warning: cast increases required alignment of target type

[Andrey Zonov]

Hi,

Does anyone know how to correctly fix this warning for
arm/ia64/mips/sparc64?

usr.bin/elf2aout/elf2aout.c: In function 'main':
usr.bin/elf2aout/elf2aout.c:129: warning: cast increases required
alignment of target type

I found this explanation from bde, but still don't understand how to
correctly fix this issue.

------------------------------------------------------------------------
r99799 | bde | 2002-07-11 22:06:09 +0400 (Thu, 11 Jul 2002) | 10 lines

Set NO_WERROR to ignore the following warning which is emitted on
alphas:
    .../elf2aout.c:130: warning: cast increases required alignment of
    target type
The warning is about casting ((char *)e + phoff) to a struct pointer,
where e is aligned but phoff might be garbage, so I think the warning
should be emitted on most machines (even on i386's, alignment checking
might be on) and the correct fix would involve validation phoff before
using it.

Is this fix correct?

Index: usr.bin/elf2aout/elf2aout.c
===================================================================
--- usr.bin/elf2aout/elf2aout.c	(revision 239611)
+++ usr.bin/elf2aout/elf2aout.c	(working copy)
@@ -126,7 +126,7 @@
 	entry = xe64toh(e->e_entry);
 	phoff = xe64toh(e->e_phoff);
 	phnum = xe16toh(e->e_phnum);
-	p = (Elf64_Phdr *)((char *)e + phoff);
+	p = (Elf64_Phdr *)(void *)((char *)e + phoff);
 	bzero(&a, sizeof(a));
 	for (i = 0; i < phnum; i++) {
 		type = xe32toh(p[i].p_type);


-- 
Andrey Zonov

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