rearrange MCContext ownership.  Before LLVMTargetMachine created it 
and passing off ownership to AsmPrinter.  Now MachineModuleInfo
creates it and owns it by value.  This allows us to use MCSymbols
more consistently throughout the rest of the code generator, and
simplifies a bit of code.  This also allows MachineFunction to 
keep an MCContext reference handy, and cleans up the TargetRegistry
interfaces for AsmPrinters.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98450 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 51e538e..75e45ef 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -13,16 +13,15 @@
 
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/PassManager.h"
-#include "llvm/Pass.h"
 #include "llvm/Analysis/Verifier.h"
 #include "llvm/Assembly/PrintModulePass.h"
 #include "llvm/CodeGen/AsmPrinter.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/MachineFunctionAnalysis.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/GCStrategy.h"
+#include "llvm/CodeGen/Passes.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/MC/MCAsmInfo.h"
-#include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Target/TargetRegistry.h"
@@ -116,11 +115,12 @@
                                             CodeGenOpt::Level OptLevel,
                                             bool DisableVerify) {
   // Add common CodeGen passes.
-  if (addCommonCodeGenPasses(PM, OptLevel, DisableVerify))
+  MCContext *Context = 0;
+  if (addCommonCodeGenPasses(PM, OptLevel, DisableVerify, Context))
     return true;
+  assert(Context != 0 && "Failed to get MCContext");
 
   const MCAsmInfo &MAI = *getMCAsmInfo();
-  OwningPtr<MCContext> Context(new MCContext(MAI));
   OwningPtr<MCStreamer> AsmStreamer;
 
   formatted_raw_ostream *LegacyOutput;
@@ -166,16 +166,14 @@
     break;
   }
   
-  // Create the AsmPrinter, which takes ownership of Context and AsmStreamer
-  // if successful.
+  // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
   FunctionPass *Printer =
-    getTarget().createAsmPrinter(*LegacyOutput, *this, *Context, *AsmStreamer,
-                                 getMCAsmInfo());
+    getTarget().createAsmPrinter(*LegacyOutput, *this, *AsmStreamer);
   if (Printer == 0)
     return true;
   
-  // If successful, createAsmPrinter took ownership of AsmStreamer and Context.
-  Context.take(); AsmStreamer.take();
+  // If successful, createAsmPrinter took ownership of AsmStreamer.
+  AsmStreamer.take();
   
   PM.add(Printer);
   
@@ -199,7 +197,8 @@
   setCodeModelForJIT();
   
   // Add common CodeGen passes.
-  if (addCommonCodeGenPasses(PM, OptLevel, DisableVerify))
+  MCContext *Ctx = 0;
+  if (addCommonCodeGenPasses(PM, OptLevel, DisableVerify, Ctx))
     return true;
 
   addCodeEmitter(PM, OptLevel, JCE);
@@ -208,8 +207,7 @@
   return false; // success!
 }
 
-static void printNoVerify(PassManagerBase &PM,
-                           const char *Banner) {
+static void printNoVerify(PassManagerBase &PM, const char *Banner) {
   if (PrintMachineCode)
     PM.add(createMachineFunctionPrinterPass(dbgs(), Banner));
 }
@@ -229,7 +227,8 @@
 ///
 bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM,
                                                CodeGenOpt::Level OptLevel,
-                                               bool DisableVerify) {
+                                               bool DisableVerify,
+                                               MCContext *&OutContext) {
   // Standard LLVM-Level Passes.
 
   // Before running any passes, run the verifier to determine if the input
@@ -252,8 +251,7 @@
 
   // Turn exception handling constructs into something the code generators can
   // handle.
-  switch (getMCAsmInfo()->getExceptionHandlingType())
-  {
+  switch (getMCAsmInfo()->getExceptionHandlingType()) {
   case ExceptionHandling::SjLj:
     // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both
     // Dwarf EH prepare needs to be run after SjLj prepare. Otherwise,
@@ -293,6 +291,13 @@
     PM.add(createVerifierPass());
 
   // Standard Lower-Level Passes.
+  
+  // Install a MachineModuleInfo class, which is an immutable pass that holds
+  // all the per-module stuff we're generating, including MCContext.
+  MachineModuleInfo *MMI = new MachineModuleInfo(*getMCAsmInfo());
+  PM.add(MMI);
+  OutContext = &MMI->getContext(); // Return the MCContext specifically by-ref.
+  
 
   // Set up a MachineFunction for the rest of CodeGen to work on.
   PM.add(new MachineFunctionAnalysis(*this, OptLevel));