1// Copyright 2009, 2010 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package runtime
6#include "runtime.h"
7#include "arch.h"
8#include "malloc.h"
9#include "go-string.h"
10
11#define charntorune(pv, str, len) __go_get_rune(str, len, pv)
12
13const String	runtime_emptystring;
14
15intgo
16runtime_findnull(const byte *s)
17{
18	if(s == nil)
19		return 0;
20	return __builtin_strlen((const char*) s);
21}
22
23intgo
24runtime_findnullw(const uint16 *s)
25{
26	intgo l;
27
28	if(s == nil)
29		return 0;
30	for(l=0; s[l]!=0; l++)
31		;
32	return l;
33}
34
35static String
36gostringsize(intgo l, byte** pmem)
37{
38	String s;
39	byte *mem;
40
41	if(l == 0) {
42		*pmem = nil;
43		return runtime_emptystring;
44	}
45	mem = runtime_mallocgc(l, 0, FlagNoScan|FlagNoZero);
46	s.str = mem;
47	s.len = l;
48	*pmem = mem;
49	return s;
50}
51
52String
53runtime_gostring(const byte *str)
54{
55	intgo l;
56	String s;
57	byte *mem;
58
59	l = runtime_findnull(str);
60	s = gostringsize(l, &mem);
61	runtime_memmove(mem, str, l);
62	return s;
63}
64
65String
66runtime_gostringnocopy(const byte *str)
67{
68	String s;
69
70	s.str = str;
71	s.len = runtime_findnull(str);
72	return s;
73}
74
75func cstringToGo(str *byte) (s String) {
76	s = runtime_gostringnocopy(str);
77}
78
79enum
80{
81	Runeself	= 0x80,
82};
83
84func stringiter(s String, k int) (retk int) {
85	int32 l;
86
87	if(k >= s.len) {
88		// retk=0 is end of iteration
89		retk = 0;
90		goto out;
91	}
92
93	l = s.str[k];
94	if(l < Runeself) {
95		retk = k+1;
96		goto out;
97	}
98
99	// multi-char rune
100	retk = k + charntorune(&l, s.str+k, s.len-k);
101
102out:
103}
104
105func stringiter2(s String, k int) (retk int, retv int32) {
106	if(k >= s.len) {
107		// retk=0 is end of iteration
108		retk = 0;
109		retv = 0;
110		goto out;
111	}
112
113	retv = s.str[k];
114	if(retv < Runeself) {
115		retk = k+1;
116		goto out;
117	}
118
119	// multi-char rune
120	retk = k + charntorune(&retv, s.str+k, s.len-k);
121
122out:
123}
124