Merge 256bf21099 into acbab53d13

src/main/common/printf.c

@@ -46,6 +46,8 @@
 
 #ifdef REQUIRE_CC_ARM_PRINTF_SUPPORT
 
+#define DEFAULT_FLOAT_PRECISION 6
+
 putcf stdout_putf;
 void *stdout_putp;
 
@@ -68,10 +70,88 @@ static int putchw(void *putp, putcf putf, int n, char z, char *bf)
     return written;
 }
 
-// retrun number of bytes written
+// function to convert float to string
+static void tfp_ftoa(double f, char *buf, int buf_size, int precision) {
+    int i = 0;
+    const double scales[] = { 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6 };
+
+    // Handle negative numbers
+    if (f < 0) {
+        buf[i++] = '-';
+        f = -f;  // Make f positive
+    }
+
+    // Extract integer part
+    long int_part = (long)f;
+
+    // Extract fractional part
+    double frac_part = f - (double)int_part;
+
+    // Scale the fractional part for rounding
+    double scaled_frac_part = frac_part * scales[precision];
+
+    // Get the rounded fractional part
+    long rounded_frac = (long)(scaled_frac_part);
+    double last_digit = scaled_frac_part - rounded_frac; // Get last digit for rounding
+
+    // Handle rounding based on the last digit
+    if (last_digit >= (double)0.5) {
+        rounded_frac++;  // Round up if the last digit is 5 or more
+    }
+
+    // Check for overflow in the fractional part
+    if (rounded_frac >= scales[precision]) {
+        rounded_frac = 0;
+        int_part++;  // Increment the integer part if necessary
+    }
+
+    // Convert the integer part to string
+    if (int_part == 0) {
+        buf[i++] = '0';
+    } else {
+        long num = int_part;
+        int digits = 0;
+
+        // Calculate the number of digits in the integer part
+        long temp = num;
+        while (temp > 0) {
+            temp /= 10;
+            digits++;
+        }
+
+        // Write digits starting from the highest digit
+        for (int j = digits - 1; j >= 0; j--) {
+            if (i < buf_size - 1) {
+                buf[i + j] = (num % 10) + '0';
+                num /= 10;
+            }
+        }
+        i += digits;
+    }
+
+    // Add decimal point and fractional part if precision > 0
+    if (precision > 0 && i < buf_size - 1) {
+        buf[i++] = '.';
+
+        // Convert the fractional part to string
+        for (int j = 0; j < precision && i < buf_size - 1; j++) {
+            rounded_frac *= 10;  // Shift left
+            buf[i++] = (char)(rounded_frac / scales[precision]) + '0';
+            rounded_frac %= (long)scales[precision];
+        }
+    }
+
+    if (i < buf_size) {
+        buf[i] = '\0';
+    } else {
+        buf[buf_size - 1] = '\0';
+    }
+}
+
+// return number of bytes written
 int tfp_format(void *putp, putcf putf, const char *fmt, va_list va)
 {
-    char bf[12];
+    char bf[32];
     int written = 0;
     char ch;
 
@@ -84,6 +164,7 @@ int tfp_format(void *putp, putcf putf, const char *fmt, va_list va)
             char lng = 0;
 #endif
             int w = 0;
+            int precision = DEFAULT_FLOAT_PRECISION; // Default float precision
             ch = *(fmt++);
             if (ch == '0') {
                 ch = *(fmt++);
@@ -92,6 +173,12 @@ int tfp_format(void *putp, putcf putf, const char *fmt, va_list va)
             if (ch >= '0' && ch <= '9') {
                 ch = a2i(ch, &fmt, 10, &w);
             }
+            if (ch == '.') {
+                ch = *(fmt++);
+                if (ch >= '0' && ch <= '9') {
+                    ch = a2i(ch, &fmt, 10, &precision);
+                }
+            }
 #ifdef  REQUIRE_PRINTF_LONG_SUPPORT
             if (ch == 'l') {
                 ch = *(fmt++);
@@ -143,6 +230,13 @@ int tfp_format(void *putp, putcf putf, const char *fmt, va_list va)
             case 'n':
                 *va_arg(va, int*) = written;
                 break;
+            case 'f': {
+                double f = va_arg(va, double);
+                if (precision > DEFAULT_FLOAT_PRECISION) precision = DEFAULT_FLOAT_PRECISION;
+                tfp_ftoa(f, bf, sizeof(bf) - 1, precision);
+                written = putchw(putp, putf, w, lz, bf);
+                break;
+            }
             default:
                 break;
             }