Reimplement the parameter attributes support, phase #1. hilights:

1. There is now a "PAListPtr" class, which is a smart pointer around
   the underlying uniqued parameter attribute list object, and manages
   its refcount.  It is now impossible to mess up the refcount.
2. PAListPtr is now the main interface to the underlying object, and
   the underlying object is now completely opaque.
3. Implementation details like SmallVector and FoldingSet are now no
   longer part of the interface.
4. You can create a PAListPtr with an arbitrary sequence of
   ParamAttrsWithIndex's, no need to make a SmallVector of a specific 
   size (you can just use an array or scalar or vector if you wish).
5. All the client code that had to check for a null pointer before
   dereferencing the pointer is simplified to just access the 
   PAListPtr directly.
6. The interfaces for adding attrs to a list and removing them is a
   bit simpler.

Phase #2 will rename some stuff (e.g. PAListPtr) and do other less 
invasive changes.

llvm-svn: 48289

1 files changed, 16 insertions, 63 deletions

diff --git a/llvm/lib/VMCore/Instructions.cpp b/llvm/lib/VMCore/Instructions.cpp
index f7401ec9797..ee9a02e91ac 100644
--- a/llvm/lib/VMCore/Instructions.cpp
+++ b/llvm/lib/VMCore/Instructions.cpp
@@ -17,7 +17,6 @@
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
 #include "llvm/Instructions.h"
-#include "llvm/ParamAttrsList.h"
 #include "llvm/Support/CallSite.h"
 #include "llvm/Support/ConstantRange.h"
 #include "llvm/Support/MathExtras.h"
@@ -43,13 +42,13 @@ void CallSite::setCallingConv(unsigned CC) {
   else
     cast<InvokeInst>(I)->setCallingConv(CC);
 }
-const ParamAttrsList* CallSite::getParamAttrs() const {
+const PAListPtr &CallSite::getParamAttrs() const {
   if (CallInst *CI = dyn_cast<CallInst>(I))
     return CI->getParamAttrs();
   else
     return cast<InvokeInst>(I)->getParamAttrs();
 }
-void CallSite::setParamAttrs(const ParamAttrsList *PAL) {
+void CallSite::setParamAttrs(const PAListPtr &PAL) {
   if (CallInst *CI = dyn_cast<CallInst>(I))
     CI->setParamAttrs(PAL);
   else
@@ -243,12 +242,9 @@ Value *PHINode::hasConstantValue(bool AllowNonDominatingInstruction) const {
 
 CallInst::~CallInst() {
   delete [] OperandList;
-  if (ParamAttrs)
-    ParamAttrs->dropRef();
 }
 
 void CallInst::init(Value *Func, Value* const *Params, unsigned NumParams) {
-  ParamAttrs = 0;
   NumOperands = NumParams+1;
   Use *OL = OperandList = new Use[NumParams+1];
   OL[0].init(Func, this);
@@ -269,7 +265,6 @@ void CallInst::init(Value *Func, Value* const *Params, unsigned NumParams) {
 }
 
 void CallInst::init(Value *Func, Value *Actual1, Value *Actual2) {
-  ParamAttrs = 0;
   NumOperands = 3;
   Use *OL = OperandList = new Use[3];
   OL[0].init(Func, this);
@@ -292,7 +287,6 @@ void CallInst::init(Value *Func, Value *Actual1, Value *Actual2) {
 }
 
 void CallInst::init(Value *Func, Value *Actual) {
-  ParamAttrs = 0;
   NumOperands = 2;
   Use *OL = OperandList = new Use[2];
   OL[0].init(Func, this);
@@ -311,7 +305,6 @@ void CallInst::init(Value *Func, Value *Actual) {
 }
 
 void CallInst::init(Value *Func) {
-  ParamAttrs = 0;
   NumOperands = 1;
   Use *OL = OperandList = new Use[1];
   OL[0].init(Func, this);
@@ -360,8 +353,7 @@ CallInst::CallInst(Value *Func, const std::string &Name,
 
 CallInst::CallInst(const CallInst &CI)
   : Instruction(CI.getType(), Instruction::Call, new Use[CI.getNumOperands()],
-                CI.getNumOperands()),
-    ParamAttrs(0) {
+                CI.getNumOperands()) {
   setParamAttrs(CI.getParamAttrs());
   SubclassData = CI.SubclassData;
   Use *OL = OperandList;
@@ -370,21 +362,8 @@ CallInst::CallInst(const CallInst &CI)
     OL[i].init(InOL[i], this);
 }
 
-void CallInst::setParamAttrs(const ParamAttrsList *newAttrs) {
-  if (ParamAttrs == newAttrs)
-    return;
-
-  if (ParamAttrs)
-    ParamAttrs->dropRef();
-
-  if (newAttrs)
-    newAttrs->addRef();
-
-  ParamAttrs = newAttrs; 
-}
-
 bool CallInst::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
-  if (ParamAttrs && ParamAttrs->paramHasAttr(i, attr))
+  if (ParamAttrs.paramHasAttr(i, attr))
     return true;
   if (const Function *F = getCalledFunction())
     return F->paramHasAttr(i, attr);
@@ -392,11 +371,7 @@ bool CallInst::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
 }
 
 uint16_t CallInst::getParamAlignment(uint16_t i) const {
-  if (ParamAttrs && ParamAttrs->getParamAlignment(i))
-    return ParamAttrs->getParamAlignment(i);
-  if (const Function *F = getCalledFunction())
-    return F->getParamAlignment(i);
-  return 0;
+  return ParamAttrs.getParamAlignment(i);
 }
 
 /// @brief Determine if the call does not access memory.
@@ -428,21 +403,20 @@ bool CallInst::hasStructRetAttr() const {
 
 /// @brief Determine if any call argument is an aggregate passed by value.
 bool CallInst::hasByValArgument() const {
-  if (ParamAttrs && ParamAttrs->hasAttrSomewhere(ParamAttr::ByVal))
+  if (ParamAttrs.hasAttrSomewhere(ParamAttr::ByVal))
     return true;
   // Be consistent with other methods and check the callee too.
   if (const Function *F = getCalledFunction())
-    if (const ParamAttrsList *PAL = F->getParamAttrs())
-      return PAL->hasAttrSomewhere(ParamAttr::ByVal);
+    return F->getParamAttrs().hasAttrSomewhere(ParamAttr::ByVal);
   return false;
 }
 
 void CallInst::setDoesNotThrow(bool doesNotThrow) {
-  const ParamAttrsList *PAL = getParamAttrs();
+  PAListPtr PAL = getParamAttrs();
   if (doesNotThrow)
-    PAL = ParamAttrsList::includeAttrs(PAL, 0, ParamAttr::NoUnwind);
+    PAL = PAL.addAttr(0, ParamAttr::NoUnwind);
   else
-    PAL = ParamAttrsList::excludeAttrs(PAL, 0, ParamAttr::NoUnwind);
+    PAL = PAL.removeAttr(0, ParamAttr::NoUnwind);
   setParamAttrs(PAL);
 }
 
@@ -453,13 +427,10 @@ void CallInst::setDoesNotThrow(bool doesNotThrow) {
 
 InvokeInst::~InvokeInst() {
   delete [] OperandList;
-  if (ParamAttrs)
-    ParamAttrs->dropRef();
 }
 
 void InvokeInst::init(Value *Fn, BasicBlock *IfNormal, BasicBlock *IfException,
                       Value* const *Args, unsigned NumArgs) {
-  ParamAttrs = 0;
   NumOperands = 3+NumArgs;
   Use *OL = OperandList = new Use[3+NumArgs];
   OL[0].init(Fn, this);
@@ -484,8 +455,7 @@ void InvokeInst::init(Value *Fn, BasicBlock *IfNormal, BasicBlock *IfException,
 
 InvokeInst::InvokeInst(const InvokeInst &II)
   : TerminatorInst(II.getType(), Instruction::Invoke,
-                   new Use[II.getNumOperands()], II.getNumOperands()),
-    ParamAttrs(0) {
+                   new Use[II.getNumOperands()], II.getNumOperands()) {
   setParamAttrs(II.getParamAttrs());
   SubclassData = II.SubclassData;
   Use *OL = OperandList, *InOL = II.OperandList;
@@ -503,21 +473,8 @@ void InvokeInst::setSuccessorV(unsigned idx, BasicBlock *B) {
   return setSuccessor(idx, B);
 }
 
-void InvokeInst::setParamAttrs(const ParamAttrsList *newAttrs) {
-  if (ParamAttrs == newAttrs)
-    return;
-
-  if (ParamAttrs)
-    ParamAttrs->dropRef();
-
-  if (newAttrs)
-    newAttrs->addRef();
-
-  ParamAttrs = newAttrs; 
-}
-
 bool InvokeInst::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
-  if (ParamAttrs && ParamAttrs->paramHasAttr(i, attr))
+  if (ParamAttrs.paramHasAttr(i, attr))
     return true;
   if (const Function *F = getCalledFunction())
     return F->paramHasAttr(i, attr);
@@ -525,11 +482,7 @@ bool InvokeInst::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
 }
 
 uint16_t InvokeInst::getParamAlignment(uint16_t i) const {
-  if (ParamAttrs && ParamAttrs->getParamAlignment(i))
-    return ParamAttrs->getParamAlignment(i);
-  if (const Function *F = getCalledFunction())
-    return F->getParamAlignment(i);
-  return 0;
+  return ParamAttrs.getParamAlignment(i);
 }
 
 /// @brief Determine if the call does not access memory.
@@ -553,11 +506,11 @@ bool InvokeInst::doesNotThrow() const {
 }
 
 void InvokeInst::setDoesNotThrow(bool doesNotThrow) {
-  const ParamAttrsList *PAL = getParamAttrs();
+  PAListPtr PAL = getParamAttrs();
   if (doesNotThrow)
-    PAL = ParamAttrsList::includeAttrs(PAL, 0, ParamAttr::NoUnwind);
+    PAL = PAL.addAttr(0, ParamAttr::NoUnwind);
   else
-    PAL = ParamAttrsList::excludeAttrs(PAL, 0, ParamAttr::NoUnwind);
+    PAL = PAL.removeAttr(0, ParamAttr::NoUnwind);
   setParamAttrs(PAL);
 }