def objectDir = tmpDirProvider.createDir("pch")
        def prefixFile = tempDir.createFile("header.h")
        def objectFile = tempDir.createFile("header.o")
        prefixFile << "#include <stdio.h>"
        objectFile << "some content"

        when:
        def generated = PCHUtils.generatePCHObjectDirectory(objectDir, prefixFile, objectFile)

        then:
        generated.parentFile == objectDir

		memAlloc = &runtime.SimpleAllocator{}
	}
	prefixSize := uint64(len(s.prefix))

	var unk runtime.Unknown
	switch t := obj.(type) {
	case *runtime.Unknown:
		estimatedSize := prefixSize + uint64(t.Size())
		data := memAlloc.Allocate(estimatedSize)
		i, err := t.MarshalTo(data[prefixSize:])
		if err != nil {
			return err
		}
		copy(data, s.prefix)

		{sr("a", nameSize) + "/a", sr("a", nameSize), "a", true},
		{sr("a", prefixSize) + "/", "", "", false},
		{sr("a", prefixSize) + "/a", sr("a", prefixSize), "a", true},
		{sr("a", nameSize+1), "", "", false},
		{sr("/", nameSize+1), sr("/", nameSize-1), "/", true},
		{sr("a", prefixSize) + "/" + sr("b", nameSize),
			sr("a", prefixSize), sr("b", nameSize), true},
		{sr("a", prefixSize) + "//" + sr("b", nameSize), "", "", false},

		return "", "", false
	} else if length > prefixSize+1 {
		length = prefixSize + 1
	} else if name[length-1] == '/' {
		length--
	}

	i := strings.LastIndex(name[:length], "/")
	nlen := len(name) - i - 1 // nlen is length of suffix
	plen := i                 // plen is length of prefix
	if i <= 0 || nlen > nameSize || nlen == 0 || plen > prefixSize {
		return "", "", false
	}

)

// Size constants from various tar specifications.
const (
	blockSize  = 512 // Size of each block in a tar stream
	nameSize   = 100 // Max length of the name field in USTAR format
	prefixSize = 155 // Max length of the prefix field in USTAR format

	// Max length of a special file (PAX header, GNU long name or link).
	// This matches the limit used by libarchive.
	maxSpecialFileSize = 1 << 20
)

// is available
type PrefixableOptab struct {
	Optab
	minGOPPC64 int  // Minimum GOPPC64 required to support this.
	pfxsize    int8 // Instruction sequence size when prefixed opcodes are used
}

// The prefixable optab entry contains the pseudo-opcodes which generate relocations, or may generate
// a more efficient sequence of instructions if a prefixed version exists (ex. paddi instead of oris/ori/add).
//