Re: [PATCH v4 3/3] Makefile: restrict -Wpedantic and -Wno-pedantic-ms-format better

> 6a8cbc41ba (developer: enable pedantic by default, 2021-09-03)
> enables pedantic mode in as many compilers as possible to help gather
> feedback on future tightening, so lets do so.
> 
> -Wpedantic is missing in some really old gcc 4 versions so lets restrict
> it to gcc5 and clang4 (it does work in clang3 AFAIK, but it will be
> unlikely that a developer will use such an old compiler anyway).
> 
> MinGW gcc is the only one which has -Wno-pedantic-ms-format, and while
> that is available also in older compilers, the Windows SDK provides gcc10
> so let's aim for that.
> 
> Note that in order to target the flag to only Windows, additional changes
> were needed in config.mak.uname to propagate the OS detection which also
> did some minor refactoring, but which is functionaly equivalent.
> 
> Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
> ---
>  config.mak.dev   | 7 ++++++-
>  config.mak.uname | 8 +++++++-
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/config.mak.dev b/config.mak.dev
> index cdf043c52b..7673fed114 100644
> --- a/config.mak.dev
> +++ b/config.mak.dev
> @@ -6,14 +6,19 @@ ifeq ($(filter no-error,$(DEVOPTS)),)
>  DEVELOPER_CFLAGS += -Werror
>  SPARSE_FLAGS += -Wsparse-error
>  endif
> +
>  DEVELOPER_CFLAGS += -Wall
>  ifeq ($(filter no-pedantic,$(DEVOPTS)),)
>  DEVELOPER_CFLAGS += -pedantic
> +ifneq (($or $(filter gcc5,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),)
>  DEVELOPER_CFLAGS += -Wpedantic
> -ifneq ($(filter gcc5,$(COMPILER_FEATURES)),)
> +ifneq ($(filter gcc10,$(COMPILER_FEATURES)),)
> +ifeq ($(uname_S),MINGW)
>  DEVELOPER_CFLAGS += -Wno-pedantic-ms-format
>  endif
>  endif
> +endif
> +endif
>  DEVELOPER_CFLAGS += -Wdeclaration-after-statement
>  DEVELOPER_CFLAGS += -Wformat-security
>  DEVELOPER_CFLAGS += -Wold-style-definition
> diff --git a/config.mak.uname b/config.mak.uname
> index 76516aaa9a..124ddfce36 100644
> --- a/config.mak.uname
> +++ b/config.mak.uname
> @@ -11,6 +11,10 @@ uname_R := $(shell sh -c 'uname -r 2>/dev/null || echo not')
>  uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
>  uname_V := $(shell sh -c 'uname -v 2>/dev/null || echo not')
>  
> +ifneq ($(findstring MINGW,$(uname_S)),)
> +	uname_S := MINGW
> +endif
> +
>  ifdef MSVC
>  	# avoid the MingW and Cygwin configuration sections
>  	uname_S := Windows
> @@ -588,7 +592,7 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
>  	SANE_TOOL_PATH = /usr/coreutils/bin:/usr/local/bin
>  	SHELL_PATH = /usr/coreutils/bin/bash
>  endif
> -ifneq (,$(findstring MINGW,$(uname_S)))
> +ifeq ($(uname_S),MINGW)
>  	pathsep = ;
>  	HAVE_ALLOCA_H = YesPlease
>  	NO_PREAD = YesPlease
> @@ -705,6 +709,8 @@ ifeq ($(uname_S),QNX)
>  	NO_STRLCPY = YesPlease
>  endif
>  
> +export uname_S
> +