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nasm/output/outelf32.c
Charles Crayne dcd3a21145 ELF32 bit support of .tdata and .tbss sections 
Set default attributes for .tdata and .tbss sections
Implement new attribute 'tls' for arbitrary section names
Flag variables in sections with tls attribute with STT_TLS
2008-10-30 21:59:42 -07:00

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/* outelf.c output routines for the Netwide Assembler to produce
* ELF32 (i386 of course) object file format
*
* The Netwide Assembler is copyright (C) 1996 Simon Tatham and
* Julian Hall. All rights reserved. The software is
* redistributable under the license given in the file "LICENSE"
* distributed in the NASM archive.
*/
#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <inttypes.h>
#include "nasm.h"
#include "nasmlib.h"
#include "saa.h"
#include "raa.h"
#include "stdscan.h"
#include "outform.h"
#include "outlib.h"
#ifdef OF_ELF32
/*
* Relocation types.
*/
enum reloc_type {
R_386_32 = 1, /* ordinary absolute relocation */
R_386_PC32 = 2, /* PC-relative relocation */
R_386_GOT32 = 3, /* an offset into GOT */
R_386_PLT32 = 4, /* a PC-relative offset into PLT */
R_386_COPY = 5, /* ??? */
R_386_GLOB_DAT = 6, /* ??? */
R_386_JUMP_SLOT = 7, /* ??? */
R_386_RELATIVE = 8, /* ??? */
R_386_GOTOFF = 9, /* an offset from GOT base */
R_386_GOTPC = 10, /* a PC-relative offset _to_ GOT */
/* These are GNU extensions, but useful */
R_386_16 = 20, /* A 16-bit absolute relocation */
R_386_PC16 = 21, /* A 16-bit PC-relative relocation */
R_386_8 = 22, /* An 8-bit absolute relocation */
R_386_PC8 = 23 /* An 8-bit PC-relative relocation */
};
struct Reloc {
struct Reloc *next;
int32_t address; /* relative to _start_ of section */
int32_t symbol; /* symbol index */
int type; /* type of relocation */
};
struct Symbol {
int32_t strpos; /* string table position of name */
int32_t section; /* section ID of the symbol */
int type; /* symbol type */
int other; /* symbol visibility */
int32_t value; /* address, or COMMON variable align */
int32_t size; /* size of symbol */
int32_t globnum; /* symbol table offset if global */
struct Symbol *next; /* list of globals in each section */
struct Symbol *nextfwd; /* list of unresolved-size symbols */
char *name; /* used temporarily if in above list */
};
#define SHT_PROGBITS 1
#define SHT_NOBITS 8
#define SHF_WRITE 1
#define SHF_ALLOC 2
#define SHF_EXECINSTR 4
#define SHF_TLS (1 << 10) /* Section holds thread-local data. */
struct Section {
struct SAA *data;
uint32_t len, size, nrelocs;
int32_t index;
int type; /* SHT_PROGBITS or SHT_NOBITS */
int align; /* alignment: power of two */
uint32_t flags; /* section flags */
char *name;
struct SAA *rel;
int32_t rellen;
struct Reloc *head, **tail;
struct Symbol *gsyms; /* global symbols in section */
};
#define SECT_DELTA 32
static struct Section **sects;
static int nsects, sectlen;
#define SHSTR_DELTA 256
static char *shstrtab;
static int shstrtablen, shstrtabsize;
static struct SAA *syms;
static uint32_t nlocals, nglobs;
static int32_t def_seg;
static struct RAA *bsym;
static struct SAA *strs;
static uint32_t strslen;
static FILE *elffp;
static efunc error;
static evalfunc evaluate;
static struct Symbol *fwds;
static char elf_module[FILENAME_MAX];
static uint8_t elf_osabi = 0; /* Default OSABI = 0 (System V or Linux) */
static uint8_t elf_abiver = 0; /* Current ABI version */
extern struct ofmt of_elf32;
extern struct ofmt of_elf;
#define SHN_ABS 0xFFF1
#define SHN_COMMON 0xFFF2
#define SHN_UNDEF 0
#define SYM_GLOBAL 0x10
#define SHT_RELA 4 /* Relocation entries with addends */
#define STT_NOTYPE 0 /* Symbol type is unspecified */
#define STT_OBJECT 1 /* Symbol is a data object */
#define STT_FUNC 2 /* Symbol is a code object */
#define STT_SECTION 3 /* Symbol associated with a section */
#define STT_FILE 4 /* Symbol's name is file name */
#define STT_COMMON 5 /* Symbol is a common data object */
#define STT_TLS 6 /* Symbol is thread-local data object*/
#define STT_NUM 7 /* Number of defined types. */
#define STV_DEFAULT 0
#define STV_INTERNAL 1
#define STV_HIDDEN 2
#define STV_PROTECTED 3
#define GLOBAL_TEMP_BASE 1048576 /* bigger than any reasonable sym id */
#define SEG_ALIGN 16 /* alignment of sections in file */
#define SEG_ALIGN_1 (SEG_ALIGN-1)
/* Definitions in lieu of dwarf.h */
#define DW_TAG_compile_unit 0x11
#define DW_TAG_subprogram 0x2e
#define DW_AT_name 0x03
#define DW_AT_stmt_list 0x10
#define DW_AT_low_pc 0x11
#define DW_AT_high_pc 0x12
#define DW_AT_language 0x13
#define DW_AT_producer 0x25
#define DW_AT_frame_base 0x40
#define DW_FORM_addr 0x01
#define DW_FORM_data2 0x05
#define DW_FORM_data4 0x06
#define DW_FORM_string 0x08
#define DW_LNS_extended_op 0
#define DW_LNS_advance_pc 2
#define DW_LNS_advance_line 3
#define DW_LNS_set_file 4
#define DW_LNE_end_sequence 1
#define DW_LNE_set_address 2
#define DW_LNE_define_file 3
#define DW_LANG_Mips_Assembler 0x8001
#define SOC(ln,aa) ln - line_base + (line_range * aa) + opcode_base
static const char align_str[SEG_ALIGN] = ""; /* ANSI will pad this with 0s */
static struct ELF_SECTDATA {
void *data;
int32_t len;
bool is_saa;
} *elf_sects;
static int elf_nsect, nsections;
static int32_t elf_foffs;
static void elf_write(void);
static void elf_sect_write(struct Section *, const uint8_t *,
uint32_t);
static void elf_section_header(int, int, int, void *, bool, int32_t, int, int,
int, int);
static void elf_write_sections(void);
static struct SAA *elf_build_symtab(int32_t *, int32_t *);
static struct SAA *elf_build_reltab(int32_t *, struct Reloc *);
static void add_sectname(char *, char *);
/* this stuff is needed for the stabs debugging format */
#define N_SO 0x64 /* ID for main source file */
#define N_SOL 0x84 /* ID for sub-source file */
#define N_BINCL 0x82
#define N_EINCL 0xA2
#define N_SLINE 0x44
#define TY_STABSSYMLIN 0x40 /* ouch */
struct stabentry {
uint32_t n_strx;
uint8_t n_type;
uint8_t n_other;
uint16_t n_desc;
uint32_t n_value;
};
struct erel {
int offset, info;
};
struct symlininfo {
int offset;
int section; /* section index */
char *name; /* shallow-copied pointer of section name */
};
struct linelist {
struct symlininfo info;
int line;
char *filename;
struct linelist *next;
struct linelist *last;
};
struct sectlist {
struct SAA *psaa;
int section;
int line;
int offset;
int file;
struct sectlist *next;
struct sectlist *last;
};
/* common debug variables */
static int currentline = 1;
static int debug_immcall = 0;
/* stabs debug variables */
static struct linelist *stabslines = 0;
static int numlinestabs = 0;
static char *stabs_filename = 0;
static int symtabsection;
static uint8_t *stabbuf = 0, *stabstrbuf = 0, *stabrelbuf = 0;
static int stablen, stabstrlen, stabrellen;
/* dwarf debug variables */
static struct linelist *dwarf_flist = 0, *dwarf_clist = 0, *dwarf_elist = 0;
static struct sectlist *dwarf_fsect = 0, *dwarf_csect = 0, *dwarf_esect = 0;
static int dwarf_numfiles = 0, dwarf_nsections;
static uint8_t *arangesbuf = 0, *arangesrelbuf = 0, *pubnamesbuf = 0, *infobuf = 0, *inforelbuf = 0,
*abbrevbuf = 0, *linebuf = 0, *linerelbuf = 0, *framebuf = 0, *locbuf = 0;
static int8_t line_base = -5, line_range = 14, opcode_base = 13;
static int arangeslen, arangesrellen, pubnameslen, infolen, inforellen,
abbrevlen, linelen, linerellen, framelen, loclen;
static int32_t dwarf_infosym, dwarf_abbrevsym, dwarf_linesym;
static struct dfmt df_dwarf;
static struct dfmt df_stabs;
static struct Symbol *lastsym;
/* common debugging routines */
void debug32_typevalue(int32_t);
void debug32_init(struct ofmt *, void *, FILE *, efunc);
void debug32_deflabel(char *, int32_t, int64_t, int, char *);
void debug32_directive(const char *, const char *);
/* stabs debugging routines */
void stabs32_linenum(const char *filename, int32_t linenumber, int32_t);
void stabs32_output(int, void *);
void stabs32_generate(void);
void stabs32_cleanup(void);
/* dwarf debugging routines */
void dwarf32_linenum(const char *filename, int32_t linenumber, int32_t);
void dwarf32_output(int, void *);
void dwarf32_generate(void);
void dwarf32_cleanup(void);
void dwarf32_findfile(const char *);
void dwarf32_findsect(const int);
void saa_wleb128u(struct SAA *, int);
void saa_wleb128s(struct SAA *, int);
/*
* Special section numbers which are used to define ELF special
* symbols, which can be used with WRT to provide PIC relocation
* types.
*/
static int32_t elf_gotpc_sect, elf_gotoff_sect;
static int32_t elf_got_sect, elf_plt_sect;
static int32_t elf_sym_sect;
static void elf_init(FILE * fp, efunc errfunc, ldfunc ldef, evalfunc eval)
{
if (of_elf.current_dfmt != &null_debug_form)
of_elf32.current_dfmt = of_elf.current_dfmt;
elffp = fp;
error = errfunc;
evaluate = eval;
(void)ldef; /* placate optimisers */
sects = NULL;
nsects = sectlen = 0;
syms = saa_init((int32_t)sizeof(struct Symbol));
nlocals = nglobs = 0;
bsym = raa_init();
strs = saa_init(1L);
saa_wbytes(strs, "\0", 1L);
saa_wbytes(strs, elf_module, strlen(elf_module)+1);
strslen = 2 + strlen(elf_module);
shstrtab = NULL;
shstrtablen = shstrtabsize = 0;;
add_sectname("", "");
fwds = NULL;
elf_gotpc_sect = seg_alloc();
ldef("..gotpc", elf_gotpc_sect + 1, 0L, NULL, false, false, &of_elf32,
error);
elf_gotoff_sect = seg_alloc();
ldef("..gotoff", elf_gotoff_sect + 1, 0L, NULL, false, false, &of_elf32,
error);
elf_got_sect = seg_alloc();
ldef("..got", elf_got_sect + 1, 0L, NULL, false, false, &of_elf32,
error);
elf_plt_sect = seg_alloc();
ldef("..plt", elf_plt_sect + 1, 0L, NULL, false, false, &of_elf32,
error);
elf_sym_sect = seg_alloc();
ldef("..sym", elf_sym_sect + 1, 0L, NULL, false, false, &of_elf32,
error);
def_seg = seg_alloc();
}
static void elf_cleanup(int debuginfo)
{
struct Reloc *r;
int i;
(void)debuginfo;
elf_write();
fclose(elffp);
for (i = 0; i < nsects; i++) {
if (sects[i]->type != SHT_NOBITS)
saa_free(sects[i]->data);
if (sects[i]->head)
saa_free(sects[i]->rel);
while (sects[i]->head) {
r = sects[i]->head;
sects[i]->head = sects[i]->head->next;
nasm_free(r);
}
}
nasm_free(sects);
saa_free(syms);
raa_free(bsym);
saa_free(strs);
if (of_elf32.current_dfmt) {
of_elf32.current_dfmt->cleanup();
}
}
static void add_sectname(char *firsthalf, char *secondhalf)
{
int len = strlen(firsthalf) + strlen(secondhalf);
while (shstrtablen + len + 1 > shstrtabsize)
shstrtab = nasm_realloc(shstrtab, (shstrtabsize += SHSTR_DELTA));
strcpy(shstrtab + shstrtablen, firsthalf);
strcat(shstrtab + shstrtablen, secondhalf);
shstrtablen += len + 1;
}
static int elf_make_section(char *name, int type, int flags, int align)
{
struct Section *s;
s = nasm_malloc(sizeof(*s));
if (type != SHT_NOBITS)
s->data = saa_init(1L);
s->head = NULL;
s->tail = &s->head;
s->len = s->size = 0;
s->nrelocs = 0;
if (!strcmp(name, ".text"))
s->index = def_seg;
else
s->index = seg_alloc();
add_sectname("", name);
s->name = nasm_malloc(1 + strlen(name));
strcpy(s->name, name);
s->type = type;
s->flags = flags;
s->align = align;
s->gsyms = NULL;
if (nsects >= sectlen)
sects =
nasm_realloc(sects, (sectlen += SECT_DELTA) * sizeof(*sects));
sects[nsects++] = s;
return nsects - 1;
}
static int32_t elf_section_names(char *name, int pass, int *bits)
{
char *p;
unsigned flags_and, flags_or;
int type, align, i;
/*
* Default is 32 bits.
*/
if (!name) {
*bits = 32;
return def_seg;
}
p = name;
while (*p && !nasm_isspace(*p))
p++;
if (*p)
*p++ = '\0';
flags_and = flags_or = type = align = 0;
while (*p && nasm_isspace(*p))
p++;
while (*p) {
char *q = p;
while (*p && !nasm_isspace(*p))
p++;
if (*p)
*p++ = '\0';
while (*p && nasm_isspace(*p))
p++;
if (!nasm_strnicmp(q, "align=", 6)) {
align = atoi(q + 6);
if (align == 0)
align = 1;
if ((align - 1) & align) { /* means it's not a power of two */
error(ERR_NONFATAL, "section alignment %d is not"
" a power of two", align);
align = 1;
}
} else if (!nasm_stricmp(q, "alloc")) {
flags_and |= SHF_ALLOC;
flags_or |= SHF_ALLOC;
} else if (!nasm_stricmp(q, "noalloc")) {
flags_and |= SHF_ALLOC;
flags_or &= ~SHF_ALLOC;
} else if (!nasm_stricmp(q, "exec")) {
flags_and |= SHF_EXECINSTR;
flags_or |= SHF_EXECINSTR;
} else if (!nasm_stricmp(q, "noexec")) {
flags_and |= SHF_EXECINSTR;
flags_or &= ~SHF_EXECINSTR;
} else if (!nasm_stricmp(q, "write")) {
flags_and |= SHF_WRITE;
flags_or |= SHF_WRITE;
} else if (!nasm_stricmp(q, "tls")) {
flags_and |= SHF_TLS;
flags_or |= SHF_TLS;
} else if (!nasm_stricmp(q, "nowrite")) {
flags_and |= SHF_WRITE;
flags_or &= ~SHF_WRITE;
} else if (!nasm_stricmp(q, "progbits")) {
type = SHT_PROGBITS;
} else if (!nasm_stricmp(q, "nobits")) {
type = SHT_NOBITS;
}
}
if (!strcmp(name, ".comment") ||
!strcmp(name, ".shstrtab") ||
!strcmp(name, ".symtab") || !strcmp(name, ".strtab")) {
error(ERR_NONFATAL, "attempt to redefine reserved section"
"name `%s'", name);
return NO_SEG;
}
for (i = 0; i < nsects; i++)
if (!strcmp(name, sects[i]->name))
break;
if (i == nsects) {
if (!strcmp(name, ".text"))
i = elf_make_section(name, SHT_PROGBITS,
SHF_ALLOC | SHF_EXECINSTR, 16);
else if (!strcmp(name, ".rodata"))
i = elf_make_section(name, SHT_PROGBITS, SHF_ALLOC, 4);
else if (!strcmp(name, ".data"))
i = elf_make_section(name, SHT_PROGBITS,
SHF_ALLOC | SHF_WRITE, 4);
else if (!strcmp(name, ".bss"))
i = elf_make_section(name, SHT_NOBITS,
SHF_ALLOC | SHF_WRITE, 4);
else if (!strcmp(name, ".tdata"))
i = elf_make_section(name, SHT_PROGBITS,
SHF_ALLOC | SHF_WRITE | SHF_TLS, 4);
else if (!strcmp(name, ".tbss"))
i = elf_make_section(name, SHT_NOBITS,
SHF_ALLOC | SHF_WRITE | SHF_TLS, 4);
else
i = elf_make_section(name, SHT_PROGBITS, SHF_ALLOC, 1);
if (type)
sects[i]->type = type;
if (align)
sects[i]->align = align;
sects[i]->flags &= ~flags_and;
sects[i]->flags |= flags_or;
} else if (pass == 1) {
if ((type && sects[i]->type != type)
|| (align && sects[i]->align != align)
|| (flags_and && ((sects[i]->flags & flags_and) != flags_or)))
error(ERR_WARNING, "section attributes ignored on"
" redeclaration of section `%s'", name);
}
return sects[i]->index;
}
static void elf_deflabel(char *name, int32_t segment, int64_t offset,
int is_global, char *special)
{
int pos = strslen;
struct Symbol *sym;
bool special_used = false;
#if defined(DEBUG) && DEBUG>2
fprintf(stderr,
" elf_deflabel: %s, seg=%ld, off=%ld, is_global=%d, %s\n",
name, segment, offset, is_global, special);
#endif
if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
/*
* This is a NASM special symbol. We never allow it into
* the ELF symbol table, even if it's a valid one. If it
* _isn't_ a valid one, we should barf immediately.
*/
if (strcmp(name, "..gotpc") && strcmp(name, "..gotoff") &&
strcmp(name, "..got") && strcmp(name, "..plt") &&
strcmp(name, "..sym"))
error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
return;
}
if (is_global == 3) {
struct Symbol **s;
/*
* Fix up a forward-reference symbol size from the first
* pass.
*/
for (s = &fwds; *s; s = &(*s)->nextfwd)
if (!strcmp((*s)->name, name)) {
struct tokenval tokval;
expr *e;
char *p = special;
while (*p && !nasm_isspace(*p))
p++;
while (*p && nasm_isspace(*p))
p++;
stdscan_reset();
stdscan_bufptr = p;
tokval.t_type = TOKEN_INVALID;
e = evaluate(stdscan, NULL, &tokval, NULL, 1, error, NULL);
if (e) {
if (!is_simple(e))
error(ERR_NONFATAL, "cannot use relocatable"
" expression as symbol size");
else
(*s)->size = reloc_value(e);
}
/*
* Remove it from the list of unresolved sizes.
*/
nasm_free((*s)->name);
*s = (*s)->nextfwd;
return;
}
return; /* it wasn't an important one */
}
saa_wbytes(strs, name, (int32_t)(1 + strlen(name)));
strslen += 1 + strlen(name);
lastsym = sym = saa_wstruct(syms);
sym->strpos = pos;
sym->type = is_global ? SYM_GLOBAL : 0;
sym->other = STV_DEFAULT;
sym->size = 0;
if (segment == NO_SEG)
sym->section = SHN_ABS;
else {
int i;
sym->section = SHN_UNDEF;
if (nsects == 0 && segment == def_seg) {
int tempint;
if (segment != elf_section_names(".text", 2, &tempint))
error(ERR_PANIC,
"strange segment conditions in ELF driver");
sym->section = nsects;
} else {
for (i = 0; i < nsects; i++)
if (segment == sects[i]->index) {
sym->section = i + 1;
break;
}
}
}
if (is_global == 2) {
sym->size = offset;
sym->value = 0;
sym->section = SHN_COMMON;
/*
* We have a common variable. Check the special text to see
* if it's a valid number and power of two; if so, store it
* as the alignment for the common variable.
*/
if (special) {
bool err;
sym->value = readnum(special, &err);
if (err)
error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" valid number", special);
else if ((sym->value | (sym->value - 1)) != 2 * sym->value - 1)
error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" power of two", special);
}
special_used = true;
} else
sym->value = (sym->section == SHN_UNDEF ? 0 : offset);
if (sym->type == SYM_GLOBAL) {
/*
* If sym->section == SHN_ABS, then the first line of the
* else section would cause a core dump, because its a reference
* beyond the end of the section array.
* This behaviour is exhibited by this code:
* GLOBAL crash_nasm
* crash_nasm equ 0
* To avoid such a crash, such requests are silently discarded.
* This may not be the best solution.
*/
if (sym->section == SHN_UNDEF || sym->section == SHN_COMMON) {
bsym = raa_write(bsym, segment, nglobs);
} else if (sym->section != SHN_ABS) {
/*
* This is a global symbol; so we must add it to the linked
* list of global symbols in its section. We'll push it on
* the beginning of the list, because it doesn't matter
* much which end we put it on and it's easier like this.
*
* In addition, we check the special text for symbol
* type and size information.
*/
sym->next = sects[sym->section - 1]->gsyms;
sects[sym->section - 1]->gsyms = sym;
if (special) {
int n = strcspn(special, " \t");
if (!nasm_strnicmp(special, "function", n))
sym->type |= STT_FUNC;
else if (!nasm_strnicmp(special, "data", n) ||
!nasm_strnicmp(special, "object", n))
sym->type |= STT_OBJECT;
else if (!nasm_strnicmp(special, "notype", n))
sym->type |= STT_NOTYPE;
else
error(ERR_NONFATAL, "unrecognised symbol type `%.*s'",
n, special);
special += n;
while (nasm_isspace(*special))
++special;
if (*special) {
n = strcspn(special, " \t");
if (!nasm_strnicmp(special, "default", n))
sym->other = STV_DEFAULT;
else if (!nasm_strnicmp(special, "internal", n))
sym->other = STV_INTERNAL;
else if (!nasm_strnicmp(special, "hidden", n))
sym->other = STV_HIDDEN;
else if (!nasm_strnicmp(special, "protected", n))
sym->other = STV_PROTECTED;
else
n = 0;
special += n;
}
if (*special) {
struct tokenval tokval;
expr *e;
int fwd = 0;
char *saveme = stdscan_bufptr; /* bugfix? fbk 8/10/00 */
while (special[n] && nasm_isspace(special[n]))
n++;
/*
* We have a size expression; attempt to
* evaluate it.
*/
stdscan_reset();
stdscan_bufptr = special + n;
tokval.t_type = TOKEN_INVALID;
e = evaluate(stdscan, NULL, &tokval, &fwd, 0, error,
NULL);
if (fwd) {
sym->nextfwd = fwds;
fwds = sym;
sym->name = nasm_strdup(name);
} else if (e) {
if (!is_simple(e))
error(ERR_NONFATAL, "cannot use relocatable"
" expression as symbol size");
else
sym->size = reloc_value(e);
}
stdscan_bufptr = saveme; /* bugfix? fbk 8/10/00 */
}
special_used = true;
}
/*
* If TLS segment, mark symbol accordingly.
*/
if (sects[sym->section - 1]->flags & SHF_TLS) {
sym->type &= 0xf0;
sym->type |= STT_TLS;
}
}
sym->globnum = nglobs;
nglobs++;
} else
nlocals++;
if (special && !special_used)
error(ERR_NONFATAL, "no special symbol features supported here");
}
static void elf_add_reloc(struct Section *sect, int32_t segment, int type)
{
struct Reloc *r;
r = *sect->tail = nasm_malloc(sizeof(struct Reloc));
sect->tail = &r->next;
r->next = NULL;
r->address = sect->len;
if (segment == NO_SEG)
r->symbol = 0;
else {
int i;
r->symbol = 0;
for (i = 0; i < nsects; i++)
if (segment == sects[i]->index)
r->symbol = i + 2;
if (!r->symbol)
r->symbol = GLOBAL_TEMP_BASE + raa_read(bsym, segment);
}
r->type = type;
sect->nrelocs++;
}
/*
* This routine deals with ..got and ..sym relocations: the more
* complicated kinds. In shared-library writing, some relocations
* with respect to global symbols must refer to the precise symbol
* rather than referring to an offset from the base of the section
* _containing_ the symbol. Such relocations call to this routine,
* which searches the symbol list for the symbol in question.
*
* R_386_GOT32 references require the _exact_ symbol address to be
* used; R_386_32 references can be at an offset from the symbol.
* The boolean argument `exact' tells us this.
*
* Return value is the adjusted value of `addr', having become an
* offset from the symbol rather than the section. Should always be
* zero when returning from an exact call.
*
* Limitation: if you define two symbols at the same place,
* confusion will occur.
*
* Inefficiency: we search, currently, using a linked list which
* isn't even necessarily sorted.
*/
static int32_t elf_add_gsym_reloc(struct Section *sect,
int32_t segment, int32_t offset,
int type, bool exact)
{
struct Reloc *r;
struct Section *s;
struct Symbol *sym, *sm;
int i;
/*
* First look up the segment/offset pair and find a global
* symbol corresponding to it. If it's not one of our segments,
* then it must be an external symbol, in which case we're fine
* doing a normal elf_add_reloc after first sanity-checking
* that the offset from the symbol is zero.
*/
s = NULL;
for (i = 0; i < nsects; i++)
if (segment == sects[i]->index) {
s = sects[i];
break;
}
if (!s) {
if (exact && offset != 0)
error(ERR_NONFATAL, "unable to find a suitable global symbol"
" for this reference");
else
elf_add_reloc(sect, segment, type);
return offset;
}
if (exact) {
/*
* Find a symbol pointing _exactly_ at this one.
*/
for (sym = s->gsyms; sym; sym = sym->next)
if (sym->value == offset)
break;
} else {
/*
* Find the nearest symbol below this one.
*/
sym = NULL;
for (sm = s->gsyms; sm; sm = sm->next)
if (sm->value <= offset && (!sym || sm->value > sym->value))
sym = sm;
}
if (!sym && exact) {
error(ERR_NONFATAL, "unable to find a suitable global symbol"
" for this reference");
return 0;
}
r = *sect->tail = nasm_malloc(sizeof(struct Reloc));
sect->tail = &r->next;
r->next = NULL;
r->address = sect->len;
r->symbol = GLOBAL_TEMP_BASE + sym->globnum;
r->type = type;
sect->nrelocs++;
return offset - sym->value;
}
static void elf_out(int32_t segto, const void *data,
enum out_type type, uint64_t size,
int32_t segment, int32_t wrt)
{
struct Section *s;
int32_t addr;
uint8_t mydata[4], *p;
int i;
static struct symlininfo sinfo;
/*
* handle absolute-assembly (structure definitions)
*/
if (segto == NO_SEG) {
if (type != OUT_RESERVE)
error(ERR_NONFATAL, "attempt to assemble code in [ABSOLUTE]"
" space");
return;
}
s = NULL;
for (i = 0; i < nsects; i++)
if (segto == sects[i]->index) {
s = sects[i];
break;
}
if (!s) {
int tempint; /* ignored */
if (segto != elf_section_names(".text", 2, &tempint))
error(ERR_PANIC, "strange segment conditions in ELF driver");
else {
s = sects[nsects - 1];
i = nsects - 1;
}
}
/* again some stabs debugging stuff */
if (of_elf32.current_dfmt) {
sinfo.offset = s->len;
sinfo.section = i;
sinfo.name = s->name;
of_elf32.current_dfmt->debug_output(TY_STABSSYMLIN, &sinfo);
}
/* end of debugging stuff */
if (s->type == SHT_NOBITS && type != OUT_RESERVE) {
error(ERR_WARNING, "attempt to initialize memory in"
" BSS section `%s': ignored", s->name);
s->len += realsize(type, size);
return;
}
if (type == OUT_RESERVE) {
if (s->type == SHT_PROGBITS) {
error(ERR_WARNING, "uninitialized space declared in"
" non-BSS section `%s': zeroing", s->name);
elf_sect_write(s, NULL, size);
} else
s->len += size;
} else if (type == OUT_RAWDATA) {
if (segment != NO_SEG)
error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
elf_sect_write(s, data, size);
} else if (type == OUT_ADDRESS) {
bool gnu16 = false;
addr = *(int64_t *)data;
if (segment != NO_SEG) {
if (segment % 2) {
error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
if (size == 2) {
gnu16 = true;
elf_add_reloc(s, segment, R_386_16);
} else {
elf_add_reloc(s, segment, R_386_32);
}
} else if (wrt == elf_gotpc_sect + 1) {
/*
* The user will supply GOT relative to $$. ELF
* will let us have GOT relative to $. So we
* need to fix up the data item by $-$$.
*/
addr += s->len;
elf_add_reloc(s, segment, R_386_GOTPC);
} else if (wrt == elf_gotoff_sect + 1) {
elf_add_reloc(s, segment, R_386_GOTOFF);
} else if (wrt == elf_got_sect + 1) {
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_GOT32, true);
} else if (wrt == elf_sym_sect + 1) {
if (size == 2) {
gnu16 = true;
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_16, false);
} else {
addr = elf_add_gsym_reloc(s, segment, addr,
R_386_32, false);
}
} else if (wrt == elf_plt_sect + 1) {
error(ERR_NONFATAL, "ELF format cannot produce non-PC-"
"relative PLT references");
} else {
error(ERR_NONFATAL, "ELF format does not support this"
" use of WRT");
wrt = NO_SEG; /* we can at least _try_ to continue */
}
}
}
p = mydata;
if (gnu16) {
error(ERR_WARNING | ERR_WARN_GNUELF,
"16-bit relocations in ELF is a GNU extension");
WRITESHORT(p, addr);
} else {
if (size != 4 && segment != NO_SEG) {
error(ERR_NONFATAL,
"Unsupported non-32-bit ELF relocation");
}
WRITELONG(p, addr);
}
elf_sect_write(s, mydata, size);
} else if (type == OUT_REL2ADR) {
if (segment == segto)
error(ERR_PANIC, "intra-segment OUT_REL2ADR");
if (segment != NO_SEG && segment % 2) {
error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
error(ERR_WARNING | ERR_WARN_GNUELF,
"16-bit relocations in ELF is a GNU extension");
elf_add_reloc(s, segment, R_386_PC16);
} else {
error(ERR_NONFATAL,
"Unsupported non-32-bit ELF relocation");
}
}
p = mydata;
WRITESHORT(p, *(int64_t *)data - size);
elf_sect_write(s, mydata, 2L);
} else if (type == OUT_REL4ADR) {
if (segment == segto)
error(ERR_PANIC, "intra-segment OUT_REL4ADR");
if (segment != NO_SEG && segment % 2) {
error(ERR_NONFATAL, "ELF format does not support"
" segment base references");
} else {
if (wrt == NO_SEG) {
elf_add_reloc(s, segment, R_386_PC32);
} else if (wrt == elf_plt_sect + 1) {
elf_add_reloc(s, segment, R_386_PLT32);
} else if (wrt == elf_gotpc_sect + 1 ||
wrt == elf_gotoff_sect + 1 ||
wrt == elf_got_sect + 1) {
error(ERR_NONFATAL, "ELF format cannot produce PC-"
"relative GOT references");
} else {
error(ERR_NONFATAL, "ELF format does not support this"
" use of WRT");
wrt = NO_SEG; /* we can at least _try_ to continue */
}
}
p = mydata;
WRITELONG(p, *(int64_t *)data - size);
elf_sect_write(s, mydata, 4L);
}
}
static void elf_write(void)
{
int align;
int scount;
char *p;
int commlen;
char comment[64];
int i;
struct SAA *symtab;
int32_t symtablen, symtablocal;
/*
* Work out how many sections we will have. We have SHN_UNDEF,
* then the flexible user sections, then the four fixed
* sections `.comment', `.shstrtab', `.symtab' and `.strtab',
* then optionally relocation sections for the user sections.
*/
if (of_elf32.current_dfmt == &df_stabs)
nsections = 8;
else if (of_elf32.current_dfmt == &df_dwarf)
nsections = 15;
else
nsections = 5; /* SHN_UNDEF and the fixed ones */
add_sectname("", ".comment");
add_sectname("", ".shstrtab");
add_sectname("", ".symtab");
add_sectname("", ".strtab");
for (i = 0; i < nsects; i++) {
nsections++; /* for the section itself */
if (sects[i]->head) {
nsections++; /* for its relocations */
add_sectname(".rel", sects[i]->name);
}
}
if (of_elf32.current_dfmt == &df_stabs) {
/* in case the debug information is wanted, just add these three sections... */
add_sectname("", ".stab");
add_sectname("", ".stabstr");
add_sectname(".rel", ".stab");
}
else if (of_elf32.current_dfmt == &df_dwarf) {
/* the dwarf debug standard specifies the following ten sections,
not all of which are currently implemented,
although all of them are defined. */
#define debug_aranges (int32_t) (nsections-10)
#define debug_info (int32_t) (nsections-7)
#define debug_abbrev (int32_t) (nsections-5)
#define debug_line (int32_t) (nsections-4)
add_sectname("", ".debug_aranges");
add_sectname(".rela", ".debug_aranges");
add_sectname("", ".debug_pubnames");
add_sectname("", ".debug_info");
add_sectname(".rela", ".debug_info");
add_sectname("", ".debug_abbrev");
add_sectname("", ".debug_line");
add_sectname(".rela", ".debug_line");
add_sectname("", ".debug_frame");
add_sectname("", ".debug_loc");
}
/*
* Do the comment.
*/
*comment = '\0';
commlen =
2 + sprintf(comment + 1, "The Netwide Assembler %s", NASM_VER);
/*
* Output the ELF header.
*/
fwrite("\177ELF\1\1\1", 7, 1, elffp);
fputc(elf_osabi, elffp);
fputc(elf_abiver, elffp);
fwrite("\0\0\0\0\0\0\0", 7, 1, elffp);
fwriteint16_t(1, elffp); /* ET_REL relocatable file */
fwriteint16_t(3, elffp); /* EM_386 processor ID */
fwriteint32_t(1L, elffp); /* EV_CURRENT file format version */
fwriteint32_t(0L, elffp); /* no entry point */
fwriteint32_t(0L, elffp); /* no program header table */
fwriteint32_t(0x40L, elffp); /* section headers straight after
* ELF header plus alignment */
fwriteint32_t(0L, elffp); /* 386 defines no special flags */
fwriteint16_t(0x34, elffp); /* size of ELF header */
fwriteint16_t(0, elffp); /* no program header table, again */
fwriteint16_t(0, elffp); /* still no program header table */
fwriteint16_t(0x28, elffp); /* size of section header */
fwriteint16_t(nsections, elffp); /* number of sections */
fwriteint16_t(nsects + 2, elffp); /* string table section index for
* section header table */
fwriteint32_t(0L, elffp); /* align to 0x40 bytes */
fwriteint32_t(0L, elffp);
fwriteint32_t(0L, elffp);
/*
* Build the symbol table and relocation tables.
*/
symtab = elf_build_symtab(&symtablen, &symtablocal);
for (i = 0; i < nsects; i++)
if (sects[i]->head)
sects[i]->rel = elf_build_reltab(&sects[i]->rellen,
sects[i]->head);
/*
* Now output the section header table.
*/
elf_foffs = 0x40 + 0x28 * nsections;
align = ((elf_foffs + SEG_ALIGN_1) & ~SEG_ALIGN_1) - elf_foffs;
elf_foffs += align;
elf_nsect = 0;
elf_sects = nasm_malloc(sizeof(*elf_sects) * nsections);
elf_section_header(0, 0, 0, NULL, false, 0L, 0, 0, 0, 0); /* SHN_UNDEF */
scount = 1; /* needed for the stabs debugging to track the symtable section */
p = shstrtab + 1;
for (i = 0; i < nsects; i++) {
elf_section_header(p - shstrtab, sects[i]->type, sects[i]->flags,
(sects[i]->type == SHT_PROGBITS ?
sects[i]->data : NULL), true,
sects[i]->len, 0, 0, sects[i]->align, 0);
p += strlen(p) + 1;
scount++; /* dito */
}
elf_section_header(p - shstrtab, 1, 0, comment, false, (int32_t)commlen, 0, 0, 1, 0); /* .comment */
scount++; /* dito */
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 3, 0, shstrtab, false, (int32_t)shstrtablen, 0, 0, 1, 0); /* .shstrtab */
scount++; /* dito */
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 2, 0, symtab, true, symtablen, nsects + 4, symtablocal, 4, 16); /* .symtab */
symtabsection = scount; /* now we got the symtab section index in the ELF file */
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 3, 0, strs, true, strslen, 0, 0, 1, 0); /* .strtab */
for (i = 0; i < nsects; i++)
if (sects[i]->head) {
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 9, 0, sects[i]->rel, true,
sects[i]->rellen, nsects + 3, i + 1, 4, 8);
}
if (of_elf32.current_dfmt == &df_stabs) {
/* for debugging information, create the last three sections
which are the .stab , .stabstr and .rel.stab sections respectively */
/* this function call creates the stab sections in memory */
stabs32_generate();
if ((stabbuf) && (stabstrbuf) && (stabrelbuf)) {
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 1, 0, stabbuf, false, stablen,
nsections - 2, 0, 4, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, 3, 0, stabstrbuf, false,
stabstrlen, 0, 0, 4, 0);
p += strlen(p) + 1;
/* link -> symtable info -> section to refer to */
elf_section_header(p - shstrtab, 9, 0, stabrelbuf, false,
stabrellen, symtabsection, nsections - 3, 4,
8);
}
}
else if (of_elf32.current_dfmt == &df_dwarf) {
/* for dwarf debugging information, create the ten dwarf sections */
/* this function call creates the dwarf sections in memory */
if (dwarf_fsect) dwarf32_generate();
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, arangesbuf, false,
arangeslen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, arangesrelbuf, false,
arangesrellen, symtabsection, debug_aranges, 1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, pubnamesbuf, false,
pubnameslen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, infobuf, false,
infolen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, inforelbuf, false,
inforellen, symtabsection, debug_info, 1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, abbrevbuf, false,
abbrevlen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, linebuf, false,
linelen, 0, 0, 1, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_RELA, 0, linerelbuf, false,
linerellen, symtabsection, debug_line, 1, 12);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, framebuf, false,
framelen, 0, 0, 8, 0);
p += strlen(p) + 1;
elf_section_header(p - shstrtab, SHT_PROGBITS, 0, locbuf, false,
loclen, 0, 0, 1, 0);
}
fwrite(align_str, align, 1, elffp);
/*
* Now output the sections.
*/
elf_write_sections();
nasm_free(elf_sects);
saa_free(symtab);
}
static struct SAA *elf_build_symtab(int32_t *len, int32_t *local)
{
struct SAA *s = saa_init(1L);
struct Symbol *sym;
uint8_t entry[16], *p;
int i;
*len = *local = 0;
/*
* First, an all-zeros entry, required by the ELF spec.
*/
saa_wbytes(s, NULL, 16L); /* null symbol table entry */
*len += 16;
(*local)++;
/*
* Next, an entry for the file name.
*/
p = entry;
WRITELONG(p, 1); /* we know it's 1st entry in strtab */
WRITELONG(p, 0); /* no value */
WRITELONG(p, 0); /* no size either */
WRITESHORT(p, STT_FILE); /* type FILE */
WRITESHORT(p, SHN_ABS);
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
/*
* Now some standard symbols defining the segments, for relocation
* purposes.
*/
for (i = 1; i <= nsects; i++) {
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, 0); /* offset zero */
WRITELONG(p, 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, i); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* Now the other local symbols.
*/
saa_rewind(syms);
while ((sym = saa_rstruct(syms))) {
if (sym->type & SYM_GLOBAL)
continue;
p = entry;
WRITELONG(p, sym->strpos);
WRITELONG(p, sym->value);
WRITELONG(p, sym->size);
WRITECHAR(p, sym->type); /* type and binding */
WRITECHAR(p, sym->other); /* visibility */
WRITESHORT(p, sym->section);
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* dwarf needs symbols for debug sections
* which are relocation targets.
*/
//*** fix for 32 bit
if (of_elf32.current_dfmt == &df_dwarf) {
dwarf_infosym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, debug_info); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
dwarf_abbrevsym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, debug_abbrev); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
dwarf_linesym = *local;
p = entry;
WRITELONG(p, 0); /* no symbol name */
WRITELONG(p, (uint32_t) 0); /* offset zero */
WRITELONG(p, (uint32_t) 0); /* size zero */
WRITESHORT(p, STT_SECTION); /* type, binding, and visibility */
WRITESHORT(p, debug_line); /* section id */
saa_wbytes(s, entry, 16L);
*len += 16;
(*local)++;
}
/*
* Now the global symbols.
*/
saa_rewind(syms);
while ((sym = saa_rstruct(syms))) {
if (!(sym->type & SYM_GLOBAL))
continue;
p = entry;
WRITELONG(p, sym->strpos);
WRITELONG(p, sym->value);
WRITELONG(p, sym->size);
WRITECHAR(p, sym->type); /* type and binding */
WRITECHAR(p, sym->other); /* visibility */
WRITESHORT(p, sym->section);
saa_wbytes(s, entry, 16L);
*len += 16;
}
return s;
}
static struct SAA *elf_build_reltab(int32_t *len, struct Reloc *r)
{
struct SAA *s;
uint8_t *p, entry[8];
if (!r)
return NULL;
s = saa_init(1L);
*len = 0;
while (r) {
int32_t sym = r->symbol;
if (sym >= GLOBAL_TEMP_BASE)
{
if (of_elf32.current_dfmt == &df_dwarf)
sym += -GLOBAL_TEMP_BASE + (nsects + 5) + nlocals;
else sym += -GLOBAL_TEMP_BASE + (nsects + 2) + nlocals;
}
p = entry;
WRITELONG(p, r->address);
WRITELONG(p, (sym << 8) + r->type);
saa_wbytes(s, entry, 8L);
*len += 8;
r = r->next;
}
return s;
}
static void elf_section_header(int name, int type, int flags,
void *data, bool is_saa, int32_t datalen,
int link, int info, int align, int eltsize)
{
elf_sects[elf_nsect].data = data;
elf_sects[elf_nsect].len = datalen;
elf_sects[elf_nsect].is_saa = is_saa;
elf_nsect++;
fwriteint32_t((int32_t)name, elffp);
fwriteint32_t((int32_t)type, elffp);
fwriteint32_t((int32_t)flags, elffp);
fwriteint32_t(0L, elffp); /* no address, ever, in object files */
fwriteint32_t(type == 0 ? 0L : elf_foffs, elffp);
fwriteint32_t(datalen, elffp);
if (data)
elf_foffs += (datalen + SEG_ALIGN_1) & ~SEG_ALIGN_1;
fwriteint32_t((int32_t)link, elffp);
fwriteint32_t((int32_t)info, elffp);
fwriteint32_t((int32_t)align, elffp);
fwriteint32_t((int32_t)eltsize, elffp);
}
static void elf_write_sections(void)
{
int i;
for (i = 0; i < elf_nsect; i++)
if (elf_sects[i].data) {
int32_t len = elf_sects[i].len;
int32_t reallen = (len + SEG_ALIGN_1) & ~SEG_ALIGN_1;
int32_t align = reallen - len;
if (elf_sects[i].is_saa)
saa_fpwrite(elf_sects[i].data, elffp);
else
fwrite(elf_sects[i].data, len, 1, elffp);
fwrite(align_str, align, 1, elffp);
}
}
static void elf_sect_write(struct Section *sect,
const uint8_t *data, uint32_t len)
{
saa_wbytes(sect->data, data, len);
sect->len += len;
}
static int32_t elf_segbase(int32_t segment)
{
return segment;
}
static int elf_directive(char *directive, char *value, int pass)
{
bool err;
int64_t n;
char *p;
if (!strcmp(directive, "osabi")) {
if (pass == 2)
return 1; /* ignore in pass 2 */
n = readnum(value, &err);
if (err) {
error(ERR_NONFATAL, "`osabi' directive requires a parameter");
return 1;
}
if (n < 0 || n > 255) {
error(ERR_NONFATAL, "valid osabi numbers are 0 to 255");
return 1;
}
elf_osabi = n;
elf_abiver = 0;
if ((p = strchr(value,',')) == NULL)
return 1;
n = readnum(p+1, &err);
if (err || n < 0 || n > 255) {
error(ERR_NONFATAL, "invalid ABI version number (valid: 0 to 255)");
return 1;
}
elf_abiver = n;
return 1;
}
return 0;
}
static void elf_filename(char *inname, char *outname, efunc error)
{
strcpy(elf_module, inname);
standard_extension(inname, outname, ".o", error);
}
extern macros_t elf_stdmac[];
static int elf_set_info(enum geninfo type, char **val)
{
(void)type;
(void)val;
return 0;
}
static struct dfmt df_dwarf = {
"ELF32 (i386) dwarf debug format for Linux",
"dwarf",
debug32_init,
dwarf32_linenum,
debug32_deflabel,
debug32_directive,
debug32_typevalue,
dwarf32_output,
dwarf32_cleanup
};
static struct dfmt df_stabs = {
"ELF32 (i386) stabs debug format for Linux",
"stabs",
debug32_init,
stabs32_linenum,
debug32_deflabel,
debug32_directive,
debug32_typevalue,
stabs32_output,
stabs32_cleanup
};
struct dfmt *elf32_debugs_arr[3] = { &df_stabs, &df_dwarf, NULL };
struct ofmt of_elf32 = {
"ELF32 (i386) object files (e.g. Linux)",
"elf32",
NULL,
elf32_debugs_arr,
&null_debug_form,
elf_stdmac,
elf_init,
elf_set_info,
elf_out,
elf_deflabel,
elf_section_names,
elf_segbase,
elf_directive,
elf_filename,
elf_cleanup
};
struct ofmt of_elf = {
"ELF (short name for ELF32) ",
"elf",
NULL,
elf32_debugs_arr,
&null_debug_form,
elf_stdmac,
elf_init,
elf_set_info,
elf_out,
elf_deflabel,
elf_section_names,
elf_segbase,
elf_directive,
elf_filename,
elf_cleanup
};
/* again, the stabs debugging stuff (code) */
void debug32_init(struct ofmt *of, void *id, FILE * fp, efunc error)
{
(void)of;
(void)id;
(void)fp;
(void)error;
}
void stabs32_linenum(const char *filename, int32_t linenumber, int32_t segto)
{
(void)segto;
if (!stabs_filename) {
stabs_filename = (char *)nasm_malloc(strlen(filename) + 1);
strcpy(stabs_filename, filename);
} else {
if (strcmp(stabs_filename, filename)) {
/* yep, a memory leak...this program is one-shot anyway, so who cares...
in fact, this leak comes in quite handy to maintain a list of files
encountered so far in the symbol lines... */
/* why not nasm_free(stabs_filename); we're done with the old one */
stabs_filename = (char *)nasm_malloc(strlen(filename) + 1);
strcpy(stabs_filename, filename);
}
}
debug_immcall = 1;
currentline = linenumber;
}
void debug32_deflabel(char *name, int32_t segment, int64_t offset, int is_global,
char *special)
{
(void)name;
(void)segment;
(void)offset;
(void)is_global;
(void)special;
}
void debug32_directive(const char *directive, const char *params)
{
(void)directive;
(void)params;
}
void debug32_typevalue(int32_t type)
{
int32_t stype, ssize;
switch (TYM_TYPE(type)) {
case TY_LABEL:
ssize = 0;
stype = STT_NOTYPE;
break;
case TY_BYTE:
ssize = 1;
stype = STT_OBJECT;
break;
case TY_WORD:
ssize = 2;
stype = STT_OBJECT;
break;
case TY_DWORD:
ssize = 4;
stype = STT_OBJECT;
break;
case TY_FLOAT:
ssize = 4;
stype = STT_OBJECT;
break;
case TY_QWORD:
ssize = 8;
stype = STT_OBJECT;
break;
case TY_TBYTE:
ssize = 10;
stype = STT_OBJECT;
break;
case TY_OWORD:
ssize = 8;
stype = STT_OBJECT;
break;
case TY_COMMON:
ssize = 0;
stype = STT_COMMON;
break;
case TY_SEG:
ssize = 0;
stype = STT_SECTION;
break;
case TY_EXTERN:
ssize = 0;
stype = STT_NOTYPE;
break;
case TY_EQU:
ssize = 0;
stype = STT_NOTYPE;
break;
default:
ssize = 0;
stype = STT_NOTYPE;
break;
}
if (stype == STT_OBJECT && lastsym && !lastsym->type) {
lastsym->size = ssize;
lastsym->type = stype;
}
}
void stabs32_output(int type, void *param)
{
struct symlininfo *s;
struct linelist *el;
if (type == TY_STABSSYMLIN) {
if (debug_immcall) {
s = (struct symlininfo *)param;
if (!(sects[s->section]->flags & SHF_EXECINSTR))
return; /* we are only interested in the text stuff */
numlinestabs++;
el = (struct linelist *)nasm_malloc(sizeof(struct linelist));
el->info.offset = s->offset;
el->info.section = s->section;
el->info.name = s->name;
el->line = currentline;
el->filename = stabs_filename;
el->next = 0;
if (stabslines) {
stabslines->last->next = el;
stabslines->last = el;
} else {
stabslines = el;
stabslines->last = el;
}
}
}
debug_immcall = 0;
}
#define WRITE_STAB(p,n_strx,n_type,n_other,n_desc,n_value) \
do {\
WRITELONG(p,n_strx); \
WRITECHAR(p,n_type); \
WRITECHAR(p,n_other); \
WRITESHORT(p,n_desc); \
WRITELONG(p,n_value); \
} while (0)
/* for creating the .stab , .stabstr and .rel.stab sections in memory */
void stabs32_generate(void)
{
int i, numfiles, strsize, numstabs = 0, currfile, mainfileindex;
uint8_t *sbuf, *ssbuf, *rbuf, *sptr, *rptr;
char **allfiles;
int *fileidx;
struct linelist *ptr;
ptr = stabslines;
allfiles = (char **)nasm_malloc(numlinestabs * sizeof(char *));
for (i = 0; i < numlinestabs; i++)
allfiles[i] = 0;
numfiles = 0;
while (ptr) {
if (numfiles == 0) {
allfiles[0] = ptr->filename;
numfiles++;
} else {
for (i = 0; i < numfiles; i++) {
if (!strcmp(allfiles[i], ptr->filename))
break;
}
if (i >= numfiles) {
allfiles[i] = ptr->filename;
numfiles++;
}
}
ptr = ptr->next;
}
strsize = 1;
fileidx = (int *)nasm_malloc(numfiles * sizeof(int));
for (i = 0; i < numfiles; i++) {
fileidx[i] = strsize;
strsize += strlen(allfiles[i]) + 1;
}
mainfileindex = 0;
for (i = 0; i < numfiles; i++) {
if (!strcmp(allfiles[i], elf_module)) {
mainfileindex = i;
break;
}
}
/* worst case size of the stab buffer would be:
the sourcefiles changes each line, which would mean 1 SOL, 1 SYMLIN per line
*/
sbuf =
(uint8_t *)nasm_malloc((numlinestabs * 2 + 3) *
sizeof(struct stabentry));
ssbuf = (uint8_t *)nasm_malloc(strsize);
rbuf = (uint8_t *)nasm_malloc(numlinestabs * 8 * (2 + 3));
rptr = rbuf;
for (i = 0; i < numfiles; i++) {
strcpy((char *)ssbuf + fileidx[i], allfiles[i]);
}
ssbuf[0] = 0;
stabstrlen = strsize; /* set global variable for length of stab strings */
sptr = sbuf;
ptr = stabslines;
numstabs = 0;
if (ptr) {
/* this is the first stab, its strx points to the filename of the
the source-file, the n_desc field should be set to the number
of remaining stabs
*/
WRITE_STAB(sptr, fileidx[0], 0, 0, 0, strlen(allfiles[0] + 12));
/* this is the stab for the main source file */
WRITE_STAB(sptr, fileidx[mainfileindex], N_SO, 0, 0, 0);
/* relocation table entry */
/* Since the symbol table has two entries before */
/* the section symbols, the index in the info.section */
/* member must be adjusted by adding 2 */
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
numstabs++;
currfile = mainfileindex;
}
while (ptr) {
if (strcmp(allfiles[currfile], ptr->filename)) {
/* oops file has changed... */
for (i = 0; i < numfiles; i++)
if (!strcmp(allfiles[i], ptr->filename))
break;
currfile = i;
WRITE_STAB(sptr, fileidx[currfile], N_SOL, 0, 0,
ptr->info.offset);
numstabs++;
/* relocation table entry */
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
}
WRITE_STAB(sptr, 0, N_SLINE, 0, ptr->line, ptr->info.offset);
numstabs++;
/* relocation table entry */
WRITELONG(rptr, (sptr - sbuf) - 4);
WRITELONG(rptr, ((ptr->info.section + 2) << 8) | R_386_32);
ptr = ptr->next;
}
((struct stabentry *)sbuf)->n_desc = numstabs;
nasm_free(allfiles);
nasm_free(fileidx);
stablen = (sptr - sbuf);
stabrellen = (rptr - rbuf);
stabrelbuf = rbuf;
stabbuf = sbuf;
stabstrbuf = ssbuf;
}
void stabs32_cleanup(void)
{
struct linelist *ptr, *del;
if (!stabslines)
return;
ptr = stabslines;
while (ptr) {
del = ptr;
ptr = ptr->next;
nasm_free(del);
}
if (stabbuf)
nasm_free(stabbuf);
if (stabrelbuf)
nasm_free(stabrelbuf);
if (stabstrbuf)
nasm_free(stabstrbuf);
}
/* dwarf routines */
void dwarf32_linenum(const char *filename, int32_t linenumber, int32_t segto)
{
(void)segto;
dwarf32_findfile(filename);
debug_immcall = 1;
currentline = linenumber;
}
/* called from elf_out with type == TY_DEBUGSYMLIN */
void dwarf32_output(int type, void *param)
{
int ln, aa, inx, maxln, soc;
struct symlininfo *s;
struct SAA *plinep;
(void)type;
s = (struct symlininfo *)param;
/* line number info is only gathered for executable sections */
if (!(sects[s->section]->flags & SHF_EXECINSTR))
return;
/* Check if section index has changed */
if (!(dwarf_csect && (dwarf_csect->section) == (s->section)))
{
dwarf32_findsect(s->section);
}
/* do nothing unless line or file has changed */
if (debug_immcall)
{
ln = currentline - dwarf_csect->line;
aa = s->offset - dwarf_csect->offset;
inx = dwarf_clist->line;
plinep = dwarf_csect->psaa;
/* check for file change */
if (!(inx == dwarf_csect->file))
{
saa_write8(plinep,DW_LNS_set_file);
saa_write8(plinep,inx);
dwarf_csect->file = inx;
}
/* check for line change */
if (ln)
{
/* test if in range of special op code */
maxln = line_base + line_range;
soc = (ln - line_base) + (line_range * aa) + opcode_base;
if (ln >= line_base && ln < maxln && soc < 256)
{
saa_write8(plinep,soc);
}
else
{
if (ln)
{
saa_write8(plinep,DW_LNS_advance_line);
saa_wleb128s(plinep,ln);
}
if (aa)
{
saa_write8(plinep,DW_LNS_advance_pc);
saa_wleb128u(plinep,aa);
}
}
dwarf_csect->line = currentline;
dwarf_csect->offset = s->offset;
}
/* show change handled */
debug_immcall = 0;
}
}
void dwarf32_generate(void)
{
static const char nasm_signature[] = "NASM " NASM_VER;
uint8_t *pbuf;
int indx;
struct linelist *ftentry;
struct SAA *paranges, *ppubnames, *pinfo, *pabbrev, *plines, *plinep;
struct SAA *parangesrel, *plinesrel, *pinforel;
struct sectlist *psect;
size_t saalen, linepoff, totlen, highaddr;
/* write epilogues for each line program range */
/* and build aranges section */
paranges = saa_init(1L);
parangesrel = saa_init(1L);
saa_write16(paranges,2); /* dwarf version */
saa_write32(parangesrel, paranges->datalen+4);
saa_write32(parangesrel, (dwarf_infosym << 8) + R_386_32); /* reloc to info */
saa_write32(parangesrel, 0);
saa_write32(paranges,0); /* offset into info */
saa_write8(paranges,4); /* pointer size */
saa_write8(paranges,0); /* not segmented */
saa_write32(paranges,0); /* padding */
/* iterate though sectlist entries */
psect = dwarf_fsect;
totlen = 0;
highaddr = 0;
for (indx = 0; indx < dwarf_nsections; indx++)
{
plinep = psect->psaa;
/* Line Number Program Epilogue */
saa_write8(plinep,2); /* std op 2 */
saa_write8(plinep,(sects[psect->section]->len)-psect->offset);
saa_write8(plinep,DW_LNS_extended_op);
saa_write8(plinep,1); /* operand length */
saa_write8(plinep,DW_LNE_end_sequence);
totlen += plinep->datalen;
/* range table relocation entry */
saa_write32(parangesrel, paranges->datalen + 4);
saa_write32(parangesrel, ((uint32_t) (psect->section + 2) << 8) + R_386_32);
saa_write32(parangesrel, (uint32_t) 0);
/* range table entry */
saa_write32(paranges,0x0000); /* range start */
saa_write32(paranges,sects[psect->section]->len); /* range length */
highaddr += sects[psect->section]->len;
/* done with this entry */
psect = psect->next;
}
saa_write32(paranges,0); /* null address */
saa_write32(paranges,0); /* null length */
saalen = paranges->datalen;
arangeslen = saalen + 4;
arangesbuf = pbuf = nasm_malloc(arangeslen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(paranges, pbuf, saalen);
saa_free(paranges);
/* build rela.aranges section */
arangesrellen = saalen = parangesrel->datalen;
arangesrelbuf = pbuf = nasm_malloc(arangesrellen);
saa_rnbytes(parangesrel, pbuf, saalen);
saa_free(parangesrel);
/* build pubnames section */
ppubnames = saa_init(1L);
saa_write16(ppubnames,3); /* dwarf version */
saa_write32(ppubnames,0); /* offset into info */
saa_write32(ppubnames,0); /* space used in info */
saa_write32(ppubnames,0); /* end of list */
saalen = ppubnames->datalen;
pubnameslen = saalen + 4;
pubnamesbuf = pbuf = nasm_malloc(pubnameslen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(ppubnames, pbuf, saalen);
saa_free(ppubnames);
/* build info section */
pinfo = saa_init(1L);
pinforel = saa_init(1L);
saa_write16(pinfo,2); /* dwarf version */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, (dwarf_abbrevsym << 8) + R_386_32); /* reloc to abbrev */
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* offset into abbrev */
saa_write8(pinfo,4); /* pointer size */
saa_write8(pinfo,1); /* abbrviation number LEB128u */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_low_pc */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,highaddr); /* DW_AT_high_pc */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, (dwarf_linesym << 8) + R_386_32); /* reloc to line */
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_stmt_list */
saa_wbytes(pinfo, elf_module, strlen(elf_module)+1);
saa_wbytes(pinfo, nasm_signature, strlen(nasm_signature)+1);
saa_write16(pinfo,DW_LANG_Mips_Assembler);
saa_write8(pinfo,2); /* abbrviation number LEB128u */
saa_write32(pinforel, pinfo->datalen + 4);
saa_write32(pinforel, ((dwarf_fsect->section + 2) << 8) + R_386_32);
saa_write32(pinforel, 0);
saa_write32(pinfo,0); /* DW_AT_low_pc */
saa_write32(pinfo,0); /* DW_AT_frame_base */
saa_write8(pinfo,0); /* end of entries */
saalen = pinfo->datalen;
infolen = saalen + 4;
infobuf = pbuf = nasm_malloc(infolen);
WRITELONG(pbuf,saalen); /* initial length */
saa_rnbytes(pinfo, pbuf, saalen);
saa_free(pinfo);
/* build rela.info section */
inforellen = saalen = pinforel->datalen;
inforelbuf = pbuf = nasm_malloc(inforellen);
saa_rnbytes(pinforel, pbuf, saalen);
saa_free(pinforel);
/* build abbrev section */
pabbrev = saa_init(1L);
saa_write8(pabbrev,1); /* entry number LEB128u */
saa_write8(pabbrev,DW_TAG_compile_unit); /* tag LEB128u */
saa_write8(pabbrev,1); /* has children */
/* the following attributes and forms are all LEB128u values */
saa_write8(pabbrev,DW_AT_low_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_high_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_stmt_list);
saa_write8(pabbrev,DW_FORM_data4);
saa_write8(pabbrev,DW_AT_name);
saa_write8(pabbrev,DW_FORM_string);
saa_write8(pabbrev,DW_AT_producer);
saa_write8(pabbrev,DW_FORM_string);
saa_write8(pabbrev,DW_AT_language);
saa_write8(pabbrev,DW_FORM_data2);
saa_write16(pabbrev,0); /* end of entry */
/* LEB128u usage same as above */
saa_write8(pabbrev,2); /* entry number */
saa_write8(pabbrev,DW_TAG_subprogram);
saa_write8(pabbrev,0); /* no children */
saa_write8(pabbrev,DW_AT_low_pc);
saa_write8(pabbrev,DW_FORM_addr);
saa_write8(pabbrev,DW_AT_frame_base);
saa_write8(pabbrev,DW_FORM_data4);
saa_write16(pabbrev,0); /* end of entry */
abbrevlen = saalen = pabbrev->datalen;
abbrevbuf = pbuf = nasm_malloc(saalen);
saa_rnbytes(pabbrev, pbuf, saalen);
saa_free(pabbrev);
/* build line section */
/* prolog */
plines = saa_init(1L);
saa_write8(plines,1); /* Minimum Instruction Length */
saa_write8(plines,1); /* Initial value of 'is_stmt' */
saa_write8(plines,line_base); /* Line Base */
saa_write8(plines,line_range); /* Line Range */
saa_write8(plines,opcode_base); /* Opcode Base */
/* standard opcode lengths (# of LEB128u operands) */
saa_write8(plines,0); /* Std opcode 1 length */
saa_write8(plines,1); /* Std opcode 2 length */
saa_write8(plines,1); /* Std opcode 3 length */
saa_write8(plines,1); /* Std opcode 4 length */
saa_write8(plines,1); /* Std opcode 5 length */
saa_write8(plines,0); /* Std opcode 6 length */
saa_write8(plines,0); /* Std opcode 7 length */
saa_write8(plines,0); /* Std opcode 8 length */
saa_write8(plines,1); /* Std opcode 9 length */
saa_write8(plines,0); /* Std opcode 10 length */
saa_write8(plines,0); /* Std opcode 11 length */
saa_write8(plines,1); /* Std opcode 12 length */
/* Directory Table */
saa_write8(plines,0); /* End of table */
/* File Name Table */
ftentry = dwarf_flist;
for (indx = 0;indx<dwarf_numfiles;indx++)
{
saa_wbytes(plines, ftentry->filename, (int32_t)(strlen(ftentry->filename) + 1));
saa_write8(plines,0); /* directory LEB128u */
saa_write8(plines,0); /* time LEB128u */
saa_write8(plines,0); /* size LEB128u */
ftentry = ftentry->next;
}
saa_write8(plines,0); /* End of table */
linepoff = plines->datalen;
linelen = linepoff + totlen + 10;
linebuf = pbuf = nasm_malloc(linelen);
WRITELONG(pbuf,linelen-4); /* initial length */
WRITESHORT(pbuf,3); /* dwarf version */
WRITELONG(pbuf,linepoff); /* offset to line number program */
/* write line header */
saalen = linepoff;
saa_rnbytes(plines, pbuf, saalen); /* read a given no. of bytes */
pbuf += linepoff;
saa_free(plines);
/* concatonate line program ranges */
linepoff += 13;
plinesrel = saa_init(1L);
psect = dwarf_fsect;
for (indx = 0; indx < dwarf_nsections; indx++)
{
saa_write32(plinesrel, linepoff);
saa_write32(plinesrel, ((uint32_t) (psect->section + 2) << 8) + R_386_32);
saa_write32(plinesrel, (uint32_t) 0);
plinep = psect->psaa;
saalen = plinep->datalen;
saa_rnbytes(plinep, pbuf, saalen);
pbuf += saalen;
linepoff += saalen;
saa_free(plinep);
/* done with this entry */
psect = psect->next;
}
/* build rela.lines section */
linerellen =saalen = plinesrel->datalen;
linerelbuf = pbuf = nasm_malloc(linerellen);
saa_rnbytes(plinesrel, pbuf, saalen);
saa_free(plinesrel);
/* build frame section */
framelen = 4;
framebuf = pbuf = nasm_malloc(framelen);
WRITELONG(pbuf,framelen-4); /* initial length */
/* build loc section */
loclen = 16;
locbuf = pbuf = nasm_malloc(loclen);
WRITELONG(pbuf,0); /* null beginning offset */
WRITELONG(pbuf,0); /* null ending offset */
}
void dwarf32_cleanup(void)
{
if (arangesbuf)
nasm_free(arangesbuf);
if (arangesrelbuf)
nasm_free(arangesrelbuf);
if (pubnamesbuf)
nasm_free(pubnamesbuf);
if (infobuf)
nasm_free(infobuf);
if (inforelbuf)
nasm_free(inforelbuf);
if (abbrevbuf)
nasm_free(abbrevbuf);
if (linebuf)
nasm_free(linebuf);
if (linerelbuf)
nasm_free(linerelbuf);
if (framebuf)
nasm_free(framebuf);
if (locbuf)
nasm_free(locbuf);
}
void dwarf32_findfile(const char * fname)
{
int finx;
struct linelist *match;
/* return if fname is current file name */
if (dwarf_clist && !(strcmp(fname, dwarf_clist->filename))) return;
/* search for match */
else
{
match = 0;
if (dwarf_flist)
{
match = dwarf_flist;
for (finx = 0; finx < dwarf_numfiles; finx++)
{
if (!(strcmp(fname, match->filename)))
{
dwarf_clist = match;
return;
}
}
}
/* add file name to end of list */
dwarf_clist = (struct linelist *)nasm_malloc(sizeof(struct linelist));
dwarf_numfiles++;
dwarf_clist->line = dwarf_numfiles;
dwarf_clist->filename = nasm_malloc(strlen(fname) + 1);
strcpy(dwarf_clist->filename,fname);
dwarf_clist->next = 0;
/* if first entry */
if (!dwarf_flist)
{
dwarf_flist = dwarf_elist = dwarf_clist;
dwarf_clist->last = 0;
}
/* chain to previous entry */
else
{
dwarf_elist->next = dwarf_clist;
dwarf_elist = dwarf_clist;
}
}
}
/* */
void dwarf32_findsect(const int index)
{
int sinx;
struct sectlist *match;
struct SAA *plinep;
/* return if index is current section index */
if (dwarf_csect && (dwarf_csect->section == index))
{
return;
}
/* search for match */
else
{
match = 0;
if (dwarf_fsect)
{
match = dwarf_fsect;
for (sinx = 0; sinx < dwarf_nsections; sinx++)
{
if ((match->section == index))
{
dwarf_csect = match;
return;
}
match = match->next;
}
}
/* add entry to end of list */
dwarf_csect = (struct sectlist *)nasm_malloc(sizeof(struct sectlist));
dwarf_nsections++;
dwarf_csect->psaa = plinep = saa_init(1L);
dwarf_csect->line = 1;
dwarf_csect->offset = 0;
dwarf_csect->file = 1;
dwarf_csect->section = index;
dwarf_csect->next = 0;
/* set relocatable address at start of line program */
saa_write8(plinep,DW_LNS_extended_op);
saa_write8(plinep,5); /* operand length */
saa_write8(plinep,DW_LNE_set_address);
saa_write32(plinep,0); /* Start Address */
/* if first entry */
if (!dwarf_fsect)
{
dwarf_fsect = dwarf_esect = dwarf_csect;
dwarf_csect->last = 0;
}
/* chain to previous entry */
else
{
dwarf_esect->next = dwarf_csect;
dwarf_esect = dwarf_csect;
}
}
}
#endif /* OF_ELF */
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