[clang-tools-extra] [clangd] Clangd running with `--experimental-modules-support` crashes when the compilation database is unavailable (PR #153802)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tools-extra

Author: None (slavek-kucera)

<details>
<summary>Changes</summary>

fixes llvm/llvm-project#<!-- -->132413

---
Full diff: https://github.com/llvm/llvm-project/pull/153802.diff


1 Files Affected:

- (modified) clang-tools-extra/clangd/GlobalCompilationDatabase.cpp (+2) 


``````````diff
diff --git a/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp b/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
index 7c0eb9651feaa..8c993db2d6d02 100644
--- a/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
+++ b/clang-tools-extra/clangd/GlobalCompilationDatabase.cpp
@@ -833,6 +833,8 @@ bool OverlayCDB::setCompileCommand(PathRef File,
 std::unique_ptr<ProjectModules>
 OverlayCDB::getProjectModules(PathRef File) const {
   auto MDB = DelegatingCDB::getProjectModules(File);
+  if (!MDB)
+    return {};
   MDB->setCommandMangler([&Mangler = Mangler](tooling::CompileCommand &Command,
                                               PathRef CommandPath) {
     Mangler(Command, CommandPath);

``````````

</details>


https://github.com/llvm/llvm-project/pull/153802