VS Code reports language server error related to generated compilerPath in c_cpp_properties.json by Arduino extension

[milanbx]

Environment

Version: 1.74.3
Commit: 97dec172d3256f8ca4bfb2143f3f76b503ca0534
Date: 2023-01-09T16:59:02.252Z
Electron: 19.1.8
Chromium: 102.0.5005.167
Node.js: 16.14.2
V8: 10.2.154.15-electron.0
OS: Windows_NT x64 10.0.19045
Sandboxed: No

Bug Summary

After upgrading ESP8266/Arduino core to v3.1.1, the Arduino extension regenerated th c_cpp_properties.json file with a compilerPath attribute having value causing following C/C++ configuration error:
Unable to resolve configuration with compilerPath: "@D:\Portable\Arduino\portable\packages\esp8266\hardware\esp8266\3.1.1\tools\warnings\default-g++"
On top of this line from C/C++ Configuration Warning output, the Code UI shows 5 instances of cpptools output windows, all having same content (see also snapshot below):
[Error - 18:20:27] Connection to server got closed. Server will not be restarted.

Then, the intellisense stops working at all, no cross reference can be followed (Ctrl+left mouse click) to see details of function or variable declaration etc.

Steps to reproduce

Just run VS Code, open any sketch with Arduino code (*.ino), even empty one. Popup error start to come up in the lower right corner - see snapshot:

Code snippet

Every, does not matter, even this simple blinking LED example:

byte go = LOW;
void setup() {
    pinMode(LED_BUILTIN, OUTPUT);
    digitalWrite(LED_BUILTIN, go);
}
void loop() {
    delay(500);
    go = 1 - go;
    digitalWrite(LED_BUILTIN, go);
}

Configuration

{
    "version": 4,
    "configurations": [
        {
            "name": "Arduino",
            "compilerPath": "@D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\tools\\warnings\\default-g++",
            "compilerArgs": [
                "-U__STRICT_ANSI__",
                "-free",
                "-fipa-pta",
                "-Werror=return-type",
                "-mlongcalls",
                "-mtext-section-literals",
                "-fno-rtti",
                "-falign-functions=4",
                "-std=gnu++17"
            ],
            "intelliSenseMode": "gcc-x64",
            "includePath": [
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\tools\\sdk\\include",
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\tools\\sdk\\lwip2\\include",
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\cores\\esp8266",
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\variants\\generic",
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\libraries\\ESP8266WiFi\\src"
            ],
            "forcedInclude": [
                "D:\\Portable\\Arduino\\portable\\packages\\esp8266\\hardware\\esp8266\\3.1.1\\cores\\esp8266\\Arduino.h"
            ],
            "cStandard": "c11",
            "cppStandard": "c++17",
            "defines": [
                "__ets__",
                "ICACHE_FLASH",
                "_GNU_SOURCE",
                "ESP8266",
                "MMU_IRAM_SIZE=0x8000",
                "MMU_ICACHE_SIZE=0x8000",
                "NONOSDK22x_191122=1",
                "F_CPU=80000000L",
                "LWIP_OPEN_SRC",
                "TCP_MSS=536",
                "LWIP_FEATURES=1",
                "LWIP_IPV6=0",
                "ARDUINO=10819",
                "ARDUINO_ESP8266_GENERIC",
                "ARDUINO_ARCH_ESP8266",
                "ARDUINO_BOARD=\"ESP8266_GENERIC\"",
                "ARDUINO_BOARD_ID=\"generic\"",
                "LED_BUILTIN=2",
                "FLASHMODE_DOUT",
                "USBCON"
            ]
        }
    ]
}

Other Extensions

Arduino: 0.4.12
C/C++ Extension Pack: 1.3.0

VS Code Dev Tools Console Log

vscode-app-1673804966418.log

[Colengms]

Hi @milanbx .

The "@" followed by a path is a valid compiler argument for gcc, clang and CL.exe. It indicates that additional arguments should be read from the indicated file.

https://gcc.gnu.org/onlinedocs/gcc/Overall-Options.html#Overall-Options (bottom of the page)

https://learn.microsoft.com/en-us/cpp/build/reference/at-specify-a-compiler-response-file?view=msvc-170

However, the C/C++ extension does not support that syntax when used as the compiler path itself, only as an argument to a compiler that supports it. If the Arduino extension generated that compilerPath, I'd suggest opening an issue about it in the Arduino extension repo

[milanbx]

Hi @Colengms and thanks for your explanation of the "@" prefix. I was wondering too, what that usage means of this syntax pointing to whole path of files instead of one. Arduino extension might generate this in gooe faith, it will instruct the compiler to look into every configuration file in the targeted folder.
Anyway, it does not matter and I have also opend an issue in Arduino repo: microsoft/vscode-arduino#1567
But also in ESP8266 core repo: esp8266/Arduino#8809
I will also add a link to your answer in that issue.
Thanks for help.

[Colengms]

Hi @milanbx .

Also, I'm not able to reproduce the crash you are seeing. Which version of the C/C++ extension are you reproducing this with?

Would you be able to connect the debugger to cpptools.exe, and get a stack from the crash? Assuming the crash is related to an issue with the configuration, you may be able to temporarily modify or rename c_cpp_properties.json long enough to connect the debugger, then restore it to trigger the crash.

https://github.com/microsoft/vscode-cpptools/wiki/Attaching-debugger-to-cpptools-or-cpptools%E2%80%90srv

[milanbx]

The C/C++ for Visual Studio Code is version 1.13.9, bundled within C/C++ Extension Pack version 1.3.0.
As for connecting the debuger to cpptools.exe, I was not successfull. I have followed the procedure as describer in the article, but failed in the step, where the process should be found - no such process exists (see snapshot):

I have renamed the c_cpp_properties.json file prior to teh attempt.

[Colengms]

Hi @milanbx . I believe I closed this issue prematurely, based on the first part being resolved. Are you still able to reproduce the crash?

[milanbx]

Hi, the issue was casused by Arduino ESP8266 Core liberary settings and solved here: esp8266/Arduino#8809. I am not able to reproduce this again. Thanks.