fat_file: Add delegation to header/canonical Mach-O where possible.

The "canonical" Mach-O for a fat file is just the first Mach-O,
used to obtain attributes that should be constant across all
slices.

macho_file: Add delegation to header, fix YARD errors.

load_commands: Fix typo.

Author: woodruffw

lib/macho/fat_file.rb

@@ -1,9 +1,13 @@
+require "forwardable"
+
 module MachO
   # Represents a "Fat" file, which contains a header, a listing of available
   # architectures, and one or more Mach-O binaries.
   # @see https://en.wikipedia.org/wiki/Mach-O#Multi-architecture_binaries
   # @see MachO::MachOFile
   class FatFile
+    extend Forwardable
+
     # @return [String] the filename loaded from, or nil if loaded from a binary string
     attr_accessor :filename
 
@@ -74,72 +78,43 @@ def serialize
       @raw_data
     end
 
-    # @return [Boolean] true if the file is of type `MH_OBJECT`, false otherwise
-    def object?
-      machos.first.object?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_EXECUTE`, false otherwise
-    def executable?
-      machos.first.executable?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_FVMLIB`, false otherwise
-    def fvmlib?
-      machos.first.fvmlib?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_CORE`, false otherwise
-    def core?
-      machos.first.core?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_PRELOAD`, false otherwise
-    def preload?
-      machos.first.preload?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_DYLIB`, false otherwise
-    def dylib?
-      machos.first.dylib?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_DYLINKER`, false otherwise
-    def dylinker?
-      machos.first.dylinker?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_BUNDLE`, false otherwise
-    def bundle?
-      machos.first.bundle?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_DSYM`, false otherwise
-    def dsym?
-      machos.first.dsym?
-    end
-
-    # @return [Boolean] true if the file is of type `MH_KEXT_BUNDLE`, false otherwise
-    def kext?
-      machos.first.kext?
-    end
-
-    # @return [Fixnum] the file's magic number
-    def magic
-      header.magic
-    end
+    # @!method object?
+    #  @return (see MachO::MachOFile#object?)
+    # @!method executable?
+    #  @return (see MachO::MachOFile#executable?)
+    # @!method fvmlib?
+    #  @return (see MachO::MachOFile#fvmlib?)
+    # @!method core?
+    #  @return (see MachO::MachOFile#core?)
+    # @!method preload?
+    #  @return (see MachO::MachOFile#preload?)
+    # @!method dylib?
+    #  @return (see MachO::MachOFile#dylib?)
+    # @!method dylinker?
+    #  @return (see MachO::MachOFile#dylinker?)
+    # @!method bundle?
+    #  @return (see MachO::MachOFile#bundle?)
+    # @!method dsym?
+    #  @return (see MachO::MachOFile#dsym?)
+    # @!method kext?
+    #  @return (see MachO::MachOFile#kext?)
+    # @!method filetype
+    #  @return (see MachO::MachOFile#filetype)
+    # @!method dylib_id
+    #  @return (see MachO::MachOFile#dylib_id)
+    def_delegators :canonical_macho, :object?, :executable?, :fvmlib?,
+                   :core?, :preload?, :dylib?, :dylinker?, :bundle?,
+                   :dsym?, :kext?, :filetype, :dylib_id
+
+    # @!method magic
+    #  @return (see MachO::Headers::FatHeader#magic)
+    def_delegators :header, :magic
 
     # @return [String] a string representation of the file's magic number
     def magic_string
       Headers::MH_MAGICS[magic]
     end
 
-    # The file's type. Assumed to be the same for every Mach-O within.
-    # @return [Symbol] the filetype
-    def filetype
-      machos.first.filetype
-    end
-
     # Populate the instance's fields with the raw Fat Mach-O data.
     # @return [void]
     # @note This method is public, but should (almost) never need to be called.
@@ -155,15 +130,6 @@ def dylib_load_commands
       machos.map(&:dylib_load_commands).flatten
     end
 
-    # The file's dylib ID. If the file is not a dylib, returns `nil`.
-    # @example
-    #  file.dylib_id # => 'libBar.dylib'
-    # @return [String, nil] the file's dylib ID
-    # @see MachO::MachOFile#linked_dylibs
-    def dylib_id
-      machos.first.dylib_id
-    end
-
     # Changes the file's dylib ID to `new_id`. If the file is not a dylib, does nothing.
     # @example
     #  file.change_dylib_id('libFoo.dylib')
@@ -395,5 +361,13 @@ def each_macho(options = {})
       # Non-strict mode: Raise first error if *all* Mach-O slices failed.
       raise errors.first if errors.size == machos.size
     end
+
+    # Return a single-arch Mach-O that represents this fat Mach-O for purposes
+    #  of delegation.
+    # @return [MachO::MachOFile] the Mach-O file
+    # @api private
+    def canonical_macho
+      machos.first
+    end
   end
 end

lib/macho/load_commands.rb

@@ -2,7 +2,7 @@ module MachO
   # Classes and constants for parsing load commands in Mach-O binaries.
   module LoadCommands
     # load commands added after OS X 10.1 need to be bitwise ORed with
-    # LC_REQ_DYLD to be recognized by the dynamic linder (dyld)
+    # LC_REQ_DYLD to be recognized by the dynamic linker (dyld)
     # @api private
     LC_REQ_DYLD = 0x80000000
 

lib/macho/macho_file.rb

@@ -1,10 +1,14 @@
+require "forwardable"
+
 module MachO
   # Represents a Mach-O file, which contains a header and load commands
   # as well as binary executable instructions. Mach-O binaries are
   # architecture specific.
   # @see https://en.wikipedia.org/wiki/Mach-O
   # @see MachO::FatFile
   class MachOFile
+    extend Forwardable
+
     # @return [String] the filename loaded from, or nil if loaded from a binary string
     attr_accessor :filename
 
@@ -120,11 +124,6 @@ def kext?
       header.filetype == Headers::MH_KEXT_BUNDLE
     end
 
-    # @return [Fixnum] the file's magic number
-    def magic
-      header.magic
-    end
-
     # @return [String] a string representation of the file's magic number
     def magic_string
       Headers::MH_MAGICS[magic]
@@ -145,20 +144,15 @@ def cpusubtype
       Headers::CPU_SUBTYPES[header.cputype][header.cpusubtype]
     end
 
-    # @return [Fixnum] the number of load commands in the Mach-O's header
-    def ncmds
-      header.ncmds
-    end
-
-    # @return [Fixnum] the size of all load commands, in bytes
-    def sizeofcmds
-      header.sizeofcmds
-    end
-
-    # @return [Fixnum] execution flags set by the linker
-    def flags
-      header.flags
-    end
+    # @!method magic
+    #  @return (see MachO::Headers::MachHeader#magic)
+    # @!method ncmds
+    #  @return (see MachO::Headers::MachHeader#ncmds)
+    # @!method sizeofcmds
+    #  @return (see MachO::Headers::MachHeader#sizeofcmds)
+    # @!method flags
+    #  @return (see MachO::Headers::MachHeader#flags)
+    def_delegators :header, :magic, :ncmds, :sizeofcmds, :flags
 
     # All load commands of a given name.
     # @example
@@ -211,7 +205,7 @@ def insert_command(offset, lc, options = {})
     # @param new_lc [MachO::LoadCommands::LoadCommand] the load command being added
     # @return [void]
     # @raise [MachO::HeaderPadError] if the new command exceeds the header pad buffer
-    # @see {#insert_command}
+    # @see #insert_command
     # @note This is public, but methods like {#dylib_id=} should be preferred.
     def replace_command(old_lc, new_lc)
       context = LoadCommands::LoadCommand::SerializationContext.context_for(self)
@@ -231,7 +225,7 @@ def replace_command(old_lc, new_lc)
     # @option options [Boolean] :repopulate (true) whether or not to repopulate
     #  the instance fields
     # @return [void]
-    # @see {#insert_command}
+    # @see #insert_command
     # @note This is public, but methods like {#add_rpath} should be preferred.
     #  Setting `repopulate` to false **will leave the instance in an
     #  inconsistent state** unless {#populate_fields} is called **immediately**