// license that can be found in the LICENSE file.

package runtime

import (
	"internal/coverage/rtcov"
	"unsafe"
)

//go:linkname coverage_getCovCounterList internal/coverage/cfile.getCovCounterList
func coverage_getCovCounterList() []rtcov.CovCounterBlob {
	res := []rtcov.CovCounterBlob{}
	u32sz := unsafe.Sizeof(uint32(0))
	for datap := &firstmoduledata; datap != nil; datap = datap.next {

		return fmt.Errorf("WriteCounters invoked for program built with -covermode=%s (please use -covermode=atomic)", cmode.String())
	}
	// Ask the runtime for the list of coverage counter symbols.
	cl := getCovCounterList()
	if len(cl) == 0 {
		return fmt.Errorf("program not built with -cover")
	}
	if !finalHashComputed {
		return fmt.Errorf("meta-data not written yet, unable to write counter data")
	}

// emitted at the end of code coverage testing runs, from instrumented
// executables.

// getCovCounterList returns a list of counter-data blobs registered
// for the currently executing instrumented program. It is defined in the
// runtime.
//
//go:linkname getCovCounterList
func getCovCounterList() []rtcov.CovCounterBlob

// emitState holds useful state information during the emit process.
//

// result it returns will be less accurate (more "slop") due to the
// fact that we don't look at the meta data to see how many statements
// are associated with each counter.
func Snapshot() float64 {
	cl := getCovCounterList()
	if len(cl) == 0 {
		// no work to do here.
		return 0.0
	}

	tot := uint64(0)
	totExec := uint64(0)
	for _, c := range cl {