[COFF] Don't try to add quotes to already quoted linker directives

[mkuper]

Summary

If a linker directive is already quoted, don't try to quote it again, otherwise it creates a mess.

This pops up in places like:
#pragma comment(linker,"\"/foo bar'\"")

[majnemer]

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

989 ↗

(On Diff #17666)

This would probably be a little nicer as:
if (!Op.startswith("\"") && Op.find(" ") != StringRef::npos)

This way we don't need to hunt for spaces if it starts with a \" sequence.

[mkuper]

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

989 ↗

(On Diff #17666)

Right, noticed that myself after uploading, thanks. :-)

[rnk]

lgtm with David's suggestion

llvm/trunk/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

emitModuleFlags(MCStreamer &Streamer,
   Streamer.SwitchSection(Sec);
   for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
     MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
     for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
       MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
       StringRef Op = MDOption->getString();
       // Lead with a space for consistency with our dllexport implementation.
       std::string Escaped(" ");
-      if (Op.find(" ") != StringRef::npos) {
+      if (!Op.startswith("\"") && (Op.find(" ") != StringRef::npos)) {
         // The PE-COFF spec says args with spaces must be quoted.  It doesn't say
         // how to escape quotes, but it probably uses this algorithm:
         // http://msdn.microsoft.com/en-us/library/17w5ykft(v=vs.85).aspx
         // FIXME: Reuse escaping code from Support/Windows/Program.inc
         Escaped.push_back('\"');
         Escaped.append(Op);
         Escaped.push_back('\"');
       } else {

llvm/trunk/test/MC/COFF/linker-options.ll

 ; RUN: llc -O0 -mtriple=i386-pc-win32 -filetype=asm -o - %s | FileCheck %s
 
-!0 = !{i32 6, !"Linker Options", !{!{!"/DEFAULTLIB:msvcrt.lib"}, !{!"/DEFAULTLIB:msvcrt.lib", !"/DEFAULTLIB:secur32.lib"}, !{!"/DEFAULTLIB:C:\5Cpath to\5Casan_rt.lib"}, !{!"/with spaces"}}}
+!0 = !{i32 6, !"Linker Options", !{!{!"/DEFAULTLIB:msvcrt.lib"}, !{!"/DEFAULTLIB:msvcrt.lib", !"/DEFAULTLIB:secur32.lib"}, !{!"/DEFAULTLIB:C:\5Cpath to\5Casan_rt.lib"}, !{!"/with spaces"}, !{!"\22/quoted spaces\22"}}}
 
 !llvm.module.flags = !{ !0 }
 
 define dllexport void @foo() {
   ret void
 }
 
 ; CHECK: .section        .drectve,"yn"
 ; CHECK: .ascii   " /DEFAULTLIB:msvcrt.lib"
 ; CHECK: .ascii   " /DEFAULTLIB:msvcrt.lib"
 ; CHECK: .ascii   " /DEFAULTLIB:secur32.lib"
 ; CHECK: .ascii   " \"/DEFAULTLIB:C:\\path to\\asan_rt.lib\""
 ; CHECK: .ascii   " \"/with spaces\""
+; CHECK: .ascii   " \"/quoted spaces\""
 ; CHECK: .ascii   " /EXPORT:_foo"