[clangd] Initial supoprt for cross-namespace global code completion.

Summary:
When no scope qualifier is specified, allow completing index symbols
from any scope and insert proper automatically. This is still experimental and
hidden behind a flag.

Things missing:
- Scope proximity based scoring.
- FuzzyFind supports weighted scopes.

Reviewers: sammccall

Reviewed By: sammccall

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

Differential Revision: https://reviews.llvm.org/D52364

llvm-svn: 343248

1 files changed, 10 insertions, 0 deletions

diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
index 4c6a4c35246..aebff518932 100644
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -136,6 +136,15 @@ static llvm::cl::opt<bool> EnableIndex(
         "enabled separatedly."),
     llvm::cl::init(true), llvm::cl::Hidden);
 
+static llvm::cl::opt<bool> AllScopesCompletion(
+    "all-scopes-completion",
+    llvm::cl::desc(
+        "If set to true, code completion will include index symbols that are "
+        "not defined in the scopes (e.g. "
+        "namespaces) visible from the code completion point. Such completions "
+        "can insert scope qualifiers."),
+    llvm::cl::init(false), llvm::cl::Hidden);
+
 static llvm::cl::opt<bool>
     ShowOrigins("debug-origin",
                 llvm::cl::desc("Show origins of completion items"),
@@ -304,6 +313,7 @@ int main(int argc, char *argv[]) {
   }
   CCOpts.SpeculativeIndexRequest = Opts.StaticIndex;
   CCOpts.EnableFunctionArgSnippets = EnableFunctionArgSnippets;
+  CCOpts.AllScopes = AllScopesCompletion;
 
   // Initialize and run ClangdLSPServer.
   ClangdLSPServer LSPServer(