+++ /dev/null
-/**
-@page GRAS_tut_tour_pointers Lesson 13: Defining structure containing pointers (TODO)
-
-This lesson is a bit different from the other ones. It aims at explaining
-several features of the automatic datadesc parsing. Since it would be a bit
-long otherwise, the lesson is organized as a FAQ, with little examples of
-how to do things.
-
-\section GRAS_tut_tour_pointers_toc Table of Contents
- - \ref GRAS_tut_tour_pointers_intro
- - \ref GRAS_tut_tour_pointers_use
- - \ref GRAS_tut_tour_pointers_recap
- - \ref GRAS_tut_tour_pointers_cste
-
-<hr>
-\section GRAS_tut_tour_pointers_intro Introduction to pointers in datadesc
-\section GRAS_tut_tour_pointers_use Using pointers in datadesc
-\section GRAS_tut_tour_pointers_recap Recapping everything
-
-
-\section GRAS_tut_tour_pointers_cste How to have constants in parsed structures?
-
-You can use gras_datadesc_set_const() to explain GRAS about the value of
-your \#define'd constants.
-
-\verbatim
-#define SIZE 12
-GRAS_DEFINE_TYPE(array,struct array {
- int data[SIZE];
-};);
-
-void declare_ddt() {
- gras_datadesc_type_t ddt;
-
- gras_datadesc_set_const("SIZE",SIZE); /* Set it before */
- gras_datadesc_by_symbol(array);
-}
-\endverbatim
-
-
-*/
-
- and the this example do use structures as payload,
- so we have to declare it to GRAS. Hopefully, this can be done easily by enclosing
- the structure declaration within a \ref GRAS_DEFINE_TYPE macro call. It will then copy this
- declaration into an hidden string variable, which can be automatically parsed at
- run time. Of course, the declaration is also copied unmodified by this macro, so that it
- gets parsed by the compiler also.
-
- There is some semantic that GRAS cannot guess alone and you need to <i>annotate</i>
- your declaration to add some. For example, the ctn pointer can be a reference to an
- object or a whole array (in which case you also has to specify its size). This is done
- with the GRAS_ANNOTE call. It is removed from the text passed to the compiler, but it helps
- GRAS getting some information about the semantic of your data. Here, it says that \a ctn is an
- array, which size is the result of the operation \a rows * \a cols (with \a rows and \a cols
- being the other fields of the structure).
-
- Please note that this annotation mechanism is not as robust and cool as this example seems to
- imply. If you want to use it yourself, you'd better use the exact right syntax, which is
- detailed in the \ref GRAS_dd section.
-
- \skip GRAS_DEFINE_TYPE
- \until matrix_t
-
-
-
-#define COLS 16
-#define MAX_ROUTESET 10
-#define MAX_LEAFSET COLS
-
-GRAS_DEFINE_TYPE(gras_row_t,
-struct gras_row_t {
- int which_row;
- int row[COLS][MAX_ROUTESET];
-};)
-
-typedef struct gras_row_t gras_row_t;
-
-GRAS_DEFINE_TYPE(gras_welcome_msg_t,
-struct gras_welcome_msg_t {
- int id;
- double time_sent;
-
- int row_count;
- gras_row_t *rows GRAS_ANNOTE(size,row_count);
-
- int leaves[MAX_LEAFSET];
-};)
-
-void declare_ddt(void) {
- gras_datadesc_type_t ddt;
-
- gras_datadesc_set_const("COLS",COLS);
- gras_datadesc_set_const("MAX_ROUTESET",MAX_ROUTESET);
- gras_datadesc_set_const("MAX_LEAFSET",MAX_LEAFSET);
-
- gras_datadesc_by_symbol(gras_row_t); /* Parse it before */
- ddt=gras_datadesc_ref("welcome_msg_t*",gras_datadesc_by_symbol(gras_welcome_msg_t));
- gras_msgtype_declare("welcome",ddt);
-}
