From 99930623efd65e542481294b5f09f9295559d0e7 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Thu, 11 Apr 2019 22:26:07 -0700
Subject: [PATCH] Set RetainCommentsFromSystemHeaders to true

Note with -fretain-comments-from-system-headers, the .gch of bits/stdc++.h becomes larger by 1%, but that is fine.

And improve comment handling in textDocument/hover

Fix #373
---
 src/indexer.cc                     | 4 ++--
 src/messages/textDocument_hover.cc | 7 ++++---
 src/sema_manager.cc                | 1 +
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/indexer.cc b/src/indexer.cc
index 59135710..066fc9f1 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -1238,8 +1238,8 @@ Index(SemaManager *manager, WorkingFiles *wfiles, VFS *vfs,
   ok = false;
   // -fparse-all-comments enables documentation in the indexer and in
   // code completion.
-  if (g_config->index.comments > 1)
-    CI->getLangOpts()->CommentOpts.ParseAllComments = true;
+  CI->getLangOpts()->CommentOpts.ParseAllComments = g_config->index.comments > 1;
+  CI->getLangOpts()->RetainCommentsFromSystemHeaders = true;
   std::string buf = wfiles->GetContent(main);
   std::vector<std::unique_ptr<llvm::MemoryBuffer>> Bufs;
   if (buf.size())
diff --git a/src/messages/textDocument_hover.cc b/src/messages/textDocument_hover.cc
index a67a9272..1e9781af 100644
--- a/src/messages/textDocument_hover.cc
+++ b/src/messages/textDocument_hover.cc
@@ -60,8 +60,11 @@ GetHover(DB *db, LanguageId lang, SymbolRef sym, int file_id) {
   std::optional<MarkedString> ls_comments, hover;
   WithEntity(db, sym, [&](const auto &entity) {
     for (auto &d : entity.def) {
+      if (!comments && d.comments[0])
+        comments = d.comments;
       if (d.spell) {
-        comments = d.comments[0] ? d.comments : nullptr;
+        if (d.comments[0])
+          comments = d.comments;
         if (const char *s =
                 d.hover[0] ? d.hover
                            : d.detailed_name[0] ? d.detailed_name : nullptr) {
@@ -76,8 +79,6 @@ GetHover(DB *db, LanguageId lang, SymbolRef sym, int file_id) {
     }
     if (!hover && entity.def.size()) {
       auto &d = entity.def[0];
-      if (d.comments[0])
-        comments = d.comments;
       hover = {LanguageIdentifier(lang)};
       if (d.hover[0])
         hover->value = d.hover;
diff --git a/src/sema_manager.cc b/src/sema_manager.cc
index 096f2c16..d8e7608e 100644
--- a/src/sema_manager.cc
+++ b/src/sema_manager.cc
@@ -363,6 +363,7 @@ void BuildPreamble(Session &session, CompilerInvocation &CI,
   CI.getDiagnosticOpts().IgnoreWarnings = false;
   CI.getFrontendOpts().SkipFunctionBodies = true;
   CI.getLangOpts()->CommentOpts.ParseAllComments = g_config->index.comments > 1;
+  CI.getLangOpts()->RetainCommentsFromSystemHeaders = true;
 
   StoreDiags DC(task.path);
   IntrusiveRefCntPtr<DiagnosticsEngine> DE =