[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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@301597 91177308-0d34-0410-b5e6-96231b3b80d8

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;
 }

test/Modules/Inputs/incomplete-umbrella/Foo.framework/Headers/Bar.h

@@ -0,0 +1 @@
+#define BAR_PUBLIC 1

test/Modules/Inputs/incomplete-umbrella/Foo.framework/Headers/FooPublic.h

@@ -0,0 +1 @@
+// FooPublic.h

test/Modules/Inputs/incomplete-umbrella/Foo.framework/Modules/module.modulemap

@@ -0,0 +1,5 @@
+framework module Foo {
+    umbrella header "FooPublic.h"
+    requires objc
+    export *
+}

test/Modules/Inputs/incomplete-umbrella/Foo.framework/Modules/module.private.modulemap

@@ -0,0 +1,5 @@
+explicit module Foo.Private {
+    umbrella header "Foo.h"
+    requires objc
+    export *
+}

test/Modules/Inputs/incomplete-umbrella/Foo.framework/PrivateHeaders/Baz.h

@@ -0,0 +1 @@
+#define BAZ_PRIVATE 1

test/Modules/Inputs/incomplete-umbrella/Foo.framework/PrivateHeaders/Foo.h

@@ -0,0 +1 @@
+// Foo.h

test/Modules/incomplete-umbrella.m

@@ -0,0 +1,15 @@
+// RUN: rm -rf %t
+// RUN: not %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t -F%S/Inputs/incomplete-umbrella -fsyntax-only %s 2>&1 | FileCheck %s
+
+#import <Foo/Foo.h>
+#import <Foo/Bar.h>
+#import <Foo/Baz.h>
+@import Foo.Private;
+
+// CHECK: warning: umbrella header for module 'Foo' does not include header 'Bar.h'
+// CHECK: warning: umbrella header for module 'Foo.Private' does not include header 'Baz.h'
+int foo() {
+  int a = BAR_PUBLIC;
+  int b = BAZ_PRIVATE;
+  return 0;
+}