From 72f3e9b25a3db297334a7e22cb825523035850de Mon Sep 17 00:00:00 2001
From: "Markus F.X.J. Oberhumer" <markus@oberhumer.com>
Date: Tue, 3 Jan 2023 15:11:11 +0100
Subject: [PATCH] all: require C++17

---
 .github/workflows/ci.yml | 2 +-
 CMakeLists.txt           | 8 ++++----
 Makefile                 | 2 ++
 compile_flags.txt        | 1 +
 src/conf.h               | 8 ++------
 5 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b9bad471..9a7cb6c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -286,7 +286,7 @@ jobs:
           set s=%H%\src
           cat .GITREV.txt
           set /p GITREV=<.GITREV.txt
-          cl -MT -EHsc -J -O2 -W4 -WX -DUPX_VERSION_GITREV="""%GITREV%""" %DEFS% -I%H%\vendor -Feupx.exe %s%\*.cpp %s%\util\*.cpp %BDIR%\ucl\ucl.lib %BDIR%\zlib\zlib.lib /link setargv.obj
+          cl -std:c++17 -Zc:__cplusplus -EHsc -J -O2 -W4 -WX -DUPX_VERSION_GITREV="""%GITREV%""" %DEFS% -I%H%\vendor -Feupx.exe %s%\*.cpp %s%\util\*.cpp %BDIR%\ucl\ucl.lib %BDIR%\zlib\zlib.lib /link setargv.obj
       - name: 'Make artifact'
         shell: bash
         run: |
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a8c70006..eedf5a61 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.4.3 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.8 FATAL_ERROR)
 
 # compilation config options
 if(NOT IS_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/.git")
@@ -110,8 +110,8 @@ set_property(TARGET upx_vendor_zlib PROPERTY C_STANDARD 11)
 file(GLOB upx_SOURCES "src/*.cpp" "src/util/*.cpp")
 list(SORT upx_SOURCES)
 add_executable(upx ${upx_SOURCES})
-#target_compile_features(upx PRIVATE cxx_std_14)
-set_property(TARGET upx PROPERTY CXX_STANDARD 14)
+#target_compile_features(upx PRIVATE cxx_std_17)
+set_property(TARGET upx PROPERTY CXX_STANDARD 17)
 target_link_libraries(upx upx_vendor_ucl upx_vendor_zlib)
 
 if(UPX_CONFIG_DISABLE_WERROR)
@@ -190,7 +190,7 @@ if(GITREV_SHORT)
 endif()
 upx_sanitize_target(${t})
 if(MSVC)
-    target_compile_options(${t} PRIVATE -EHsc -J -W4 ${warn_WX})
+    target_compile_options(${t} PRIVATE -Zc:__cplusplus -EHsc -J -W4 ${warn_WX})
 else()
     target_compile_options(${t} PRIVATE
         -Wall -Wextra -Wcast-align -Wcast-qual -Wmissing-declarations -Wpointer-arith
diff --git a/Makefile b/Makefile
index 71635db4..f0ec3b05 100644
--- a/Makefile
+++ b/Makefile
@@ -129,3 +129,5 @@ endif
 ifeq ($(wildcard ./vendor/zlib/crc32.c),)
   $(error ERROR: missing git submodule; run 'git submodule update --init')
 endif
+
+.NOTPARALLEL: # top-level Makefile is sequential, but actual builds use "cmake --parallel"
diff --git a/compile_flags.txt b/compile_flags.txt
index ed6dbff7..486ef41c 100644
--- a/compile_flags.txt
+++ b/compile_flags.txt
@@ -1,3 +1,4 @@
+-std=gnu++17
 -Ivendor
 -fno-strict-aliasing
 -fno-strict-overflow
diff --git a/src/conf.h b/src/conf.h
index 8bc10e69..00b0b9b9 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -29,12 +29,8 @@
 #ifndef UPX_CONF_H__
 #define UPX_CONF_H__ 1
 
-#if defined(__cplusplus)
-#  if (__cplusplus >= 201402L)
-#  elif defined(_MSC_VER) && defined(_MSVC_LANG) && (_MSVC_LANG+0 >= 201402L)
-#  else
-#    error "C++ 14 is required"
-#  endif
+#if !(__cplusplus+0 >= 201703L)
+#  error "C++ 17 is required"
 #endif
 
 #include "version.h"