From f049e07eb8930214941c72f8e4409df394de1567 Mon Sep 17 00:00:00 2001
From: Nate Begeman <natebegeman@mac.com>
Date: Wed, 21 May 2008 16:34:48 +0000
Subject: [PATCH] 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
---
 .../llvm/ExecutionEngine/ExecutionEngine.h    |  9 ++-
 lib/ExecutionEngine/ExecutionEngine.cpp       | 17 ++++++
 lib/ExecutionEngine/JIT/JIT.cpp               | 60 ++++++++++++++++---
 lib/ExecutionEngine/JIT/JIT.h                 |  6 +-
 4 files changed, 82 insertions(+), 10 deletions(-)

diff --git a/include/llvm/ExecutionEngine/ExecutionEngine.h b/include/llvm/ExecutionEngine/ExecutionEngine.h
index ff584733eec..1159971a45b 100644
--- a/include/llvm/ExecutionEngine/ExecutionEngine.h
+++ b/include/llvm/ExecutionEngine/ExecutionEngine.h
@@ -126,7 +126,7 @@ public:
   /// addModuleProvider - Add a ModuleProvider to the list of modules that we
   /// can JIT from.  Note that this takes ownership of the ModuleProvider: when
   /// the ExecutionEngine is destroyed, it destroys the MP as well.
-  void addModuleProvider(ModuleProvider *P) {
+  virtual void addModuleProvider(ModuleProvider *P) {
     Modules.push_back(P);
   }
   
@@ -137,7 +137,8 @@ public:
 
   /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
   /// Release module from ModuleProvider.
-  Module* removeModuleProvider(ModuleProvider *P, std::string *ErrInfo = 0);
+  virtual Module* removeModuleProvider(ModuleProvider *P,
+                                       std::string *ErrInfo = 0);
 
   /// FindFunctionNamed - Search all of the active modules to find the one that
   /// defines FnName.  This is very slow operation and shouldn't be used for
@@ -174,6 +175,10 @@ public:
   /// use in dynamic compilation scenarios when you want to move globals
   void clearAllGlobalMappings();
   
+  /// clearGlobalMappingsFromModule - Clear all global mappings that came from a
+  /// particular module, because it has been removed from the JIT.
+  void clearGlobalMappingsFromModule(Module *M);
+  
   /// 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.  This returns the old
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 535f4ac90f7..8b94ad02840 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -59,6 +59,7 @@ Module* ExecutionEngine::removeModuleProvider(ModuleProvider *P,
     ModuleProvider *MP = *I;
     if (MP == P) {
       Modules.erase(I);
+      clearGlobalMappingsFromModule(MP->getModule());
       return MP->releaseModule(ErrInfo);
     }
   }
@@ -106,6 +107,22 @@ void ExecutionEngine::clearAllGlobalMappings() {
   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 4b888ef018c..48286e915ee 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -91,15 +91,17 @@ ExecutionEngine *ExecutionEngine::createJIT(ModuleProvider *MP,
 
 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(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
 }
 
 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 @@ void JIT::runJITOnFunction(Function *F) {
 
   // 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 @@ void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
       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 69e301bf6d0..7366f944365 100644
--- a/lib/ExecutionEngine/JIT/JIT.h
+++ b/lib/ExecutionEngine/JIT/JIT.h
@@ -54,7 +54,7 @@ class JIT : public ExecutionEngine {
   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 @@ public:
     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,