From 47ab3d4a42e9ab51c465c4322d2ec233f6324e6b Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:16:40 +0200 Subject: Adding upstream version 1.18.10. Signed-off-by: Daniel Baumann --- src/cmd/compile/internal/noder/unified.go | 334 ++++++++++++++++++++++++++++++ 1 file changed, 334 insertions(+) create mode 100644 src/cmd/compile/internal/noder/unified.go (limited to 'src/cmd/compile/internal/noder/unified.go') diff --git a/src/cmd/compile/internal/noder/unified.go b/src/cmd/compile/internal/noder/unified.go new file mode 100644 index 0000000..ec0012d --- /dev/null +++ b/src/cmd/compile/internal/noder/unified.go @@ -0,0 +1,334 @@ +// UNREVIEWED + +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package noder + +import ( + "bytes" + "fmt" + "internal/goversion" + "io" + "runtime" + "sort" + + "cmd/compile/internal/base" + "cmd/compile/internal/inline" + "cmd/compile/internal/ir" + "cmd/compile/internal/typecheck" + "cmd/compile/internal/types" + "cmd/compile/internal/types2" + "cmd/internal/src" +) + +// localPkgReader holds the package reader used for reading the local +// package. It exists so the unified IR linker can refer back to it +// later. +var localPkgReader *pkgReader + +// unified construct the local package's IR from syntax's AST. +// +// The pipeline contains 2 steps: +// +// (1) Generate package export data "stub". +// +// (2) Generate package IR from package export data. +// +// The package data "stub" at step (1) contains everything from the local package, +// but nothing that have been imported. When we're actually writing out export data +// to the output files (see writeNewExport function), we run the "linker", which does +// a few things: +// +// + Updates compiler extensions data (e.g., inlining cost, escape analysis results). +// +// + Handles re-exporting any transitive dependencies. +// +// + Prunes out any unnecessary details (e.g., non-inlineable functions, because any +// downstream importers only care about inlinable functions). +// +// The source files are typechecked twice, once before writing export data +// using types2 checker, once after read export data using gc/typecheck. +// This duplication of work will go away once we always use types2 checker, +// we can remove the gc/typecheck pass. The reason it is still here: +// +// + It reduces engineering costs in maintaining a fork of typecheck +// (e.g., no need to backport fixes like CL 327651). +// +// + It makes it easier to pass toolstash -cmp. +// +// + Historically, we would always re-run the typechecker after import, even though +// we know the imported data is valid. It's not ideal, but also not causing any +// problem either. +// +// + There's still transformation that being done during gc/typecheck, like rewriting +// multi-valued function call, or transform ir.OINDEX -> ir.OINDEXMAP. +// +// Using syntax+types2 tree, which already has a complete representation of generics, +// the unified IR has the full typed AST for doing introspection during step (1). +// In other words, we have all necessary information to build the generic IR form +// (see writer.captureVars for an example). +func unified(noders []*noder) { + inline.NewInline = InlineCall + + if !quirksMode() { + writeNewExportFunc = writeNewExport + } else if base.Flag.G != 0 { + base.Errorf("cannot use -G and -d=quirksmode together") + } + + newReadImportFunc = func(data string, pkg1 *types.Pkg, ctxt *types2.Context, packages map[string]*types2.Package) (pkg2 *types2.Package, err error) { + pr := newPkgDecoder(pkg1.Path, data) + + // Read package descriptors for both types2 and compiler backend. + readPackage(newPkgReader(pr), pkg1) + pkg2 = readPackage2(ctxt, packages, pr) + return + } + + data := writePkgStub(noders) + + // We already passed base.Flag.Lang to types2 to handle validating + // the user's source code. Bump it up now to the current version and + // re-parse, so typecheck doesn't complain if we construct IR that + // utilizes newer Go features. + base.Flag.Lang = fmt.Sprintf("go1.%d", goversion.Version) + types.ParseLangFlag() + + assert(types.LocalPkg.Path == "") + types.LocalPkg.Height = 0 // reset so pkgReader.pkgIdx doesn't complain + target := typecheck.Target + + typecheck.TypecheckAllowed = true + + localPkgReader = newPkgReader(newPkgDecoder(types.LocalPkg.Path, data)) + readPackage(localPkgReader, types.LocalPkg) + + r := localPkgReader.newReader(relocMeta, privateRootIdx, syncPrivate) + r.pkgInit(types.LocalPkg, target) + + // Type-check any top-level assignments. We ignore non-assignments + // here because other declarations are typechecked as they're + // constructed. + for i, ndecls := 0, len(target.Decls); i < ndecls; i++ { + switch n := target.Decls[i]; n.Op() { + case ir.OAS, ir.OAS2: + target.Decls[i] = typecheck.Stmt(n) + } + } + + // Don't use range--bodyIdx can add closures to todoBodies. + for len(todoBodies) > 0 { + // The order we expand bodies doesn't matter, so pop from the end + // to reduce todoBodies reallocations if it grows further. + fn := todoBodies[len(todoBodies)-1] + todoBodies = todoBodies[:len(todoBodies)-1] + + pri, ok := bodyReader[fn] + assert(ok) + pri.funcBody(fn) + + // Instantiated generic function: add to Decls for typechecking + // and compilation. + if fn.OClosure == nil && len(pri.dict.targs) != 0 { + target.Decls = append(target.Decls, fn) + } + } + todoBodies = nil + todoBodiesDone = true + + // Check that nothing snuck past typechecking. + for _, n := range target.Decls { + if n.Typecheck() == 0 { + base.FatalfAt(n.Pos(), "missed typecheck: %v", n) + } + + // For functions, check that at least their first statement (if + // any) was typechecked too. + if fn, ok := n.(*ir.Func); ok && len(fn.Body) != 0 { + if stmt := fn.Body[0]; stmt.Typecheck() == 0 { + base.FatalfAt(stmt.Pos(), "missed typecheck: %v", stmt) + } + } + } + + base.ExitIfErrors() // just in case +} + +// writePkgStub type checks the given parsed source files, +// writes an export data package stub representing them, +// and returns the result. +func writePkgStub(noders []*noder) string { + m, pkg, info := checkFiles(noders) + + pw := newPkgWriter(m, pkg, info) + + pw.collectDecls(noders) + + publicRootWriter := pw.newWriter(relocMeta, syncPublic) + privateRootWriter := pw.newWriter(relocMeta, syncPrivate) + + assert(publicRootWriter.idx == publicRootIdx) + assert(privateRootWriter.idx == privateRootIdx) + + { + w := publicRootWriter + w.pkg(pkg) + w.bool(false) // has init; XXX + + scope := pkg.Scope() + names := scope.Names() + w.len(len(names)) + for _, name := range scope.Names() { + w.obj(scope.Lookup(name), nil) + } + + w.sync(syncEOF) + w.flush() + } + + { + w := privateRootWriter + w.pkgInit(noders) + w.flush() + } + + var sb bytes.Buffer // TODO(mdempsky): strings.Builder after #44505 is resolved + pw.dump(&sb) + + // At this point, we're done with types2. Make sure the package is + // garbage collected. + freePackage(pkg) + + return sb.String() +} + +// freePackage ensures the given package is garbage collected. +func freePackage(pkg *types2.Package) { + // The GC test below relies on a precise GC that runs finalizers as + // soon as objects are unreachable. Our implementation provides + // this, but other/older implementations may not (e.g., Go 1.4 does + // not because of #22350). To avoid imposing unnecessary + // restrictions on the GOROOT_BOOTSTRAP toolchain, we skip the test + // during bootstrapping. + if base.CompilerBootstrap { + return + } + + // Set a finalizer on pkg so we can detect if/when it's collected. + done := make(chan struct{}) + runtime.SetFinalizer(pkg, func(*types2.Package) { close(done) }) + + // Important: objects involved in cycles are not finalized, so zero + // out pkg to break its cycles and allow the finalizer to run. + *pkg = types2.Package{} + + // It typically takes just 1 or 2 cycles to release pkg, but it + // doesn't hurt to try a few more times. + for i := 0; i < 10; i++ { + select { + case <-done: + return + default: + runtime.GC() + } + } + + base.Fatalf("package never finalized") +} + +func readPackage(pr *pkgReader, importpkg *types.Pkg) { + r := pr.newReader(relocMeta, publicRootIdx, syncPublic) + + pkg := r.pkg() + assert(pkg == importpkg) + + if r.bool() { + sym := pkg.Lookup(".inittask") + task := ir.NewNameAt(src.NoXPos, sym) + task.Class = ir.PEXTERN + sym.Def = task + } + + for i, n := 0, r.len(); i < n; i++ { + r.sync(syncObject) + assert(!r.bool()) + idx := r.reloc(relocObj) + assert(r.len() == 0) + + path, name, code := r.p.peekObj(idx) + if code != objStub { + objReader[types.NewPkg(path, "").Lookup(name)] = pkgReaderIndex{pr, idx, nil} + } + } +} + +func writeNewExport(out io.Writer) { + l := linker{ + pw: newPkgEncoder(), + + pkgs: make(map[string]int), + decls: make(map[*types.Sym]int), + } + + publicRootWriter := l.pw.newEncoder(relocMeta, syncPublic) + assert(publicRootWriter.idx == publicRootIdx) + + var selfPkgIdx int + + { + pr := localPkgReader + r := pr.newDecoder(relocMeta, publicRootIdx, syncPublic) + + r.sync(syncPkg) + selfPkgIdx = l.relocIdx(pr, relocPkg, r.reloc(relocPkg)) + + r.bool() // has init + + for i, n := 0, r.len(); i < n; i++ { + r.sync(syncObject) + assert(!r.bool()) + idx := r.reloc(relocObj) + assert(r.len() == 0) + + xpath, xname, xtag := pr.peekObj(idx) + assert(xpath == pr.pkgPath) + assert(xtag != objStub) + + if types.IsExported(xname) { + l.relocIdx(pr, relocObj, idx) + } + } + + r.sync(syncEOF) + } + + { + var idxs []int + for _, idx := range l.decls { + idxs = append(idxs, idx) + } + sort.Ints(idxs) + + w := publicRootWriter + + w.sync(syncPkg) + w.reloc(relocPkg, selfPkgIdx) + + w.bool(typecheck.Lookup(".inittask").Def != nil) + + w.len(len(idxs)) + for _, idx := range idxs { + w.sync(syncObject) + w.bool(false) + w.reloc(relocObj, idx) + w.len(0) + } + + w.sync(syncEOF) + w.flush() + } + + l.pw.dump(out) +} -- cgit v1.2.3