[clang-tools-extra] [clangd] Improve BlockEnd inlay hints presentation (PR #72345)

[via cfe-commits]

https://github.com/daiyousei-qz created https://github.com/llvm/llvm-project/pull/72345

Including:
1. Explicitly state a function call
2. Print literal nullptr
3. Escape for abbreviated string
4. Adjust min line limit to 10

Fixes issue [clangd/clangd#1807](https://github.com/clangd/clangd/issues/1807)

>From 1a196e908998e9ba1edf9a9c0a48877138b1a223 Mon Sep 17 00:00:00 2001
From: daiyousei-qz <qyzheng2 at outlook.com>
Date: Tue, 14 Nov 2023 20:42:10 -0800
Subject: [PATCH] Improve BlockEnd presentation including: 1. Explicitly state
 a function call 2. Print literal nullptr 3. Escape for abbreviated string 4.
 Adjust min line limit to 10

---
 clang-tools-extra/clangd/InlayHints.cpp | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/clang-tools-extra/clangd/InlayHints.cpp b/clang-tools-extra/clangd/InlayHints.cpp
index 3da047f95421385..97b467fbb519dbd 100644
--- a/clang-tools-extra/clangd/InlayHints.cpp
+++ b/clang-tools-extra/clangd/InlayHints.cpp
@@ -266,7 +266,9 @@ std::string summarizeExpr(const Expr *E) {
       return getSimpleName(*E->getFoundDecl()).str();
     }
     std::string VisitCallExpr(const CallExpr *E) {
-      return Visit(E->getCallee());
+      std::string Result = Visit(E->getCallee());
+      Result += E->getNumArgs() == 0 ? "()" : "(...)";
+      return Result;
     }
     std::string
     VisitCXXDependentScopeMemberExpr(const CXXDependentScopeMemberExpr *E) {
@@ -301,6 +303,9 @@ std::string summarizeExpr(const Expr *E) {
     }
 
     // Literals are just printed
+    std::string VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E) {
+      return "nullptr";
+    }
     std::string VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
       return E->getValue() ? "true" : "false";
     }
@@ -319,12 +324,14 @@ std::string summarizeExpr(const Expr *E) {
       std::string Result = "\"";
       if (E->containsNonAscii()) {
         Result += "...";
-      } else if (E->getLength() > 10) {
-        Result += E->getString().take_front(7);
-        Result += "...";
       } else {
         llvm::raw_string_ostream OS(Result);
-        llvm::printEscapedString(E->getString(), OS);
+        if (E->getLength() > 10) {
+          llvm::printEscapedString(E->getString().take_front(7), OS);
+          Result += "...";
+        } else {
+          llvm::printEscapedString(E->getString(), OS);
+        }
       }
       Result.push_back('"');
       return Result;
@@ -1193,7 +1200,7 @@ class InlayHintVisitor : public RecursiveASTVisitor<InlayHintVisitor> {
   // Otherwise, the hint shouldn't be shown.
   std::optional<Range> computeBlockEndHintRange(SourceRange BraceRange,
                                                 StringRef OptionalPunctuation) {
-    constexpr unsigned HintMinLineLimit = 2;
+    constexpr unsigned HintMinLineLimit = 10;
 
     auto &SM = AST.getSourceManager();
     auto [BlockBeginFileId, BlockBeginOffset] =