Re: [dpdk-dev] [PATCH] eal: fix warnings on Windows

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

On Wed, 13 May 2020 15:53:41 -0700 Pallavi Kadam wrote:
> This patch fixes bunch of warnings when compiling on Windows
> such as the use of an unsafe string function (strerror),
> [-Wunused-const-variable] in getopt.c and
> [-Wunused-variable], [-Wunused-function] in eal_common_options.c
> 
> Signed-off-by: Ranjit Menon <ranjit.menon@intel.com>
> Signed-off-by: Pallavi Kadam <pallavi.kadam@intel.com>
> Tested-by: Pallavi Kadam <pallavi.kadam@intel.com>
> ---
>  lib/librte_eal/common/eal_common_options.c | 6 +++++-
>  lib/librte_eal/windows/getopt.c            | 4 ++--
>  2 files changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_eal/common/eal_common_options.c
> b/lib/librte_eal/common/eal_common_options.c index
> 8f2cbd1c6..2efbf59e4 100644 ---
> a/lib/librte_eal/common/eal_common_options.c +++
> b/lib/librte_eal/common/eal_common_options.c @@ -115,8 +115,10 @@
> struct shared_driver { static struct shared_driver_list solib_list =
>  TAILQ_HEAD_INITIALIZER(solib_list);
>  
> +#ifndef RTE_EXEC_ENV_WINDOWS
>  /* Default path of external loadable drivers */
>  static const char *default_solib_dir = RTE_EAL_PMD_PATH;
> +#endif
>  
>  /*
>   * Stringified version of solib path used by dpdk-pmdinfo.py
> @@ -329,6 +331,7 @@ eal_plugin_add(const char *path)
>  	return 0;
>  }
>  
> +#ifndef RTE_EXEC_ENV_WINDOWS
>  static int
>  eal_plugindir_init(const char *path)
>  {
> @@ -362,6 +365,7 @@ eal_plugindir_init(const char *path)
>  	/* XXX this ignores failures from readdir() itself */
>  	return (dent == NULL) ? 0 : -1;
>  }
> +#endif

This causes different warnings:

In file included from ../../../lib/librte_eal/common/eal_common_options.c:21:
At top level:
../../../lib/librte_eal/windows/include/dirent.h:529:1: warning: 'closedir' defined but not used [-Wunused-function]
  529 | closedir(DIR *dirp)
      | ^~~~~~~~
../../../lib/librte_eal/windows/include/dirent.h:447:1: warning: 'readdir' defined but not used [-Wunused-function]
  447 | readdir(DIR *dirp)
      | ^~~~~~~
../../../lib/librte_eal/windows/include/dirent.h:377:1: warning: 'opendir' defined but not used [-Wunused-function]
  377 | opendir(const char *dirname)
      | ^~~~~~~

Suggesting not to include <dirent.h> to this file on Windows (this
makes dirent.h unused in EAL, but other code will require it later).

>  
>  int
>  eal_plugins_init(void)
> @@ -394,8 +398,8 @@ eal_plugins_init(void)
>  		}
>  
>  	}
> -	return 0;
>  #endif
> +	return 0;
>  }
>  
>  /*
> diff --git a/lib/librte_eal/windows/getopt.c
> b/lib/librte_eal/windows/getopt.c index 170c9b5e0..a08f7c109 100644
> --- a/lib/librte_eal/windows/getopt.c
> +++ b/lib/librte_eal/windows/getopt.c
> @@ -25,8 +25,8 @@ int	opterr = 1;		/* if error
> message should be printed */ int	optind = 1;		/*
> index into parent argv vector */ int	optopt = '?';
> 	/* character checked for validity */ 
> -static void pass(void) {}
> -#define warnx(a, ...) pass()
> +static void pass(const char *a) {(void) a; }
> +#define warnx(a, ...) pass(a)
>  
>  #define PRINT_ERROR	((opterr) && (*options != ':'))
>  

Testing with MinGW-w64 (Ubuntu 19.10, package 6.0.0-3, GCC 9.2.1)
reveals additional warnings. Never mind fixing them in a separate patch
to avoid blocking this one. For the record:

../../../lib/librte_eal/common/eal_common_thread.c:180:25: warning: unused parameter 'attr' [-Wunused-parameter]

../../../lib/librte_eal/windows/eal_lcore.c:30:1: warning: old-style function definition [-Wold-style-definition]
   30 | eal_create_cpu_map()

../../../lib/librte_eal/windows/eal_thread.c:149:29: warning: cast between incompatible function types from '__attribute__((noreturn)) void * (*)(void *)' to 'DWORD (*)(void *)' {aka 'long unsigned int (*)(void * '} [-Wcast-function-type]
  149 |  th = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)eal_thread_loop,

../../../lib/librte_eal/windows/eal.c:144:1: warning: 'optnone' attribute directive ignored [-Wattributes]

../../../lib/librte_eal/common/eal_common_options.c: In function 'eal_adjust_config':
../../../lib/librte_eal/windows/include/sched.h:63:55: warning: 'default_set._bits[1]' may be used uninitialized in this function [-Wmaybe-uninitialized]
   63 |   (dst)->_bits[_i] = (src1)->_bits[_i] & (src2)->_bits[_i]; \

--
Dmitry Kozlyuk