1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
// Copyright 2009 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 gc
import (
"cmd/compile/internal/base"
"cmd/compile/internal/ir"
"cmd/compile/internal/types"
"cmd/internal/obj"
)
// A function named init is a special case.
// It is called by the initialization before main is run.
// To make it unique within a package and also uncallable,
// the name, normally "pkg.init", is altered to "pkg.init.0".
var renameinitgen int
// Function collecting autotmps generated during typechecking,
// to be included in the package-level init function.
var initTodo = ir.Nod(ir.ODCLFUNC, nil, nil)
func renameinit() *types.Sym {
s := lookupN("init.", renameinitgen)
renameinitgen++
return s
}
// fninit makes an initialization record for the package.
// See runtime/proc.go:initTask for its layout.
// The 3 tasks for initialization are:
// 1) Initialize all of the packages the current package depends on.
// 2) Initialize all the variables that have initializers.
// 3) Run any init functions.
func fninit(n []ir.Node) {
nf := initOrder(n)
var deps []*obj.LSym // initTask records for packages the current package depends on
var fns []*obj.LSym // functions to call for package initialization
// Find imported packages with init tasks.
for _, s := range types.InitSyms {
deps = append(deps, s.Linksym())
}
// Make a function that contains all the initialization statements.
if len(nf) > 0 {
base.Pos = nf[0].Pos() // prolog/epilog gets line number of first init stmt
initializers := lookup("init")
fn := dclfunc(initializers, ir.Nod(ir.OTFUNC, nil, nil))
for _, dcl := range initTodo.Func().Dcl {
dcl.Name().Curfn = fn
}
fn.Func().Dcl = append(fn.Func().Dcl, initTodo.Func().Dcl...)
initTodo.Func().Dcl = nil
fn.PtrBody().Set(nf)
funcbody()
fn = typecheck(fn, ctxStmt)
Curfn = fn
typecheckslice(nf, ctxStmt)
Curfn = nil
xtop = append(xtop, fn)
fns = append(fns, initializers.Linksym())
}
if initTodo.Func().Dcl != nil {
// We only generate temps using initTodo if there
// are package-scope initialization statements, so
// something's weird if we get here.
base.Fatalf("initTodo still has declarations")
}
initTodo = nil
// Record user init functions.
for i := 0; i < renameinitgen; i++ {
s := lookupN("init.", i)
fn := ir.AsNode(s.Def).Name().Defn
// Skip init functions with empty bodies.
if fn.Body().Len() == 1 && fn.Body().First().Op() == ir.OEMPTY {
continue
}
fns = append(fns, s.Linksym())
}
if len(deps) == 0 && len(fns) == 0 && ir.LocalPkg.Name != "main" && ir.LocalPkg.Name != "runtime" {
return // nothing to initialize
}
// Make an .inittask structure.
sym := lookup(".inittask")
nn := NewName(sym)
nn.SetType(types.Types[types.TUINT8]) // fake type
nn.SetClass(ir.PEXTERN)
sym.Def = nn
exportsym(nn)
lsym := sym.Linksym()
ot := 0
ot = duintptr(lsym, ot, 0) // state: not initialized yet
ot = duintptr(lsym, ot, uint64(len(deps)))
ot = duintptr(lsym, ot, uint64(len(fns)))
for _, d := range deps {
ot = dsymptr(lsym, ot, d, 0)
}
for _, f := range fns {
ot = dsymptr(lsym, ot, f, 0)
}
// An initTask has pointers, but none into the Go heap.
// It's not quite read only, the state field must be modifiable.
ggloblsym(lsym, int32(ot), obj.NOPTR)
}
|
