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-rw-r--r--include/stdio.h85
1 files changed, 84 insertions, 1 deletions
diff --git a/include/stdio.h b/include/stdio.h
index 4dc0e18..2b63ded 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -216,6 +216,48 @@ int asprintf(char** restrict, const char* restrict, ...)
#endif
#if defined(__SLIBC_SOURCE)
+# if defined(__GNUC__)
+/**
+ * This function is identical to `sprintf`,
+ * except it allocates a sufficiently large
+ * buffer to the stack (using `alloca`.)
+ *
+ * This is a slibc extension. It is only available
+ * if compiling with GCC.
+ *
+ * There is no `vasprintfa` function.
+ *
+ * @param buffer:char** Output parameter for the output buffer,
+ * must not be `NULL`. On error the content
+ * of this pointer is either `NULL` or a
+ * pointer to memory allocated with `alloca`.
+ * @param format:char* The formatting-string, must not have
+ * side-effects or be `NULL`.
+ * @param ... The formatting-arguments, must not have
+ * side-effects.
+ * @return :int The number of written bytes, excluding
+ * the NUL byte. On error, a negative value
+ * (namely -1 in this implementation) is
+ * returned. It is unspecified what shall
+ * happen if more than `INT_MAX` non-NUL
+ * bytes are written; in slibc, `INT_MAX`
+ * is returned if more is written, you can
+ * use "%zn" to find the actual length.
+ *
+ * @throws EINVAL `format` contained unsupported formatting codes.
+ */
+int asprintfa(buffer, format, ...) \
+ ({ \
+ ssize_t __size; \
+ int __r; \
+ __r = snprintf(NULL, 0, format "%zn", ##__VA_ARGS__, &__size); \
+ if (*buffer = NULL, __size += 1, __r >= 0) \
+ *buffer = __builtin_alloca((size_t)__size * sizeof(char)), \
+ __r = sprintf(*buffer, format, ##__VA_ARGS__); \
+ __r; \
+ })
+# endif
+
/**
* This function is identical to `asprintf`,
* except it can reuse allocated buffers.
@@ -620,7 +662,48 @@ int aswprintf(wchar_t** restrict, const wchar_t* restrict, ...)
__GCC_ONLY(__attribute__((__nonnull__(1, 2), __warn_unused_result__)));
# endif
-# if defined(__SLIBC_SOURCE)
+# if defined(__SLIBC_SOURCE)# if defined(__GNUC__)
+/**
+ * This function is identical to `swprintf`,
+ * except it allocates a sufficiently large
+ * buffer to the stack (using `alloca`.)
+ *
+ * This is a slibc extension. It is only available
+ * if compiling with GCC.
+ *
+ * There is no `vaswprintfa` function.
+ *
+ * @param buffer:char** Output parameter for the output buffer,
+ * must not be `NULL`. On error the content
+ * of this pointer is either `NULL` or a
+ * pointer to memory allocated with `alloca`.
+ * @param format:char* The formatting-string, must not have
+ * side-effects or be `NULL`.
+ * @param ... The formatting-arguments, must not have
+ * side-effects.
+ * @return :int The number of written bytes, excluding
+ * the NUL byte. On error, a negative value
+ * (namely -1 in this implementation) is
+ * returned. It is unspecified what shall
+ * happen if more than `INT_MAX` non-NUL
+ * bytes are written; in slibc, `INT_MAX`
+ * is returned if more is written, you can
+ * use "%zn" to find the actual length.
+ *
+ * @throws EINVAL `format` contained unsupported formatting codes.
+ */
+int aswprintfa(buffer, format, ...) \
+ ({ \
+ ssize_t __size; \
+ int __r; \
+ __r = swprintf(NULL, 0, format "%zn", ##__VA_ARGS__, &__size); \
+ if (*buffer = NULL, __size += 1, __r >= 0) \
+ *buffer = __builtin_alloca((size_t)__size * sizeof(wchar_t)), \
+ __r = swprintf(*buffer, (size_t)__size, format, ##__VA_ARGS__); \
+ __r; \
+ })
+# endif
+
/**
* This function is identical to `bprintf` except
* it uses wide characters.