clang/test/SemaCXX/warn-using-namespace-in-header.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -Wheader-hygiene -verify %s
   2
   3 #ifdef BE_THE_HEADER
   4 namespace warn_in_header_in_global_context {}
   5 using namespace warn_in_header_in_global_context; // expected-warning {{using namespace directive in global context in header}}
   6
   7 // While we want to error on the previous using directive, we don't when we are
   8 // inside a namespace
   9 namespace dont_warn_here {
  10 using namespace warn_in_header_in_global_context;
  11 }
  12
  13 // We should warn in toplevel extern contexts.
  14 namespace warn_inside_linkage {}
  15 extern "C++" {
  16 using namespace warn_inside_linkage; // expected-warning {{using namespace directive in global context in header}}
  17 }
  18
  19 // This is really silly, but we should warn on it:
  20 extern "C++" {
  21 extern "C" {
  22 extern "C++" {
  23 using namespace warn_inside_linkage; // expected-warning {{using namespace directive in global context in header}}
  24 }
  25 }
  26 }
  27
  28 // But we shouldn't warn in extern contexts inside namespaces.
  29 namespace dont_warn_here {
  30 extern "C++" {
  31 using namespace warn_in_header_in_global_context;
  32 }
  33 }
  34
  35 // We also shouldn't warn in case of functions.
  36 inline void foo() {
  37   using namespace warn_in_header_in_global_context;
  38 }
  39
  40
  41 namespace macronamespace {}
  42 #define USING_MACRO using namespace macronamespace;
  43
  44 // |using namespace| through a macro should warn if the instantiation is in a
  45 // header.
  46 USING_MACRO // expected-warning {{using namespace directive in global context in header}}
  47
  48 #else
  49
  50 #define BE_THE_HEADER
  51 #include __FILE__
  52
  53 namespace dont_warn {}
  54 using namespace dont_warn;
  55
  56 // |using namespace| through a macro shouldn't warn if the instantiation is in a
  57 // cc file.
  58 USING_MACRO
  59
  60 // Check behavior of line markers.
  61 namespace warn_header_with_line_marker {}
  62 # 1 "XXX.h" 1
  63 using namespace warn_header_with_line_marker; // expected-warning {{using namespace directive in global context in header}}
  64 # 70 "warn-using-namespace-in-header.cpp" 2
  65
  66 namespace nowarn_after_line_marker {}
  67 using namespace nowarn_after_line_marker;
  68
  69 #endif