CMake: Generate and use a wrapper script for stripping binaries

MinGW 11.2.0 comes with a strip.exe that strips the ".gnu_debuglink"
section in binaries, a section that is needed for the separate debug
information feature.

binutils version 2.34 mentions the feature for the first time:
https://sourceware.org/binutils/docs-2.34/binutils/strip.html#strip

To ensure the debuglink section is preserved, generate a shell wrapper
that calls the original strip binary with an extra option to keep the
required section.

To determine if the option is supported, we build a real shared library
on which strip will be called with the --keep-section option.
If the option is not supported, a wrapper is not generated and the
stock strip binary is used.

This logic only applies when targeting Linux and MinGW + a shared
library Qt. For other targets, the stock strip binary is used.

Developers can opt out of this logic by passing
-DQT_NO_STRIP_WRAPPER=TRUE when configuring each Qt repo.

Pick-to: 6.2 6.3
Fixes: QTBUG-101653
Change-Id: Idd213d48d087d3c9600c853362aebaba348cde33
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>

2 files changed, 37 insertions, 0 deletions

diff --git a/config.tests/binary_for_strip/CMakeLists.txt b/config.tests/binary_for_strip/CMakeLists.txt
new file mode 100644
index 0000000000..810e303629
--- /dev/null
+++ b/config.tests/binary_for_strip/CMakeLists.txt
@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.16)
+project(proj LANGUAGES CXX)
+add_library(lib1 SHARED lib1.cpp)
+
+add_custom_target(print_lib_path ALL
+    COMMAND ${CMAKE_COMMAND} -E echo "###$<TARGET_FILE:lib1>###"
+)
+add_dependencies(print_lib_path lib1)
diff --git a/config.tests/binary_for_strip/lib1.cpp b/config.tests/binary_for_strip/lib1.cpp
new file mode 100644
index 0000000000..b387dc4c4e
--- /dev/null
+++ b/config.tests/binary_for_strip/lib1.cpp
@@ -0,0 +1,29 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the utils 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+int libfunc() { return 0; }