fix: ipsw dsc disass --demangle support + minor fixes

Author: blacktop

cmd/ipsw/cmd/dyld/dyld_disass.go

@@ -179,7 +179,7 @@ var DisassCmd = &cobra.Command{
 			return nil
 		}
 
-		if !quiet && len(symbolName) > 0 {
+		if !quiet || len(symbolName) > 0 {
 			if len(cacheFile) == 0 {
 				cacheFile = dscPath + ".a2s"
 			}

pkg/disass/disass.go

@@ -268,8 +268,10 @@ func Disassemble(d Disass) string {
 					}
 				}
 
-				if swiftstr, ok := d.FindSwiftString(instruction.Address); ok {
-					comment = fmt.Sprintf(" ; %#v", swiftstr)
+				if instruction.Address != startAddr {
+					if swiftstr, ok := d.FindSwiftString(instruction.Address); ok {
+						comment = fmt.Sprintf(" ; %#v", swiftstr)
+					}
 				}
 
 				// if ok, imm := triage.HasLoc(i.Instruction.Address()); ok {

pkg/dyld/image.go

@@ -532,6 +532,11 @@ func (i *CacheImage) GetPartialMacho() (*macho.File, error) {
 // Analyze analyzes an image by parsing it's symbols, stubs and GOT
 func (i *CacheImage) Analyze() error {
 
+	if err := i.ParseObjC(); err != nil {
+		log.Errorf("failed to parse objc data for image %s: %v", filepath.Base(i.Name), err)
+		// return fmt.Errorf("failed to parse objc data for image %s: %v", filepath.Base(i.Name), err) FIXME: should this error out?
+	}
+
 	if err := i.ParsePublicSymbols(false); err != nil {
 		log.Errorf("failed to parse exported symbols for %s: %w", i.Name, err)
 	}
@@ -542,11 +547,6 @@ func (i *CacheImage) Analyze() error {
 		}
 	}
 
-	if err := i.ParseObjC(); err != nil {
-		log.Errorf("failed to parse objc data for image %s: %v", filepath.Base(i.Name), err)
-		// return fmt.Errorf("failed to parse objc data for image %s: %v", filepath.Base(i.Name), err) FIXME: should this error out?
-	}
-
 	if !i.cache.IsArm64() {
 		utils.Indent(log.Warn, 2)("image analysis of stubs and GOT only works on arm64 architectures")
 	}

pkg/dyld/symbols.go

@@ -382,11 +382,7 @@ func (f *File) OpenOrCreateA2SCache(cacheFile string) error {
 				}
 				for stub, target := range f.islandStubs {
 					if symName, ok := f.AddressToSymbol[target]; ok {
-						if !strings.HasPrefix(symName, "j_") {
-							f.AddressToSymbol[stub] = "j_" + strings.TrimPrefix(symName, "__stub_helper.")
-						} else {
-							f.AddressToSymbol[stub] = symName
-						}
+						f.AddressToSymbol[stub] = symName
 					}
 				}
 			}