C.sizeof_struct_stat.

A C function may be declared in the Go file with a parameter type of
the special name _GoString_. This function may be called with an
ordinary Go string value. The string length, and a pointer to the
string contents, may be accessed by calling the C functions

	size_t _GoStringLen(_GoString_ s);
	const char *_GoStringPtr(_GoString_ s);

These functions are only available in the preamble, not in other C

			if c.incompleteStructs[tag] {
				tt.Go = c.Ident(incomplete)
			}
			typedef[name.Name] = &tt
		}

	case *dwarf.TypedefType:
		// Record typedef for printing.
		if dt.Name == "_GoString_" {
			// Special C name for Go string type.
			// Knows string layout used by compilers: pointer plus length,
			// which rounds up to 2 pointers after alignment.
			t.Go = c.string
			t.Size = c.ptrSize * 2

}

int
returnAfterGrowFromGo(void)
{
	extern int goReturnVal(void);
	return goReturnVal();
}

void
callGoWithString(void)
{
	extern void goWithString(GoString);
	const char *str = "string passed from C to Go";
	goWithString((GoString){str, strlen(str)});

pkg time, const Layout = "01/02 03:04:05PM '06 -0700"
pkg time, const Layout ideal-string
pkg time, func UnixMicro(int64) Time
pkg time, func UnixMilli(int64) Time
pkg time, method (Time) GoString() string
pkg time, method (Time) IsDST() bool
pkg time, method (Time) UnixMicro() int64

pkg debug/elf, const R_LARCH_TLS_TPREL32 R_LARCH #46229
pkg debug/elf, const R_LARCH_TLS_TPREL64 = 11 #46229
pkg debug/elf, const R_LARCH_TLS_TPREL64 R_LARCH #46229
pkg debug/elf, method (R_LARCH) GoString() string #46229
pkg debug/elf, method (R_LARCH) String() string #46229
pkg debug/elf, type R_LARCH int #46229
pkg debug/pe, const IMAGE_COMDAT_SELECT_ANY = 2 #51868

pkg debug/elf, const DF_1_WEAKFILTER DynFlag1 #56887
pkg debug/elf, const R_PPC64_REL24_P9NOTOC = 124 #60348
pkg debug/elf, const R_PPC64_REL24_P9NOTOC R_PPC64 #60348
pkg debug/elf, method (DynFlag1) GoString() string #56887
pkg debug/elf, method (DynFlag1) String() string #56887
pkg debug/elf, method (*File) DynValue(DynTag) ([]uint64, error) #56892
pkg debug/elf, type DynFlag1 uint32 #56887