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-rw-r--r--output/outmacho.c60
1 files changed, 41 insertions, 19 deletions
diff --git a/output/outmacho.c b/output/outmacho.c
index 94465e43..56b53d47 100644
--- a/output/outmacho.c
+++ b/output/outmacho.c
@@ -179,6 +179,9 @@ struct section {
#define S_ATTR_PURE_INSTRUCTIONS 0x80000000 /* section uses pure
machine instructions */
+/* Fake section for absolute symbols, *not* part of the section linked list */
+static struct section absolute_sect;
+
static const struct sectmap {
const char *nasmsect;
const char *segname;
@@ -197,10 +200,10 @@ struct reloc {
struct reloc *next;
/* data that goes into the file */
- int32_t addr; /* op's offset in section */
- uint32_t snum:24, /* contains symbol index if
- ** ext otherwise in-file
- ** section number */
+ int32_t addr; /* op's offset in section */
+ uint32_t snum:24, /* contains symbol index if
+ ** ext otherwise in-file
+ ** section number */
pcrel:1, /* relative relocation */
length:2, /* 0=byte, 1=word, 2=int32_t, 3=int64_t */
ext:1, /* external symbol referenced */
@@ -274,8 +277,6 @@ static struct RAA *extsyms;
static struct SAA *strs;
static uint32_t strslen;
-extern const struct ofmt of_macho64;
-
/* Global file information. This should be cleaned up into either
a structure or as function arguments. */
static uint32_t head_ncmds = 0;
@@ -338,6 +339,9 @@ static void macho_init(void)
sects = NULL;
sectstail = &sects;
+ /* Fake section for absolute symbols */
+ absolute_sect.index = NO_SEG;
+
syms = NULL;
symstail = &syms;
nsyms = 0;
@@ -376,8 +380,9 @@ static struct symbol *macho_find_gsym(struct section *s,
srb = rb_search(s->gsyms, offset);
if (!srb || (exact && srb->key != offset)) {
- nasm_error(ERR_NONFATAL, "unable to find a suitable global symbol"
- " for this reference");
+ nasm_error(ERR_NONFATAL, "unable to find a suitable %s symbol"
+ " for this reference",
+ s == &absolute_sect ? "absolute" : "global");
return NULL;
}
@@ -436,21 +441,33 @@ static int64_t add_reloc(struct section *sect, int32_t section,
}
break;
- case RL_BRANCH:
- r->type = X86_64_RELOC_BRANCH;
- goto rel_or_branch;
-
case RL_REL:
+ case RL_BRANCH:
r->type = fmt.reloc_rel;
-
- rel_or_branch:
r->pcrel = 1;
if (section == NO_SEG) {
- goto bail; /* No relocation needed */
+ /* absolute - seems to produce garbage no matter what */
+ nasm_error(ERR_NONFATAL, "Mach-O does not support relative "
+ "references to absolute addresses");
+ goto bail;
+#if 0
+ /* This "seems" to be how it ought to work... */
+
+ struct symbol *sym = macho_find_gsym(&absolute_sect,
+ offset, false);
+ if (!sym)
+ goto bail;
+
+ sect->extreloc = 1;
+ r->snum = NO_SECT;
+ adjust = -sect->size;
+#endif
} else if (fi == NO_SECT) {
/* external */
sect->extreloc = 1;
r->snum = raa_read(extsyms, section);
+ if (reltype == RL_BRANCH)
+ r->type = X86_64_RELOC_BRANCH;
} else {
/* local */
r->ext = 0;
@@ -647,7 +664,7 @@ static void macho_output(int32_t secto, const void *data,
saa_fread(s->data, 0, opcode+1, 1);
}
- if (opcode[1] == 0xe8 || opcode[1] == 0xe9 ||
+ if ((opcode[0] != 0x0f && (opcode[1] & 0xfe) == 0xe8) ||
(opcode[0] == 0x0f && (opcode[1] & 0xf0) == 0x80)) {
/* Direct call, jmp, or jcc */
reltype = RL_BRANCH;
@@ -821,7 +838,8 @@ static int32_t macho_section(char *name, int pass, int *bits)
s->align = newAlignment;
} else if (!nasm_stricmp("data", currentAttribute)) {
flags = S_REGULAR;
- } else if (!nasm_stricmp("code", currentAttribute)) {
+ } else if (!nasm_stricmp("code", currentAttribute) ||
+ !nasm_stricmp("text", currentAttribute)) {
flags = S_REGULAR | S_ATTR_SOME_INSTRUCTIONS |
S_ATTR_PURE_INSTRUCTIONS;
} else if (!nasm_stricmp("mixed", currentAttribute)) {
@@ -898,6 +916,9 @@ static void macho_symdef(char *name, int32_t section, int64_t offset,
/* symbols in no section get absolute */
sym->type |= N_ABS;
sym->sect = NO_SECT;
+
+ /* all absolute symbols are available to use as references */
+ absolute_sect.gsyms = rb_insert(absolute_sect.gsyms, &sym->symv);
} else {
struct section *s = get_section_by_index(section);
@@ -1103,7 +1124,6 @@ static void macho_calculate_sizes (void)
* perhaps aligning to pointer size would be better.
*/
s->pad = ALIGN(seg_filesize, 4) - seg_filesize;
- // s->pad = ALIGN(seg_filesize, 1U << s->align) - seg_filesize;
s->offset = seg_filesize + s->pad;
seg_filesize += s->size + s->pad;
}
@@ -1128,7 +1148,7 @@ static void macho_calculate_sizes (void)
/* Create a table of sections by file index to avoid linear search */
sectstab = nasm_malloc((seg_nsects + 1) * sizeof(*sectstab));
- sectstab[0] = NULL;
+ sectstab[NO_SECT] = &absolute_sect;
for (s = sects, fi = 1; s != NULL; s = s->next, fi++)
sectstab[fi] = s;
}
@@ -1302,6 +1322,8 @@ static void macho_write_section (void)
/* generate final address by section address and offset */
nasm_assert(r->snum <= seg_nsects);
l += sectstab[r->snum]->addr;
+ if (r->pcrel)
+ l -= s->addr;
}
/* write new offset back */