llvm-project/clang/test/CodeGenCXX/catch-undef-behavior.cpp

89 lines
2.9 KiB
C++

// 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();
}
// CHECK: @_Z12lsh_overflow
int lsh_overflow(int a, int b) {
// CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31
// CHECK-NEXT: br i1 %[[INBOUNDS]]
// CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]]
// CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]]
// This is present for C++11 but not for C: C++ core issue 1457 allows a '1'
// to be shifted into the sign bit, but not out of it.
// CHECK-NEXT: %[[SHIFTED_OUT_NOT_SIGN:.*]] = lshr i32 %[[SHIFTED_OUT]], 1
// CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT_NOT_SIGN]], 0
// CHECK-NEXT: br i1 %[[NO_OVERFLOW]]
// CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]]
// CHECK-NEXT: ret i32 %[[RET]]
return a << b;
}