Fix a couple issues with the JIT and multiple modules:

1. The "JITState" object creates a PassManager with the ModuleProvider that the
   jit is created with.  If the ModuleProvider is removed and deleted, the
   PassManager is invalid.

2. The Global maps in the JIT were not invalidated with a ModuleProvider was 
   removed.  This could lead to a case where the Module would be freed, and a 
   new Module with Globals at the same addresses could return invalid results.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51384 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 535f4ac..8b94ad0 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -59,6 +59,7 @@
     ModuleProvider *MP = *I;
     if (MP == P) {
       Modules.erase(I);
+      clearGlobalMappingsFromModule(MP->getModule());
       return MP->releaseModule(ErrInfo);
     }
   }
@@ -106,6 +107,22 @@
   state.getGlobalAddressReverseMap(locked).clear();
 }
 
+/// clearGlobalMappingsFromModule - Clear all global mappings that came from a
+/// particular module, because it has been removed from the JIT.
+void ExecutionEngine::clearGlobalMappingsFromModule(Module *M) {
+  MutexGuard locked(lock);
+  
+  for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
+    state.getGlobalAddressMap(locked).erase(FI);
+    state.getGlobalAddressReverseMap(locked).erase(FI);
+  }
+  for (Module::global_iterator GI = M->global_begin(), GE = M->global_end(); 
+       GI != GE; ++GI) {
+    state.getGlobalAddressMap(locked).erase(GI);
+    state.getGlobalAddressReverseMap(locked).erase(GI);
+  }
+}
+
 /// updateGlobalMapping - Replace an existing mapping for GV with a new
 /// address.  This updates both maps as required.  If "Addr" is null, the
 /// entry for the global is removed from the mappings.
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index 4b888ef..48286e9 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -91,15 +91,17 @@
 
 JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
          JITMemoryManager *JMM)
-  : ExecutionEngine(MP), TM(tm), TJI(tji), jitstate(MP) {
+  : ExecutionEngine(MP), TM(tm), TJI(tji) {
   setTargetData(TM.getTargetData());
 
+  jitstate = new JITState(MP);
+
   // Initialize MCE
   MCE = createEmitter(*this, JMM);
 
   // Add target data
   MutexGuard locked(lock);
-  FunctionPassManager &PM = jitstate.getPM(locked);
+  FunctionPassManager &PM = jitstate->getPM(locked);
   PM.add(new TargetData(*TM.getTargetData()));
 
   // Turn the machine code intermediate representation into bytes in memory that
@@ -114,10 +116,54 @@
 }
 
 JIT::~JIT() {
+  delete jitstate;
   delete MCE;
   delete &TM;
 }
 
+/// addModuleProvider - Add a new ModuleProvider to the JIT.  If we previously
+/// removed the last ModuleProvider, we need re-initialize jitstate with a valid
+/// ModuleProvider.
+void JIT::addModuleProvider(ModuleProvider *MP) {
+  MutexGuard locked(lock);
+
+  if (Modules.empty()) {
+    assert(!jitstate && "jitstate should be NULL if Modules vector is empty!");
+
+    jitstate = new JITState(MP);
+
+    FunctionPassManager &PM = jitstate->getPM(locked);
+    PM.add(new TargetData(*TM.getTargetData()));
+
+    // Turn the machine code intermediate representation into bytes in memory
+    // that may be executed.
+    if (TM.addPassesToEmitMachineCode(PM, *MCE, false /*fast*/)) {
+      cerr << "Target does not support machine code emission!\n";
+      abort();
+    }
+    
+    // Initialize passes.
+    PM.doInitialization();
+  }
+  
+  ExecutionEngine::addModuleProvider(MP);
+}
+
+/// removeModuleProvider - If we are removing the last ModuleProvider, 
+/// invalidate the jitstate since the PassManager it contains references a
+/// released ModuleProvider.
+Module *JIT::removeModuleProvider(ModuleProvider *MP, std::string *E) {
+  Module *result = ExecutionEngine::removeModuleProvider(MP, E);
+  
+  MutexGuard locked(lock);
+  if (Modules.empty()) {
+    delete jitstate;
+    jitstate = 0;
+  }
+  
+  return result;
+}
+
 /// run - Start execution with the specified function and arguments.
 ///
 GenericValue JIT::runFunction(Function *F,
@@ -289,15 +335,15 @@
 
   // JIT the function
   isAlreadyCodeGenerating = true;
-  jitstate.getPM(locked).run(*F);
+  jitstate->getPM(locked).run(*F);
   isAlreadyCodeGenerating = false;
 
   // If the function referred to a global variable that had not yet been
   // emitted, it allocates memory for the global, but doesn't emit it yet.  Emit
   // all of these globals now.
-  while (!jitstate.getPendingGlobals(locked).empty()) {
-    const GlobalVariable *GV = jitstate.getPendingGlobals(locked).back();
-    jitstate.getPendingGlobals(locked).pop_back();
+  while (!jitstate->getPendingGlobals(locked).empty()) {
+    const GlobalVariable *GV = jitstate->getPendingGlobals(locked).back();
+    jitstate->getPendingGlobals(locked).pop_back();
     EmitGlobalVariable(GV);
   }
 }
@@ -387,7 +433,7 @@
       unsigned MisAligned = ((intptr_t)Ptr & (A-1));
       Ptr = (char*)Ptr + (MisAligned ? (A-MisAligned) : 0);
     }
-    jitstate.getPendingGlobals(locked).push_back(GV);
+    jitstate->getPendingGlobals(locked).push_back(GV);
   }
   addGlobalMapping(GV, Ptr);
   return Ptr;
diff --git a/lib/ExecutionEngine/JIT/JIT.h b/lib/ExecutionEngine/JIT/JIT.h
index 69e301b..7366f94 100644
--- a/lib/ExecutionEngine/JIT/JIT.h
+++ b/lib/ExecutionEngine/JIT/JIT.h
@@ -54,7 +54,7 @@
   TargetJITInfo &TJI;      // The JITInfo for the target we are compiling to
   MachineCodeEmitter *MCE; // MCE object
 
-  JITState jitstate;
+  JITState *jitstate;
 
   JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji, 
       JITMemoryManager *JMM);
@@ -76,6 +76,10 @@
     return createJIT(MP, Err, 0);
   }
 
+  virtual void addModuleProvider(ModuleProvider *MP);
+  virtual Module *removeModuleProvider(ModuleProvider *MP,
+                                       std::string *ErrInfo = 0);
+
   /// run - Start execution with the specified function and arguments.
   ///
   virtual GenericValue runFunction(Function *F,