gowebbuild/vendor/github.com/evanw/esbuild/internal/graph/graph.go

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package graph
// This graph represents the set of files that the linker operates on. Each
// linker has a separate one of these graphs (there is one linker when code
// splitting is on, but one linker per entry point when code splitting is off).
//
// The input data to the linker constructor must be considered immutable because
// it's shared between linker invocations and is also stored in the cache for
// incremental builds.
//
// The linker constructor makes a shallow clone of the input data and is careful
// to pre-clone ahead of time the AST fields that it may modify. The Go language
// doesn't have any type system features for immutability so this has to be
// manually enforced. Please be careful.
import (
"sort"
"sync"
"github.com/evanw/esbuild/internal/ast"
"github.com/evanw/esbuild/internal/helpers"
"github.com/evanw/esbuild/internal/js_ast"
"github.com/evanw/esbuild/internal/logger"
"github.com/evanw/esbuild/internal/runtime"
)
type entryPointKind uint8
const (
entryPointNone entryPointKind = iota
entryPointUserSpecified
entryPointDynamicImport
)
type LinkerFile struct {
InputFile InputFile
// This holds all entry points that can reach this file. It will be used to
// assign the parts in this file to a chunk.
EntryBits helpers.BitSet
// This is lazily-allocated because it's only needed if there are warnings
// logged, which should be relatively rare.
lazyLineColumnTracker *logger.LineColumnTracker
// The minimum number of links in the module graph to get from an entry point
// to this file
DistanceFromEntryPoint uint32
// If "entryPointKind" is not "entryPointNone", this is the index of the
// corresponding entry point chunk.
EntryPointChunkIndex uint32
// This file is an entry point if and only if this is not "entryPointNone".
// Note that dynamically-imported files are allowed to also be specified by
// the user as top-level entry points, so some dynamically-imported files
// may be "entryPointUserSpecified" instead of "entryPointDynamicImport".
entryPointKind entryPointKind
// This is true if this file has been marked as live by the tree shaking
// algorithm.
IsLive bool
}
func (f *LinkerFile) IsEntryPoint() bool {
return f.entryPointKind != entryPointNone
}
func (f *LinkerFile) IsUserSpecifiedEntryPoint() bool {
return f.entryPointKind == entryPointUserSpecified
}
// Note: This is not guarded by a mutex. Make sure this isn't called from a
// parallel part of the code.
func (f *LinkerFile) LineColumnTracker() *logger.LineColumnTracker {
if f.lazyLineColumnTracker == nil {
tracker := logger.MakeLineColumnTracker(&f.InputFile.Source)
f.lazyLineColumnTracker = &tracker
}
return f.lazyLineColumnTracker
}
type EntryPoint struct {
// This may be an absolute path or a relative path. If absolute, it will
// eventually be turned into a relative path by computing the path relative
// to the "outbase" directory. Then this relative path will be joined onto
// the "outdir" directory to form the final output path for this entry point.
OutputPath string
// This is the source index of the entry point. This file must have a valid
// entry point kind (i.e. not "none").
SourceIndex uint32
// Manually specified output paths are ignored when computing the default
// "outbase" directory, which is computed as the lowest common ancestor of
// all automatically generated output paths.
OutputPathWasAutoGenerated bool
}
type LinkerGraph struct {
Files []LinkerFile
entryPoints []EntryPoint
Symbols js_ast.SymbolMap
// We should avoid traversing all files in the bundle, because the linker
// should be able to run a linking operation on a large bundle where only
// a few files are needed (e.g. an incremental compilation scenario). This
// holds all files that could possibly be reached through the entry points.
// If you need to iterate over all files in the linking operation, iterate
// over this array. This array is also sorted in a deterministic ordering
// to help ensure deterministic builds (source indices are random).
ReachableFiles []uint32
// This maps from unstable source index to stable reachable file index. This
// is useful as a deterministic key for sorting if you need to sort something
// containing a source index (such as "js_ast.Ref" symbol references).
StableSourceIndices []uint32
}
func CloneLinkerGraph(
inputFiles []InputFile,
reachableFiles []uint32,
originalEntryPoints []EntryPoint,
codeSplitting bool,
) LinkerGraph {
entryPoints := append([]EntryPoint{}, originalEntryPoints...)
symbols := js_ast.NewSymbolMap(len(inputFiles))
files := make([]LinkerFile, len(inputFiles))
// Mark all entry points so we don't add them again for import() expressions
for _, entryPoint := range entryPoints {
files[entryPoint.SourceIndex].entryPointKind = entryPointUserSpecified
}
// Clone various things since we may mutate them later. Do this in parallel
// for a speedup (around ~2x faster for this function in the three.js
// benchmark on a 6-core laptop).
var dynamicImportEntryPoints []uint32
var dynamicImportEntryPointsMutex sync.Mutex
waitGroup := sync.WaitGroup{}
waitGroup.Add(len(reachableFiles))
stableSourceIndices := make([]uint32, len(inputFiles))
for stableIndex, sourceIndex := range reachableFiles {
// Create a way to convert source indices to a stable ordering
stableSourceIndices[sourceIndex] = uint32(stableIndex)
go func(sourceIndex uint32) {
file := &files[sourceIndex]
file.InputFile = inputFiles[sourceIndex]
switch repr := file.InputFile.Repr.(type) {
case *JSRepr:
// Clone the representation
{
clone := *repr
repr = &clone
file.InputFile.Repr = repr
}
// Clone the symbol map
fileSymbols := append([]js_ast.Symbol{}, repr.AST.Symbols...)
symbols.SymbolsForSource[sourceIndex] = fileSymbols
repr.AST.Symbols = nil
// Clone the parts
repr.AST.Parts = append([]js_ast.Part{}, repr.AST.Parts...)
for i := range repr.AST.Parts {
part := &repr.AST.Parts[i]
clone := make(map[js_ast.Ref]js_ast.SymbolUse, len(part.SymbolUses))
for ref, uses := range part.SymbolUses {
clone[ref] = uses
}
part.SymbolUses = clone
part.Dependencies = append([]js_ast.Dependency{}, part.Dependencies...)
}
// Clone the import records
repr.AST.ImportRecords = append([]ast.ImportRecord{}, repr.AST.ImportRecords...)
// Add dynamic imports as additional entry points if code splitting is active
if codeSplitting {
for importRecordIndex := range repr.AST.ImportRecords {
if record := &repr.AST.ImportRecords[importRecordIndex]; record.SourceIndex.IsValid() && record.Kind == ast.ImportDynamic {
dynamicImportEntryPointsMutex.Lock()
dynamicImportEntryPoints = append(dynamicImportEntryPoints, record.SourceIndex.GetIndex())
dynamicImportEntryPointsMutex.Unlock()
}
}
}
// Clone the import map
namedImports := make(map[js_ast.Ref]js_ast.NamedImport, len(repr.AST.NamedImports))
for k, v := range repr.AST.NamedImports {
namedImports[k] = v
}
repr.AST.NamedImports = namedImports
// Clone the export map
resolvedExports := make(map[string]ExportData)
for alias, name := range repr.AST.NamedExports {
resolvedExports[alias] = ExportData{
Ref: name.Ref,
SourceIndex: sourceIndex,
NameLoc: name.AliasLoc,
}
}
// Clone the top-level scope so we can generate more variables
{
new := &js_ast.Scope{}
*new = *repr.AST.ModuleScope
new.Generated = append([]js_ast.Ref{}, new.Generated...)
repr.AST.ModuleScope = new
}
// Also associate some default metadata with the file
repr.Meta.ResolvedExports = resolvedExports
repr.Meta.IsProbablyTypeScriptType = make(map[js_ast.Ref]bool)
repr.Meta.ImportsToBind = make(map[js_ast.Ref]ImportData)
case *CSSRepr:
// Clone the representation
{
clone := *repr
repr = &clone
file.InputFile.Repr = repr
}
// Clone the import records
repr.AST.ImportRecords = append([]ast.ImportRecord{}, repr.AST.ImportRecords...)
}
// All files start off as far as possible from an entry point
file.DistanceFromEntryPoint = ^uint32(0)
waitGroup.Done()
}(sourceIndex)
}
waitGroup.Wait()
// Process dynamic entry points after merging control flow again
stableEntryPoints := make([]int, 0, len(dynamicImportEntryPoints))
for _, sourceIndex := range dynamicImportEntryPoints {
if otherFile := &files[sourceIndex]; otherFile.entryPointKind == entryPointNone {
stableEntryPoints = append(stableEntryPoints, int(stableSourceIndices[sourceIndex]))
otherFile.entryPointKind = entryPointDynamicImport
}
}
// Make sure to add dynamic entry points in a deterministic order
sort.Ints(stableEntryPoints)
for _, stableIndex := range stableEntryPoints {
entryPoints = append(entryPoints, EntryPoint{SourceIndex: reachableFiles[stableIndex]})
}
// Allocate the entry bit set now that the number of entry points is known
bitCount := uint(len(entryPoints))
for _, sourceIndex := range reachableFiles {
files[sourceIndex].EntryBits = helpers.NewBitSet(bitCount)
}
return LinkerGraph{
Symbols: symbols,
entryPoints: entryPoints,
Files: files,
ReachableFiles: reachableFiles,
StableSourceIndices: stableSourceIndices,
}
}
// Prevent packages that depend on us from adding or removing entry points
func (g *LinkerGraph) EntryPoints() []EntryPoint {
return g.entryPoints
}
func (g *LinkerGraph) AddPartToFile(sourceIndex uint32, part js_ast.Part) uint32 {
// Invariant: this map is never null
if part.SymbolUses == nil {
part.SymbolUses = make(map[js_ast.Ref]js_ast.SymbolUse)
}
repr := g.Files[sourceIndex].InputFile.Repr.(*JSRepr)
partIndex := uint32(len(repr.AST.Parts))
repr.AST.Parts = append(repr.AST.Parts, part)
// Invariant: the parts for all top-level symbols can be found in the file-level map
for _, declaredSymbol := range part.DeclaredSymbols {
if declaredSymbol.IsTopLevel {
// Check for an existing overlay
partIndices, ok := repr.Meta.TopLevelSymbolToPartsOverlay[declaredSymbol.Ref]
// If missing, initialize using the original values from the parser
if !ok {
partIndices = append(partIndices, repr.AST.TopLevelSymbolToPartsFromParser[declaredSymbol.Ref]...)
}
// Add this part to the overlay
partIndices = append(partIndices, partIndex)
if repr.Meta.TopLevelSymbolToPartsOverlay == nil {
repr.Meta.TopLevelSymbolToPartsOverlay = make(map[js_ast.Ref][]uint32)
}
repr.Meta.TopLevelSymbolToPartsOverlay[declaredSymbol.Ref] = partIndices
}
}
return partIndex
}
func (g *LinkerGraph) GenerateNewSymbol(sourceIndex uint32, kind js_ast.SymbolKind, originalName string) js_ast.Ref {
sourceSymbols := &g.Symbols.SymbolsForSource[sourceIndex]
ref := js_ast.Ref{
SourceIndex: sourceIndex,
InnerIndex: uint32(len(*sourceSymbols)),
}
*sourceSymbols = append(*sourceSymbols, js_ast.Symbol{
Kind: kind,
OriginalName: originalName,
Link: js_ast.InvalidRef,
})
generated := &g.Files[sourceIndex].InputFile.Repr.(*JSRepr).AST.ModuleScope.Generated
*generated = append(*generated, ref)
return ref
}
func (g *LinkerGraph) GenerateSymbolImportAndUse(
sourceIndex uint32,
partIndex uint32,
ref js_ast.Ref,
useCount uint32,
sourceIndexToImportFrom uint32,
) {
if useCount == 0 {
return
}
repr := g.Files[sourceIndex].InputFile.Repr.(*JSRepr)
part := &repr.AST.Parts[partIndex]
// Mark this symbol as used by this part
use := part.SymbolUses[ref]
use.CountEstimate += useCount
part.SymbolUses[ref] = use
// Uphold invariants about the CommonJS "exports" and "module" symbols
if ref == repr.AST.ExportsRef {
repr.AST.UsesExportsRef = true
}
if ref == repr.AST.ModuleRef {
repr.AST.UsesModuleRef = true
}
// Track that this specific symbol was imported
if sourceIndexToImportFrom != sourceIndex {
repr.Meta.ImportsToBind[ref] = ImportData{
SourceIndex: sourceIndexToImportFrom,
Ref: ref,
}
}
// Pull in all parts that declare this symbol
targetRepr := g.Files[sourceIndexToImportFrom].InputFile.Repr.(*JSRepr)
for _, partIndex := range targetRepr.TopLevelSymbolToParts(ref) {
part.Dependencies = append(part.Dependencies, js_ast.Dependency{
SourceIndex: sourceIndexToImportFrom,
PartIndex: partIndex,
})
}
}
func (g *LinkerGraph) GenerateRuntimeSymbolImportAndUse(
sourceIndex uint32,
partIndex uint32,
name string,
useCount uint32,
) {
if useCount == 0 {
return
}
runtimeRepr := g.Files[runtime.SourceIndex].InputFile.Repr.(*JSRepr)
ref := runtimeRepr.AST.NamedExports[name].Ref
g.GenerateSymbolImportAndUse(sourceIndex, partIndex, ref, useCount, runtime.SourceIndex)
}