Remove Q_BYTE_ORDER and -*-endian arguments from configures

Do not write Q_BYTE_ORDER to qconfig.h in the configures. Instead,
we #define Q_BYTE_ORDER in qprocessordetection.h, since many CPUs only
support a single endian format. For bi-endian processors, we set
Q_BYTE_ORDER depending on how the preprocessor sets __BYTE_ORDER__,
__BIG_ENDIAN__, or __LITTLE_ENDIAN__ (instead of using a compile test
to do so).

For operating systems that only support a single byte order, we can
check for Q_OS_* in addition to the preprocessor macros above. This is
possible because qprocessordetection.h is included by qglobal.h after
Q_OS_* and Q_CC_* detection has been done. Do this for Windows CE,
which is always little- endian according to MSDN.

Change-Id: I019a95e05252ef69895c4b38fbfa6ebfb6a943cd
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

config.tests/unix/endian.test

@@ -1,60 +0,0 @@
-#!/bin/sh
-
-QMKSPEC=$1
-VERBOSE=$2
-SRCDIR=$3
-OUTDIR=$4
-QMFLAGS=$5
-
-# debuggery
-[ "$VERBOSE" = "yes" ] && echo "Determining machine byte-order... ($*)"
-
-# build and run a test program
-test -d "$OUTDIR/config.tests/unix/endian" || mkdir -p "$OUTDIR/config.tests/unix/endian"
-"$OUTDIR/bin/qmake" -nocache -spec "$QMKSPEC" "QT_BUILD_TREE=$OUTDIR" $QMFLAGS "$SRCDIR/config.tests/unix/endian/endiantest.pro" -o "$OUTDIR/config.tests/unix/endian/Makefile" >/dev/null 2>&1
-cd "$OUTDIR/config.tests/unix/endian"
-
-
-ENDIAN="UNKNOWN"
-[ "$VERBOSE" = "yes" ] && $MAKE || $MAKE >/dev/null 2>&1
-
-if [ -f ./endiantest.exe ]; then
-    binary=./endiantest.exe
-else
-    binary=./endiantest
-fi
-
-
-if [ -f $binary ]; then
-    : # nop
-else
-    [ "$VERBOSE" = "yes" ] && echo "Unknown byte order!"
-    exit 2
-fi
-
-if strings - $binary | grep LeastSignificantByteFirst >/dev/null 2>&1; then
-    [ "$VERBOSE" = "yes" ] && echo "    Found 'LeastSignificantByteFirst' in binary"
-    ENDIAN="LITTLE"
-elif strings - $binary | grep MostSignificantByteFirst >/dev/null 2>&1; then
-    [ "$VERBOSE" = "yes" ] && echo "    Found 'MostSignificantByteFirst' in binary"
-    ENDIAN="BIG"
-fi
-
-# make clean as this tests is compiled for both the host and the target
-if [ "$VERBOSE" = "yes" ]; then
-    $MAKE distclean
-else
-    $MAKE distclean >/dev/null 2>&1
-fi
-
-# done
-if [ "$ENDIAN" = "LITTLE" ]; then
-    [ "$VERBOSE" = "yes" ] && echo "Using little endian."
-    exit 0
-elif [ "$ENDIAN" = "BIG" ]; then
-    [ "$VERBOSE" = "yes" ] && echo "Using big endian."
-    exit 1
-else
-    [ "$VERBOSE" = "yes" ] && echo "Unknown byte order!"
-    exit 2
-fi

config.tests/unix/endian/endiantest.cpp

@@ -1,56 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
-** Contact: http://www.qt-project.org/
-**
-** This file is part of the config.tests of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** GNU Lesser General Public License Usage
-** This file may be used under the terms of the GNU Lesser General Public
-** License version 2.1 as published by the Free Software Foundation and
-** appearing in the file LICENSE.LGPL included in the packaging of this
-** file. Please review the following information to ensure the GNU Lesser
-** General Public License version 2.1 requirements will be met:
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Nokia gives you certain additional
-** rights. These rights are described in the Nokia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU General
-** Public License version 3.0 as published by the Free Software Foundation
-** and appearing in the file LICENSE.GPL included in the packaging of this
-** file. Please review the following information to ensure the GNU General
-** Public License version 3.0 requirements will be met:
-** http://www.gnu.org/copyleft/gpl.html.
-**
-** Other Usage
-** Alternatively, this file may be used in accordance with the terms and
-** conditions contained in a signed written agreement between you and Nokia.
-**
-**
-**
-**
-**
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-// "MostSignificantByteFirst"
-short msb_bigendian[] = { 0x0000, 0x4d6f, 0x7374, 0x5369, 0x676e, 0x6966, 0x6963, 0x616e, 0x7442, 0x7974, 0x6546, 0x6972, 0x7374, 0x0000 };
-
-// "LeastSignificantByteFirst"
-short lsb_littleendian[] = { 0x0000, 0x654c, 0x7361, 0x5374, 0x6769, 0x696e, 0x6966, 0x6163, 0x746e, 0x7942, 0x6574, 0x6946, 0x7372, 0x0074, 0x0000 };
-
-int main(int, char **)
-{
-    // make sure the linker doesn't throw away the arrays
-    void (*msb_bigendian_string)() = (void (*)())msb_bigendian;
-    void (*lsb_littleendian_string)() = (void (*)())lsb_littleendian;
-    (void)msb_bigendian_string();
-    (void)lsb_littleendian_string();
-    return msb_bigendian[1] == lsb_littleendian[1];
-}

config.tests/unix/endian/endiantest.pro

@@ -1,3 +0,0 @@
-SOURCES = endiantest.cpp
-CONFIG -= qt dylib
-mac:CONFIG -= app_bundle

configure

@@ -763,8 +763,6 @@ CFG_AVX=auto
 CFG_REDUCE_RELOCATIONS=auto
 CFG_NAS=no
 CFG_ACCESSIBILITY=auto
-CFG_ENDIAN=auto
-CFG_HOST_ENDIAN=auto
 CFG_IWMMXT=no
 CFG_NEON=auto
 CFG_CLOCK_GETTIME=auto
@@ -1035,14 +1033,6 @@ while [ "$#" -gt 0 ]; do
             VAL=$1
         fi
         ;;
-    -host-*-endian)
-        VAR=host_endian
-        VAL=`echo $1 | sed "s,^-.*-\(.*\)-.*,\1,"`
-        ;;
-    -*-endian)
-        VAR=endian
-        VAL=`echo $1 | sed "s,^-\(.*\)-.*,\1,"`
-        ;;
     -qtnamespace)
         VAR="qtnamespace"
         shift
@@ -1228,24 +1218,6 @@ while [ "$#" -gt 0 ]; do
             UNKNOWN_OPT=yes
         fi
 	;;
-    endian)
-        if [ "$VAL" = "little" ]; then
-            CFG_ENDIAN="Q_LITTLE_ENDIAN"
-        elif [ "$VAL" = "big" ]; then
-            CFG_ENDIAN="Q_BIG_ENDIAN"
-        else
-            UNKNOWN_OPT=yes
-        fi
-        ;;
-    host_endian)
-        if [ "$VAL" = "little" ]; then
-            CFG_HOST_ENDIAN="Q_LITTLE_ENDIAN"
-        elif [ "$VAL" = "big" ]; then
-            CFG_HOST_ENDIAN="Q_BIG_ENDIAN"
-        else
-            UNKNOWN_OPT=yes
-        fi
-        ;;
     opengl)
         if  [ "$VAL" = "auto" ] || [ "$VAL" = "desktop" ] ||
             [ "$VAL" = "yes" ] || [ "$VAL" = "no" ] ||
@@ -3727,16 +3699,6 @@ if [ "$PLATFORM_QPA" = "yes" ]; then
     -feature-<feature> .. Compile in <feature>. The available features
                           are described in src/corelib/global/qfeatures.txt
 
-    -little-endian ...... Target platform is little endian (LSB first).
-    -big-endian ......... Target platform is big endian (MSB first).
-
-    -host-little-endian . Host platform is little endian (LSB first).
-    -host-big-endian .... Host platform is big endian (MSB first).
-
-                          You only need to specify the endianness when
-                          cross-compiling, otherwise the host
-                          endianness will be used.
-
     -no-freetype ........ Do not compile in Freetype2 support.
     -qt-freetype ........ Use the libfreetype bundled with Qt.
  *  -system-freetype .... Use libfreetype from the operating system.
@@ -5532,48 +5494,6 @@ if [ "$CFG_LIBFREETYPE" = "auto" ]; then
     fi
 fi
 
-if [ "$CFG_ENDIAN" = "auto" ]; then
-    if [ "$XPLATFORM_MINGW" = "yes" ]; then
-        CFG_ENDIAN="Q_LITTLE_ENDIAN"
-    else
-        "$unixtests/endian.test" "$XQMAKESPEC" $OPT_VERBOSE "$relpath" "$outpath" "QMAKE_LFLAGS+=$SYSROOT_FLAG"
-	F="$?"
-        if [ "$F" -eq 0 ]; then
-            CFG_ENDIAN="Q_LITTLE_ENDIAN"
-        elif [ "$F" -eq 1 ]; then
-            CFG_ENDIAN="Q_BIG_ENDIAN"
-        else
-            echo
-	    echo "The target system byte order could not be detected!"
-	    echo "Turn on verbose messaging (-v) to see the final report."
-	    echo "You can use the -little-endian or -big-endian switch to"
-	    echo "$0 to continue."
-            exit 101
-        fi
-    fi
-fi
-
-if [ "$CFG_HOST_ENDIAN" = "auto" ]; then
-    if [ "$BUILD_ON_MAC" = "yes" ]; then
-	true #leave as auto
-    else
-        "$unixtests/endian.test" "$QMAKESPEC" $OPT_VERBOSE "$relpath" "$outpath"
-	F="$?"
-        if [ "$F" -eq 0 ]; then
-            CFG_HOST_ENDIAN="Q_LITTLE_ENDIAN"
-        elif [ "$F" -eq 1 ]; then
-            CFG_HOST_ENDIAN="Q_BIG_ENDIAN"
-        else
-            echo
-	    echo "The host system byte order could not be detected!"
-	    echo "Turn on verbose messaging (-v) to see the final report."
-	    echo "You can use the -host-little-endian or -host-big-endian switch to"
-	    echo "$0 to continue."
-            exit 101
-        fi
-    fi
-fi
-
 HAVE_STL=no
 if "$unixtests/compile.test" "$XQMAKESPEC" "$QMAKE_CONFIG" $OPT_VERBOSE "$relpath" "$outpath" config.tests/unix/stl "STL" $L_FLAGS $I_FLAGS $l_FLAGS; then
     HAVE_STL=yes
@@ -6447,42 +6367,8 @@ cat >>"$outpath/src/corelib/global/qconfig.h.new" <<EOF
 #ifndef QT_EDITION
 #  define QT_EDITION $QT_EDITION
 #endif
-
-/* Machine byte-order */
-#define Q_BIG_ENDIAN 4321
-#define Q_LITTLE_ENDIAN 1234
 EOF
 
-echo "#ifdef QT_BOOTSTRAPPED" >>"$outpath/src/corelib/global/qconfig.h.new"
-if [ "$CFG_HOST_ENDIAN" = "auto" ]; then
-    cat >>"$outpath/src/corelib/global/qconfig.h.new" <<EOF
-#if defined(__BIG_ENDIAN__)
-# define Q_BYTE_ORDER Q_BIG_ENDIAN
-#elif defined(__LITTLE_ENDIAN__)
-# define Q_BYTE_ORDER Q_LITTLE_ENDIAN
-#else
-# error "Unable to determine byte order!"
-#endif
-EOF
-else
-    echo "#define Q_BYTE_ORDER $CFG_HOST_ENDIAN" >>"$outpath/src/corelib/global/qconfig.h.new"
-fi
-echo "#else" >>"$outpath/src/corelib/global/qconfig.h.new"
-if [ "$CFG_ENDIAN" = "auto" ]; then
-    cat >>"$outpath/src/corelib/global/qconfig.h.new" <<EOF
-#if defined(__BIG_ENDIAN__)
-# define Q_BYTE_ORDER Q_BIG_ENDIAN
-#elif defined(__LITTLE_ENDIAN__)
-# define Q_BYTE_ORDER Q_LITTLE_ENDIAN
-#else
-# error "Unable to determine byte order!"
-#endif
-EOF
-else
-    echo "#define Q_BYTE_ORDER $CFG_ENDIAN" >>"$outpath/src/corelib/global/qconfig.h.new"
-fi
-echo "#endif" >>"$outpath/src/corelib/global/qconfig.h.new"
-
 CFG_ARCH_STR=`echo $CFG_ARCH | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
 CFG_HOST_ARCH_STR=`echo $CFG_HOST_ARCH | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
 cat >>"$outpath/src/corelib/global/qconfig.h.new" <<EOF

configure.bat

@@ -67,9 +67,7 @@ if not exist src\corelib\global\qconfig.h (
         md src\corelib\global
         if errorlevel 1 goto exit
     )
-    echo #define Q_BIG_ENDIAN 4321 > src\corelib\global\qconfig.h
+    echo /* Generated by configure.bat - DO NOT EDIT! */ > src\corelib\global\qconfig.h
-    echo #define Q_LITTLE_ENDIAN 1234 >> src\corelib\global\qconfig.h
-    echo #define Q_BYTE_ORDER Q_LITTLE_ENDIAN >> src\corelib\global\qconfig.h
 )
 
 if not exist tools\configure (

src/corelib/global/qprocessordetection.h

@@ -53,16 +53,39 @@
     The first is always defined. Defines for the various revisions/variants are
     optional and usually dependent on how the compiler was invoked. Variants
     that are a superset of another should have a define for the superset.
+
+    In addition to the procesor family, variants, and revisions, we also set
+    Q_BYTE_ORDER appropriately for the target processor. For bi-endian
+    processors, we try to auto-detect the byte order using the __BIG_ENDIAN__,
+    __LITTLE_ENDIAN__, or __BYTE_ORDER__ preprocessor macros.
 */
 
+/* Machine byte-order, reuse preprocessor provided macros when available */
+#if defined(__ORDER_BIG_ENDIAN__)
+#  define Q_BIG_ENDIAN __ORDER_BIG_ENDIAN__
+#else
+#  define Q_BIG_ENDIAN 4321
+#endif
+#if defined(__ORDER_LITTLE_ENDIAN__)
+#  define Q_LITTLE_ENDIAN __ORDER_LITTLE_ENDIAN__
+#else
+#  define Q_LITTLE_ENDIAN 1234
+#endif
+
 /*
     Alpha family, no revisions or variants
+
+    Alpha is bi-endian, use endianness auto-detection described above.
 */
 // #elif defined(__alpha__) || defined(_M_ALPHA)
 // #  define Q_PROCESSOR_ALPHA
+// Q_BYTE_ORDER not defined, use endianness auto-detection
 
 /*
-  ARM family, known revisions: V5, V6, and V7
+    ARM family, known revisions: V5, V6, and V7
+
+    ARM is bi-endian, detect using __ARMEL__ or __ARMEB__, falling back to
+    auto-detection described above.
 */
 #if defined(__arm__) || defined(__TARGET_ARCH_ARM)
 #  define Q_PROCESSOR_ARM
@@ -88,37 +111,59 @@
         || (__TARGET_ARCH_ARM-0 >= 5)
 #    define Q_PROCESSOR_ARM_V5
 #  endif
+#  if defined(__ARMEL__)
+#    define Q_BYTE_ORDER Q_LITTLE_ENDIAN
+#  elif defined(__ARMEB__)
+#    define Q_BYTE_ORDER Q_BIG_ENDIAN
+#  else
+// Q_BYTE_ORDER not defined, use endianness auto-detection
+#endif
 
 /*
     AVR32 family, no revisions or variants
+
+    AVR32 is big-endian.
 */
 // #elif defined(__avr32__)
 // #  define Q_PROCESSOR_AVR32
+// #  define Q_BYTE_ORDER Q_BIG_ENDIAN
 
 /*
     Blackfin family, no revisions or variants
+
+    Blackfin is little-endian.
 */
 // #elif defined(__bfin__)
 // #  define Q_PROCESSOR_BLACKFIN
+// #  define Q_BYTE_ORDER Q_LITTLE_ENDIAN
 
 /*
     X86 family, known variants: 32- and 64-bit
+
+    X86 is little-endian.
 */
 #elif defined(__i386) || defined(__i386__) || defined(_M_IX86)
 #  define Q_PROCESSOR_X86
 #  define Q_PROCESSOR_X86_32
+#  define Q_BYTE_ORDER Q_LITTLE_ENDIAN
 #elif defined(__x86_64) || defined(__x86_64__) || defined(__amd64) || defined(_M_X64)
 #  define Q_PROCESSOR_X86
 #  define Q_PROCESSOR_X86_64
+#  define Q_BYTE_ORDER Q_LITTLE_ENDIAN
 
 /*
     Itanium (IA-64) family, no revisions or variants
+
+    Itanium is bi-endian, use endianness auto-detection described above.
 */
 #elif defined(__ia64) || defined(__ia64__) || defined(_M_IA64)
 #  define Q_PROCESSOR_IA64
+// Q_BYTE_ORDER not defined, use endianness auto-detection
 
 /*
     MIPS family, known revisions: I, II, III, IV, 32, 64
+
+    MIPS is bi-endian, use endianness auto-detection described above.
 */
 #elif defined(__mips) || defined(__mips__) || defined(_M_MRX000)
 #  define Q_PROCESSOR_MIPS
@@ -143,6 +188,7 @@
 #  if defined(_MIPS_ARCH_MIPS64) || defined(__mips64)
 #    define Q_PROCESSOR_MIPS_64
 #  endif
+// Q_BYTE_ORDER not defined, use endianness auto-detection
 
 /*
     Power family, known variants: 32- and 64-bit
@@ -150,6 +196,8 @@
     There are many more known variants/revisions that we do not handle/detect.
     See http://en.wikipedia.org/wiki/Power_Architecture
     and http://en.wikipedia.org/wiki/File:PowerISA-evolution.svg
+
+    Power is bi-endian, use endianness auto-detection described above.
 */
 #elif defined(__ppc__) || defined(__ppc) || defined(__powerpc__) \
       || defined(_ARCH_COM) || defined(_ARCH_PWR) || defined(_ARCH_PPC)  \
@@ -160,34 +208,60 @@
 #  else
 #    define Q_PROCESSOR_POWER_32
 #  endif
+// Q_BYTE_ORDER not defined, use endianness auto-detection
 
 /*
     S390 family, known variant: S390X (64-bit)
+
+    S390 is big-endian.
 */
 // #elif defined(__s390__)
 // #  define Q_PROCESSOR_S390
 // #  if defined(__s390x__)
 // #    define Q_PROCESSOR_S390_X
 // #  endif
+// #  define Q_BYTE_ORDER Q_BIG_ENDIAN
 
 /*
     SuperH family, optional revision: SH-4A
+
+    SuperH is bi-endian, use endianness auto-detection descrived above.
 */
 // #elif defined(__sh__)
 // #  define Q_PROCESSOR_SH
 // #  if defined(__sh4a__)
 // #    define Q_PROCESSOR_SH_4A
 // #  endif
+// Q_BYTE_ORDER not defined, use endianness auto-detection
 
 /*
     SPARC family, optional revision: V9
+
+    SPARC is big-endian only prior to V9, while V9 is bi-endian with big-endian
+    as the default byte order. Assume all SPARC systems are big-endian.
 */
 // #elif defined(__sparc__)
 // #  define Q_PROCESSOR_SPARC
 // #  if defined(__sparc_v9__)
 // #    define Q_PROCESSOR_SPARC_V9
 // #  endif
+// #  define Q_BYTE_ORDER Q_BIG_ENDIAN
 
 #endif
 
+// Some processors support either endian format, try to detect which we are using.
+#if !defined(Q_BYTE_ORDER)
+#  if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == Q_BIG_ENDIAN || __BYTE_ORDER__ == Q_LITTLE_ENDIAN)
+// Reuse __BYTE_ORDER__ as-is, since our Q_*_ENDIAN #defines match the preprocessor defaults
+#    define Q_BYTE_ORDER __BYTE_ORDER__
+#  elif defined(__BIG_ENDIAN__)
+#    define Q_BYTE_ORDER Q_BIG_ENDIAN
+#  elif defined(__LITTLE_ENDIAN__)  \
+        || defined(Q_OS_WINCE) // Windows CE is always little-endian according to MSDN.
+#    define Q_BYTE_ORDER Q_LITTLE_ENDIAN
+#  else
+#    error "Unable to determine byte order!"
+#  endif
+#endif
+
 #endif // QPROCESSORDETECTION_H

tools/configure/configureapp.cpp

@@ -2704,10 +2704,6 @@ void Configure::generateConfigfiles()
             tmpStream << "#define QT_BUILD_INTERNAL" << endl;
             tmpStream << endl;
         }
-        tmpStream << "/* Machine byte-order */" << endl;
-        tmpStream << "#define Q_BIG_ENDIAN 4321" << endl;
-        tmpStream << "#define Q_LITTLE_ENDIAN 1234" << endl;
-        tmpStream << "#define Q_BYTE_ORDER Q_LITTLE_ENDIAN" << endl;
 
         if (dictionary[ "QPA" ] == "yes")
             tmpStream << endl << "#define Q_WS_QPA" << endl;