Provided by: libglib2.0-dev-bin_2.64.6-1~ubuntu20.04.6_amd64 
NAME
glib-genmarshal - C code marshaller generation utility for GLib closures
SYNOPSIS
glib-genmarshal [OPTION...] [FILE...]
DESCRIPTION
glib-genmarshal is a small utility that generates C code marshallers for callback
functions of the GClosure mechanism in the GObject sublibrary of GLib. The marshaller
functions have a standard signature, they get passed in the invoking closure, an array of
value structures holding the callback function parameters and a value structure for the
return value of the callback. The marshaller is then responsible to call the respective C
code function of the closure with all the parameters on the stack and to collect its
return value.
glib-genmarshal takes a list of marshallers to generate as input. The marshaller list is
either read from files passed as additional arguments on the command line; or from
standard input, by using - as the input file.
Marshaller list format
The marshaller lists are processed line by line, a line can contain a comment in the form
of
or a marshaller specification of the form
RTYPE:PTYPE
RTYPE:PTYPE,PTYPE
RTYPE:PTYPE,PTYPE,PTYPE
The RTYPE part specifies the callback's return type and the PTYPEs right to the colon
specify the callback's parameter list, except for the first and the last arguments which
are always pointers.
Parameter types
Currently, the following types are supported:
VOID
indicates no return type, or no extra parameters. If VOID is used as the parameter
list, no additional parameters may be present.
BOOLEAN
for boolean types (gboolean)
CHAR
for signed char types (gchar)
UCHAR
for unsigned char types (guchar)
INT
for signed integer types (gint)
UINT
for unsigned integer types (guint)
LONG
for signed long integer types (glong)
ULONG
for unsigned long integer types (gulong)
INT64
for signed 64bit integer types (gint64)
UINT64
for unsigned 64bit integer types (guint64)
ENUM
for enumeration types (gint)
FLAGS
for flag enumeration types (guint)
FLOAT
for single-precision float types (gfloat)
DOUBLE
for double-precision float types (gdouble)
STRING
for string types (gchar*)
BOXED
for boxed (anonymous but reference counted) types (GBoxed*)
PARAM
for GParamSpec or derived types (GParamSpec*)
POINTER
for anonymous pointer types (gpointer)
OBJECT
for GObject or derived types (GObject*)
VARIANT
for GVariant types (GVariant*)
NONE
deprecated alias for VOID
BOOL
deprecated alias for BOOLEAN
OPTIONS
--header
Generate header file contents of the marshallers. This option is mutually exclusive
with the --body option.
--body
Generate C code file contents of the marshallers. This option is mutually exclusive
with the --header option.
--prefix=PREFIX
Specify marshaller prefix. The default prefix is `g_cclosure_user_marshal'.
--skip-source
Skip source location remarks in generated comments.
--stdinc
Use the standard marshallers of the GObject library, and include glib-object.h in
generated header files. This option is mutually exclusive with the --nostdinc option.
--nostdinc
Do not use the standard marshallers of the GObject library, and skip glib-object.h
include directive in generated header files. This option is mutually exclusive with
the --stdinc option.
--internal
Mark generated functions as internal, using G_GNUC_INTERNAL.
--valist-marshallers
Generate valist marshallers, for use with g_signal_set_va_marshaller().
-v, --version
Print version information.
--g-fatal-warnings
Make warnings fatal, that is, exit immediately once a warning occurs.
-h, --help
Print brief help and exit.
-v, --version
Print version and exit.
--output=FILE
Write output to FILE instead of the standard output.
--prototypes
Generate function prototypes before the function definition in the C source file, in
order to avoid a missing-prototypes compiler warning. This option is only useful when
using the --body option.
--pragma-once
Use the once pragma instead of an old style header guard when generating the C header
file. This option is only useful when using the --header option.
--include-header=HEADER
Adds a #include directive for the given file in the C source file. This option is only
useful when using the --body option.
-D SYMBOL[=VALUE]
Adds a #define C pre-processor directive for SYMBOL and its given VALUE, or "1" if the
value is unset. You can use this option multiple times; if you do, all the symbols
will be defined in the same order given on the command line, before the symbols
undefined using the -U option. This option is only useful when using the --body
option.
-U SYMBOL
Adds a #undef C pre-processor directive to undefine the given SYMBOL. You can use this
option multiple times; if you do, all the symbols will be undefined in the same order
given on the command line, after the symbols defined using the -D option. This option
is only useful when using the --body option.
--quiet
Minimizes the output of glib-genmarshal, by printing only warnings and errors. This
option is mutually exclusive with the --verbose option.
--verbose
Increases the verbosity of glib-genmarshal, by printing debugging information. This
option is mutually exclusive with the --quiet option.
USING GLIB-GENMARSHAL WITH MESON
Meson supports generating closure marshallers using glib-genmarshal out of the box in its
"gnome" module.
In your meson.build file you will typically call the gnome.genmarshal() method with the
source list of marshallers to generate:
gnome = import('gnome')
marshal_files = gnome.genmarshal('marshal',
sources: 'marshal.list',
internal: true,
)
The marshal_files variable will contain an array of two elements in the following order:
• a build target for the source file
• a build target for the header file
You should use the returned objects to provide a dependency on every other build target
that references the source or header file; for instance, if you are using the source to
build a library:
mainlib = library('project',
sources: project_sources + marshal_files,
...
)
Additionally, if you are including the generated header file inside a build target that
depends on the library you just built, you must ensure that the internal dependency
includes the generated header as a required source file:
mainlib_dep = declare_dependency(sources: marshal_files[1], link_with: mainlib)
You should not include the generated source file as well, otherwise it will be built
separately for every target that depends on it, causing build failures. To know more about
why all this is required, please refer to the corresponding Meson FAQ entry[1].
For more information on how to use the method, see the Meson documentation for
gnome.genmarshal()[2].
USING GLIB-GENMARSHAL WITH AUTOTOOLS
In order to use glib-genmarshal in your project when using Autotools as the build system,
you will first need to modify your configure.ac file to ensure you find the appropriate
command using pkg-config, similarly as to how you discover the compiler and linker flags
for GLib.
PKG_PROG_PKG_CONFIG([0.28])
PKG_CHECK_VAR([GLIB_GENMARSHAL], [glib-2.0], [glib_genmarshal])
In your Makefile.am file you will typically need very simple rules to generate the C files
needed for the build.
marshal.h: marshal.list
$(AM_V_GEN)$(GLIB_GENMARSHAL) \
--header \
--output=$@ \
$<
marshal.c: marshal.list marshal.h
$(AM_V_GEN)$(GLIB_GENMARSHAL) \
--include-header=marshal.h \
--body \
--output=$@ \
$<
BUILT_SOURCES += marshal.h marshal.c
CLEANFILES += marshal.h marshal.c
EXTRA_DIST += marshal.list
In the example above, the first rule generates the header file and depends on a
marshal.list file in order to regenerate the result in case the marshallers list is
updated. The second rule generates the source file for the same marshal.list, and includes
the file generated by the header rule.
EXAMPLE
To generate marshallers for the following callback functions:
void foo (gpointer data1,
gpointer data2);
void bar (gpointer data1,
gint param1,
gpointer data2);
gfloat baz (gpointer data1,
gboolean param1,
guchar param2,
gpointer data2);
The marshaller.list file has to look like this:
VOID:VOID
VOID:INT
FLOAT:BOOLEAN,UCHAR
and you call glib-genmarshal like this:
glib-genmarshal --header marshaller.list > marshaller.h
glib-genmarshal --body marshaller.list > marshaller.c
The generated marshallers have the arguments encoded in their function name. For this
particular list, they are
g_cclosure_user_marshal_VOID__VOID(...),
g_cclosure_user_marshal_VOID__INT(...),
g_cclosure_user_marshal_FLOAT__BOOLEAN_UCHAR(...).
They can be used directly for GClosures or be passed in as the GSignalCMarshaller
c_marshaller; argument upon creation of signals:
GClosure *cc_foo, *cc_bar, *cc_baz;
cc_foo = g_cclosure_new (NULL, foo, NULL);
g_closure_set_marshal (cc_foo, g_cclosure_user_marshal_VOID__VOID);
cc_bar = g_cclosure_new (NULL, bar, NULL);
g_closure_set_marshal (cc_bar, g_cclosure_user_marshal_VOID__INT);
cc_baz = g_cclosure_new (NULL, baz, NULL);
g_closure_set_marshal (cc_baz, g_cclosure_user_marshal_FLOAT__BOOLEAN_UCHAR);
SEE ALSO
glib-mkenums(1)
NOTES
1. corresponding Meson FAQ entry
https://mesonbuild.com/FAQ.html#how-do-i-tell-meson-that-my-sources-use-generated-headers
2. Meson documentation for gnome.genmarshal()
https://mesonbuild.com/Gnome-module.html#gnomegenmarshal