dav: comparison ucx/cx/common.h

-:bbe2925eb590
+:83fdf679df99
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
 /**
-* \file common.h
+* @file common.h
 *
-* \brief Common definitions and feature checks.
+* @brief Common definitions and feature checks.
 *
-* \author Mike Becker
+* @author Mike Becker
-* \author Olaf Wintermann
+* @author Olaf Wintermann
-* \copyright 2-Clause BSD License
+* @copyright 2-Clause BSD License
 *
-* \mainpage UAP Common Extensions
+* @mainpage UAP Common Extensions
 * Library with common and useful functions, macros and data structures.
 * <p>
 * Latest available source:<br>
 * <a href="https://sourceforge.net/projects/ucx/files/">https://sourceforge.net/projects/ucx/files/</a>
 * </p>
 #define UCX_VERSION_MINOR   1
 /** Version constant which ensures to increase monotonically. */
 #define UCX_VERSION (((UCX_VERSION_MAJOR)<<16)|UCX_VERSION_MINOR)
-// Common Includes
+// ---------------------------------------------------------------------------
+//       Common includes
+// ---------------------------------------------------------------------------
 #include <stdlib.h>
 #include <stddef.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <sys/types.h>
-#ifndef UCX_TEST_H
+// ---------------------------------------------------------------------------
+//       Architecture Detection
+// ---------------------------------------------------------------------------
+#ifndef INTPTR_MAX
+#error Missing INTPTR_MAX definition
+#endif
+#if INTPTR_MAX == INT64_MAX
+/**
+* The address width in bits on this platform.
+*/
+#define CX_WORDSIZE 64
+#elif INTPTR_MAX == INT32_MAX
+/**
+* The address width in bits on this platform.
+*/
+#define CX_WORDSIZE 32
+#else
+#error Unknown pointer size or missing size macros!
+#endif
+// ---------------------------------------------------------------------------
+//       Missing Defines
+// ---------------------------------------------------------------------------
+#ifndef SSIZE_MAX // not defined in glibc since C23 and MSVC
+#if CX_WORDSIZE == 64
+/**
+* The maximum representable value in ssize_t.
+*/
+#define SSIZE_MAX 0x7fffffffffffffffll
+#else
+#define SSIZE_MAX 0x7fffffffl
+#endif
+#endif
+// ---------------------------------------------------------------------------
+//       Attribute definitions
+// ---------------------------------------------------------------------------
+#ifndef __GNUC__
+/**
+* Removes GNU C attributes where they are not supported.
+*/
+#define __attribute__(x)
+#endif
+/**
+* All pointer arguments must be non-NULL.
+*/
+#define cx_attr_nonnull __attribute__((__nonnull__))
+/**
+* The specified pointer arguments must be non-NULL.
+*/
+#define cx_attr_nonnull_arg(...) __attribute__((__nonnull__(__VA_ARGS__)))
+/**
+* The returned value is guaranteed to be non-NULL.
+*/
+#define cx_attr_returns_nonnull __attribute__((__returns_nonnull__))
+/**
+* The attributed function always returns freshly allocated memory.
+*/
+#define cx_attr_malloc __attribute__((__malloc__))
+#ifndef __clang__
+/**
+* The pointer returned by the attributed function is supposed to be freed
+* by @p freefunc.
+*
+* @param freefunc the function that shall be used to free the memory
+* @param freefunc_arg the index of the pointer argument in @p freefunc
+*/
+#define cx_attr_dealloc(freefunc, freefunc_arg) \
+__attribute__((__malloc__(freefunc, freefunc_arg)))
+#else
+/**
+* Not supported in clang.
+*/
+#define cx_attr_dealloc(...)
+#endif // __clang__
+/**
+* Shortcut to specify #cxFree() as deallocator.
+*/
+#define cx_attr_dealloc_ucx cx_attr_dealloc(cxFree, 2)
+/**
+* Specifies the parameters from which the allocation size is calculated.
+*/
+#define cx_attr_allocsize(...) __attribute__((__alloc_size__(__VA_ARGS__)))
+#ifdef __clang__
+/**
+* No support for @c null_terminated_string_arg in clang or GCC below 14.
+*/
+#define cx_attr_cstr_arg(idx)
+/**
+* No support for access attribute in clang.
+*/
+#define cx_attr_access(mode, ...)
+#else
+#if __GNUC__ < 10
+/**
+* No support for access attribute in GCC < 10.
+*/
+#define cx_attr_access(mode, ...)
+#else
+/**
+* Helper macro to define access macros.
+*/
+#define cx_attr_access(mode, ...) __attribute__((__access__(mode, __VA_ARGS__)))
+#endif // __GNUC__ < 10
+#if __GNUC__ < 14
+/**
+* No support for @c null_terminated_string_arg in clang or GCC below 14.
+*/
+#define cx_attr_cstr_arg(idx)
+#else
+/**
+* The specified argument is expected to be a zero-terminated string.
+*
+* @param idx the index of the argument
+*/
+#define cx_attr_cstr_arg(idx) \
+__attribute__((__null_terminated_string_arg__(idx)))
+#endif // __GNUC__ < 14
+#endif // __clang__
+/**
+* Specifies that the function will only read through the given pointer.
+*
+* Takes one or two arguments: the index of the pointer and (optionally) the
+* index of another argument specifying the maximum number of accessed bytes.
+*/
+#define cx_attr_access_r(...) cx_attr_access(__read_only__, __VA_ARGS__)
+/**
+* Specifies that the function will read and write through the given pointer.
+*
+* Takes one or two arguments: the index of the pointer and (optionally) the
+* index of another argument specifying the maximum number of accessed bytes.
+*/
+#define cx_attr_access_rw(...) cx_attr_access(__read_write__, __VA_ARGS__)
+/**
+* Specifies that the function will only write through the given pointer.
+*
+* Takes one or two arguments: the index of the pointer and (optionally) the
+* index of another argument specifying the maximum number of accessed bytes.
+*/
+#define cx_attr_access_w(...) cx_attr_access(__write_only__, __VA_ARGS__)
+#if __STDC_VERSION__ >= 202300L
+/**
+* Do not warn about unused variable.
+*/
+#define cx_attr_unused [[maybe_unused]]
+/**
+* Warn about discarded return value.
+*/
+#define cx_attr_nodiscard [[nodiscard]]
+#else // no C23
+/**
+* Do not warn about unused variable.
+*/
+#define cx_attr_unused __attribute__((__unused__))
+/**
+* Warn about discarded return value.
+*/
+#define cx_attr_nodiscard __attribute__((__warn_unused_result__))
+#endif // __STDC_VERSION__
+// ---------------------------------------------------------------------------
+//       Useful function pointers
+// ---------------------------------------------------------------------------
 /**
 * Function pointer compatible with fwrite-like functions.
 */
 typedef size_t (*cx_write_func)(
-void const *,
+const void *,
 size_t,
 size_t,
 void *
 );
-#endif // UCX_TEST_H
 /**
 * Function pointer compatible with fread-like functions.
 */
 typedef size_t (*cx_read_func)(
 size_t,
 size_t,
 void *
 );
+// ---------------------------------------------------------------------------
-// Compiler specific stuff
+//       Utility macros
+// ---------------------------------------------------------------------------
-#ifndef __GNUC__
 /**
-* Removes GNU C attributes where they are not supported.
+* Determines the number of members in a static C array.
-*/
+*
-#define __attribute__(x)
+* @attention never use this to determine the size of a dynamically allocated
-#endif
+* array.
+*
+* @param arr the array identifier
+* @return the number of elements
+*/
+#define cx_nmemb(arr) (sizeof(arr)/sizeof((arr)[0]))
+// ---------------------------------------------------------------------------
+//       szmul implementation
+// ---------------------------------------------------------------------------
+#if (__GNUC__ >= 5 || defined(__clang__)) && !defined(CX_NO_SZMUL_BUILTIN)
+#define CX_SZMUL_BUILTIN
+#define cx_szmul(a, b, result) __builtin_mul_overflow(a, b, result)
+#else // no GNUC or clang bultin
+/**
+* Performs a multiplication of size_t values and checks for overflow.
+*
+* @param a (@c size_t) first operand
+* @param b (@c size_t) second operand
+* @param result (@c size_t*) a pointer to a variable, where the result should
+* be stored
+* @retval zero success
+* @retval non-zero the multiplication would overflow
+*/
+#define cx_szmul(a, b, result) cx_szmul_impl(a, b, result)
+/**
+* Implementation of cx_szmul() when no compiler builtin is available.
+*
+* Do not use in application code.
+*
+* @param a first operand
+* @param b second operand
+* @param result a pointer to a variable, where the result should
+* be stored
+* @retval zero success
+* @retval non-zero the multiplication would overflow
+*/
+#if __cplusplus
+extern "C"
+#endif
+int cx_szmul_impl(size_t a, size_t b, size_t *result);
+#endif // cx_szmul
+// ---------------------------------------------------------------------------
+//       Fixes for MSVC incompatibilities
+// ---------------------------------------------------------------------------
 #ifdef _MSC_VER
 // fix missing ssize_t definition
 #include <BaseTsd.h>
 typedef SSIZE_T ssize_t;
 // fix missing _Thread_local support
 #define _Thread_local __declspec(thread)
+#endif // _MSC_VER
-#endif
 #endif // UCX_COMMON_H

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comparison: ucx/cx/common.h

ucx/cx/common.h