Implemented strlcat and stpncpy

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

src/libc/strlcat.src

@@ -0,0 +1,76 @@
+	assume	adl=1
+
+	section	.text
+
+	public	_strlcat
+
+_strlcat:
+	ld	iy, 0
+	lea	bc, iy
+	add	iy, sp
+	ld	hl, (iy + 6)	; src
+	xor	a, a
+	cpir
+	sbc	hl, hl
+	dec	hl
+	sbc	hl, bc
+	; carry is clear
+	ex	de, hl
+
+	; inlined strnlen
+	ld	bc, (iy + 9)	; max_size
+	sbc	hl, hl
+	sbc	hl, bc
+	; Allows dst to be NULL when max_size is zero
+	jr	z, .zero_size	; return src_len
+	add	hl, bc
+	push	de		; src_len
+	ld	de, (iy + 3)	; dst
+	sbc	hl, de
+	ex	de, hl
+	cpir
+	add	hl, de
+	jr	z, .finish_strnlen
+	inc	hl
+.finish_strnlen:
+
+	ex	de, hl
+	ld	hl, (iy + 9)	; max_size
+	; (copy_size + 1) = max_size - dst_len
+	xor	a, a
+	sbc	hl, de
+	jr	z, .no_room
+
+	pop	bc		; src_len
+	push	bc
+
+	; (copy_size + 1) - src_len - 1
+	scf
+	sbc	hl, bc
+
+	jr	c, .copy_size_lt_src_len
+	; (copy_size + 1 - 1) >= src_len
+	; copy_size >= src_len
+	sbc	hl, hl
+.copy_size_lt_src_len:
+	xor	a, a
+	adc	hl, bc
+	jr	z, .zero_copy_size
+	push	hl
+	pop	bc
+
+	push	de		; dst_len
+	ld	hl, (iy + 3)	; dst
+	add	hl, de		; dst + dst_len
+	ex	de, hl
+	ld	hl, (iy + 6)	; src
+	ldir
+	ld	(de), a		; null terminate
+	pop	de		; dst_len
+.zero_copy_size:
+.no_room:
+	pop	hl		; src_len
+.zero_size:
+	; return src_len + dst_len
+	add	hl, de
+	ret

test/standalone/asprintf_fprintf/src/main.c

@@ -22,6 +22,8 @@
 
 #define C(expr) if (!(expr)) { return __LINE__; }
 
+#define TEST(test) { ret = test; if (ret != 0) { return ret; }}
+
 #define SINK (char*)0xE40000
 
 /* pass NULL into functions without triggering -Wnonnull */
@@ -54,6 +56,12 @@ 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)));
+
 size_t T_strlen(const char *s)
     __attribute__((nonnull(1)));
 
@@ -75,6 +83,8 @@ 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
 #define T_strncmp strncmp
@@ -159,7 +169,7 @@ int boot_sprintf_tests(void) {
         printf("E: %d != %d\n", len_3, pos_3);
         return __LINE__;
     }
-    
+
     // large string test
     static char const * const s = "Hello";
     int len_4 = boot_snprintf(SINK, 300,
@@ -271,7 +281,7 @@ int nano_tests(void) {
         printf("E: %d != %d\n", len_3s, pos_3);
         return __LINE__;
     }
-    
+
     // https://en.cppreference.com/w/c/io/fprintf
     static char const * const s = "Hello";
     int len_4 = snprintf(SINK, 300,
@@ -360,7 +370,7 @@ int memccpy_tests(void) {
         return __LINE__;
     }
     file = fopen(file_name, "wb");
-    
+
     // Check if the file was opened successfully
     if (file == NULL) {
         perror("Error opening file");
@@ -371,32 +381,32 @@ int memccpy_tests(void) {
     const char terminal[] = {':', ' ', ',', '.', '!'};
     char dest[sizeof src];
     const char alt = '@';
- 
+
     for (size_t i = 0; i != sizeof terminal; ++i)
     {
         void* to = T_memccpy(dest, src, terminal[i], sizeof dest);
- 
+
         fprintf(file,"Terminal '%c' (%s):\t\"", terminal[i], to ? "found" : "absent");
- 
+
         // if `terminal` character was not found - print the whole `dest`
         to = to ? to : dest + sizeof dest;
- 
+
         for (char* from = dest; from != to; ++from) {
             fputc(isprint(*from) ? *from : alt, file);
         }
-        
+
         fputs("\"\n", file);
     }
- 
- 
+
+
     fprintf(file, "%c%s", '\n', "Separate star names from distances (ly):\n");
     const char *star_distance[] = {
         "Arcturus : 37", "Vega : 25", "Capella : 43", "Rigel : 860", "Procyon : 11"
     };
     char names_only[64];
     char *first = names_only;
     char *last = names_only + sizeof names_only;
- 
+
     for (size_t t = 0; t != (sizeof star_distance) / (sizeof star_distance[0]); ++t)
     {
         if (first) {
@@ -597,6 +607,99 @@ int memmove_test(void) {
     return 0;
 }
 
+static bool strcmp_exact(const char* x, const char* y) {
+    if (strlen(x) != strlen(y)) {
+        return false;
+    }
+    if (strcmp(x, y) != 0) {
+        return false;
+    }
+    return true;
+}
+
+int strlcat_test(void) {
+    const char* src1 = "Foo";
+    const char* src2 = "Bar";
+    char dst[10];
+
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 0) == 3); C(strcmp_exact(dst, "Foo"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 1) == 4); C(strcmp_exact(dst, "Foo"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 2) == 5); C(strcmp_exact(dst, "Foo"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 3) == 6); C(strcmp_exact(dst, "Foo"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 4) == 6); C(strcmp_exact(dst, "Foo"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 5) == 6); C(strcmp_exact(dst, "FooB"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 6) == 6); C(strcmp_exact(dst, "FooBa"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 7) == 6); C(strcmp_exact(dst, "FooBar"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 8) == 6); C(strcmp_exact(dst, "FooBar"));
+    strcpy(dst, src1); C(T_strlcat(dst , src2, 9) == 6); C(strcmp_exact(dst, "FooBar"));
+
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 0) == 0); C(strcmp_exact(dst, src1));
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 1) == 1); C(strcmp_exact(dst, src1));
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 2) == 2); C(strcmp_exact(dst, src1));
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 3) == 3); C(strcmp_exact(dst, src1));
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 4) == 3); C(strcmp_exact(dst, src1));
+    strcpy(dst, src1); C(T_strlcat(dst , SINK, 5) == 3); C(strcmp_exact(dst, src1));
+
+    C(T_strlcat(NULL_ptr, SINK, 0) == 0);
+    C(T_strlcat(NULL_ptr, src1, 0) == 3);
+
+    dst[0] = '\0'; C(T_strlcat(dst, SINK, 0) == 0); C(dst[0] == '\0');
+    dst[0] = '\0'; C(T_strlcat(dst, SINK, 1) == 0); C(dst[0] == '\0');
+    dst[0] = '\0'; C(T_strlcat(dst, SINK, 2) == 0); C(dst[0] == '\0');
+
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 0) == 3); C(strcmp_exact(dst, ""));
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 1) == 3); C(strcmp_exact(dst, ""));
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 2) == 3); C(strcmp_exact(dst, "F"));
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 3) == 3); C(strcmp_exact(dst, "Fo"));
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 4) == 3); C(strcmp_exact(dst, "Foo"));
+    dst[0] = '\0'; C(T_strlcat(dst, src1, 5) == 3); C(strcmp_exact(dst, "Foo"));
+
+    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 */
@@ -618,25 +721,13 @@ int run_tests(void) {
         }
         if (ret != 0) { return ret; }
 
-    /* mempcpy */
-        ret = mempcpy_test();
-        if (ret != 0) { return ret; }
-
-    /* bzero */
-        ret = bzero_test();
-        if (ret != 0) { return ret; }
-
-    /* strncmp */
-        ret = strncmp_test();
-        if (ret != 0) { return ret; }
-
-    /* memrchr */
-        ret = memrchr_test();
-        if (ret != 0) { return ret; }
-
-    /* memrchr */
-        ret = memmove_test();
-        if (ret != 0) { return ret; }
+    TEST(mempcpy_test());
+    TEST(bzero_test());
+    TEST(strncmp_test());
+    TEST(memrchr_test());
+    TEST(memmove_test());
+    TEST(strlcat_test());
+    TEST(stpncpy_test());
 
     return 0;
 }
@@ -675,7 +766,7 @@ int main(void)
             printf("All tests %s", "passed");
         #endif
     }
-    
+
     while (!os_GetCSC());
 
     return 0;