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

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