[RFC] code changes/removal in boot2.c and ufsread.c so clang can compile boot2

[Alexander Best]

On Tue Feb 22 11, Warner Losh wrote:
> On 02/18/2011 18:01, Alexander Best wrote:
> >hi everybody,
> >
> >r218745 triggered quite a discussion about dead code in boot2.c. i talked 
> >to
> >roman (rdivacky@) and we were trying to improve the situation so that boot2
> >would build with clang 2.8 (base) and the latest development version of
> >clang (trunk). a lot of the ideas came from Bruce (bde@).
> >
> >i'd really appreciate, if somebody could have a look at this patchset. for 
> >me
> >it strips down the boot2 code so clang is able to compile it just fine. 
> >please
> >bear in mind that this has to work with boot2 supporting UFS1 *and* UFS2. 
> >so
> >please be sure not to override BOOT2_UFS in your src.conf or some place 
> >else.
> >
> >you should be able to test the (hopefully sucessfully) compiled boot2 
> >binary
> >by copying it to /boot. please be sure to keep a backup of your existing 
> >boot2
> >file in case something breaks.
> >
> >the patchset (against a recent HEAD) can be found here:
> >http://people.freebsd.org/~arundel/patches/boot2.c.diff2
> >
> >cheers.
> >alex
> >
> 
> Here's some comments:
> 
> @@ -88,7 +97,7 @@ static ino_t lookup(const char *);
>  static ssize_t fsread(ino_t, void *, size_t);
> 
>  static int ls, dsk_meta;
> -static uint32_t fs_off;
> +static uint32_t fs_off = 0;
> 
>  static __inline int
>  fsfind(const char *name, ino_t * ino)
> @@ -98,7 +107,6 @@ fsfind(const char *name, ino_t * ino)
>  	char *s;
>  	ssize_t n;
> 
> -	fs_off = 0;
>  	while ((n = fsread(*ino, buf, DEV_BSIZE))>  0)
>  		for (s = buf; s<  buf + DEV_BSIZE;) {
>  			d = (void *)s;
> 
> How does the first part of this diff change things?  bss gets the 
> uninitialized and the data initialized to 0.
> 
> but we also have this later:
> 
> @@ -238,7 +245,6 @@ fsread(ino_t inode, void *buf, size_t nbyte)
> 
>  #endif
>  		inomap = inode;
> -		fs_off = 0;
>  		blkmap = indmap = 0;
>  	}
>  	s = buf;
> 
> 
> -    if (N_GETMAGIC(hdr.ex) == ZMAGIC)
> -	fmt = 0;
> -    else if (IS_ELF(hdr.eh))
> +    if (IS_ELF(eh))
>  	fmt = 1;
> 
> 
> Doesn't this remove a.out support?

indeed i removed that part from the newest patch:

http://people.freebsd.org/~arundel/patches/boot2.c.diff3

> 
> Warner

-- 
a13x