[Nasm-commits] [nasm:macho64] modified: output/outmacho64.c
nasm-bot for Keith
keith at Voyager.local
Thu Jun 4 19:56:16 PDT 2020
Commit-ID: 190995ac29961b15cca298f18a0fa685822d6520
Gitweb: http://repo.or.cz/w/nasm.git?a=commitdiff;h=190995ac29961b15cca298f18a0fa685822d6520
Author: Keith <keith at Voyager.local>
AuthorDate: Thu, 9 Oct 2008 21:22:26 -0500
Committer: Keith <keith at Voyager.local>
CommitDate: Thu, 9 Oct 2008 21:22:26 -0500
modified: output/outmacho64.c
---
output/outmacho64.c | 106 ++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 77 insertions(+), 29 deletions(-)
diff --git a/output/outmacho64.c b/output/outmacho64.c
index 0e4d991c..3624a39a 100644
--- a/output/outmacho64.c
+++ b/output/outmacho64.c
@@ -25,7 +25,7 @@
#include "outform.h"
#include "compiler.h"
-#if defined(OF_MACHO64)
+#ifdef OF_MACHO64
/* Mach-O in-file header structure sizes */
#define MACHO_HEADER64_SIZE (32)
@@ -66,6 +66,7 @@ struct section {
uint64_t size; /* in-memory and -file size */
uint32_t nreloc; /* relocation entry count */
uint32_t flags; /* type and attributes (masked) */
+ uint32_t extreloc; /* external relocations */
};
#define SECTION_TYPE 0x000000ff /* section type mask */
@@ -182,7 +183,7 @@ static FILE *machofp;
static efunc error;
static evalfunc evaluate;
-extern struct ofmt of_macho;
+extern struct ofmt of_macho64;
/* Global file information. This should be cleaned up into either
a structure or as function arguments. */
@@ -302,6 +303,13 @@ static uint8_t get_section_fileindex_by_index(const int32_t index)
return NO_SECT;
}
+/*
+ * Special section numbers which are used to define Mach-O special
+ * symbols, which can be used with WRT to provide PIC relocation
+ * types.
+ */
+static int32_t macho_gotpcrel_sect;
+
static void macho_init(FILE * fp, efunc errfunc, ldfunc ldef,
evalfunc eval)
{
@@ -330,6 +338,11 @@ static void macho_init(FILE * fp, efunc errfunc, ldfunc ldef,
/* string table starts with a zero byte - don't ask why */
saa_wbytes(strs, &zero, sizeof(char));
strslen = 1;
+
+ /* add special symbol for ..gotpcrel */
+ macho_gotpcrel_sect = seg_alloc();
+ macho_gotpcrel_sect ++;
+ ldef("..gotpcrel", macho_gotpcrel_sect, 0L, NULL, false, false, &of_macho64, error);
}
static int macho_setinfo(enum geninfo type, char **val)
@@ -392,6 +405,8 @@ static void add_reloc(struct section *sect, int32_t section,
/* relative relocation */
if (pcrel == 1) {
+// r->type = 2; // X86_64_RELOC_BRANCH
+
/* intra-section */
if (section == NO_SEG) {
r->type = 1; // X86_64_RELOC_SIGNED
@@ -402,22 +417,28 @@ static void add_reloc(struct section *sect, int32_t section,
/* external */
if (fi == NO_SECT) {
- r->snum = raa_read(extsyms, section);
+ sect->extreloc = 1;
+
+ r->pcrel = 0; // presumed X86_64_RELOC_UNSIGNED ???
+// r->snum = raa_read(extsyms, section);
/* local */
} else {
+
r->type = 2; // X86_64_RELOC_BRANCH
r->snum = fi;
-
- /* standard relocation */
- r->type = 1; // X86_64_RELOC_SIGNED
-
}
}
/* subtractor */
- } else if(pcrel == 2) {
+ } else if (pcrel == 2) {
+ r->pcrel = 0;
r->type = 5; // X86_64_RELOC_SUBTRACTOR
+// r->snum = macho_gotpcrel_sect;
+
+ /* gotpcrel */
+ } else if (pcrel == 3) {
+ r->type = 4; // X86_64_RELOC_GOT
}
++sect->nreloc;
}
@@ -427,14 +448,8 @@ static void macho_output(int32_t secto, const void *data,
int32_t section, int32_t wrt)
{
struct section *s, *sbss;
- int32_t addr;
- uint8_t mydata[8], *p;
-
- if (wrt != NO_SEG) {
- wrt = NO_SEG;
- error(ERR_NONFATAL, "WRT not supported by Mach-O output format");
- /* continue to do _something_ */
- }
+ int64_t addr;
+ uint8_t mydata[16], *p;
if (secto == NO_SEG) {
if (type != OUT_RESERVE)
@@ -509,13 +524,15 @@ static void macho_output(int32_t secto, const void *data,
} else {
if (wrt == NO_SEG) {
if (size < 8) {
-// add_reloc(s, section, 2, size);
-// sect_write(s, data, size);
+ add_reloc(s, section, 2, size);
}
add_reloc(s, section, 0, size);
- }else{
+ } else if (wrt == macho_gotpcrel_sect) {
+ addr += s->size;
+ add_reloc(s, section, 3, size);
+ } else {
error(ERR_NONFATAL, "Mach-O format does not support"
- " this... um... thingy right now...");
+ " this use of WRT");
}
}
}
@@ -533,27 +550,44 @@ static void macho_output(int32_t secto, const void *data,
error(ERR_NONFATAL, "Mach-O format does not support"
" section base references");
} else {
- add_reloc(s, section, 1, 2);
+ if (wrt == NO_SEG) {
+ add_reloc(s, section, 2, 2);
+ add_reloc(s, section, 0, 2);
+ } else {
+ error(ERR_NONFATAL, "Unsupported non-32-bit"
+ " Macho-O relocation [2]");
+ }
}
p = mydata;
- WRITESHORT(p, *(int32_t *)data - (size + s->size));
+ WRITESHORT(p, *(int64_t *)data - size);
sect_write(s, mydata, 2L);
break;
case OUT_REL4ADR:
-// if (section == secto)
-// error(ERR_PANIC, "intra-section OUT_REL4ADR");
+ if (section == secto)
+ error(ERR_PANIC, "intra-section OUT_REL4ADR");
if (section != NO_SEG && section % 2) {
error(ERR_NONFATAL, "Mach-O format does not support"
" section base references");
} else {
- add_reloc(s, section, 1, 4);
+ if (wrt == NO_SEG) {
+
+//add_reloc(s, section, 2, 4);
+ add_reloc(s, section, 1, 4);
+ } else if (wrt == macho_gotpcrel_sect) {
+ error(ERR_NONFATAL, "Mach-O format cannot produce PC-"
+ "relative GOT references");
+ } else {
+ error(ERR_NONFATAL, "Mach-O format does not support"
+ " this use of WRT");
+ wrt = NO_SEG; /* we can at least _try_ to continue */
+ }
}
p = mydata;
- WRITELONG(p, *(int32_t *)data - (size + s->size));
+ WRITELONG(p, *(int64_t *)data - size);
sect_write(s, mydata, 4L);
break;
@@ -700,7 +734,18 @@ static void macho_symdef(char *name, int32_t section, int64_t offset,
sym->desc = 0;
sym->value = offset;
sym->initial_snum = -1;
-
+
+ if (name[0] == '.' && name[1] == '.' && name[2] != '@') {
+ /*
+ * This is a NASM special symbol. We never allow it into
+ * the Macho-O symbol table, even if it's a valid one. If it
+ * _isn't_ a valid one, we should barf immediately.
+ */
+ if (strcmp(name, "..gotpcrel"))
+ error(ERR_NONFATAL, "unrecognised special symbol `%s'", name);
+ return;
+ }
+
/* external and common symbols get N_EXT */
if (is_global != 0) {
sym->type |= N_EXT;
@@ -967,7 +1012,11 @@ static uint32_t macho_write_segment (uint64_t offset)
fwriteint32_t(0, machofp);
}
- if(s->nreloc) s->flags |= S_ATTR_LOC_RELOC;
+ if (s->nreloc) {
+ s->flags |= S_ATTR_LOC_RELOC;
+ if (s->extreloc)
+ s->flags |= S_ATTR_EXT_RELOC;
+ }
fwriteint32_t(s->flags, machofp); /* flags */
fwriteint32_t(0, machofp); /* reserved */
fwriteint32_t(0, machofp); /* reserved */
@@ -998,7 +1047,6 @@ static void macho_write_relocs (struct reloc *r)
word2 |= r->ext << 27;
word2 |= r->type << 28;
fwriteint32_t(word2, machofp); /* reloc data */
-
r = r->next;
}
}
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