* [AMD64 1/3] fix C99-style declarations
@ 2003-10-25 18:28 Jeff Garzik
2003-10-25 20:27 ` Andi Kleen
0 siblings, 1 reply; 6+ messages in thread
From: Jeff Garzik @ 2003-10-25 18:28 UTC (permalink / raw)
To: ak, linux-kernel
Although the compiler has always supposed C99 style, I feel that until
the kernel as a whole moves to C99 style, such code reduces portability
to other compilers. In particular, I am willing to bet Intel's Yamhill
will eventually be supported by the x86-64 code, and non-gcc compilers
will eventually be used to build this platform.
# --------------------------------------------
# 03/10/25 jgarzik@redhat.com 1.1351
# [AMD64] Fix C99-ish mix of declarations and code.
# --------------------------------------------
diff -Nru a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c
--- a/arch/x86_64/ia32/syscall32.c Sat Oct 25 06:08:19 2003
+++ b/arch/x86_64/ia32/syscall32.c Sat Oct 25 06:08:19 2003
@@ -30,10 +30,12 @@
int map_syscall32(struct mm_struct *mm, unsigned long address)
{
pte_t *pte;
+ pmd_t *pmd;
int err = 0;
+
down_read(&mm->mmap_sem);
spin_lock(&mm->page_table_lock);
- pmd_t *pmd = pmd_alloc(mm, pgd_offset(mm, address), address);
+ pmd = pmd_alloc(mm, pgd_offset(mm, address), address);
if (pmd && (pte = pte_alloc_map(mm, pmd, address)) != NULL) {
if (pte_none(*pte)) {
set_pte(pte,
diff -Nru a/arch/x86_64/kernel/bluesmoke.c b/arch/x86_64/kernel/bluesmoke.c
--- a/arch/x86_64/kernel/bluesmoke.c Sat Oct 25 06:08:19 2003
+++ b/arch/x86_64/kernel/bluesmoke.c Sat Oct 25 06:08:19 2003
@@ -200,11 +200,14 @@
static void check_k8_nb(int header)
{
struct pci_dev *nb;
+ u32 statuslow, statushigh;
+ unsigned short errcode;
+ int i;
+
nb = find_k8_nb();
if (nb == NULL)
return;
- u32 statuslow, statushigh;
pci_read_config_dword(nb, 0x48, &statuslow);
pci_read_config_dword(nb, 0x4c, &statushigh);
if (!(statushigh & (1<<31)))
@@ -215,7 +218,7 @@
printk(KERN_ERR "Northbridge status %08x%08x\n",
statushigh,statuslow);
- unsigned short errcode = statuslow & 0xffff;
+ errcode = statuslow & 0xffff;
switch (errcode >> 8) {
case 0:
printk(KERN_ERR " GART TLB error %s %s\n",
@@ -249,7 +252,6 @@
/* should only print when it was a HyperTransport related error. */
printk(KERN_ERR " link number %x\n", (statushigh >> 4) & 3);
- int i;
for (i = 0; i < 32; i++)
if (highbits[i] && (statushigh & (1<<i)))
printk(KERN_ERR " %s\n", highbits[i]);
diff -Nru a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
--- a/arch/x86_64/kernel/setup.c Sat Oct 25 06:08:19 2003
+++ b/arch/x86_64/kernel/setup.c Sat Oct 25 06:08:19 2003
@@ -332,6 +332,7 @@
void __init setup_arch(char **cmdline_p)
{
unsigned long low_mem_size;
+ unsigned long kernel_end;
ROOT_DEV = old_decode_dev(ORIG_ROOT_DEV);
drive_info = DRIVE_INFO;
@@ -380,7 +381,6 @@
(table_end - table_start) << PAGE_SHIFT);
/* reserve kernel */
- unsigned long kernel_end;
kernel_end = round_up(__pa_symbol(&_end),PAGE_SIZE);
reserve_bootmem_generic(HIGH_MEMORY, kernel_end - HIGH_MEMORY);
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [AMD64 1/3] fix C99-style declarations
2003-10-25 18:28 [AMD64 1/3] fix C99-style declarations Jeff Garzik
@ 2003-10-25 20:27 ` Andi Kleen
2003-10-25 20:47 ` John Levon
0 siblings, 1 reply; 6+ messages in thread
From: Andi Kleen @ 2003-10-25 20:27 UTC (permalink / raw)
To: Jeff Garzik; +Cc: ak, linux-kernel
On Sat, Oct 25, 2003 at 02:28:24PM -0400, Jeff Garzik wrote:
>
> Although the compiler has always supposed C99 style, I feel that until
> the kernel as a whole moves to C99 style, such code reduces portability
> to other compilers. In particular, I am willing to bet Intel's Yamhill
> will eventually be supported by the x86-64 code, and non-gcc compilers
> will eventually be used to build this platform.
The intel compiler supports C99 just fine.
x86-64 always used C99 and there is no x86-64 compiler
around that doesn't support it. I must say I was somewhat pissed off
that someone added that nasty warning to the toplevel Makefile
just to comfort some gcc 2.95 users on i386 ("all world is a i386")
I have enough trouble just to get the essential bug/compilefixes accepted
by Linus, so I see no chance to get such things in currently.
-Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [AMD64 1/3] fix C99-style declarations
2003-10-25 20:27 ` Andi Kleen
@ 2003-10-25 20:47 ` John Levon
2003-10-25 20:56 ` Andi Kleen
0 siblings, 1 reply; 6+ messages in thread
From: John Levon @ 2003-10-25 20:47 UTC (permalink / raw)
To: Andi Kleen; +Cc: Jeff Garzik, linux-kernel
On Sat, Oct 25, 2003 at 10:27:50PM +0200, Andi Kleen wrote:
> x86-64 always used C99 and there is no x86-64 compiler
> around that doesn't support it. I must say I was somewhat pissed off
> that someone added that nasty warning to the toplevel Makefile
> just to comfort some gcc 2.95 users on i386 ("all world is a i386")
Sorry, that is bullshit. The change was entirely designed to prevent
people on such architectures hacking general files where there *do*
exist older compilers, to avoid breakage being introduced without it
being flagged.
This has happened more than once in the tree.
When all the architectures have a minimum gcc requirement that accepts
mixed code and declarations by default, it can be removed ...
regards,
john
--
Khendon's Law:
If the same point is made twice by the same person, the thread is over.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [AMD64 1/3] fix C99-style declarations
2003-10-25 20:47 ` John Levon
@ 2003-10-25 20:56 ` Andi Kleen
2003-10-25 21:03 ` John Levon
2003-10-28 9:20 ` Pavel Machek
0 siblings, 2 replies; 6+ messages in thread
From: Andi Kleen @ 2003-10-25 20:56 UTC (permalink / raw)
To: John Levon; +Cc: Andi Kleen, Jeff Garzik, linux-kernel
On Sat, Oct 25, 2003 at 09:47:17PM +0100, John Levon wrote:
> On Sat, Oct 25, 2003 at 10:27:50PM +0200, Andi Kleen wrote:
>
> > x86-64 always used C99 and there is no x86-64 compiler
> > around that doesn't support it. I must say I was somewhat pissed off
> > that someone added that nasty warning to the toplevel Makefile
> > just to comfort some gcc 2.95 users on i386 ("all world is a i386")
>
> Sorry, that is bullshit. The change was entirely designed to prevent
> people on such architectures hacking general files where there *do*
> exist older compilers, to avoid breakage being introduced without it
> being flagged.
I don't think it makes much difference. People hacking on one architecture
break other architectures all the time for various reasons, e.g.
the implicit includes in different architectures vary widely.
The few people left who use 2.95 will just have to live with
occasional breakage when they insist on using a non standards
compliant compiler.
>
> This has happened more than once in the tree.
>
> When all the architectures have a minimum gcc requirement that accepts
> mixed code and declarations by default, it can be removed ...
Would be my prefered solution. Discourage 2.95.
Sooner or later we have to do that anyways when a bug in 2.95
is found that breaks code (has happened with all gccs so far).
Sooner would be better, as supporting 2.95 seems to be already
a significant mainteance burden.
-Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [AMD64 1/3] fix C99-style declarations
2003-10-25 20:56 ` Andi Kleen
@ 2003-10-25 21:03 ` John Levon
2003-10-28 9:20 ` Pavel Machek
1 sibling, 0 replies; 6+ messages in thread
From: John Levon @ 2003-10-25 21:03 UTC (permalink / raw)
To: Andi Kleen; +Cc: Jeff Garzik, linux-kernel
On Sat, Oct 25, 2003 at 10:56:17PM +0200, Andi Kleen wrote:
> I don't think it makes much difference. People hacking on one architecture
> break other architectures all the time for various reasons, e.g.
> the implicit includes in different architectures vary widely.
An unusual argument ...
> The few people left who use 2.95 will just have to live with
I am a little dubious it's "few people". (especially as gcc 2.96 has the
same problem).
regards,
john
--
Khendon's Law:
If the same point is made twice by the same person, the thread is over.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [AMD64 1/3] fix C99-style declarations
2003-10-25 20:56 ` Andi Kleen
2003-10-25 21:03 ` John Levon
@ 2003-10-28 9:20 ` Pavel Machek
1 sibling, 0 replies; 6+ messages in thread
From: Pavel Machek @ 2003-10-28 9:20 UTC (permalink / raw)
To: Andi Kleen; +Cc: John Levon, Jeff Garzik, linux-kernel
Hi!
> > This has happened more than once in the tree.
> >
> > When all the architectures have a minimum gcc requirement that accepts
> > mixed code and declarations by default, it can be removed ...
>
> Would be my prefered solution. Discourage 2.95.
>
> Sooner or later we have to do that anyways when a bug in 2.95
> is found that breaks code (has happened with all gccs so far).
> Sooner would be better, as supporting 2.95 seems to be already
> a significant mainteance burden.
Well.. except that 2.95 is still two times faster than gcc 3.3 :-(.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
^ permalink raw reply [flat|nested] 6+ messages in thread
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2003-10-25 18:28 [AMD64 1/3] fix C99-style declarations Jeff Garzik
2003-10-25 20:27 ` Andi Kleen
2003-10-25 20:47 ` John Levon
2003-10-25 20:56 ` Andi Kleen
2003-10-25 21:03 ` John Levon
2003-10-28 9:20 ` Pavel Machek
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