// invocation of F then behaves like a call to panic, terminating G's
// execution and running any deferred functions. This continues until all
// functions in the executing goroutine have stopped, in reverse order. At
// that point, the program is terminated with a non-zero exit code. This
// termination sequence is called panicking and can be controlled by the
// built-in function recover.
//

error messages, debug information, and object files. In practice,
parsing these is significantly less work and more robust than parsing
C source.

Cgo first invokes gcc -E -dM on the preamble, in order to find out
about simple #defines for constants and the like. These are recorded
for later use.

Next, cgo needs to identify the kinds for each identifier. For the
identifiers C.foo, cgo generates this C program:

	// Since the Reader liberally reads some non-compliant files,
	// it is possible for this to be FormatUnknown.
	//
	// If the format is unspecified when Writer.WriteHeader is called,
	// then it uses the first format (in the order of USTAR, PAX, GNU)
	// capable of encoding this Header (see Format).
	Format Format
}

// sparseEntry represents a Length-sized fragment at Offset in the file.
type sparseEntry struct{ Offset, Length int64 }

		if err != nil {
			return nil, ErrHeader
		}
		sbuf = residual

		switch key {
		case paxGNUSparseOffset, paxGNUSparseNumBytes:
			// Validate sparse header order and value.
			if (len(sparseMap)%2 == 0 && key != paxGNUSparseOffset) ||
				(len(sparseMap)%2 == 1 && key != paxGNUSparseNumBytes) ||
				strings.Contains(value, ",") {
				return nil, ErrHeader
			}

	//
	//	* Many ZIP readers still do not support UTF-8.
	//	* If the UTF-8 flag is cleared, several readers simply interpret the
	//	name and comment fields as whatever the local system encoding is.
	//
	// In order to avoid breaking readers without UTF-8 support,
	// we avoid setting the UTF-8 flag if the strings are CP-437 compatible.
	// However, if the strings require multibyte UTF-8 encoding and is a