[dev.cc] runtime: convert memory allocator and garbage collector to Go

The conversion was done with an automated tool and then
modified only as necessary to make it compile and run.

[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]

LGTM=r
R=r
CC=austin, dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/167540043

1 files changed, 10 insertions, 4 deletions

diff --git a/src/runtime/string.go b/src/runtime/string.go
index 0809f89bc1..0845c94e24 100644
--- a/src/runtime/string.go
+++ b/src/runtime/string.go
@@ -225,7 +225,7 @@ func rawbyteslice(size int) (b []byte) {
 
 // rawruneslice allocates a new rune slice. The rune slice is not zeroed.
 func rawruneslice(size int) (b []rune) {
-	if uintptr(size) > maxmem/4 {
+	if uintptr(size) > _MaxMem/4 {
 		gothrow("out of memory")
 	}
 	mem := goroundupsize(uintptr(size) * 4)
@@ -255,9 +255,6 @@ func gostringsize(n int) string {
 	return s
 }
 
-//go:noescape
-func findnull(*byte) int
-
 func gostring(p *byte) string {
 	l := findnull(p)
 	if l == 0 {
@@ -296,3 +293,12 @@ func contains(s, t string) bool {
 func hasprefix(s, t string) bool {
 	return len(s) >= len(t) && s[:len(t)] == t
 }
+
+func goatoi(s string) int {
+	n := 0
+	for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
+		n = n*10 + int(s[0]) - '0'
+		s = s[1:]
+	}
+	return n
+}