116 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			Go
		
	
	
	
			
		
		
	
	
			116 lines
		
	
	
		
			2.8 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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| 
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| package oracle
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| 
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| import (
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| 	"fmt"
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| 	"go/token"
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| 
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| 	"golang.org/x/tools/go/callgraph"
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| 	"golang.org/x/tools/go/loader"
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| 	"golang.org/x/tools/go/ssa"
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| 	"golang.org/x/tools/go/ssa/ssautil"
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| 	"golang.org/x/tools/oracle/serial"
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| )
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| 
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| // Callers reports the possible callers of the function
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| // immediately enclosing the specified source location.
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| //
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| func callers(q *Query) error {
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| 	lconf := loader.Config{Build: q.Build}
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| 
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| 	if err := setPTAScope(&lconf, q.Scope); err != nil {
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| 		return err
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| 	}
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| 
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| 	// Load/parse/type-check the program.
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| 	lprog, err := lconf.Load()
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| 	if err != nil {
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| 		return err
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| 	}
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| 	q.Fset = lprog.Fset
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| 
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| 	qpos, err := parseQueryPos(lprog, q.Pos, false)
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| 	if err != nil {
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| 		return err
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| 	}
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| 
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| 	prog := ssautil.CreateProgram(lprog, 0)
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| 
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| 	ptaConfig, err := setupPTA(prog, lprog, q.PTALog, q.Reflection)
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| 	if err != nil {
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| 		return err
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| 	}
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| 
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| 	pkg := prog.Package(qpos.info.Pkg)
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| 	if pkg == nil {
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| 		return fmt.Errorf("no SSA package")
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| 	}
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| 	if !ssa.HasEnclosingFunction(pkg, qpos.path) {
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| 		return fmt.Errorf("this position is not inside a function")
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| 	}
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| 
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| 	// Defer SSA construction till after errors are reported.
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| 	prog.BuildAll()
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| 
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| 	target := ssa.EnclosingFunction(pkg, qpos.path)
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| 	if target == nil {
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| 		return fmt.Errorf("no SSA function built for this location (dead code?)")
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| 	}
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| 
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| 	// TODO(adonovan): opt: if function is never address-taken, skip
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| 	// the pointer analysis.  Just look for direct calls.  This can
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| 	// be done in a single pass over the SSA.
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| 
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| 	// Run the pointer analysis, recording each
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| 	// call found to originate from target.
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| 	ptaConfig.BuildCallGraph = true
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| 	cg := ptrAnalysis(ptaConfig).CallGraph
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| 	cg.DeleteSyntheticNodes()
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| 	edges := cg.CreateNode(target).In
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| 	// TODO(adonovan): sort + dedup calls to ensure test determinism.
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| 
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| 	q.result = &callersResult{
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| 		target:    target,
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| 		callgraph: cg,
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| 		edges:     edges,
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| 	}
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| 	return nil
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| }
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| 
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| type callersResult struct {
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| 	target    *ssa.Function
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| 	callgraph *callgraph.Graph
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| 	edges     []*callgraph.Edge
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| }
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| 
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| func (r *callersResult) display(printf printfFunc) {
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| 	root := r.callgraph.Root
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| 	if r.edges == nil {
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| 		printf(r.target, "%s is not reachable in this program.", r.target)
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| 	} else {
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| 		printf(r.target, "%s is called from these %d sites:", r.target, len(r.edges))
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| 		for _, edge := range r.edges {
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| 			if edge.Caller == root {
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| 				printf(r.target, "the root of the call graph")
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| 			} else {
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| 				printf(edge, "\t%s from %s", edge.Description(), edge.Caller.Func)
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| 			}
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| 		}
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| 	}
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| }
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| 
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| func (r *callersResult) toSerial(res *serial.Result, fset *token.FileSet) {
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| 	var callers []serial.Caller
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| 	for _, edge := range r.edges {
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| 		callers = append(callers, serial.Caller{
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| 			Caller: edge.Caller.Func.String(),
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| 			Pos:    fset.Position(edge.Pos()).String(),
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| 			Desc:   edge.Description(),
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| 		})
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| 	}
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| 	res.Callers = callers
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| }
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