Generation of C language header files defining the interface to a library is performed using python and an XML schema. The XML schema describes the interface to be generated by the python script.
The schema is designed to follow as closely as possible the C language syntax which it is generating.
The schema is defined as an XML document which takes the form.
<?xml version="1.0"?>
<interface>
<!-- xml elements describing the API interface -->
</interface>Ordering of tags within the <interface></interface> tags are preserved.
To insert an include directive into the header use the include tag. By default
the angle bracket form is generated although this can also be specified
explicitly; this is done using the form attribute which can be set to either
angle outputting the angle bracket form or quote producing the quotation
mark form.
<include>stddef.h</include>
<include form="angle">stdint.h</include>
<include form="quote">myheader.h</include>Will result in the following include directive being generated.
#include <stddef.h>
#include <stdint.h>
#include "myheader.h"Insertion of macro definition is done using the define tag which comes in
three forms. For the first form only the macro name is required, use the value
tag to if a value is required; function like macros can be created using the
param tag with a name.
<define>HAVE_FEATURE</define>
<define>PI<value>3.14</value></define>
<define>UNUSED<param>VARIABLE</param><value>(void)VARIABLE;</value></define>
<define>ASSERT<param>CONDITION</param><param>MESSAGE</param>
<value>if (CONDITION) {
fprintf(stderr, MESSAGE);
abort();
}</value></define>Will generate the following macro definitions.
#define TAG
#define PI 3.14
#define UNUSED(VARIABLE) (void)VARIABLE;
#define ASSERT(CONDITION, MESSAGE) \
if (CONDITION) { \
fprintf(stderr, MESSAGE); \
abort(); \
}
Note that new lines in multi line value tags will be escaped automatically.
Introducing structures is done using the struct tag which can be used to
describe forward declarations, empty structures, and structures with member
objects. Providing only the structure name as the text to the struct tag will
result in a forward declaration; an empty body tag results in an empty
structure, finally using the body tag with a number of nested member tags
containing optional name text and a mandatory type tag produces a structure
with member objects.
<struct>forward_t</struct>
<struct>empty_t<member></member></struct>
<struct>position_t<body>
<member>x<type>float</type></member>
<member>y<type>float</type></member>
</body></struct>This outputs the following set of structure output.
struct forward_decl_t;
struct empty_t {};
struct position_t {
float x;
float y;
};Generation of enumerations is done using the enum tag, this is functionally
equivalent to a structure with nested member objects. An
<enum>positions<body>
<constant>CENTER</constant>
<constant>LEFT<value>-1</value></constant>
<constant>RIGHT<value>1</value></constant>
</body></enum>
<enum><body>
<constant>SUCCESS</constant>
<constant>FAILURE</constant>
</body></enum>Will generate the following C code.
enum positions {
CENTER,
LEFT = -1,
RIGHT = 1
};
enum {
SUCCESS,
FAILURE
};<function>nop<return>void</return></function>
<function>foo<return>uint32_t</return>
<param>count<type>uint32_t</type></param>
</function>
<function>main<return>int</return>
<param>argc<type>int</type></param>
<param>argv<type>char **</type></param>
</function>void nop();
uint32_t foo(uint32_t count);
int main(int argc, char ** argv);Copyright (c) 2015 Kenneth Benzie
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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