clang/test/SemaCXX/warn-large-by-value-copy.cpp

   1 // RUN: %clang_cc1 -verify -fsyntax-only -Wlarge-by-value-copy=100 %s
   2
   3 // rdar://8548050
   4 namespace rdar8548050 {
   5
   6 struct S100 {
   7     char x[100];
   8 };
   9
  10 struct S101 {
  11     char x[101];
  12 };
  13
  14 S100 f100(S100 s) { return s; }
  15
  16 S101 f101(S101 s) { return s; } // expected-warning {{return value of 'f101' is a large (101 bytes) pass-by-value object}} \
  17                                 // expected-warning {{'s' is a large (101 bytes) pass-by-value argument}}
  18
  19 void f101_no_param_name(S101) {} // expected-warning {{'' is a large (101 bytes) pass-by-value argument}}
  20
  21 // FIXME: Don't warn when when the return value is subject to (N)RVO.
  22
  23 template <typename T> T foo_template(T);
  24 template <> S101 foo_template(S101) { return S101(); } // expected-warning {{return value of 'foo_template<rdar8548050::S101>' is a large}}
  25                                                        // expected-warning@-1 {{'' is a large (101 bytes) pass-by-value argument}}
  26
  27 typedef int Arr[200];
  28 void farr(Arr a) { }
  29
  30 struct NonPOD {
  31   char x[200];
  32   virtual void m();
  33 };
  34
  35 NonPOD fNonPOD(NonPOD s) { return s; }
  36
  37 template <unsigned size>
  38 struct TS {
  39     char x[size];
  40 };
  41
  42 template <unsigned size>
  43 void tf(TS<size> ts) {} // expected-warning {{ts' is a large (300 bytes) pass-by-value argument}}
  44
  45 void g() {
  46     TS<300> ts;
  47     tf<300>(ts); // expected-note {{instantiation}}
  48 }
  49
  50 }
  51
  52 template<typename T> class DependentPOD {
  53   enum b { x };
  54   b foo() { return x; }
  55 };