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Package coverage

import "internal/coverage"
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Constants

CounterFilePref is the file prefix used when emitting coverage data output files. CounterFileTemplate describes the format of the file name: prefix followed by meta-file hash followed by process ID followed by emit UnixNanoTime.

const CounterFilePref = "covcounters"
const CounterFileRegexp = `^%s\.(\S+)\.(\d+)\.(\d+)+$`
const CounterFileTempl = "%s.%x.%d.%d"

CounterFileVersion stores the most recent counter data file version.

const CounterFileVersion = 1
const CovMetaHeaderSize = 16 + 4 + 4 + 4 + 4 + 4 + 4 + 4 // keep in sync with above
const FirstCtrOffset = 3
const FuncIdOffset = 2

MetaFilePref is a prefix used when emitting meta-data files; these files are of the form "covmeta.<hash>", where hash is a hash computed from the hashes of all the package meta-data symbols in the program.

const MetaFilePref = "covmeta"

MetaFileVersion contains the current (most recent) meta-data file version.

const MetaFileVersion = 1

Name of file within the "go test -cover" temp coverdir directory containing a list of meta-data files for packages being tested in a "go test -coverpkg=... ..." run. This constant is shared by the Go command and by the coverage runtime.

const MetaFilesFileName = "metafiles.txt"

NotHardCoded is a package pseudo-ID indicating that a given package is not part of the runtime and doesn't require a hard-coded ID.

const NotHardCoded = -1
const NumCtrsOffset = 0
const PkgIdOffset = 1

Variables

CovCounterMagic holds the magic string for a coverage counter-data file.

var CovCounterMagic = [4]byte{'\x00', '\x63', '\x77', '\x6d'}

CovMetaMagic holds the magic string for a meta-data file.

var CovMetaMagic = [4]byte{'\x00', '\x63', '\x76', '\x6d'}

func HardCodedPkgID

func HardCodedPkgID(pkgpath string) int

HardCodedPkgID returns the hard-coded ID for the specified package path, or -1 if we don't use a hard-coded ID. Hard-coded IDs start at -2 and decrease as we go down the list.

func Round4

func Round4(x int) int

type CounterFileFooter

CounterFileFooter appears at the tail end of a counter data file, and stores the number of segments it contains.

type CounterFileFooter struct {
    Magic [4]byte

    NumSegments uint32
    // contains filtered or unexported fields
}

type CounterFileHeader

CounterFileHeader stores files header information for a counter-data file.

type CounterFileHeader struct {
    Magic     [4]byte
    Version   uint32
    MetaHash  [16]byte
    CFlavor   CounterFlavor
    BigEndian bool
    // contains filtered or unexported fields
}

type CounterFlavor

CounterFlavor describes how function and counters are stored/represented in the counter section of the file.

type CounterFlavor uint8
const (
    // "Raw" representation: all values (pkg ID, func ID, num counters,
    // and counters themselves) are stored as uint32's.
    CtrRaw CounterFlavor = iota + 1

    // "ULeb" representation: all values (pkg ID, func ID, num counters,
    // and counters themselves) are stored with ULEB128 encoding.
    CtrULeb128
)

type CounterGranularity

CounterGranularity tracks the granularity of the coverage counters being used in a given coverage-instrumented program.

type CounterGranularity uint8
const (
    CtrGranularityInvalid CounterGranularity = iota
    CtrGranularityPerBlock
    CtrGranularityPerFunc
)

func (CounterGranularity) String

func (cm CounterGranularity) String() string

type CounterMode

CounterMode tracks the "flavor" of the coverage counters being used in a given coverage-instrumented program.

type CounterMode uint8
const (
    CtrModeInvalid  CounterMode = iota
    CtrModeSet                  // "set" mode
    CtrModeCount                // "count" mode
    CtrModeAtomic               // "atomic" mode
    CtrModeRegOnly              // registration-only pseudo-mode
    CtrModeTestMain             // testmain pseudo-mode
)

func ParseCounterMode

func ParseCounterMode(mode string) CounterMode

func (CounterMode) String

func (cm CounterMode) String() string

type CounterSegmentHeader

CounterSegmentHeader encapsulates information about a specific segment in a counter data file, which at the moment contains counters data from a single execution of a coverage-instrumented program. Following the segment header will be the string table and args table, and then (possibly) padding bytes to bring the byte size of the preamble up to a multiple of 4. Immediately following that will be the counter payloads.

The "args" section of a segment is used to store annotations describing where the counter data came from; this section is basically a series of key-value pairs (can be thought of as an encoded 'map[string]string'). At the moment we only write os.Args() data to this section, using pairs of the form "argc=<integer>", "argv0=<os.Args[0]>", "argv1=<os.Args[1]>", and so on. In the future the args table may also include things like GOOS/GOARCH values, and/or tags indicating which tests were run to generate the counter data.

type CounterSegmentHeader struct {
    FcnEntries uint64
    StrTabLen  uint32
    ArgsLen    uint32
}

type CoverableUnit

CoverableUnit describes the source characteristics of a single program unit for which we want to gather coverage info. Coverable units are either "simple" or "intraline"; a "simple" coverable unit corresponds to a basic block (region of straight-line code with no jumps or control transfers). An "intraline" unit corresponds to a logical clause nested within some other simple unit. A simple unit will have a zero Parent value; for an intraline unit NxStmts will be zero and Parent will be set to 1 plus the index of the containing simple statement. Example:

L7:   q := 1
L8:   x := (y == 101 || launch() == false)
L9:   r := x * 2

For the code above we would have three simple units (one for each line), then an intraline unit describing the "launch() == false" clause in line 8, with Parent pointing to the index of the line 8 unit in the units array.

Note: in the initial version of the coverage revamp, only simple units will be in use.

type CoverableUnit struct {
    StLine, StCol uint32
    EnLine, EnCol uint32
    NxStmts       uint32
    Parent        uint32
}

type FuncDesc

FuncDesc encapsulates the meta-data definitions for a single Go function. This version assumes that we're looking at a function before inlining; if we want to capture a post-inlining view of the world, the representations of source positions would need to be a good deal more complicated.

type FuncDesc struct {
    Funcname string
    Srcfile  string
    Units    []CoverableUnit
    Lit      bool // true if this is a function literal
}

type MetaFileCollection

MetaFilePaths contains information generated by the Go command and the read in by coverage test support functions within an executing "go test -cover" binary.

type MetaFileCollection struct {
    ImportPaths       []string
    MetaFileFragments []string
}

type MetaFileHeader

MetaFileHeader stores file header information for a meta-data file.

type MetaFileHeader struct {
    Magic        [4]byte
    Version      uint32
    TotalLength  uint64
    Entries      uint64
    MetaFileHash [16]byte
    StrTabOffset uint32
    StrTabLength uint32
    CMode        CounterMode
    CGranularity CounterGranularity
    // contains filtered or unexported fields
}

type MetaSymbolHeader

MetaSymbolHeader stores header information for a single meta-data blob, e.g. the coverage meta-data payload computed for a given Go package.

type MetaSymbolHeader struct {
    Length     uint32 // size of meta-symbol payload in bytes
    PkgName    uint32 // string table index
    PkgPath    uint32 // string table index
    ModulePath uint32 // string table index
    MetaHash   [16]byte

    NumFiles uint32
    NumFuncs uint32
    // contains filtered or unexported fields
}

Subdirectories

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