1Gtk2::CodeGen(3) User Contributed Perl Documentation Gtk2::CodeGen(3)
2
6 Gtk2::CodeGen - code generation utilities for Glib-based bindings.
7
9 # usually in Makefile.PL
10 use Gtk2::CodeGen;
11 # most common, use all defaults
13 Gtk2::CodeGen->parse_maps ('myprefix');
14 Gtk2::CodeGen->write_boot;
15 # more exotic, change everything
17 Gtk2::CodeGen->parse_maps ('foo',
18 input => 'foo.maps',
19 header => 'foo-autogen.h',
20 typemap => 'foo.typemap',
21 register => 'register-foo.xsh');
22 Gtk2::CodeGen->write_boot (filename => 'bootfoo.xsh',
23 glob => 'Foo*.xs',
24 ignore => '^(Foo|Foo::Bar)$');
25
27 This module packages some of the boilerplate code needed for performing
28 code generation typically used by perl bindings for gobject-based
29 libraries, using the Glib module as a base.
30 The default output filenames are in the subdirectory 'build', which
32 usually will be present if you are using ExtUtils::Depends (as most
33 Glib-based extensions probably should).
34 METHODS
36 Gtk2::CodeGen->write_boot;
37 Gtk2::CodeGen->write_boot (KEY => VAL, ...)
38 Many GObject-based libraries to be bound to perl will be too large
39 to put in a single XS file; however, a single PM file typically
40 only bootstraps one XS file's code. "write_boot" generates an XSH
41 file to be included from the BOOT section of that one bootstrapped
42 module, calling the boot code for all the other XS files in the
43 project.
44 Options are passed to the function in a set of key/val pairs, and
46 all options may default.
47 filename the name of the output file to be created.
49 the default is 'build/boot.xsh'.
50 glob a glob pattern that specifies the names of
52 the xs files to scan for MODULE lines.
53 the default is 'xs/*.xs'.
54 xs_files use this to supply an explicit list of file
56 names (as an array reference) to use instead
57 of a glob pattern. the default is to use
58 the glob pattern.
59 ignore regular expression matching any and all
61 module names which should be ignored, i.e.
62 NOT included in the list of symbols to boot.
63 this parameter is extremely important for
64 avoiding infinite loops at startup; see the
65 discussion for an explanation and rationale.
66 the default is '^[^:]+$', or, any name that
67 contains no colons, i.e., any toplevel
68 package name.
69 This function performs a glob (using perl's builtin glob operator)
71 on the pattern specified by the 'glob' option to retrieve a list of
72 file names. It then scans each file in that list for lines
73 matching the pattern "^MODULE" -- that is, the MODULE directive in
74 an XS file. The module name is pulled out and matched against the
75 regular expression specified by the ignore parameter. If this
76 module is not to be ignored, we next check to see if the name has
77 been seen. If not, the name will be converted to a boot symbol
78 (basically, s/:/_/ and prepend "boot_") and this symbol will be
79 added to a call to GPERL_CALL_BOOT in the generated file; it is
80 then marked as seen so we don't call it again.
81 What is this all about, you ask? In order to bind an XSub to perl,
83 the C function must be registered with the interpreter. This is
84 the function of the "boot" code, which is typically called in the
85 bootstrapping process. However, when multiple XS files are used
86 with only one PM file, some other mechanism must call the boot code
87 from each XS file before any of the function therein will be
88 available.
89 A typical setup for a multiple-XS, single-PM module will be to call
91 the various bits of boot code from the BOOT: section of the
92 toplevel module's XS file.
93 To use Gtk2 as an example, when you do 'use Gtk2', Gtk2.pm calls
95 bootstrap on Gtk2, which calls the C function boot_Gtk2. This
96 function calls the boot symbols for all the other xs files in the
97 module. The distinction is that the toplevel module, Gtk2, has no
98 colons in its name.
99 "xsubpp" generates the boot function's name by replacing the colons
101 in the MODULE name with underscores and prepending "boot_". We
102 need to be careful not to include the boot code for the
103 bootstrapped module, (say Toplevel, or Gtk2, or whatever) because
104 the bootstrap code in Toplevel.pm will call boot_Toplevel when
105 loaded, and boot_Toplevel should actually include the file we are
106 creating here.
107 The default value for the ignore parameter ignores any name not
109 containing colons, because it is assumed that this will be a
110 toplevel module, and any other packages/modules it boots will be
111 below this namespace, i.e., they will contain colons. This
112 assumption holds true for Gtk2 and Gnome2, but obviously fails for
113 something like Gnome2::Canvas. To boot that module properly, you
114 must use a regular expression such as "^Gnome2::Canvas$".
115 Note that you can, of course, match more than just one name, e.g.
117 "^(Foo|Foo::Bar)$", if you wanted to have Foo::Bar be included in
118 the same dynamically loaded object but only be booted when
119 absolutely necessary. (If you get that to work, more power to
120 you.)
121 Also, since this code scans for ^MODULE, you must comment the
123 MODULE section out with leading # marks if you want to hide it from
124 "write_boot".
125 Gtk2::CodeGen->parse_maps (PREFIX, [KEY => VAL, ...])
127 Convention within Glib/Gtk2 and friends is to use preprocessor
128 macros in the style of SvMyType and newSVMyType to get values in
129 and out of perl, and to use those same macros from both hand-
130 written code as well as the typemaps. However, if you have a lot
131 of types in your library (such as the nearly 200 types in Gtk+
132 2.x), then writing those macros becomes incredibly tedious,
133 especially so when you factor in all of the variants and such.
134 So, this function can turn a flat file containing terse
136 descriptions of the types into a header containing all the cast
137 macros, a typemap file using them, and an XSH file containing the
138 proper code to register each of those types (to be included by your
139 module's BOOT code).
140 The PREFIX is mandatory, and is used in some of the resulting
142 filenames, You can also override the defaults by providing key=>val
143 pairs:
144 input input file name. default is 'maps'. if this
146 key's value is an array reference, all the
147 filenames in the array will be scanned.
148 header name of the header file to create, default is
149 build/$prefix-autogen.h
150 typemap name of the typemap file to create, default is
151 build/$prefix.typemap
152 register name of the xsh file to contain all of the
153 type registrations, default is build/register.xsh
154 the maps file is a table of type descriptions, one per line, with
156 fields separated by whitespace. the fields should be:
157 TYPE macro e.g., GTK_TYPE_WIDGET
159 class name e.g. GtkWidget, name of the C type
160 base type one of GObject, GBoxed, GEnum, GFlags.
161 GtkObject is also supported, but the
162 distinction is no longer necessary as
163 of Glib 0.26.
164 package name of the perl package to which this
165 class name should be mapped, e.g.
166 Gtk2::Widget
167 As a special case, you can also use this same format to register
169 error domains; in this case two of the four columns take on
170 slightly different meanings:
171 domain macro e.g., GDK_PIXBUF_ERROR
173 enum type macro e.g., GDK_TYPE_PIXBUF_ERROR
174 base type GError
175 package name of the Perl package to which this
176 class name should be mapped, e.g.,
177 Gtk2::Gdk::Pixbuf::Error.
178 Gtk2::CodeGen->generate_constants_wrappers (KEY => VAL, ...)
180 Generates an XS file with XSUB wrappers for C constants. The key-
181 value pairs may contain one or more of the following keys:
182 prefix: Specifies the package name the functions should be put
184 into.
185 lists: Reference to an array of filenames which specify the
186 constants that should be wrapped.
187 xs_file: The name of the XS file that should be created.
188 header: The name of the header file that should be included in the
189 generated XS file.
190 export_tag: The name of the Exporter tag that should be used for
191 the constants wrappers.
192 All of the keys have mostly sane defaults.
194 Don't forget to add the generated XS file to the list of XS files
196 to be compiled.
197 The lists describing the constants to be wrapped should have the
199 following format:
200 CONSTANT_NAME [ \t+ CONSTANT_CONVERTER ]
202 That is, the constant's name optionally followed by a tab and the
204 converter that is to be used to convert the constant to a Perl
205 scalar. If CONSTANT_CONVERTER is a simple string like 'newSViv' it
206 will be used as follows to get a Perl scalar: CONSTANT_CONVERTER
207 (CONSTANT_NAME). If it contains '$var', as in 'newSVpv ($var, 0)',
208 then '$var' will be replaced with CONSTANT_NAME and the resulting
209 string will be used for conversion.
210 The default for CONSTANT_CONVERTER is 'newSViv'.
212
214 Glib::CodeGen does the actual work; Gtk2::CodeGen is now just a wrapper
215 which adds support for gtk-specific types.
216
218 muppet <scott at asofyet dot org>
219
221 Copyright (C) 2003-2005, 2013 by the gtk2-perl team (see the file
222 AUTHORS for the full list)
223 This library is free software; you can redistribute it and/or modify it
225 under the terms of the GNU Library General Public License as published
226 by the Free Software Foundation; either version 2.1 of the License, or
227 (at your option) any later version.
228 This library is distributed in the hope that it will be useful, but
230 WITHOUT ANY WARRANTY; without even the implied warranty of
231 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
232 Library General Public License for more details.
233 You should have received a copy of the GNU Library General Public
235 License along with this library; if not, write to the Free Software
236 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
237 02110-1301 USA.
238perl v5.30.1 2020-01-30 Gtk2::CodeGen(3)