[llvm-rc] Add a GNU windres-like frontend to llvm-rc

This primarily parses a different set of options and invokes the same
resource compiler as llvm-rc normally. Additionally, it can convert
directly to an object file (which in MSVC style setups is done with the
separate cvtres tool, or by the linker).

(GNU windres also supports other conversions; from coff object file back
to .res, and from .res or object file back to .rc form; that's not yet
implemented.)

The other bigger complication lies in being able to imply or pass the
intended target triple, to let clang find the corresponding mingw sysroot
for finding include files, and for specifying the default output object
machine format.

It can be implied from the tool triple prefix, like
`<triple>-[llvm-]windres` or picked up from the windres option e.g.
`-F pe-x86-64`. In GNU windres, that option takes BFD style format names
such as pe-i386 or pe-x86-64. As libbfd in binutils doesn't support
Windows on ARM, there's no such canonical name for the ARM targets.
Therefore, as an LLVM specific extension, this option is extended to
allow passing full triples, too.

Differential Revision: https://reviews.llvm.org/D100756

clang/test/CMakeLists.txt

@@ -125,6 +125,7 @@ if( NOT CLANG_BUILT_STANDALONE )
     llvm-readobj
     llvm-strip
     llvm-symbolizer
+    llvm-windres
     opt
     split-file
     yaml2obj

clang/test/Preprocessor/Inputs/llvm-windres.h

@@ -0,0 +1,10 @@
+#ifndef RC_INVOKED
+#error RC_INVOKED not defined
+#endif
+#ifndef _WIN32
+#error _WIN32 not defined
+#endif
+#ifndef __MINGW32__
+#error __MINGW32__ not defined
+#endif
+#define MY_ID 42

clang/test/Preprocessor/llvm-windres.rc

@@ -0,0 +1,8 @@
+// RUN: llvm-windres -I%p/Inputs %s %t.res
+// RUN: llvm-readobj %t.res | FileCheck %s
+// CHECK: Resource type (int): RCDATA (ID 10)
+// CHECK: Resource name (int): 42
+#include "llvm-windres.h"
+MY_ID RCDATA {
+  "a long string of data"
+}

llvm/test/CMakeLists.txt

@@ -117,6 +117,7 @@ set(LLVM_TEST_DEPENDS
           llvm-symbolizer
           llvm-tblgen
           llvm-undname
+          llvm-windres
           llvm-xray
           not
           obj2yaml

llvm/test/lit.cfg.py

@@ -163,7 +163,8 @@ tools.extend([
     'llvm-modextract', 'llvm-nm', 'llvm-objcopy', 'llvm-objdump', 'llvm-otool',
     'llvm-pdbutil', 'llvm-profdata', 'llvm-profgen', 'llvm-ranlib', 'llvm-rc', 'llvm-readelf',
     'llvm-readobj', 'llvm-rtdyld', 'llvm-size', 'llvm-split', 'llvm-strings',
-    'llvm-strip', 'llvm-tblgen', 'llvm-undname', 'llvm-c-test', 'llvm-cxxfilt',
+    'llvm-strip', 'llvm-tblgen', 'llvm-undname', 'llvm-windres',
+    'llvm-c-test', 'llvm-cxxfilt',
     'llvm-xray', 'yaml2obj', 'obj2yaml', 'yaml-bench', 'verify-uselistorder',
     'bugpoint', 'llc', 'llvm-symbolizer', 'opt', 'sancov', 'sanstats'])
 

llvm/test/tools/llvm-rc/codepage.test

@@ -1,5 +1,9 @@
 ; RUN: llvm-rc -no-preprocess /C 65001 /FO %t.utf8.res -- %p/Inputs/utf8.rc
 ; RUN: llvm-readobj %t.utf8.res | FileCheck %s --check-prefix=UTF8
+; RUN: llvm-windres --no-preprocess -c 65001 %p/Inputs/utf8.rc %t.utf8.res
+; RUN: llvm-readobj %t.utf8.res | FileCheck %s --check-prefix=UTF8
+; RUN: llvm-windres --no-preprocess --codepage 65001 %p/Inputs/utf8.rc %t.utf8.res
+; RUN: llvm-readobj %t.utf8.res | FileCheck %s --check-prefix=UTF8
 
 ; UTF8:      Resource type (int): STRINGTABLE (ID 6)
 ; UTF8-NEXT: Resource name (int): 1
@@ -24,6 +28,8 @@
 
 ; RUN: llvm-rc -no-preprocess /C 1252 /FO %t.cp1252.res -- %p/Inputs/cp1252.rc
 ; RUN: llvm-readobj %t.cp1252.res | FileCheck %s --check-prefix=CP1252
+; RUN: llvm-windres --no-preprocess -c 1252 %p/Inputs/cp1252.rc %t.cp1252.res
+; RUN: llvm-readobj %t.cp1252.res | FileCheck %s --check-prefix=CP1252
 
 ; CP1252:      Resource type (int): STRINGTABLE (ID 6)
 ; CP1252-NEXT: Resource name (int): 1

llvm/test/tools/llvm-rc/language.test

@@ -2,6 +2,10 @@
 ; RUN: llvm-readobj %t.res | FileCheck %s
 ; RUN: llvm-rc -no-preprocess /l40A /FO %t.res -- %p/Inputs/language.rc
 ; RUN: llvm-readobj %t.res | FileCheck %s
+; RUN: llvm-windres --no-preprocess -l 40A %p/Inputs/language.rc %t.res
+; RUN: llvm-readobj %t.res | FileCheck %s
+; RUN: llvm-windres --no-preprocess --language 40A %p/Inputs/language.rc %t.res
+; RUN: llvm-readobj %t.res | FileCheck %s
 
 ; CHECK:      Resource name (int): 1
 ; CHECK-NEXT: Data version:

llvm/test/tools/llvm-rc/windres-format.test

@@ -0,0 +1,40 @@
+; Check that the various input/output formats (rc/res/coff) are implied
+; from file suffixes.
+
+; RUN: rm -f %t.res
+; RUN: llvm-windres --no-preprocess %p/Inputs/tag-stringtable-basic.rc %t.res
+; RUN: llvm-readobj %t.res | FileCheck %s --check-prefix=CHECK-RES
+
+; RUN: rm -f %t.o
+; RUN: llvm-windres --no-preprocess -F pe-x86-64 %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefix=CHECK-OBJ
+
+; RUN: rm -f %t.obj
+; RUN: llvm-windres -F pe-x86-64 %t.res %t.obj
+; RUN: llvm-readobj --coff-resources %t.obj | FileCheck %s --check-prefix=CHECK-OBJ
+
+; Check that we can specify the input/output file types explicitly.
+; Also check options for specifying the input/output file names.
+
+; RUN: cat %p/Inputs/tag-stringtable-basic.rc > %t-anonymous
+; RUN: rm -f %t-anonymous2
+; RUN: llvm-windres --no-preprocess -O res -J rc -o %t-anonymous2 -i %t-anonymous
+; RUN: llvm-readobj %t-anonymous2 | FileCheck %s --check-prefix=CHECK-RES
+
+; RUN: rm -f %t-anonymous3
+; RUN: llvm-windres -F pe-x86-64 -J res -O coff -i%t-anonymous2 -o%t-anonymous3
+; RUN: llvm-readobj --coff-resources %t-anonymous3 | FileCheck %s --check-prefix=CHECK-OBJ
+
+; CHECK-RES: Resource type (int): STRINGTABLE
+
+; CHECK-OBJ: Format: COFF-x86-64
+; CHECK-OBJ: Resources [
+; CHECK-OBJ:   Total Number of Resources:
+
+; Check for format conversions that currently aren't supported.
+
+; RUN: not llvm-windres -F pe-x86-64 -J res -O rc -i%t-anonymous2 -o%t-anonymous 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR-OUTPUT
+; RUN: not llvm-windres -F pe-x86-64 -J coff -O res -i%t-anonymous3 -o%t-anonymous2 2>&1 | FileCheck %s --check-prefix=CHECK-ERROR-INPUT
+
+; CHECK-ERROR-OUTPUT: Unsupported output format
+; CHECK-ERROR-INPUT: Unsupported input format

llvm/test/tools/llvm-rc/windres-prefix.test

@@ -0,0 +1,18 @@
+; REQUIRES: shell
+
+; RUN: rm -rf %t && mkdir %t
+
+; Check that a triple prefix on the executable gets picked up as target triple.
+
+; RUN: ln -fs $(which llvm-windres) %t/aarch64-w64-mingw32-windres
+; RUN: %t/aarch64-w64-mingw32-windres -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-PREPROC
+; CHECK-PREPROC: "clang" "--driver-mode=gcc" "-target" "aarch64-w64-mingw32"
+
+; Check that the triple prefix also affects the output object file type.
+
+; RUN: %t/aarch64-w64-mingw32-windres --no-preprocess %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefix=CHECK-OBJ
+
+; CHECK-OBJ: Format: COFF-ARM64
+; CHECK-OBJ: Resources [
+; CHECK-OBJ:   Total Number of Resources:

llvm/test/tools/llvm-rc/windres-preproc.test

@@ -0,0 +1,4 @@
+; RUN: llvm-windres -### --include-dir %p/incdir1 --include %p/incdir2 "-DFOO1=\\\"foo bar\\\"" -UFOO2 -D FOO3 --preprocessor-arg "-DFOO4=\\\"baz baz\\\"" %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK1
+; CHECK1: {{^}} "clang" "--driver-mode=gcc" "-target" "{{.*}}-w64-mingw32" "-E" "-xc" "-DRC_INVOKED" "{{.*}}empty.rc" "-o" "{{.*}}preproc-{{.*}}.rc" "-I" "{{.*}}incdir1" "-I" "{{.*}}incdir2" "-D" "FOO1=\"foo bar\"" "-U" "FOO2" "-D" "FOO3" "-DFOO4=\"baz baz\""{{$}}
+; RUN: llvm-windres -### --preprocessor "i686-w64-mingw32-gcc -E -DFOO=\\\"foo\\ bar\\\"" %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK2
+; CHECK2: {{^}} "i686-w64-mingw32-gcc" "-E" "-DFOO=\"foo bar\"" "{{.*}}empty.rc" "-o" "{{.*}}preproc-{{.*}}.rc"{{$}}

llvm/test/tools/llvm-rc/windres-target.test

@@ -0,0 +1,34 @@
+; Check handling of the -F/--target option for setting a specific BFD
+; target name.
+
+; RUN: llvm-windres -F pe-i386 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-I686
+; RUN: llvm-windres -Fpe-i386 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-I686
+; CHECK-I686: "clang" "--driver-mode=gcc" "-target" "i686-w64-mingw32"
+; RUN: llvm-windres --target pe-x86-64 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-X86-64
+; RUN: llvm-windres --target=pe-x86-64 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-X86-64
+; CHECK-X86-64: "clang" "--driver-mode=gcc" "-target" "x86_64-w64-mingw32"
+
+; LLVM windres specific: Check that we can pass a full triple via the
+; -F/--target option, if it doesn't match the BFD target names.
+
+; RUN: llvm-windres -F armv7-w64-mingw32 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-ARMV7
+; RUN: llvm-windres --target armv7-w64-mingw32 -### %p/Inputs/empty.rc %t.res | FileCheck %s --check-prefix=CHECK-ARMV7
+; CHECK-ARMV7: "clang" "--driver-mode=gcc" "-target" "armv7-w64-mingw32"
+
+; Check the actual written object types.
+
+; RUN: llvm-windres --no-preprocess -F i686-w64-mingw32 %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefixes=CHECK-OBJ,CHECK-OBJ-I686
+; RUN: llvm-windres --no-preprocess -F x86_64-w64-mingw32 %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefixes=CHECK-OBJ,CHECK-OBJ-X86-64
+; RUN: llvm-windres --no-preprocess -F armv7-w64-mingw32 %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefixes=CHECK-OBJ,CHECK-OBJ-ARMV7
+; RUN: llvm-windres --no-preprocess -F aarch64-w64-mingw32 %p/Inputs/tag-stringtable-basic.rc %t.o
+; RUN: llvm-readobj --coff-resources %t.o | FileCheck %s --check-prefixes=CHECK-OBJ,CHECK-OBJ-AARCH64
+
+; CHECK-OBJ-I686: Format: COFF-i386
+; CHECK-OBJ-X86-64: Format: COFF-x86-64
+; CHECK-OBJ-ARMV7: Format: COFF-ARM{{$}}
+; CHECK-OBJ-AARCH64: Format: COFF-ARM64
+; CHECK-OBJ: Resources [
+; CHECK-OBJ:   Total Number of Resources:

llvm/test/tools/llvm-rc/windres-version.test

@@ -0,0 +1,6 @@
+; RUN: llvm-windres --version | FileCheck %s
+
+; Check that the printed version string contains the words "GNU windres",
+; which some build systems look for.
+
+; CHECK: GNU windres

llvm/tools/llvm-rc/CMakeLists.txt

@@ -1,12 +1,16 @@
 set(LLVM_LINK_COMPONENTS
+  Object
   Option
   Support
   )
 
 set(LLVM_TARGET_DEFINITIONS Opts.td)
-
 tablegen(LLVM Opts.inc -gen-opt-parser-defs)
-add_public_tablegen_target(RcTableGen)
+add_public_tablegen_target(RcOptsTableGen)
+
+set(LLVM_TARGET_DEFINITIONS WindresOpts.td)
+tablegen(LLVM WindresOpts.inc -gen-opt-parser-defs)
+add_public_tablegen_target(WindresOptsTableGen)
 
 add_llvm_tool(llvm-rc
   llvm-rc.cpp
@@ -16,3 +20,9 @@ add_llvm_tool(llvm-rc
   ResourceScriptStmt.cpp
   ResourceScriptToken.cpp
   )
+
+add_llvm_tool_symlink(llvm-windres llvm-rc)
+
+if(LLVM_INSTALL_BINUTILS_SYMLINKS)
+  add_llvm_tool_symlink(windres llvm-rc)
+endif()

llvm/tools/llvm-rc/WindresOpts.td

@@ -0,0 +1,62 @@
+include "llvm/Option/OptParser.td"
+
+multiclass Long<string name, string help> {
+  def NAME: Separate<["--"], name>;
+  def NAME # _eq: Joined<["--"], name # "=">, Alias<!cast<Separate>(NAME)>,
+    HelpText<help>;
+}
+
+multiclass LongAlias<string name, Option orig> {
+  def NAME: Separate<["--"], name>, Alias<orig>;
+  def NAME # _eq: Joined<["--"], name # "=">, Alias<orig>;
+}
+
+multiclass LongShort<string short, string long, string help> {
+  def NAME: Separate<["--"], long>;
+  def NAME # _eq: Joined<["--"], long # "=">, Alias<!cast<Separate>(NAME)>,
+    HelpText<help>;
+  def NAME # _short: JoinedOrSeparate<["-"], short>, Alias<!cast<Separate>(NAME)>;
+}
+
+multiclass F<string short, string long, string help> {
+  def NAME: Flag<["-"], short>;
+  def NAME # _long: Flag<["--"], long>, Alias<!cast<Flag>(NAME)>,
+    HelpText<help>;
+}
+
+defm input : LongShort<"i", "input", "Input file">;
+
+defm output : LongShort<"o", "output", "Output file">;
+
+defm input_format : LongShort<"J", "input-format", "Input format">;
+
+defm output_format : LongShort<"O", "output-format", "Output format">;
+
+defm preprocessor : Long<"preprocessor", "Custom preprocessor command">;
+defm preprocessor_arg : Long<"preprocessor-arg", "Preprocessor command argument">;
+
+defm target : LongShort<"F", "target", "Target BFD format name">;
+
+defm include_dir : LongShort<"I", "include-dir", "Include directory">;
+defm include_alias : LongAlias<"include", include_dir>;
+
+defm define : LongShort<"D", "define", "Define to pass to the preprocessor">;
+
+defm undef : LongShort<"U", "undefine", "Undefine to pass to the preprocessor">;
+
+defm codepage : LongShort<"c", "codepage", "Default codepage to use">;
+
+defm language : LongShort<"l", "language", "Default language to use (0x0-0xffff)">;
+
+defm verbose : F<"v", "verbose", "Enable verbose output">;
+defm version : F<"V", "version", "Display version">;
+
+defm help : F<"h", "help", "Display this message and exit">;
+
+// Print (but do not run) the commands to run for preprocessing
+def _HASH_HASH_HASH : Flag<["-"], "###">;
+
+def no_preprocess : Flag<["--"], "no-preprocess">;
+
+// Unimplemented options for compatibility
+def use_temp_file: Flag<["--"], "use-temp-file">;

llvm/tools/llvm-rc/llvm-rc.cpp

@@ -18,8 +18,10 @@
 #include "ResourceScriptToken.h"
 
 #include "llvm/ADT/Triple.h"
+#include "llvm/Object/WindowsResource.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FileUtilities.h"
@@ -75,8 +77,39 @@ public:
   RcOptTable() : OptTable(InfoTable, /* IgnoreCase = */ true) {}
 };
 
+enum Windres_ID {
+  WINDRES_INVALID = 0, // This is not a correct option ID.
+#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
+               HELPTEXT, METAVAR, VALUES)                                      \
+  WINDRES_##ID,
+#include "WindresOpts.inc"
+#undef OPTION
+};
+
+#define PREFIX(NAME, VALUE) const char *const WINDRES_##NAME[] = VALUE;
+#include "WindresOpts.inc"
+#undef PREFIX
+
+static const opt::OptTable::Info WindresInfoTable[] = {
+#define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,  \
+               HELPTEXT, METAVAR, VALUES)                                      \
+  {                                                                            \
+      WINDRES_##PREFIX, NAME,         HELPTEXT,                                \
+      METAVAR,          WINDRES_##ID, opt::Option::KIND##Class,                \
+      PARAM,            FLAGS,        WINDRES_##GROUP,                         \
+      WINDRES_##ALIAS,  ALIASARGS,    VALUES},
+#include "WindresOpts.inc"
+#undef OPTION
+};
+
+class WindresOptTable : public opt::OptTable {
+public:
+  WindresOptTable() : OptTable(WindresInfoTable, /* IgnoreCase = */ false) {}
+};
+
 static ExitOnError ExitOnErr;
 static FileRemover TempPreprocFile;
+static FileRemover TempResFile;
 
 LLVM_ATTRIBUTE_NORETURN static void fatalError(const Twine &Message) {
   errs() << Message << "\n";
@@ -112,9 +145,8 @@ ErrorOr<std::string> findClang(const char *Argv0) {
   return Path;
 }
 
-std::string getClangClTriple() {
+Triple::ArchType getDefaultArch(Triple::ArchType Arch) {
-  Triple T(sys::getDefaultTargetTriple());
+  switch (Arch) {
-  switch (T.getArch()) {
   case Triple::x86:
   case Triple::x86_64:
   case Triple::arm:
@@ -122,13 +154,17 @@ std::string getClangClTriple() {
   case Triple::aarch64:
     // These work properly with the clang driver, setting the expected
     // defines such as _WIN32 etc.
-    break;
+    return Arch;
   default:
     // Other archs aren't set up for use with windows as target OS, (clang
     // doesn't define e.g. _WIN32 etc), so set a reasonable default arch.
-    T.setArch(Triple::x86_64);
+    return Triple::x86_64;
-    break;
   }
+}
+
+std::string getClangClTriple() {
+  Triple T(sys::getDefaultTargetTriple());
+  T.setArch(getDefaultArch(T.getArch()));
   T.setOS(Triple::Win32);
   T.setVendor(Triple::PC);
   T.setEnvironment(Triple::MSVC);
@@ -136,10 +172,44 @@ std::string getClangClTriple() {
   return T.str();
 }
 
-bool preprocess(StringRef Src, StringRef Dst, opt::InputArgList &InputArgs,
+std::string getMingwTriple() {
+  Triple T(sys::getDefaultTargetTriple());
+  T.setArch(getDefaultArch(T.getArch()));
+  if (T.isWindowsGNUEnvironment())
+    return T.str();
+  // Write out the literal form of the vendor/env here, instead of
+  // constructing them with enum values (which end up with them in
+  // normalized form). The literal form of the triple can matter for
+  // finding include files.
+  return (Twine(T.getArchName()) + "-w64-mingw32").str();
+}
+
+enum Format { Rc, Res, Coff, Unknown };
+
+struct RcOptions {
+  bool Preprocess = true;
+  bool PrintCmdAndExit = false;
+  std::string Triple;
+  std::vector<std::string> PreprocessCmd;
+  std::vector<std::string> PreprocessArgs;
+
+  std::string InputFile;
+  Format InputFormat = Rc;
+  std::string OutputFile;
+  Format OutputFormat = Res;
+
+  bool BeVerbose = false;
+  WriterParams Params;
+  bool AppendNull = false;
+  bool IsDryRun = false;
+  // Set the default language; choose en-US arbitrarily.
+  unsigned LangId = (/*PrimaryLangId*/ 0x09) | (/*SubLangId*/ 0x01 << 10);
+};
+
+bool preprocess(StringRef Src, StringRef Dst, const RcOptions &Opts,
                 const char *Argv0) {
   std::string Clang;
-  if (InputArgs.hasArg(OPT__HASH_HASH_HASH)) {
+  if (Opts.PrintCmdAndExit) {
     Clang = "clang";
   } else {
     ErrorOr<std::string> ClangOrErr = findClang(Argv0);
@@ -154,40 +224,27 @@ bool preprocess(StringRef Src, StringRef Dst, opt::InputArgList &InputArgs,
       return false;
     }
   }
-  std::string PreprocTriple = getClangClTriple();
 
   SmallVector<StringRef, 8> Args = {
-      Clang, "--driver-mode=gcc", "-target", PreprocTriple, "-E",
+      Clang, "--driver-mode=gcc", "-target", Opts.Triple, "-E",
-      "-xc", "-DRC_INVOKED",      Src,       "-o",          Dst};
+      "-xc", "-DRC_INVOKED"};
-  if (InputArgs.hasArg(OPT_noinclude)) {
+  if (!Opts.PreprocessCmd.empty()) {
-#ifdef _WIN32
+    Args.clear();
-    ::_putenv("INCLUDE=");
+    for (const auto &S : Opts.PreprocessCmd)
-#else
+      Args.push_back(S);
-    ::unsetenv("INCLUDE");
-#endif
   }
-  for (const auto *Arg :
+  Args.push_back(Src);
-       InputArgs.filtered(OPT_includepath, OPT_define, OPT_undef)) {
+  Args.push_back("-o");
-    switch (Arg->getOption().getID()) {
+  Args.push_back(Dst);
-    case OPT_includepath:
+  for (const auto &S : Opts.PreprocessArgs)
-      Args.push_back("-I");
+    Args.push_back(S);
-      break;
+  if (Opts.PrintCmdAndExit || Opts.BeVerbose) {
-    case OPT_define:
-      Args.push_back("-D");
-      break;
-    case OPT_undef:
-      Args.push_back("-U");
-      break;
-    }
-    Args.push_back(Arg->getValue());
-  }
-  if (InputArgs.hasArg(OPT__HASH_HASH_HASH) || InputArgs.hasArg(OPT_verbose)) {
     for (const auto &A : Args) {
       outs() << " ";
-      sys::printArg(outs(), A, InputArgs.hasArg(OPT__HASH_HASH_HASH));
+      sys::printArg(outs(), A, Opts.PrintCmdAndExit);
     }
     outs() << "\n";
-    if (InputArgs.hasArg(OPT__HASH_HASH_HASH))
+    if (Opts.PrintCmdAndExit)
       exit(0);
   }
   // The llvm Support classes don't handle reading from stdout of a child
@@ -199,40 +256,340 @@ bool preprocess(StringRef Src, StringRef Dst, opt::InputArgList &InputArgs,
   return true;
 }
 
-} // anonymous namespace
+static bool consume_back_lower(StringRef &S, const char *Str) {
+  if (!S.endswith_lower(Str))
+    return false;
+  S = S.drop_back(strlen(Str));
+  return true;
+}
 
-int main(int Argc, const char **Argv) {
+static std::pair<bool, std::string> isWindres(llvm::StringRef Argv0) {
-  InitLLVM X(Argc, Argv);
+  StringRef ProgName = llvm::sys::path::stem(Argv0);
-  ExitOnErr.setBanner("llvm-rc: ");
+  // x86_64-w64-mingw32-windres -> x86_64-w64-mingw32, windres
+  // llvm-rc -> "", llvm-rc
+  // aarch64-w64-mingw32-llvm-windres-10.exe -> aarch64-w64-mingw32, llvm-windres
+  ProgName = ProgName.rtrim("0123456789.-");
+  if (!consume_back_lower(ProgName, "windres"))
+    return std::make_pair<bool, std::string>(false, "");
+  consume_back_lower(ProgName, "llvm-");
+  consume_back_lower(ProgName, "-");
+  return std::make_pair<bool, std::string>(true, ProgName.str());
+}
 
-  RcOptTable T;
+Format parseFormat(StringRef S) {
+  Format F = StringSwitch<Format>(S.lower())
+                 .Case("rc", Rc)
+                 .Case("res", Res)
+                 .Case("coff", Coff)
+                 .Default(Unknown);
+  if (F == Unknown)
+    fatalError("Unable to parse '" + Twine(S) + "' as a format");
+  return F;
+}
+
+void deduceFormat(Format &Dest, StringRef File) {
+  Format F = StringSwitch<Format>(sys::path::extension(File.lower()))
+                 .Case(".rc", Rc)
+                 .Case(".res", Res)
+                 .Case(".o", Coff)
+                 .Case(".obj", Coff)
+                 .Default(Unknown);
+  if (F != Unknown)
+    Dest = F;
+}
+
+std::string unescape(StringRef S) {
+  std::string Out;
+  Out.reserve(S.size());
+  for (int I = 0, E = S.size(); I < E; I++) {
+    if (S[I] == '\\') {
+      if (I + 1 < E)
+        Out.push_back(S[++I]);
+      else
+        fatalError("Unterminated escape");
+      continue;
+    }
+    Out.push_back(S[I]);
+  }
+  return Out;
+}
+
+std::vector<std::string> unescapeSplit(StringRef S) {
+  std::vector<std::string> OutArgs;
+  std::string Out;
+  bool InQuote = false;
+  for (int I = 0, E = S.size(); I < E; I++) {
+    if (S[I] == '\\') {
+      if (I + 1 < E)
+        Out.push_back(S[++I]);
+      else
+        fatalError("Unterminated escape");
+      continue;
+    }
+    if (S[I] == '"') {
+      InQuote = !InQuote;
+      continue;
+    }
+    if (S[I] == ' ' && !InQuote) {
+      OutArgs.push_back(Out);
+      Out.clear();
+      continue;
+    }
+    Out.push_back(S[I]);
+  }
+  if (InQuote)
+    fatalError("Unterminated quote");
+  if (!Out.empty())
+    OutArgs.push_back(Out);
+  return OutArgs;
+}
+
+RcOptions parseWindresOptions(ArrayRef<const char *> ArgsArr,
+                              ArrayRef<const char *> InputArgsArray,
+                              std::string Prefix) {
+  WindresOptTable T;
+  RcOptions Opts;
   unsigned MAI, MAC;
-  const char **DashDash = std::find_if(
+  opt::InputArgList InputArgs = T.ParseArgs(ArgsArr, MAI, MAC);
-      Argv + 1, Argv + Argc, [](StringRef Str) { return Str == "--"; });
-  ArrayRef<const char *> ArgsArr = makeArrayRef(Argv + 1, DashDash);
 
+  // The tool prints nothing when invoked with no command-line arguments.
+  if (InputArgs.hasArg(WINDRES_help)) {
+    T.PrintHelp(outs(), "windres [options] file...",
+                "LLVM windres (GNU windres compatible)", false, true);
+    exit(0);
+  }
+
+  if (InputArgs.hasArg(WINDRES_version)) {
+    outs() << "llvm-windres, compatible with GNU windres\n";
+    cl::PrintVersionMessage();
+    exit(0);
+  }
+
+  std::vector<std::string> FileArgs = InputArgs.getAllArgValues(WINDRES_INPUT);
+  FileArgs.insert(FileArgs.end(), InputArgsArray.begin(), InputArgsArray.end());
+
+  if (InputArgs.hasArg(WINDRES_input)) {
+    Opts.InputFile = InputArgs.getLastArgValue(WINDRES_input).str();
+  } else if (!FileArgs.empty()) {
+    Opts.InputFile = FileArgs.front();
+    FileArgs.erase(FileArgs.begin());
+  } else {
+    // TODO: GNU windres takes input on stdin in this case.
+    fatalError("Missing input file");
+  }
+
+  if (InputArgs.hasArg(WINDRES_output)) {
+    Opts.OutputFile = InputArgs.getLastArgValue(WINDRES_output).str();
+  } else if (!FileArgs.empty()) {
+    Opts.OutputFile = FileArgs.front();
+    FileArgs.erase(FileArgs.begin());
+  } else {
+    // TODO: GNU windres writes output in rc form to stdout in this case.
+    fatalError("Missing output file");
+  }
+
+  if (InputArgs.hasArg(WINDRES_input_format)) {
+    Opts.InputFormat =
+        parseFormat(InputArgs.getLastArgValue(WINDRES_input_format));
+  } else {
+    deduceFormat(Opts.InputFormat, Opts.InputFile);
+  }
+  if (Opts.InputFormat == Coff)
+    fatalError("Unsupported input format");
+
+  if (InputArgs.hasArg(WINDRES_output_format)) {
+    Opts.OutputFormat =
+        parseFormat(InputArgs.getLastArgValue(WINDRES_output_format));
+  } else {
+    // The default in windres differs from the default in RcOptions
+    Opts.OutputFormat = Coff;
+    deduceFormat(Opts.OutputFormat, Opts.OutputFile);
+  }
+  if (Opts.OutputFormat == Rc)
+    fatalError("Unsupported output format");
+  if (Opts.InputFormat == Opts.OutputFormat) {
+    outs() << "Nothing to do.\n";
+    exit(0);
+  }
+
+  Opts.PrintCmdAndExit = InputArgs.hasArg(WINDRES__HASH_HASH_HASH);
+  Opts.Preprocess = !InputArgs.hasArg(WINDRES_no_preprocess);
+  Triple TT(Prefix);
+  if (InputArgs.hasArg(WINDRES_target)) {
+    StringRef Value = InputArgs.getLastArgValue(WINDRES_target);
+    if (Value == "pe-i386")
+      Opts.Triple = "i686-w64-mingw32";
+    else if (Value == "pe-x86-64")
+      Opts.Triple = "x86_64-w64-mingw32";
+    else
+      // Implicit extension; if the --target value isn't one of the known
+      // BFD targets, allow setting the full triple string via this instead.
+      Opts.Triple = Value.str();
+  } else if (TT.getArch() != Triple::UnknownArch)
+    Opts.Triple = Prefix;
+  else
+    Opts.Triple = getMingwTriple();
+
+  for (const auto *Arg :
+       InputArgs.filtered(WINDRES_include_dir, WINDRES_define, WINDRES_undef,
+                          WINDRES_preprocessor_arg)) {
+    // GNU windres passes the arguments almost as-is on to popen() (it only
+    // backslash escapes spaces in the arguments), where a shell would
+    // unescape backslash escapes for quotes and similar. This means that
+    // when calling GNU windres, callers need to double escape chars like
+    // quotes, e.g. as -DSTRING=\\\"1.2.3\\\".
+    //
+    // Exactly how the arguments are interpreted depends on the platform
+    // though - but the cases where this matters (where callers would have
+    // done this double escaping) probably is confined to cases like these
+    // quoted string defines, and those happen to work the same across unix
+    // and windows.
+    std::string Unescaped = unescape(Arg->getValue());
+    switch (Arg->getOption().getID()) {
+    case WINDRES_include_dir:
+      // Technically, these are handled the same way as e.g. defines, but
+      // the way we consistently unescape the unix way breaks windows paths
+      // with single backslashes. Alternatively, our unescape function would
+      // need to mimic the platform specific command line parsing/unescaping
+      // logic.
+      Opts.Params.Include.push_back(Arg->getValue());
+      Opts.PreprocessArgs.push_back("-I");
+      Opts.PreprocessArgs.push_back(Arg->getValue());
+      break;
+    case WINDRES_define:
+      Opts.PreprocessArgs.push_back("-D");
+      Opts.PreprocessArgs.push_back(Unescaped);
+      break;
+    case WINDRES_undef:
+      Opts.PreprocessArgs.push_back("-U");
+      Opts.PreprocessArgs.push_back(Unescaped);
+      break;
+    case WINDRES_preprocessor_arg:
+      Opts.PreprocessArgs.push_back(Unescaped);
+      break;
+    }
+  }
+  if (InputArgs.hasArg(WINDRES_preprocessor))
+    Opts.PreprocessCmd =
+        unescapeSplit(InputArgs.getLastArgValue(WINDRES_preprocessor));
+
+  Opts.Params.CodePage = CpWin1252; // Different default
+  if (InputArgs.hasArg(WINDRES_codepage)) {
+    if (InputArgs.getLastArgValue(WINDRES_codepage)
+            .getAsInteger(10, Opts.Params.CodePage))
+      fatalError("Invalid code page: " +
+                 InputArgs.getLastArgValue(WINDRES_codepage));
+  }
+  if (InputArgs.hasArg(WINDRES_language)) {
+    if (InputArgs.getLastArgValue(WINDRES_language)
+            .getAsInteger(16, Opts.LangId))
+      fatalError("Invalid language id: " +
+                 InputArgs.getLastArgValue(WINDRES_language));
+  }
+
+  Opts.BeVerbose = InputArgs.hasArg(WINDRES_verbose);
+
+  return Opts;
+}
+
+RcOptions parseRcOptions(ArrayRef<const char *> ArgsArr,
+                         ArrayRef<const char *> InputArgsArray) {
+  RcOptTable T;
+  RcOptions Opts;
+  unsigned MAI, MAC;
   opt::InputArgList InputArgs = T.ParseArgs(ArgsArr, MAI, MAC);
 
   // The tool prints nothing when invoked with no command-line arguments.
   if (InputArgs.hasArg(OPT_help)) {
     T.PrintHelp(outs(), "rc [options] file...", "Resource Converter", false);
-    return 0;
+    exit(0);
   }
 
-  const bool BeVerbose = InputArgs.hasArg(OPT_verbose);
-
   std::vector<std::string> InArgsInfo = InputArgs.getAllArgValues(OPT_INPUT);
-  if (DashDash != Argv + Argc)
+  InArgsInfo.insert(InArgsInfo.end(), InputArgsArray.begin(),
-    InArgsInfo.insert(InArgsInfo.end(), DashDash + 1, Argv + Argc);
+                    InputArgsArray.end());
   if (InArgsInfo.size() != 1) {
     fatalError("Exactly one input file should be provided.");
   }
 
-  std::string PreprocessedFile = InArgsInfo[0];
+  Opts.PrintCmdAndExit = InputArgs.hasArg(OPT__HASH_HASH_HASH);
-  if (!InputArgs.hasArg(OPT_no_preprocess)) {
+  Opts.Triple = getClangClTriple();
+  for (const auto *Arg :
+       InputArgs.filtered(OPT_includepath, OPT_define, OPT_undef)) {
+    switch (Arg->getOption().getID()) {
+    case OPT_includepath:
+      Opts.PreprocessArgs.push_back("-I");
+      break;
+    case OPT_define:
+      Opts.PreprocessArgs.push_back("-D");
+      break;
+    case OPT_undef:
+      Opts.PreprocessArgs.push_back("-U");
+      break;
+    }
+    Opts.PreprocessArgs.push_back(Arg->getValue());
+  }
+
+  Opts.InputFile = InArgsInfo[0];
+  Opts.BeVerbose = InputArgs.hasArg(OPT_verbose);
+  Opts.Preprocess = !InputArgs.hasArg(OPT_no_preprocess);
+  Opts.Params.Include = InputArgs.getAllArgValues(OPT_includepath);
+  Opts.Params.NoInclude = InputArgs.hasArg(OPT_noinclude);
+  if (Opts.Params.NoInclude) {
+    // Clear the INLCUDE variable for the external preprocessor
+#ifdef _WIN32
+    ::_putenv("INCLUDE=");
+#else
+    ::unsetenv("INCLUDE");
+#endif
+  }
+  if (InputArgs.hasArg(OPT_codepage)) {
+    if (InputArgs.getLastArgValue(OPT_codepage)
+            .getAsInteger(10, Opts.Params.CodePage))
+      fatalError("Invalid code page: " +
+                 InputArgs.getLastArgValue(OPT_codepage));
+  }
+  Opts.IsDryRun = InputArgs.hasArg(OPT_dry_run);
+  auto OutArgsInfo = InputArgs.getAllArgValues(OPT_fileout);
+  if (OutArgsInfo.empty()) {
+    SmallString<128> OutputFile(Opts.InputFile);
+    llvm::sys::fs::make_absolute(OutputFile);
+    llvm::sys::path::replace_extension(OutputFile, "res");
+    OutArgsInfo.push_back(std::string(OutputFile.str()));
+  }
+  if (!Opts.IsDryRun) {
+    if (OutArgsInfo.size() != 1)
+      fatalError(
+          "No more than one output file should be provided (using /FO flag).");
+    Opts.OutputFile = OutArgsInfo[0];
+  }
+  Opts.AppendNull = InputArgs.hasArg(OPT_add_null);
+  if (InputArgs.hasArg(OPT_lang_id)) {
+    if (InputArgs.getLastArgValue(OPT_lang_id).getAsInteger(16, Opts.LangId))
+      fatalError("Invalid language id: " +
+                 InputArgs.getLastArgValue(OPT_lang_id));
+  }
+  return Opts;
+}
+
+RcOptions getOptions(const char *Argv0, ArrayRef<const char *> ArgsArr,
+                     ArrayRef<const char *> InputArgs) {
+  std::string Prefix;
+  bool IsWindres;
+  std::tie(IsWindres, Prefix) = isWindres(Argv0);
+  if (IsWindres)
+    return parseWindresOptions(ArgsArr, InputArgs, Prefix);
+  else
+    return parseRcOptions(ArgsArr, InputArgs);
+}
+
+void doRc(std::string Src, std::string Dest, RcOptions &Opts,
+          const char *Argv0) {
+  std::string PreprocessedFile = Src;
+  if (Opts.Preprocess) {
     std::string OutFile = createTempFile("preproc", "rc");
     TempPreprocFile.setFile(OutFile);
-    if (preprocess(InArgsInfo[0], OutFile, InputArgs, Argv[0]))
+    if (preprocess(Src, OutFile, Opts, Argv0))
       PreprocessedFile = OutFile;
   }
 
@@ -240,7 +597,7 @@ int main(int Argc, const char **Argv) {
   ErrorOr<std::unique_ptr<MemoryBuffer>> File =
       MemoryBuffer::getFile(PreprocessedFile);
   if (!File) {
-    fatalError("Error opening file '" + Twine(InArgsInfo[0]) +
+    fatalError("Error opening file '" + Twine(PreprocessedFile) +
                "': " + File.getError().message());
   }
 
@@ -250,7 +607,7 @@ int main(int Argc, const char **Argv) {
   std::string FilteredContents = filterCppOutput(Contents);
   std::vector<RCToken> Tokens = ExitOnErr(tokenizeRC(FilteredContents));
 
-  if (BeVerbose) {
+  if (Opts.BeVerbose) {
     const Twine TokenNames[] = {
 #define TOKEN(Name) #Name,
 #define SHORT_TOKEN(Name, Ch) #Name,
@@ -267,80 +624,129 @@ int main(int Argc, const char **Argv) {
     }
   }
 
-  WriterParams Params;
+  WriterParams &Params = Opts.Params;
-  SmallString<128> InputFile(InArgsInfo[0]);
+  SmallString<128> InputFile(Src);
   llvm::sys::fs::make_absolute(InputFile);
   Params.InputFilePath = InputFile;
-  Params.Include = InputArgs.getAllArgValues(OPT_includepath);
-  Params.NoInclude = InputArgs.hasArg(OPT_noinclude);
 
-  if (InputArgs.hasArg(OPT_codepage)) {
+  switch (Params.CodePage) {
-    if (InputArgs.getLastArgValue(OPT_codepage)
+  case CpAcp:
-            .getAsInteger(10, Params.CodePage))
+  case CpWin1252:
-      fatalError("Invalid code page: " +
+  case CpUtf8:
-                 InputArgs.getLastArgValue(OPT_codepage));
+    break;
-    switch (Params.CodePage) {
+  default:
-    case CpAcp:
+    fatalError("Unsupported code page, only 0, 1252 and 65001 are supported!");
-    case CpWin1252:
-    case CpUtf8:
-      break;
-    default:
-      fatalError(
-          "Unsupported code page, only 0, 1252 and 65001 are supported!");
-    }
   }
 
   std::unique_ptr<ResourceFileWriter> Visitor;
-  bool IsDryRun = InputArgs.hasArg(OPT_dry_run);
-
-  if (!IsDryRun) {
-    auto OutArgsInfo = InputArgs.getAllArgValues(OPT_fileout);
-    if (OutArgsInfo.empty()) {
-      SmallString<128> OutputFile = InputFile;
-      llvm::sys::path::replace_extension(OutputFile, "res");
-      OutArgsInfo.push_back(std::string(OutputFile.str()));
-    }
-
-    if (OutArgsInfo.size() != 1)
-      fatalError(
-          "No more than one output file should be provided (using /FO flag).");
 
+  if (!Opts.IsDryRun) {
     std::error_code EC;
     auto FOut = std::make_unique<raw_fd_ostream>(
-        OutArgsInfo[0], EC, sys::fs::FA_Read | sys::fs::FA_Write);
+        Dest, EC, sys::fs::FA_Read | sys::fs::FA_Write);
     if (EC)
-      fatalError("Error opening output file '" + OutArgsInfo[0] +
+      fatalError("Error opening output file '" + Dest + "': " + EC.message());
-                 "': " + EC.message());
     Visitor = std::make_unique<ResourceFileWriter>(Params, std::move(FOut));
-    Visitor->AppendNull = InputArgs.hasArg(OPT_add_null);
+    Visitor->AppendNull = Opts.AppendNull;
 
     ExitOnErr(NullResource().visit(Visitor.get()));
 
-    // Set the default language; choose en-US arbitrarily.
+    unsigned PrimaryLangId = Opts.LangId & 0x3ff;
-    unsigned PrimaryLangId = 0x09, SubLangId = 0x01;
+    unsigned SubLangId = Opts.LangId >> 10;
-    if (InputArgs.hasArg(OPT_lang_id)) {
-      unsigned LangId;
-      if (InputArgs.getLastArgValue(OPT_lang_id).getAsInteger(16, LangId))
-        fatalError("Invalid language id: " +
-                   InputArgs.getLastArgValue(OPT_lang_id));
-      PrimaryLangId = LangId & 0x3ff;
-      SubLangId = LangId >> 10;
-    }
     ExitOnErr(LanguageResource(PrimaryLangId, SubLangId).visit(Visitor.get()));
   }
 
   rc::RCParser Parser{std::move(Tokens)};
   while (!Parser.isEof()) {
     auto Resource = ExitOnErr(Parser.parseSingleResource());
-    if (BeVerbose)
+    if (Opts.BeVerbose)
       Resource->log(outs());
-    if (!IsDryRun)
+    if (!Opts.IsDryRun)
       ExitOnErr(Resource->visit(Visitor.get()));
   }
 
   // STRINGTABLE resources come at the very end.
-  if (!IsDryRun)
+  if (!Opts.IsDryRun)
     ExitOnErr(Visitor->dumpAllStringTables());
+}
+
+void doCvtres(std::string Src, std::string Dest, std::string TargetTriple) {
+  object::WindowsResourceParser Parser;
+
+  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+      MemoryBuffer::getFile(Src);
+  if (!BufferOrErr)
+    fatalError("Error opening file '" + Twine(Src) +
+               "': " + BufferOrErr.getError().message());
+  std::unique_ptr<MemoryBuffer> &Buffer = BufferOrErr.get();
+  std::unique_ptr<object::WindowsResource> Binary =
+      ExitOnErr(object::WindowsResource::createWindowsResource(
+          Buffer->getMemBufferRef()));
+
+  std::vector<std::string> Duplicates;
+  ExitOnErr(Parser.parse(Binary.get(), Duplicates));
+  for (const auto &DupeDiag : Duplicates)
+    fatalError("Duplicate resources: " + DupeDiag);
+
+  Triple T(TargetTriple);
+  COFF::MachineTypes MachineType;
+  switch (T.getArch()) {
+  case Triple::x86:
+    MachineType = COFF::IMAGE_FILE_MACHINE_I386;
+    break;
+  case Triple::x86_64:
+    MachineType = COFF::IMAGE_FILE_MACHINE_AMD64;
+    break;
+  case Triple::arm:
+  case Triple::thumb:
+    MachineType = COFF::IMAGE_FILE_MACHINE_ARMNT;
+    break;
+  case Triple::aarch64:
+    MachineType = COFF::IMAGE_FILE_MACHINE_ARM64;
+    break;
+  default:
+    fatalError("Unsupported architecture in target '" + Twine(TargetTriple) +
+               "'");
+  }
+
+  std::unique_ptr<MemoryBuffer> OutputBuffer =
+      ExitOnErr(object::writeWindowsResourceCOFF(MachineType, Parser,
+                                                 /*DateTimeStamp*/ 0));
+  std::unique_ptr<FileOutputBuffer> FileBuffer =
+      ExitOnErr(FileOutputBuffer::create(Dest, OutputBuffer->getBufferSize()));
+  std::copy(OutputBuffer->getBufferStart(), OutputBuffer->getBufferEnd(),
+            FileBuffer->getBufferStart());
+  ExitOnErr(FileBuffer->commit());
+}
+
+} // anonymous namespace
+
+int main(int Argc, const char **Argv) {
+  InitLLVM X(Argc, Argv);
+  ExitOnErr.setBanner("llvm-rc: ");
+
+  const char **DashDash = std::find_if(
+      Argv + 1, Argv + Argc, [](StringRef Str) { return Str == "--"; });
+  ArrayRef<const char *> ArgsArr = makeArrayRef(Argv + 1, DashDash);
+  ArrayRef<const char *> FileArgsArr;
+  if (DashDash != Argv + Argc)
+    FileArgsArr = makeArrayRef(DashDash + 1, Argv + Argc);
+
+  RcOptions Opts = getOptions(Argv[0], ArgsArr, FileArgsArr);
+
+  std::string ResFile = Opts.OutputFile;
+  if (Opts.InputFormat == Rc) {
+    if (Opts.OutputFormat == Coff) {
+      ResFile = createTempFile("rc", "res");
+      TempResFile.setFile(ResFile);
+    }
+    doRc(Opts.InputFile, ResFile, Opts, Argv[0]);
+  } else {
+    ResFile = Opts.InputFile;
+  }
+  if (Opts.OutputFormat == Coff) {
+    doCvtres(ResFile, Opts.OutputFile, Opts.Triple);
+  }
 
   return 0;
 }