syscall: another attempt to keep windows syscall pointers live
This approach was suggested in
https://golang.org/cl/138250043/#msg15.
Unlike current version of mksyscall_windows.go,
new code could be used in go.sys and other external
repos without help from asm.
LGTM=iant
R=golang-codereviews, iant, r
CC=golang-codereviews
https://golang.org/cl/143160046
diff --git a/src/syscall/mksyscall_windows.go b/src/syscall/mksyscall_windows.go
index 1cdd6b4..316e88d 100644
--- a/src/syscall/mksyscall_windows.go
+++ b/src/syscall/mksyscall_windows.go
@@ -138,8 +138,6 @@
// TmpVarCode returns source code for temp variable.
func (p *Param) TmpVarCode() string {
switch {
- case p.Type == "string":
- return p.StringTmpVarCode()
case p.Type == "bool":
return p.BoolTmpVarCode()
case strings.HasPrefix(p.Type, "[]"):
@@ -149,19 +147,26 @@
}
}
+// TmpVarHelperCode returns source code for helper's temp variable.
+func (p *Param) TmpVarHelperCode() string {
+ if p.Type != "string" {
+ return ""
+ }
+ return p.StringTmpVarCode()
+}
+
// SyscallArgList returns source code fragments representing p parameter
// in syscall. Slices are translated into 2 syscall parameters: pointer to
// the first element and length.
func (p *Param) SyscallArgList() []string {
+ t := p.HelperType()
var s string
switch {
- case p.Type[0] == '*':
+ case t[0] == '*':
s = fmt.Sprintf("unsafe.Pointer(%s)", p.Name)
- case p.Type == "string":
- s = fmt.Sprintf("unsafe.Pointer(%s)", p.tmpVar())
- case p.Type == "bool":
+ case t == "bool":
s = p.tmpVar()
- case strings.HasPrefix(p.Type, "[]"):
+ case strings.HasPrefix(t, "[]"):
return []string{
fmt.Sprintf("uintptr(unsafe.Pointer(%s))", p.tmpVar()),
fmt.Sprintf("uintptr(len(%s))", p.Name),
@@ -177,6 +182,14 @@
return p.Name == "err" && p.Type == "error"
}
+// HelperType returns type of parameter p used in helper function.
+func (p *Param) HelperType() string {
+ if p.Type == "string" {
+ return p.fn.StrconvType()
+ }
+ return p.Type
+}
+
// join concatenates parameters ps into a string with sep separator.
// Each parameter is converted into string by applying fn to it
// before conversion.
@@ -454,6 +467,11 @@
return join(f.Params, func(p *Param) string { return p.Name + " " + p.Type }, ", ")
}
+// HelperParamList returns source code for helper function f parameters.
+func (f *Fn) HelperParamList() string {
+ return join(f.Params, func(p *Param) string { return p.Name + " " + p.HelperType() }, ", ")
+}
+
// ParamPrintList returns source code of trace printing part correspondent
// to syscall input parameters.
func (f *Fn) ParamPrintList() string {
@@ -510,6 +528,19 @@
return strings.Join(a, ", ")
}
+// HelperCallParamList returns source code of call into function f helper.
+func (f *Fn) HelperCallParamList() string {
+ a := make([]string, 0, len(f.Params))
+ for _, p := range f.Params {
+ s := p.Name
+ if p.Type == "string" {
+ s = p.tmpVar()
+ }
+ a = append(a, s)
+ }
+ return strings.Join(a, ", ")
+}
+
// IsUTF16 is true, if f is W (utf16) function. It is false
// for all A (ascii) functions.
func (f *Fn) IsUTF16() bool {
@@ -533,6 +564,25 @@
return "*byte"
}
+// HasStringParam is true, if f has at least one string parameter.
+// Otherwise it is false.
+func (f *Fn) HasStringParam() bool {
+ for _, p := range f.Params {
+ if p.Type == "string" {
+ return true
+ }
+ }
+ return false
+}
+
+// HelperName returns name of function f helper.
+func (f *Fn) HelperName() string {
+ if !f.HasStringParam() {
+ return f.Name
+ }
+ return "_" + f.Name
+}
+
// Source files and functions.
type Source struct {
Funcs []*Fn
@@ -666,7 +716,7 @@
var (
{{template "dlls" .}}
{{template "funcnames" .}})
-{{range .Funcs}}{{template "funcbody" .}}{{end}}
+{{range .Funcs}}{{if .HasStringParam}}{{template "helperbody" .}}{{end}}{{template "funcbody" .}}{{end}}
{{end}}
{{/* help functions */}}
@@ -677,16 +727,27 @@
{{define "funcnames"}}{{range .Funcs}} proc{{.DLLFuncName}} = mod{{.DLLName}}.NewProc("{{.DLLFuncName}}")
{{end}}{{end}}
+{{define "helperbody"}}
+func {{.Name}}({{.ParamList}}) {{template "results" .}}{
+{{template "helpertmpvars" .}} return {{.HelperName}}({{.HelperCallParamList}})
+}
+{{end}}
+
{{define "funcbody"}}
-func {{.Name}}({{.ParamList}}) {{if .Rets.List}}{{.Rets.List}} {{end}}{
+func {{.HelperName}}({{.HelperParamList}}) {{template "results" .}}{
{{template "tmpvars" .}} {{template "syscall" .}}
{{template "seterror" .}}{{template "printtrace" .}} return
}
{{end}}
+{{define "helpertmpvars"}}{{range .Params}}{{if .TmpVarHelperCode}} {{.TmpVarHelperCode}}
+{{end}}{{end}}{{end}}
+
{{define "tmpvars"}}{{range .Params}}{{if .TmpVarCode}} {{.TmpVarCode}}
{{end}}{{end}}{{end}}
+{{define "results"}}{{if .Rets.List}}{{.Rets.List}} {{end}}{{end}}
+
{{define "syscall"}}{{.Rets.SetReturnValuesCode}}{{.Syscall}}(proc{{.DLLFuncName}}.Addr(), {{.ParamCount}}, {{.SyscallParamList}}){{end}}
{{define "seterror"}}{{if .Rets.SetErrorCode}} {{.Rets.SetErrorCode}}
