my gut feeling is that

gd->jt[XF_foo] = foo;

should happen at the end of the file which defines foo. This would remove the need for external definitions and ifdef mazes. But it would require some sort of jt_init function to be called in each file. This could be done using some linker magic (like module initialization in the kernel, or cli functions in u-boot)...

- Amnon

On 5/9/07, Wolfgang Denk wd@denx.de wrote:

In message 1628E43D99629C46988BE46087A3FBB997B7A9@ep-01.EmbeddedPlanet.local you wrote:

...

[PATCH] Functions added to extern for stand alone programs

...

...

Content-Transfer-Encoding: base64 Content-Description: add_extern_func.patch Content-Disposition: attachment; filename=add_extern_func.patch"

RnJvbSAyMDBhZWNiZjJiM2NlYzA0ZDA5M2RkZGRlMWViNWQxNDA1YmE1ZGVhIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiByb290IDxyb290QHVidW50dS4obm9uZSk+CkRhdGU6IFdlZCwg OSBNYXkgMjAwNyAxMjo1NjozNSAtMDQwMApTdWJqZWN0OiBbUEFUQ0hdIEZ1bmN0aW9ucyBhZGRl

...

Please post plain text.

... +#if defined (CONFIG_4xx) || defined (CONFIG_MPC5xxx) || defined (CONFIG_74xx_7xx) || \

• defined (CONFIG_74x) || defined (CONFIG_75x) || defined (CONFIG_74xx) || \
• defined (CONFIG_MPC8220)|| defined (CONFIG_MPC85xx) || defined (CONFIG_MPC86xx) || \
• defined (CONFIG_MPC83XX)

•   gd->jt[XF_out8] = (void *) out8;
  

•   gd->jt[XF_in8] = (void *) in8;
  

•   gd->jt[XF_in16] = (void *) in16;
  

•   gd->jt[XF_out16] = (void *) out16;
  

•   gd->jt[XF_in32] = (void *) in32;
  

•   gd->jt[XF_out32] = (void *) out32;
  

+#endif +#if (CONFIG_COMMANDS & CFG_CMD_NET)

•   gd->jt[XF_netboot_common] = (void *) netboot_common;
  

+#endif

•   gd->jt[XF_strcmp] = (void *) strcmp;
  

+#if (CONFIG_COMMANDS & CFG_CMD_NAND)

•   gd->jt[XF_do_nand] = (void *) do_nand;
  

+#endif +#if (CONFIG_COMMANDS & CFG_CMD_DATE)

•   gd->jt[XF_rtc_get] = (void *) rtc_get;
  

•   gd->jt[XF_do_date] = (void *) do_date;
  

+#endif #if (CONFIG_COMMANDS & CFG_CMD_I2C) gd->jt[XF_i2c_write] = (void *) i2c_write; gd->jt[XF_i2c_read] = (void *) i2c_read;

•   gd->jt[XF_i2c_probe] = (void *) i2c_probe;
  

#endif /* CFG_CMD_I2C */ +#if (CONFIG_COMMANDS & CFG_CMD_USB)

•   gd->jt[XF_usb_init] = (void *) usb_init;
  

•   gd->jt[XF_usb_stop] = (void *) usb_stop;
  

+#endif +#if !defined(CFG_NO_FLASH)

•   gd->jt[XF_flash_write] = (void *) flash_write;
  

+#endif +#if (CONFIG_COMMANDS & CFG_CMD_FLASH)

•   gd->jt[XF_do_protect] = (void *) do_protect;
  

•   gd->jt[XF_do_flerase] = (void *) do_flerase;
  

+#endif }

This #ifdef maze is too much even for my standards. And that does mean something.

Is there anybody out there with an idea how to avoid that?

Best regards,

Wolfgang Denk

-- DENX Software Engineering GmbH, CEO: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de If something is different, it's either better or worse, and usually both. - Larry Wall

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On 5/10/07, Wolfgang Denk wd@denx.de wrote:

+#if (CONFIG_COMMANDS & CFG_CMD_FLASH)

•   gd->jt[XF_do_protect] = (void *) do_protect;
  

•   gd->jt[XF_do_flerase] = (void *) do_flerase;
  

+#endif }

This #ifdef maze is too much even for my standards. And that does mean something.

Is there anybody out there with an idea how to avoid that?

The cond_syscall() macro in the Linux kernel might be worth stealing. How about something like this?

#define cond_extern(name) asm(".weak\t" #name "\n\t.set\t" #name ", unimpl_extern")

static int unimpl_extern(void) { return -ENOSYS; /* or something more appropriate */ }

cond_extern(do_protect); cond_extern(do_flerase);

Haavard

In message e68c55e80705231251s678d3e59g2db9ed3da3fce830@mail.gmail.com you wrote:

...

#define cond_extern(name) asm(".weak\t" #name "\n\t.set\t" #name ", unimpl_extern")

I do not understand what this does. Does it work?

Yes, it does. See file: gcc.info, node: Function Attributes, section: 5.24 Declaring Attributes of Functions

...

static int unimpl_extern(void) { return -ENOSYS; /* or something more appropriate */ }

How is this different that using the dummy function?

The main difference is that with "normal" functions you must make sure that the dummy function does not get compiled / linked when you implement a real function. "Weak" are simply overwritten if any user provides another (real) function with the same name. No #ifdef mess any more :-)

Best regards,

Wolfgang Denk