[clangd] Use identifiers in file as completion candidates when build is not ready.

Summary:
o Lex the code to get the identifiers and put them into a "symbol" index.
o Adds a new completion mode without compilation/sema into code completion workflow.
o Make IncludeInserter work even when no compile command is present, by avoiding
inserting non-verbatim headers.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60126

llvm-svn: 358159

1 files changed, 20 insertions, 2 deletions

diff --git a/clang-tools-extra/unittests/clangd/HeadersTests.cpp b/clang-tools-extra/unittests/clangd/HeadersTests.cpp
index ab1311e2e60..2c96d40a9d4 100644
--- a/clang-tools-extra/unittests/clangd/HeadersTests.cpp
+++ b/clang-tools-extra/unittests/clangd/HeadersTests.cpp
@@ -90,7 +90,7 @@ protected:
 
     IncludeInserter Inserter(MainFile, /*Code=*/"", format::getLLVMStyle(),
                              CDB.getCompileCommand(MainFile)->Directory,
-                             Clang->getPreprocessor().getHeaderSearchInfo());
+                             &Clang->getPreprocessor().getHeaderSearchInfo());
     for (const auto &Inc : Inclusions)
       Inserter.addExisting(Inc);
     auto Declaring = ToHeaderFile(Original);
@@ -110,7 +110,7 @@ protected:
 
     IncludeInserter Inserter(MainFile, /*Code=*/"", format::getLLVMStyle(),
                              CDB.getCompileCommand(MainFile)->Directory,
-                             Clang->getPreprocessor().getHeaderSearchInfo());
+                             &Clang->getPreprocessor().getHeaderSearchInfo());
     auto Edit = Inserter.insert(VerbatimHeader);
     Action.EndSourceFile();
     return Edit;
@@ -252,6 +252,24 @@ TEST_F(HeadersTest, PreferInserted) {
   EXPECT_TRUE(StringRef(Edit->newText).contains("<y>"));
 }
 
+TEST(Headers, NoHeaderSearchInfo) {
+  std::string MainFile = testPath("main.cpp");
+  IncludeInserter Inserter(MainFile, /*Code=*/"", format::getLLVMStyle(),
+                           /*BuildDir=*/"", /*HeaderSearchInfo=*/nullptr);
+
+  auto HeaderPath = testPath("sub/bar.h");
+  auto Declaring = HeaderFile{HeaderPath, /*Verbatim=*/false};
+  auto Inserting = HeaderFile{HeaderPath, /*Verbatim=*/false};
+  auto Verbatim = HeaderFile{"<x>", /*Verbatim=*/true};
+
+  EXPECT_EQ(Inserter.calculateIncludePath(Declaring, Inserting),
+            "\"" + HeaderPath + "\"");
+  EXPECT_EQ(Inserter.shouldInsertInclude(Declaring, Inserting), false);
+
+  EXPECT_EQ(Inserter.calculateIncludePath(Declaring, Verbatim), "<x>");
+  EXPECT_EQ(Inserter.shouldInsertInclude(Declaring, Verbatim), true);
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang