[clangd] Add HeaderInsertion yaml config option

This is the yaml config equivalent of `--header-insertion` CLI option

Author: MythreyaK

clang-tools-extra/clangd/ClangdServer.cpp

@@ -455,6 +455,7 @@ void ClangdServer::codeComplete(PathRef File, Position Pos,
     CodeCompleteOpts.MainFileSignals = IP->Signals;
     CodeCompleteOpts.AllScopes = Config::current().Completion.AllScopes;
     CodeCompleteOpts.ArgumentLists = Config::current().Completion.ArgumentLists;
+    CodeCompleteOpts.InsertIncludes = Config::current().HeaderInsertion.Policy;
     // FIXME(ibiryukov): even if Preamble is non-null, we may want to check
     // both the old and the new version in case only one of them matches.
     CodeCompleteResult Result = clangd::codeComplete(

clang-tools-extra/clangd/CodeComplete.cpp

@@ -294,7 +294,8 @@ struct CompletionCandidate {
   std::optional<llvm::StringRef>
   headerToInsertIfAllowed(const CodeCompleteOptions &Opts,
                           CodeCompletionContext::Kind ContextKind) const {
-    if (Opts.InsertIncludes == CodeCompleteOptions::NeverInsert ||
+    if (Opts.InsertIncludes ==
+            CodeCompleteOptions::IncludeInsertion::NeverInsert ||
         RankedIncludeHeaders.empty() ||
         !contextAllowsHeaderInsertion(ContextKind))
       return std::nullopt;

clang-tools-extra/clangd/CodeComplete.h

@@ -71,10 +71,8 @@ struct CodeCompleteOptions {
   /// Whether to present doc comments as plain-text or markdown.
   MarkupKind DocumentationFormat = MarkupKind::PlainText;
 
-  enum IncludeInsertion {
-    IWYU,
-    NeverInsert,
-  } InsertIncludes = IncludeInsertion::IWYU;
+  using IncludeInsertion = Config::HeaderInsertionPolicy;
+  Config::HeaderInsertionPolicy InsertIncludes = IncludeInsertion::IWYU;
 
   /// Whether include insertions for Objective-C code should use #import instead
   /// of #include.

clang-tools-extra/clangd/Config.h

@@ -151,6 +151,15 @@ struct Config {
     ArgumentListsPolicy ArgumentLists = ArgumentListsPolicy::FullPlaceholders;
   } Completion;
 
+  enum class HeaderInsertionPolicy {
+    IWYU,       // Include what you use
+    NeverInsert // Never insert headers as part of code completion
+  };
+
+  struct {
+    HeaderInsertionPolicy Policy = HeaderInsertionPolicy::IWYU;
+  } HeaderInsertion;
+
   /// Configures hover feature.
   struct {
     /// Whether hover show a.k.a type.

clang-tools-extra/clangd/ConfigCompile.cpp

@@ -685,6 +685,17 @@ struct FragmentCompiler {
           C.Completion.ArgumentLists = *Val;
         });
     }
+    if (F.HeaderInsertion) {
+      if (auto Val =
+              compileEnum<Config::HeaderInsertionPolicy>("HeaderInsertion",
+                                                         *F.HeaderInsertion)
+                  .map("IWYU", Config::HeaderInsertionPolicy::IWYU)
+                  .map("Never", Config::HeaderInsertionPolicy::NeverInsert)
+                  .value())
+        Out.Apply.push_back([Val](const Params &, Config &C) {
+          C.HeaderInsertion.Policy = *Val;
+        });
+    }
   }
 
   void compile(Fragment::HoverBlock &&F) {

clang-tools-extra/clangd/ConfigFragment.h

@@ -333,6 +333,14 @@ struct Fragment {
     ///   Delimiters: empty pair of delimiters "()" or "<>"
     ///   FullPlaceholders: full name of both type and parameter
     std::optional<Located<std::string>> ArgumentLists;
+    /// Add #include directives when accepting code completions. Config
+    /// equivalent of the CLI option '--header-insertion'
+    /// Valid values are enum Config::HeaderInsertionPolicy values:
+    ///   "IWYU": Include what you use. Insert the owning header for top-level
+    ///     symbols, unless the header is already directly included or the
+    ///     symbol is forward-declared
+    ///   "NeverInsert": Never insert headers
+    std::optional<Located<std::string>> HeaderInsertion;
   };
   CompletionBlock Completion;
 

clang-tools-extra/clangd/ConfigYAML.cpp

@@ -241,6 +241,10 @@ class Parser {
       if (auto ArgumentLists = scalarValue(N, "ArgumentLists"))
         F.ArgumentLists = *ArgumentLists;
     });
+    Dict.handle("HeaderInsertion", [&](Node &N) {
+      if (auto HeaderInsertion = scalarValue(N, "HeaderInsertion"))
+        F.HeaderInsertion = *HeaderInsertion;
+    });
     Dict.parse(N);
   }
 

clang-tools-extra/clangd/tool/ClangdMain.cpp

@@ -257,13 +257,13 @@ opt<CodeCompleteOptions::IncludeInsertion> HeaderInsertion{
     desc("Add #include directives when accepting code completions"),
     init(CodeCompleteOptions().InsertIncludes),
     values(
-        clEnumValN(CodeCompleteOptions::IWYU, "iwyu",
+        clEnumValN(CodeCompleteOptions::IncludeInsertion::IWYU, "iwyu",
                    "Include what you use. "
                    "Insert the owning header for top-level symbols, unless the "
                    "header is already directly included or the symbol is "
                    "forward-declared"),
         clEnumValN(
-            CodeCompleteOptions::NeverInsert, "never",
+            CodeCompleteOptions::IncludeInsertion::NeverInsert, "never",
             "Never insert #include directives as part of code completion")),
 };
 

clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

@@ -882,7 +882,8 @@ TEST(CompletionTest, IncludeInsertionPreprocessorIntegrationTests) {
               ElementsAre(AllOf(named("X"), insertInclude("\"bar.h\""))));
   // Can be disabled via option.
   CodeCompleteOptions NoInsertion;
-  NoInsertion.InsertIncludes = CodeCompleteOptions::NeverInsert;
+  NoInsertion.InsertIncludes =
+      CodeCompleteOptions::IncludeInsertion::NeverInsert;
   Results = completions(TU, Test.point(), {Sym}, NoInsertion);
   EXPECT_THAT(Results.Completions,
               ElementsAre(AllOf(named("X"), Not(insertInclude()))));