Option to resolve build diagnostics relative to workspace folder

[i-ky]

Brief Issue Summary

It is a known problem that achieving reproducible builds with CMake requires hacks and workarounds, especially if compiler in use does not support -ffile-prefix-map. In our project we apply some trickery to ensure that compiler is always invoked from the source root with a relative path to source file. As a result of that, compiler prints all errors and warnings with paths relative to the source root instead of absolute paths or paths relative to build directory:

[build] some/path/relative/to/source/root/foo.cpp:12:2: error: #error test
[build]  #error test
[build]   ^

This confuses CMake Tools, if extension detects that path is relative, it appends it to build directory. In Problems tab we see something like:

foo.cpp build/directory/some/path/relative/to/source/root
#error test GCC [12, 2]

Some relevant code:

vscode-cmake-tools/src/cmake-tools.ts

Line 912 in 8faa5da

const file_diags = consumer.compileConsumer.resolveDiagnostics(drv.binaryDir);

vscode-cmake-tools/src/diagnostics/build.ts

Line 43 in 8faa5da

resolveDiagnostics(basePath: string): FileDiagnostic[] {

vscode-cmake-tools/src/diagnostics/build.ts

Line 71 in 8faa5da

const filepath = util.resolvePath(raw_diag.file, basePath);

vscode-cmake-tools/src/diagnostics/build.ts

Line 82 in 8faa5da

const relFilePath = vscode.Uri.file(util.resolvePath(rel.file, basePath));

vscode-cmake-tools/src/util.ts

Lines 127 to 131 in 8faa5da

	export function resolvePath(inpath: string, base: string) {
	const abspath = path.isAbsolute(inpath) ? inpath : path.join(base, inpath);
	// Even absolute paths need to be normalized since they could contain rogue .. and .
	return lightNormalizePath(abspath);
	}

Expected:

We need some sort of configuration option to be able to resolve compiler diagnostics relative to the source root.

Apparent Behavior:

Currently, diagnostics are reported with wrong file path and cannot be opened by clicking on them.

Unable to open 'foo.cpp': Unable to read file '/workspace/folder/build/directory/some/path/relative/to/source/root/foo.cpp' (Error: Unable to resolve non-existing file '/workspace/folder/build/directory/some/path/relative/to/source/root/foo.cpp').

Platform and Versions

• Operating System: Ubuntu 16.04
• CMake Version: 3.15.5
• VSCode Version: 1.47.3
• CMake Tools Extension Version: 0.29.0
• Compiler/Toolchain: GCC 4.9.3

[bobbrow]

If you would like to add a new setting (e.g. cmake.buildDiagnosticsRootPath) and do a PR for this feature, we would be happy to review and accept it.

[i-ky]

We managed to work around the issue using

"cmake.buildTask": true

in settings.json and a custom build task in tasks.json:

{
    "label": "Build selected configuration",
    "group": {
        "kind": "build",
        "isDefault": true
    },
    "type": "shell",
    "command": "/bin/bash",
    "args": [
        "-c",
        "${command:cmake.tasksBuildCommand}"
    ],
    "problemMatcher": "$gcc"
}

This way we gained control over problemMatcher and now it seems to be doing the right thing.

I have to say it took us a while to figure out how cmake.buildTask was supposed to work, it is a pity that #647 got merged without documentation update.

[dagar]

I've come across the same problem with the current workaround of using a custom build task that sets a relative file location for the problemMatcher.

        {
            "label": "build",
            "type": "shell",
            "command": "/bin/bash",
            "args": [
                "-c",
                "${command:cmake.tasksBuildCommand}"
            ],
            "options": {
                "cwd": "${command:cmake.buildDirectory}"
            },
            "group": {
                "kind": "build",
                "isDefault": true,
            },
            "problemMatcher": {
                "base": "$gcc",
                "fileLocation": ["relative", "${command:cmake.buildDirectory}"]
            }
        },

Is this not in general the right thing to do with cmake? With Ninja it doesn't appear to be possible to have non-relative paths.

[github-actions]

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[v-frankwang]

@i-ky We have attempted to verify this issue on CMake tools: v1.19.45, but we don't have detailed reproduction steps to reproduce it. Are you able to go and verify that the issue is fixed?

[i-ky]

Hi @v-frankwang!

The thing is, I reported this issue while working on a closed source commercial project. That's why there aren't too many details in the description. Since then I have switched a couple of workplaces, so I cannot verify if the fix is working for the original use case. I have reached out to my ex-colleague asking to verify and if I get any feedback I will let you know.

From what I see in #3780 the fix should be OK.

Maybe @fargies, the author of #3780, can provide detailed steps to reproduce?

As a last resort you can write a small script pretending to be a compiler and mock error messages using it.

[v-frankwang]

@i-ky Thank you very much for your reply, I hope you can update the review if you can verify this.