Ignore unused lambda warning

Arkham commented 3 years ago

Trying to compile this on nix 21.05 caused this error:

[ 33%] Building CXX object CMakeFiles/debugir.dir/DebugIR.cpp.o
/tmp/nix-build-debugir.drv-0/source/DebugIR.cpp:322:34: error: lambda capture 'I' is not used [-Werror,-Wunused-lambda-capture]
    auto returnFallback = [this, I]() {
                               ~~^
1 error generated.
make[2]: *** [CMakeFiles/debugir.dir/build.make:82: CMakeFiles/debugir.dir/DebugIR.cpp.o] Error 1

Here are the files I used:

$ cat debugir/shell.nix
let
  sources = import ./nix/sources.nix { };
  nixpkgs = import sources.nixpkgs { };
in with nixpkgs;
mkShell { buildInputs = [ cmake libxml2 llvmPackages_12.llvm.dev ]; }

$ cat debugir/nix/sources.json
{
    "nixpkgs": {
        "branch": "release-21.05",
        "description": "Nix Packages collection",
        "homepage": "",
        "owner": "NixOS",
        "repo": "nixpkgs",
        "rev": "5f244caea76105b63d826911b2a1563d33ff1cdc",
        "sha256": "1xlgynfw9svy7nvh9nkxsxdzncv9hg99gbvbwv3gmrhmzc3sar75",
        "type": "tarball",
        "url": "https://github.com/NixOS/nixpkgs/archive/5f244caea76105b63d826911b2a1563d33ff1cdc.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    }
}

After making this change, the project compiles fine!

vaivaswatha commented 3 years ago

Thank you @Arkham. This warning is generated by clang (and not g++). Rather than disabling the warning, may I suggest that we take care of this by adding (void)I inside the lambda so that there is always a use of I ? This problem is currently only on Release builds, where LLVM_DEBUG is removed. Adding a forced use (void)I should take care of it.

Please edit your PR and I'll be happy to merge it.

Arkham commented 3 years ago

hey @vaivaswatha gladly! updated and pushed :)

vaivaswatha commented 3 years ago

Thanks @Arkham

vaivaswatha / debugir

Ignore unused lambda warning #4