Add --system-qtdeps build mode.

In this mode, system-provided libraries will be used for all of
Qt's dependencies, but Qt and QtWebkit themselves are still the
bundled copies.  This mode actually works.

Now that this mode exists, disable fontconfig in the "everything
bundled" mode, because it drags in the system freetype and several
other system libraries.  (There is no bundled fontconfig.)

Part of issue #12467.

build.sh

@@ -34,6 +34,7 @@ if [[ "$COMPILE_JOBS" -gt 8 ]]; then
 fi
 
 SILENT=''
+QTDEPLIBS=bundled
 QTCORE=bundled
 QTWEBKIT=bundled
 
@@ -57,10 +58,15 @@ until [ -z "$1" ]; do
         "--silent")
             SILENT=silent
             shift;;
+        "--system-qtdeps")
+            QTDEPLIBS=system
+            shift;;
         "--system-qt")
+            QTDEPLIBS=system
             QTCORE=system
             shift;;
         "--system-qtwebkit")
+            QTDEPLIBS=system
             QTCORE=system
             QTWEBKIT=system
             shift;;
@@ -71,7 +77,8 @@ until [ -z "$1" ]; do
             echo "  --qt-config CONFIG          Specify extra config options to be used when configuring Qt"
             echo "  --jobs NUM                  How many parallel compile jobs to use. Defaults to 4."
             echo "  --silent                    Produce less verbose output."
-            echo "  --system-qt                 Use system-provided Qt core libraries. EXPERIMENTAL, build may not succeed."
+            echo "  --system-qtdeps             Use system-provided libraries for all of Qt's dependencies (e.g. freetype, libpng).  EXPERIMENTAL."
+            echo "  --system-qt                 Use system-provided Qt core libraries. EXPERIMENTAL, build may not succeed.  Implies --system-qtdeps."
             echo "  --system-qtwebkit           Use system-provided QtWebkit.  EXPERIMENTAL, build may not succeed.  Implies --system-qt."
             echo
             exit 0
@@ -125,8 +132,7 @@ echo
 
 if [[ "$QTCORE" == "bundled" ]]; then
     export QMAKE=$PWD/src/qt/qtbase/bin/qmake
-    export SQLITE3SRCDIR=$PWD/src/qt/qtbase/src/3rdparty/sqlite/
-    ( cd src/qt && ./preconfig.sh $QT_CFG )
+    ( cd src/qt && ./preconfig.sh $QTDEPLIBS $QT_CFG )
 
     echo
     echo "Building Qt..."
@@ -144,6 +150,9 @@ if [[ "$QTWEBKIT" == "bundled" ]]; then
     echo
     echo "Building QtWebkit..."
     echo
+    if [[ "$QTDEPLIBS" == "bundled" ]]; then
+        export SQLITE3SRCDIR=$PWD/src/qt/qtbase/src/3rdparty/sqlite/
+    fi
     ( cd src/qt/qtwebkit &&
         $QMAKE $QMAKE_ARGS &&
         make -j$COMPILE_JOBS $MAKE_S )

src/qt/preconfig.sh

@@ -2,14 +2,22 @@
 
 set -e
 
+if [[ $1 == "system" ]] || [[ $1 == "bundled" ]]; then
+    QTDEPLIBS=$1
+    shift
+else
+    QTDEPLIBS=bundled
+fi
+
 QT_CFG=''
 QT_CFG+=' -opensource'          # Use the open-source license
 QT_CFG+=' -confirm-license'     # Silently acknowledge the license confirmation
-QT_CFG+=' -v'                   # Makes it easier to see what header dependencies are missing
+QT_CFG+=' -v'                   # Reveal what header dependencies are missing
 QT_CFG+=' -static'              # No shared libraries
 QT_CFG+=' -qpa phantom'         # Default to our custom QPA platform
 QT_CFG+=' -release'             # Build only for release (no debugging support)
 QT_CFG+=' -nomake examples'     # Don't build any examples
+QT_CFG+=' -no-compile-examples' # Seriously, don't build any examples
 QT_CFG+=' -nomake tools'        # Don't build the tools
 
 if [[ $OSTYPE == darwin* ]]; then
@@ -40,32 +48,61 @@ QT_CFG+=' -no-libudev'
 QT_CFG+=' -no-linuxfb'
 QT_CFG+=' -no-mtdev'
 QT_CFG+=' -no-nis'
-QT_CFG+=' -no-pkg-config'
 QT_CFG+=' -no-sm'
 QT_CFG+=' -no-xcb'
 QT_CFG+=' -no-xcb-xlib'
 QT_CFG+=' -no-xinerama'
+QT_CFG+=' -no-xinput2'
 QT_CFG+=' -no-xkb'
+QT_CFG+=' -no-xrender'
 
-# Use the bundled libraries, vs system-installed
-# Note: pcre cannot be disabled, even though webkit has its own regex engine
-# Note: as best I can tell, webkitcore has a hard dependency on sqlite
-QT_CFG+=' -qt-harfbuzz'
-QT_CFG+=' -qt-libjpeg'
-QT_CFG+=' -qt-libpng'
-QT_CFG+=' -qt-pcre'
-QT_CFG+=' -qt-sql-sqlite'
-QT_CFG+=' -qt-zlib'
+# These are also unnecessary, but it's not possible to turn them off.
+#QT_CFG+=' -no-pulseaudio'
+#QT_CFG+=' -no-xlib'
 
-# Explicitly compile with support for certain optional features enabled,
-# so the build will fail if headers are missing.
+# Explicitly compile with support for OpenSSL enabled, so the build
+# will fail if headers are missing.
 QT_CFG+=' -openssl'
 
+# ICU support in QtBase is reported to be unnecessary for Darwin.
 if [[ $OSTYPE != darwin* ]]; then
-    # These are reported to be unnecessary and/or not work correctly
-    # on Darwin.
     QT_CFG+=' -icu'
-    QT_CFG+=' -fontconfig'
+fi
+
+# PCRE cannot be disabled, even though WebKit has its own regex
+# engine.  The Qt probe for system PCRE is hardwired to look for
+# -lpcre16, which is ancient and not present on current Linux
+# installs.
+QT_CFG+=' -qt-pcre'
+
+if [[ $QTDEPLIBS == bundled ]]; then
+    # Use the bundled libraries.
+    # Note: as best I can tell, webkitcore has a hard dependency on sqlite.
+    QT_CFG+=' -no-pkg-config'
+    QT_CFG+=' -qt-freetype'
+    QT_CFG+=' -qt-harfbuzz'
+    QT_CFG+=' -qt-libjpeg'
+    QT_CFG+=' -qt-libpng'
+    QT_CFG+=' -qt-sql-sqlite'
+    QT_CFG+=' -qt-zlib'
+
+    # There is no bundled copy of fontconfig, and if activated it will
+    # pull in the system copies of several of the above libraries.
+    QT_CFG+=' -no-fontconfig'
+
+else
+    # Use system-provided libraries.
+    QT_CFG+=' -system-freetype'
+    QT_CFG+=' -system-harfbuzz'
+    QT_CFG+=' -system-libjpeg'
+    QT_CFG+=' -system-libpng'
+    QT_CFG+=' -system-sqlite -sql-sqlite'
+    QT_CFG+=' -system-zlib'
+
+    # Fontconfig is reported to not work correctly on Darwin.
+    if [[ $OSTYPE != darwin* ]]; then
+        QT_CFG+=' -fontconfig'
+    fi
 fi
 
 # Useless styles