Add a simple Qt 6/CMake-compatible script a la includemocs.py

Perl is dead and I don't speak Python, so if someone wants to port it,
be my guest. I needed something that I can use to roll out includemocs
across all Qt modules, and this is it. It works for me™, so I don't
expect to do much development with it.

This is an automated committer script I've been using so far:

    # SRCDIR=~~~
    # BUILDDIR=~~~~
    cd $BUILDDIR
    find */src -name mocs_compilation.cpp | while read FILE; do
        if grep -qsE '^#include' "$FILE"; then
            DIR="$(dirname "$FILE")"
            LIB="$(basename "$DIR")"
            case "$LIB" in
            Q*)
                LIB="${LIB%%_autogen}"
                ;;
            *)
                LIB="Qt${LIB%%_autogen}"
                ;;
            esac
            DIR="${DIR%/*}"
            path/to/includemocs6.sh "$SRCROOT/$DIR" "$DIR" "$FILE"
            (cd "$SRCROOT/$DIR" && git commit -am "$LIB: includemocs

$(cat "$SRCROOT/commit-msg.txt")" --no-edit)
        fi
    done

If the script cannot associate a moc file with a cpp file, it will
print a warning and continue.

The script tries to include the moc-file right after the
QT_END_NAMESPACE to work around many TUs ending in an #endif from some
#if QT_CONFIG or other. If there's no QT_END_NAMESPACE, it appends
the include and prints a warning.

Fixes: QTBUG-102886
Pick-to: 6.3 6.2
Change-Id: I16c5a9f845777ea2e82f15611b4fdd32f98ce0bb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

util/includemocs/includemocs6.sh

@@ -0,0 +1,119 @@
+#!/bin/bash
+#############################################################################
+##
+## Copyright (C) 2022 The Qt Company Ltd.
+## Contact: https://www.qt.io/licensing/
+##
+## This file is the build configuration utility of the Qt Toolkit.
+##
+## $QT_BEGIN_LICENSE:GPL-EXCEPT$
+## Commercial License Usage
+## Licensees holding valid commercial Qt licenses may use this file in
+## accordance with the commercial license agreement provided with the
+## Software or, alternatively, in accordance with the terms contained in
+## a written agreement between you and The Qt Company. For licensing terms
+## and conditions see https://www.qt.io/terms-conditions. For further
+## information use the contact form at https://www.qt.io/contact-us.
+##
+## GNU General Public License Usage
+## Alternatively, this file may be used under the terms of the GNU
+## General Public License version 3 as published by the Free Software
+## Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+## included in the packaging of this file. Please review the following
+## information to ensure the GNU General Public License requirements will
+## be met: https://www.gnu.org/licenses/gpl-3.0.html.
+##
+## $QT_END_LICENSE$
+##
+#############################################################################
+
+VERBOSE=0
+CONTINUE_ON_FAILURE=1
+
+function warn() {
+    echo "$@" >&2
+}
+
+function log() {
+    [[ "$VERBOSE" -eq 1 ]] && warn "$@"
+}
+
+function die() {
+    warn "$@"
+    exit 1
+}
+
+function continue_or_die() {
+    if [[ "$CONTINUE_ON_FAILURE" -eq 1 ]] ; then
+        warn "$@"
+    else
+        die "$@"
+    fi
+}
+
+function usage() {
+    die "usage: includemocs6.sh <srcdir> <builddir> <mocs_compilation_file>"
+}
+
+#
+# sanity checks:
+#
+
+[[ ${#@} -eq 3 ]] || usage
+
+SRCDIR="$1"
+BUILDDIR="$2"
+MOCS_COMPILATION_FILE="$3"
+
+[[ -d "$BUILDDIR" ]] || die "Build dir \"$BUILDDIR\" doesn't exist or isn't a directory."
+[[ -d "$SRCDIR"  ]] || die "Source dir \"SRCDIR\" doesn't exist or isn't a directory."
+[[ -f "$MOCS_COMPILATION_FILE" ]] || die "MOCs-compilation file \"$MOCS_COMPILATION_FILE\" doesn't exist or isn't a file."
+
+#
+# extract the files included by the mocs_compilation.cpp
+#
+
+# lines look like this:
+#   #include "SOFJASFD/moc_foo.cpp"
+#   #include "JFEJGKKS/moc_foo_p.cpp"
+# extracting moc_foo(_p).cpp:
+grep -E '^#include' "$MOCS_COMPILATION_FILE" | cut -d\" -f2 | cut -d/ -f2 | while read MOCFILE; do
+    log "MOCFILE=$MOCFILE"
+    C1="${MOCFILE##moc_}"              # foo.cpp or foo_p.cpp or foo_p_p.cpp
+    case "$MOCFILE" in
+        moc_*_p_p.cpp)
+            C2="${C1/_p.cpp/.cpp}"     # foo_p.cpp
+            C3="${C2/_p.cpp/.cpp}"     # foo.cpp
+            CANDIDATES=("$C1" "$C2" "$C3")
+            ;;
+        moc_*_p.cpp)
+            C2="${C1/_p.cpp/.cpp}"     # foo.cpp
+            CANDIDATES=("$C1" "$C2")
+            ;;
+        moc_*.cpp)
+            CANDIDATES=("$C1")
+            ;;
+        *)
+            die "Don't know how to handle moc-file \"$MOCFILE\"..."
+            ;;
+    esac
+    log "CANDIDATES=(${CANDIDATES[@]})"
+    for CANDIDATE in "${CANDIDATES[@]}"; do
+        CPPFILE="$(find "$SRCDIR" -name "$CANDIDATE")"
+        log "CPPFILE=$CPPFILE"
+        [[ -f "$CPPFILE" ]] && break
+    done
+    if [[ -f "$CPPFILE" ]] ; then
+        log "going to include $MOCFILE into $CPPFILE"
+        if ! grep -qE '^QT_END_NAMESPACE$' "$CPPFILE"; then
+            warn "Can't find QT_END_NAMESPACE in \"$CPPFILE\", simply appending the #include. Please check placement manually."
+            echo "#include \"$MOCFILE\"" >> "$CPPFILE" || die "Failed to write to \"$CPPFILE\""
+        else
+            sed -i -e "1,/QT_END_NAMESPACE/ s/QT_END_NAMESPACE/QT_END_NAMESPACE\n\n#include \"$MOCFILE\"/" "$CPPFILE" || die "Failed to includemoc \"$MOCFILE\" into \"$CPPFILE\"."
+        fi
+    else
+        continue_or_die "Can't find a cpp file for $MOCFILE (not looking for .cxx .cc etc)."
+    fi
+done
+
+exit 0