com.facebook.buck.cxx.toolchain.objectfile

Class Machos

java.lang.Object

com.facebook.buck.cxx.toolchain.objectfile.Machos

public class Machos
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Machos.MachoException

Field Summary

Fields

Modifier and Type	Field and Description
static int	LC_DYLD_INFO_ONLY
static int	LC_SYMTAB

Method Summary

Modifier and Type	Method and Description
static Map<byte[],byte[]>	generateReplacementMap(Map<Path,Path> pathMap) Prepares a replacement map for prefixes.
protected static com.facebook.buck.cxx.toolchain.objectfile.MachoHeader	getHeader(MappedByteBuffer map) Returns the Mach-O header provided the file is Mach-O, otherwise throws an exception.
static Optional<ByteBuffer>	tryRewritingMatchingPath(byte[] stringBytes, int stringOffset, Map<byte[],byte[]> replacementMap) Checks whether a string matches a prefix and returns a rewritten copy if that's the case.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LC_SYMTAB

public static final int LC_SYMTAB

See Also:

Constant Field Values

LC_DYLD_INFO_ONLY

public static final int LC_DYLD_INFO_ONLY

See Also:

Constant Field Values

Method Detail

getHeader

protected static com.facebook.buck.cxx.toolchain.objectfile.MachoHeader getHeader(MappedByteBuffer map)
                                                                           throws Machos.MachoException

Returns the Mach-O header provided the file is Mach-O, otherwise throws an exception.

Throws:

Machos.MachoException

generateReplacementMap

public static Map<byte[],byte[]> generateReplacementMap(Map<Path,Path> pathMap)

Prepares a replacement map for prefixes. For example, if had two entries: 1. "/path/to/repo" -> "", 2. "/path/to/repo/cell" -> "cell"

The resulting map would contain: 1. "/path/to/repo/" -> "./" 2. "/path/to/repo/cell/" -> "cell/"

The above means we can do very simple (and fast!) search & replace.

tryRewritingMatchingPath

public static Optional<ByteBuffer> tryRewritingMatchingPath(byte[] stringBytes,
                                                            int stringOffset,
                                                            Map<byte[],byte[]> replacementMap)

Checks whether a string matches a prefix and returns a rewritten copy if that's the case. For example, given a string "/Users/fb/repo/cell" and a replacement map containing "/Users/fb/repo/" -> "./", it will return a ByteBuffer wrapping "./cell".

NB: This is a perf sensitive method.