added stpncpy

Author: ZERICO2005

src/libc/stpncpy.src

@@ -0,0 +1,57 @@
+	assume	adl=1
+
+	section	.text
+
+	public	_stpncpy
+
+_stpncpy:
+	ld	iy, 0
+	add	iy, sp
+	ld	bc, (iy + 9)	; max_len
+
+	; inlined strnlen
+	xor	a, a
+	sbc	hl, hl
+	sbc	hl, bc
+	jr	z, .zero_size
+	add	hl, bc
+	ld	de, (iy + 6)	; src
+	sbc	hl, de
+	ex	de, hl
+	cpir
+	jr	z, .finish_strnlen
+	inc	hl
+.finish_strnlen:
+	xor	a, a
+	adc	hl, de
+.zero_size:
+
+	; copy strnlen bytes from src
+	push	hl
+	ld	de, (iy + 3)	; dst
+	jr	z, .zero_byte_copy
+	ld	hl, (iy + 6)	; src
+	pop	bc
+	push	bc
+	ldir
+.zero_byte_copy:
+	pop	bc
+
+	; zero pad the remainder
+	ld	hl, (iy + 9)	; max_len
+	scf
+	sbc	hl, bc		; clear_size - 1 = max_len - src_len - 1
+	ex	de, hl
+	ret	c		; clear_size <= 0 (or max_len <= src_len)
+	; HL = dst + src_len
+	; DE = clear_size - 1
+	add	hl, de
+	ld	(hl), a
+	ret	z		; clear_size == 1
+	push	de
+	pop	bc
+	push	hl
+	pop	de
+	dec	de
+	lddr
+	ret

test/standalone/asprintf_fprintf/src/main.c

@@ -56,6 +56,9 @@ void *T_memrchr(const void *s, int c, size_t n)
 char *T_stpcpy(char *__restrict dest, const char *__restrict src)
     __attribute__((nonnull(1, 2)));
 
+char *T_stpncpy(char *__restrict dest, const char *__restrict src, size_t n)
+    __attribute__((nonnull(1, 2)));
+
 size_t T_strlcat(void *__restrict dest, const void *__restrict src, size_t n)
     __attribute__((nonnull(1, 2)));
 
@@ -80,6 +83,7 @@ void T_bzero(void* s, size_t n);
 #define T_mempcpy mempcpy
 #define T_memrchr memrchr
 #define T_stpcpy stpcpy
+#define T_stpncpy stpncpy
 #define T_strlcat strlcat
 #define T_strlen strlen
 #define T_strcmp strcmp
@@ -653,6 +657,49 @@ int strlcat_test(void) {
     return 0;
 }
 
+int stpncpy_test(void) {
+    char text[6];
+
+    C(T_stpncpy(NULL_ptr, "", 0) == NULL_ptr + 0);
+    C(T_stpncpy(NULL_ptr, "foobar", 0) == NULL_ptr + 0);
+
+    memset(text, '\xee', 6);
+
+    C(T_stpncpy(text, "1", 5) == text + 1);
+    C(memcmp(text, "1\0\0\0\0\xee", 6) == 0);
+
+    C(T_stpncpy(text, "1234", 5) == text + 4);
+    C(memcmp(text, "1234\0\xee", 6) == 0);
+
+    C(T_stpncpy(text, "12345", 5) == text + 5);
+    C(memcmp(text, "12345\xee", 6) == 0);
+
+    C(T_stpncpy(text, "123456", 5) == text + 5);
+    C(memcmp(text, "12345\xee", 6) == 0);
+
+    memset(text, '\xff', 6);
+
+    C(T_stpncpy(text, "", 0) == text + 0);
+    C(memcmp(text, "\xff\xff\xff\xff\xff\xff", 6) == 0);
+
+    C(T_stpncpy(text, "123456", 1) == text + 1);
+    C(memcmp(text, "1\xff\xff\xff\xff\xff", 1) == 0);
+
+    C(T_stpncpy(text, "6", 1) == text + 1);
+    C(memcmp(text, "6\xff\xff\xff\xff\xff", 1) == 0);
+
+    C(T_stpncpy(text, "", 1) == text + 0);
+    C(memcmp(text, "\0\xff\xff\xff\xff\xff", 1) == 0);
+
+    C(T_stpncpy(text, "a", 2) == text + 1);
+    C(memcmp(text, "a\0\xff\xff\xff\xff", 1) == 0);
+
+    C(T_stpncpy(text, "", 5) == text + 0);
+    C(memcmp(text, "\0\0\0\0\0\xff", 1) == 0);
+
+    return 0;
+}
+
 int run_tests(void) {
     int ret = 0;
     /* boot_asprintf */
@@ -680,6 +727,7 @@ int run_tests(void) {
     TEST(memrchr_test());
     TEST(memmove_test());
     TEST(strlcat_test());
+    TEST(stpncpy_test());
 
     return 0;
 }

test/standalone/asprintf_fprintf/src/rename.asm

@@ -3,7 +3,7 @@
 	section	.text
 
 	public	_T_memset, _T_memcpy, _T_memmove, _T_memcmp, _T_memccpy, _T_mempcpy, _T_memrchr
-	public	_T_strlen, _T_strcmp, _T_strncmp, _T_stpcpy, _T_strlcat
+	public	_T_strlen, _T_strcmp, _T_strncmp, _T_stpcpy, _T_stpncpy, _T_strlcat
 	public	_T_bzero
 
 _T_memset := _memset
@@ -18,6 +18,7 @@ _T_strlen := _strlen
 _T_strcmp := _strcmp
 _T_strncmp := _strncmp
 _T_stpcpy := _stpcpy
+_T_stpncpy := _stpncpy
 _T_strlcat := _strlcat
 
 _T_bzero := _bzero
@@ -29,5 +30,5 @@ _NULL_ptr:
 	db	$00, $00, $00
 
 	extern	_memset, _memcpy, _memmove, _memcmp, _memccpy, _mempcpy, _memrchr
-	extern	_strlen, _strcmp, _strncmp, _stpcpy, _strlcat
+	extern	_strlen, _strcmp, _strncmp, _stpcpy, _stpncpy, _strlcat
 	extern	_bzero