[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a link or even a runtime error.

With -Werror-implicit-function-declaration, we are getting an immediate 
compile error instead.

This patch also removes some unneeded spaces between two tabs in the 
following line.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

This patch was already sent on:
- 30 Jul 2005

--- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
+++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
@@ -351,7 +351,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-	  	   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration \
+		   -fno-strict-aliasing -fno-common \
 		   -ffreestanding
 AFLAGS		:= -D__ASSEMBLY__
 

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Olaf Hering]

 On Tue, Aug 30, Adrian Bunk wrote:

> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a link or even a runtime error.
> 
> With -Werror-implicit-function-declaration, we are getting an immediate 
> compile error instead.

You have to fix CONFIG_SWAP=n as well.

http://lkml.org/lkml/2005/8/6/72

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Tue, Aug 30, 2005 at 06:18:14PM +0200, Olaf Hering wrote:
>  On Tue, Aug 30, Adrian Bunk wrote:
> 
> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a link or even a runtime error.
> > 
> > With -Werror-implicit-function-declaration, we are getting an immediate 
> > compile error instead.
> 
> You have to fix CONFIG_SWAP=n as well.
> 
> http://lkml.org/lkml/2005/8/6/72

I don't see any such warning in the 2.6.13 sparc build at Jan's 
crosscompile page [1], and all my patch does is to turn a warning into 
an error.

If a #define is using it before the header with the prototype get's 
#include'd that's no problem as long as the prototype is available when 
the #define is _used_.

I'm not saying that there aren't cases this patch will break (and my 
patch shouldn't go into 2.6.14), but your example doesn't seem to cause 
problems.

cu
Adrian

[1] http://l4x.org/k/?d=6676

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Olaf Hering]

 On Tue, Aug 30, Adrian Bunk wrote:

> On Tue, Aug 30, 2005 at 06:18:14PM +0200, Olaf Hering wrote:
> >  On Tue, Aug 30, Adrian Bunk wrote:
> > 
> > > Currently, using an undeclared function gives a compile warning, but it 
> > > can lead to a link or even a runtime error.
> > > 
> > > With -Werror-implicit-function-declaration, we are getting an immediate 
> > > compile error instead.
> > 
> > You have to fix CONFIG_SWAP=n as well.
> > 
> > http://lkml.org/lkml/2005/8/6/72
> 
> I don't see any such warning in the 2.6.13 sparc build at Jan's 
> crosscompile page [1], and all my patch does is to turn a warning into 
> an error.

page_cache_release and release_pages will be undefined when compiling
arch/ppc/configs/common_defconfig, but not arch/i386/defconfig, with
CONFIG_SWAP=n

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Tue, Aug 30, 2005 at 06:38:19PM +0200, Olaf Hering wrote:
> 
> page_cache_release and release_pages will be undefined when compiling
> arch/ppc/configs/common_defconfig, but not arch/i386/defconfig, with
> CONFIG_SWAP=n

There will be some compile errors in cases where compilation previously 
worked because the undefined function wasn't called due to gcc dead code 
elimination.

We need to fix some code, but I'd strongly prefer this over the possible 
runtime errors -Werror-implicit-function-declaration prevents in other 
cases.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

RE: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Luck, Tony]

> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build

ia64 allnoconfig is (and has been for a while) broken for other reasons.

Almost all of the real configurations still build.  The only error
that adding this turned up was building a generic uniprocessor config.

smp_call_function_single() is used without a prototype by
arch/ia64/sn/kernel/sn2/sn_hwperf.c:sn_hwperf_op_cpu()

This isn't a real error because this function actually does return
an "int", so the complier default is correct (plus the caller doesn't
look at the return value, plus on a UP we'd never be able to get to
this call-site because it is in the "else" !!!).

But I'll fix it anyway.

diff --git a/include/asm-ia64/smp.h b/include/asm-ia64/smp.h
index 719ff30..949e3a2 100644
--- a/include/asm-ia64/smp.h
+++ b/include/asm-ia64/smp.h
@@ -133,6 +133,7 @@ #else
 
 #define cpu_logical_id(i)		0
 #define cpu_physical_id(i)		ia64_get_lid()
+#define smp_call_function_single(cpuid, func, info, retry, wait) 0
 
 #endif /* CONFIG_SMP */
 #endif /* _ASM_IA64_SMP_H */

-Tony

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a nasty to debug runtime stack corruptions if the prototype 
of the function is different from what gcc guessed.

With -Werror-implicit-function-declaration we are getting an immediate
compile error instead.

Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

 Makefile                               |    3 ++-
 drivers/input/joystick/iforce/Makefile |    2 --
 2 files changed, 2 insertions(+), 3 deletions(-)

--- linux-2.6.17-mm6-full/Makefile.old	2006-07-06 12:17:02.000000000 +0200
+++ linux-2.6.17-mm6-full/Makefile	2006-07-06 12:18:52.000000000 +0200
@@ -318,7 +318,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                   -fno-strict-aliasing -fno-common
+                   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration
 # Force gcc to behave correct even for buggy distributions
 CFLAGS          += $(call cc-option, -fno-stack-protector-all \
                                      -fno-stack-protector)
--- linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile.old	2006-07-06 12:19:08.000000000 +0200
+++ linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile	2006-07-06 12:19:16.000000000 +0200
@@ -16,5 +16,3 @@
 ifeq ($(CONFIG_JOYSTICK_IFORCE_USB),y)
 	iforce-objs += iforce-usb.o
 endif
-
-EXTRA_CFLAGS = -Werror-implicit-function-declaration

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Jesper Juhl]

On 06/07/06, Adrian Bunk <bunk@stusta.de> wrote:
> Currently, using an undeclared function gives a compile warning, but it
> can lead to a nasty to debug runtime stack corruptions if the prototype
> of the function is different from what gcc guessed.
>
> With -Werror-implicit-function-declaration we are getting an immediate
> compile error instead.
>
> Signed-off-by: Adrian Bunk <bunk@stusta.de>
>
Makes good sense. It gets my vote.
Thanks Adrian.

-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Dave Jones]

On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
 > Currently, using an undeclared function gives a compile warning, but it 
 > can lead to a nasty to debug runtime stack corruptions if the prototype 
 > of the function is different from what gcc guessed.
 > 
 > With -Werror-implicit-function-declaration we are getting an immediate
 > compile error instead.
 > 
 > Signed-off-by: Adrian Bunk <bunk@stusta.de>

I've been carrying pretty much the same patch in Fedora for months,
and making sure it still builds across x86/x86-64/s390/ia64/ppc32/ppc64.
It saves a lot of time when you're building a large heavily modular kernel.
(like that from a distro config say)

Signed-off-by: Dave Jones <davej@redhat.com>

-- 
http://www.codemonkey.org.uk

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a nasty to debug runtime stack corruptions if the prototype 
> of the function is different from what gcc guessed.
> 
> With -Werror-implicit-function-declaration we are getting an immediate
> compile error instead.
This patch broke (-rc1):

sparc allnoconfig build
ia64 allnoconfig build
ppc64 allnoconfig build

x86_64 succeded an allnoconfig build

I did not try other architectures. We need to fix the allnoconfig cases
at least for the popular architectures before applying this patch
otherwise it will create too much trouble/noise.

linux-arch copied in the hope that the arch maintaines may try it out
and fix their issues.

	Sam

---

 Makefile                               |    3 ++-
 drivers/input/joystick/iforce/Makefile |    2 --
 2 files changed, 2 insertions(+), 3 deletions(-)

--- linux-2.6.17-mm6-full/Makefile.old	2006-07-06 12:17:02.000000000 +0200
+++ linux-2.6.17-mm6-full/Makefile	2006-07-06 12:18:52.000000000 +0200
@@ -318,7 +318,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                   -fno-strict-aliasing -fno-common
+                   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration
 # Force gcc to behave correct even for buggy distributions
 CFLAGS          += $(call cc-option, -fno-stack-protector-all \
                                      -fno-stack-protector)
--- linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile.old	2006-07-06 12:19:08.000000000 +0200
+++ linux-2.6.17-mm6-full/drivers/input/joystick/iforce/Makefile	2006-07-06 12:19:16.000000000 +0200
@@ -16,5 +16,3 @@
 ifeq ($(CONFIG_JOYSTICK_IFORCE_USB),y)
 	iforce-objs += iforce-usb.o
 endif
-
-EXTRA_CFLAGS = -Werror-implicit-function-declaration

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Valdis.Kletnieks]

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On Fri, 07 Jul 2006 05:36:30 +0200, Sam Ravnborg said:
> On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
...
> I did not try other architectures. We need to fix the allnoconfig cases
> at least for the popular architectures before applying this patch
> otherwise it will create too much trouble/noise.

What source files did it break on, and with what error message?  And is
there a reason to focus on 'allnoconfig', or do the other canned config
targets (allyes, allmod, rand, and so on) matter too?


[-- Attachment #2: Type: application/pgp-signature, Size: 226 bytes --]

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Fri, Jul 07, 2006 at 01:02:18AM -0400, Valdis.Kletnieks@vt.edu wrote:
> On Fri, 07 Jul 2006 05:36:30 +0200, Sam Ravnborg said:
> > On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > > With -Werror-implicit-function-declaration we are getting an immediate
> > > compile error instead.
> > This patch broke (-rc1):
> ...
> > I did not try other architectures. We need to fix the allnoconfig cases
> > at least for the popular architectures before applying this patch
> > otherwise it will create too much trouble/noise.
> 
> What source files did it break on, and with what error message?  And is
> there a reason to focus on 'allnoconfig', or do the other canned config
> targets (allyes, allmod, rand, and so on) matter too?

The other configs matters too - but it just seemed most logical to start
out with the config that deselected the most.
One could say that passing 'allnoconfig' was the minimal test.

The error messages follows (for ia64, sparc and ppc64).
I have not tried to fix any of them.

	Sam

make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oia64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oia64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CC      arch/ia64/kernel/asm-offsets.s
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:11,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
/home/sam/kernel/kbuild.git/include/linux/mm.h: In function `lowmem_page_address':
/home/sam/kernel/kbuild.git/include/linux/mm.h:530: error: implicit declaration of function `page_to_pfn'
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:12,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
include2/asm/uaccess.h: In function `xlate_dev_mem_ptr':
include2/asm/uaccess.h:374: error: implicit declaration of function `pfn_to_page'
include2/asm/uaccess.h:374: warning: assignment makes pointer from integer without a cast
include2/asm/uaccess.h: In function `xlate_dev_kmem_ptr':
include2/asm/uaccess.h:392: warning: assignment makes pointer from integer without a cast
make[3]: *** [arch/ia64/kernel/asm-offsets.s] Error 1
make[2]: *** [prepare0] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2

make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oia64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oia64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CC      arch/ia64/kernel/asm-offsets.s
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:11,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
/home/sam/kernel/kbuild.git/include/linux/mm.h: In function `lowmem_page_address':
/home/sam/kernel/kbuild.git/include/linux/mm.h:530: error: implicit declaration of function `page_to_pfn'
In file included from /home/sam/kernel/kbuild.git/include/linux/poll.h:12,
                 from /home/sam/kernel/kbuild.git/include/linux/rtc.h:113,
                 from /home/sam/kernel/kbuild.git/include/linux/efi.h:19,
                 from include2/asm/sal.h:40,
                 from /home/sam/kernel/kbuild.git/include/asm-ia64/mca.h:20,
                 from /home/sam/kernel/kbuild.git/arch/ia64/kernel/asm-offsets.c:15:
include2/asm/uaccess.h: In function `xlate_dev_mem_ptr':
include2/asm/uaccess.h:374: error: implicit declaration of function `pfn_to_page'
include2/asm/uaccess.h:374: warning: assignment makes pointer from integer without a cast
include2/asm/uaccess.h: In function `xlate_dev_kmem_ptr':
include2/asm/uaccess.h:392: warning: assignment makes pointer from integer without a cast
make[3]: *** [arch/ia64/kernel/asm-offsets.s] Error 1
make[2]: *** [prepare0] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2
make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/osparc
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/osparc/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CHK     include/linux/compile.h
  CC      arch/sparc/mm/init.o
In file included from include2/asm/tlb.h:22,
                 from /home/sam/kernel/kbuild.git/arch/sparc/mm/init.c:32:
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
make[3]: *** [arch/sparc/mm/init.o] Error 1
make[2]: *** [arch/sparc/mm] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2


make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oppc64
  Using /home/sam/kernel/kbuild.git as source for kernel
  GEN     /home/sam/kernel/oppc64/Makefile
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  SYMLINK include/asm -> include/asm-powerpc
  CHK     include/linux/compile.h
  CC      arch/powerpc/mm/tlb_32.o
In file included from include2/asm/tlb.h:52,
                 from /home/sam/kernel/kbuild.git/arch/powerpc/mm/tlb_32.c:31:
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
/home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
make[3]: *** [arch/powerpc/mm/tlb_32.o] Error 1
make[2]: *** [arch/powerpc/mm] Error 2
make[1]: *** [_all] Error 2
make: *** [all] Error 2

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Jul 07, 2006 at 08:42:18AM +0200, Sam Ravnborg wrote:
>...
> make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/osparc
>   Using /home/sam/kernel/kbuild.git as source for kernel
>   GEN     /home/sam/kernel/osparc/Makefile
>   CHK     include/linux/version.h
>   CHK     include/linux/utsrelease.h
>   CHK     include/linux/compile.h
>   CC      arch/sparc/mm/init.o
> In file included from include2/asm/tlb.h:22,
>                  from /home/sam/kernel/kbuild.git/arch/sparc/mm/init.c:32:
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
> make[3]: *** [arch/sparc/mm/init.o] Error 1
> make[2]: *** [arch/sparc/mm] Error 2
> make[1]: *** [_all] Error 2
> make: *** [all] Error 2
>...

OK, I tried starting with this one.

The problem is that in the CONFIG_SWAP=n case, linux/swap.h uses these 
functions.

These implicit declarations are bugs that should be fixed.

I tried adding an #include <linux/pagemap.h> to linux/swap.h, but this 
broke things faster than I could fix them.

Does anyone know our header mess good enough for being able to help me 
with this issue?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Milton Miller]

> On Fri, 07 Jul 2006 05:36:30 +0200, Sam Ravnborg said:
> > On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > > With -Werror-implicit-function-declaration we are getting an immediate
> > > compile error instead.
> > This patch broke (-rc1):
> ...
> > I did not try other architectures. We need to fix the allnoconfig cases
> > at least for the popular architectures before applying this patch
> > otherwise it will create too much trouble/noise.


Sam wrote on Fri Jul 07 2006 - 02:40:55 EST::
> The error messages follows (for ia64, sparc and ppc64).
> make -C /home/sam/kernel/kbuild.git O=/home/sam/kernel/oppc64
> Using /home/sam/kernel/kbuild.git as source for kernel
> GEN /home/sam/kernel/oppc64/Makefile
> CHK include/linux/version.h
> CHK include/linux/utsrelease.h
> SYMLINK include/asm -> include/asm-powerpc
> CHK include/linux/compile.h
> CC arch/powerpc/mm/tlb_32.o
> In file included from include2/asm/tlb.h:52,
> from /home/sam/kernel/kbuild.git/arch/powerpc/mm/tlb_32.c:31:
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_flush_mmu':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages'
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h: In function `tlb_remove_page':
> /home/sam/kernel/kbuild.git/include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release'
> make[3]: *** [arch/powerpc/mm/tlb_32.o] Error 1
> make[2]: *** [arch/powerpc/mm] Error 2
> make[1]: *** [_all] Error 2
> make: *** [all] Error 2
> 


That is cross architcture (asm-generic) CONFIG_SWAP=n

http://marc.theaimsgroup.com/?l=linux-kernel&m=106674447120368&w=2

My vote is if the file needs it in an inline, add the include.   Otherwise
split the definition to a new file..

miton

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Jul 07, 2006 at 05:36:30AM +0200, Sam Ravnborg wrote:
> On Thu, Jul 06, 2006 at 06:37:28PM +0200, Adrian Bunk wrote:
> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > of the function is different from what gcc guessed.
> > 
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build
>...

I did defconfig builds on 12 architectures, but no allnoconfig builds.

I'll try to fix them.

> 	Sam
>...

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Heiko Carstens]

> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > of the function is different from what gcc guessed.
> > 
> > With -Werror-implicit-function-declaration we are getting an immediate
> > compile error instead.
> This patch broke (-rc1):
> 
> sparc allnoconfig build
> ia64 allnoconfig build
> ppc64 allnoconfig build
> 
> x86_64 succeded an allnoconfig build
> 
> I did not try other architectures. We need to fix the allnoconfig cases
> at least for the popular architectures before applying this patch
> otherwise it will create too much trouble/noise.

s390 builds with defconfig and allnoconfig and a few other variants as well.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Fri, Jul 07, 2006 at 09:49:18AM +0200, Heiko Carstens wrote:
> > > Currently, using an undeclared function gives a compile warning, but it 
> > > can lead to a nasty to debug runtime stack corruptions if the prototype 
> > > of the function is different from what gcc guessed.
> > > 
> > > With -Werror-implicit-function-declaration we are getting an immediate
> > > compile error instead.
> > This patch broke (-rc1):
> > 
> > sparc allnoconfig build
> > ia64 allnoconfig build
> > ppc64 allnoconfig build
> > 
> > x86_64 succeded an allnoconfig build
> > 
> > I did not try other architectures. We need to fix the allnoconfig cases
> > at least for the popular architectures before applying this patch
> > otherwise it will create too much trouble/noise.
> 
> s390 builds with defconfig and allnoconfig and a few other variants as well.
Thanks for testing.

	Sam

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a nasty to debug runtime stack corruptions if the prototype 
of the function is different from what gcc guessed.

With -Werror-implicit-function-declaration we are getting an immediate
compile error instead.

Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

 Makefile                               |    3 ++-
 drivers/input/joystick/iforce/Makefile |    2 --
 2 files changed, 2 insertions(+), 3 deletions(-)

--- linux-2.6.17-mm3-full/Makefile.old	2006-06-27 11:06:51.000000000 +0200
+++ linux-2.6.17-mm3-full/Makefile	2006-06-27 11:07:12.000000000 +0200
@@ -317,7 +317,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS          := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                   -fno-strict-aliasing -fno-common
+                   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration
 AFLAGS          := -D__ASSEMBLY__
 
 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
--- linux-2.6.17-mm3-full/drivers/input/joystick/iforce/Makefile.old	2006-06-27 11:07:20.000000000 +0200
+++ linux-2.6.17-mm3-full/drivers/input/joystick/iforce/Makefile	2006-06-27 11:07:32.000000000 +0200
@@ -16,5 +16,3 @@
 ifeq ($(CONFIG_JOYSTICK_IFORCE_USB),y)
 	iforce-objs += iforce-usb.o
 endif
-
-EXTRA_CFLAGS = -Werror-implicit-function-declaration

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a nasty runtime error if the prototype of the function is 
different from what gcc guessed.

With -Werror-implicit-function-declaration, we are getting an immediate 
compile error instead.

There will be some compile errors in cases where compilation previously
worked because the undefined function wasn't called due to gcc dead code
elimination, but in these cases a proper fix doesnt harm.


This patch also removes some unneeded spaces between two tabs in the 
following line and a now no longer required
-Werror-implicit-function-declaration from
drivers/input/joystick/iforce/Makefile.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

--- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
+++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
@@ -351,7 +351,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-	  	   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration \
+		   -fno-strict-aliasing -fno-common \
 		   -ffreestanding
 AFLAGS		:= -D__ASSEMBLY__
 

--- linux-2.6.15-rc2-mm1-full/drivers/input/joystick/iforce/Makefile.old	2005-11-23 14:22:11.000000000 +0100
+++ linux-2.6.15-rc2-mm1-full/drivers/input/joystick/iforce/Makefile	2005-11-23 14:22:17.000000000 +0100
@@ -17,4 +17,3 @@
 	iforce-objs += iforce-usb.o
 endif
 
-EXTRA_CFLAGS = -Werror-implicit-function-declaration

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a nasty runtime error if the prototype of the function is 
> different from what gcc guessed.
> 
> With -Werror-implicit-function-declaration, we are getting an immediate 
> compile error instead.

Where "we" == "me".  This patch means I get to fix all the errors which I
encounter.  No fair.  This should be the last patch, not the first.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Wed, Nov 23, 2005 at 03:09:05PM -0800, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a nasty runtime error if the prototype of the function is 
> > different from what gcc guessed.
> > 
> > With -Werror-implicit-function-declaration, we are getting an immediate 
> > compile error instead.
> 
> Where "we" == "me".  This patch means I get to fix all the errors which I
> encounter.  No fair.  This should be the last patch, not the first.

Is it my fault that you applied neither Al Viro's patches to remove the 
usages of the ISA legacy functions nor my patch to mark 
virt_to_bus/bus_to_virt as __deprecated on i386?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> On Wed, Nov 23, 2005 at 03:09:05PM -0800, Andrew Morton wrote:
> > Adrian Bunk <bunk@stusta.de> wrote:
> > >
> > > Currently, using an undeclared function gives a compile warning, but it 
> > > can lead to a nasty runtime error if the prototype of the function is 
> > > different from what gcc guessed.
> > > 
> > > With -Werror-implicit-function-declaration, we are getting an immediate 
> > > compile error instead.
> > 
> > Where "we" == "me".  This patch means I get to fix all the errors which I
> > encounter.  No fair.  This should be the last patch, not the first.
> 
> Is it my fault that you applied neither Al Viro's patches to remove the 
> usages of the ISA legacy functions

Never saw them.

> nor my patch to mark 
> virt_to_bus/bus_to_virt as __deprecated on i386?

That won't make powerpc compile.

Plus there are various other unfixed functions around the tree with various
.configs.

It took about four releases to teach people that the jsm driver won't
compile.  I don't want to go adding things to -mm which break it in this
way - that causes us to lose testers.

The patch is a good one, but it should come last.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Wed, Nov 23, 2005 at 03:50:35PM -0800, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > On Wed, Nov 23, 2005 at 03:09:05PM -0800, Andrew Morton wrote:
> > > Adrian Bunk <bunk@stusta.de> wrote:
> > > >
> > > > Currently, using an undeclared function gives a compile warning, but it 
> > > > can lead to a nasty runtime error if the prototype of the function is 
> > > > different from what gcc guessed.
> > > > 
> > > > With -Werror-implicit-function-declaration, we are getting an immediate 
> > > > compile error instead.
> > > 
> > > Where "we" == "me".  This patch means I get to fix all the errors which I
> > > encounter.  No fair.  This should be the last patch, not the first.
> > 
> > Is it my fault that you applied neither Al Viro's patches to remove the 
> > usages of the ISA legacy functions
> 
> Never saw them.

It's the patch series starting with
  http://www.ussg.iu.edu/hypermail/linux/kernel/0511.1/2685.html

> > nor my patch to mark 
> > virt_to_bus/bus_to_virt as __deprecated on i386?
> 
> That won't make powerpc compile.

Judging from the feedback when I sent this patch first, there are people 
who might notice and actually fix these issues.

> Plus there are various other unfixed functions around the tree with various
> .configs.

And it's my job to fix every single such bug before you'd accept 
-Werror-implicit-function-declaration in the CFLAGS?

Yes, these are bugs.
And yes, they do already generate warnings.

> It took about four releases to teach people that the jsm driver won't
> compile.  I don't want to go adding things to -mm which break it in this
> way - that causes us to lose testers.

-Werror-implicit-function-declaration helps us to avoid a class of 
hard to find _runtime_ errors.

I'm already sending patches to fix all the warnings with 
-Wmissing-prototypes (which is roughly spoken the other side of the 
implicit-function-declaration issue) at least on i386 before I'm 
proposing to add this flag to the global CFLAGS, and while doing this 
I've already found and fixed three _runtime_ errors.

But judging from your comments you might then reject 
-Wmissing-prototypes because it causes warnings on other 
architectures...

IMHO reducing the number of hard to find runtime errors is more 
important than to get allmodconfig compiling in every -mm 
on all architectures.

> The patch is a good one, but it should come last.

Instead of telling me that I have to fix compile breakages with all 
possible .config's on all architectures before you would accept my 
patch, couldn't you be honest and simply tell me to fuck off?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a nasty runtime error if the prototype of the function is 
different from what gcc guessed.

With -Werror-implicit-function-declaration, we are getting an immediate 
compile error instead.

There will be some compile errors in cases where compilation previously
worked because the undefined function wasn't called due to gcc dead code
elimination, but in these cases a proper fix doesnt harm.


This patch also removes some unneeded spaces between two tabs in the 
following line.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

This patch was already sent on:
- 30 Aug 2005
- 30 Jul 2005

--- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
+++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
@@ -351,7 +351,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-	  	   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration \
+		   -fno-strict-aliasing -fno-common \
 		   -ffreestanding
 AFLAGS		:= -D__ASSEMBLY__
 

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> Currently, using an undeclared function gives a compile warning, but it 
>  can lead to a nasty runtime error if the prototype of the function is 
>  different from what gcc guessed.
> 
>  With -Werror-implicit-function-declaration, we are getting an immediate 
>  compile error instead.
> 
>  There will be some compile errors in cases where compilation previously
>  worked because the undefined function wasn't called due to gcc dead code
>  elimination, but in these cases a proper fix doesnt harm.
> 

Sorry, I need to build allmodconfig kernels on wacky architectures (eg
ppc64) and this patch is killing me.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Thu, Nov 10, 2005 at 04:28:57AM -0800, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > Currently, using an undeclared function gives a compile warning, but it 
> >  can lead to a nasty runtime error if the prototype of the function is 
> >  different from what gcc guessed.
> > 
> >  With -Werror-implicit-function-declaration, we are getting an immediate 
> >  compile error instead.
> > 
> >  There will be some compile errors in cases where compilation previously
> >  worked because the undefined function wasn't called due to gcc dead code
> >  elimination, but in these cases a proper fix doesnt harm.
> > 
> 
> Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> ppc64) and this patch is killing me.

Can you send me the list of compile errors so that I can work on fixing 
them?

TIA
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> On Thu, Nov 10, 2005 at 04:28:57AM -0800, Andrew Morton wrote:
> > Adrian Bunk <bunk@stusta.de> wrote:
> > >
> > > Currently, using an undeclared function gives a compile warning, but it 
> > >  can lead to a nasty runtime error if the prototype of the function is 
> > >  different from what gcc guessed.
> > > 
> > >  With -Werror-implicit-function-declaration, we are getting an immediate 
> > >  compile error instead.
> > > 
> > >  There will be some compile errors in cases where compilation previously
> > >  worked because the undefined function wasn't called due to gcc dead code
> > >  elimination, but in these cases a proper fix doesnt harm.
> > > 
> > 
> > Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> > ppc64) and this patch is killing me.
> 
> Can you send me the list of compile errors so that I can work on fixing 
> them?
> 

No handily, sorry.   Missing virt_to_bus() is the typical problem.

The cross-tools at http://developer.osdl.org/dev/plm/cross_compile/ are
quite simple to install.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Randy.Dunlap]

On Thu, 10 Nov 2005 18:24:43 -0800 Andrew Morton wrote:

> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > On Thu, Nov 10, 2005 at 04:28:57AM -0800, Andrew Morton wrote:
> > > Adrian Bunk <bunk@stusta.de> wrote:
> > > >
> > > > Currently, using an undeclared function gives a compile warning, but it 
> > > >  can lead to a nasty runtime error if the prototype of the function is 
> > > >  different from what gcc guessed.
> > > > 
> > > >  With -Werror-implicit-function-declaration, we are getting an immediate 
> > > >  compile error instead.
> > > > 
> > > >  There will be some compile errors in cases where compilation previously
> > > >  worked because the undefined function wasn't called due to gcc dead code
> > > >  elimination, but in these cases a proper fix doesnt harm.
> > > > 
> > > 
> > > Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> > > ppc64) and this patch is killing me.
> > 
> > Can you send me the list of compile errors so that I can work on fixing 
> > them?
> > 
> 
> No handily, sorry.   Missing virt_to_bus() is the typical problem.
> 
> The cross-tools at http://developer.osdl.org/dev/plm/cross_compile/ are
> quite simple to install.

Ack that.  Those are the ones I use.

---
~Randy

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Thu, Nov 10, 2005 at 06:24:43PM -0800, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > On Thu, Nov 10, 2005 at 04:28:57AM -0800, Andrew Morton wrote:
> > > Adrian Bunk <bunk@stusta.de> wrote:
> > > >
> > > > Currently, using an undeclared function gives a compile warning, but it 
> > > >  can lead to a nasty runtime error if the prototype of the function is 
> > > >  different from what gcc guessed.
> > > > 
> > > >  With -Werror-implicit-function-declaration, we are getting an immediate 
> > > >  compile error instead.
> > > > 
> > > >  There will be some compile errors in cases where compilation previously
> > > >  worked because the undefined function wasn't called due to gcc dead code
> > > >  elimination, but in these cases a proper fix doesnt harm.
> > > > 
> > > 
> > > Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> > > ppc64) and this patch is killing me.
> > 
> > Can you send me the list of compile errors so that I can work on fixing 
> > them?
> > 
> 
> No handily, sorry.   Missing virt_to_bus() is the typical problem.
>

But in this case -Werror-implicit-function-declaration doesn't create 
new compile errors, it only moves compile errors from compile time to 
link or depmod time - which is IMHO not a bad change.

If you really want to keep the status quo, you can still steal the 
following from sparc64:
  extern unsigned long virt_to_bus_not_defined_use_pci_map(volatile void *addr);
  #define virt_to_bus virt_to_bus_not_defined_use_pci_map
  extern unsigned long bus_to_virt_not_defined_use_pci_map(volatile void *addr);
  #define bus_to_virt bus_to_virt_not_defined_use_pci_map

Would a patch to mark the ISA legacy functions as __deprecated be OK?

This might give some motivation for people to convert drivers and would 
avoid new code like the recently introduced kexec to use this obsolete 
API.

> The cross-tools at http://developer.osdl.org/dev/plm/cross_compile/ are
> quite simple to install.

Thanks, I've tried it.

Other problems I found until I gave up on compiling:
- a problem in sk98lin indirectly corrected by my SkPciWriteCfgDWord() 
  patch
- drivers/net/wireless/tiacx/: missing #include <linux/vmalloc.h>'s
  (see my patch) - this seems to be a real bug

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Nov 11, 2005 at 09:18:49PM +0100, Adrian Bunk wrote:
>...
> But in this case -Werror-implicit-function-declaration doesn't create 
> new compile errors, it only moves compile errors from compile time to 
> link or depmod time - which is IMHO not a bad change.
> 
> If you really want to keep the status quo, you can still steal the 
> following from sparc64:
>   extern unsigned long virt_to_bus_not_defined_use_pci_map(volatile void *addr);
>   #define virt_to_bus virt_to_bus_not_defined_use_pci_map
>   extern unsigned long bus_to_virt_not_defined_use_pci_map(volatile void *addr);
>   #define bus_to_virt bus_to_virt_not_defined_use_pci_map
> 
> Would a patch to mark the ISA legacy functions as __deprecated be OK?
>...

Sorry, this were two separate thoughts:

Would a patch to mark both virt_to_bus/bus_to_virt and the ISA legacy 
functions (that cause similar problems) as __deprecated be OK?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Nov 11, 2005 at 09:20:05PM +0100, Adrian Bunk wrote:
> On Fri, Nov 11, 2005 at 09:18:49PM +0100, Adrian Bunk wrote:
> >...
> > But in this case -Werror-implicit-function-declaration doesn't create 
> > new compile errors, it only moves compile errors from compile time to 
> > link or depmod time - which is IMHO not a bad change.
> > 
> > If you really want to keep the status quo, you can still steal the 
> > following from sparc64:
> >   extern unsigned long virt_to_bus_not_defined_use_pci_map(volatile void *addr);
> >   #define virt_to_bus virt_to_bus_not_defined_use_pci_map
> >   extern unsigned long bus_to_virt_not_defined_use_pci_map(volatile void *addr);
> >   #define bus_to_virt bus_to_virt_not_defined_use_pci_map
> > 
> > Would a patch to mark the ISA legacy functions as __deprecated be OK?
> >...
> 
> Sorry, this were two separate thoughts:
> 
> Would a patch to mark both virt_to_bus/bus_to_virt and the ISA legacy 
> functions (that cause similar problems) as __deprecated be OK?

Rethinking about this:
The ISA legacy functions were declared obsolete five years ago.
Since there are not many drivers using them, we could simply mark the 
drivers still using them as BROKEN.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> > > > 
> > > > Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> > > > ppc64) and this patch is killing me.
> > > 
> > > Can you send me the list of compile errors so that I can work on fixing 
> > > them?
> > > 
> > 
> > No handily, sorry.   Missing virt_to_bus() is the typical problem.
> >
> 
> But in this case -Werror-implicit-function-declaration doesn't create 
> new compile errors, it only moves compile errors from compile time to 
> link or depmod time - which is IMHO not a bad change.

It is a quite inconvenient change if you want to get full coverage with
`make allmodconfig'.

Maybe one can do `make -i' and then weed through the noise - I haven't
tried.

> If you really want to keep the status quo, you can still steal the 
> following from sparc64:
>   extern unsigned long virt_to_bus_not_defined_use_pci_map(volatile void *addr);
>   #define virt_to_bus virt_to_bus_not_defined_use_pci_map
>   extern unsigned long bus_to_virt_not_defined_use_pci_map(volatile void *addr);
>   #define bus_to_virt bus_to_virt_not_defined_use_pci_map

Maybe.  There were some other failures.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Fri, Nov 11, 2005 at 01:24:43PM -0800, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > > > > 
> > > > > Sorry, I need to build allmodconfig kernels on wacky architectures (eg
> > > > > ppc64) and this patch is killing me.
> > > > 
> > > > Can you send me the list of compile errors so that I can work on fixing 
> > > > them?
> > > > 
> > > 
> > > No handily, sorry.   Missing virt_to_bus() is the typical problem.
> > >
> > 
> > But in this case -Werror-implicit-function-declaration doesn't create 
> > new compile errors, it only moves compile errors from compile time to 
> > link or depmod time - which is IMHO not a bad change.
> 
> It is a quite inconvenient change if you want to get full coverage with
> `make allmodconfig'.

It could be a Kconfig item if enabled or not.
Then you could use the new mechanishm in kconfig to disable it for your
allmodconfig builds.

cat allmod.config
CONFIG_CC_ERROR_IMPLICIT_FUNCTION_DECLARATION = 0


That should do the trick, but maybe too inconvinient??

	Sam

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Fri, Nov 11, 2005 at 09:18:49PM +0100, Adrian Bunk wrote:
>...
> This might give some motivation for people to convert drivers and would 
> avoid new code like the recently introduced kexec to use this obsolete 
> API.
>...

/me sits too long in front of the computer

s/kexec//

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

[2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

Currently, using an undeclared function gives a compile warning, but it 
can lead to a link or even a runtime error.

With -Werror-implicit-function-declaration, we are getting an immediate 
compile error instead.

This patch also removes some unneeded spaces between two tabs in the 
following line.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

--- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
+++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
@@ -351,7 +351,8 @@
 CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
 
 CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-	  	   -fno-strict-aliasing -fno-common \
+		   -Werror-implicit-function-declaration \
+		   -fno-strict-aliasing -fno-common \
 		   -ffreestanding
 AFLAGS		:= -D__ASSEMBLY__
 

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Andrew Morton]

Adrian Bunk <bunk@stusta.de> wrote:
>
> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a link or even a runtime error.
> 
> With -Werror-implicit-function-declaration, we are getting an immediate 
> compile error instead.
> 
> This patch also removes some unneeded spaces between two tabs in the 
> following line.
> 
> 
> Signed-off-by: Adrian Bunk <bunk@stusta.de>
> 
> --- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
> +++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
> @@ -351,7 +351,8 @@
>  CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
>  
>  CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
> -	  	   -fno-strict-aliasing -fno-common \
> +		   -Werror-implicit-function-declaration \
> +		   -fno-strict-aliasing -fno-common \
>  		   -ffreestanding
>  AFLAGS		:= -D__ASSEMBLY__
>  

heh.  Nice idea, but if I merge this I'll have tons of monkey work to do
to get ppc64, ia64 and others compiling :(

umm, so what to do?  I'm inclined to just slam it in post-2.6.13 then take
a week off or something.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Adrian Bunk]

On Sat, Jul 30, 2005 at 11:08:00AM -0700, Andrew Morton wrote:
> Adrian Bunk <bunk@stusta.de> wrote:
> >
> > Currently, using an undeclared function gives a compile warning, but it 
> > can lead to a link or even a runtime error.
> > 
> > With -Werror-implicit-function-declaration, we are getting an immediate 
> > compile error instead.
> > 
> > This patch also removes some unneeded spaces between two tabs in the 
> > following line.
> > 
> > 
> > Signed-off-by: Adrian Bunk <bunk@stusta.de>
> > 
> > --- linux-2.6.13-rc3-mm3-full/Makefile.old	2005-07-30 13:55:32.000000000 +0200
> > +++ linux-2.6.13-rc3-mm3-full/Makefile	2005-07-30 13:55:56.000000000 +0200
> > @@ -351,7 +351,8 @@
> >  CPPFLAGS        := -D__KERNEL__ $(LINUXINCLUDE)
> >  
> >  CFLAGS 		:= -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
> > -	  	   -fno-strict-aliasing -fno-common \
> > +		   -Werror-implicit-function-declaration \
> > +		   -fno-strict-aliasing -fno-common \
> >  		   -ffreestanding
> >  AFLAGS		:= -D__ASSEMBLY__
> >  
> 
> heh.  Nice idea, but if I merge this I'll have tons of monkey work to do
> to get ppc64, ia64 and others compiling :(

Looking at Jan's defconfig builds [1], I don't see this.

> umm, so what to do?  I'm inclined to just slam it in post-2.6.13 then take
> a week off or something.



cu
Adrian

[1] http://l4x.org/k/

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Sat, Jul 30, 2005 at 06:52:02PM +0200, Adrian Bunk wrote:
> Currently, using an undeclared function gives a compile warning, but it 
> can lead to a link or even a runtime error.
> 
> With -Werror-implicit-function-declaration, we are getting an immediate 
> compile error instead.
For i386 this is pretty OK.
But what about other architectures?

Before applying this change I want to know the result on a few archs,
and anyway using a CONFIG option may be a safer choice for a while.

> 
> This patch also removes some unneeded spaces between two tabs in the 
> following line.
Please - use tabs for indention, not for alignment.
The below would look rather messy with tabs=4.
Almost everywhere tabs are used in Makefiles it is plina wrong.
Tabs are brillient for indention but you cannot just assume 8 spaces = a
tab. Not even at the beginning of the line.

If you have a nested if or something tabs are there to be used.

	Sam

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Christoph Hellwig]

On Sat, Jul 30, 2005 at 08:52:26PM +0200, Sam Ravnborg wrote:
> Please - use tabs for indention, not for alignment.
> The below would look rather messy with tabs=4.
> Almost everywhere tabs are used in Makefiles it is plina wrong.
> Tabs are brillient for indention but you cannot just assume 8 spaces = a
> tab. Not even at the beginning of the line.

as far as working on the kernel, yes you can assume that.

Re: [2.6 patch] add -Werror-implicit-function-declaration to CFLAGS

[Sam Ravnborg]

On Sat, Jul 30, 2005 at 07:59:11PM +0100, Christoph Hellwig wrote:
> On Sat, Jul 30, 2005 at 08:52:26PM +0200, Sam Ravnborg wrote:
> > Please - use tabs for indention, not for alignment.
> > The below would look rather messy with tabs=4.
> > Almost everywhere tabs are used in Makefiles it is plina wrong.
> > Tabs are brillient for indention but you cannot just assume 8 spaces = a
> > tab. Not even at the beginning of the line.
> 
> as far as working on the kernel, yes you can assume that.

A bad assumption in several cases.
But if one never ever never use tabs != 8 they do not see the horror,
and so they probarly do not care.

For the Makefiles you will continue to see spaces used for alignmnet.

PS. Last word on this issue - I do not wan't to spend my linux time on a
sapce / versus tabs flamefest.

	Sam