| // 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 |
| } |