Remove every uses of getGlobalContext() in LLVM (but the C API)

At the same time, fixes InstructionsTest::CastInst unittest: yes
you can leave the IR in an invalid state and exit when you don't
destroy the context (like the global one), no longer now.

This is the first part of http://reviews.llvm.org/D19094

From: Mehdi Amini <[email protected]>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@266379 91177308-0d34-0410-b5e6-96231b3b80d8

bindings/ocaml/llvm/llvm.mli

@@ -434,7 +434,7 @@ val create_context : unit -> llcontext
     [llvm::LLVMContext::~LLVMContext]. *)
 val dispose_context : llcontext -> unit
 
-(** See the function [llvm::getGlobalContext]. *)
+(** See the function [LLVMGetGlobalContext]. *)
 val global_context : unit -> llcontext
 
 (** [mdkind_id context name] returns the MDKind ID that corresponds to the

docs/ProgrammersManual.rst

@@ -2419,11 +2419,6 @@ determine what context they belong to by looking at their own ``Type``.  If you
 are adding new entities to LLVM IR, please try to maintain this interface
 design.
 
-For clients that do *not* require the benefits of isolation, LLVM provides a
-convenience API ``getGlobalContext()``.  This returns a global, lazily
-initialized ``LLVMContext`` that may be used in situations where isolation is
-not a concern.
-
 .. _jitthreading:
 
 Threads and the JIT

docs/ReleaseNotes.rst

@@ -38,6 +38,8 @@ Non-comprehensive list of changes in this release
   (other than GlobalValue). This is intended to be used in release builds by
   clients that are interested in saving CPU/memory as much as possible.
 
+* There is no longer a "global context" available in LLVM, except for the C API.
+
 * .. note about autoconf build having been removed.
 
 * .. note about C API functions LLVMParseBitcode,

docs/tutorial/LangImpl3.rst

@@ -74,7 +74,7 @@ parser, which will be used to report errors found during code generation
 .. code-block:: c++
 
     static std::unique_ptr<Module> *TheModule;
-    static IRBuilder<> Builder(getGlobalContext());
+    static IRBuilder<> Builder(LLVMContext);
     static std::map<std::string, Value*> NamedValues;
 
     Value *LogErrorV(const char *Str) {
@@ -116,7 +116,7 @@ First we'll do numeric literals:
 .. code-block:: c++
 
     Value *NumberExprAST::codegen() {
-      return ConstantFP::get(getGlobalContext(), APFloat(Val));
+      return ConstantFP::get(LLVMContext, APFloat(Val));
     }
 
 In the LLVM IR, numeric constants are represented with the
@@ -165,7 +165,7 @@ variables <LangImpl7.html#user-defined-local-variables>`_.
       case '<':
         L = Builder.CreateFCmpULT(L, R, "cmptmp");
         // Convert bool 0/1 to double 0.0 or 1.0
-        return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+        return Builder.CreateUIToFP(L, Type::getDoubleTy(LLVMContext),
                                     "booltmp");
       default:
         return LogErrorV("invalid binary operator");
@@ -264,9 +264,9 @@ with:
     Function *PrototypeAST::codegen() {
       // Make the function type:  double(double,double) etc.
       std::vector<Type*> Doubles(Args.size(),
-                                 Type::getDoubleTy(getGlobalContext()));
+                                 Type::getDoubleTy(LLVMContext));
       FunctionType *FT =
-        FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+        FunctionType::get(Type::getDoubleTy(LLVMContext), Doubles, false);
 
       Function *F =
         Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
@@ -340,7 +340,7 @@ assert that the function is empty (i.e. has no body yet) before we start.
 .. code-block:: c++
 
   // Create a new basic block to start insertion into.
-  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  BasicBlock *BB = BasicBlock::Create(LLVMContext, "entry", TheFunction);
   Builder.SetInsertPoint(BB);
 
   // Record the function arguments in the NamedValues map.

docs/tutorial/LangImpl4.rst

@@ -131,7 +131,8 @@ for us:
 
     void InitializeModuleAndPassManager(void) {
       // Open a new module.
-      TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+      Context LLVMContext;
+      TheModule = llvm::make_unique<Module>("my cool jit", LLVMContext);
       TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
 
       // Create a new pass manager attached to it.

docs/tutorial/LangImpl5.rst

@@ -292,7 +292,7 @@ for ``IfExprAST``:
 
       // Convert condition to a bool by comparing equal to 0.0.
       CondV = Builder.CreateFCmpONE(
-          CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+          CondV, ConstantFP::get(LLVMContext, APFloat(0.0)), "ifcond");
 
 This code is straightforward and similar to what we saw before. We emit
 the expression for the condition, then compare that value to zero to get
@@ -305,9 +305,9 @@ a truth value as a 1-bit (bool) value.
       // Create blocks for the then and else cases.  Insert the 'then' block at the
       // end of the function.
       BasicBlock *ThenBB =
-          BasicBlock::Create(getGlobalContext(), "then", TheFunction);
-      BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
-      BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
+          BasicBlock::Create(LLVMContext, "then", TheFunction);
+      BasicBlock *ElseBB = BasicBlock::Create(LLVMContext, "else");
+      BasicBlock *MergeBB = BasicBlock::Create(LLVMContext, "ifcont");
 
       Builder.CreateCondBr(CondV, ThenBB, ElseBB);
 
@@ -400,7 +400,7 @@ code:
       TheFunction->getBasicBlockList().push_back(MergeBB);
       Builder.SetInsertPoint(MergeBB);
       PHINode *PN =
-        Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+        Builder.CreatePHI(Type::getDoubleTy(LLVMContext), 2, "iftmp");
 
       PN->addIncoming(ThenV, ThenBB);
       PN->addIncoming(ElseV, ElseBB);
@@ -625,7 +625,7 @@ expression).
       Function *TheFunction = Builder.GetInsertBlock()->getParent();
       BasicBlock *PreheaderBB = Builder.GetInsertBlock();
       BasicBlock *LoopBB =
-          BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+          BasicBlock::Create(LLVMContext, "loop", TheFunction);
 
       // Insert an explicit fall through from the current block to the LoopBB.
       Builder.CreateBr(LoopBB);
@@ -642,7 +642,7 @@ the two blocks.
       Builder.SetInsertPoint(LoopBB);
 
       // Start the PHI node with an entry for Start.
-      PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()),
+      PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(LLVMContext),
                                             2, VarName.c_str());
       Variable->addIncoming(StartVal, PreheaderBB);
 
@@ -693,7 +693,7 @@ table.
           return nullptr;
       } else {
         // If not specified, use 1.0.
-        StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+        StepVal = ConstantFP::get(LLVMContext, APFloat(1.0));
       }
 
       Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
@@ -712,7 +712,7 @@ iteration of the loop.
 
       // Convert condition to a bool by comparing equal to 0.0.
       EndCond = Builder.CreateFCmpONE(
-          EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+          EndCond, ConstantFP::get(LLVMContext, APFloat(0.0)), "loopcond");
 
 Finally, we evaluate the exit value of the loop, to determine whether
 the loop should exit. This mirrors the condition evaluation for the
@@ -723,7 +723,7 @@ if/then/else statement.
       // Create the "after loop" block and insert it.
       BasicBlock *LoopEndBB = Builder.GetInsertBlock();
       BasicBlock *AfterBB =
-          BasicBlock::Create(getGlobalContext(), "afterloop", TheFunction);
+          BasicBlock::Create(LLVMContext, "afterloop", TheFunction);
 
       // Insert the conditional branch into the end of LoopEndBB.
       Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
@@ -751,7 +751,7 @@ insertion position to it.
         NamedValues.erase(VarName);
 
       // for expr always returns 0.0.
-      return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+      return Constant::getNullValue(Type::getDoubleTy(LLVMContext));
     }
 
 The final code handles various cleanups: now that we have the "NextVar"

docs/tutorial/LangImpl6.rst

@@ -251,7 +251,7 @@ default case for our existing binary operator node:
       case '<':
         L = Builder.CreateFCmpULT(L, R, "cmptmp");
         // Convert bool 0/1 to double 0.0 or 1.0
-        return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
+        return Builder.CreateUIToFP(L, Type::getDoubleTy(LLVMContext),
                                     "booltmp");
       default:
         break;
@@ -288,7 +288,7 @@ The final piece of code we are missing, is a bit of top-level magic:
         BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
 
       // Create a new basic block to start insertion into.
-      BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+      BasicBlock *BB = BasicBlock::Create(LLVMContext, "entry", TheFunction);
       Builder.SetInsertPoint(BB);
 
       if (Value *RetVal = Body->codegen()) {

docs/tutorial/LangImpl7.rst

@@ -339,7 +339,7 @@ the function:
                                               const std::string &VarName) {
       IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
                      TheFunction->getEntryBlock().begin());
-      return TmpB.CreateAlloca(Type::getDoubleTy(getGlobalContext()), 0,
+      return TmpB.CreateAlloca(Type::getDoubleTy(LLVMContext), 0,
                                VarName.c_str());
     }
 
@@ -812,7 +812,7 @@ previous value that we replace in OldBindings.
           if (!InitVal)
             return nullptr;
         } else { // If not specified, use 0.0.
-          InitVal = ConstantFP::get(getGlobalContext(), APFloat(0.0));
+          InitVal = ConstantFP::get(LLVMContext, APFloat(0.0));
         }
 
         AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);

examples/BrainF/BrainFDriver.cpp

@@ -88,7 +88,7 @@ void addMainFunction(Module *mod) {
 int main(int argc, char **argv) {
   cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
 
-  LLVMContext &Context = getGlobalContext();
+  LLVMContext Context;
 
   if (InputFilename == "") {
     errs() << "Error: You must specify the filename of the program to "

examples/ExceptionDemo/ExceptionDemo.cpp

@@ -1951,12 +1951,12 @@ int main(int argc, char *argv[]) {
 
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmPrinter();
-  llvm::LLVMContext &context = llvm::getGlobalContext();
-  llvm::IRBuilder<> theBuilder(context);
+  llvm::LLVMContext Context;
+  llvm::IRBuilder<> theBuilder(Context);
 
   // Make the module, which holds all the code.
   std::unique_ptr<llvm::Module> Owner =
-      llvm::make_unique<llvm::Module>("my cool jit", context);
+      llvm::make_unique<llvm::Module>("my cool jit", Context);
   llvm::Module *module = Owner.get();
 
   std::unique_ptr<llvm::RTDyldMemoryManager> MemMgr(new llvm::SectionMemoryManager());

examples/Kaleidoscope/Chapter3/toy.cpp

@@ -381,7 +381,8 @@ static std::unique_ptr<PrototypeAST> ParseExtern() {
 //===----------------------------------------------------------------------===//
 
 static std::unique_ptr<Module> TheModule;
-static IRBuilder<> Builder(getGlobalContext());
+static LLVMContext TheContext;
+static IRBuilder<> Builder(TheContext);
 static std::map<std::string, Value *> NamedValues;
 
 Value *LogErrorV(const char *Str) {
@@ -390,7 +391,7 @@ Value *LogErrorV(const char *Str) {
 }
 
 Value *NumberExprAST::codegen() {
-  return ConstantFP::get(getGlobalContext(), APFloat(Val));
+  return ConstantFP::get(TheContext, APFloat(Val));
 }
 
 Value *VariableExprAST::codegen() {
@@ -417,8 +418,7 @@ Value *BinaryExprAST::codegen() {
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
-    return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
-                                "booltmp");
+    return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");
   default:
     return LogErrorV("invalid binary operator");
   }
@@ -446,10 +446,9 @@ Value *CallExprAST::codegen() {
 
 Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type *> Doubles(Args.size(),
-                              Type::getDoubleTy(getGlobalContext()));
+  std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));
   FunctionType *FT =
-      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+      FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
 
   Function *F =
       Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
@@ -473,7 +472,7 @@ Function *FunctionAST::codegen() {
     return nullptr;
 
   // Create a new basic block to start insertion into.
-  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
   Builder.SetInsertPoint(BB);
 
   // Record the function arguments in the NamedValues map.
@@ -577,7 +576,7 @@ int main() {
   getNextToken();
 
   // Make the module, which holds all the code.
-  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule = llvm::make_unique<Module>("my cool jit", TheContext);
 
   // Run the main "interpreter loop" now.
   MainLoop();

examples/Kaleidoscope/Chapter4/toy.cpp

@@ -388,7 +388,8 @@ static std::unique_ptr<PrototypeAST> ParseExtern() {
 //===----------------------------------------------------------------------===//
 
 static std::unique_ptr<Module> TheModule;
-static IRBuilder<> Builder(getGlobalContext());
+static LLVMContext TheContext;
+static IRBuilder<> Builder(TheContext);
 static std::map<std::string, Value *> NamedValues;
 static std::unique_ptr<legacy::FunctionPassManager> TheFPM;
 static std::unique_ptr<KaleidoscopeJIT> TheJIT;
@@ -415,7 +416,7 @@ Function *getFunction(std::string Name) {
 }
 
 Value *NumberExprAST::codegen() {
-  return ConstantFP::get(getGlobalContext(), APFloat(Val));
+  return ConstantFP::get(TheContext, APFloat(Val));
 }
 
 Value *VariableExprAST::codegen() {
@@ -442,8 +443,7 @@ Value *BinaryExprAST::codegen() {
   case '<':
     L = Builder.CreateFCmpULT(L, R, "cmptmp");
     // Convert bool 0/1 to double 0.0 or 1.0
-    return Builder.CreateUIToFP(L, Type::getDoubleTy(getGlobalContext()),
-                                "booltmp");
+    return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext), "booltmp");
   default:
     return LogErrorV("invalid binary operator");
   }
@@ -471,10 +471,9 @@ Value *CallExprAST::codegen() {
 
 Function *PrototypeAST::codegen() {
   // Make the function type:  double(double,double) etc.
-  std::vector<Type *> Doubles(Args.size(),
-                              Type::getDoubleTy(getGlobalContext()));
+  std::vector<Type *> Doubles(Args.size(), Type::getDoubleTy(TheContext));
   FunctionType *FT =
-      FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+      FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
 
   Function *F =
       Function::Create(FT, Function::ExternalLinkage, Name, TheModule.get());
@@ -497,7 +496,7 @@ Function *FunctionAST::codegen() {
     return nullptr;
 
   // Create a new basic block to start insertion into.
-  BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+  BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
   Builder.SetInsertPoint(BB);
 
   // Record the function arguments in the NamedValues map.
@@ -529,7 +528,7 @@ Function *FunctionAST::codegen() {
 
 static void InitializeModuleAndPassManager() {
   // Open a new module.
-  TheModule = llvm::make_unique<Module>("my cool jit", getGlobalContext());
+  TheModule = llvm::make_unique<Module>("my cool jit", TheContext);
   TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
 
   // Create a new pass manager attached to it.