clang-tools: Respect $CLANGD_FLAGS in wrapper

clangd can take arguments also via environment variable CLANGD_FLAGS.
This has to be respected in the wrapper, which checks whether a
--query-driver was provided.

pkgs/development/compilers/llvm/common/clang-tools/default.nix

@@ -50,7 +50,7 @@ stdenv.mkDerivation (finalAttrs: {
     runHook postInstall
   '';
 
-  passthru.tests.smokeOk =
+  passthru.tests =
     let
       src = writeText "main.cpp" ''
         #include <iostream>
@@ -61,28 +61,24 @@ stdenv.mkDerivation (finalAttrs: {
       '';
 
     in
-    runCommand "clang-tools-test-smoke-ok" { } ''
-      ${finalAttrs.finalPackage}/bin/clangd  --check=${src}
-      touch $out
-    '';
-
-  passthru.tests.smokeErr =
-    let
-      src = writeText "main.cpp" ''
-        #include <iostream>
-
-        int main() {
-           std::cout << "Hi!";
-        }
+    {
+      smokeOk = runCommand "clang-tools-test-smoke-ok" { } ''
+        ${finalAttrs.finalPackage}/bin/clangd  --check=${src}
+        touch $out
       '';
+      smokeErr = runCommand "clang-tools-test-smoke-err" { } ''
+        (${finalAttrs.finalPackage}/bin/clangd --query-driver='**' --check=${src} 2>&1 || true) \
+            | grep 'use of undeclared identifier'
 
-    in
-    runCommand "clang-tools-test-smoke-err" { } ''
-      (${finalAttrs.finalPackage}/bin/clangd --query-driver='**' --check=${src} 2>&1 || true) \
-          | grep 'use of undeclared identifier'
+        touch $out
+      '';
+      environmentErr = runCommand "clang-tools-test-environment-err" { } ''
+         (CLANGD_FLAGS="--query-driver='**'" ${finalAttrs.finalPackage}/bin/clangd --check=${src} 2>&1 || true) \
+            | grep 'use of undeclared identifier'
 
-      touch $out
-    '';
+        touch $out
+      '';
+    };
 
   meta = llvm_meta // {
     description = "Standalone command line tools for C++ development";

pkgs/development/compilers/llvm/common/clang-tools/wrapper

@@ -40,7 +40,7 @@ buildcpluspath() {
 # don't want to infect user-specified toolchain and headers with our stuff.
 extendcpath=true
 
-for arg in "$@"; do
+for arg in "$@" $CLANGD_FLAGS; do
   if [[ "${arg}" == \-\-query\-driver* ]]; then
     extendcpath=false
   fi