github.com/powerman/golang-tools@v0.1.11-0.20220410185822-5ad214d8d803/go/callgraph/static/static.go (about)

     1  // Copyright 2014 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 static computes the call graph of a Go program containing
     6  // only static call edges.
     7  package static // import "github.com/powerman/golang-tools/go/callgraph/static"
     8  
     9  import (
    10  	"github.com/powerman/golang-tools/go/callgraph"
    11  	"github.com/powerman/golang-tools/go/ssa"
    12  	"github.com/powerman/golang-tools/go/ssa/ssautil"
    13  )
    14  
    15  // CallGraph computes the call graph of the specified program
    16  // considering only static calls.
    17  //
    18  func CallGraph(prog *ssa.Program) *callgraph.Graph {
    19  	cg := callgraph.New(nil) // TODO(adonovan) eliminate concept of rooted callgraph
    20  
    21  	// TODO(adonovan): opt: use only a single pass over the ssa.Program.
    22  	// TODO(adonovan): opt: this is slower than RTA (perhaps because
    23  	// the lower precision means so many edges are allocated)!
    24  	for f := range ssautil.AllFunctions(prog) {
    25  		fnode := cg.CreateNode(f)
    26  		for _, b := range f.Blocks {
    27  			for _, instr := range b.Instrs {
    28  				if site, ok := instr.(ssa.CallInstruction); ok {
    29  					if g := site.Common().StaticCallee(); g != nil {
    30  						gnode := cg.CreateNode(g)
    31  						callgraph.AddEdge(fnode, site, gnode)
    32  					}
    33  				}
    34  			}
    35  		}
    36  	}
    37  
    38  	return cg
    39  }