Remove support for disabling C++11 support in configure

Qt now requires it.

We could try and run the common/c++11 test for MSVC too, but we know it
passes, so we won't bother and thus slow down the configure step.

Change-Id: Ib056b47dde3341ef9a52ffff13ef6b53b9f8bb65
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

2 files changed, 22 insertions, 64 deletions

diff --git a/configure b/configure
index b9fb69a11b..503cca3c67 100755
--- a/configure
+++ b/configure
@@ -2253,28 +2253,19 @@ while [ "$#" -gt 0 ]; do
             UNKNOWN_OPT=yes
         fi
         ;;
-    c++11)
-        if [ "$VAL" = "yes" ]; then
-            CFG_STDCXX="c++11"
-        elif [ "$VAL" = "no" ]; then
-            CFG_STDCXX="c++98"
-        else
-            UNKNOWN_OPT=yes
-        fi
-        ;;
     c++std)
         case "$VAL" in
-            c++98|c++11|c++14|c++1z|auto)
+            c++11|c++14|c++1z|auto)
                 CFG_STDCXX="$VAL"
                 ;;
-            98|11|14|1z)
+            11|14|1z)
                 CFG_STDCXX="c++$VAL"
                 ;;
             1y|c++1y)
                 CFG_STDCXX="c++14"
                 ;;
             *)
-                echo >&2 "Invalid C++ edition: $VAL; valid options are: c++98 c++11 c++14 c++1z auto"
+                echo >&2 "Invalid C++ edition: $VAL; valid options are: c++11 c++14 c++1z auto"
                 ERROR=yes
                 ;;
         esac
@@ -2450,7 +2441,7 @@ Configure options:
     -confirm-license ... Automatically acknowledge the license (use with
                          either -opensource or -commercial)
 
-    -c++std <edition> .. Compile Qt with C++ standard edition (c++98, c++11, c++14, c++1z)
+    -c++std <edition> .. Compile Qt with C++ standard edition (c++11, c++14, c++1z)
                          Default: highest supported
 
  *  -shared ............ Create and use shared Qt libraries.
@@ -4411,20 +4402,11 @@ if [ "$CFG_SEPARATE_DEBUG_INFO" = "yes" ]; then
 fi
 
 # Detect C++11 & up support
-# Configure detects compiler features based on cross compiler, so we need
-# to explicitly disable C++11 on Mac to avoid breaking builds where the
-# host compiler does not support it.
 stdcxx_error=false
-if [ "$BUILD_ON_MAC" = "yes" ] && [ "$XPLATFORM_ANDROID" = "yes" ]; then
-    CFG_STDCXX="c++98"
-elif [ "$CFG_STDCXX" = "c++98" ]; then
-    : # CFG_STDCXX is correct
-elif ! compileTest common/c++11 "C++11"; then
-    if [ "$CFG_STDCXX" != "auto" ]; then
-        stdcxx_error=true
-    else
-        CFG_STDCXX="c++98"
-    fi
+if ! compileTest common/c++11 "C++11"; then
+    echo "ERROR: Qt requires a C++11 compiler and yours does not seem to be that."
+    echo "Please upgrade."
+    exit 1
 elif [ "$CFG_STDCXX" = "c++11" ]; then
     : # CFG_STDCXX is correct
 elif ! compileTest common/c++14 "C++14"; then
@@ -6267,13 +6249,12 @@ fi
 # ask for all that hasn't been auto-detected or specified in the arguments
 #-------------------------------------------------------------------------------
 
-if [ "$CFG_STDCXX" != "c++98" ]; then
-    QT_CONFIG="$QT_CONFIG c++11"
-    if [ "$CFG_STDCXX" != "c++11" ]; then
-        QT_CONFIG="$QT_CONFIG c++14"
-        if [ "$CFG_STDCXX" != "c++14" ]; then
-            QT_CONFIG="$QT_CONFIG c++1z"
-        fi
+# Set "c++11" unconditionally, as lots of code does contains(QT_CONFIG, c++11)
+QT_CONFIG="$QT_CONFIG c++11"
+if [ "$CFG_STDCXX" != "c++11" ]; then
+    QT_CONFIG="$QT_CONFIG c++14"
+    if [ "$CFG_STDCXX" != "c++14" ]; then
+        QT_CONFIG="$QT_CONFIG c++1z"
     fi
 fi
 
@@ -7611,20 +7592,6 @@ EOF
 fi
 
 #-------------------------------------------------------------------------------
-# check if the user passed the deprecated -no-c++11 / --c++-level=c++98 option
-#-------------------------------------------------------------------------------
-if [ "$CFG_STDCXX" = "c++98" ]; then
-cat <<EOF
-
-        NOTICE: The -no-c++11 / --c++-level=c++98 option is deprecated.
-
-        Qt 5.7 will require C++11 support. The options are in effect for this
-        Qt 5.6 build, but you should update your build scripts to remove the
-        option and, if necessary, upgrade your compiler.
-EOF
-fi
-
-#-------------------------------------------------------------------------------
 # finally save the executed command to another script
 #-------------------------------------------------------------------------------
 if [ `basename $0` != "config.status" ]; then
diff --git a/tools/configure/configureapp.cpp b/tools/configure/configureapp.cpp
index 08afc51bc4..bdfaeda052 100644
--- a/tools/configure/configureapp.cpp
+++ b/tools/configure/configureapp.cpp
@@ -468,25 +468,21 @@ void Configure::parseCmdLine()
             dictionary[ "COMPILE_EXAMPLES" ] = "no";
         }
 
-        else if (configCmdLine.at(i) == "-c++11")
-            dictionary[ "C++STD" ] = "c++11";
-        else if (configCmdLine.at(i) == "-no-c++11")
-            dictionary[ "C++STD" ] = "c++98";
         else if (configCmdLine.at(i) == "-c++std") {
             ++i;
             if (i == argCount)
                 break;
 
             QString level = configCmdLine.at(i);
-            if (level == "c++98" || level == "c++11" || level == "c++14" || level == "c++1z"
+            if (level == "c++11" || level == "c++14" || level == "c++1z"
                     || level == "auto") {
                 dictionary[ "C++STD" ] = level;
-            } else if (level == "98" || level == "11" || level == "14" || level == "1z") {
+            } else if (level == "11" || level == "14" || level == "1z") {
                 dictionary[ "C++STD" ] = "c++" + level;
             } else {
                 dictionary[ "DONE" ] = "error";
                 cout << "ERROR: invalid C++ standard " << level
-                     << "; valid options are: c++98 c++11 c++14 c++1z auto" << endl;
+                     << "; valid options are: c++11 c++14 c++1z auto" << endl;
                 return;
             }
         }
@@ -1824,7 +1820,7 @@ bool Configure::displayHelp()
         desc("OPENSOURCE", "opensource", "-opensource",   "Compile and link the Open-Source Edition of Qt.");
         desc("COMMERCIAL", "commercial", "-commercial",   "Compile and link the Commercial Edition of Qt.\n");
 
-        desc(        "-c++std <edition>",               "Compile Qt with C++ standard edition (c++98, c++11, c++14, c++1z)\n"
+        desc(        "-c++std <edition>",               "Compile Qt with C++ standard edition (c++11, c++14, c++1z)\n"
                                                         "Default: highest supported. This option is not supported for MSVC.\n");
 
         desc("USE_GOLD_LINKER", "yes", "-use-gold-linker",                  "Link using the GNU gold linker (gcc only).");
@@ -2401,7 +2397,10 @@ void Configure::autoDetection()
 
     if (dictionary["C++STD"] == "auto" && !dictionary["QMAKESPEC"].contains("msvc")) {
         if (!tryCompileProject("common/c++11")) {
-            dictionary["C++STD"] = "c++98";
+            dictionary["DONE"] = "error";
+            cout << "ERROR: Qt requires a C++11 compiler and yours does not seem to be that." << endl
+                 << "Please upgrade." << endl;
+            return;
         } else if (!tryCompileProject("common/c++14")) {
             dictionary["C++STD"] = "c++11";
         } else if (!tryCompileProject("common/c++1z")) {
@@ -4059,14 +4058,6 @@ void Configure::displayConfig()
              << "will be the same unless you are cross-compiling)." << endl
              << endl;
     }
-    if (dictionary["C++STD"] == "c++98") {
-        sout << endl
-             << "NOTE: The -no-c++11 / -c++-level c++98 option is deprecated." << endl
-             << endl
-             << "Qt 5.7 will require C++11 support. The options are in effect for this" << endl
-             << "Qt 5.6 build, but you should update your build scripts to remove the" << endl
-             << "option and, if necessary, upgrade your compiler." << endl;
-    }
     if (!dictionary["PREFIX_COMPLAINTS"].isEmpty()) {
         sout << endl
              << dictionary["PREFIX_COMPLAINTS"] << endl