freebsd-skq/usr.bin/gensetdefs/gensetdefs.c
Peter Wemm dbd049cf6c gensetdefs is a standalone version of the tool that we use to wrap a
struct linker_set around the contents of ELF linker sets.  This tool
also generates setdef0.c and setdef1.c for the alpha and i386 rather than
having these duplicated all over the tree too.

This is required for building KLD modules.
1998-10-14 03:41:01 +00:00

369 lines
8.7 KiB
C

/*-
* Copyright (c) 1997 John D. Polstra.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id$
*/
#include <sys/types.h>
#include <elf.h>
#include <err.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define HASHSIZE 1009u /* Number of hash chains. */
#define PREFIX ".set." /* Section name prefix for linker sets. */
/* One entry in the hash table. */
typedef struct hashent {
struct hashent *next; /* Next entry with the same hash. */
char *name; /* Name of the linker set. */
size_t size; /* Size in bytes. */
} hashent;
/* Allocate storage for "count" objects of type "type". */
#define NEW(type, count) ((type *) xmalloc((count) * sizeof(type)))
static hashent *hashtab[HASHSIZE]; /* Hash chain heads. */
static void enter(const char *, size_t);
static int enter_sets(const char *);
static unsigned int hash(const char *);
static hashent *merge(void);
static int my_byte_order(void);
static void *xmalloc(size_t);
static char *xstrdup(const char *);
/*
* This is a special-purpose program to generate the linker set definitions
* needed when building an ELF kernel. Its arguments are the names of
* ELF object files. It scans the section names of the object files,
* building a table of those that begin with ".set.", which represent
* linker sets. Finally, for each set "foo" with "count" elements, it
* writes a line "DEFINE_SET(foo, count);" to the standard output.
*/
int
main(int argc, char **argv)
{
int i;
int status = EXIT_SUCCESS;
hashent *list;
FILE *fp;
char *ptrop;
int align;
int ch;
for (i = 1; i < argc; i++)
if (enter_sets(argv[i]) == -1)
status = EXIT_FAILURE;
fp = fopen("setdefs.h", "w");
if (!fp)
err(1, "setdefs.h");
list = merge();
while (list != NULL) {
hashent *next;
fprintf(fp, "DEFINE_SET(%s, %lu);\n", list->name,
(unsigned long) (list->size / sizeof (void *)));
next = list->next;
free(list->name);
free(list);
list = next;
}
fclose(fp);
#ifdef __i386__
ptrop = "long";
align = 2;
#endif
#ifdef __alpha__
ptrop = "quad";
align = 3;
#endif
if (!ptrop)
errx(1, "unknown architecture");
fp = fopen("setdef0.c", "w");
if (!fp)
err(1, "setdef0.c");
fprintf(fp, "/* THIS FILE IS GENERATED, DO NOT EDIT. */\n\n");
fprintf(fp, "\
#define DEFINE_SET(set, count) \\\n\
__asm__(\".section .set.\" #set \",\\\"aw\\\"\"); \\\n\
__asm__(\".globl \" #set); \\\n\
__asm__(\".type \" #set \",@object\"); \\\n\
__asm__(\".p2align %d\"); \\\n\
__asm__(#set \":\"); \\\n\
__asm__(\".%s \" #count); \\\n\
__asm__(\".previous\")\n\
#include \"setdefs.h\" /* Contains a `DEFINE_SET' for each set */\n\
", align, ptrop);
fclose(fp);
fp = fopen("setdef1.c", "w");
if (!fp)
err(1, "setdef0.c");
fprintf(fp, "/* THIS FILE IS GENERATED, DO NOT EDIT. */\n\n");
fprintf(fp, "\
#define DEFINE_SET(set, count) \\\n\
__asm__(\".section .set.\" #set \",\\\"aw\\\"\"); \\\n\
__asm__(\".%s 0\"); \\\n\
__asm__(\".previous\")\n\
#include \"setdefs.h\" /* Contains a `DEFINE_SET' for each set */\n\
", ptrop);
fclose(fp);
return (status);
}
/*
* Enter the given string into the hash table, if it is not already there.
* Each hash chain is kept sorted, so that it will be easy to merge the
* chains to get a single sorted list.
*/
static void
enter(const char *name, size_t size)
{
int c = 0;
hashent *entp;
hashent **linkp;
hashent *newp;
linkp = &hashtab[hash(name) % HASHSIZE];
while ((entp = *linkp) != NULL && (c = strcmp(name, entp->name)) > 0)
linkp = &entp->next;
if (entp == NULL || c != 0) { /* Not found; create a new entry. */
newp = NEW(hashent, 1);
newp->name = xstrdup(name);
newp->size = 0;
newp->next = entp;
*linkp = newp;
entp = newp;
}
entp->size += size;
}
/*
* Return a hash value for the given string.
*/
static unsigned int
hash(const char *s)
{
unsigned char ch;
unsigned int h = 0;
while((ch = *s) != '\0') {
h = 9*h + ch;
s++;
}
return (h);
}
/*
* Enter the linker sets from the given ELF object file. Returns 0 on
* success, or -1 if an error occurred.
*/
static int
enter_sets(const char *filename)
{
int i;
FILE *iop;
Elf_Shdr *shdr;
char *shstr;
Elf_Ehdr ehdr;
if ((iop = fopen(filename, "rb")) == NULL) {
warn("%s", filename);
return (-1);
}
if (fread(&ehdr, sizeof ehdr, 1, iop) != 1 ||
ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
ehdr.e_ident[EI_MAG3] != ELFMAG3) {
warnx("%s: not an ELF file", filename);
fclose(iop);
return (-1);
}
if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
warnx("%s: unsupported ELF version", filename);
fclose(iop);
return (-1);
}
if (ehdr.e_ident[EI_DATA] != my_byte_order()) {
warnx("%s: unsupported byte order", filename);
fclose(iop);
return (-1);
}
if (ehdr.e_shoff == 0) {
warnx("%s: no section table", filename);
fclose(iop);
return (-1);
}
if (ehdr.e_shstrndx == SHN_UNDEF) {
warnx("%s: no section name string table", filename);
fclose(iop);
return (-1);
}
shdr = NEW(Elf_Shdr, ehdr.e_shnum);
if (fseek(iop, ehdr.e_shoff, SEEK_SET) == -1) {
warn("%s", filename);
free(shdr);
fclose(iop);
return (-1);
}
if (fread(shdr, sizeof *shdr, ehdr.e_shnum, iop) != ehdr.e_shnum) {
warnx("%s: truncated section table", filename);
free(shdr);
fclose(iop);
return (-1);
}
shstr = NEW(char, shdr[ehdr.e_shstrndx].sh_size);
if (fseek(iop, shdr[ehdr.e_shstrndx].sh_offset, SEEK_SET) == -1) {
warn("%s", filename);
free(shstr);
free(shdr);
fclose(iop);
return (-1);
}
if (fread(shstr, sizeof *shstr, shdr[ehdr.e_shstrndx].sh_size, iop) !=
shdr[ehdr.e_shstrndx].sh_size) {
warnx("%s: truncated section name string table", filename);
free(shstr);
free(shdr);
fclose(iop);
return (-1);
}
for (i = 1; i < ehdr.e_shnum; i++) {
const char *name = shstr + shdr[i].sh_name;
if (strncmp(name, PREFIX, sizeof (PREFIX) - 1) == 0)
enter(name + sizeof (PREFIX) - 1, shdr[i].sh_size);
}
free(shstr);
free(shdr);
fclose(iop);
return (0);
}
/*
* Destructively merge all the sorted hash chains into a single sorted
* list, and return a pointer to its first element.
*/
static hashent *
merge(void)
{
unsigned int numchains = HASHSIZE;
while (numchains > 1) { /* More merging to do. */
unsigned int lo = 0;
/*
* Merge chains pairwise from the outside in, halving the
* number of chains.
*/
while (numchains - lo >= 2) {
hashent **linkp = &hashtab[lo];
hashent *l1 = hashtab[lo++];
hashent *l2 = hashtab[--numchains];
while (l1 != NULL && l2 != NULL) {
if (strcmp(l1->name, l2->name) < 0) {
*linkp = l1;
linkp = &l1->next;
l1 = l1->next;
} else {
*linkp = l2;
linkp = &l2->next;
l2 = l2->next;
}
}
*linkp = l1==NULL ? l2 : l1;
}
}
return (hashtab[0]);
}
/*
* Determine the host byte order.
*/
static int
my_byte_order(void)
{
static unsigned short s = 0xbbaa;
int byte0;
byte0 = *(unsigned char *)&s;
if (byte0 == 0xaa)
return (ELFDATA2LSB);
else if (byte0 == 0xbb)
return (ELFDATA2MSB);
else
return (ELFDATANONE);
}
/*
* Allocate a chunk of memory and return a pointer to it. Die if the
* malloc fails.
*/
static void *
xmalloc(size_t size)
{
void *p;
p = malloc(size);
if (p == NULL)
err(EXIT_FAILURE, "malloc");
return (p);
}
/*
* Duplicate a string and return a pointer to the copy. Die if there is
* not enough memory.
*/
static char *
xstrdup(const char *s)
{
int size;
size = strlen(s) + 1;
return (memcpy(xmalloc(size), s, size));
}