEntryRef::loadNext() {
 
   RETURN_IF_ERROR(readStringOrId(Reader, NameID, Name, IsStringName));
 
-  RETURN_IF_ERROR(Reader.padToAlignment(WIN_RES_HEADER_ALIGNMENT));
+  RETURN_IF_ERROR(Reader.padToAlignment(sizeof(uint32_t)));
 
   RETURN_IF_ERROR(Reader.readObject(Suffix));
 
-  RETURN_IF_ERROR(Reader.readArray(Data, Prefix->DataSize));
+  RETURN_IF_ERROR(Reader.readArray(Data, DataSize));
 
-  RETURN_IF_ERROR(Reader.padToAlignment(WIN_RES_DATA_ALIGNMENT));
+  RETURN_IF_ERROR(Reader.padToAlignment(sizeof(uint32_t)));
 
   return Error::success();
 }
@@ -462,6 +468,8 @@ void WindowsResourceCOFFWriter::writeFirstSectionHeader() {
   SectionOneHeader->PointerToLinenumbers = 0;
   SectionOneHeader->NumberOfRelocations = Data.size();
   SectionOneHeader->NumberOfLinenumbers = 0;
+  SectionOneHeader->Characteristics = COFF::IMAGE_SCN_ALIGN_1BYTES;
+  SectionOneHeader->Characteristics += COFF::IMAGE_SCN_CNT_INITIALIZED_DATA;
   SectionOneHeader->Characteristics += COFF::IMAGE_SCN_CNT_INITIALIZED_DATA;
   SectionOneHeader->Characteristics += COFF::IMAGE_SCN_MEM_READ;
 }

unittests/BinaryFormat/TestFileMagic.cpp

@@ -76,8 +76,7 @@ const char macho_dsym_companion[] =
     "\xfe\xed\xfa\xce........\x00\x00\x00\x0a............";
 const char macho_kext_bundle[] =
     "\xfe\xed\xfa\xce........\x00\x00\x00\x0b............";
-const char windows_resource[] =
-    "\x00\x00\x00\x00\x020\x00\x00\x00\xff\xff\x00\x00\xff\xff\x00\x00";
+const char windows_resource[] = "\x00\x00\x00\x00\x020\x00\x00\x00\xff";
 const char macho_dynamically_linked_shared_lib_stub[] =
     "\xfe\xed\xfa\xce........\x00\x00\x00\x09............";