mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-14 19:26:43 +00:00
131 lines
4 KiB
Go
131 lines
4 KiB
Go
// Copyright 2017 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 obj
|
|
|
|
import "github.com/twitchyliquid64/golang-asm/src"
|
|
|
|
// InlTree is a collection of inlined calls. The Parent field of an
|
|
// InlinedCall is the index of another InlinedCall in InlTree.
|
|
//
|
|
// The compiler maintains a global inlining tree and adds a node to it
|
|
// every time a function is inlined. For example, suppose f() calls g()
|
|
// and g has two calls to h(), and that f, g, and h are inlineable:
|
|
//
|
|
// 1 func main() {
|
|
// 2 f()
|
|
// 3 }
|
|
// 4 func f() {
|
|
// 5 g()
|
|
// 6 }
|
|
// 7 func g() {
|
|
// 8 h()
|
|
// 9 h()
|
|
// 10 }
|
|
// 11 func h() {
|
|
// 12 println("H")
|
|
// 13 }
|
|
//
|
|
// Assuming the global tree starts empty, inlining will produce the
|
|
// following tree:
|
|
//
|
|
// []InlinedCall{
|
|
// {Parent: -1, Func: "f", Pos: <line 2>},
|
|
// {Parent: 0, Func: "g", Pos: <line 5>},
|
|
// {Parent: 1, Func: "h", Pos: <line 8>},
|
|
// {Parent: 1, Func: "h", Pos: <line 9>},
|
|
// }
|
|
//
|
|
// The nodes of h inlined into main will have inlining indexes 2 and 3.
|
|
//
|
|
// Eventually, the compiler extracts a per-function inlining tree from
|
|
// the global inlining tree (see pcln.go).
|
|
type InlTree struct {
|
|
nodes []InlinedCall
|
|
}
|
|
|
|
// InlinedCall is a node in an InlTree.
|
|
type InlinedCall struct {
|
|
Parent int // index of the parent in the InlTree or < 0 if outermost call
|
|
Pos src.XPos // position of the inlined call
|
|
Func *LSym // function that was inlined
|
|
ParentPC int32 // PC of instruction just before inlined body. Only valid in local trees.
|
|
}
|
|
|
|
// Add adds a new call to the tree, returning its index.
|
|
func (tree *InlTree) Add(parent int, pos src.XPos, func_ *LSym) int {
|
|
r := len(tree.nodes)
|
|
call := InlinedCall{
|
|
Parent: parent,
|
|
Pos: pos,
|
|
Func: func_,
|
|
}
|
|
tree.nodes = append(tree.nodes, call)
|
|
return r
|
|
}
|
|
|
|
func (tree *InlTree) Parent(inlIndex int) int {
|
|
return tree.nodes[inlIndex].Parent
|
|
}
|
|
|
|
func (tree *InlTree) InlinedFunction(inlIndex int) *LSym {
|
|
return tree.nodes[inlIndex].Func
|
|
}
|
|
|
|
func (tree *InlTree) CallPos(inlIndex int) src.XPos {
|
|
return tree.nodes[inlIndex].Pos
|
|
}
|
|
|
|
func (tree *InlTree) setParentPC(inlIndex int, pc int32) {
|
|
tree.nodes[inlIndex].ParentPC = pc
|
|
}
|
|
|
|
// OutermostPos returns the outermost position corresponding to xpos,
|
|
// which is where xpos was ultimately inlined to. In the example for
|
|
// InlTree, main() contains inlined AST nodes from h(), but the
|
|
// outermost position for those nodes is line 2.
|
|
func (ctxt *Link) OutermostPos(xpos src.XPos) src.Pos {
|
|
pos := ctxt.InnermostPos(xpos)
|
|
|
|
outerxpos := xpos
|
|
for ix := pos.Base().InliningIndex(); ix >= 0; {
|
|
call := ctxt.InlTree.nodes[ix]
|
|
ix = call.Parent
|
|
outerxpos = call.Pos
|
|
}
|
|
return ctxt.PosTable.Pos(outerxpos)
|
|
}
|
|
|
|
// InnermostPos returns the innermost position corresponding to xpos,
|
|
// that is, the code that is inlined and that inlines nothing else.
|
|
// In the example for InlTree above, the code for println within h
|
|
// would have an innermost position with line number 12, whether
|
|
// h was not inlined, inlined into g, g-then-f, or g-then-f-then-main.
|
|
// This corresponds to what someone debugging main, f, g, or h might
|
|
// expect to see while single-stepping.
|
|
func (ctxt *Link) InnermostPos(xpos src.XPos) src.Pos {
|
|
return ctxt.PosTable.Pos(xpos)
|
|
}
|
|
|
|
// AllPos returns a slice of the positions inlined at xpos, from
|
|
// innermost (index zero) to outermost. To avoid gratuitous allocation
|
|
// the result is passed in and extended if necessary.
|
|
func (ctxt *Link) AllPos(xpos src.XPos, result []src.Pos) []src.Pos {
|
|
pos := ctxt.InnermostPos(xpos)
|
|
result = result[:0]
|
|
result = append(result, ctxt.PosTable.Pos(xpos))
|
|
for ix := pos.Base().InliningIndex(); ix >= 0; {
|
|
call := ctxt.InlTree.nodes[ix]
|
|
ix = call.Parent
|
|
result = append(result, ctxt.PosTable.Pos(call.Pos))
|
|
}
|
|
return result
|
|
}
|
|
|
|
func dumpInlTree(ctxt *Link, tree InlTree) {
|
|
for i, call := range tree.nodes {
|
|
pos := ctxt.PosTable.Pos(call.Pos)
|
|
ctxt.Logf("%0d | %0d | %s (%s) pc=%d\n", i, call.Parent, call.Func, pos, call.ParentPC)
|
|
}
|
|
}
|