Add a function for profiling to run at shutdown. Unlike the existing API, this

can be used even when main() isn't present in the Module, but it means that you
don't get to read argv[].

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129163 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/ProfilingUtils.cpp b/lib/Transforms/Instrumentation/ProfilingUtils.cpp
index b57bbf60a07ab051db08ec803727bd30794d1a07..26b01e8c2fd3402c54095c4e12778ee360f4c65a 100644 (file)
--- a/lib/Transforms/Instrumentation/ProfilingUtils.cpp
+++ b/lib/Transforms/Instrumentation/ProfilingUtils.cpp
@@ -121,8 +121,7 @@ void llvm::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
   Indices[0] = Constant::getNullValue(Type::getInt32Ty(Context));
   Indices[1] = ConstantInt::get(Type::getInt32Ty(Context), CounterNum);
   Constant *ElementPtr =
-    ConstantExpr::getGetElementPtr(CounterArray, &Indices[0],
-                                          Indices.size());
+    ConstantExpr::getGetElementPtr(CounterArray, &Indices[0], Indices.size());
 
   // Load, increment and store the value back.
   Value *OldVal = new LoadInst(ElementPtr, "OldFuncCounter", InsertPos);
@@ -131,3 +130,39 @@ void llvm::IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
                                          "NewFuncCounter", InsertPos);
   new StoreInst(NewVal, ElementPtr, InsertPos);
 }
+
+void llvm::InsertProfilingShutdownCall(Function *Callee, Module *Mod) {
+  // llvm.global_dtors is an array of type { i32, void ()* }. Prepare those
+  // types.
+  const Type *GlobalDtorElems[2] = {
+    Type::getInt32Ty(Mod->getContext()),
+    FunctionType::get(Type::getVoidTy(Mod->getContext()), false)->getPointerTo()
+  };
+  const StructType *GlobalDtorElemTy =
+      StructType::get(Mod->getContext(), GlobalDtorElems, false);
+
+  // Construct the new element we'll be adding.
+  Constant *Elem[2] = {
+    ConstantInt::get(Type::getInt32Ty(Mod->getContext()), 65535),
+    ConstantExpr::getBitCast(Callee, GlobalDtorElems[1])
+  };
+
+  // If llvm.global_dtors exists, make a copy of the things in its list and
+  // delete it, to replace it with one that has a larger array type.
+  std::vector<Constant *> dtors;
+  if (GlobalVariable *GlobalDtors = Mod->getNamedGlobal("llvm.global_dtors")) {
+    ConstantArray *InitList =
+        cast<ConstantArray>(GlobalDtors->getInitializer());
+    for (unsigned i = 0, e = InitList->getType()->getNumElements(); i != e; ++i)
+      dtors.push_back(cast<Constant>(InitList->getOperand(i)));
+    GlobalDtors->eraseFromParent();
+  }
+
+  // Build up llvm.global_dtors with our new item in it.
+  GlobalVariable *GlobalDtors = new GlobalVariable(
+      *Mod, ArrayType::get(GlobalDtorElemTy, 1), false,
+      GlobalValue::AppendingLinkage, NULL, "llvm.global_dtors");
+  dtors.push_back(ConstantStruct::get(Mod->getContext(), Elem, 2, false));
+  GlobalDtors->setInitializer(ConstantArray::get(
+      cast<ArrayType>(GlobalDtors->getType()->getElementType()), dtors));
+}

diff --git a/lib/Transforms/Instrumentation/ProfilingUtils.h b/lib/Transforms/Instrumentation/ProfilingUtils.h
index a76e3576e1ca24b854fa2cecae4ca9c76d470fd7..09b22171ff04d6cf9a9ee3ef346012de1f761ef5 100644 (file)
--- a/lib/Transforms/Instrumentation/ProfilingUtils.h
+++ b/lib/Transforms/Instrumentation/ProfilingUtils.h
@@ -18,9 +18,10 @@
 #define PROFILINGUTILS_H
 
 namespace llvm {
+  class BasicBlock;
   class Function;
   class GlobalValue;
-  class BasicBlock;
+  class Module;
   class PointerType;
 
   void InsertProfilingInitCall(Function *MainFn, const char *FnName,
@@ -29,6 +30,7 @@ namespace llvm {
   void IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,
                                GlobalValue *CounterArray,
                                bool beginning = true);
+  void InsertProfilingShutdownCall(Function *Callee, Module *Mod);
 }
 
 #endif