[llvm-rc] Serialize HTML resources to .res files (serialization, pt 1).

This allows to process HTML resources defined in .rc scripts and output
them to resulting .res files. Additionally, some infrastructure allowing
to output these files is created.

This is the first resource type we can operate on.

Thanks to Nico Weber for his original work in this area.

Differential Revision: reviews.llvm.org/D37283

llvm-svn: 314538

1 files changed, 241 insertions, 0 deletions

diff --git a/llvm/tools/llvm-rc/ResourceFileWriter.cpp b/llvm/tools/llvm-rc/ResourceFileWriter.cpp
new file mode 100644
index 00000000000..642d6ef377c
--- /dev/null
+++ b/llvm/tools/llvm-rc/ResourceFileWriter.cpp
@@ -0,0 +1,241 @@
+//===-- ResourceFileWriter.cpp --------------------------------*- C++-*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This implements the visitor serializing resources to a .res stream.
+//
+//===---------------------------------------------------------------------===//
+
+#include "ResourceFileWriter.h"
+
+#include "llvm/Object/WindowsResource.h"
+#include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/EndianStream.h"
+
+using namespace llvm::support;
+
+// Take an expression returning llvm::Error and forward the error if it exists.
+#define RETURN_IF_ERROR(Expr)                                                  \
+  if (auto Err = (Expr))                                                       \
+    return Err;
+
+namespace llvm {
+namespace rc {
+
+static Error createError(Twine Message,
+                         std::errc Type = std::errc::invalid_argument) {
+  return make_error<StringError>(Message, std::make_error_code(Type));
+}
+
+static Error checkNumberFits(uint32_t Number, size_t MaxBits, Twine FieldName) {
+  assert(1 <= MaxBits && MaxBits <= 32);
+  if (!(Number >> MaxBits))
+    return Error::success();
+  return createError(FieldName + " (" + Twine(Number) + ") does not fit in " +
+                         Twine(MaxBits) + " bits.",
+                     std::errc::value_too_large);
+}
+
+template <typename FitType>
+static Error checkNumberFits(uint32_t Number, Twine FieldName) {
+  return checkNumberFits(Number, sizeof(FitType) * 8, FieldName);
+}
+
+static Error checkIntOrString(IntOrString Value, Twine FieldName) {
+  if (!Value.isInt())
+    return Error::success();
+  return checkNumberFits<uint16_t>(Value.getInt(), FieldName);
+}
+
+static bool stripQuotes(StringRef &Str, bool &IsLongString) {
+  if (!Str.contains('"'))
+    return false;
+
+  // Just take the contents of the string, checking if it's been marked long.
+  IsLongString = Str.startswith_lower("L");
+  if (IsLongString)
+    Str = Str.drop_front();
+
+  bool StripSuccess = Str.consume_front("\"") && Str.consume_back("\"");
+  (void)StripSuccess;
+  assert(StripSuccess && "Strings should be enclosed in quotes.");
+  return true;
+}
+
+// Describes a way to handle '\0' characters when processing the string.
+// rc.exe tool sometimes behaves in a weird way in postprocessing.
+// If the string to be output is equivalent to a C-string (e.g. in MENU
+// titles), string is (predictably) truncated after first 0-byte.
+// When outputting a string table, the behavior is equivalent to appending
+// '\0\0' at the end of the string, and then stripping the string
+// before the first '\0\0' occurrence.
+// Finally, when handling strings in user-defined resources, 0-bytes
+// aren't stripped, nor do they terminate the string.
+
+enum class NullHandlingMethod {
+  UserResource,   // Don't terminate string on '\0'.
+  CutAtNull,      // Terminate string on '\0'.
+  CutAtDoubleNull // Terminate string on '\0\0'; strip final '\0'.
+};
+
+// Parses an identifier or string and returns a processed version of it.
+// For now, it only strips the string boundaries, but TODO:
+//   * Squash "" to a single ".
+//   * Replace the escape sequences with their processed version.
+// For identifiers, this is no-op.
+static Error processString(StringRef Str, NullHandlingMethod NullHandler,
+                           bool &IsLongString, SmallVectorImpl<UTF16> &Result) {
+  assert(NullHandler == NullHandlingMethod::CutAtNull);
+
+  bool IsString = stripQuotes(Str, IsLongString);
+  convertUTF8ToUTF16String(Str, Result);
+
+  if (!IsString) {
+    // It's an identifier if it's not a string. Make all characters uppercase.
+    for (UTF16 &Ch : Result) {
+      assert(Ch <= 0x7F && "We didn't allow identifiers to be non-ASCII");
+      Ch = toupper(Ch);
+    }
+    return Error::success();
+  }
+
+  // We don't process the string contents. Only cut at '\0'.
+
+  for (size_t Pos = 0; Pos < Result.size(); ++Pos)
+    if (Result[Pos] == '\0')
+      Result.resize(Pos);
+
+  return Error::success();
+}
+
+uint64_t ResourceFileWriter::writeObject(const ArrayRef<uint8_t> Data) {
+  uint64_t Result = tell();
+  FS->write((const char *)Data.begin(), Data.size());
+  return Result;
+}
+
+Error ResourceFileWriter::writeCString(StringRef Str, bool WriteTerminator) {
+  SmallVector<UTF16, 128> ProcessedString;
+  bool IsLongString;
+  RETURN_IF_ERROR(processString(Str, NullHandlingMethod::CutAtNull,
+                                IsLongString, ProcessedString));
+  for (auto Ch : ProcessedString)
+    writeInt<uint16_t>(Ch);
+  if (WriteTerminator)
+    writeInt<uint16_t>(0);
+  return Error::success();
+}
+
+Error ResourceFileWriter::writeIdentifier(const IntOrString &Ident) {
+  return writeIntOrString(Ident);
+}
+
+Error ResourceFileWriter::writeIntOrString(const IntOrString &Value) {
+  if (!Value.isInt())
+    return writeCString(Value.getString());
+
+  writeInt<uint16_t>(0xFFFF);
+  writeInt<uint16_t>(Value.getInt());
+  return Error::success();
+}
+
+Error ResourceFileWriter::appendFile(StringRef Filename) {
+  bool IsLong;
+  stripQuotes(Filename, IsLong);
+
+  // Filename path should be relative to the current working directory.
+  // FIXME: docs say so, but reality is more complicated, script
+  // location and include paths must be taken into account.
+  ErrorOr<std::unique_ptr<MemoryBuffer>> File =
+      MemoryBuffer::getFile(Filename, -1, false);
+  if (!File)
+    return make_error<StringError>("Error opening file '" + Filename +
+                                       "': " + File.getError().message(),
+                                   File.getError());
+  *FS << (*File)->getBuffer();
+  return Error::success();
+}
+
+void ResourceFileWriter::padStream(uint64_t Length) {
+  assert(Length > 0);
+  uint64_t Location = tell();
+  Location %= Length;
+  uint64_t Pad = (Length - Location) % Length;
+  for (uint64_t i = 0; i < Pad; ++i)
+    writeInt<uint8_t>(0);
+}
+
+Error ResourceFileWriter::handleError(Error &&Err, const RCResource *Res) {
+  if (Err)
+    return joinErrors(createError("Error in " + Res->getResourceTypeName() +
+                                  " statement (ID " + Twine(Res->ResName) +
+                                  "): "),
+                      std::move(Err));
+  return Error::success();
+}
+
+Error ResourceFileWriter::visitNullResource(const RCResource *Res) {
+  return writeResource(Res, &ResourceFileWriter::writeNullBody);
+}
+
+Error ResourceFileWriter::visitHTMLResource(const RCResource *Res) {
+  return writeResource(Res, &ResourceFileWriter::writeHTMLBody);
+}
+
+Error ResourceFileWriter::visitLanguageStmt(const LanguageResource *Stmt) {
+  RETURN_IF_ERROR(checkNumberFits(Stmt->Lang, 10, "Primary language ID"));
+  RETURN_IF_ERROR(checkNumberFits(Stmt->SubLang, 6, "Sublanguage ID"));
+  ObjectData.LanguageInfo = Stmt->Lang | (Stmt->SubLang << 10);
+  return Error::success();
+}
+
+Error ResourceFileWriter::writeResource(
+    const RCResource *Res,
+    Error (ResourceFileWriter::*BodyWriter)(const RCResource *)) {
+  // We don't know the sizes yet.
+  object::WinResHeaderPrefix HeaderPrefix{ulittle32_t(0U), ulittle32_t(0U)};
+  uint64_t HeaderLoc = writeObject(HeaderPrefix);
+
+  auto ResType = Res->getResourceType();
+  RETURN_IF_ERROR(checkIntOrString(ResType, "Resource type"));
+  RETURN_IF_ERROR(checkIntOrString(Res->ResName, "Resource ID"));
+  RETURN_IF_ERROR(handleError(writeIdentifier(ResType), Res));
+  RETURN_IF_ERROR(handleError(writeIdentifier(Res->ResName), Res));
+
+  padStream(sizeof(uint32_t));
+  object::WinResHeaderSuffix HeaderSuffix{
+      ulittle32_t(0), // DataVersion; seems to always be 0
+      ulittle16_t(Res->getMemoryFlags()), ulittle16_t(ObjectData.LanguageInfo),
+      ulittle32_t(0),  // VersionInfo
+      ulittle32_t(0)}; // Characteristics
+  writeObject(HeaderSuffix);
+
+  uint64_t DataLoc = tell();
+  RETURN_IF_ERROR(handleError((this->*BodyWriter)(Res), Res));
+  // RETURN_IF_ERROR(handleError(dumpResource(Ctx)));
+
+  // Update the sizes.
+  HeaderPrefix.DataSize = tell() - DataLoc;
+  HeaderPrefix.HeaderSize = DataLoc - HeaderLoc;
+  writeObjectAt(HeaderPrefix, HeaderLoc);
+  padStream(sizeof(uint32_t));
+
+  return Error::success();
+}
+
+Error ResourceFileWriter::writeNullBody(const RCResource *) {
+  return Error::success();
+}
+
+Error ResourceFileWriter::writeHTMLBody(const RCResource *Base) {
+  return appendFile(cast<HTMLResource>(Base)->HTMLLoc);
+}
+
+} // namespace rc
+} // namespace llvm