| 1 |
|
|---|
| 2 | Implementation notes:
|
|---|
| 3 |
|
|---|
| 4 | This is a true OS/400 implementation, not a PASE implementation (for PASE,
|
|---|
| 5 | use an AIX implementation).
|
|---|
| 6 |
|
|---|
| 7 | The biggest problem with OS/400 is EBCDIC. The current libxml2 implementation
|
|---|
| 8 | uses UTF-8 internally. To ease encoding conversion between the calling
|
|---|
| 9 | applications and libxml2, supplementary "convert and latch" functions are
|
|---|
| 10 | provided (See below). To bind the EBCDIC OS/400 system calls and libxml2,
|
|---|
| 11 | an ASCII run-time environment (QADRT) has been used and wrapper functions have
|
|---|
| 12 | been designed.
|
|---|
| 13 |
|
|---|
| 14 | Other problems are:
|
|---|
| 15 | - Source code line length: to be stored in DB2 members, source files may not
|
|---|
| 16 | have lines longer than 100 characters. Some header and documentation files
|
|---|
| 17 | have been modified accordingly.
|
|---|
| 18 | - va_list dereferencing: the OS/400 implementation of va_list type is an array
|
|---|
| 19 | but the compiler forbids explicit array dereferencing. Source files have
|
|---|
| 20 | been updated accordingly.
|
|---|
| 21 | - Depending on the compilation/execution environment, it is possible that
|
|---|
| 22 | stdin/stdout/stderr are not associated with a file descriptor; as a side
|
|---|
| 23 | effect, open() may return a file descriptor value 0, 1 or 2 that is NOT
|
|---|
| 24 | a C standard file. Thus using such a number may be inaccurate.
|
|---|
| 25 | - iconv_open() arguments: OS/400 uses non-standard encoding names and does not
|
|---|
| 26 | support standard names. For this reason, a name wrapper has been designed.
|
|---|
| 27 | - dlopen() (support for xmodule): the function and its corollaries are not
|
|---|
| 28 | provided by the OS/400 library. However a local implementation is provided.
|
|---|
| 29 |
|
|---|
| 30 |
|
|---|
| 31 | Compiling on OS/400:
|
|---|
| 32 |
|
|---|
| 33 | _ As a prerequisite, QADRT development environment must be installed.
|
|---|
| 34 | _ Install the libxml2 source directory in IFS.
|
|---|
| 35 | _ Enter shell (QSH)
|
|---|
| 36 | _ Change current directory to the libxml2 installation directory
|
|---|
| 37 | _ Change current directory to ./os400
|
|---|
| 38 | _ Edit file iniscript.sh. You may want to change tunable configuration
|
|---|
| 39 | parameters, like debug info generation, optimisation level, listing option,
|
|---|
| 40 | target library, zlib availability, etc.
|
|---|
| 41 | _ Copy any file in the current directory to makelog (i.e.:
|
|---|
| 42 | cp initscript.sh makelog): this is intended to create the makelog file with
|
|---|
| 43 | an ASCII CCSID!
|
|---|
| 44 | _ Enter the command "sh make.sh >makelog 2>&1'
|
|---|
| 45 | _ Examine the makelog file to check for compilation errors.
|
|---|
| 46 |
|
|---|
| 47 | Leaving file initscript.sh unchanged, this will produce the following
|
|---|
| 48 | OS/400 objects:
|
|---|
| 49 | _ Library LIBXML2. All other objects will be stored in this library.
|
|---|
| 50 | _ Modules for all libxml2 units, with full debug info and no code optimization.
|
|---|
| 51 | _ Binding directory LIBXML2_A, to be used at calling program link time for
|
|---|
| 52 | statically binding the modules (specify BNDSRVPGM(QADRTTS QGLDCLNT QGLDBRDR)
|
|---|
| 53 | when creating a program using LIBXML2_A).
|
|---|
| 54 | _ Service program LIBXML2. To be used at calling program run-time
|
|---|
| 55 | when this program has dynamically bound libxml2 at link time.
|
|---|
| 56 | _ Binding directory LIBXML2. To be used to dynamically bind libxml2 when
|
|---|
| 57 | linking a calling program.
|
|---|
| 58 | _ Source file LIBXML. It contains all the header members needed to compile a
|
|---|
| 59 | C/C++ module using libxml2.
|
|---|
| 60 | _ Standard and additional C/C++ libxml2 header members (possibly renamed) in
|
|---|
| 61 | file LIBXML.
|
|---|
| 62 | _ IFS directory /libxml2 with subdirectory include/libxml containing all
|
|---|
| 63 | C/C++ header files for IFS-based compilation.
|
|---|
| 64 | _ Source file LIBXMLRPG. It contains all the include members needed to compile a
|
|---|
| 65 | ILE/RPG module/program using libxml2 (ILE/RPG binding).
|
|---|
| 66 | _ ILE/RPG binding include members (possibly renamed) in file LIBXMLRPG.
|
|---|
| 67 | _ IFS subdirectory /libxml2/include/libxmlrpg containing all ILE/RPG include
|
|---|
| 68 | files for IFS-based compilation.
|
|---|
| 69 |
|
|---|
| 70 |
|
|---|
| 71 | Renamed header files in DB2 members:
|
|---|
| 72 | DB2 member names are limited to 10 characters, thus the following C/C++
|
|---|
| 73 | header members are renamed as:
|
|---|
| 74 | parserInternals.h --> PARSERINTE
|
|---|
| 75 | schemasInternals.h --> SCHEMASINT
|
|---|
| 76 | xmlautomata.h --> XMLAUTOMAT
|
|---|
| 77 | xmlschemastype.h --> SCHMTYPES
|
|---|
| 78 | xpathInternals.h --> XPATHINTER
|
|---|
| 79 | IFS header files are NOT renamed.
|
|---|
| 80 | ILE/RPG headers are processed likewise.
|
|---|
| 81 |
|
|---|
| 82 |
|
|---|
| 83 | Special programming consideration:
|
|---|
| 84 |
|
|---|
| 85 | QADRT being used, the following points must be considered:
|
|---|
| 86 | _ If static binding is used, service program QADRTTS must be linked too.
|
|---|
| 87 | _ The EBCDIC CCSID used by QADRT is 37 by default, NOT THE JOB'S CCSID. If
|
|---|
| 88 | another EBCDIC CCSID is required, it must be set via a locale through a call
|
|---|
| 89 | to setlocale_a (QADRT's setlocale() ASCII wrapper) with category LC_ALL or
|
|---|
| 90 | LC_CTYPE, or by setting environment variable QADRT_ENV_LOCALE to the locale
|
|---|
| 91 | object path before executing the program.
|
|---|
| 92 | _ Always use *IFSIO or *IFS64IO to compile calling programs.
|
|---|
| 93 |
|
|---|
| 94 |
|
|---|
| 95 |
|
|---|
| 96 | Supplementary (non libxml2 standard) support procedures for OS/400.
|
|---|
| 97 |
|
|---|
| 98 | As cited above, there are some procedures to ease encoding conversion of
|
|---|
| 99 | libxml2 function arguments and results: the mechanism is based on
|
|---|
| 100 | dictionaries. The functions convert a string, latch the result in a dictionary
|
|---|
| 101 | to ensure its persistence and return its address. It is the caller's
|
|---|
| 102 | responsibility to clean the dictionary when it becomes too big or disappears.
|
|---|
| 103 |
|
|---|
| 104 | The procedures are:
|
|---|
| 105 |
|
|---|
| 106 | #include <libxml/transcode.h>
|
|---|
| 107 |
|
|---|
| 108 | const char * xmlTranscodeResult(const xmlChar * s,
|
|---|
| 109 | const char * encoding,
|
|---|
| 110 | xmlDictPtr * dict,
|
|---|
| 111 | void (*freeproc)(const void *));
|
|---|
| 112 |
|
|---|
| 113 | const xmlChar * xmlTranscodeString(const char * s,
|
|---|
| 114 | const char * encoding,
|
|---|
| 115 | xmlDictPtr * dict);
|
|---|
| 116 |
|
|---|
| 117 | const xmlChar * xmlTranscodeWString(const char * s,
|
|---|
| 118 | const char * encoding,
|
|---|
| 119 | xmlDictPtr * dict);
|
|---|
| 120 |
|
|---|
| 121 | const xmlChar * xmlTranscodeWString(const char * s,
|
|---|
| 122 | const char * encoding,
|
|---|
| 123 | xmlDictPtr * dict);
|
|---|
| 124 |
|
|---|
| 125 | where:
|
|---|
| 126 | s is the string to translate.
|
|---|
| 127 | encoding is the alternate character encoding. If null, the current job's
|
|---|
| 128 | encoding (CCSID) is used.
|
|---|
| 129 | dict is the address of the latching directory. If NULL, the procedure
|
|---|
| 130 | functions as a simple non-latching encoding converter and
|
|---|
| 131 | its result value should be freed by the caller.
|
|---|
| 132 | freeproc is a procedure to release the original string, or NULL.
|
|---|
| 133 |
|
|---|
| 134 | xmlTranscodeResult() converts from UTF-8 to the given alternate encoding.
|
|---|
| 135 | xmlTranscodeString() converts from the given 8-bit encoding to UTF-8 (note that
|
|---|
| 136 | UTF-8 itself is considered as a 8-bit encoding).
|
|---|
| 137 | xmlTranscodeWString() converts from the given 16-bit encoding to UTF-8.
|
|---|
| 138 | xmlTranscodeHString() converts from the given 32-bit encoding to UTF-8.
|
|---|
| 139 |
|
|---|
| 140 |
|
|---|
| 141 | To shorten statements using these functions, shorthands are defined:
|
|---|
| 142 |
|
|---|
| 143 | xmlTR for xmlTranscodeResult
|
|---|
| 144 | xmlTS for xmlTranscodeString
|
|---|
| 145 | xmlTW for xmlTranscodeWString
|
|---|
| 146 | xmlTH for xmlTranscodeHstring
|
|---|
| 147 |
|
|---|
| 148 | These shorthands may be disabled by defining XML_NO_SHORT_NAMES before
|
|---|
| 149 | libxml/transcode.h inclusion.
|
|---|
| 150 |
|
|---|
| 151 | A directory pointer must be preset to NULL before the first call using it to
|
|---|
| 152 | one of the above procedure.
|
|---|
| 153 |
|
|---|
| 154 | To release a latching directory, use function
|
|---|
| 155 |
|
|---|
| 156 | void xmlZapDict(xmlDictPtr * dict);
|
|---|
| 157 |
|
|---|
| 158 |
|
|---|
| 159 | Example:
|
|---|
| 160 |
|
|---|
| 161 | #include <libxml/transcode.h>
|
|---|
| 162 | #include <libxml/tree.h>
|
|---|
| 163 |
|
|---|
| 164 | xmlDocPtr mySimpleXMLDoc(char * element, char * text)
|
|---|
| 165 | {
|
|---|
| 166 | xmlDocPtr doc;
|
|---|
| 167 | xmlNodePtr node;
|
|---|
| 168 | xmlDictPtr dict = NULL;
|
|---|
| 169 |
|
|---|
| 170 | /* element and text are encoded in the current job's encoding. */
|
|---|
| 171 |
|
|---|
| 172 | doc = xmlNewDoc();
|
|---|
| 173 | xmlNewTextChild((xmlNodePtr) doc, NULL, xmlTS(element, NULL,
|
|---|
| 174 | &dict), xmlTS(text, NULL, &dict));
|
|---|
| 175 | xmlZapDict(&dict);
|
|---|
| 176 | return doc;
|
|---|
| 177 | }
|
|---|
| 178 |
|
|---|
| 179 |
|
|---|
| 180 | Additionally, a formatter into latched/dynamic storage is provided:
|
|---|
| 181 |
|
|---|
| 182 | const char * xmlVasprintf(xmlDictPtr * dict,
|
|---|
| 183 | const char * encoding,
|
|---|
| 184 | const xmlChar * fmt,
|
|---|
| 185 | va_list args);
|
|---|
| 186 |
|
|---|
| 187 |
|
|---|
| 188 | xmllint and xmlcatalog programs:
|
|---|
| 189 |
|
|---|
| 190 | These programs are fully implemented at the qshell level, with standard
|
|---|
| 191 | command line options. Links to these are installed in sub-directory bin of
|
|---|
| 192 | the IFS installation directory.
|
|---|
| 193 | CL command interfaces to these programs are also provided with limited
|
|---|
| 194 | support. In particular, interactive mode is not supported and argument count
|
|---|
| 195 | and lengths are limited by the CL command syntax.
|
|---|
| 196 |
|
|---|
| 197 |
|
|---|
| 198 | ILE/RPG binding:
|
|---|
| 199 |
|
|---|
| 200 | All standard types and procedures are provided. Since ILE/RPG does not
|
|---|
| 201 | support macros, they have not been ported. However some of them are emulated
|
|---|
| 202 | as functions: these are the more useful ones (xmlXPathNodeSetGetLength,
|
|---|
| 203 | xmlXPathNodeSetItem, xmlXPathNodeSetIsEmpty, htmlDefaultSubelement,
|
|---|
| 204 | htmlElementAllowedHereDesc, htmlRequiredAttrs) and the global/threaded
|
|---|
| 205 | variables access macros. These variables can be read with function
|
|---|
| 206 | get_xxx(void), where xxxx is the name of the variable; they may be set by
|
|---|
| 207 | calling function set_xxxx(value), where value is of the same type as the
|
|---|
| 208 | variable.
|
|---|
| 209 |
|
|---|
| 210 | The C va_list is not implemented as such in ILE/RPG. Functions implementing
|
|---|
| 211 | va_list and associated methods are provided:
|
|---|
| 212 |
|
|---|
| 213 | /include "libxmlrpg/xmlstdarg"
|
|---|
| 214 |
|
|---|
| 215 | d xmlVaStart pr
|
|---|
| 216 | d list like(xmlVaList)
|
|---|
| 217 | d lastargaddr * value
|
|---|
| 218 | d lastargsize 10u 0 value
|
|---|
| 219 |
|
|---|
| 220 | d xmlVaArg pr
|
|---|
| 221 | d list like(xmlVaList)
|
|---|
| 222 | d dest * value
|
|---|
| 223 | d argsize 10i 0 value
|
|---|
| 224 |
|
|---|
| 225 | d xmlVaEnd pr
|
|---|
| 226 | d list like(xmlVaList)
|
|---|
