runtime: make windows goenvs look more like Go
Change-Id: I4f84a89553f77382a8064f49db0f5eb575b64313
Reviewed-on: https://go-review.googlesource.com/2714
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/runtime/os1_windows.go b/src/runtime/os1_windows.go
index 7ac1cfe..653a7b3 100644
--- a/src/runtime/os1_windows.go
+++ b/src/runtime/os1_windows.go
@@ -182,24 +182,34 @@
}
func goenvs() {
- var p *uint16
-
- env := (*uint16)(unsafe.Pointer(stdcall0(_GetEnvironmentStringsW)))
+ // strings is a pointer to environment variable pairs in the form:
+ // "envA=valA\x00envB=valB\x00\x00" (in UTF-16)
+ // Two consecutive zero bytes end the list.
+ strings := unsafe.Pointer(stdcall0(_GetEnvironmentStringsW))
+ p := (*[1 << 24]uint16)(strings)[:]
n := 0
- for p = env; *p != 0; n++ {
- p = (*uint16)(add(unsafe.Pointer(p), uintptr(findnullw(p)+1)*unsafe.Sizeof(*p)))
+ for from, i := 0, 0; true; i++ {
+ if p[i] == 0 {
+ // empty string marks the end
+ if i == from {
+ break
+ }
+ from = i + 1
+ n++
+ }
+ }
+ envs = makeStringSlice(n)
+
+ for i := range envs {
+ envs[i] = gostringw(&p[0])
+ for p[0] != 0 {
+ p = p[1:]
+ }
+ p = p[1:] // skip nil byte
}
- envs = makeStringSlice(int(n))
-
- p = env
- for i := 0; i < n; i++ {
- envs[i] = gostringw(p)
- p = (*uint16)(add(unsafe.Pointer(p), uintptr(findnullw(p)+1)*unsafe.Sizeof(*p)))
- }
-
- stdcall1(_FreeEnvironmentStringsW, uintptr(unsafe.Pointer(env)))
+ stdcall1(_FreeEnvironmentStringsW, uintptr(strings))
}
//go:nosplit
