Rename asan-check-lifetime into asan-stack-use-after-scope

[vitalybuka]

Summary

This is done for consistency with asan-use-after-return.
I see no other users than tests.

[kcc]

LGTM, let me commit

lib/Transforms/Instrumentation/AddressSanitizer.cpp

static cl::opt<int> ClMaxInsnsToInstrumentPerBB(
     cl::desc("maximal number of instructions to instrument in any given BB"),
     cl::Hidden);
 // This flag may need to be replaced with -f[no]asan-stack.
 static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
                              cl::Hidden, cl::init(true));
 static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
                                       cl::desc("Check stack-use-after-return"),
                                       cl::Hidden, cl::init(true));
+static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
+                                     cl::desc("Check stack-use-after-scope"),
+                                     cl::Hidden, cl::init(false));
 // This flag may need to be replaced with -f[no]asan-globals.
 static cl::opt<bool> ClGlobals("asan-globals",
                                cl::desc("Handle global objects"), cl::Hidden,
                                cl::init(true));
 static cl::opt<bool> ClInitializers("asan-initialization-order",
                                     cl::desc("Handle C++ initializer order"),
                                     cl::Hidden, cl::init(true));
 static cl::opt<bool> ClInvalidPointerPairs(
static cl::opt<bool> ClOptSameTemp(
     cl::Hidden, cl::init(true));
 static cl::opt<bool> ClOptGlobals("asan-opt-globals",
                                   cl::desc("Don't instrument scalar globals"),
                                   cl::Hidden, cl::init(true));
 static cl::opt<bool> ClOptStack(
     "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
     cl::Hidden, cl::init(false));
 
-static cl::opt<bool> ClCheckLifetime(
-    "asan-check-lifetime",
-    cl::desc("Use llvm.lifetime intrinsics to insert extra checks"), cl::Hidden,
-    cl::init(false));
-
 static cl::opt<bool> ClDynamicAllocaStack(
     "asan-stack-dynamic-alloca",
     cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
     cl::init(true));
 
 static cl::opt<uint32_t> ClForceExperiment(
     "asan-force-experiment",
     cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
   }
 
   /// \brief Collect lifetime intrinsic calls to check for use-after-scope
   /// errors.
   void visitIntrinsicInst(IntrinsicInst &II) {
     Intrinsic::ID ID = II.getIntrinsicID();
     if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
     if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
-    if (!ClCheckLifetime) return;
+    if (!ClUseAfterScope) return;
     if (ID != Intrinsic::lifetime_start && ID != Intrinsic::lifetime_end)
       return;
     // Found lifetime intrinsic, add ASan instrumentation if necessary.
     ConstantInt *Size = dyn_cast<ConstantInt>(II.getArgOperand(0));
     // If size argument is undefined, don't do anything.
     if (Size->isMinusOne()) return;
     // Check that size doesn't saturate uint64_t and can
     // be stored in IntptrTy.

test/Instrumentation/AddressSanitizer/lifetime-uar.ll

 ; Test handling of llvm.lifetime intrinsics in UAR mode.
-; RUN: opt < %s -asan -asan-module -asan-use-after-return -asan-check-lifetime -S | FileCheck %s
+; RUN: opt < %s -asan -asan-module -asan-use-after-return -asan-use-after-scope -S | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 
 declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind
 declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind
 
 define i32 @basic_test() sanitize_address {
   ; CHECK-LABEL: define i32 @basic_test()

test/Instrumentation/AddressSanitizer/lifetime.ll

 ; Test hanlding of llvm.lifetime intrinsics.
-; RUN: opt < %s -asan -asan-module -asan-check-lifetime -asan-use-after-return=0 -S | FileCheck %s
+; RUN: opt < %s -asan -asan-module -asan-use-after-scope -asan-use-after-return=0 -S | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind
 declare void @llvm.lifetime.end(i64, i8* nocapture) nounwind
 
 define void @lifetime_no_size() sanitize_address {