From 81d1a2207d96163a81afc6a7ad11cba41ea72dff Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 10 Feb 2004 17:41:01 +0000
Subject: [PATCH] initialization calls now return argc.  If the program uses
 the argc value passed into main, make sure they use the return value of the
 init call instead of the one passed in.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11262 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../Instrumentation/BlockProfiling.cpp        | 57 +++++++++++--------
 1 file changed, 32 insertions(+), 25 deletions(-)

diff --git a/lib/Transforms/Instrumentation/BlockProfiling.cpp b/lib/Transforms/Instrumentation/BlockProfiling.cpp
index 7b38d70d9e3..8dacc92bc26 100644
--- a/lib/Transforms/Instrumentation/BlockProfiling.cpp
+++ b/lib/Transforms/Instrumentation/BlockProfiling.cpp
@@ -31,7 +31,7 @@ static void insertInitializationCall(Function *MainFn, const char *FnName,
   const Type *ArgVTy = PointerType::get(PointerType::get(Type::SByteTy));
   const Type *UIntPtr = PointerType::get(Type::UIntTy);
   Module &M = *MainFn->getParent();
-  Function *InitFn = M.getOrInsertFunction(FnName, Type::VoidTy, Type::IntTy,
+  Function *InitFn = M.getOrInsertFunction(FnName, Type::IntTy, Type::IntTy,
                                            ArgVTy, UIntPtr, Type::UIntTy, 0);
 
   // This could force argc and argv into programs that wouldn't otherwise have
@@ -45,29 +45,6 @@ static void insertInitializationCall(Function *MainFn, const char *FnName,
   BasicBlock::iterator InsertPos = Entry->begin();
   while (isa<AllocaInst>(InsertPos)) ++InsertPos;
 
-  Function::aiterator AI;
-  switch (MainFn->asize()) {
-  default:
-  case 2:
-    AI = MainFn->abegin(); ++AI;
-    if (AI->getType() != ArgVTy) {
-      Args[1] = new CastInst(AI, ArgVTy, "argv.cast", InsertPos);
-    } else {
-      Args[1] = AI;
-    }
-
-  case 1:
-    AI = MainFn->abegin();
-    if (AI->getType() != Type::IntTy) {
-      Args[0] = new CastInst(AI, Type::IntTy, "argc.cast", InsertPos);
-    } else {
-      Args[0] = AI;
-    }
-    
-  case 0:
-    break;
-  }
-
   ConstantPointerRef *ArrayCPR = ConstantPointerRef::get(Array);
   std::vector<Constant*> GEPIndices(2, Constant::getNullValue(Type::LongTy));
   Args[2] = ConstantExpr::getGetElementPtr(ArrayCPR, GEPIndices);
@@ -76,7 +53,37 @@ static void insertInitializationCall(Function *MainFn, const char *FnName,
     cast<ArrayType>(Array->getType()->getElementType())->getNumElements();
   Args[3] = ConstantUInt::get(Type::UIntTy, NumElements);
   
-  new CallInst(InitFn, Args, "", InsertPos);
+  Instruction *InitCall = new CallInst(InitFn, Args, "newargc", InsertPos);
+
+  // If argc or argv are not available in main, just pass null values in.
+  Function::aiterator AI;
+  switch (MainFn->asize()) {
+  default:
+  case 2:
+    AI = MainFn->abegin(); ++AI;
+    if (AI->getType() != ArgVTy) {
+      InitCall->setOperand(2, new CastInst(AI, ArgVTy, "argv.cast", InitCall));
+    } else {
+      InitCall->setOperand(2, AI);
+    }
+
+  case 1:
+    AI = MainFn->abegin();
+    // If the program looked at argc, have it look at the return value of the
+    // init call instead.
+    if (AI->getType() != Type::IntTy) {
+      if (!AI->use_empty())
+        AI->replaceAllUsesWith(new CastInst(InitCall, AI->getType(), "",
+                                            InsertPos));
+      InitCall->setOperand(1, new CastInst(AI, Type::IntTy, "argc.cast",
+                                           InitCall));
+    } else {
+      AI->replaceAllUsesWith(InitCall);
+      InitCall->setOperand(1, AI);
+    }
+    
+  case 0: break;
+  }
 }
 
 static void IncrementCounterInBlock(BasicBlock *BB, unsigned CounterNum,