diff --git a/code/assert.c b/code/assert.c
index 146e326..cd95f43 100644
--- a/code/assert.c
+++ b/code/assert.c
@@ -3,6 +3,14 @@
 #include <stdlib.h>
 #include <_platform.h>
 
+// TODO: use abort() to break
+#if defined(_compiler_msvc)
+    #include <intrin.h>
+    #define brk __debugbreak
+#else
+    #define brk __builtin_trap
+#endif
+
 #if defined(_os_win)
     #define WIN32_LEAN_AND_MEAN
     #include<Windows.h>
@@ -22,7 +30,7 @@
         WriteConsole(conout, str, _assert_strlen(str), &written, NULL);
     }
 
-    extern void _assert_print(char *cond, char const *func, char const *file, char const *line)
+    extern void _assert_error(char *cond, char const *func, char const *file, char const *line)
     {
         HANDLE conout = GetStdHandle(STD_OUTPUT_HANDLE);
         if(conout != INVALID_HANDLE_VALUE) {
@@ -42,5 +50,6 @@
                 "Error",
                 MB_OK);
         }
+        brk();
     }
 #endif
\ No newline at end of file
diff --git a/code/ctype.c b/code/ctype.c
new file mode 100644
index 0000000..1d8bffe
--- /dev/null
+++ b/code/ctype.c
@@ -0,0 +1,92 @@
+
+// TODO: table-driven?
+// TODO: other locales
+
+#include <ctype.h>
+#include <locale.h>
+
+#define in_range(low, v, high) ((low <= v) && (v <= high))
+
+int isalnum(int c)
+{
+    return isalpha(c) || isdigit(c);
+}
+
+int isalpha(int c)
+{
+    return islower(c) || isupper(c);
+}
+
+int isblank(int c)
+{
+    return c == ' ' || c == '\t';
+}
+
+int iscntrl(int c)
+{
+    return in_range('\x00', c, '\x1f') || c == '\x7f';
+}
+
+int isdigit(int c)
+{
+    return in_range('0', c, '9');
+}
+
+int isgraph(int c)
+{
+    return isprint(c) && (c != ' ');
+}
+
+int islower(int c)
+{
+    return in_range('a', c, 'z');
+}
+
+int isprint(int c)
+{
+    return in_range(' ', c, '\x7e');
+}
+
+int ispunct(int c)
+{
+    return in_range('\x21', c, '\x2f')
+        || in_range('\x3a', c, '\x40')
+        || in_range('\x5b', c, '\x60')
+        || in_range('\x7b', c, '\x7e');
+}
+
+int isspace(int c)
+{
+    return in_range('\x09', c, '\x0d')
+        || c == ' ';
+}
+
+int isupper(int c)
+{
+    return in_range('A', c, 'Z');
+}
+
+int isxdigit(int c)
+{
+    return in_range('0', c, '9')
+        || in_range('a', c, 'f')
+        || in_range('A', c, 'F');
+}
+
+int tolower(int c)
+{
+    if(isupper(c)) {
+        return c-'A'+'a';
+    }
+    else return c;
+}
+
+int toupper(int c)
+{
+    if(islower(c)) {
+        return c-'a'+'A';
+    }
+    else return c;
+}
+
+
diff --git a/code/entry_windows.c b/code/entry_windows.c
index a457d5c..7de915f 100644
--- a/code/entry_windows.c
+++ b/code/entry_windows.c
@@ -1,3 +1,4 @@
+
 #include <_platform.h>
 #include <locale.h>
 
diff --git a/inc/_macros.h b/inc/_macros.h
new file mode 100644
index 0000000..dc9df71
--- /dev/null
+++ b/inc/_macros.h
@@ -0,0 +1,13 @@
+
+#pragma once
+
+#define _str_(x) #x
+#define _str(x) _str_(x)
+
+#if !defined(_func)
+    #if defined(_compiler_msvc)
+        #define _func __FUNCTION__
+    #else
+        #define _func __func__
+    #endif
+#endif
diff --git a/inc/_platform.h b/inc/_platform.h
index 208cf68..ad2ab2a 100644
--- a/inc/_platform.h
+++ b/inc/_platform.h
@@ -32,14 +32,6 @@
     #error "Unsupported Compiler"
 #endif
 
-#if !defined(_func)
-    #if defined(_compiler_msvc)
-        #define _func __FUNCTION__
-    #else
-        #define _func __func__
-    #endif
-#endif
-
 // OS Identification
 
 #if defined(_WIN32)
@@ -58,4 +50,4 @@
 #ifdef __STDC_WANT_LIB_EXT1__
 	typedef int errno_t;
 	typedef size_t rsize_t;
-#endif
\ No newline at end of file
+#endif
diff --git a/inc/assert.h b/inc/assert.h
index 11f2361..c519463 100644
--- a/inc/assert.h
+++ b/inc/assert.h
@@ -1,20 +1,9 @@
-#if !defined(_assert_h)
-#define _assert_h
 
-#include "_platform.h"
+#pragma once
 
-extern void _assert_print(char *cond, char const *func, char const *file, char const *line);
+#include "_macros.h"
 
-// TODO: use abort() to break
-#if defined(_compiler_msvc)
-    #include <intrin.h>
-    #define _compiler_brk __debugbreak
-#else
-    #define _compiler_brk __builtin_trap
-#endif
-
-#define _str_(x) #x
-#define _str(x) _str_(x)
+extern void _assert_error(char *cond, char const *func, char const *file, char const *line);
 
 #if defined(NDEBUG)
     #define assert(ignore) ((void)0)
@@ -23,10 +12,7 @@ extern void _assert_print(char *cond, char const *func, char const *file, char c
     #define assert(condition)                                                 \
         do {                                                                  \
             if(!(condition)) {                                                \
-                _assert_print(#condition, _func, __FILE__, _str(__LINE__));   \
-                _compiler_brk();                                              \
+                _assert_error(#condition, _func, __FILE__, _str(__LINE__));   \
             }                                                                 \
         } while(0)
 #endif
-
-#endif
\ No newline at end of file
diff --git a/inc/errno.h b/inc/errno.h
index bc9ca5b..a294129 100644
--- a/inc/errno.h
+++ b/inc/errno.h
@@ -4,5 +4,5 @@
 #define EILSEQ 2
 #define ERANGE 3
 
-// TODO: implement this
-#define errno 0
+// TODO:
+//_Thread_local int errno;
diff --git a/inc/stdlib.h b/inc/stdlib.h
index ae32cea..9f4bb3b 100644
--- a/inc/stdlib.h
+++ b/inc/stdlib.h
@@ -1,71 +1,71 @@
 #include "_platform.h"
 
-typedef struct div_t {
-    int quot;
-    int rem;
-} div_t;
+// typedef struct div_t {
+//     int quot;
+//     int rem;
+// } div_t;
 
-typedef struct ldiv_t {
-    long quot;
-    long rem;
-} ldiv_t;
+// typedef struct ldiv_t {
+//     long quot;
+//     long rem;
+// } ldiv_t;
 
-typedef struct lldiv_t {
-    long long quot;
-    long long rem;
-} lldiv_t;
+// typedef struct lldiv_t {
+//     long long quot;
+//     long long rem;
+// } lldiv_t;
 
-#define EXIT_FAILURE 1
-#define EXIT_SUCCESS 0
+// #define EXIT_FAILURE 1
+// #define EXIT_SUCCESS 0
 
-#define RAND_MAX 65536
-#define MB_CUR_MAX 5
+// #define RAND_MAX 65536
+// #define MB_CUR_MAX 5
 	
-double atof(const char *nptr);
-int atoi(const char *nptr);
-long int atol(const char *nptr);
-long long int atoll(const char *nptr);
-double strtod(const char * restrict nptr, char ** restrict endptr);
-float strtof(const char * restrict nptr, char ** restrict endptr);
-long double strtold(const char * restrict nptr, char ** restrict endptr);
-long int strtol(const char * restrict nptr, char ** restrict endptr, int base);
-long long int strtoll(const char * restrict nptr, char ** restrict endptr, int base);
-unsigned long int strtoul(const char * restrict nptr, char ** restrict endptr, int base);
-unsigned long long int strtoull(const char * restrict nptr, char ** restrict endptr, int base);
-int rand(void);
-void srand(unsigned int seed);
-void *aligned_alloc(size_t alignment, size_t size);
-void *calloc(size_t nmemb, size_t size);
-void free(void *ptr);
-void *malloc(size_t size);
-void *realloc(void *ptr, size_t size);
-_Noreturn void abort(void);
-int atexit(void (*func)(void));
-int at_quick_exit(void (*func)(void));
-_Noreturn void exit(int status);
-_Noreturn void _Exit(int status);
-char *getenv(const char *name);
-_Noreturn void quick_exit(int status);
-int system(const char *string);
-void *bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
-void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
-int abs(int j);
-long int labs(long int j);
-long long int llabs(long long int j);
-div_t div(int numer, int denom);
-ldiv_t ldiv(long int numer, long int denom);
-lldiv_t lldiv(long long int numer, long long int denom);
-int mblen(const char *s, size_t n);
-int mbtowc(wchar_t * restrict pwc, const char * restrict s, size_t n);
-int wctomb(char *s, wchar_t wchar);
-size_t mbstowcs(wchar_t * restrict pwcs, const char * restrict s, size_t n);
-size_t wcstombs(char * restrict s, const wchar_t * restrict pwcs, size_t n);
+// double atof(const char *nptr);
+// int atoi(const char *nptr);
+// long int atol(const char *nptr);
+// long long int atoll(const char *nptr);
+// double strtod(const char * restrict nptr, char ** restrict endptr);
+// float strtof(const char * restrict nptr, char ** restrict endptr);
+// long double strtold(const char * restrict nptr, char ** restrict endptr);
+// long int strtol(const char * restrict nptr, char ** restrict endptr, int base);
+// long long int strtoll(const char * restrict nptr, char ** restrict endptr, int base);
+// unsigned long int strtoul(const char * restrict nptr, char ** restrict endptr, int base);
+// unsigned long long int strtoull(const char * restrict nptr, char ** restrict endptr, int base);
+// int rand(void);
+// void srand(unsigned int seed);
+// void *aligned_alloc(size_t alignment, size_t size);
+// void *calloc(size_t nmemb, size_t size);
+// void free(void *ptr);
+// void *malloc(size_t size);
+// void *realloc(void *ptr, size_t size);
+// _Noreturn void abort(void);
+// int atexit(void (*func)(void));
+// int at_quick_exit(void (*func)(void));
+// _Noreturn void exit(int status);
+// _Noreturn void _Exit(int status);
+// char *getenv(const char *name);
+// _Noreturn void quick_exit(int status);
+// int system(const char *string);
+// void *bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
+// void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *));
+// int abs(int j);
+// long int labs(long int j);
+// long long int llabs(long long int j);
+// div_t div(int numer, int denom);
+// ldiv_t ldiv(long int numer, long int denom);
+// lldiv_t lldiv(long long int numer, long long int denom);
+// int mblen(const char *s, size_t n);
+// int mbtowc(wchar_t * restrict pwc, const char * restrict s, size_t n);
+// int wctomb(char *s, wchar_t wchar);
+// size_t mbstowcs(wchar_t * restrict pwcs, const char * restrict s, size_t n);
+// size_t wcstombs(char * restrict s, const wchar_t * restrict pwcs, size_t n);
 
-#ifdef __STDC_WANT_LIB_EXT1__
-	typedef void (*constraint_handler_t)(const char * restrict msg, void * restrict ptr, errno_t error);
+// #ifdef __STDC_WANT_LIB_EXT1__
+// 	typedef void (*constraint_handler_t)(const char * restrict msg, void * restrict ptr, errno_t error);
 	
-	constraint_handler_t set_constraint_handler_s(constraint_handler_t handler);
-	void abort_handler_s(const char * restrict msg, void * restrict ptr, errno_t error);
-	void ignore_handler_s(const char * restrict msg, void * restrict ptr, errno_t error);
-	errno_t getenv_s(size_t * restrict len, char * restrict value, rsize_t maxsize, const char * restrict name);
-#endif
+// 	constraint_handler_t set_constraint_handler_s(constraint_handler_t handler);
+// 	void abort_handler_s(const char * restrict msg, void * restrict ptr, errno_t error);
+// 	void ignore_handler_s(const char * restrict msg, void * restrict ptr, errno_t error);
+// 	errno_t getenv_s(size_t * restrict len, char * restrict value, rsize_t maxsize, const char * restrict name);
+// #endif
diff --git a/inc/string.h b/inc/string.h
index 45b2c87..201bc70 100644
--- a/inc/string.h
+++ b/inc/string.h
@@ -1,5 +1,7 @@
 #include "_platform.h"
 
+int _wcsicmp(const wchar_t *string1, const wchar_t *string2);
+
 void *memcpy(void * restrict s1, const void * restrict s2, size_t n);
 void *memmove(void *s1, const void *s2, size_t n);
 char *strcpy(char * restrict s1, const char * restrict s2);
diff --git a/makefile b/makefile
index 7429823..80f36ca 100644
--- a/makefile
+++ b/makefile
@@ -1,10 +1,10 @@
 
-GNUFLAGS=-g -gcodeview -Werror -Wall -Iinc -Icode
-CLFLAGS=/Zi /I:inc /link /incremental:no /subsystem:windows /nodefaultlib kernel32.lib
+# TODO: make shell variable-based path
+CLFLAGS=/X /GS- /Iinc /Icode $(shell test\inctoarg)
 
-CC=clang
-CFLAGS=$(GNUFLAGS)
-LDFLAGS=/nologo /nodefaultlib /entry:mainCRTStartup
+CC=clang-cl
+CFLAGS=$(CLFLAGS)
+LDFLAGS=/nologo /nodefaultlib /entry:mainCRTStartup /subsystem:console
 
 SRC_DIR := code
 OBJ_DIR := build
@@ -14,7 +14,14 @@ OBJ_FILES := $(patsubst $(SRC_DIR)/%.c,$(OBJ_DIR)/%.obj,$(SRC_FILES))
 ciabatta.lib: $(OBJ_FILES)
 	lib $(LDFLAGS) /out:$@ $^
 
-$(OBJ_DIR)/%.obj: $(SRC_DIR)/%.c
-	$(CC) $(CFLAGS) -c -o $@ $<
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
+	$(CC) -c -o $@ $< $(CFLAGS)
 
-.PHONY: ciabatta.lib
+clean:
+	del /F /Q build\*
+	del /F /Q lib\ciabatta.lib
+
+inctoarg:
+	cl test\inctoarg.c
+
+.PHONY: inctoarg ciabatta.lib