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Diffstat (limited to 'vere/ext/nasm/output/outaout.c')
-rw-r--r--vere/ext/nasm/output/outaout.c923
1 files changed, 923 insertions, 0 deletions
diff --git a/vere/ext/nasm/output/outaout.c b/vere/ext/nasm/output/outaout.c
new file mode 100644
index 0000000..c59c789
--- /dev/null
+++ b/vere/ext/nasm/output/outaout.c
@@ -0,0 +1,923 @@
+/* ----------------------------------------------------------------------- *
+ *
+ * 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.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * outaout.c output routines for the Netwide Assembler to produce
+ * Linux a.out object files
+ */
+
+#include "compiler.h"
+
+#include "nctype.h"
+
+#include "nasm.h"
+#include "nasmlib.h"
+#include "error.h"
+#include "saa.h"
+#include "raa.h"
+#include "stdscan.h"
+#include "eval.h"
+#include "outform.h"
+#include "outlib.h"
+
+#if defined OF_AOUT || defined OF_AOUTB
+
+#define RELTYPE_ABSOLUTE 0x00
+#define RELTYPE_RELATIVE 0x01
+#define RELTYPE_GOTPC 0x01 /* no explicit GOTPC in a.out */
+#define RELTYPE_GOTOFF 0x10
+#define RELTYPE_GOT 0x10 /* distinct from GOTOFF bcos sym not sect */
+#define RELTYPE_PLT 0x21
+#define RELTYPE_SYMFLAG 0x08
+
+struct Reloc {
+ struct Reloc *next;
+ int32_t address; /* relative to _start_ of section */
+ int32_t symbol; /* symbol number or -ve section id */
+ int bytes; /* 2 or 4 */
+ int reltype; /* see above */
+};
+
+struct Symbol {
+ int32_t strpos; /* string table position of name */
+ int type; /* symbol type - see flags below */
+ int32_t value; /* address, or COMMON variable size */
+ int32_t size; /* size for data or function exports */
+ int32_t segment; /* back-reference used by gsym_reloc */
+ struct Symbol *next; /* list of globals in each section */
+ struct Symbol *nextfwd; /* list of unresolved-size symbols */
+ char *name; /* for unresolved-size symbols */
+ int32_t symnum; /* index into symbol table */
+};
+
+/*
+ * Section IDs - used in Reloc.symbol when negative, and in
+ * Symbol.type when positive.
+ */
+#define SECT_ABS 2 /* absolute value */
+#define SECT_TEXT 4 /* text section */
+#define SECT_DATA 6 /* data section */
+#define SECT_BSS 8 /* bss section */
+#define SECT_MASK 0xE /* mask out any of the above */
+
+/*
+ * More flags used in Symbol.type.
+ */
+#define SYM_GLOBAL 1 /* it's a global symbol */
+#define SYM_DATA 0x100 /* used for shared libs */
+#define SYM_FUNCTION 0x200 /* used for shared libs */
+#define SYM_WITH_SIZE 0x4000 /* not output; internal only */
+
+/*
+ * Bit more explanation of symbol types: SECT_xxx denotes a local
+ * symbol. SECT_xxx|SYM_GLOBAL denotes a global symbol, defined in
+ * this module. Just SYM_GLOBAL, with zero value, denotes an
+ * external symbol referenced in this module. And just SYM_GLOBAL,
+ * but with a non-zero value, declares a C `common' variable, of
+ * size `value'.
+ */
+
+struct Section {
+ struct SAA *data;
+ uint32_t len, size, nrelocs;
+ int32_t index;
+ struct Reloc *head, **tail;
+ struct Symbol *gsyms, *asym;
+};
+
+static struct Section stext, sdata, sbss;
+
+static struct SAA *syms;
+static uint32_t nsyms;
+
+static struct RAA *bsym;
+
+static struct SAA *strs;
+static uint32_t strslen;
+
+static struct Symbol *fwds;
+
+static int bsd;
+static int is_pic;
+
+static void aout_write(void);
+static void aout_write_relocs(struct Reloc *);
+static void aout_write_syms(void);
+static void aout_sect_write(struct Section *, const uint8_t *,
+ uint32_t);
+static void aout_pad_sections(void);
+static void aout_fixup_relocs(struct Section *);
+
+/*
+ * Special section numbers which are used to define special
+ * symbols, which can be used with WRT to provide PIC relocation
+ * types.
+ */
+static int32_t aout_gotpc_sect, aout_gotoff_sect;
+static int32_t aout_got_sect, aout_plt_sect;
+static int32_t aout_sym_sect;
+
+static void aoutg_init(void)
+{
+ stext.data = saa_init(1L);
+ stext.head = NULL;
+ stext.tail = &stext.head;
+ sdata.data = saa_init(1L);
+ sdata.head = NULL;
+ sdata.tail = &sdata.head;
+ stext.len = stext.size = sdata.len = sdata.size = sbss.len = 0;
+ stext.nrelocs = sdata.nrelocs = 0;
+ stext.gsyms = sdata.gsyms = sbss.gsyms = NULL;
+ stext.index = seg_alloc();
+ sdata.index = seg_alloc();
+ sbss.index = seg_alloc();
+ stext.asym = sdata.asym = sbss.asym = NULL;
+ syms = saa_init((int32_t)sizeof(struct Symbol));
+ nsyms = 0;
+ bsym = raa_init();
+ strs = saa_init(1L);
+ strslen = 0;
+ fwds = NULL;
+}
+
+#ifdef OF_AOUT
+
+static void aout_init(void)
+{
+ bsd = false;
+ aoutg_init();
+
+ aout_gotpc_sect = aout_gotoff_sect = aout_got_sect =
+ aout_plt_sect = aout_sym_sect = NO_SEG;
+}
+
+#endif
+
+#ifdef OF_AOUTB
+
+extern const struct ofmt of_aoutb;
+
+static void aoutb_init(void)
+{
+ bsd = true;
+ aoutg_init();
+
+ is_pic = 0x00; /* may become 0x40 */
+
+ aout_gotpc_sect = seg_alloc();
+ backend_label("..gotpc", aout_gotpc_sect + 1, 0L);
+ aout_gotoff_sect = seg_alloc();
+ backend_label("..gotoff", aout_gotoff_sect + 1, 0L);
+ aout_got_sect = seg_alloc();
+ backend_label("..got", aout_got_sect + 1, 0L);
+ aout_plt_sect = seg_alloc();
+ backend_label("..plt", aout_plt_sect + 1, 0L);
+ aout_sym_sect = seg_alloc();
+ backend_label("..sym", aout_sym_sect + 1, 0L);
+}
+
+#endif
+
+static void aout_cleanup(void)
+{
+ struct Reloc *r;
+
+ aout_pad_sections();
+ aout_fixup_relocs(&stext);
+ aout_fixup_relocs(&sdata);
+ aout_write();
+ saa_free(stext.data);
+ while (stext.head) {
+ r = stext.head;
+ stext.head = stext.head->next;
+ nasm_free(r);
+ }
+ saa_free(sdata.data);
+ while (sdata.head) {
+ r = sdata.head;
+ sdata.head = sdata.head->next;
+ nasm_free(r);
+ }
+ saa_free(syms);
+ raa_free(bsym);
+ saa_free(strs);
+}
+
+static int32_t aout_section_names(char *name, int *bits)
+{
+ /*
+ * Default to 32 bits.
+ */
+ if (!name) {
+ *bits = 32;
+ return stext.index;
+ }
+
+ if (!strcmp(name, ".text"))
+ return stext.index;
+ else if (!strcmp(name, ".data"))
+ return sdata.index;
+ else if (!strcmp(name, ".bss"))
+ return sbss.index;
+ else
+ return NO_SEG;
+}
+
+static void aout_deflabel(char *name, int32_t segment, int64_t offset,
+ int is_global, char *special)
+{
+ int pos = strslen + 4;
+ struct Symbol *sym;
+ int special_used = false;
+
+ if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
+ /*
+ * This is a NASM special symbol. We never allow it into
+ * the a.out 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"))
+ nasm_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;
+
+ p = nasm_skip_spaces(nasm_skip_word(p));
+ stdscan_reset();
+ stdscan_set(p);
+ tokval.t_type = TOKEN_INVALID;
+ e = evaluate(stdscan, NULL, &tokval, NULL, 1, NULL);
+ if (e) {
+ if (!is_simple(e))
+ nasm_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);
+
+ sym = saa_wstruct(syms);
+
+ sym->strpos = pos;
+ sym->type = is_global ? SYM_GLOBAL : 0;
+ sym->segment = segment;
+ if (segment == NO_SEG)
+ sym->type |= SECT_ABS;
+ else if (segment == stext.index) {
+ sym->type |= SECT_TEXT;
+ if (is_global) {
+ sym->next = stext.gsyms;
+ stext.gsyms = sym;
+ } else if (!stext.asym)
+ stext.asym = sym;
+ } else if (segment == sdata.index) {
+ sym->type |= SECT_DATA;
+ if (is_global) {
+ sym->next = sdata.gsyms;
+ sdata.gsyms = sym;
+ } else if (!sdata.asym)
+ sdata.asym = sym;
+ } else if (segment == sbss.index) {
+ sym->type |= SECT_BSS;
+ if (is_global) {
+ sym->next = sbss.gsyms;
+ sbss.gsyms = sym;
+ } else if (!sbss.asym)
+ sbss.asym = sym;
+ } else
+ sym->type = SYM_GLOBAL;
+ if (is_global == 2)
+ sym->value = offset;
+ else
+ sym->value = (sym->type == SYM_GLOBAL ? 0 : offset);
+
+ if (is_global && sym->type != SYM_GLOBAL) {
+ /*
+ * Global symbol exported _from_ this module. We must check
+ * the special text for type information.
+ */
+
+ if (special) {
+ int n = strcspn(special, " ");
+
+ if (!nasm_strnicmp(special, "function", n))
+ sym->type |= SYM_FUNCTION;
+ else if (!nasm_strnicmp(special, "data", n) ||
+ !nasm_strnicmp(special, "object", n))
+ sym->type |= SYM_DATA;
+ else
+ nasm_nonfatal("unrecognised symbol type `%.*s'",
+ n, special);
+ if (special[n]) {
+ struct tokenval tokval;
+ expr *e;
+ int fwd = false;
+ char *saveme = stdscan_get();
+
+ if (!bsd) {
+ nasm_nonfatal("Linux a.out does not support"
+ " symbol size information");
+ } else {
+ while (special[n] && nasm_isspace(special[n]))
+ n++;
+ /*
+ * We have a size expression; attempt to
+ * evaluate it.
+ */
+ sym->type |= SYM_WITH_SIZE;
+ stdscan_reset();
+ stdscan_set(special + n);
+ tokval.t_type = TOKEN_INVALID;
+ e = evaluate(stdscan, NULL, &tokval, &fwd, 0, NULL);
+ if (fwd) {
+ sym->nextfwd = fwds;
+ fwds = sym;
+ sym->name = nasm_strdup(name);
+ } else if (e) {
+ if (!is_simple(e))
+ nasm_nonfatal("cannot use relocatable"
+ " expression as symbol size");
+ else
+ sym->size = reloc_value(e);
+ }
+ }
+ stdscan_set(saveme);
+ }
+ special_used = true;
+ }
+ }
+
+ /*
+ * define the references from external-symbol segment numbers
+ * to these symbol records.
+ */
+ if (segment != NO_SEG && segment != stext.index &&
+ segment != sdata.index && segment != sbss.index)
+ bsym = raa_write(bsym, segment, nsyms);
+ sym->symnum = nsyms;
+
+ nsyms++;
+ if (sym->type & SYM_WITH_SIZE)
+ nsyms++; /* and another for the size */
+
+ if (special && !special_used)
+ nasm_nonfatal("no special symbol features supported here");
+}
+
+static void aout_add_reloc(struct Section *sect, int32_t segment,
+ int reltype, int bytes)
+{
+ struct Reloc *r;
+
+ r = *sect->tail = nasm_malloc(sizeof(struct Reloc));
+ sect->tail = &r->next;
+ r->next = NULL;
+
+ r->address = sect->len;
+ r->symbol = (segment == NO_SEG ? -SECT_ABS :
+ segment == stext.index ? -SECT_TEXT :
+ segment == sdata.index ? -SECT_DATA :
+ segment == sbss.index ? -SECT_BSS :
+ raa_read(bsym, segment));
+ r->reltype = reltype;
+ if (r->symbol >= 0)
+ r->reltype |= RELTYPE_SYMFLAG;
+ r->bytes = bytes;
+
+ 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.
+ *
+ * RELTYPE_GOT references require the _exact_ symbol address to be
+ * used; RELTYPE_ABSOLUTE 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 aout_add_gsym_reloc(struct Section *sect,
+ int32_t segment, int32_t offset,
+ int type, int bytes, int exact)
+{
+ struct Symbol *sym, *sm, *shead;
+ struct Reloc *r;
+
+ /*
+ * First look up the segment to find whether it's text, data,
+ * bss or an external symbol.
+ */
+ shead = NULL;
+ if (segment == stext.index)
+ shead = stext.gsyms;
+ else if (segment == sdata.index)
+ shead = sdata.gsyms;
+ else if (segment == sbss.index)
+ shead = sbss.gsyms;
+ if (!shead) {
+ if (exact && offset != 0)
+ nasm_nonfatal("unable to find a suitable global symbol"
+ " for this reference");
+ else
+ aout_add_reloc(sect, segment, type, bytes);
+ return offset;
+ }
+
+ if (exact) {
+ /*
+ * Find a symbol pointing _exactly_ at this one.
+ */
+ list_for_each(sym, shead)
+ if (sym->value == offset)
+ break;
+ } else {
+ /*
+ * Find the nearest symbol below this one.
+ */
+ sym = NULL;
+ list_for_each(sm, shead)
+ if (sm->value <= offset && (!sym || sm->value > sym->value))
+ sym = sm;
+ }
+ if (!sym && exact) {
+ nasm_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 = sym->symnum;
+ r->reltype = type | RELTYPE_SYMFLAG;
+ r->bytes = bytes;
+
+ sect->nrelocs++;
+
+ return offset - sym->value;
+}
+
+/*
+ * This routine deals with ..gotoff relocations. These _must_ refer
+ * to a symbol, due to a perversity of *BSD's PIC implementation,
+ * and it must be a non-global one as well; so we store `asym', the
+ * first nonglobal symbol defined in each section, and always work
+ * from that. Relocation type is always RELTYPE_GOTOFF.
+ *
+ * Return value is the adjusted value of `addr', having become an
+ * offset from the `asym' symbol rather than the section.
+ */
+static int32_t aout_add_gotoff_reloc(struct Section *sect, int32_t segment,
+ int32_t offset, int bytes)
+{
+ struct Reloc *r;
+ struct Symbol *asym;
+
+ /*
+ * First look up the segment to find whether it's text, data,
+ * bss or an external symbol.
+ */
+ asym = NULL;
+ if (segment == stext.index)
+ asym = stext.asym;
+ else if (segment == sdata.index)
+ asym = sdata.asym;
+ else if (segment == sbss.index)
+ asym = sbss.asym;
+ if (!asym)
+ nasm_nonfatal("`..gotoff' relocations require a non-global"
+ " symbol in the section");
+
+ r = *sect->tail = nasm_malloc(sizeof(struct Reloc));
+ sect->tail = &r->next;
+ r->next = NULL;
+
+ r->address = sect->len;
+ r->symbol = asym->symnum;
+ r->reltype = RELTYPE_GOTOFF;
+ r->bytes = bytes;
+
+ sect->nrelocs++;
+
+ return offset - asym->value;
+}
+
+static void aout_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;
+
+ if (segto == stext.index)
+ s = &stext;
+ else if (segto == sdata.index)
+ s = &sdata;
+ else if (segto == sbss.index)
+ s = NULL;
+ else {
+ nasm_warn(WARN_OTHER, "attempt to assemble code in"
+ " segment %d: defaulting to `.text'", segto);
+ s = &stext;
+ }
+
+ if (!s && type != OUT_RESERVE) {
+ nasm_warn(WARN_OTHER, "attempt to initialize memory in the"
+ " BSS section: ignored");
+ sbss.len += realsize(type, size);
+ return;
+ }
+
+ memset(mydata, 0, sizeof(mydata));
+
+ if (type == OUT_RESERVE) {
+ if (s) {
+ nasm_warn(WARN_ZEROING, "uninitialized space declared in"
+ " %s section: zeroing",
+ (segto == stext.index ? "code" : "data"));
+ aout_sect_write(s, NULL, size);
+ } else
+ sbss.len += size;
+ } else if (type == OUT_RAWDATA) {
+ aout_sect_write(s, data, size);
+ } else if (type == OUT_ADDRESS) {
+ int asize = abs((int)size);
+ addr = *(int64_t *)data;
+ if (segment != NO_SEG) {
+ if (segment % 2) {
+ nasm_nonfatal("a.out format does not support"
+ " segment base references");
+ } else {
+ if (wrt == NO_SEG) {
+ aout_add_reloc(s, segment, RELTYPE_ABSOLUTE, asize);
+ } else if (!bsd) {
+ nasm_nonfatal("Linux a.out format does not support"
+ " any use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ } else if (wrt == aout_gotpc_sect + 1) {
+ is_pic = 0x40;
+ aout_add_reloc(s, segment, RELTYPE_GOTPC, asize);
+ } else if (wrt == aout_gotoff_sect + 1) {
+ is_pic = 0x40;
+ addr = aout_add_gotoff_reloc(s, segment, addr, asize);
+ } else if (wrt == aout_got_sect + 1) {
+ is_pic = 0x40;
+ addr = aout_add_gsym_reloc(s, segment, addr, RELTYPE_GOT,
+ asize, true);
+ } else if (wrt == aout_sym_sect + 1) {
+ addr = aout_add_gsym_reloc(s, segment, addr,
+ RELTYPE_ABSOLUTE, asize,
+ false);
+ } else if (wrt == aout_plt_sect + 1) {
+ is_pic = 0x40;
+ nasm_nonfatal("a.out format cannot produce non-PC-"
+ "relative PLT references");
+ } else {
+ nasm_nonfatal("a.out format does not support this"
+ " use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ }
+ }
+ }
+ p = mydata;
+ if (asize == 2)
+ WRITESHORT(p, addr);
+ else
+ WRITELONG(p, addr);
+ aout_sect_write(s, mydata, asize);
+ } else if (type == OUT_REL2ADR) {
+ if (segment != NO_SEG && segment % 2) {
+ nasm_nonfatal("a.out format does not support"
+ " segment base references");
+ } else {
+ if (wrt == NO_SEG) {
+ aout_add_reloc(s, segment, RELTYPE_RELATIVE, 2);
+ } else if (!bsd) {
+ nasm_nonfatal("Linux a.out format does not support"
+ " any use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ } else if (wrt == aout_plt_sect + 1) {
+ is_pic = 0x40;
+ aout_add_reloc(s, segment, RELTYPE_PLT, 2);
+ } else if (wrt == aout_gotpc_sect + 1 ||
+ wrt == aout_gotoff_sect + 1 ||
+ wrt == aout_got_sect + 1) {
+ nasm_nonfatal("a.out format cannot produce PC-"
+ "relative GOT references");
+ } else {
+ nasm_nonfatal("a.out format does not support this"
+ " use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ }
+ }
+ p = mydata;
+ WRITESHORT(p, *(int64_t *)data - (size + s->len));
+ aout_sect_write(s, mydata, 2L);
+ } else if (type == OUT_REL4ADR) {
+ if (segment != NO_SEG && segment % 2) {
+ nasm_nonfatal("a.out format does not support"
+ " segment base references");
+ } else {
+ if (wrt == NO_SEG) {
+ aout_add_reloc(s, segment, RELTYPE_RELATIVE, 4);
+ } else if (!bsd) {
+ nasm_nonfatal("Linux a.out format does not support"
+ " any use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ } else if (wrt == aout_plt_sect + 1) {
+ is_pic = 0x40;
+ aout_add_reloc(s, segment, RELTYPE_PLT, 4);
+ } else if (wrt == aout_gotpc_sect + 1 ||
+ wrt == aout_gotoff_sect + 1 ||
+ wrt == aout_got_sect + 1) {
+ nasm_nonfatal("a.out format cannot produce PC-"
+ "relative GOT references");
+ } else {
+ nasm_nonfatal("a.out 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 + s->len));
+ aout_sect_write(s, mydata, 4L);
+ }
+}
+
+static void aout_pad_sections(void)
+{
+ static uint8_t pad[] = { 0x90, 0x90, 0x90, 0x90 };
+ /*
+ * Pad each of the text and data sections with NOPs until their
+ * length is a multiple of four. (NOP == 0x90.) Also increase
+ * the length of the BSS section similarly.
+ */
+ aout_sect_write(&stext, pad, (-(int32_t)stext.len) & 3);
+ aout_sect_write(&sdata, pad, (-(int32_t)sdata.len) & 3);
+ sbss.len = ALIGN(sbss.len, 4);
+}
+
+/*
+ * a.out files have the curious property that all references to
+ * things in the data or bss sections are done by addresses which
+ * are actually relative to the start of the _text_ section, in the
+ * _file_. (No relation to what happens after linking. No idea why
+ * this should be so. It's very strange.) So we have to go through
+ * the relocation table, _after_ the final size of each section is
+ * known, and fix up the relocations pointed to.
+ */
+static void aout_fixup_relocs(struct Section *sect)
+{
+ struct Reloc *r;
+
+ saa_rewind(sect->data);
+ list_for_each(r, sect->head) {
+ uint8_t *p, *q, blk[4];
+ int32_t l;
+
+ saa_fread(sect->data, r->address, blk, (int32_t)r->bytes);
+ p = q = blk;
+ l = *p++;
+ if (r->bytes > 1) {
+ l += ((int32_t)*p++) << 8;
+ if (r->bytes == 4) {
+ l += ((int32_t)*p++) << 16;
+ l += ((int32_t)*p++) << 24;
+ }
+ }
+ if (r->symbol == -SECT_DATA)
+ l += stext.len;
+ else if (r->symbol == -SECT_BSS)
+ l += stext.len + sdata.len;
+ if (r->bytes == 4)
+ WRITELONG(q, l);
+ else if (r->bytes == 2)
+ WRITESHORT(q, l);
+ else
+ *q++ = l & 0xFF;
+ saa_fwrite(sect->data, r->address, blk, (int32_t)r->bytes);
+ }
+}
+
+static void aout_write(void)
+{
+ /*
+ * Emit the a.out header.
+ */
+ /* OMAGIC, M_386 or MID_I386, no flags */
+ fwriteint32_t(bsd ? 0x07018600 | is_pic : 0x640107L, ofile);
+ fwriteint32_t(stext.len, ofile);
+ fwriteint32_t(sdata.len, ofile);
+ fwriteint32_t(sbss.len, ofile);
+ fwriteint32_t(nsyms * 12, ofile); /* length of symbol table */
+ fwriteint32_t(0L, ofile); /* object files have no entry point */
+ fwriteint32_t(stext.nrelocs * 8, ofile); /* size of text relocs */
+ fwriteint32_t(sdata.nrelocs * 8, ofile); /* size of data relocs */
+
+ /*
+ * Write out the code section and the data section.
+ */
+ saa_fpwrite(stext.data, ofile);
+ saa_fpwrite(sdata.data, ofile);
+
+ /*
+ * Write out the relocations.
+ */
+ aout_write_relocs(stext.head);
+ aout_write_relocs(sdata.head);
+
+ /*
+ * Write the symbol table.
+ */
+ aout_write_syms();
+
+ /*
+ * And the string table.
+ */
+ fwriteint32_t(strslen + 4, ofile); /* length includes length count */
+ saa_fpwrite(strs, ofile);
+}
+
+static void aout_write_relocs(struct Reloc *r)
+{
+ list_for_each(r, r) {
+ uint32_t word2;
+
+ fwriteint32_t(r->address, ofile);
+
+ if (r->symbol >= 0)
+ word2 = r->symbol;
+ else
+ word2 = -r->symbol;
+ word2 |= r->reltype << 24;
+ word2 |= (r->bytes == 1 ? 0 :
+ r->bytes == 2 ? 0x2000000L : 0x4000000L);
+ fwriteint32_t(word2, ofile);
+ }
+}
+
+static void aout_write_syms(void)
+{
+ uint32_t i;
+
+ saa_rewind(syms);
+ for (i = 0; i < nsyms; i++) {
+ struct Symbol *sym = saa_rstruct(syms);
+ fwriteint32_t(sym->strpos, ofile);
+ fwriteint32_t((int32_t)sym->type & ~SYM_WITH_SIZE, ofile);
+ /*
+ * Fix up the symbol value now we know the final section
+ * sizes.
+ */
+ if ((sym->type & SECT_MASK) == SECT_DATA)
+ sym->value += stext.len;
+ if ((sym->type & SECT_MASK) == SECT_BSS)
+ sym->value += stext.len + sdata.len;
+ fwriteint32_t(sym->value, ofile);
+ /*
+ * Output a size record if necessary.
+ */
+ if (sym->type & SYM_WITH_SIZE) {
+ fwriteint32_t(sym->strpos, ofile);
+ fwriteint32_t(0x0DL, ofile); /* special value: means size */
+ fwriteint32_t(sym->size, ofile);
+ i++; /* use up another of `nsyms' */
+ }
+ }
+}
+
+static void aout_sect_write(struct Section *sect,
+ const uint8_t *data, uint32_t len)
+{
+ saa_wbytes(sect->data, data, len);
+ sect->len += len;
+}
+
+extern macros_t aout_stdmac[];
+
+#endif /* OF_AOUT || OF_AOUTB */
+
+#ifdef OF_AOUT
+
+const struct ofmt of_aout = {
+ "Linux a.out",
+ "aout",
+ ".o",
+ 0,
+ 32,
+ null_debug_arr,
+ &null_debug_form,
+ aout_stdmac,
+ aout_init,
+ null_reset,
+ nasm_do_legacy_output,
+ aout_out,
+ aout_deflabel,
+ aout_section_names,
+ NULL,
+ null_sectalign,
+ null_segbase,
+ null_directive,
+ aout_cleanup,
+ NULL /* pragma list */
+};
+
+#endif
+
+#ifdef OF_AOUTB
+
+const struct ofmt of_aoutb = {
+ "NetBSD/FreeBSD a.out",
+ "aoutb",
+ ".o",
+ 0,
+ 32,
+ null_debug_arr,
+ &null_debug_form,
+ aout_stdmac,
+ aoutb_init,
+ null_reset,
+ nasm_do_legacy_output,
+ aout_out,
+ aout_deflabel,
+ aout_section_names,
+ NULL,
+ null_sectalign,
+ null_segbase,
+ null_directive,
+ aout_cleanup,
+ NULL /* pragma list */
+};
+
+#endif