symbol.h

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/*
 * Copyright (c) 2023 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_LLEXT_SYMBOL_H
#define ZEPHYR_LLEXT_SYMBOL_H
 
#include <zephyr/sys/iterable_sections.h>
#include <zephyr/toolchain.h>
#include <stddef.h>
#include <stdint.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
struct llext_const_symbol {
        union {
                const char *const name;
 
                const uintptr_t slid;
        };
 
        const void *const addr;
};
BUILD_ASSERT(sizeof(struct llext_const_symbol) == 2 * sizeof(uintptr_t));
 
struct llext_symbol {
        const char *name;
 
        void *addr;
};
 
 
struct llext_symtable {
        size_t sym_cnt;
 
        struct llext_symbol *syms;
};
 
 
#ifdef LL_EXTENSION_BUILD
/* Extension build: add exported symbols to llext table */
#define Z_LL_EXTENSION_SYMBOL(x)                                                \
        static const struct llext_const_symbol                                  \
                        Z_GENERIC_SECTION(".exported_sym") __used               \
                        __llext_sym_ ## x = {                                   \
                .name = STRINGIFY(x), .addr = (const void *)&x,                 \
        }
#else
/* No-op when not building an extension */
#define Z_LL_EXTENSION_SYMBOL(x)
#endif
#define LL_EXTENSION_SYMBOL(x) Z_LL_EXTENSION_SYMBOL(x)
 
#if defined(LL_EXTENSION_BUILD)
/* Extension build: EXPORT_SYMBOL maps to LL_EXTENSION_SYMBOL */
#define Z_EXPORT_SYMBOL(x) Z_LL_EXTENSION_SYMBOL(x)
#elif defined(CONFIG_LLEXT_EXPORT_BUILTINS_BY_SLID)
/* SLID-enabled LLEXT application: export symbols, names in separate section */
#define Z_EXPORT_SYMBOL(x)                                                      \
        static const char Z_GENERIC_SECTION("llext_exports_strtab") __used      \
                __llext_sym_name_ ## x[] = STRINGIFY(x);                                \
        static const STRUCT_SECTION_ITERABLE(llext_const_symbol,                \
                                             __llext_sym_ ## x) = {             \
                .name = __llext_sym_name_ ## x, .addr = (const void *)&x,               \
        }
#elif defined(CONFIG_LLEXT)
/* LLEXT application: export symbols */
#define Z_EXPORT_SYMBOL(x)                                                      \
        static const STRUCT_SECTION_ITERABLE(llext_const_symbol,                \
                                             __llext_sym_ ## x) = {             \
                .name = STRINGIFY(x), .addr = (const void *)&x,                 \
        }
#else
/* No extension support in this build */
#define Z_EXPORT_SYMBOL(x)
#endif
#define EXPORT_SYMBOL(x) Z_EXPORT_SYMBOL(x)
 
#ifdef __cplusplus
}
#endif
 
 
#endif /* ZEPHYR_LLEXT_SYMBOL_H */