3 files changed, 27 insertions, 11 deletions
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index fffa9045b2fd..95987fac74e1 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -28,8 +28,8 @@
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallingConv.h"
 #include "llvm/IR/CallSite.h"
+#include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Comdat.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
@@ -40,13 +40,13 @@
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/GVMaterializer.h"
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalIFunc.h"
 #include "llvm/IR/GlobalIndirectSymbol.h"
 #include "llvm/IR/GlobalObject.h"
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/GVMaterializer.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/InstrTypes.h"
@@ -5370,12 +5370,20 @@ static Expected<StringRef> readStrtab(BitstreamCursor &Stream) {
 
 Expected<std::vector<BitcodeModule>>
 llvm::getBitcodeModuleList(MemoryBufferRef Buffer) {
+  auto FOrErr = getBitcodeFileContents(Buffer);
+  if (!FOrErr)
+    return FOrErr.takeError();
+  return std::move(FOrErr->Mods);
+}
+
+Expected<BitcodeFileContents>
+llvm::getBitcodeFileContents(MemoryBufferRef Buffer) {
   Expected<BitstreamCursor> StreamOrErr = initStream(Buffer);
   if (!StreamOrErr)
     return StreamOrErr.takeError();
   BitstreamCursor &Stream = *StreamOrErr;
 
-  std::vector<BitcodeModule> Modules;
+  BitcodeFileContents F;
   while (true) {
     uint64_t BCBegin = Stream.getCurrentByteNo();
 
@@ -5383,7 +5391,7 @@ llvm::getBitcodeModuleList(MemoryBufferRef Buffer) {
     // of the bitcode stream (e.g. Apple's ar tool). If we are close enough to
     // the end that there cannot possibly be another module, stop looking.
     if (BCBegin + 8 >= Stream.getBitcodeBytes().size())
-      return Modules;
+      return F;
 
     BitstreamEntry Entry = Stream.advance();
     switch (Entry.Kind) {
@@ -5409,10 +5417,10 @@ llvm::getBitcodeModuleList(MemoryBufferRef Buffer) {
         if (Stream.SkipBlock())
           return error("Malformed block");
 
-        Modules.push_back({Stream.getBitcodeBytes().slice(
-                               BCBegin, Stream.getCurrentByteNo() - BCBegin),
-                           Buffer.getBufferIdentifier(), IdentificationBit,
-                           ModuleBit});
+        F.Mods.push_back({Stream.getBitcodeBytes().slice(
+                              BCBegin, Stream.getCurrentByteNo() - BCBegin),
+                          Buffer.getBufferIdentifier(), IdentificationBit,
+                          ModuleBit});
         continue;
       }
 
@@ -5424,7 +5432,7 @@ llvm::getBitcodeModuleList(MemoryBufferRef Buffer) {
         // not have its own string table. A bitcode file may have multiple
         // string tables if it was created by binary concatenation, for example
         // with "llvm-cat -b".
-        for (auto I = Modules.rbegin(), E = Modules.rend(); I != E; ++I) {
+        for (auto I = F.Mods.rbegin(), E = F.Mods.rend(); I != E; ++I) {
           if (!I->Strtab.empty())
             break;
           I->Strtab = *Strtab;
diff --git a/lib/Bitcode/Reader/MetadataLoader.cpp b/lib/Bitcode/Reader/MetadataLoader.cpp
index d80e1da911ca..ee2fe2a0cc18 100644
--- a/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -53,8 +53,8 @@
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
-#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/ModuleSummaryIndex.h"
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index 9043b8c12d25..d5879fec95cb 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -3305,7 +3305,15 @@ static const uint64_t INDEX_VERSION = 3;
 /// Emit the per-module summary section alongside the rest of
 /// the module's bitcode.
 void ModuleBitcodeWriter::writePerModuleGlobalValueSummary() {
-  Stream.EnterSubblock(bitc::GLOBALVAL_SUMMARY_BLOCK_ID, 4);
+  // By default we compile with ThinLTO if the module has a summary, but the
+  // client can request full LTO with a module flag.
+  bool IsThinLTO = true;
+  if (auto *MD =
+          mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("ThinLTO")))
+    IsThinLTO = MD->getZExtValue();
+  Stream.EnterSubblock(IsThinLTO ? bitc::GLOBALVAL_SUMMARY_BLOCK_ID
+                                 : bitc::FULL_LTO_GLOBALVAL_SUMMARY_BLOCK_ID,
+                       4);
 
   Stream.EmitRecord(bitc::FS_VERSION, ArrayRef<uint64_t>{INDEX_VERSION});