[Modules] Improve diagnostics for incomplete umbrella

One of the -Wincomplete-umbrella warnings diagnoses when a header is present in
the directory but it's not present in the umbrella header. Currently, this
warning only happens on top level modules; any submodule using an umbrella
header does not get this warning. Fix that by also considering the submodules.

Differential Revision: https://reviews.llvm.org/D32576

rdar://problem/22623686

llvm-svn: 301597

1 files changed, 17 insertions, 4 deletions

diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 9f68f3bb89d..fcc49b38703 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -287,6 +287,14 @@ const char *Preprocessor::getCurLexerEndPos() {
   return EndPos;
 }
 
+static void collectAllSubModulesWithUmbrellaHeader(
+    const Module &Mod, SmallVectorImpl<const Module *> &SubMods) {
+  if (Mod.getUmbrellaHeader())
+    SubMods.push_back(&Mod);
+  for (auto *M : Mod.submodules())
+    collectAllSubModulesWithUmbrellaHeader(*M, SubMods);
+}
+
 void Preprocessor::diagnoseMissingHeaderInUmbrellaDir(const Module &Mod) {
   assert(Mod.getUmbrellaHeader() && "Module must use umbrella header");
   SourceLocation StartLoc =
@@ -507,10 +515,15 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
   }
 
   // If we are building a module that has an umbrella header, make sure that
-  // each of the headers within the directory covered by the umbrella header
-  // was actually included by the umbrella header.
-  if (Module *Mod = getCurrentModule())
-    diagnoseMissingHeaderInUmbrellaDir(*Mod);
+  // each of the headers within the directory, including all submodules, is
+  // covered by the umbrella header was actually included by the umbrella
+  // header.
+  if (Module *Mod = getCurrentModule()) {
+    llvm::SmallVector<const Module *, 4> AllMods;
+    collectAllSubModulesWithUmbrellaHeader(*Mod, AllMods);
+    for (auto *M : AllMods)
+      diagnoseMissingHeaderInUmbrellaDir(*M);
+  }
 
   return true;
 }