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// RUN: %clang_cc1 %s -triple x86_64-unknown-linux-gnu -emit-llvm -fextend-variable-liveness -fsanitize=null -fsanitize-trap=null -o - | FileCheck --check-prefixes=CHECK,NULL --implicit-check-not=ubsantrap %s
// RUN: %clang_cc1 %s -triple x86_64-unknown-linux-gnu -emit-llvm -fextend-variable-liveness -o - | FileCheck %s
// With -fextend-variable-liveness, the compiler previously generated a fake.use of any
// reference variable at the end of the scope in which its alloca exists. This
// caused two issues, where we would get fake uses for uninitialized variables
// if that variable was declared after an early-return, and UBSan's null checks
// would complain about this.
// This test verifies that UBSan does not produce null-checks for arguments to
// llvm.fake.use, and that fake uses are not emitted for a variable on paths
// it has not been declared.
struct A { short s1, s2; };
extern long& getA();
void foo()
{
auto& va = getA();
if (va < 5)
return;
auto& vb = getA();
}
// CHECK-LABEL: define{{.*}}foo
// CHECK: [[VA_CALL:%.+]] = call{{.*}} ptr @_Z4getAv()
/// We check here for the first UBSan check for "va".
// NULL: [[VA_ISNULL:%.+]] = icmp ne ptr [[VA_CALL]], null
// NULL: br i1 [[VA_ISNULL]], label %{{[^,]+}}, label %[[VA_TRAP:[^,]+]]
// NULL: [[VA_TRAP]]:
// NULL: call void @llvm.ubsantrap(
// CHECK: [[VA_PTR:%.+]] = load ptr, ptr %va
// CHECK-NEXT: [[VA_CMP:%.+]] = load i64, ptr [[VA_PTR]]
// CHECK-NEXT: [[VA_CMP_RES:%.+]] = icmp slt i64 [[VA_CMP]], 5
// CHECK-NEXT: br i1 [[VA_CMP_RES]], label %[[EARLY_EXIT:[^,]+]], label %[[NOT_EARLY_EXIT:[^,]+]]
// CHECK: [[EARLY_EXIT]]:
// CHECK: br label %cleanup
/// The fake use for "vb" only appears on the path where its declaration is
/// reached.
// CHECK: [[NOT_EARLY_EXIT]]:
// CHECK: [[VB_CALL:%.+]] = call{{.*}} ptr @_Z4getAv()
/// We check here for the second UBSan check for "vb".
// NULL: [[VB_ISNULL:%.+]] = icmp ne ptr [[VB_CALL]], null
// NULL: br i1 [[VB_ISNULL]], label %{{[^,]+}}, label %[[VB_TRAP:[^,]+]]
// NULL: [[VB_TRAP]]:
// NULL: call void @llvm.ubsantrap(
// CHECK: [[VB_FAKE_USE:%.+]] = load ptr, ptr %vb
// CHECK-NEXT: call void (...) @llvm.fake.use(ptr [[VB_FAKE_USE]])
// CHECK: br label %cleanup
// CHECK: cleanup:
// CHECK: [[VA_FAKE_USE:%.+]] = load ptr, ptr %va
// CHECK-NEXT: call void (...) @llvm.fake.use(ptr [[VA_FAKE_USE]])
// NULL: declare void @llvm.ubsantrap
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