Building on Windows with mingw

[Miklos Marton]

Hello all,

I have tried to build the flashrom with mingw on Windows, but the build 
process fails with:

flash.h:336:1: error: '__MINGW_PRINTF_FORMAT' is an unrecognized format 
function
  type [-Werror=format=]
  __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));

I have checked the stdio.h shipped with the mingw installation, but it 
does not contains the __MINGW_PRINTF_FORMAT macro.

I have used the latest available mingw-get-setup, because the 20110530 
version (which mentioned in the wiki as known t obe working) segfaults 
when I select the MSYS Basic System feature.

I can build with WARNERROR=no, but some more permanent fix 
recommentation would be warmly welcome!

[Antonio Ospite]

On Fri, 19 Jan 2018 00:38:53 +0100
Miklos Marton  wrote:
> Hello all,
>
> I have tried to build the flashrom with mingw on Windows, but the build 
> process fails with:
>
> flash.h:336:1: error: '__MINGW_PRINTF_FORMAT' is an unrecognized format 
> function
>   type [-Werror=format=]
>   __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
>
> I have checked the stdio.h shipped with the mingw installation, but it 
> does not contains the __MINGW_PRINTF_FORMAT macro.

Hi,

I have been reading about the printf format on MinGW for another
project and I run into this message.

Miklos are you still experiencing the problem?

Here on Linux with mingw-w64 version 5.0.3 the constant is here in
/usr/share/mingw-w64/include/stdio.h
> I have used the latest available mingw-get-setup, because the 20110530 
> version (which mentioned in the wiki as known t obe working) segfaults 
> when I select the MSYS Basic System feature.
>
> I can build with WARNERROR=no, but some more permanent fix 
> recommentation would be warmly welcome!

I think a change like the following can help:

diff --git a/flash.h b/flash.h
index a80a9c2..4ae5808 100644
--- a/flash.h
+++ b/flash.h
@@ -359,7 +359,7 @@ void start_logging(void);
 int flashrom_print_cb(enum flashrom_log_level level, const char *fmt, va_list ap);
 /* Let gcc and clang check for correct printf-style format strings. */
 int print(enum flashrom_log_level level, const char *fmt, ...)
-#ifdef __MINGW32__
+#ifdef __MINGW_PRINTF_FORMAT
 __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
 #else
 __attribute__((format(printf, 2, 3)));

In case the constant is not defined the compiler may still give warnings
but at least the code will compile.

If the change looks good I can forward it through the proper channels.
BTW are patches sent via git-send-email accepted?

Ciao,
   Antonio

[Márton Miklós]

> Hi,
>
> I have been reading about the printf format on MinGW for another
> project and I run into this message.
>
> Miklos are you still experiencing the problem?
>
> Here on Linux with mingw-w64 version 5.0.3 the constant is here in
> /usr/share/mingw-w64/include/stdio.h
> > I have used the latest available mingw-get-setup, because the 20110530
> > version (which mentioned in the wiki as known t obe working) segfaults
> > when I select the MSYS Basic System feature.
> >
> > I can build with WARNERROR=no, but some more permanent fix
> > recommentation would be warmly welcome!
>
> I think a change like the following can help:
>
> diff --git a/flash.h b/flash.h
> index a80a9c2..4ae5808 100644
> --- a/flash.h
> +++ b/flash.h
> @@ -359,7 +359,7 @@ void start_logging(void);
>   int flashrom_print_cb(enum flashrom_log_level level, const char *fmt, va_list ap);
>   /* Let gcc and clang check for correct printf-style format strings. */
>   int print(enum flashrom_log_level level, const char *fmt, ...)
> -#ifdef __MINGW32__
> +#ifdef __MINGW_PRINTF_FORMAT
>   __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
>   #else
>   __attribute__((format(printf, 2, 3)));
>
> In case the constant is not defined the compiler may still give warnings
> but at least the code will compile.
>
> If the change looks good I can forward it through the proper channels.
> BTW are patches sent via git-send-email accepted?
>
> Ciao,
>     Antonio

Hey Antonio,

Thank you very much for your email, it solves one part of the problem on 
Windows.
Now I got the following warnings:

dummyflasher.c: In function 'dummy_init':
dummyflasher.c:379:12: warning: unknown conversion type character 'j' in 
format [-Wformat=]
    msg_pdbg("Found persistent image %s, %jd B ",
             ^
flash.h:350:49: note: in definition of macro 'msg_pdbg'
  #define msg_pdbg(...) print(FLASHROM_MSG_DEBUG, __VA_ARGS__) /* 
programmer debug */
                                                  ^~~~~~~~~~~
dummyflasher.c:379:12: warning: too many arguments for format 
[-Wformat-extra-args]
    msg_pdbg("Found persistent image %s, %jd B ",
             ^

Best regards,
Miklos Marton

[Antonio Ospite]

On Tue, 27 Feb 2018 20:12:20 +0100
Márton Miklós  wrote:

[...]
> Hey Antonio,
>
> Thank you very much for your email, it solves one part of the problem on 
> Windows.
> Now I got the following warnings:
>
> dummyflasher.c: In function 'dummy_init':
> dummyflasher.c:379:12: warning: unknown conversion type character 'j' in 
> format [-Wformat=]
>     msg_pdbg("Found persistent image %s, %jd B ",
>              ^
> flash.h:350:49: note: in definition of macro 'msg_pdbg'
>   #define msg_pdbg(...) print(FLASHROM_MSG_DEBUG, __VA_ARGS__) /* 
> programmer debug */
>                                                   ^~~~~~~~~~~
> dummyflasher.c:379:12: warning: too many arguments for format 
> [-Wformat-extra-args]
>     msg_pdbg("Found persistent image %s, %jd B ",
>              ^

This is one of the possible warnings I was talking about, and it
derives from the very fact that __MINGW_PRINTF_FORMAT is not defined in
your installation, and the default "printf" format is not enough.

The proper solution would be to get a MinGW version which defines
__MINGW_PRINTF_FORMAT, I see that it has been added "only" in 2012 :)
https://sourceforge.net/p/mingw-w64/mingw-w64/ci/77bc5d6103b5fb9f59fbddab158...

Anyways, one possible workaround to support older MinGW versions would
be to use "gnu_printf" directly as a printf format, like this:

diff --git a/flash.h b/flash.h
index a80a9c2..40a7f1a 100644
--- a/flash.h
+++ b/flash.h
@@ -360,6 +360,9 @@ int flashrom_print_cb(enum flashrom_log_level level, const char *fmt, va_list ap
 /* Let gcc and clang check for correct printf-style format strings. */
 int print(enum flashrom_log_level level, const char *fmt, ...)
 #ifdef __MINGW32__
+#  ifndef __MINGW_PRINTF_FORMAT
+#    define __MINGW_PRINTF_FORMAT gnu_printf
+#  endif
 __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
 #else
 __attribute__((format(printf, 2, 3)));

This should be OK because the define is only applied when using MinGW.

JFYI I decided for a less backward compatible solution in the other
project:
https://git.ao2.it/libam7xxx.git/commitdiff/bbebd199987581ee6f344c89bfb02237...

Ciao,
   Antonio

[Miklos Marton]

> diff --git a/flash.h b/flash.h
> index a80a9c2..40a7f1a 100644
> --- a/flash.h
> +++ b/flash.h
> @@ -360,6 +360,9 @@ int flashrom_print_cb(enum flashrom_log_level level, const char *fmt, va_list ap
>   /* Let gcc and clang check for correct printf-style format strings. */
>   int print(enum flashrom_log_level level, const char *fmt, ...)
>   #ifdef __MINGW32__
> +#  ifndef __MINGW_PRINTF_FORMAT
> +#    define __MINGW_PRINTF_FORMAT gnu_printf
> +#  endif
>   __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
>   #else
>   __attribute__((format(printf, 2, 3)));
>
> This should be OK because the define is only applied when using MinGW.
>
> JFYI I decided for a less backward compatible solution in the other
> project:
> https://git.ao2.it/libam7xxx.git/commitdiff/bbebd199987581ee6f344c89bfb02237...
>
> Ciao,
>     Antonio

This method compiles without warnings. Thank you very much!
Are you planning to submit a patch to flashrom, or should we handle that?

Best regards,
Miklos Marton

[Antonio Ospite]

On Wed, 28 Feb 2018 20:31:13 +0100
Miklos Marton  wrote:
> > diff --git a/flash.h b/flash.h
> > index a80a9c2..40a7f1a 100644
> > --- a/flash.h
> > +++ b/flash.h
> > @@ -360,6 +360,9 @@ int flashrom_print_cb(enum flashrom_log_level level, const char *fmt, va_list ap
> >   /* Let gcc and clang check for correct printf-style format strings. */
> >   int print(enum flashrom_log_level level, const char *fmt, ...)
> >   #ifdef __MINGW32__
> > +#  ifndef __MINGW_PRINTF_FORMAT
> > +#    define __MINGW_PRINTF_FORMAT gnu_printf
> > +#  endif
> >   __attribute__((format(__MINGW_PRINTF_FORMAT, 2, 3)));
> >   #else
> >   __attribute__((format(printf, 2, 3)));
> >
> > This should be OK because the define is only applied when using MinGW.

[...]
> This method compiles without warnings. Thank you very much!
> Are you planning to submit a patch to flashrom, or should we handle that?

I can do it during the week-end.

Ciao,
   Antonio