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nasm/output/outrdf2.c
H. Peter Anvin fd52c277dd output: Allow OUT_ADDRESS with a negative size to mean signed relocation 
This only matters for ELF64/ELFx32, at least for now.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-11-26 18:12:39 -08:00

800 lines
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/* ----------------------------------------------------------------------- *
*
* Copyright 1996-2013 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following
* conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*
* ----------------------------------------------------------------------- */
/*
* outrdf2.c output routines for the Netwide Assembler to produce
* RDOFF version 2 format object files, which Julian originally
* planned to use it in his MOSCOW operating system.
*/
#include "compiler.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <inttypes.h>
#include "nasm.h"
#include "nasmlib.h"
#include "saa.h"
#include "output/outform.h"
#include "output/outlib.h"
/* VERBOSE_WARNINGS: define this to add some extra warnings... */
#define VERBOSE_WARNINGS
#ifdef OF_RDF2
#include "rdoff/rdoff.h"
/* This signature is written to start of RDOFF files */
static const char *RDOFF2Id = RDOFF2_SIGNATURE;
/* Note that whenever a segment is referred to in the RDOFF file, its number
* is always half of the segment number that NASM uses to refer to it; this
* is because NASM only allocates even numbered segments, so as to not
* waste any of the 16 bits of segment number written to the file - this
* allows up to 65533 external labels to be defined; otherwise it would be
* 32764. */
#define COUNT_SEGTYPES 9
static char *segmenttypes[COUNT_SEGTYPES] = {
"null", "text", "code", "data",
"comment", "lcomment", "pcomment",
"symdebug", "linedebug"
};
static int segmenttypenumbers[COUNT_SEGTYPES] = {
0, 1, 1, 2, 3, 4, 5, 6, 7
};
/* code for managing buffers needed to separate code and data into individual
* sections until they are ready to be written to the file.
* We'd better hope that it all fits in memory else we're buggered... */
#define BUF_BLOCK_LEN 4088 /* selected to match page size (4096)
* on 80x86 machines for efficiency */
/***********************************************************************
* Actual code to deal with RDOFF2 ouput format begins here...
*/
/* global variables set during the initialisation phase */
static struct SAA *seg[RDF_MAXSEGS]; /* seg 0 = code, seg 1 = data */
static struct SAA *header; /* relocation/import/export records */
static struct seginfo {
char *segname;
int segnumber;
uint16_t segtype;
uint16_t segreserved;
int32_t seglength;
} segments[RDF_MAXSEGS];
static int nsegments;
static int32_t bsslength;
static int32_t headerlength;
static void rdf2_init(void)
{
int segtext, segdata, segbss;
maxbits = 64;
/* set up the initial segments */
segments[0].segname = ".text";
segments[0].segnumber = 0;
segments[0].segtype = 1;
segments[0].segreserved = 0;
segments[0].seglength = 0;
segments[1].segname = ".data";
segments[1].segnumber = 1;
segments[1].segtype = 2;
segments[1].segreserved = 0;
segments[1].seglength = 0;
segments[2].segname = ".bss";
segments[2].segnumber = 2;
segments[2].segtype = 0xFFFF; /* reserved - should never be produced */
segments[2].segreserved = 0;
segments[2].seglength = 0;
nsegments = 3;
seg[0] = saa_init(1L);
seg[1] = saa_init(1L);
seg[2] = NULL; /* special case! */
header = saa_init(1L);
segtext = seg_alloc();
segdata = seg_alloc();
segbss = seg_alloc();
if (segtext != 0 || segdata != 2 || segbss != 4)
nasm_error(ERR_PANIC,
"rdf segment numbers not allocated as expected (%d,%d,%d)",
segtext, segdata, segbss);
bsslength = 0;
headerlength = 0;
}
static int32_t rdf2_section_names(char *name, int pass, int *bits)
{
int i;
bool err;
char *p, *q;
int code = -1;
int reserved = 0;
(void)pass;
/*
* Default is 32 bits, in the text segment.
*/
if (!name) {
*bits = 32;
return 0;
}
/* look for segment type code following segment name */
p = name;
while (*p && !nasm_isspace(*p))
p++;
if (*p) { /* we're now in whitespace */
*p++ = '\0';
while (*p && nasm_isspace(80))
*p++ = '\0';
}
if (*p) { /* we're now in an attribute value */
/*
* see if we have an optional ',number' following the type code
*/
if ((q = strchr(p, ','))) {
*q++ = '\0';
reserved = readnum(q, &err);
if (err) {
nasm_error(ERR_NONFATAL,
"value following comma must be numeric");
reserved = 0;
}
}
/*
* check it against the text strings in segmenttypes
*/
for (i = 0; i < COUNT_SEGTYPES; i++)
if (!nasm_stricmp(p, segmenttypes[i])) {
code = segmenttypenumbers[i];
break;
}
if (code == -1) { /* didn't find anything */
code = readnum(p, &err);
if (err) {
nasm_error(ERR_NONFATAL, "unrecognised RDF segment type (%s)",
p);
code = 3;
}
}
}
for (i = 0; i < nsegments; i++) {
if (!strcmp(name, segments[i].segname)) {
if (code != -1 || reserved != 0)
nasm_error(ERR_NONFATAL, "segment attributes specified on"
" redeclaration of segment");
return segments[i].segnumber * 2;
}
}
/* declaring a new segment! */
if (code == -1) {
nasm_error(ERR_NONFATAL, "new segment declared without type code");
code = 3;
}
if (nsegments == RDF_MAXSEGS) {
nasm_error(ERR_FATAL, "reached compiled-in maximum segment limit (%d)",
RDF_MAXSEGS);
return NO_SEG;
}
segments[nsegments].segname = nasm_strdup(name);
i = seg_alloc();
if (i % 2 != 0)
nasm_error(ERR_PANIC, "seg_alloc() returned odd number");
segments[nsegments].segnumber = i >> 1;
segments[nsegments].segtype = code;
segments[nsegments].segreserved = reserved;
segments[nsegments].seglength = 0;
seg[nsegments] = saa_init(1L);
return i;
}
/*
* Write relocation record
*/
static void write_reloc_rec(struct RelocRec *r)
{
char buf[4], *b;
if (r->refseg != (uint16_t) NO_SEG && (r->refseg & 1)) /* segment base ref */
r->type = RDFREC_SEGRELOC;
r->refseg >>= 1; /* adjust segment nos to RDF rather than NASM */
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
saa_wbytes(header, &r->segment, 1);
b = buf;
WRITELONG(b, r->offset);
saa_wbytes(header, buf, 4);
saa_wbytes(header, &r->length, 1);
b = buf;
WRITESHORT(b, r->refseg);
saa_wbytes(header, buf, 2);
headerlength += r->reclen + 2;
}
/*
* Write export record
*/
static void write_export_rec(struct ExportRec *r)
{
char buf[4], *b;
r->segment >>= 1;
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
saa_wbytes(header, &r->flags, 1);
saa_wbytes(header, &r->segment, 1);
b = buf;
WRITELONG(b, r->offset);
saa_wbytes(header, buf, 4);
saa_wbytes(header, r->label, strlen(r->label) + 1);
headerlength += r->reclen + 2;
}
static void write_import_rec(struct ImportRec *r)
{
char buf[4], *b;
r->segment >>= 1;
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
saa_wbytes(header, &r->flags, 1);
b = buf;
WRITESHORT(b, r->segment);
saa_wbytes(header, buf, 2);
saa_wbytes(header, r->label, strlen(r->label) + 1);
headerlength += r->reclen + 2;
}
/*
* Write BSS record
*/
static void write_bss_rec(struct BSSRec *r)
{
char buf[4], *b;
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
b = buf;
WRITELONG(b, r->amount);
saa_wbytes(header, buf, 4);
headerlength += r->reclen + 2;
}
/*
* Write common variable record
*/
static void write_common_rec(struct CommonRec *r)
{
char buf[4], *b;
r->segment >>= 1;
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
b = buf;
WRITESHORT(b, r->segment);
saa_wbytes(header, buf, 2);
b = buf;
WRITELONG(b, r->size);
saa_wbytes(header, buf, 4);
b = buf;
WRITESHORT(b, r->align);
saa_wbytes(header, buf, 2);
saa_wbytes(header, r->label, strlen(r->label) + 1);
headerlength += r->reclen + 2;
}
/*
* Write library record
*/
static void write_dll_rec(struct DLLRec *r)
{
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
saa_wbytes(header, r->libname, strlen(r->libname) + 1);
headerlength += r->reclen + 2;
}
/*
* Write module name record
*/
static void write_modname_rec(struct ModRec *r)
{
saa_wbytes(header, &r->type, 1);
saa_wbytes(header, &r->reclen, 1);
saa_wbytes(header, r->modname, strlen(r->modname) + 1);
headerlength += r->reclen + 2;
}
/*
* Handle export, import and common records.
*/
static void rdf2_deflabel(char *name, int32_t segment, int64_t offset,
int is_global, char *special)
{
struct ExportRec r;
struct ImportRec ri;
struct CommonRec ci;
static int farsym = 0;
static int i;
char symflags = 0;
int len;
/* Check if the label length is OK */
if ((len = strlen(name)) >= EXIM_LABEL_MAX) {
nasm_error(ERR_NONFATAL, "label size exceeds %d bytes", EXIM_LABEL_MAX);
return;
}
if (!len) {
nasm_error(ERR_NONFATAL, "zero-length label");
return;
}
if (is_global == 2) {
/* Common variable */
ci.type = RDFREC_COMMON;
ci.size = offset;
ci.segment = segment;
strcpy(ci.label, name);
ci.reclen = 9 + len;
ci.align = 0;
/*
* 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;
ci.align = readnum(special, &err);
if (err)
nasm_error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" valid number", special);
else if ((ci.align | (ci.align - 1)) != 2 * ci.align - 1)
nasm_error(ERR_NONFATAL, "alignment constraint `%s' is not a"
" power of two", special);
}
write_common_rec(&ci);
}
/* We don't care about local labels or fix-up hints */
if (is_global != 1)
return;
if (special) {
while (*special == ' ' || *special == '\t')
special++;
if (!nasm_strnicmp(special, "export", 6)) {
special += 6;
symflags |= SYM_GLOBAL;
} else if (!nasm_strnicmp(special, "import", 6)) {
special += 6;
symflags |= SYM_IMPORT;
}
if (*special) {
while (nasm_isspace(*special))
special++;
if (!nasm_stricmp(special, "far")) {
farsym = 1;
} else if (!nasm_stricmp(special, "near")) {
farsym = 0;
} else if (!nasm_stricmp(special, "proc") ||
!nasm_stricmp(special, "function")) {
symflags |= SYM_FUNCTION;
} else if (!nasm_stricmp(special, "data") ||
!nasm_stricmp(special, "object")) {
symflags |= SYM_DATA;
} else
nasm_error(ERR_NONFATAL, "unrecognised symbol type `%s'",
special);
}
}
if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
nasm_error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
return;
}
for (i = 0; i < nsegments; i++) {
if (segments[i].segnumber == segment >> 1)
break;
}
if (i >= nsegments) { /* EXTERN declaration */
ri.type = farsym ? RDFREC_FARIMPORT : RDFREC_IMPORT;
if (symflags & SYM_GLOBAL)
nasm_error(ERR_NONFATAL,
"symbol type conflict - EXTERN cannot be EXPORT");
ri.flags = symflags;
ri.segment = segment;
strcpy(ri.label, name);
ri.reclen = 4 + len;
write_import_rec(&ri);
} else if (is_global) {
r.type = RDFREC_GLOBAL; /* GLOBAL declaration */
if (symflags & SYM_IMPORT)
nasm_error(ERR_NONFATAL,
"symbol type conflict - GLOBAL cannot be IMPORT");
r.flags = symflags;
r.segment = segment;
r.offset = offset;
strcpy(r.label, name);
r.reclen = 7 + len;
write_export_rec(&r);
}
}
static void membufwrite(int segment, const void *data, int bytes)
{
int i;
char buf[4], *b;
for (i = 0; i < nsegments; i++) {
if (segments[i].segnumber == segment)
break;
}
if (i == nsegments)
nasm_error(ERR_PANIC, "can't find segment %d", segment);
if (bytes < 0) {
b = buf;
if (bytes == -2)
WRITESHORT(b, *(int16_t *)data);
else
WRITELONG(b, *(int32_t *)data);
data = buf;
bytes = -bytes;
}
segments[i].seglength += bytes;
saa_wbytes(seg[i], data, bytes);
}
static int getsegmentlength(int segment)
{
int i;
for (i = 0; i < nsegments; i++) {
if (segments[i].segnumber == segment)
break;
}
if (i == nsegments)
nasm_error(ERR_PANIC, "can't find segment %d", segment);
return segments[i].seglength;
}
static void rdf2_out(int32_t segto, const void *data,
enum out_type type, uint64_t size,
int32_t segment, int32_t wrt)
{
struct RelocRec rr;
uint8_t databuf[8], *pd;
int seg;
if (segto == NO_SEG) {
if (type != OUT_RESERVE)
nasm_error(ERR_NONFATAL,
"attempt to assemble code in ABSOLUTE space");
return;
}
segto >>= 1; /* convert NASM segment no to RDF number */
for (seg = 0; seg < nsegments; seg++) {
if (segments[seg].segnumber == segto)
break;
}
if (seg >= nsegments) {
nasm_error(ERR_NONFATAL,
"specified segment not supported by rdf output format");
return;
}
if (wrt != NO_SEG) {
wrt = NO_SEG; /* continue to do _something_ */
nasm_error(ERR_NONFATAL, "WRT not supported by rdf output format");
}
if (segto == 2 && type != OUT_RESERVE) {
nasm_error(ERR_NONFATAL, "BSS segments may not be initialized");
/* just reserve the space for now... */
if (type == OUT_REL2ADR)
size = 2;
else
size = 4;
type = OUT_RESERVE;
}
if (type == OUT_RESERVE) {
if (segto == 2) /* BSS segment space reserverd */
bsslength += size;
else
while (size--)
membufwrite(segto, databuf, 1);
} else if (type == OUT_RAWDATA) {
if (segment != NO_SEG)
nasm_error(ERR_PANIC, "OUT_RAWDATA with other than NO_SEG");
membufwrite(segto, data, size);
} else if (type == OUT_ADDRESS) {
int asize = abs(size);
/* if segment == NO_SEG then we are writing an address of an
object within the same segment - do not produce reloc rec. */
/* FIXME - is this behaviour sane? at first glance it doesn't
appear to be. Must test this thoroughly...! */
if (segment != NO_SEG) {
/* it's an address, so we must write a relocation record */
rr.type = RDFREC_RELOC; /* type signature */
rr.reclen = 8;
rr.segment = segto; /* segment we're currently in */
rr.offset = getsegmentlength(segto); /* current offset */
rr.length = asize; /* length of reference */
rr.refseg = segment; /* segment referred to */
write_reloc_rec(&rr);
}
pd = databuf; /* convert address to little-endian */
WRITEADDR(pd, *(int64_t *)data, asize);
membufwrite(segto, databuf, asize);
} else if (type == OUT_REL2ADR) {
if (segment == segto)
nasm_error(ERR_PANIC, "intra-segment OUT_REL2ADR");
rr.reclen = 8;
rr.offset = getsegmentlength(segto); /* current offset */
rr.length = 2; /* length of reference */
rr.refseg = segment; /* segment referred to (will be >>1'd) */
if (segment != NO_SEG && segment % 2) {
rr.type = RDFREC_SEGRELOC;
rr.segment = segto; /* memory base refs *aren't ever* relative! */
write_reloc_rec(&rr);
/* what do we put in the code? Simply the data. This should almost
* always be zero, unless someone's doing segment arithmetic...
*/
rr.offset = *(int64_t *)data;
} else {
rr.type = RDFREC_RELOC; /* type signature */
rr.segment = segto + 64; /* segment we're currently in + rel flag */
write_reloc_rec(&rr);
/* work out what to put in the code: offset of the end of this operand,
* subtracted from any data specified, so that loader can just add
* address of imported symbol onto it to get address relative to end of
* instruction: import_address + data(offset) - end_of_instrn */
rr.offset = *(int32_t *)data - (rr.offset + size);
}
membufwrite(segto, &rr.offset, -2);
} else if (type == OUT_REL4ADR) {
if ((segment == segto) && (globalbits != 64))
nasm_error(ERR_PANIC, "intra-segment OUT_REL4ADR");
if (segment != NO_SEG && segment % 2) {
nasm_error(ERR_PANIC, "erm... 4 byte segment base ref?");
}
rr.type = RDFREC_RELOC; /* type signature */
rr.segment = segto + 64; /* segment we're currently in + rel tag */
rr.offset = getsegmentlength(segto); /* current offset */
rr.length = 4; /* length of reference */
rr.refseg = segment; /* segment referred to */
rr.reclen = 8;
write_reloc_rec(&rr);
rr.offset = *(int64_t *)data - (rr.offset + size);
membufwrite(segto, &rr.offset, -4);
}
}
static void rdf2_cleanup(int debuginfo)
{
int32_t l;
struct BSSRec bs;
int i;
(void)debuginfo;
/* should write imported & exported symbol declarations to header here */
/* generate the output file... */
fwrite(RDOFF2Id, 6, 1, ofile); /* file type magic number */
if (bsslength != 0) { /* reserve BSS */
bs.type = RDFREC_BSS;
bs.amount = bsslength;
bs.reclen = 4;
write_bss_rec(&bs);
}
/*
* calculate overall length of the output object
*/
l = headerlength + 4;
for (i = 0; i < nsegments; i++) {
if (i == 2)
continue; /* skip BSS segment */
l += 10 + segments[i].seglength;
}
l += 10; /* null segment */
fwriteint32_t(l, ofile);
fwriteint32_t(headerlength, ofile);
saa_fpwrite(header, ofile); /* dump header */
saa_free(header);
for (i = 0; i < nsegments; i++) {
if (i == 2)
continue;
fwriteint16_t(segments[i].segtype, ofile);
fwriteint16_t(segments[i].segnumber, ofile);
fwriteint16_t(segments[i].segreserved, ofile);
fwriteint32_t(segments[i].seglength, ofile);
saa_fpwrite(seg[i], ofile);
saa_free(seg[i]);
}
/* null segment - write 10 bytes of zero */
fwriteint32_t(0, ofile);
fwriteint32_t(0, ofile);
fwriteint16_t(0, ofile);
}
static int32_t rdf2_segbase(int32_t segment)
{
return segment;
}
/*
* Handle RDOFF2 specific directives
*/
static int rdf2_directive(enum directives directive, char *value, int pass)
{
size_t n;
switch (directive) {
case D_LIBRARY:
n = strlen(value);
if (n >= MODLIB_NAME_MAX) {
nasm_error(ERR_NONFATAL, "name size exceeds %d bytes", MODLIB_NAME_MAX);
return 1;
}
if (pass == 1) {
struct DLLRec r;
r.type = RDFREC_DLL;
r.reclen = n + 1;
strcpy(r.libname, value);
write_dll_rec(&r);
}
return 1;
case D_MODULE:
if ((n = strlen(value)) >= MODLIB_NAME_MAX) {
nasm_error(ERR_NONFATAL, "name size exceeds %d bytes", MODLIB_NAME_MAX);
return 1;
}
if (pass == 1) {
struct ModRec r;
r.type = RDFREC_MODNAME;
r.reclen = n + 1;
strcpy(r.modname, value);
write_modname_rec(&r);
}
return 1;
default:
return 0;
}
}
static void rdf2_filename(char *inname, char *outname)
{
standard_extension(inname, outname, ".rdf");
}
extern macros_t rdf2_stdmac[];
static int rdf2_set_info(enum geninfo type, char **val)
{
(void)type;
(void)val;
return 0;
}
struct ofmt of_rdf2 = {
"Relocatable Dynamic Object File Format v2.0",
"rdf",
0,
null_debug_arr,
&null_debug_form,
rdf2_stdmac,
rdf2_init,
rdf2_set_info,
rdf2_out,
rdf2_deflabel,
rdf2_section_names,
null_sectalign,
rdf2_segbase,
rdf2_directive,
rdf2_filename,
rdf2_cleanup
};
#endif /* OF_RDF2 */
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