Index: include/llvm/MC/MCParser/MCAsmParser.h
===================================================================
--- include/llvm/MC/MCParser/MCAsmParser.h
+++ include/llvm/MC/MCParser/MCAsmParser.h
@@ -258,7 +258,7 @@
 
 /// \brief Create an MCAsmParser instance.
 MCAsmParser *createMCAsmParser(SourceMgr &, MCContext &, MCStreamer &,
-                               const MCAsmInfo &);
+                               const MCAsmInfo &, unsigned CB = 0);
 
 } // End llvm namespace
 
Index: lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
@@ -124,10 +124,10 @@
     Buffer = MemoryBuffer::getMemBufferCopy(Str, "<inline asm>");
 
   // Tell SrcMgr about this buffer, it takes ownership of the buffer.
-  SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
+  unsigned BufNum = SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
 
   std::unique_ptr<MCAsmParser> Parser(
-      createMCAsmParser(SrcMgr, OutContext, *OutStreamer, *MAI));
+      createMCAsmParser(SrcMgr, OutContext, *OutStreamer, *MAI, BufNum));
 
   // We create a new MCInstrInfo here since we might be at the module level
   // and not have a MachineFunction to initialize the TargetInstrInfo from and
Index: lib/MC/MCParser/AsmParser.cpp
===================================================================
--- lib/MC/MCParser/AsmParser.cpp
+++ lib/MC/MCParser/AsmParser.cpp
@@ -209,7 +209,7 @@
 
 public:
   AsmParser(SourceMgr &SM, MCContext &Ctx, MCStreamer &Out,
-            const MCAsmInfo &MAI);
+            const MCAsmInfo &MAI, unsigned CB);
   ~AsmParser() override;
 
   bool Run(bool NoInitialTextSection, bool NoFinalize = false) override;
@@ -572,9 +572,9 @@
 enum { DEFAULT_ADDRSPACE = 0 };
 
 AsmParser::AsmParser(SourceMgr &SM, MCContext &Ctx, MCStreamer &Out,
-                     const MCAsmInfo &MAI)
+                     const MCAsmInfo &MAI, unsigned CB = 0)
     : Lexer(MAI), Ctx(Ctx), Out(Out), MAI(MAI), SrcMgr(SM),
-      PlatformParser(nullptr), CurBuffer(SM.getMainFileID()),
+      PlatformParser(nullptr), CurBuffer(CB ? CB : SM.getMainFileID()),
       MacrosEnabledFlag(true), CppHashInfo(), AssemblerDialect(~0U),
       IsDarwin(false), ParsingInlineAsm(false) {
   HadError = false;
@@ -5519,6 +5519,7 @@
 
 /// \brief Create an MCAsmParser instance.
 MCAsmParser *llvm::createMCAsmParser(SourceMgr &SM, MCContext &C,
-                                     MCStreamer &Out, const MCAsmInfo &MAI) {
-  return new AsmParser(SM, C, Out, MAI);
+                                     MCStreamer &Out, const MCAsmInfo &MAI,
+                                     unsigned CB) {
+  return new AsmParser(SM, C, Out, MAI, CB);
 }