move abs() to stdlib.h where it is supposed to be

Author: twiddlingbits

source/twr-stdclib/include/math.h

@@ -5,7 +5,6 @@
 extern "C" {
 #endif
 
-int abs(int n);
 double acos(double arg);
 double asin(double arg);
 double atan(double arg);

source/twr-stdclib/include/stdlib.h

@@ -16,7 +16,6 @@ extern "C" {
 
 /************************/
 
-
 void *malloc(size_t size);
 void free(void *mem);
 size_t avail(void);
@@ -35,16 +34,20 @@ void srand(int seed);
 #define __min(a,b) (((a) < (b)) ? (a) : (b))
 #define __max(a,b) (((a) > (b)) ? (a) : (b))
 
+int abs(int n);
+
 /************************/
 
-int _fcvt_s(
+//The fcvt_s() function in C does not use locale information; it always uses . (a dot) as the decimal separator.
+__attribute__((import_name("twrFcvtS"))) int _fcvt_s(
    char* buffer,
-   size_t sizeInBytes,
+   unsigned long sizeInBytes,  //size_t 
    double value,
    int fracpart_numdigits,
    int *dec,
    int *sign
 );
+
 double atof(const char* str);
 int atoi(const char *str);
 long atol( const char *str );

source/twr-stdclib/math.c

@@ -1,10 +1,10 @@
 #include <math.h>
 #include "twr-jsimports.h"
 
-int abs(int n) {
-    if (n<0) return -n;
-    else return n;
-}
+// It is not possible to define the math library imports like this:
+// __attribute__((import_name("twrASin"))) double sin(double arg);
+// as the compiler optimizes math functions like sin, and even at -O0, ignores the custom math.h
+// using the clang flag -fno-builtin solves this issue, but doesn't seem like an optimizing solution
 
 double fabs (double arg) {
     return twrFAbs(arg);
@@ -99,9 +99,6 @@ int math_unit_test() {
 
    if (cos(0)!=1) return 0;
 
-   if (abs(5)!=5) return 0;
-   if (abs(-5)!=5) return 0;
-
    if (fabs(1.0)!=1.0) return 0;
    if (fabs(-1.0)!=1.0) return 0;
 

source/twr-stdclib/misc.c

@@ -2,14 +2,11 @@
 #include <string.h>
 #include <twr-crt.h>
 
-int misc_unit_test() {
-	if (__min(5, 100)!=5) return 0;
-	if (__max(5, 100)!=100) return 0;
-
-	return 1;
+int abs(int n) {
+    if (n<0) return -n;
+    else return n;
 }
 
-
 /**************************************************/
 
 // for internal use, not an export
@@ -23,6 +20,16 @@ void __nstrcopy(char *dest, const int sizeInBytes, const char *src, const int si
 	else if (sizeInBytes>0) dest[0]=0;
 }
 
+/**************************************************/
+
+int misc_unit_test() {
+	if (__min(5, 100)!=5) return 0;
+	if (__max(5, 100)!=100) return 0;
 
+   if (abs(5)!=5) return 0;
+   if (abs(-5)!=5) return 0;
+
+	return 1;
+}