The "object" symbol keyword would incorrectly generate STT_NOTYPE
instead of STT_OBJECT. Add test for weak object references; they are
different from plain weak references in that they are guaranteed to
resolve to zero if the symbol is not found.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Currently, NASM always issues as an unknown symbol any symbol declared
EXTERN. This is highly undesirable when using common header files,
as it might cause the linker to pull in a bunch of unnecessary
modules, depending on how smart the linker is.
Add a new REQUIRED directive which behaves like the old EXTERN, for
the use cases which might still need this behavior.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
A global or extern definition can now contain the keyword "weak" (or
"strong", although that is the default) to create a weak symbol or a
weak external reference, respectively.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Fix the (severely broken handling of) varadic macros.
Add a conditional comma operator "%,". This expands to a comma unless
followed by a null expansion of some sort, which allows suppressing
the comma before an empty argument (usually varadic, but not
necessarily.)
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
If the address we are using is >= the size of the instruction, then
don't complain on overflow as we can wrap around the top and bottom of
the address space just fine.
Alternatively we could downgrade it to OUT_WRAP in that case.
Reported-by: C. Masloch <pushbx@38.de>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Add a %pragma to set (or clear) listing options. It only takes effect
on the next assembly pass, however!
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Distinguish instructions which have once been valid (OBSOLETE) from
those that never saw the light of day (NEVER). Futhermore, flag
instructions which devolve to an architectural noop from those with
undefined behavior and possibly recycled opcodes.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Just becase one is compiling for an old CPU doesn't mean one wants to
use obsolete instructions that would not be forward compatible. Rename
the "obsolete" warning to "obsolete-removed" and create a new
"obsolete-valid" warning to go with it (-w[+-]obsolete controls both
options, as usual.)
Suggested-by: C. Masloch <pushbx@38.de>
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Add an -L option for additional listing information. Currently
supported is -Le, which emits each line after processing through the
preprocessor, and -Lm, which displays each single-line macro defined
or undefined.
NASM doesn't preserve the names of unused arguments, nor does it have
any technical reason to do so. Instead of adding complexity to save
them, make unnamed parameters official by specifying an empty string
in the argument list.
This has the additional advantage that () is now simply considered a
single empty argument, which means that NASM should now properly
handle things like:
%define myreg() eax
mov edx,myreg()
... similar to how the C preprocessor allows an empty macro argument
list which is distinct from a macro with no arguments whatsoever.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
This allows the K instructions to be specified without a size suffix
as long as the operands are sized; this matches the way most other x86
instructions work. As this is not the syntax specified in the SDM,
don't use it for disassembly.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
All directives which create single-line macros now have %i... variants
to define case-insensitive versions. Case insensitive rather sucks,
but at least this way it is consistent.
Single-line macro parameters can now be evaluated as a number, as done
by %assign. To do so, declare a parameter starting with =, for
example:
%define foo(x,=y) mov [x],macro_array_y
... would evaluate y as a number but leave x as a string.
NOTE: it would arguably be better to have this as a per-instance
basis, but it is easily handled by having a secondary macro called
with the same argument twice.
Finally, add a more consistent method for defining "magic" macros,
which need to be evaluated at runtime. For now, it is only used by the
special macros __FILE__, __LINE__, __BITS__, __PTR__, and __PASS__.
__PTR__ is a new macro which evaluates to word, dword or qword
matching the value of __BITS__.
The magic macro framework, however, provides a natural hook for a
future plug-in infrastructure to hook into a scripting language.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Dead code elimination in ELF uses separate ELF sections for every
functions or data items that may be garbage collected. This can end up
being more than 32,633 sections which, when the ELF internal and
relocation sections are added in, can exceed the legacy ELF maximum of
65,279 sections.
Newer versions of the ELF specification has added support for much
larger number of sections by putting a place holder value (usually
SHN_XINDEX == 0xffff, but 0 in some cases) into fields where the
section index is a 16-bit value, and storing the full value in a
diffent place: the program header uses entries in section header 0,
the symbol table uses an auxiliary segment with the additional
indicies; the section header did not need it as the sh_link field is
already 32 (or 64) bits long.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Use a hash table to look up sections by name, and an RAA to look up
sections by index; thus remove O(n) searches. This becomes important
since ELF uses sections for dead code elimination.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Test case from bug 3392538 for double free in the listing module.
This is the test case only, not a fix.
Reported-by: <russyz@comcast.net>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
AMD documents this instruction with an rax operand. The error behavior
implies this is an address-size-sensitive instruction. Add support for
specifying the explicit operand, but consistent with normal ndisasm
behavior, don't disassemble the implicit operand.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Support the +n syntax for multiple contiguous registers, and emit it
in the output from ndisasm as well.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
absolute.asm is useful even for other backends, so explicitly test to
see if ORG is possible for this format.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Add a simple test case for context-local (%$) labels not disturbing
the local variable namespace, and extern labels getting promoted to
global.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
There are cases where we may want to implement generic pragmas, while
still make them selective based on output and/or debug formats.
Initially, use this for the prefix/suffix options.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Chang Seok Bae <chang.seok.bae@intel.com>
It is quite likely we may want to build the same input with multiple
output formats; make it so we don't lose the list file.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
In order to support Mach-O better, add support for subsections, as
used by Mach-O "subsections_via_symbols". We also want to add
infrastructure to support this by downcalling to the backend to
indicate if a new subsection is needed.
Currently this supports a maximum of 2^14 subsections per section for
Mach-O; this can be addressed by adding a level of indirection (or
cleaning up the handling of sections so we have an actual data
structure.)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
"output" and "debug" are supposed to redirect to the current output
and debug formats. Fix it so it actually does.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Make it possible to generate variants of RET(F) with explicit operand
size specified without having to use o16/o32/o64.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Automatically assign values to the instruction flags; we ended up with
a case where pushing flags into the next dword caused comparison
failures due to other places in the code explicitly comparing
field[3].
This creates necessary defines for this not to happen; it also cleans
up a fair bit of the iflag code.
This resolves BR 3392454.
Reported-by: Thomasz Kantecki <tomasz.kantecki@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The calculation of vmin in overflow_general() was bogus, causing
silliness like ~80h being warned about in a byte context.
Reported-by: C. Masloch <pushbx@38.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We could generate the MRI version (SSE 4.1) instead of the RMI
(SSE 2) version of these instructions if a 64-bit register was given
as the destination.
Reported-by: Vasiliy Olekhov <olekhov@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We need to always define the end symbol, otherwise we might find
ourselves in a situation where the alignment code grows (common!) and
then the symbol is defined late.
Reported-by: ig <glucksmann@avast.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Issue a diagnostic and don't panic for invalid TIMES values.
Reported-by: C. Masloch <pushbx@38.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Support 16-character section names, and support the debug section
flag.
Reported-by: Andrey Timofeyev <timofeyev@bk.ru>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
