[ECOS] Re: lwip socket errors

[William Wagner]

On 18/02/2011 20:41, John Dallaway wrote:
> Hi Will
>
> William Wagner wrote:
>
>> Been looking at getting lwip to set errno when errors occur and am
>> struggling a bit. The problem is in
>> packages\net\lwip_tcpip\current\src\api\sockets.c:152
>>
>> To get it so that errno is set with the macro set_errno you must have
>> ERRNO defined. I have changed the cdl so that this is set. However you
>> then get a compilation error as errno is undefined. Attached is my
>> proposed patch to fix the issue. I realise this is a change to lwip code
>> which is best avoided but I can't see any other way of making it work.
>> Opinions?
> According to the lwIP documentation file doc/sys_arch.txt, the file
> include/arch/cc.h "must either include a system-local<errno.h>  which
> defines the standard *nix error codes, or it should #define
> LWIP_PROVIDE_ERRNO to make lwip/arch.h define the codes which are used
> throughout".
>
> Try including errno.h from the file include/arch/cc.h and let us know if
> it helps...

I have tried the below patch instead and this seems to work. I tried 
just making it include cyg/error/errno.h but was running into compile 
errors where the #define errno (*cyg_error_get_errno_p()) in errno.h was 
meaning that subsequent uses of #include <errno.h> lead to compiler 
errors saying (*cyg_error_get_errno_p()).h could not be found. I'm no 
expert on preprocessor rules but I wonder if that is a compiler bug. 
Either way changing cc.h to include errno.h rather than 
cyg/error/errno.h fixed the issue for me. I have then tried to make it 
cope when your config doesn't have isoinfra.


--- a/packages/net/lwip_tcpip/current/include/arch/cc.h
+++ b/packages/net/lwip_tcpip/current/include/arch/cc.h
@@ -34,7 +34,13 @@
  #define __LWIP_ARCH_CC_H__

  #include<string.h>
+#include<pkgconf/isoinfra.h>           /* Configuration header */
+#ifndef CYGINT_ISO_ERRNO
  #include<cyg/error/codes.h>
+#include<cyg/error/errno.h>
+#else
+#include<errno.h>
+#endif
  #include<cyg/infra/cyg_type.h>

  typedef int sys_prot_t;
@@ -47,6 +53,11 @@ typedef int sys_prot_t;
  #define ETIME           62
  #define ENSRNOTFOUND    163

+// If errno support, define ERRNO used in api/sockets.c
+#ifdef CYGPKG_ERROR_ERRNO
+#define ERRNO
+#endif
+
  // Platform byteorder
  #if (CYG_BYTEORDER == CYG_LSBFIRST)
  #define BYTE_ORDER LITTLE_ENDIAN



> John Dallaway
> eCos maintainer
> http://www.dallaway.org.uk/john
>

-- 
------------------------------------------------------------------------
Will Wagner                                     will_wagner@carallon.com
Development Manager                      Office Tel: +44 (0)20 7371 2032
Carallon Ltd, Studio G20, Shepherds Building, Rockley Rd, London W14 0DA
------------------------------------------------------------------------



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