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// Copyright 2013 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 pointer
// This file defines the internal (context-sensitive) call graph.
import (
"fmt"
"go/token"
"golang.org/x/tools/go/ssa"
)
type cgnode struct {
fn *ssa.Function
obj nodeid // start of this contour's object block
sites []*callsite // ordered list of callsites within this function
callersite *callsite // where called from, if known; nil for shared contours
}
// contour returns a description of this node's contour.
func (n *cgnode) contour() string {
if n.callersite == nil {
return "shared contour"
}
if n.callersite.instr != nil {
return fmt.Sprintf("as called from %s", n.callersite.instr.Parent())
}
return fmt.Sprintf("as called from intrinsic (targets=n%d)", n.callersite.targets)
}
func (n *cgnode) String() string {
return fmt.Sprintf("cg%d:%s", n.obj, n.fn)
}
// A callsite represents a single call site within a cgnode;
// it is implicitly context-sensitive.
// callsites never represent calls to built-ins;
// they are handled as intrinsics.
type callsite struct {
targets nodeid // pts(ยท) contains objects for dynamically called functions
instr ssa.CallInstruction // the call instruction; nil for synthetic/intrinsic
}
func (c *callsite) String() string {
if c.instr != nil {
return c.instr.Common().Description()
}
return "synthetic function call"
}
// pos returns the source position of this callsite, or token.NoPos if implicit.
func (c *callsite) pos() token.Pos {
if c.instr != nil {
return c.instr.Pos()
}
return token.NoPos
}