How to pass VSC variables from c_cpp_properties.json to a Task?

[rei-vilo]

I'm running a makefile with the C/C++ for Visual Studio Code extension and I've defined some configurations in c_cpp_properties.json.

How to read and get the configurations values from the makefile?

Thanks!

[sean-mcmanus]

You have to manually open the makefile and modify the includePath/defines settings in c_cpp_properties.json accordingly. Does that work for you?

[rei-vilo]

Editing the make-file works for me, but the idea was to have a better integration. Leveraging Visual Studio Code interface to set parameters and retrieving those parameters from the makefile.

Is there something like export VARIABLE=VALUE available?

[bobbrow]

Which VS Code variables are you trying to read? Our extension does not set any environment variables. The contents of c_cpp_properties.json is not exported to the environment.

[sean-mcmanus]

@rei-vilo I assume you mean editing the "c_cpp_properties.json"? You shouldn't need to edit the makefile. Are you asking for cpptools to read the makefile and set the includePath and defines ourselves? Visual Studio 2017 does that for cmake, but we haven't implemented that yet. Theoretically, anyone could write a VS Code extension (or any script) that read makefiles or other build settings and read/modified our c_cpp_properties.json to correctly set the includePath/defines.

[rei-vilo]

I've modified c_cpp_properties.json to define different configurations with tool-chains and SDK instead of the OSes.

{
    "configurations": [
        {
            "name": "LaunchPad MSP432",
            "includePath": [
                "~/Library/Energia15/packages/energia/hardware/msp432r",
                "~/Library/Energia15/packages/energia/tools/arm-none-eabi-gcc"
            ],
            "browse": {
                "limitSymbolsToIncludedHeaders": true,
                "databaseFilename": "",
                "path": [
                    "~/Library/Energia15/packages/energia/hardware/msp432r",
                    "~/Library/Energia15/packages/energia/tools/arm-none-eabi-gcc"
                ]
            }
        },
       {
            "name": "LaunchPad LM4F120",
            "includePath": [
                "~/Library/Energia15/packages/energia/hardware/tivac",
                "~/Library/Energia15/packages/energia/tools/arm-none-eabi-gcc"
            ],
            "browse": {
                "limitSymbolsToIncludedHeaders": true,
                "databaseFilename": "",
                "path": [
                    "~/Library/Energia15/packages/energia/hardware/tivac",
                    "~/Library/Energia15/packages/energia/tools/arm-none-eabi-gcc"
                ]
            }
        }
    ]
}

I need to get the "name" field so the main makefile can switch to the appropriate secondary one. Similarly, I’d like to add other fields and read them from the main makefile.

[rei-vilo]

Once a configuration is selected, e.g. LaunchPad MSP432 as per #742 (comment), how to get that value and pass it to the task Build, i.e. {{name}}?

{
    "version": "0.1.0",
    "isShellCommand": true,
    "tasks": [
        {
            "taskName": "Build",
            "isBuildCommand": true,
            "showOutput": "always",
            "command": "make",
            "args": ["build", {{name}}],
            "suppressTaskName": true,
            "problemMatcher": {
                "owner": "cpp",
                "fileLocation": ["relative", "${workspaceRoot}"],
                "pattern": {
                    "regexp": "^(.*):(\\d+):(\\d+):\\s+(warning|error):\\s+(.*)$",
                    "file": 1,
                    "line": 2,
                    "column": 3,
                    "severity": 4,
                    "message": 5
                }
            }
        }
    ]
}

[rei-vilo]

Title How to pass VSC variables from c_cpp_properties.json to a Task? seems more appropriate.

[sean-mcmanus]

@rei-vilo There is currently no way to automatically get the value of the cpptools configuration name.

[rei-vilo]

Ok, thanks, this is a show-stopper.

[rei-vilo]

@czgtest

Maybe you can help on this issue too.

[bobbrow]

microsoft/vscode#43782

[rei-vilo]

@bobbrow What do mean by more info needed?

[bobbrow]

I removed that tag while doing some issue cleanup last week. It was set a long time ago before we understood the issue.

[rei-vilo]

From c_cpp_properties.json reference | Configuration properties

defines A list of preprocessor definitions for the IntelliSense engine to use while parsing files. Optionally, use = to set a value, for example VERSION=1.

Why not provide a similar logic for definitions tasks.json may read and use from c_cpp_properties.json?

Integrate with External Tools via Tasks | Variable substitution details Predefined variables, Environment variables and Configuration variables, but is mum about variables defined in c_cpp_properties.json configurations.

[sean-mcmanus]

VS Code itself controls the execution of tasks.json and there's no way for us to get them to use c_cpp_properties.json info.

[bobbrow]

Sorry, I should have resolved this issue a long time ago. VS Code added a feature that lets us do this and we added a command to get the active configuration name that you can use in your tasks.json.

${command:cpptools.activeConfigName}

[rei-vilo]

Thank you!

[rei-vilo]

@bobbrow It works fine.

Where can I find the documentation related to this feature? Pages Customizing default settings and c_cpp_properties.json reference for the C++ extension, and page Integrate with External Tools via Tasks for Tasks, do not mention cpptools.activeConfigName.

Thank you!