79 lines
2 KiB
Go
79 lines
2 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package irutil // import "honnef.co/go/tools/ir/irutil"
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import "honnef.co/go/tools/ir"
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// This file defines utilities for visiting the IR of
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// a Program.
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//
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// TODO(adonovan): test coverage.
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// AllFunctions finds and returns the set of functions potentially
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// needed by program prog, as determined by a simple linker-style
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// reachability algorithm starting from the members and method-sets of
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// each package. The result may include anonymous functions and
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// synthetic wrappers.
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//
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// Precondition: all packages are built.
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//
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func AllFunctions(prog *ir.Program) map[*ir.Function]bool {
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visit := visitor{
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prog: prog,
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seen: make(map[*ir.Function]bool),
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}
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visit.program()
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return visit.seen
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}
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type visitor struct {
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prog *ir.Program
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seen map[*ir.Function]bool
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}
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func (visit *visitor) program() {
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for _, pkg := range visit.prog.AllPackages() {
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for _, mem := range pkg.Members {
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if fn, ok := mem.(*ir.Function); ok {
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visit.function(fn)
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}
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}
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}
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for _, T := range visit.prog.RuntimeTypes() {
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mset := visit.prog.MethodSets.MethodSet(T)
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for i, n := 0, mset.Len(); i < n; i++ {
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visit.function(visit.prog.MethodValue(mset.At(i)))
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}
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}
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}
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func (visit *visitor) function(fn *ir.Function) {
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if !visit.seen[fn] {
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visit.seen[fn] = true
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var buf [10]*ir.Value // avoid alloc in common case
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for _, b := range fn.Blocks {
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for _, instr := range b.Instrs {
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for _, op := range instr.Operands(buf[:0]) {
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if fn, ok := (*op).(*ir.Function); ok {
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visit.function(fn)
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}
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}
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}
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}
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}
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}
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// MainPackages returns the subset of the specified packages
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// named "main" that define a main function.
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// The result may include synthetic "testmain" packages.
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func MainPackages(pkgs []*ir.Package) []*ir.Package {
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var mains []*ir.Package
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for _, pkg := range pkgs {
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if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil {
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mains = append(mains, pkg)
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}
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}
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return mains
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}
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