Shared     = flag.Bool("shared", false, "generate code that can be linked into a shared library")
	Dynlink    = flag.Bool("dynlink", false, "support references to Go symbols defined in other shared libraries")
	Linkshared = flag.Bool("linkshared", false, "generate code that will be linked against Go shared libraries")

		return
	case "GLOBL", "PCDATA":
		// No text definitions or symbol references.
	case "DATA", "FUNCDATA":
		// For DATA, operands[0] is defined symbol.
		// For FUNCDATA, operands[0] is an immediate constant.
		// Remaining operands may have references.
		if len(operands) < 2 {
			return
		}
		operands = operands[1:]
	}
	// Search for symbol references.
	for _, op := range operands {
		p.start(op)

	void _cgo_reginit(void) { }

The extra functions here are stubs to satisfy the references in the C
code generated for gcc. The build process links this stub, along with
_cgo_export.c and *.cgo2.c, into a dynamic executable and then lets
cgo examine the executable. Cgo records the list of shared library
references and resolved names and writes them into a new file
_cgo_import.go, which looks like:

		}
	}
}

// Save various references we are going to need later.
func (f *File) saveExprs(x interface{}, context astContext) {
	switch x := x.(type) {
	case *ast.Expr:
		switch (*x).(type) {
		case *ast.SelectorExpr:
			f.saveRef(x, context)
		}
	case *ast.CallExpr:
		f.saveCall(x, context)
	}
}

// Save references to C.xxx for later processing.

	} else if escaped {
		err = errors.New("unfinished escaping")
	}
	return args, err
}

// Translate rewrites f.AST, the original Go input, to remove
// references to the imported package C, replacing them with
// references to the equivalent Go types, functions, and variables.
func (p *Package) Translate(f *File) {
	for _, cref := range f.Ref {
		// Convert C.ulong to C.unsigned long, etc.

	// the format has several limitations making it unsuitable for some usages.
	// Most notably, it cannot support sparse files, files larger than 8GiB,
	// filenames larger than 256 characters, and non-ASCII filenames.
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	FormatUSTAR

	// FormatPAX represents the PAX header format defined in POSIX.1-2001.
	//

			t.Errorf("Clone(%#v) return value should not be equal to nil slice.", input)
		}

		if cap(input) != 0 && unsafe.SliceData(input) == unsafe.SliceData(clone) {
			t.Errorf("Clone(%q) return value should not reference inputs backing memory.", input)
		}
	}

		after consulting $GOROOT/pkg/$GOOS_$GOARCH.
	-S
		Print assembly and machine code.
	-V
		Print assembler version and exit.
	-debug
		Dump instructions as they are parsed.
	-dynlink
		Support references to Go symbols defined in other shared libraries.
	-e
		No limit on number of errors reported.
	-gensymabis
		Write symbol ABI information to output file. Don't assemble.
	-o file

	ErrWriteAfterClose = errors.New("archive/tar: write after close")
	ErrInsecurePath    = errors.New("archive/tar: insecure file path")
	errMissData        = errors.New("archive/tar: sparse file references non-existent data")
	errUnrefData       = errors.New("archive/tar: sparse file contains unreferenced data")
	errWriteHole       = errors.New("archive/tar: write non-NUL byte in sparse hole")
)

type headerError []string

	case "line":
		in.line()
	case "undef":
		in.undef()
	default:
		in.Error("unexpected token after '#':", in.Stack.Text())
	}
	return true
}

// macroName returns the name for the macro being referenced.
func (in *Input) macroName() string {
	// We use the Stack's input method; no macro processing at this stage.
	tok := in.Stack.Next()
	if tok != scanner.Ident {
		in.expectText("expected identifier after # directive")