[IR] Remove size argument from lifetime intrinsics (#150248)

Now that #149310 has restricted lifetime intrinsics to only work on
allocas, we can also drop the explicit size argument. Instead, the size
is implied by the alloca.

This removes the ability to only mark a prefix of an alloca alive/dead.
We never used that capability, so we should remove the need to handle
that possibility everywhere (though many key places, including stack
coloring, did not actually respect this).

1 files changed, 3 insertions, 7 deletions

diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index cad6731..e2f11b86 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -300,16 +300,12 @@ void AggExprEmitter::withReturnValueSlot(
   Address RetAddr = Address::invalid();
 
   EHScopeStack::stable_iterator LifetimeEndBlock;
-  llvm::Value *LifetimeSizePtr = nullptr;
   llvm::IntrinsicInst *LifetimeStartInst = nullptr;
   if (!UseTemp) {
     RetAddr = Dest.getAddress();
   } else {
     RetAddr = CGF.CreateMemTempWithoutCast(RetTy, "tmp");
-    llvm::TypeSize Size =
-        CGF.CGM.getDataLayout().getTypeAllocSize(CGF.ConvertTypeForMem(RetTy));
-    LifetimeSizePtr = CGF.EmitLifetimeStart(Size, RetAddr.getBasePointer());
-    if (LifetimeSizePtr) {
+    if (CGF.EmitLifetimeStart(RetAddr.getBasePointer())) {
       LifetimeStartInst =
           cast<llvm::IntrinsicInst>(std::prev(Builder.GetInsertPoint()));
       assert(LifetimeStartInst->getIntrinsicID() ==
@@ -317,7 +313,7 @@ void AggExprEmitter::withReturnValueSlot(
              "Last insertion wasn't a lifetime.start?");
 
       CGF.pushFullExprCleanup<CodeGenFunction::CallLifetimeEnd>(
-          NormalEHLifetimeMarker, RetAddr, LifetimeSizePtr);
+          NormalEHLifetimeMarker, RetAddr);
       LifetimeEndBlock = CGF.EHStack.stable_begin();
     }
   }
@@ -338,7 +334,7 @@ void AggExprEmitter::withReturnValueSlot(
     // Since we're not guaranteed to be in an ExprWithCleanups, clean up
     // eagerly.
     CGF.DeactivateCleanupBlock(LifetimeEndBlock, LifetimeStartInst);
-    CGF.EmitLifetimeEnd(LifetimeSizePtr, RetAddr.getBasePointer());
+    CGF.EmitLifetimeEnd(RetAddr.getBasePointer());
   }
 }