[llvm-rc] Accept filenames provided as multiple string literals

llvm/test/tools/llvm-rc/Inputs/split-path.rc

@@ -0,0 +1,2 @@
+100 ICON "subdir" "/icon-new.ico"
+101 24 "subdir" "/empty.manifest"

llvm/test/tools/llvm-rc/split-path.test

@@ -0,0 +1,7 @@
+; RUN: rm -rf %t
+; RUN: mkdir %t
+; RUN: cd %t
+; RUN: mkdir subdir
+; RUN: cp %p/Inputs/icon-new.ico subdir
+; RUN: touch subdir/empty.manifest
+; RUN: llvm-windres --no-preprocess %p/Inputs/split-path.rc %t/split-path.res

llvm/tools/llvm-rc/ResourceScriptParser.cpp

@@ -238,7 +238,24 @@ Expected<StringRef> RCParser::readString() {
 Expected<StringRef> RCParser::readFilename() {
   if (!isNextTokenKind(Kind::String) && !isNextTokenKind(Kind::Identifier))
     return getExpectedError("string");
-  return read().value();
+  const RCToken &Token = read();
+  StringRef Str = Token.value();
+  if (Token.kind() != Kind::String)
+    return Str;
+  while (isNextTokenKind(Kind::String)) {
+    const RCToken &NextToken = read();
+    StringRef Next = NextToken.value();
+    bool IsWide = Str.consume_front_insensitive("L");
+    Next.consume_front_insensitive("L");
+    bool StrUnquoted = Str.consume_front("\"") && Str.consume_back("\"");
+    bool NextUnquoted = Next.consume_front("\"") && Next.consume_back("\"");
+    assert(StrUnquoted && NextUnquoted);
+    (void)StrUnquoted;
+    (void)NextUnquoted;
+
+    Str = Saver.save(Twine(IsWide ? "L" : "") + "\"" + Str + Next + "\"");
+  }
+  return Str;
 }
 
 Expected<StringRef> RCParser::readIdentifier() {
@@ -499,9 +516,10 @@ RCParser::ParseType RCParser::parseUserDefinedResource(IntOrString Type) {
   // Check if this is a file resource.
   switch (look().kind()) {
   case Kind::String:
-  case Kind::Identifier:
-    return std::make_unique<UserDefinedResource>(Type, read().value(),
-                                                 MemoryFlags);
+  case Kind::Identifier: {
+    ASSIGN_OR_RETURN(Filename, readFilename());
+    return std::make_unique<UserDefinedResource>(Type, *Filename, MemoryFlags);
+  }
   default:
     break;
   }

llvm/tools/llvm-rc/ResourceScriptParser.h

@@ -18,6 +18,7 @@
 #include "ResourceScriptToken.h"
 
 #include "llvm/Support/Compiler.h"
+#include "llvm/Support/StringSaver.h"
 #include "llvm/Support/raw_ostream.h"
 
 #include <system_error>
@@ -185,6 +186,9 @@ class RCParser {
   std::vector<RCToken> Tokens;
   LocIter CurLoc;
   const LocIter End;
+
+  BumpPtrAllocator Alloc;
+  StringSaver Saver{Alloc};
 };
 
 } // namespace rc