src

Go monorepo.
git clone git://code.dwrz.net/src
Log | Files | Refs

slicing.go (1109B)

      1 // Copyright 2021 The Go Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style
      3 // license that can be found in the LICENSE file.
      4 
      5 package vulncheck
      6 
      7 import (
      8 	"golang.org/x/tools/go/callgraph"
      9 	"golang.org/x/tools/go/ssa"
     10 )
     11 
     12 // forwardSlice computes the transitive closure of functions forward reachable
     13 // via calls in cg or referred to in an instruction starting from `sources`.
     14 func forwardSlice(sources map[*ssa.Function]bool, cg *callgraph.Graph) map[*ssa.Function]bool {
     15 	seen := make(map[*ssa.Function]bool)
     16 	var visit func(f *ssa.Function)
     17 	visit = func(f *ssa.Function) {
     18 		if seen[f] {
     19 			return
     20 		}
     21 		seen[f] = true
     22 
     23 		if n := cg.Nodes[f]; n != nil {
     24 			for _, e := range n.Out {
     25 				if e.Site != nil {
     26 					visit(e.Callee.Func)
     27 				}
     28 			}
     29 		}
     30 
     31 		var buf [10]*ssa.Value // avoid alloc in common case
     32 		for _, b := range f.Blocks {
     33 			for _, instr := range b.Instrs {
     34 				for _, op := range instr.Operands(buf[:0]) {
     35 					if fn, ok := (*op).(*ssa.Function); ok {
     36 						visit(fn)
     37 					}
     38 				}
     39 			}
     40 		}
     41 	}
     42 	for source := range sources {
     43 		visit(source)
     44 	}
     45 	return seen
     46 }