[clang-tools-extra] 8848324 - [clangd] Avoid a code completion crash

[Haojian Wu via cfe-commits]

Author: Haojian Wu
Date: 2022-01-17T10:35:55+01:00
New Revision: 884832407e47579a28e8c363492a620901f2eab4

URL: https://github.com/llvm/llvm-project/commit/884832407e47579a28e8c363492a620901f2eab4
DIFF: https://github.com/llvm/llvm-project/commit/884832407e47579a28e8c363492a620901f2eab4.diff

LOG: [clangd] Avoid a code completion crash

This is a workaround (adding a newline to the eof) in clangd to avoid the code
completion crash, see https://github.com/clangd/clangd/issues/332.

In principle, this is a clang bug, we should fix it in clang, but it is not
trivial.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D117456

Added: 
    

Modified: 
    clang-tools-extra/clangd/ClangdServer.cpp
    clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
index 29d5d9dfe1d1..34fc71f70bb8 100644
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -369,6 +369,10 @@ void ClangdServer::codeComplete(PathRef File, Position Pos,
       }
     }
     ParseInputs ParseInput{IP->Command, &TFS, IP->Contents.str()};
+    // FIXME: Add traling new line if there is none at eof, workaround a crash,
+    // see https://github.com/clangd/clangd/issues/332
+    if (!IP->Contents.endswith("\n"))
+      ParseInput.Contents.append("\n");
     ParseInput.Index = Index;
 
     CodeCompleteOpts.MainFileSignals = IP->Signals;
@@ -417,6 +421,10 @@ void ClangdServer::signatureHelp(PathRef File, Position Pos,
       return CB(error("Failed to parse includes"));
 
     ParseInputs ParseInput{IP->Command, &TFS, IP->Contents.str()};
+    // FIXME: Add traling new line if there is none at eof, workaround a crash,
+    // see https://github.com/clangd/clangd/issues/332
+    if (!IP->Contents.endswith("\n"))
+      ParseInput.Contents.append("\n");
     ParseInput.Index = Index;
     CB(clangd::signatureHelp(File, Pos, *PreambleData, ParseInput,
                              DocumentationFormat));

diff  --git a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
index e3bf5ebdb0a7..c602627c3595 100644
--- a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
@@ -2474,6 +2474,26 @@ TEST(CompletionTest, OverridesNonIdentName) {
   )cpp");
 }
 
+TEST(CompletionTest, NoCrashOnMissingNewLineAtEOF) {
+  auto FooCpp = testPath("foo.cpp");
+
+  MockCompilationDatabase CDB;
+  MockFS FS;
+  Annotations F("#pragma ^ // no new line");
+  FS.Files[FooCpp] = F.code().str();
+  ClangdServer Server(CDB, FS, ClangdServer::optsForTest());
+  runAddDocument(Server, FooCpp, F.code());
+  // Run completion outside the file range.
+  EXPECT_THAT(cantFail(runCodeComplete(Server, FooCpp, F.point(),
+                                       clangd::CodeCompleteOptions()))
+                  .Completions,
+              IsEmpty());
+  EXPECT_THAT(cantFail(runSignatureHelp(Server, FooCpp, F.point(),
+                                        MarkupKind::PlainText))
+                  .signatures,
+              IsEmpty());
+}
+
 TEST(GuessCompletionPrefix, Filters) {
   for (llvm::StringRef Case : {
            "[[scope::]][[ident]]^",