From e88864578a881c0a14ef2dc958ee52e2aa036134 Mon Sep 17 00:00:00 2001
From: Alexandru Croitor <alexandru.croitor@qt.io>
Date: Tue, 28 May 2019 16:19:42 +0200
Subject: [PATCH] Generate the c++xx standard features instead of skipping them

The features are reused in qtdeclarative (and maybe somewhere else
too), so they should be present. We can still map the conditions
to proper CMake compile feature tests.

Change-Id: I4d307d29d4d293cc23ab005b195ea346087c7162
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
Reviewed-by: Qt CMake Build Bot
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
---
 configure.cmake                   | 39 ++++++++++++++++++++++++++++++-
 util/cmake/configurejson2cmake.py |  6 -----
 util/cmake/helper.py              |  5 +++-
 3 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/configure.cmake b/configure.cmake
index 957d7fb13b0..330c5347c54 100644
--- a/configure.cmake
+++ b/configure.cmake
@@ -15,6 +15,27 @@ qt_find_package(Libudev PROVIDED_TARGETS PkgConfig::Libudev)
 
 #### Tests
 
+# c++2a
+qt_config_compile_test(cxx2a
+    LABEL "C++2a support"
+"#if __cplusplus > 201703L
+// Compiler claims to support experimental C++2a, trust it
+#else
+#  error __cplusplus must be > 201703L (the value for C++17)
+#endif
+
+
+int main(int argc, char **argv)
+{
+    (void)argc; (void)argv;
+    /* BEGIN TEST: */
+
+    /* END TEST: */
+    return 0;
+}
+"# FIXME: qmake: CONFIG += c++11 c++14 c++1z c++2a
+)
+
 # precompile_header
 qt_config_compile_test(precompile_header
     LABEL "precompiled header support"
@@ -245,9 +266,25 @@ qt_feature("framework" PUBLIC
 qt_feature_definition("framework" "QT_MAC_FRAMEWORK_BUILD")
 qt_feature("largefile"
     LABEL "Large file support"
-    CONDITION NOT ANDROID AND NOT INTEGRITY AND NOT WINRT
+    CONDITION NOT ANDROID AND NOT INTEGRITY AND NOT WINRT AND NOT rtems
 )
 qt_feature_definition("largefile" "QT_LARGEFILE_SUPPORT" VALUE "64")
+qt_feature("cxx11" PUBLIC
+    LABEL "C++11"
+)
+qt_feature("cxx14" PUBLIC
+    LABEL "C++14"
+    CONDITION QT_FEATURE_cxx11 AND $<COMPILE_FEATURES:cxx_std_14>
+)
+qt_feature("cxx1z" PUBLIC
+    LABEL "C++17"
+    CONDITION QT_FEATURE_cxx14 AND $<COMPILE_FEATURES:cxx_std_17>
+)
+qt_feature("cxx2a" PUBLIC
+    LABEL "C++2a"
+    AUTODETECT OFF
+    CONDITION QT_FEATURE_cxx1z AND TEST_cxx2a
+)
 qt_feature("reduce_exports" PRIVATE
     LABEL "Reduce amount of exported symbols"
     CONDITION NOT WIN32 AND CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY
diff --git a/util/cmake/configurejson2cmake.py b/util/cmake/configurejson2cmake.py
index 148109e2a4b..890d4dfc5fe 100755
--- a/util/cmake/configurejson2cmake.py
+++ b/util/cmake/configurejson2cmake.py
@@ -615,13 +615,7 @@ def parseFeature(ctx, feature, data, cm_fh):
         'alloc_malloc_h': None,
         'alloc_stdlib_h': None,
         'build_all': None,
-        'c++11': None,   # C and C++ versions
         'c11': None,
-        'c++14': None,
-        'c++1y': None,
-        'c++1z': None,
-        # FIXME: used in qtdeclarative, drop when we require C++14
-        'cxx14_make_unique': None,
         'c89': None,
         'c99': None,
         'ccache': None,
diff --git a/util/cmake/helper.py b/util/cmake/helper.py
index bb2b239aa04..8f24a49d6bf 100644
--- a/util/cmake/helper.py
+++ b/util/cmake/helper.py
@@ -302,7 +302,10 @@ def find_library_info_for_target(targetName: str) -> typing.Optional[LibraryMapp
 
 
 def featureName(input: str) -> str:
-    return re.sub(r'[^a-zA-Z0-9_]', '_', input)
+    replacement_char = '_'
+    if input.startswith('c++'):
+        replacement_char = 'x'
+    return re.sub(r'[^a-zA-Z0-9_]', replacement_char, input)
 
 
 def map_qt_library(lib: str) -> str: