3 files changed, 41 insertions, 18 deletions

diff --git a/clang-tools-extra/clangd/ClangdUnit.cpp b/clang-tools-extra/clangd/ClangdUnit.cpp
index 41f2df3669e..105bdb1fe8e 100644
--- a/clang-tools-extra/clangd/ClangdUnit.cpp
+++ b/clang-tools-extra/clangd/ClangdUnit.cpp
@@ -153,6 +153,10 @@ ParsedAST::Build(std::unique_ptr<clang::CompilerInvocation> CI,
                  std::unique_ptr<llvm::MemoryBuffer> Buffer,
                  std::shared_ptr<PCHContainerOperations> PCHs,
                  IntrusiveRefCntPtr<vfs::FileSystem> VFS) {
+  assert(CI);
+  // Command-line parsing sets DisableFree to true by default, but we don't want
+  // to leak memory in clangd.
+  CI->getFrontendOpts().DisableFree = false;
   const PrecompiledPreamble *PreamblePCH =
       Preamble ? &Preamble->Preamble : nullptr;
 
diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
index 4adb80c8470..cfebb3e3c94 100644
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -699,26 +699,13 @@ bool semaCodeComplete(std::unique_ptr<CodeCompleteConsumer> Consumer,
     log("Couldn't create CompilerInvocation");;
     return false;
   }
-  CI->getFrontendOpts().DisableFree = false;
+  auto &FrontendOpts = CI->getFrontendOpts();
+  FrontendOpts.DisableFree = false;
+  FrontendOpts.SkipFunctionBodies = true;
   CI->getLangOpts()->CommentOpts.ParseAllComments = true;
-
-  std::unique_ptr<llvm::MemoryBuffer> ContentsBuffer =
-      llvm::MemoryBuffer::getMemBufferCopy(Input.Contents, Input.FileName);
-
-  // The diagnostic options must be set before creating a CompilerInstance.
-  CI->getDiagnosticOpts().IgnoreWarnings = true;
-  // We reuse the preamble whether it's valid or not. This is a
-  // correctness/performance tradeoff: building without a preamble is slow, and
-  // completion is latency-sensitive.
-  auto Clang = prepareCompilerInstance(
-      std::move(CI), Input.Preamble, std::move(ContentsBuffer),
-      std::move(Input.PCHs), std::move(Input.VFS), DummyDiagsConsumer);
-
   // Disable typo correction in Sema.
-  Clang->getLangOpts().SpellChecking = false;
-
-  auto &FrontendOpts = Clang->getFrontendOpts();
-  FrontendOpts.SkipFunctionBodies = true;
+  CI->getLangOpts()->SpellChecking = false;
+  // Setup code completion.
   FrontendOpts.CodeCompleteOpts = Options;
   FrontendOpts.CodeCompletionAt.FileName = Input.FileName;
   auto Offset = positionToOffset(Input.Contents, Input.Pos);
@@ -731,6 +718,18 @@ bool semaCodeComplete(std::unique_ptr<CodeCompleteConsumer> Consumer,
            FrontendOpts.CodeCompletionAt.Column) =
       offsetToClangLineColumn(Input.Contents, *Offset);
 
+  std::unique_ptr<llvm::MemoryBuffer> ContentsBuffer =
+      llvm::MemoryBuffer::getMemBufferCopy(Input.Contents, Input.FileName);
+  // The diagnostic options must be set before creating a CompilerInstance.
+  CI->getDiagnosticOpts().IgnoreWarnings = true;
+  // We reuse the preamble whether it's valid or not. This is a
+  // correctness/performance tradeoff: building without a preamble is slow, and
+  // completion is latency-sensitive.
+  // NOTE: we must call BeginSourceFile after prepareCompilerInstance. Otherwise
+  // the remapped buffers do not get freed.
+  auto Clang = prepareCompilerInstance(
+      std::move(CI), Input.Preamble, std::move(ContentsBuffer),
+      std::move(Input.PCHs), std::move(Input.VFS), DummyDiagsConsumer);
   Clang->setCodeCompletionConsumer(Consumer.release());
 
   SyntaxOnlyAction Action;
diff --git a/clang-tools-extra/unittests/clangd/CodeCompleteTests.cpp b/clang-tools-extra/unittests/clangd/CodeCompleteTests.cpp
index 6ebc8f81c99..d78b4bdd579 100644
--- a/clang-tools-extra/unittests/clangd/CodeCompleteTests.cpp
+++ b/clang-tools-extra/unittests/clangd/CodeCompleteTests.cpp
@@ -18,6 +18,7 @@
 #include "TestFS.h"
 #include "index/MemIndex.h"
 #include "llvm/Support/Error.h"
+#include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
@@ -1040,6 +1041,25 @@ TEST(CompletionTest, DocumentationFromChangedFileCrash) {
               Contains(AllOf(Not(IsDocumented()), Named("func"))));
 }
 
+TEST(CompletionTest, CompleteOnInvalidLine) {
+  auto FooCpp = testPath("foo.cpp");
+
+  MockCompilationDatabase CDB;
+  IgnoreDiagnostics DiagConsumer;
+  MockFSProvider FS;
+  FS.Files[FooCpp] = "// empty file";
+
+  ClangdServer Server(CDB, FS, DiagConsumer, ClangdServer::optsForTest());
+  // Run completion outside the file range.
+  Position Pos;
+  Pos.line = 100;
+  Pos.character = 0;
+  EXPECT_THAT_EXPECTED(
+      runCodeComplete(Server, FooCpp, Pos, clangd::CodeCompleteOptions()),
+      Failed());
+}
+
+
 } // namespace
 } // namespace clangd
 } // namespace clang