[src/trunk]: src/lib/libc/gen - don't compile unreachable code.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aa75bb096614
branches:  trunk
changeset: 778268:aa75bb096614
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Mar 21 02:18:14 2012 +0000

description:
- don't compile unreachable code.
- convert uintmax_t to uintptr_t

diffstat:

 lib/libc/gen/nlist_elf32.c |  47 ++++++++++++++++++++++++++-------------------
 1 files changed, 27 insertions(+), 20 deletions(-)

diffs (122 lines):

diff -r 3f61ac114340 -r aa75bb096614 lib/libc/gen/nlist_elf32.c
--- a/lib/libc/gen/nlist_elf32.c        Wed Mar 21 00:38:34 2012 +0000
+++ b/lib/libc/gen/nlist_elf32.c        Wed Mar 21 02:18:14 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nlist_elf32.c,v 1.34 2012/03/20 16:36:05 matt Exp $ */
+/* $NetBSD: nlist_elf32.c,v 1.35 2012/03/21 02:18:14 christos Exp $ */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou
@@ -36,7 +36,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: nlist_elf32.c,v 1.34 2012/03/20 16:36:05 matt Exp $");
+__RCSID("$NetBSD: nlist_elf32.c,v 1.35 2012/03/21 02:18:14 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 /* If not included by nlist_elf64.c, ELFSIZE won't be defined. */
@@ -76,29 +76,32 @@
 ELFNAMEEND(__fdnlist)(int fd, struct nlist *list)
 {
        struct stat st;
-       struct nlist *p;
-       char *mappedfile, *strtab;
-       size_t mappedsize;
-       Elf_Ehdr *ehdrp, ehdr;
-       Elf_Shdr *shdrp, *symshdrp, *symstrshdrp;
-       Elf_Sym *symp;
-       Elf_Off shdr_off;
-       Elf_Word shdr_size;
+       Elf_Ehdr ehdr;
+#if _LP64 || ELFSIZE == 32
 #if (ELFSIZE == 32)
        Elf32_Half nshdr;
 #elif (ELFSIZE == 64)
        Elf64_Word nshdr;
 #endif
-       size_t i, nsyms;
-       int rv, nent;
+       /* Only support 64+32 mode on LP64; no support for 64 mode on ILP32 */
+       Elf_Ehdr *ehdrp;
+       Elf_Shdr *shdrp, *symshdrp, *symstrshdrp;
+       Elf_Sym *symp;
+       Elf_Off shdr_off;
+       Elf_Word shdr_size;
+       struct nlist *p;
+       char *mappedfile, *strtab;
+       size_t mappedsize, nsyms;
+       int nent;
+#endif
+       int rv;
+       size_t i;
 
        _DIAGASSERT(fd != -1);
        _DIAGASSERT(list != NULL);
 
        rv = -1;
 
-       symshdrp = symstrshdrp = NULL;
-
        /*
         * If we can't fstat() the file, something bad is going on.
         */
@@ -134,7 +137,10 @@
        default:
                BAD;
        }
+#if _LP64 || ELFSIZE == 32
+       symshdrp = symstrshdrp = NULL;
 
+       /* Only support 64+32 mode on LP64; no support for 64 mode on ILP32 */
        if (S_ISCHR(st.st_mode)) {
                const char *nlistname;
                struct ksyms_gsymbol kg;
@@ -155,7 +161,7 @@
                        kg.kg_name = nlistname;
                        kg.kg_sym = &sym;
                        if (ioctl(fd, KIOCGSYMBOL, &kg) == 0) {
-                               p->n_value = sym.st_value;
+                               p->n_value = (uintptr_t)sym.st_value;
                                switch (ELF_ST_TYPE(sym.st_info)) {
                                case STT_NOTYPE:
                                        p->n_type = N_UNDF;
@@ -211,7 +217,7 @@
        if (check(shdr_off, shdr_size) ||
            (sizeof *shdrp != ehdrp->e_shentsize))
                BADUNMAP;
-       shdrp = (Elf_Shdr *)(void *)&mappedfile[shdr_off];
+       shdrp = (void *)&mappedfile[(size_t)shdr_off];
 
        for (i = 0; i < nshdr; i++) {
                if (shdrp[i].sh_type == SHT_SYMTAB) {
@@ -230,9 +236,9 @@
        if (check(symstrshdrp->sh_offset, symstrshdrp->sh_size))
                BADUNMAP;
 
-       symp = (Elf_Sym *)(void *)&mappedfile[symshdrp->sh_offset];
-       nsyms = symshdrp->sh_size / sizeof(*symp);
-       strtab = &mappedfile[symstrshdrp->sh_offset];
+       symp = (void *)&mappedfile[(size_t)symshdrp->sh_offset];
+       nsyms = (size_t)(symshdrp->sh_size / sizeof(*symp));
+       strtab = &mappedfile[(size_t)symstrshdrp->sh_offset];
 
        /*
         * Clean out any left-over information for all valid entries.
@@ -267,7 +273,7 @@
                                /*
                                 * Translate (roughly) from ELF to nlist
                                 */
-                               p->n_value = symp[i].st_value;
+                               p->n_value = (uintptr_t)symp[i].st_value;
                                switch (ELF_ST_TYPE(symp[i].st_info)) {
                                case STT_NOTYPE:
                                        p->n_type = N_UNDF;
@@ -302,6 +308,7 @@
        rv = nent;
 unmap:
        munmap(mappedfile, mappedsize);
+#endif /* _LP64 || ELFSIZE == 32 */
 out:
        return (rv);
 }