Can't pass .dSYM directory to llvm-objdump -dsym= (and error message is wrong)

[mtrent]

Summary

Allow users to pass the path to a .dSYM directory to llvm-objdump's -dsym
flag rather than requiring users to find the DWARF DSYM Mach-O within the
bundle structure by hand.

rdar://46873333

[pete]

LGTM

[MaskRay]

tools/llvm-objdump/MachODump.cpp

7345

if -> If

7354

load -> Load. And append a full stop.

[aprantl]

tools/llvm-objdump/MachODump.cpp

7350

sys::path::append() is slightly more portable over hardcoding the path separators. Not sure if anyone would ever want to run this on Windows...

[mtrent]

Updating to use path::append to build the bundle contents string.

[mtrent]

mechanical comment changes

tools/llvm-objdump/MachODump.cpp

#endif
   std::unique_ptr<Binary> DSYMBinary;
   std::unique_ptr<MemoryBuffer> DSYMBuf;
   if (UseDbg) {
     ObjectFile *DbgObj = MachOOF;
 
     // A separate DSym file path was specified, parse it as a macho file,
     // get the sections and supply it to the section name parsing machinery.
     if (!DSYMFile.empty()) {
+      std::string DSYMPath(DSYMFile);
+
+      // if DSYMPath is a .dSYM directory, append the Mach-O file.
+      if (llvm::sys::fs::is_directory(DSYMPath) &&
+          llvm::sys::path::extension(DSYMPath) == ".dSYM") {
+        SmallString<128> ShortName(llvm::sys::path::filename(DSYMPath));
+        llvm::sys::path::replace_extension(ShortName, "");
+        Twine Path(DSYMPath + "/Contents/Resources/DWARF/" + ShortName);
+        DSYMPath = Path.str();
+      }
+
+      // load the file
       ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
-          MemoryBuffer::getFileOrSTDIN(DSYMFile);
+          MemoryBuffer::getFileOrSTDIN(DSYMPath);
       if (std::error_code EC = BufOrErr.getError()) {
-        reportError(errorCodeToError(EC), DSYMFile);
+        reportError(errorCodeToError(EC), DSYMPath);
         return;
       }
 
       // We need to keep the file alive, because we're replacing DbgObj with it.
       DSYMBuf = std::move(BufOrErr.get());
 
       Expected<std::unique_ptr<Binary>> BinaryOrErr =
       createBinary(DSYMBuf.get()->getMemBufferRef());
       if (!BinaryOrErr) {
-        reportError(BinaryOrErr.takeError(), DSYMFile);
+        reportError(BinaryOrErr.takeError(), DSYMPath);
         return;
       }
 
-      // We need to keep the Binary elive with the buffer
+      // We need to keep the Binary alive with the buffer
       DSYMBinary = std::move(BinaryOrErr.get());
-    
       if (ObjectFile *O = dyn_cast<ObjectFile>(DSYMBinary.get())) {
         // this is a Mach-O object file, use it
         if (MachOObjectFile *MachDSYM = dyn_cast<MachOObjectFile>(&*O)) {
           DbgObj = MachDSYM;
         }
         else {
           WithColor::error(errs(), "llvm-objdump")
-            << DSYMFile << " is not a Mach-O file type.\n";
+            << DSYMPath << " is not a Mach-O file type.\n";
           return;
         }
       }
       else if (auto UB = dyn_cast<MachOUniversalBinary>(DSYMBinary.get())){
         // this is a Universal Binary, find a Mach-O for this architecture
         uint32_t CPUType, CPUSubType;
         const char *ArchFlag;
         if (MachOOF->is64Bit()) {
           const MachO::mach_header_64 H_64 = MachOOF->getHeader64();
           CPUType = H_64.cputype;
           CPUSubType = H_64.cpusubtype;
         } else {
           const MachO::mach_header H = MachOOF->getHeader();
           CPUType = H.cputype;
           CPUSubType = H.cpusubtype;
         }
         Triple T = MachOObjectFile::getArchTriple(CPUType, CPUSubType, nullptr,
                                                   &ArchFlag);
         Expected<std::unique_ptr<MachOObjectFile>> MachDSYM =
             UB->getMachOObjectForArch(ArchFlag);
         if (!MachDSYM) {
-          reportError(MachDSYM.takeError(), DSYMFile);
+          reportError(MachDSYM.takeError(), DSYMPath);
           return;
         }
     
-        // We need to keep the Binary elive with the buffer
+        // We need to keep the Binary alive with the buffer
         DbgObj = &*MachDSYM.get();
         DSYMBinary = std::move(*MachDSYM);
       }
       else {
         WithColor::error(errs(), "llvm-objdump")
-          << DSYMFile << " is not a Mach-O or Universal file type.\n";
+          << DSYMPath << " is not a Mach-O or Universal file type.\n";
         return;
       }
     }
 
     // Setup the DIContext
     diContext = DWARFContext::create(*DbgObj);
   }