restore dtostrf when floats are disabled in printf/scanf + round fix

cores/esp8266/core_esp8266_noniso.cpp

@@ -28,6 +28,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <math.h>
+#include <limits>
 #include "stdlib_noniso.h"
 
 extern "C" {
@@ -40,11 +41,94 @@ char* ultoa(unsigned long value, char* result, int base) {
     return utoa((unsigned int)value, result, base);
 }
 
+#ifdef NOPRINTFLOAT
+
+char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
+    bool negative = false;
+
+    if (isnan(number)) {
+        strcpy(s, "nan");
+        return s;
+    }
+    if (isinf(number)) {
+        strcpy(s, "inf");
+        return s;
+    }
+
+    char* out = s;
+
+    int fillme = width; // how many cells to fill for the integer part
+    if (prec > 0) {
+        fillme -= (prec+1);
+    }
+
+    // Handle negative numbers
+    if (number < 0.0) {
+        negative = true;
+        fillme--;
+        number = -number;
+    }
+
+    // Round correctly so that print(1.999, 2) prints as "2.00"
+    // I optimized out most of the divisions
+    double rounding = 2.0;
+    for (uint8_t i = 0; i < prec; ++i)
+        rounding *= 10.0;
+    rounding = 1.0 / rounding;
+
+    number += rounding;
+
+    // Figure out how big our number really is
+    double tenpow = 1.0;
+    int digitcount = 1;
+    double nextpow;
+    while (number >= (nextpow = (10.0 * tenpow))) {
+        tenpow = nextpow;
+        digitcount++;
+    }
+
+    // minimal compensation for possible lack of precision
+    number *= 1 + std::numeric_limits<decltype(number)>::epsilon();
+
+    number /= tenpow;
+    fillme -= digitcount;
+
+    // Pad unused cells with spaces
+    while (fillme-- > 0) {
+        *out++ = ' ';
+    }
+
+    // Handle negative sign
+    if (negative) *out++ = '-';
+
+    // Print the digits, and if necessary, the decimal point
+    digitcount += prec;
+    int8_t digit = 0;
+    while (digitcount-- > 0) {
+        digit = (int8_t)number;
+        if (digit > 9) digit = 9; // insurance
+        *out++ = (char)('0' | digit);
+        if ((digitcount == prec) && (prec > 0)) {
+            *out++ = '.';
+        }
+        number -= digit;
+        number *= 10.0;
+    }
+
+    // make sure the string is terminated
+    *out = 0;
+    return s;
+}
+
+#else // !NOPRINTFLOAT
+
 char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     char fmt[32];
     sprintf(fmt, "%%%d.%df", width, prec);
     sprintf(s, fmt, number);
     return s;
 }
 
+#endif // !NOPRINTFLOAT
+
 };

platform.txt

@@ -38,6 +38,7 @@ build.stdcpp_lib=-lstdc++
 build.stdcpp_level=-std=gnu++11
 
 build.float=-u _printf_float -u _scanf_float
+build.floatflags=
 build.led=
 
 # default SDK for all boards
@@ -53,7 +54,7 @@ compiler.libc.path={runtime.platform.path}/tools/sdk/libc/xtensa-lx106-elf
 compiler.cpreprocessor.flags=-D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ "-I{compiler.sdk.path}/include" "-I{compiler.sdk.path}/{build.lwip_include}" "-I{compiler.libc.path}/include" "-I{build.path}/core"
 
 compiler.c.cmd=xtensa-lx106-elf-gcc
-compiler.c.flags=-c {compiler.warning_flags} -Os -g -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -std=gnu99 -ffunction-sections -fdata-sections {build.exception_flags} {build.sslflags}
+compiler.c.flags=-c {compiler.warning_flags} -Os -g -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -std=gnu99 -ffunction-sections -fdata-sections {build.exception_flags} {build.sslflags} {build.floatflags}
 
 compiler.S.cmd=xtensa-lx106-elf-gcc
 compiler.S.flags=-c -g -x assembler-with-cpp -MMD -mlongcalls
@@ -64,7 +65,7 @@ compiler.c.elf.cmd=xtensa-lx106-elf-gcc
 compiler.c.elf.libs=-lhal -lphy -lpp -lnet80211 {build.lwip_lib} -lwpa -lcrypto -lmain -lwps -lbearssl -laxtls -lespnow -lsmartconfig -lairkiss -lwpa2 {build.stdcpp_lib} -lm -lc -lgcc
 
 compiler.cpp.cmd=xtensa-lx106-elf-g++
-compiler.cpp.flags=-c {compiler.warning_flags} -Os -g -mlongcalls -mtext-section-literals -fno-rtti -falign-functions=4 {build.stdcpp_level} -MMD -ffunction-sections -fdata-sections {build.exception_flags} {build.sslflags}
+compiler.cpp.flags=-c {compiler.warning_flags} -Os -g -mlongcalls -mtext-section-literals -fno-rtti -falign-functions=4 {build.stdcpp_level} -MMD -ffunction-sections -fdata-sections {build.exception_flags} {build.sslflags} {build.floatflags}
 
 compiler.as.cmd=xtensa-lx106-elf-as
 

tools/boards.txt.py

@@ -1588,6 +1588,7 @@ def all_boards ():
 
         if nofloat:
             print(id + '.build.float=')
+            print(id + '.build.floatflags=-DNOPRINTFLOAT')
 
         print('')