From c15da610ac7f74bbac57c8b14388cd7684e5ed5a Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Fri, 18 Sep 2015 23:01:45 +0000
Subject: [PATCH] CGDebugInfo: Make creating a skeleton CU in
 getOrCreateModuleRef optional. We don't want a skeleton CU when generating
 debug info for the module itself.

NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@248062 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGDebugInfo.cpp | 35 +++++++++++++++++++++--------------
 lib/CodeGen/CGDebugInfo.h   |  6 ++++--
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 0b44e93c5c..723e8ffde3 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1673,7 +1673,8 @@ llvm::DIType *CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
 }
 
 llvm::DIModule *
-CGDebugInfo::getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod) {
+CGDebugInfo::getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod,
+                                  bool CreateSkeletonCU) {
   auto &ModRef = ModuleRefCache[Mod.ModuleName];
   if (ModRef)
     return cast<llvm::DIModule>(ModRef);
@@ -1700,15 +1701,20 @@ CGDebugInfo::getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod) {
       OS << '\"';
     }
   }
-  llvm::DIBuilder DIB(CGM.getModule());
-  auto *CU = DIB.createCompileUnit(TheCU->getSourceLanguage(), Mod.ModuleName,
-                                   Mod.Path, TheCU->getProducer(), true,
-                                   StringRef(), 0, Mod.ASTFile,
-                                   llvm::DIBuilder::FullDebug, Mod.Signature);
-  llvm::DIModule *M =
-      DIB.createModule(CU, Mod.ModuleName, ConfigMacros, Mod.Path,
-                       CGM.getHeaderSearchOpts().Sysroot);
-  DIB.finalize();
+
+  llvm::DIModule *M = nullptr;
+  if (CreateSkeletonCU) {
+    llvm::DIBuilder DIB(CGM.getModule());
+    auto *CU = DIB.createCompileUnit(TheCU->getSourceLanguage(), Mod.ModuleName,
+                                     Mod.Path, TheCU->getProducer(), true,
+                                     StringRef(), 0, Mod.ASTFile,
+                                     llvm::DIBuilder::FullDebug, Mod.Signature);
+    M = DIB.createModule(CU, Mod.ModuleName, ConfigMacros, Mod.Path,
+                         CGM.getHeaderSearchOpts().Sysroot);
+    DIB.finalize();
+  } else
+    M = DBuilder.createModule(TheCU, Mod.ModuleName, ConfigMacros, Mod.Path,
+                              CGM.getHeaderSearchOpts().Sysroot);
   ModRef.reset(M);
   return M;
 }
@@ -2158,12 +2164,13 @@ llvm::DIModule *CGDebugInfo::getParentModuleOrNull(const Decl *D) {
   if (!DebugTypeExtRefs || !D->isFromASTFile())
     return nullptr;
 
+  // Record a reference to an imported clang module or precompiled header.
   llvm::DIModule *ModuleRef = nullptr;
   auto *Reader = CGM.getContext().getExternalSource();
   auto Idx = D->getOwningModuleID();
   auto Info = Reader->getSourceDescriptor(Idx);
   if (Info)
-    ModuleRef = getOrCreateModuleRef(*Info);
+    ModuleRef = getOrCreateModuleRef(*Info, true);
   return ModuleRef;
 }
 
@@ -3387,9 +3394,9 @@ void CGDebugInfo::EmitImportDecl(const ImportDecl &ID) {
   auto *Reader = CGM.getContext().getExternalSource();
   auto Info = Reader->getSourceDescriptor(*ID.getImportedModule());
   DBuilder.createImportedDeclaration(
-    getCurrentContextDescriptor(cast<Decl>(ID.getDeclContext())),
-                                getOrCreateModuleRef(Info),
-                                getLineNumber(ID.getLocation()));
+      getCurrentContextDescriptor(cast<Decl>(ID.getDeclContext())),
+      getOrCreateModuleRef(Info, DebugTypeExtRefs),
+      getLineNumber(ID.getLocation()));
 }
 
 llvm::DIImportedEntity *
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index 72c6779178..8d42f57a3e 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -403,9 +403,11 @@ private:
   /// Get the type from the cache or create a new type if necessary.
   llvm::DIType *getOrCreateType(QualType Ty, llvm::DIFile *Fg);
 
-  /// Get a reference to a clang module.
+  /// Get a reference to a clang module.  If \p CreateSkeletonCU is true,
+  /// this also creates a split dwarf skeleton compile unit.
   llvm::DIModule *
-  getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod);
+  getOrCreateModuleRef(ExternalASTSource::ASTSourceDescriptor Mod,
+                       bool CreateSkeletonCU);
 
   /// DebugTypeExtRefs: If \p D originated in a clang module, return it.
   llvm::DIModule *getParentModuleOrNull(const Decl *D);
-- 
2.40.0