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// 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/syntax"
"cmd/internal/obj"
"cmd/internal/src"
"fmt"
"strings"
)
// lineno is the source position at the start of the most recently lexed token.
// TODO(gri) rename and eventually remove
var lineno src.XPos
func MakePos(base *src.PosBase, line, col uint) src.XPos {
return Ctxt.PosTable.XPos(src.MakePos(base, line, col))
}
func isSpace(c rune) bool {
return c == ' ' || c == '\t' || c == '\n' || c == '\r'
}
func isQuoted(s string) bool {
return len(s) >= 2 && s[0] == '"' && s[len(s)-1] == '"'
}
func plan9quote(s string) string {
if s == "" {
return "''"
}
for _, c := range s {
if c <= ' ' || c == '\'' {
return "'" + strings.Replace(s, "'", "''", -1) + "'"
}
}
return s
}
const (
// Func pragmas.
Nointerface syntax.Pragma = 1 << iota
Noescape // func parameters don't escape
Norace // func must not have race detector annotations
Nosplit // func should not execute on separate stack
Noinline // func should not be inlined
CgoUnsafeArgs // treat a pointer to one arg as a pointer to them all
UintptrEscapes // pointers converted to uintptr escape
// Runtime-only func pragmas.
// See ../../../../runtime/README.md for detailed descriptions.
Systemstack // func must run on system stack
Nowritebarrier // emit compiler error instead of write barrier
Nowritebarrierrec // error on write barrier in this or recursive callees
Yeswritebarrierrec // cancels Nowritebarrierrec in this function and callees
// Runtime-only type pragmas
NotInHeap // values of this type must not be heap allocated
)
func pragmaValue(verb string) syntax.Pragma {
switch verb {
case "go:nointerface":
if obj.Fieldtrack_enabled != 0 {
return Nointerface
}
case "go:noescape":
return Noescape
case "go:norace":
return Norace
case "go:nosplit":
return Nosplit
case "go:noinline":
return Noinline
case "go:systemstack":
return Systemstack
case "go:nowritebarrier":
return Nowritebarrier
case "go:nowritebarrierrec":
return Nowritebarrierrec | Nowritebarrier // implies Nowritebarrier
case "go:yeswritebarrierrec":
return Yeswritebarrierrec
case "go:cgo_unsafe_args":
return CgoUnsafeArgs
case "go:uintptrescapes":
// For the next function declared in the file
// any uintptr arguments may be pointer values
// converted to uintptr. This directive
// ensures that the referenced allocated
// object, if any, is retained and not moved
// until the call completes, even though from
// the types alone it would appear that the
// object is no longer needed during the
// call. The conversion to uintptr must appear
// in the argument list.
// Used in syscall/dll_windows.go.
return UintptrEscapes
case "go:notinheap":
return NotInHeap
}
return 0
}
var internedStrings = map[string]string{}
func internString(b []byte) string {
s, ok := internedStrings[string(b)] // string(b) here doesn't allocate
if !ok {
s = string(b)
internedStrings[s] = s
}
return s
}
func pragcgo(text string) string {
f := pragmaFields(text)
verb := f[0][3:] // skip "go:"
switch verb {
case "cgo_export_static", "cgo_export_dynamic":
switch {
case len(f) == 2 && !isQuoted(f[1]):
local := plan9quote(f[1])
return fmt.Sprintln(verb, local)
case len(f) == 3 && !isQuoted(f[1]) && !isQuoted(f[2]):
local := plan9quote(f[1])
remote := plan9quote(f[2])
return fmt.Sprintln(verb, local, remote)
default:
yyerror(`usage: //go:%s local [remote]`, verb)
}
case "cgo_import_dynamic":
switch {
case len(f) == 2 && !isQuoted(f[1]):
local := plan9quote(f[1])
return fmt.Sprintln(verb, local)
case len(f) == 3 && !isQuoted(f[1]) && !isQuoted(f[2]):
local := plan9quote(f[1])
remote := plan9quote(f[2])
return fmt.Sprintln(verb, local, remote)
case len(f) == 4 && !isQuoted(f[1]) && !isQuoted(f[2]) && isQuoted(f[3]):
local := plan9quote(f[1])
remote := plan9quote(f[2])
library := plan9quote(strings.Trim(f[3], `"`))
return fmt.Sprintln(verb, local, remote, library)
default:
yyerror(`usage: //go:cgo_import_dynamic local [remote ["library"]]`)
}
case "cgo_import_static":
switch {
case len(f) == 2 && !isQuoted(f[1]):
local := plan9quote(f[1])
return fmt.Sprintln(verb, local)
default:
yyerror(`usage: //go:cgo_import_static local`)
}
case "cgo_dynamic_linker":
switch {
case len(f) == 2 && isQuoted(f[1]):
path := plan9quote(strings.Trim(f[1], `"`))
return fmt.Sprintln(verb, path)
default:
yyerror(`usage: //go:cgo_dynamic_linker "path"`)
}
case "cgo_ldflag":
switch {
case len(f) == 2 && isQuoted(f[1]):
arg := plan9quote(strings.Trim(f[1], `"`))
return fmt.Sprintln(verb, arg)
default:
yyerror(`usage: //go:cgo_ldflag "arg"`)
}
}
return ""
}
// pragmaFields is similar to strings.FieldsFunc(s, isSpace)
// but does not split when inside double quoted regions and always
// splits before the start and after the end of a double quoted region.
// pragmaFields does not recognize escaped quotes. If a quote in s is not
// closed the part after the opening quote will not be returned as a field.
func pragmaFields(s string) []string {
var a []string
inQuote := false
fieldStart := -1 // Set to -1 when looking for start of field.
for i, c := range s {
switch {
case c == '"':
if inQuote {
inQuote = false
a = append(a, s[fieldStart:i+1])
fieldStart = -1
} else {
inQuote = true
if fieldStart >= 0 {
a = append(a, s[fieldStart:i])
}
fieldStart = i
}
case !inQuote && isSpace(c):
if fieldStart >= 0 {
a = append(a, s[fieldStart:i])
fieldStart = -1
}
default:
if fieldStart == -1 {
fieldStart = i
}
}
}
if !inQuote && fieldStart >= 0 { // Last field might end at the end of the string.
a = append(a, s[fieldStart:])
}
return a
}
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