sprintf statement only gives compile error if compiled with compiler warning level "All" and "More" (-Wall -Werror=all)

[ArminJo]

Board

compiler problem

Device Description

compiler problem

Hardware Configuration

compiler problem

Version

v2.0.4

IDE Name

Arduino, Sloeber

Operating System

%

Flash frequency

compiler problem

PSRAM enabled

no

Upload speed

compiler problem

Description

The sketch below throws the error

E:\WORKSPACE_ARDUINO\ArduinoSketches\sketch_jul21a\sketch_jul21a.ino: In function 'void setup()':
sketch_jul21a:7:26: error: '%s' directive writing up to 19 bytes into a region of size 14 [-Werror=format-overflow=]
   sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
   ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
E:\WORKSPACE_ARDUINO\ArduinoSketches\sketch_jul21a\sketch_jul21a.ino:7:10: note: 'sprintf' output between 7 and 26 bytes into a destination of size 20
   sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus.exe: some warnings being treated as errors
exit status 1
'%s' directive writing up to 19 bytes into a region of size 14 [-Werror=format-overflow=]

if compiled with -Wall -Werror=all

For all non ESP32 platforms it compiles without any error! - see https://github.com/ArminJo/Arduino-BlueDisplay/actions/runs/2714739545

Sketch

char sStringBuffer[20];

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  sprintf(&sStringBuffer[10], "123.4567"); // edited: original code was: dtostrf(123.45, 4, 1, &sStringBuffer[10]);
  sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
  Serial.println(sStringBuffer);
}

void loop() {
  // put your main code here, to run repeatedly:
}

Debug Message

E:\WORKSPACE_ARDUINO\ArduinoSketches\sketch_jul21a\sketch_jul21a.ino: In function 'void setup()':
sketch_jul21a:7:26: error: '%s' directive writing up to 19 bytes into a region of size 14 [-Werror=format-overflow=]
   sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
   ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
E:\WORKSPACE_ARDUINO\ArduinoSketches\sketch_jul21a\sketch_jul21a.ino:7:10: note: 'sprintf' output between 7 and 26 bytes into a destination of size 20
   sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus.exe: some warnings being treated as errors
exit status 1
'%s' directive writing up to 19 bytes into a region of size 14 [-Werror=format-overflow=]

### Other Steps to Reproduce

_No response_

### I have checked existing issues, online documentation and the Troubleshooting Guide

- [X] I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[SuGlider]

@ArminJo - I can't rerproduce the issue.

I was able to successfully compile the proposed sketch and upload the firmware to an ESP32-DevKit board.
The output is:

ets Jun  8 2016 00:22:57

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
flash read err, 1000
ets_main.c 371 
ets Jun  8 2016 00:22:57

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0030,len:1344
load:0x40078000,len:13516
load:0x40080400,len:3604
entry 0x400805f0
Acc.X 123.5

[SuGlider]

My suggestion is to remove the ESP32 board from the IDE and reinstall it again.

[ArminJo]

Du you set compiler warning level to error???
And in the log in the link, the ESP board is installed freshly ad hoc!

[SuGlider]

There is no way to set Compiler warning to error in the Arduino IDE.
Anyway, there is no warning message from the compiler when compiling this sketch.

[ArminJo]

Sorry I meant ALL like in the topic

.

[ArminJo]

Use File > Preferences

[SuGlider]

Ok, thanks, indeed, with this setup I see the error message.

[ArminJo]

Great 👍

[SuGlider]

I guess you are reading some IMU data for its Axis.
This issue can be solved by an equivalent code using sprintf().
It compiles with the preferences suggested setup and runs fine.

  //dtostrf(123.45, 4, 1, &sStringBuffer[10]);
  //sprintf(sStringBuffer, "Acc.X %s", &sStringBuffer[10]);
  float ff = 123.46;    // 123.45 results in "123.4" and 123.46 results in "123.5"
  sprintf(sStringBuffer, "Acc.X %4.1f", ff);
  Serial.println(sStringBuffer);

[SuGlider]

For testing you can directly use:
Serial.printf("Acc.X %4.1f", 123.45);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.printf("Acc.X %4.1f", 123.45);
}

void loop() {
  // put your main code here, to run repeatedly:
}

[ArminJo]

Thanks,
I know how to program and how to avoid this compiler bug.
But all compilers for all other platforms know how to compile this program without errors except the ESP32 compiler.