}
	return args
}

// CFlags returns the flags to use when invoking the C, C++ or Fortran compilers, or cgo.
func (b *Builder) CFlags(p *load.Package) (cppflags, cflags, cxxflags, fflags, ldflags []string, err error) {
	if cppflags, err = buildFlags("CPPFLAGS", "", p.CgoCPPFLAGS, checkCompilerFlags); err != nil {
		return
	}
	if cflags, err = buildFlags("CFLAGS", DefaultCFlags, p.CgoCFLAGS, checkCompilerFlags); err != nil {

		C code.
	CGO_CFLAGS_ALLOW
		A regular expression specifying additional flags to allow
		to appear in #cgo CFLAGS source code directives.
		Does not apply to the CGO_CFLAGS environment variable.
	CGO_CFLAGS_DISALLOW
		A regular expression specifying flags that must be disallowed
		from appearing in #cgo CFLAGS source code directives.
		Does not apply to the CGO_CFLAGS environment variable.

//		C code.
//	CGO_CFLAGS_ALLOW
//		A regular expression specifying additional flags to allow
//		to appear in #cgo CFLAGS source code directives.
//		Does not apply to the CGO_CFLAGS environment variable.
//	CGO_CFLAGS_DISALLOW
//		A regular expression specifying flags that must be disallowed
//		from appearing in #cgo CFLAGS source code directives.
//		Does not apply to the CGO_CFLAGS environment variable.