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authorRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
committerRuss Cox <rsc@golang.org>2014-09-08 00:08:51 -0400
commitc007ce824d9a4fccb148f9204e04c23ed2984b71 (patch)
tree7dcac257114ef5c446be5b7b68c27dea230b7c09 /src/runtime/string.c
parent220a6de47eced55956eb8af8d643d4f5b67fd634 (diff)
downloadgo-c007ce824d9a4fccb148f9204e04c23ed2984b71.tar.xz
build: move package sources from src/pkg to src
Preparation was in CL 134570043. This CL contains only the effect of 'hg mv src/pkg/* src'. For more about the move, see golang.org/s/go14nopkg.
Diffstat (limited to 'src/runtime/string.c')
-rw-r--r--src/runtime/string.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/src/runtime/string.c b/src/runtime/string.c
new file mode 100644
index 0000000000..4f25adf8e3
--- /dev/null
+++ b/src/runtime/string.c
@@ -0,0 +1,288 @@
+// 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.
+
+#include "runtime.h"
+#include "arch_GOARCH.h"
+#include "malloc.h"
+#include "race.h"
+#include "textflag.h"
+
+String runtime·emptystring;
+
+#pragma textflag NOSPLIT
+intgo
+runtime·findnull(byte *s)
+{
+ intgo l;
+
+ if(s == nil)
+ return 0;
+ for(l=0; s[l]!=0; l++)
+ ;
+ return l;
+}
+
+intgo
+runtime·findnullw(uint16 *s)
+{
+ intgo l;
+
+ if(s == nil)
+ return 0;
+ for(l=0; s[l]!=0; l++)
+ ;
+ return l;
+}
+
+uintptr runtime·maxstring = 256; // a hint for print
+
+static String
+gostringsize(intgo l)
+{
+ String s;
+ uintptr ms;
+
+ if(l == 0)
+ return runtime·emptystring;
+ s.str = runtime·mallocgc(l, 0, FlagNoScan|FlagNoZero);
+ s.len = l;
+ for(;;) {
+ ms = runtime·maxstring;
+ if((uintptr)l <= ms || runtime·casp((void**)&runtime·maxstring, (void*)ms, (void*)l))
+ break;
+ }
+ return s;
+}
+
+String
+runtime·gostring(byte *str)
+{
+ intgo l;
+ String s;
+
+ l = runtime·findnull(str);
+ s = gostringsize(l);
+ runtime·memmove(s.str, str, l);
+ return s;
+}
+
+String
+runtime·gostringn(byte *str, intgo l)
+{
+ String s;
+
+ s = gostringsize(l);
+ runtime·memmove(s.str, str, l);
+ return s;
+}
+
+// used by cmd/cgo
+Slice
+runtime·gobytes(byte *p, intgo n)
+{
+ Slice sl;
+
+ sl.array = runtime·mallocgc(n, 0, FlagNoScan|FlagNoZero);
+ sl.len = n;
+ sl.cap = n;
+ runtime·memmove(sl.array, p, n);
+ return sl;
+}
+
+#pragma textflag NOSPLIT
+String
+runtime·gostringnocopy(byte *str)
+{
+ String s;
+
+ s.str = str;
+ s.len = runtime·findnull(str);
+ return s;
+}
+
+// TODO: move this elsewhere
+enum
+{
+ Bit1 = 7,
+ Bitx = 6,
+ Bit2 = 5,
+ Bit3 = 4,
+ Bit4 = 3,
+ Bit5 = 2,
+
+ Tx = ((1<<(Bitx+1))-1) ^ 0xFF, /* 1000 0000 */
+ T2 = ((1<<(Bit2+1))-1) ^ 0xFF, /* 1100 0000 */
+ T3 = ((1<<(Bit3+1))-1) ^ 0xFF, /* 1110 0000 */
+ T4 = ((1<<(Bit4+1))-1) ^ 0xFF, /* 1111 0000 */
+
+ Rune1 = (1<<(Bit1+0*Bitx))-1, /* 0000 0000 0111 1111 */
+ Rune2 = (1<<(Bit2+1*Bitx))-1, /* 0000 0111 1111 1111 */
+ Rune3 = (1<<(Bit3+2*Bitx))-1, /* 1111 1111 1111 1111 */
+
+ Maskx = (1<<Bitx)-1, /* 0011 1111 */
+
+ Runeerror = 0xFFFD,
+
+ SurrogateMin = 0xD800,
+ SurrogateMax = 0xDFFF,
+
+ Runemax = 0x10FFFF, /* maximum rune value */
+};
+
+static int32
+runetochar(byte *str, int32 rune) /* note: in original, arg2 was pointer */
+{
+ /* Runes are signed, so convert to unsigned for range check. */
+ uint32 c;
+
+ /*
+ * one character sequence
+ * 00000-0007F => 00-7F
+ */
+ c = rune;
+ if(c <= Rune1) {
+ str[0] = c;
+ return 1;
+ }
+
+ /*
+ * two character sequence
+ * 0080-07FF => T2 Tx
+ */
+ if(c <= Rune2) {
+ str[0] = T2 | (c >> 1*Bitx);
+ str[1] = Tx | (c & Maskx);
+ return 2;
+ }
+
+ /*
+ * If the Rune is out of range or a surrogate half, convert it to the error rune.
+ * Do this test here because the error rune encodes to three bytes.
+ * Doing it earlier would duplicate work, since an out of range
+ * Rune wouldn't have fit in one or two bytes.
+ */
+ if (c > Runemax)
+ c = Runeerror;
+ if (SurrogateMin <= c && c <= SurrogateMax)
+ c = Runeerror;
+
+ /*
+ * three character sequence
+ * 0800-FFFF => T3 Tx Tx
+ */
+ if (c <= Rune3) {
+ str[0] = T3 | (c >> 2*Bitx);
+ str[1] = Tx | ((c >> 1*Bitx) & Maskx);
+ str[2] = Tx | (c & Maskx);
+ return 3;
+ }
+
+ /*
+ * four character sequence (21-bit value)
+ * 10000-1FFFFF => T4 Tx Tx Tx
+ */
+ str[0] = T4 | (c >> 3*Bitx);
+ str[1] = Tx | ((c >> 2*Bitx) & Maskx);
+ str[2] = Tx | ((c >> 1*Bitx) & Maskx);
+ str[3] = Tx | (c & Maskx);
+ return 4;
+}
+
+String
+runtime·gostringw(uint16 *str)
+{
+ intgo n1, n2, i;
+ byte buf[8];
+ String s;
+
+ n1 = 0;
+ for(i=0; str[i]; i++)
+ n1 += runetochar(buf, str[i]);
+ s = gostringsize(n1+4);
+ n2 = 0;
+ for(i=0; str[i]; i++) {
+ // check for race
+ if(n2 >= n1)
+ break;
+ n2 += runetochar(s.str+n2, str[i]);
+ }
+ s.len = n2;
+ s.str[s.len] = 0;
+ return s;
+}
+
+String
+runtime·catstring(String s1, String s2)
+{
+ String s3;
+
+ if(s1.len == 0)
+ return s2;
+ if(s2.len == 0)
+ return s1;
+
+ s3 = gostringsize(s1.len + s2.len);
+ runtime·memmove(s3.str, s1.str, s1.len);
+ runtime·memmove(s3.str+s1.len, s2.str, s2.len);
+ return s3;
+}
+
+int32
+runtime·strcmp(byte *s1, byte *s2)
+{
+ uintptr i;
+ byte c1, c2;
+
+ for(i=0;; i++) {
+ c1 = s1[i];
+ c2 = s2[i];
+ if(c1 < c2)
+ return -1;
+ if(c1 > c2)
+ return +1;
+ if(c1 == 0)
+ return 0;
+ }
+}
+
+int32
+runtime·strncmp(byte *s1, byte *s2, uintptr n)
+{
+ uintptr i;
+ byte c1, c2;
+
+ for(i=0; i<n; i++) {
+ c1 = s1[i];
+ c2 = s2[i];
+ if(c1 < c2)
+ return -1;
+ if(c1 > c2)
+ return +1;
+ if(c1 == 0)
+ break;
+ }
+ return 0;
+}
+
+byte*
+runtime·strstr(byte *s1, byte *s2)
+{
+ byte *sp1, *sp2;
+
+ if(*s2 == 0)
+ return s1;
+ for(; *s1; s1++) {
+ if(*s1 != *s2)
+ continue;
+ sp1 = s1;
+ sp2 = s2;
+ for(;;) {
+ if(*sp2 == 0)
+ return s1;
+ if(*sp1++ != *sp2++)
+ break;
+ }
+ }
+ return nil;
+}