Mercurial > ecos-v2_0-branch

comparison packages/language/c/libc/string/current/src/strlen.cxx @ 115:6ed91473a1cd ecos-sw-2000-08-21

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Merge from eCos master repository on 2000-08-21-22:40:54-BST
author jlarmour
date Fri, 25 Aug 2000 17:32:38 +0000
parents
children e0c0827131d1
comparison
equal deleted inserted replaced
114:5ad2b71d525e 115:6ed91473a1cd
1 //===========================================================================
2 //
3 // strlen.cxx
4 //
5 // ANSI standard strlen() routine
6 //
7 //===========================================================================
8 //####COPYRIGHTBEGIN####
9 //
10 // -------------------------------------------
11 // The contents of this file are subject to the Red Hat eCos Public License
12 // Version 1.1 (the "License"); you may not use this file except in
13 // compliance with the License. You may obtain a copy of the License at
14 // http://www.redhat.com/
15 //
16 // Software distributed under the License is distributed on an "AS IS"
17 // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
18 // License for the specific language governing rights and limitations under
19 // the License.
20 //
21 // The Original Code is eCos - Embedded Configurable Operating System,
22 // released September 30, 1998.
23 //
24 // The Initial Developer of the Original Code is Red Hat.
25 // Portions created by Red Hat are
26 // Copyright (C) 1998, 1999, 2000 Red Hat, Inc.
27 // All Rights Reserved.
28 // -------------------------------------------
29 //
30 //####COPYRIGHTEND####
31 //===========================================================================
32 //#####DESCRIPTIONBEGIN####
33 //
34 // Author(s): jlarmour
35 // Contributors:
36 // Date: 2000-04-14
37 // Purpose:
38 // Description:
39 // Usage:
40 //
41 //####DESCRIPTIONEND####
42 //
43 //===========================================================================
44
45 // CONFIGURATION
46
47 #include <pkgconf/libc_string.h> // Configuration header
48
49 // INCLUDES
50
51 #include <cyg/infra/cyg_type.h> // Common type definitions
52 #include <cyg/infra/cyg_trac.h> // Tracing support
53 #include <cyg/infra/cyg_ass.h> // Assertion support
54 #include <string.h> // Header for this file
55 #include <stddef.h> // Compiler definitions such as size_t, NULL etc.
56 #include <cyg/libc/string/stringsupp.hxx> // Useful string function support and
57 // prototypes
58
59 // EXPORTED SYMBOLS
60
61 externC size_t
62 strlen( const char *s ) CYGBLD_ATTRIB_WEAK_ALIAS(__strlen);
63
64 // FUNCTIONS
65
66 size_t
67 __strlen( const char *s )
68 {
69 int retval;
70
71 CYG_REPORT_FUNCNAMETYPE( "__strlen", "returning length %d" );
72 CYG_REPORT_FUNCARG1( "s=%08x", s );
73
74 CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" );
75
76 #if defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) || defined(__OPTIMIZE_SIZE__)
77 const char *start = s;
78
79 while (*s)
80 s++;
81
82 retval = s - start;
83
84 CYG_REPORT_RETVAL( retval );
85
86 return retval;
87
88 #else
89
90 const char *start = s;
91 CYG_WORD *aligned_addr;
92
93 if (CYG_LIBC_STR_UNALIGNED (s))
94 {
95 while (*s)
96 s++;
97 retval = s - start;
98
99 CYG_REPORT_RETVAL( retval );
100
101 return retval;
102 }
103
104 // If the string is word-aligned, we can check for the presence of
105 // a null in each word-sized block.
106
107 aligned_addr = (CYG_WORD *)s;
108 while (!CYG_LIBC_STR_DETECTNULL (*aligned_addr))
109 aligned_addr++;
110
111 // Once a null is detected, we check each byte in that block for a
112 // precise position of the null.
113 s = (char*)aligned_addr;
114 while (*s)
115 s++;
116 retval = s - start;
117
118 CYG_REPORT_RETVAL( retval );
119
120 return retval;
121 #endif // not defined(CYGIMP_LIBC_STRING_PREFER_SMALL_TO_FAST) ||
122 // defined(__OPTIMIZE_SIZE__)
123 } // __strlen()
124
125 // EOF strlen.cxx