GenerateExportHeader: use C++11 attributes if available

The minimum compiler versions were determined in the GCC and LLVM
repositories as follows. The first release containing a commit is the
lowest release tag listed by ``git tag --contains <commit>``. Since a
point release of an older series can be listed although it lacks the
commit, ``git grep`` at the tag confirms the change.

1. The header requires __has_cpp_attribute to accept scoped names such
   as gnu::visibility.  The commit adding this is the oldest one whose
   diff touches a line parsing the "::" token:

     gcc$ git log --reverse --format=%H -G'CPP_SCOPE' \
            -- gcc/c-family/c-lex.c
     llvm-project$ git log --reverse --format=%H \
            -G'Ident__has_cpp_attribute.*coloncolon' -- clang/lib/Lex

   This yields 42fd12b1e7fc50183bcf62861aae81301a9efbcf in
   releases/gcc-5.1.0 and a0344c5d7b9b748a2244dce393ceb55e83b495d6 in
   llvmorg-3.6.0.

2. The GCC commit accepting mixed attribute spellings references its bug
   https://gcc.gnu.org/PR69585 in the message:

     gcc$ git log --format=%H --grep=c++/69585

   This yields aec868578d8515763d75693c1fdfbc30ff0a1e68 in
   releases/gcc-13.1.0.

Fixes: #22908
Issue: #20527

Help/release/dev/GenerateExportHeader-cxx-attributes.rst

@@ -0,0 +1,8 @@
+GenerateExportHeader-cxx-attributes
+-----------------------------------
+
+* The :module:`GenerateExportHeader` module's
+  :command:`generate_export_header` command gained a ``CXX_ATTRIBUTES``
+  option to define the export, no-export and deprecation macros as C++11
+  attributes, which, unlike the compiler-specific spellings, can be combined
+  with other C++11 attributes.

Modules/GenerateExportHeader.cmake

@@ -68,6 +68,7 @@ Generating Export Header
       [PREFIX_NAME <prefix>]
       [CUSTOM_CONTENT_FROM_VARIABLE <variable>]
       [INCLUDE_GUARD_NAME <include-guard-name>]
+      [CXX_ATTRIBUTES]
     )
 
   By default, this command generates a header file named
@@ -190,6 +191,46 @@ Generating Export Header
       // ...
       #endif /* <include-guard-name> */
 
+  ``CXX_ATTRIBUTES``
+    .. versionadded:: 4.6
+
+    If specified, the export, no-export and deprecation macros expand to
+    C++11 attributes, such as ``[[gnu::visibility("default")]]``,
+    ``[[gnu::dllexport]]`` and ``[[gnu::deprecated]]``, which can be
+    combined with other C++11 attributes.  The generated header falls back
+    to the compiler-specific spellings, such as ``__attribute__`` and
+    ``__declspec``, if the consumer compiles C, compiles C++ older than
+    C++11, does not support the attribute, or is Qt's ``moc``.  The
+    fallback is decided by the preprocessor, so the header remains usable
+    by consumers using a different compiler.  The C++11 attributes are used
+    with GCC 5 and Clang 3.6 or newer.  This matters for GCC versions before
+    13, which reject the compiler-specific spellings combined with C++11
+    attributes, such as ``struct EXAMPLE_EXPORT [[nodiscard]] Struct``.
+
+    A C++11 attribute that follows a type applies to the type, not to the
+    declared symbol.  The macros must therefore be placed at the start of a
+    declaration or right after the class key.  Otherwise, compilers either
+    reject the declaration or ignore the attribute and do not export the
+    symbol:
+
+    .. code-block:: c++
+
+      class EXAMPLE_EXPORT Class
+      {
+      public:
+        EXAMPLE_NO_EXPORT int method_excluded() const;
+        EXAMPLE_EXPORT static int const data_exported;
+      };
+
+      EXAMPLE_EXPORT int function_exported();
+      EXAMPLE_DEPRECATED_EXPORT int function_deprecated();
+      EXAMPLE_EXPORT extern int const data_exported;
+
+      int EXAMPLE_EXPORT function_not_exported(); // wrong placement
+
+    The compiler-specific spellings accept the same placement, so the
+    declarations compile with either.
+
 Deprecated Command
 """"""""""""""""""
 
@@ -564,6 +605,10 @@ macro(_DO_SET_MACRO_VALUES TARGET_LIBRARY)
   set(DEFINE_EXPORT)
   set(DEFINE_IMPORT)
   set(DEFINE_NO_EXPORT)
+  set(CXX_ATTRIBUTE_DEPRECATED "gnu::deprecated")
+  set(CXX_ATTRIBUTE_EXPORT)
+  set(CXX_ATTRIBUTE_IMPORT)
+  set(CXX_ATTRIBUTE_NO_EXPORT)
 
   if (COMPILER_HAS_DEPRECATED_ATTR AND NOT WIN32)
     set(DEFINE_DEPRECATED "__attribute__ ((__deprecated__))")
@@ -577,17 +622,47 @@ macro(_DO_SET_MACRO_VALUES TARGET_LIBRARY)
     if(WIN32 OR CYGWIN)
       set(DEFINE_EXPORT "__declspec(dllexport)")
       set(DEFINE_IMPORT "__declspec(dllimport)")
+      set(CXX_ATTRIBUTE_EXPORT "gnu::dllexport")
+      set(CXX_ATTRIBUTE_IMPORT "gnu::dllimport")
     elseif(COMPILER_HAS_HIDDEN_VISIBILITY)
       set(DEFINE_EXPORT "__attribute__((visibility(\"default\")))")
       set(DEFINE_IMPORT "__attribute__((visibility(\"default\")))")
       set(DEFINE_NO_EXPORT "__attribute__((visibility(\"hidden\")))")
+      set(CXX_ATTRIBUTE_EXPORT "gnu::visibility(\"default\")")
+      set(CXX_ATTRIBUTE_IMPORT "gnu::visibility(\"default\")")
+      set(CXX_ATTRIBUTE_NO_EXPORT "gnu::visibility(\"hidden\")")
     endif()
   endif()
 endmacro()
 
+# Sets <out> to the preprocessor lines indented by <indent> that define the
+# macro <name> as <value>.  Given a C++11 <attribute>, the lines prefer
+# [[<attribute>]] in consumers that support it and fall back to <value>
+# otherwise.  Qt's moc always sees <value> because older versions of moc skip
+# classes declared with C++11 attributes.
+function(_generate_export_header_definition out indent name value attribute)
+  if(NOT attribute)
+    set(${out} "#${indent}define ${name} ${value}" PARENT_SCOPE)
+    return()
+  endif()
+
+  string(REGEX REPLACE "\\(.*" "" token "${attribute}")
+  string(JOIN "\n" definition
+    "#${indent}if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)"
+    "#${indent}  if __has_cpp_attribute(${token})"
+    "#${indent}    define ${name} [[${attribute}]]"
+    "#${indent}  endif"
+    "#${indent}endif"
+    "#${indent}ifndef ${name}"
+    "#${indent}  define ${name} ${value}"
+    "#${indent}endif"
+  )
+  set(${out} "${definition}" PARENT_SCOPE)
+endfunction()
+
 function(_DO_GENERATE_EXPORT_HEADER TARGET_LIBRARY)
   # Option overrides
-  set(options DEFINE_NO_DEPRECATED)
+  set(options DEFINE_NO_DEPRECATED CXX_ATTRIBUTES)
   set(oneValueArgs PREFIX_NAME BASE_NAME EXPORT_MACRO_NAME EXPORT_FILE_NAME
     DEPRECATED_MACRO_NAME NO_EXPORT_MACRO_NAME STATIC_DEFINE
     NO_DEPRECATED_MACRO_NAME CUSTOM_CONTENT_FROM_VARIABLE INCLUDE_GUARD_NAME)
@@ -675,6 +750,27 @@ function(_DO_GENERATE_EXPORT_HEADER TARGET_LIBRARY)
     endif()
   endif()
 
+  if(NOT _GEH_CXX_ATTRIBUTES)
+    set(CXX_ATTRIBUTE_DEPRECATED)
+    set(CXX_ATTRIBUTE_EXPORT)
+    set(CXX_ATTRIBUTE_IMPORT)
+    set(CXX_ATTRIBUTE_NO_EXPORT)
+  endif()
+
+  _generate_export_header_definition(EXPORT_DEFINITION "      "
+    "${EXPORT_MACRO_NAME}" "${DEFINE_EXPORT}" "${CXX_ATTRIBUTE_EXPORT}")
+  _generate_export_header_definition(IMPORT_DEFINITION "      "
+    "${EXPORT_MACRO_NAME}" "${DEFINE_IMPORT}" "${CXX_ATTRIBUTE_IMPORT}")
+  _generate_export_header_definition(NO_EXPORT_DEFINITION "    "
+    "${NO_EXPORT_MACRO_NAME}" "${DEFINE_NO_EXPORT}"
+    "${CXX_ATTRIBUTE_NO_EXPORT}")
+  # The GNU spelling of deprecation shares the availability of the export
+  # attributes, so that the combined macros never mix C++11 attributes with
+  # the legacy spellings, which Clang rejects after __declspec.
+  _generate_export_header_definition(DEPRECATED_DEFINITION "  "
+    "${DEPRECATED_MACRO_NAME}" "${DEFINE_DEPRECATED}"
+    "${CXX_ATTRIBUTE_DEPRECATED}")
+
   configure_file("${CMAKE_CURRENT_FUNCTION_LIST_DIR}/exportheader.cmake.in"
     "${EXPORT_FILE_NAME}" @ONLY)
 endfunction()

Modules/exportheader.cmake.in

@@ -9,20 +9,20 @@
 #  ifndef @EXPORT_MACRO_NAME@
 #    ifdef @EXPORT_IMPORT_CONDITION@
         /* We are building this library */
-#      define @EXPORT_MACRO_NAME@ @DEFINE_EXPORT@
+@EXPORT_DEFINITION@
 #    else
         /* We are using this library */
-#      define @EXPORT_MACRO_NAME@ @DEFINE_IMPORT@
+@IMPORT_DEFINITION@
 #    endif
 #  endif
 
 #  ifndef @NO_EXPORT_MACRO_NAME@
-#    define @NO_EXPORT_MACRO_NAME@ @DEFINE_NO_EXPORT@
+@NO_EXPORT_DEFINITION@
 #  endif
 #endif
 
 #ifndef @DEPRECATED_MACRO_NAME@
-#  define @DEPRECATED_MACRO_NAME@ @DEFINE_DEPRECATED@
+@DEPRECATED_DEFINITION@
 #endif
 
 #ifndef @DEPRECATED_MACRO_NAME@_EXPORT

Tests/QtAutogen/Complex/Bdir/CMakeLists.txt

@@ -4,6 +4,6 @@ set(CMAKE_AUTOMOC ON)
 set(CMAKE_INCLUDE_CURRENT_DIR_IN_INTERFACE ON)
 
 add_library(libB SHARED libB.cpp)
-generate_export_header(libB)
+generate_export_header(libB CXX_ATTRIBUTES)
 
 target_link_libraries(libB LINK_PUBLIC libA)

Tests/RunCMake/GenerateExportHeader/GEH.cmake

@@ -76,6 +76,7 @@ endmacro()
 
 macro_add_test_library(libshared)
 macro_add_test_library(libstatic)
+macro_add_test_library(libattributes)
 
 add_subdirectory(nodeprecated)
 add_subdirectory(includeguard)

Tests/RunCMake/GenerateExportHeader/exportheader_test.cpp

@@ -5,6 +5,7 @@
 
 #include <stdlib.h>
 
+#include "libattributes.h"
 #include "libshared.h"
 #include "libstatic.h"
 
@@ -164,11 +165,46 @@ int main()
   use_int(libstatic::data_exported);
   use_int(libstatic::data_excluded);
 
+  {
+    libattributes::Class l;
+    // l.method(); LINK ERROR
+    l.method_exported();
+    l.method_deprecated_exported();
+    // l.method_excluded(); LINK ERROR
+
+    // use_int(l.data); LINK ERROR
+    use_int(l.data_exported);
+    // use_int(l.data_excluded); LINK ERROR
+  }
+
+  {
+    libattributes::ExportedClass l;
+    l.method();
+#if defined(_WIN32) || defined(__CYGWIN__)
+    l.method_excluded();
+#else
+// l.method_excluded(); LINK ERROR (NOT WIN32 AND NOT CYGWIN)
+#endif
+  }
+
+  // libattributes::function(); LINK ERROR
+  libattributes::function_exported();
+  libattributes::function_deprecated_exported();
+  // libattributes::function_excluded(); LINK ERROR
+
+  // use_int(libattributes::data); LINK ERROR
+  use_int(libattributes::data_exported);
+  // use_int(libattributes::data_excluded); LINK ERROR
+
+  libattributes_function_c();
+
 #if defined(SRC_DIR) && defined(BIN_DIR)
   compare(SRC_DIR "/libshared_export.h",
           BIN_DIR "/libshared/libshared_export.h");
   compare(SRC_DIR "/libstatic_export.h",
           BIN_DIR "/libstatic/libstatic_export.h");
+  compare(SRC_DIR "/libattributes_export.h",
+          BIN_DIR "/libattributes/libattributes_export.h");
 #endif
 
   return 0;

Tests/RunCMake/GenerateExportHeader/libattributes/CMakeLists.txt

@@ -0,0 +1,37 @@
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+include(GenerateExportHeader)
+
+# Show that the export header defined with C++11 attributes exports and hides
+# symbols declared with the macros in leading position.
+
+add_library(libattributes SHARED libattributes.cpp)
+
+generate_export_header(libattributes CXX_ATTRIBUTES)
+
+# Show that consumers in language modes without C++11 attributes fall back to
+# the compiler-specific spelling.  Generators such as FASTBuild compile the
+# output of the Clang preprocessor, whose line markers are a GNU extension.
+set(no_line_marker_errors
+  $<$<COMPILE_LANG_AND_ID:C,Clang,AppleClang>:-Wno-gnu-line-marker>
+  $<$<COMPILE_LANG_AND_ID:CXX,Clang,AppleClang>:-Wno-gnu-line-marker>
+)
+
+if(CMAKE_C_COMPILER_ID MATCHES "^(GNU|Clang|AppleClang)$")
+  add_executable(libattributes_c main.c)
+  set_property(TARGET libattributes_c PROPERTY C_STANDARD 99)
+  target_compile_options(libattributes_c PRIVATE
+    -pedantic-errors ${no_line_marker_errors})
+  target_link_libraries(libattributes_c PRIVATE libattributes)
+endif()
+
+if(CMAKE_CXX_COMPILER_ID MATCHES "^(GNU|Clang|AppleClang)$")
+  add_executable(libattributes_cxx98 main.cpp)
+  set_target_properties(libattributes_cxx98 PROPERTIES
+    CXX_STANDARD 98
+    CXX_EXTENSIONS OFF
+  )
+  target_compile_options(libattributes_cxx98 PRIVATE
+    -pedantic-errors ${no_line_marker_errors})
+  target_link_libraries(libattributes_cxx98 PRIVATE libattributes)
+endif()

Tests/RunCMake/GenerateExportHeader/libattributes/libattributes.cpp

@@ -0,0 +1,68 @@
+#include "libattributes.h"
+
+int libattributes::Class::method() const
+{
+  return 0;
+}
+
+int libattributes::Class::method_exported() const
+{
+  return 0;
+}
+
+int libattributes::Class::method_deprecated_exported() const
+{
+  return 0;
+}
+
+int libattributes::Class::method_excluded() const
+{
+  return 0;
+}
+
+int const libattributes::Class::data = 1;
+
+int const libattributes::Class::data_exported = 1;
+
+int const libattributes::Class::data_excluded = 1;
+
+int libattributes::ExportedClass::method() const
+{
+  return 0;
+}
+
+int libattributes::ExportedClass::method_excluded() const
+{
+  return 0;
+}
+
+int libattributes::function()
+{
+  return 0;
+}
+
+int libattributes::function_exported()
+{
+  return 0;
+}
+
+int libattributes::function_deprecated_exported()
+{
+  return 0;
+}
+
+int libattributes::function_excluded()
+{
+  return 0;
+}
+
+int const libattributes::data = 1;
+
+int const libattributes::data_exported = 1;
+
+int const libattributes::data_excluded = 1;
+
+int libattributes_function_c(void)
+{
+  return 0;
+}

Tests/RunCMake/GenerateExportHeader/libattributes/libattributes.h

@@ -0,0 +1,51 @@
+#ifndef LIBATTRIBUTES_H
+#define LIBATTRIBUTES_H
+
+#include "libattributes_c.h"
+#include "libattributes_export.h"
+
+namespace libattributes {
+
+class Class
+{
+public:
+  int method() const;
+
+  LIBATTRIBUTES_EXPORT int method_exported() const;
+
+  LIBATTRIBUTES_DEPRECATED_EXPORT int method_deprecated_exported() const;
+
+  LIBATTRIBUTES_NO_EXPORT int method_excluded() const;
+
+  static int const data;
+
+  LIBATTRIBUTES_EXPORT static int const data_exported;
+
+  LIBATTRIBUTES_NO_EXPORT static int const data_excluded;
+};
+
+class LIBATTRIBUTES_EXPORT ExportedClass
+{
+public:
+  int method() const;
+
+  LIBATTRIBUTES_NO_EXPORT int method_excluded() const;
+};
+
+int function();
+
+LIBATTRIBUTES_EXPORT int function_exported();
+
+LIBATTRIBUTES_DEPRECATED_EXPORT int function_deprecated_exported();
+
+LIBATTRIBUTES_NO_EXPORT int function_excluded();
+
+extern int const data;
+
+LIBATTRIBUTES_EXPORT extern int const data_exported;
+
+LIBATTRIBUTES_NO_EXPORT extern int const data_excluded;
+
+} // namespace libattributes
+
+#endif

Tests/RunCMake/GenerateExportHeader/libattributes/libattributes_c.h

@@ -0,0 +1,16 @@
+#ifndef LIBATTRIBUTES_C_H
+#define LIBATTRIBUTES_C_H
+
+#include "libattributes_export.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+LIBATTRIBUTES_EXPORT int libattributes_function_c(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

Tests/RunCMake/GenerateExportHeader/libattributes/main.c

@@ -0,0 +1,6 @@
+#include "libattributes_c.h"
+
+int main(void)
+{
+  return libattributes_function_c();
+}

Tests/RunCMake/GenerateExportHeader/libattributes/main.cpp

@@ -0,0 +1,8 @@
+#include "libattributes.h"
+
+int main()
+{
+  libattributes::Class l;
+  return l.method_exported() + libattributes::function_exported() +
+    libattributes::data_exported - 1;
+}

Tests/RunCMake/GenerateExportHeader/reference/Cygwin/libattributes_export.h

@@ -0,0 +1,64 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllexport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllexport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllexport)
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllimport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllimport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllimport)
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __attribute__ ((__deprecated__))
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/Empty/libattributes_export.h

@@ -0,0 +1,50 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      define LIBATTRIBUTES_EXPORT
+#    else
+        /* We are using this library */
+#      define LIBATTRIBUTES_EXPORT
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/MinGW/libattributes_export.h

@@ -0,0 +1,64 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllexport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllexport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllexport)
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllimport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllimport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllimport)
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __declspec(deprecated)
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/UNIX/libattributes_export.h

@@ -0,0 +1,71 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::visibility)
+#          define LIBATTRIBUTES_EXPORT [[gnu::visibility("default")]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __attribute__((visibility("default")))
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::visibility)
+#          define LIBATTRIBUTES_EXPORT [[gnu::visibility("default")]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __attribute__((visibility("default")))
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#      if __has_cpp_attribute(gnu::visibility)
+#        define LIBATTRIBUTES_NO_EXPORT [[gnu::visibility("hidden")]]
+#      endif
+#    endif
+#    ifndef LIBATTRIBUTES_NO_EXPORT
+#      define LIBATTRIBUTES_NO_EXPORT __attribute__((visibility("hidden")))
+#    endif
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __attribute__ ((__deprecated__))
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/UNIX_DeprecatedOnly/libattributes_export.h

@@ -0,0 +1,50 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      define LIBATTRIBUTES_EXPORT
+#    else
+        /* We are using this library */
+#      define LIBATTRIBUTES_EXPORT
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __attribute__ ((__deprecated__))
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/Win32-Clang/libattributes_export.h

@@ -0,0 +1,64 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllexport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllexport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllexport)
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllimport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllimport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllimport)
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __declspec(deprecated)
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/Win32/libattributes_export.h

@@ -0,0 +1,64 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllexport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllexport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllexport)
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllimport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllimport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllimport)
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED __declspec(deprecated)
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */

Tests/RunCMake/GenerateExportHeader/reference/WinEmpty/libattributes_export.h

@@ -0,0 +1,64 @@
+
+#ifndef LIBATTRIBUTES_EXPORT_H
+#define LIBATTRIBUTES_EXPORT_H
+
+#ifdef LIBATTRIBUTES_STATIC_DEFINE
+#  define LIBATTRIBUTES_EXPORT
+#  define LIBATTRIBUTES_NO_EXPORT
+#else
+#  ifndef LIBATTRIBUTES_EXPORT
+#    ifdef libattributes_EXPORTS
+        /* We are building this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllexport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllexport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllexport)
+#      endif
+#    else
+        /* We are using this library */
+#      if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#        if __has_cpp_attribute(gnu::dllimport)
+#          define LIBATTRIBUTES_EXPORT [[gnu::dllimport]]
+#        endif
+#      endif
+#      ifndef LIBATTRIBUTES_EXPORT
+#        define LIBATTRIBUTES_EXPORT __declspec(dllimport)
+#      endif
+#    endif
+#  endif
+
+#  ifndef LIBATTRIBUTES_NO_EXPORT
+#    define LIBATTRIBUTES_NO_EXPORT
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED
+#  if defined(__cplusplus) && __cplusplus >= 201103L && defined(__has_cpp_attribute) && !defined(Q_MOC_RUN)
+#    if __has_cpp_attribute(gnu::deprecated)
+#      define LIBATTRIBUTES_DEPRECATED [[gnu::deprecated]]
+#    endif
+#  endif
+#  ifndef LIBATTRIBUTES_DEPRECATED
+#    define LIBATTRIBUTES_DEPRECATED
+#  endif
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_EXPORT LIBATTRIBUTES_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+#ifndef LIBATTRIBUTES_DEPRECATED_NO_EXPORT
+#  define LIBATTRIBUTES_DEPRECATED_NO_EXPORT LIBATTRIBUTES_NO_EXPORT LIBATTRIBUTES_DEPRECATED
+#endif
+
+/* NOLINTNEXTLINE(readability-avoid-unconditional-preprocessor-if) */
+#if 0 /* DEFINE_NO_DEPRECATED */
+#  ifndef LIBATTRIBUTES_NO_DEPRECATED
+#    define LIBATTRIBUTES_NO_DEPRECATED
+#  endif
+#endif
+
+#endif /* LIBATTRIBUTES_EXPORT_H */