test/CodeGenCXX/catch-undef-behavior.cpp

// RUN: %clang_cc1 -fcatch-undefined-behavior -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s

// CHECK: @_Z17reference_binding
void reference_binding(int *p) {
  // C++ core issue 453: If an lvalue to which a reference is directly bound
  // designates neither an existing object or function of an appropriate type,
  // nor a region of storage of suitable size and alignment to contain an object
  // of the reference's type, the behavior is undefined.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
  int &r = *p;
}

struct S {
  double d;
  int a, b;
  virtual int f();
};

// CHECK: @_Z13member_access
void member_access(S *p) {
  // (1) Check 'p' is appropriately sized and aligned for member access.

  // FIXME: Check vptr is for 'S' or a class derived from 'S'.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0

  // (2) Check 'p->b' is appropriately sized and aligned for a load.

  // FIXME: Suppress this in the trivial case of a member access, because we
  // know we've just checked the member access expression itself.

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
  int k = p->b;

  // (3) Check 'p' is appropriately sized and aligned for member function call.

  // FIXME: Check vptr is for 'S' or a class derived from 'S'.

  // CHECK: icmp ne {{.*}}, null

  // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64
  // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24

  // CHECK: %[[PTRINT:.*]] = ptrtoint
  // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7
  // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0
  k = p->f();
}