goc/pkg/build/cover.go

package build

import (
	"crypto/sha256"
	"fmt"
	"path"
	"time"
)

// declareCoverVars attaches the required cover variables names
// to the files, to be used when annotating the files.
func declareCoverVars(p *Package) map[string]*FileVar {
	coverVars := make(map[string]*FileVar)
	coverIndex := 0
	// We create the cover counters as new top-level variables in the package.
	// We need to avoid collisions with user variables (GoCover_0 is unlikely but still)
	// and more importantly with dot imports of other covered packages,
	// so we append 12 hex digits from the SHA-256 of the import path.
	// The point is only to avoid accidents, not to defeat users determined to
	// break things.
	sum := sha256.Sum256([]byte(p.ImportPath))
	h := fmt.Sprintf("%x", sum[:6])
	for _, file := range p.GoFiles {
		// These names appear in the cmd/cover HTML interface.
		var longFile = path.Join(p.ImportPath, file)
		coverVars[file] = &FileVar{
			File: longFile,
			Var:  fmt.Sprintf("GoCover_%d_%x", coverIndex, h),
		}
		coverIndex++
	}

	for _, file := range p.CgoFiles {
		// These names appear in the cmd/cover HTML interface.
		var longFile = path.Join(p.ImportPath, file)
		coverVars[file] = &FileVar{
			File: longFile,
			Var:  fmt.Sprintf("GoCover_%d_%x", coverIndex, h),
		}
		coverIndex++
	}

	return coverVars
}

// PackageCover holds all the generate coverage variables of a package
type PackageCover struct {
	Package *Package
	Vars    map[string]*FileVar
}

// FileVar holds the name of the generated coverage variables targeting the named file.
type FileVar struct {
	File string // 这里其实不是文件名，是 importpath + filename
	Var  string
}

// Package map a package output by go list
// this is subset of package struct in: https://github.com/golang/go/blob/master/src/cmd/go/internal/load/pkg.go#L58
type Package struct {
	Dir        string `json:"Dir"`        // directory containing package sources
	ImportPath string `json:"ImportPath"` // import path of package in dir
	Name       string `json:"Name"`       // package name
	Target     string `json:",omitempty"` // installed target for this package (may be executable)
	Root       string `json:",omitempty"` // Go root, Go path dir, or module root dir containing this package

	Module   *ModulePublic `json:",omitempty"`         // info about package's module, if any
	Goroot   bool          `json:"Goroot,omitempty"`   // is this package in the Go root?
	Standard bool          `json:"Standard,omitempty"` // is this package part of the standard Go library?
	DepOnly  bool          `json:"DepOnly,omitempty"`  // package is only a dependency, not explicitly listed

	// Source files
	GoFiles  []string `json:"GoFiles,omitempty"`  // .go source files (excluding CgoFiles, TestGoFiles, XTestGoFiles)
	CgoFiles []string `json:"CgoFiles,omitempty"` // .go source files that import "C"

	// Dependency information
	Deps      []string          `json:"Deps,omitempty"` // all (recursively) imported dependencies
	Imports   []string          `json:",omitempty"`     // import paths used by this package
	ImportMap map[string]string `json:",omitempty"`     // map from source import to ImportPath (identity entries omitted)

	// Error information
	Incomplete bool            `json:"Incomplete,omitempty"` // this package or a dependency has an error
	Error      *PackageError   `json:"Error,omitempty"`      // error loading package
	DepsErrors []*PackageError `json:"DepsErrors,omitempty"` // errors loading dependencies
}

// ModulePublic represents the package info of a module
type ModulePublic struct {
	Path      string        `json:",omitempty"` // module path
	Version   string        `json:",omitempty"` // module version
	Versions  []string      `json:",omitempty"` // available module versions
	Replace   *ModulePublic `json:",omitempty"` // replaced by this module
	Time      *time.Time    `json:",omitempty"` // time version was created
	Update    *ModulePublic `json:",omitempty"` // available update (with -u)
	Main      bool          `json:",omitempty"` // is this the main module?
	Indirect  bool          `json:",omitempty"` // module is only indirectly needed by main module
	Dir       string        `json:",omitempty"` // directory holding local copy of files, if any
	GoMod     string        `json:",omitempty"` // path to go.mod file describing module, if any
	GoVersion string        `json:",omitempty"` // go version used in module
	Error     *ModuleError  `json:",omitempty"` // error loading module
}

// ModuleError represents the error loading module
type ModuleError struct {
	Err string // error text
}

// PackageError is the error info for a package when list failed
type PackageError struct {
	ImportStack []string // shortest path from package named on command line to this one
	Pos         string   // position of error (if present, file:line:col)
	Err         string   // the error itself
}