Remove the --allow-64-bits option and make it a warning
Remove the --allow-64-bits relocation, and instead make it a
suppressible warning in the case of a zero-extended relocation, and an
error in the case of a sign-extended relocation.
Relocations which can be losslessly represented in the output format
do not issue any diagnostic at all, as there is no problem in that
case.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/assemble.c b/assemble.c
index 4976c46..8382b89 100644
--- a/assemble.c
+++ b/assemble.c
@@ -1,6 +1,6 @@
/* ----------------------------------------------------------------------- *
*
- * Copyright 1996-2014 The NASM Authors - All Rights Reserved
+ * Copyright 1996-2016 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
@@ -308,7 +308,8 @@
/*
* This routine wrappers the real output format's output routine,
* in order to pass a copy of the data off to the listing file
- * generator at the same time.
+ * generator at the same time, flatten unnecessary relocations,
+ * and verify backend compatibility.
*/
static void out(int64_t offset, int32_t segto, const void *data,
enum out_type type, uint64_t size,
@@ -317,6 +318,9 @@
static int32_t lineno = 0; /* static!!! */
static char *lnfname = NULL;
uint8_t p[8];
+ const int asize = abs((int)size); /* True address size */
+ const int abits = asize << 3; /* Address size in bits */
+ const int amax = maxbits >> 3; /* Maximum address size in bytes */
if (type == OUT_ADDRESS && segment == NO_SEG && wrt == NO_SEG) {
/*
@@ -325,13 +329,12 @@
*/
uint8_t *q = p;
- size = abs((int)size);
- if (size > 8) {
+ if (asize > 8) {
errfunc(ERR_PANIC, "OUT_ADDRESS with size > 8");
return;
}
- WRITEADDR(q, *(int64_t *)data, size);
+ WRITEADDR(q, *(int64_t *)data, asize);
data = p;
type = OUT_RAWDATA;
}
@@ -350,6 +353,22 @@
if (src_get(&lineno, &lnfname))
outfmt->current_dfmt->linenum(lnfname, lineno, segto);
+ if (type == OUT_ADDRESS && abits > maxbits) {
+ if (asize < 0) {
+ errfunc(ERR_NONFATAL,
+ "%d-bit signed relocation unsupported by output format %s\n",
+ abits, outfmt->shortname);
+ } else {
+ errfunc(ERR_WARNING | ERR_WARN_ZEXTRELOC,
+ "%d-bit unsigned relocation zeroq-padded from %d bits\n",
+ abits, maxbits);
+ outfmt->output(segto, data, type, amax, segment, wrt);
+ size -= amax;
+ }
+ data = zero_buffer;
+ type = OUT_RAWDATA;
+ }
+
outfmt->output(segto, data, type, size, segment, wrt);
}
diff --git a/doc/nasmdoc.src b/doc/nasmdoc.src
index ec0cfcc..4b5078a 100644
--- a/doc/nasmdoc.src
+++ b/doc/nasmdoc.src
@@ -1010,16 +1010,6 @@
some, but not all, system calling conventions.
-\S{opt-allow64bit} The \i\c{--allow-64-bit} Option.
-
-The \c{--allow-64-bit} option allows using 64-bit instructions in a
-32-bit or 16-bit output format. This is useful in a few situations,
-such as when writing code switching from 32-bit to 64-bit mode and
-linking into a 32-bit module. However, it is important to be aware of
-the restriction the output format poses on you in terms of
-relocations. Use with caution!
-
-
\S{nasmenv} The \i\c{NASMENV} \i{Environment} Variable
If you define an environment variable called \c{NASMENV}, the program
diff --git a/nasm.c b/nasm.c
index 17ee553..e48f0a9 100644
--- a/nasm.c
+++ b/nasm.c
@@ -88,7 +88,6 @@
bool tasm_compatible_mode = false;
int pass0, passn;
int maxbits = 0;
-static bool allow_64_bit = false;
int globalrel = 0;
int globalbnd = 0;
@@ -169,6 +168,7 @@
{"lock", "lock prefix on unlockable instructions", true},
{"hle", "invalid hle prefixes", true},
{"bnd", "invalid bnd prefixes", true},
+ {"zero-reloc", "relocation zero-extended to match output format", true},
};
static bool want_usage;
@@ -618,12 +618,10 @@
enum text_options {
OPT_PREFIX,
OPT_POSTFIX,
- OPT_ALLOW_64_BIT
};
struct textargs textopts[] = {
{"prefix", OPT_PREFIX},
{"postfix", OPT_POSTFIX},
- {"allow-64-bit", OPT_ALLOW_64_BIT},
{NULL, 0}
};
@@ -981,9 +979,7 @@
}
break;
}
- case OPT_ALLOW_64_BIT:
- allow_64_bit = true;
- break;
+
default:
{
nasm_error(ERR_NONFATAL | ERR_NOFILE | ERR_USAGE,
@@ -2101,12 +2097,6 @@
"cannot specify 64-bit segment on processor below an x86-64");
i = 16;
}
- if (i != maxbits && !allow_64_bit) {
- nasm_error(ERR_NONFATAL,
- "%s output format does not support 64-bit code",
- ofmt->shortname);
- i = 16;
- }
} else {
nasm_error(pass0 < 2 ? ERR_NONFATAL : ERR_FATAL,
"`%s' is not a valid segment size; must be 16, 32 or 64",
diff --git a/nasm.h b/nasm.h
index 8bc2571..bd1f290 100644
--- a/nasm.h
+++ b/nasm.h
@@ -1,6 +1,6 @@
/* ----------------------------------------------------------------------- *
*
- * Copyright 1996-2014 The NASM Authors - All Rights Reserved
+ * Copyright 1996-2016 The NASM Authors - All Rights Reserved
* See the file AUTHORS included with the NASM distribution for
* the specific copyright holders.
*
diff --git a/nasmlib.h b/nasmlib.h
index 24db573..47e9a0a 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -125,7 +125,8 @@
#define ERR_WARN_LOCK WARN(12) /* bad LOCK prefixes */
#define ERR_WARN_HLE WARN(13) /* bad HLE prefixes */
#define ERR_WARN_BND WARN(14) /* bad BND prefixes */
-#define ERR_WARN_MAX 14 /* the highest numbered one */
+#define ERR_WARN_ZEXTRELOC WARN(15) /* relocation zero-extended */
+#define ERR_WARN_MAX 15 /* the highest numbered one */
/*
* Wrappers around malloc, realloc and free. nasm_malloc will