[PDB] Quote linker arguments containing spaces (mimic MSVC)

[aganea]

Summary

Expand cmd-line in * Linker * module by double-quoting arguments with spaces when needed.
Double double-quotes are correctly escaped as suggested by @ruiu.

Tested on Windows and WSL Ubuntu. The cmd-line in the S_ENVBLOCK can now be extracted and executed as-it on Windows; however on Linux that would require some extra parsing as single/double-quotes are treated differently.

This is a replacement for D46427. After discussing with @lantictac offline, we agreed that I will finish his patch.

============================================================
  Mod 0001 | `* Linker *`:
...      64 | S_ENVBLOCK [size = 404]
           - cwd
           - /mnt/f/svn/buildWSL/tools/lld/test/COFF
           - exe
           - /mnt/f/svn/buildWSL/bin/lld-link
           - pdb
           - /mnt/f/svn/buildWSL/tools/lld/test/COFF/Output/pdb-linker-module.test.tmp.pdb
           - cmd
           - /debug /pdb:/mnt/f/svn/buildWSL/tools/lld/test/COFF/Output/pdb-linker-module.test.tmp.pdb /nodefaultlib "/entry:1 ""hello"" 2" "/manifestuac:level='asInvoker' uiAccess='false'" /mnt/f/svn/lld/test/COFF/Inputs/pdb-diff.obj /force

[ruiu]

Looks good, but I just want to make sure that you have already run the exact same test with MSVC to get the same result.

[aganea]

Yes I did - I've also tried piggybacking the result from the PDB on the command-line and it generates the same PDB.

aganea@PC MINGW64 /f/svn/lld
$ py /f/svn/build/bin/llvm-lit.py -vv test/COFF/pdb-linker-module.test
-- Testing: 1 tests, 1 threads --
PASS: lld :: COFF/pdb-linker-module.test (1 of 1)
Testing Time: 0.33s
  Expected Passes    : 1

$ "F:\svn\build\bin\llvm-pdbutil.EXE" "dump" -modi=1 -symbols "F:\svn\build\tools\lld\test\COFF\Output\pdb-linker-module.test.tmp.pdb"

                          Symbols
============================================================
  Mod 0001 | `* Linker *`:
       4 | S_OBJNAME [size = 20] sig=0, `* Linker *`
      24 | S_COMPILE3 [size = 40]
           machine = intel 80386, Ver = LLVM Linker, language = link
           frontend = 0.0.0.0, backend = 14.10.25019.0
           flags = none
      64 | S_ENVBLOCK [size = 376]
           - cwd
           - F:\svn\build\tools\lld\test\COFF
           - exe
           - F:\svn\build\bin\lld-link.exe
           - pdb
           - F:\svn\build\tools\lld\test\COFF\Output\pdb-linker-module.test.tmp.pdb
           - cmd
           - /debug /pdb:F:\svn\build\tools\lld\test\COFF\Output\pdb-linker-module.test.tmp.pdb /nodefaultlib "/entry:1 ""hello"" 2" "/manifestuac:level='asInvoker' uiAccess='false'" F:\svn\lld\test\COFF/Inputs/pdb-diff.obj /force
     440 | S_SECTION [size = 28] `.text`
           length = 10, alignment = 12, rva = 4096, section # = 1
           characteristics =
             code
             execute permissions
             read permissions
     468 | S_SECTION [size = 28] `.rdata`
           length = 123, alignment = 12, rva = 8192, section # = 2
           characteristics =
             initialized data
             read permissions
     496 | S_SECTION [size = 28] `.data`
           length = 4, alignment = 12, rva = 12288, section # = 3
           characteristics =
             initialized data
             read permissions
             write permissions

[ruiu]

LGTM

COFF/PDB.cpp

case COFF::IMAGE_FILE_MACHINE_ARMNT:
     return codeview::CPUType::ARMNT;
   case COFF::IMAGE_FILE_MACHINE_I386:
     return codeview::CPUType::Intel80386;
   default:
     llvm_unreachable("Unsupported CPU Type");
   }
 }
 
+// Mimic MSVC which surrounds arguments containing whitespace with quotes.
+// Double double-quotes are handled, so that the resulting string can be
+// executed again on the cmd-line.
+static std::string quote(ArrayRef<StringRef> Args) {
+  std::string R;
+  R.reserve(256);
+  for (StringRef A : Args) {
+    if (!R.empty())
+      R.push_back(' ');
+    bool HasWS = A.find(' ') != StringRef::npos;
+    bool HasQ = A.find('"') != StringRef::npos;
+    if (HasWS || HasQ)
+      R.push_back('"');
+    if (HasQ) {
+      SmallVector<StringRef, 4> S;
+      A.split(S, '"');
+      R.append(join(S, "\"\""));
+    } else {
+      R.append(A);
+    }
+    if (HasWS || HasQ)
+      R.push_back('"');
+  }
+  return R;
+}
+
 static void addCommonLinkerModuleSymbols(StringRef Path,
                                          pdb::DbiModuleDescriptorBuilder &Mod,
                                          BumpPtrAllocator &Allocator) {
   ObjNameSym ONS(SymbolRecordKind::ObjNameSym);
   Compile3Sym CS(SymbolRecordKind::Compile3Sym);
   EnvBlockSym EBS(SymbolRecordKind::EnvBlockSym);
 
   ONS.Name = "* Linker *";
static void addCommonLinkerModuleSymbols(StringRef Path,
   CS.VersionFrontendBuild = 0;
   CS.VersionFrontendMajor = 0;
   CS.VersionFrontendMinor = 0;
   CS.VersionFrontendQFE = 0;
   CS.Version = "LLVM Linker";
   CS.setLanguage(SourceLanguage::Link);
 
   ArrayRef<StringRef> Args = makeArrayRef(Config->Argv).drop_front();
-  std::string ArgStr = llvm::join(Args, " ");
+  std::string ArgStr = quote(Args);
   EBS.Fields.push_back("cwd");
   SmallString<64> cwd;
   if (Config->PDBSourcePath.empty()) 
     sys::fs::current_path(cwd);
   else
     cwd = Config->PDBSourcePath;
   EBS.Fields.push_back(cwd);
   EBS.Fields.push_back("exe");

test/COFF/pdb-linker-module.test

 RUN: echo "/nodefaultlib" > %t.rsp
-RUN: lld-link /debug /pdb:%t.pdb @%t.rsp /entry:main %S/Inputs/pdb-diff.obj
+RUN: lld-link /debug /pdb:%t.pdb @%t.rsp /entry:"1 "'"'hello'"'" 2" /manifestuac:"level='asInvoker' uiAccess='false'" %S/Inputs/pdb-diff.obj /force
 RUN: llvm-pdbutil dump -modules %t.pdb | FileCheck --check-prefix=MODS %s
 RUN: llvm-pdbutil dump -symbols %t.pdb | FileCheck --check-prefix=SYMS %s
 
 MODS:      Mod 0001 | `* Linker *`
 MODS-NEXT:             Obj: ``:
 MODS-NEXT:             debug stream: 13, # files: 0, has ec info: false
 MODS-NEXT:             pdb file ni: 1 `{{.*}}pdb-linker-module.test.tmp.pdb`, src file ni: 0 ``
 
 SYMS:      Mod 0001 | `* Linker *`
 SYMS-NEXT:  4 | S_OBJNAME [size = 20] sig=0, `* Linker *`
 SYMS-NEXT: 24 | S_COMPILE3 [size = 40]
 SYMS-NEXT:      machine = intel 80386, Ver = LLVM Linker, language = link
 SYMS-NEXT:      frontend = 0.0.0.0, backend = 14.10.25019.0
 SYMS-NEXT:      flags = none
 SYMS-NEXT: 64 | S_ENVBLOCK
 SYMS-NEXT: - cwd
 SYMS-NEXT: -
 SYMS-NEXT: - exe
 SYMS-NEXT: - {{.*}}lld-link
 SYMS-NEXT: - pdb
 SYMS-NEXT: - {{.*}}pdb-linker-module{{.*}}pdb
 SYMS-NEXT: - cmd
-SYMS-NEXT: - /debug /pdb:{{.*}}pdb-linker-module{{.*}}pdb /nodefaultlib /entry:main {{.*}}pdb-diff.obj
+SYMS-NEXT: - /debug /pdb:{{.*}}pdb-linker-module{{.*}}pdb /nodefaultlib "/entry:1 ""hello"" 2" "/manifestuac:level='asInvoker' uiAccess='false'" {{.*}}pdb-diff.obj