The aim of this patch is to fix the following piece of code in the
platform-independent AsmParser:
void AsmParser::CheckForValidSection() {
if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
TokError("expected section directive before assembly directive");
Out.SwitchSection(Ctx.getMachOSection(
"__TEXT", "__text",
MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
0, SectionKind::getText()));
}
}
This was added for the "-n" option of llvm-mc.
The proposed fix adds another virtual method to MCStreamer, called
InitToTextSection. Conceptually, it's similar to the existing
InitSections which initializes all common sections and switches to
text. The new method is implemented by each platform streamer in a way
that it sees fit. So AsmParser can now do this:
void AsmParser::CheckForValidSection() {
if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
TokError("expected section directive before assembly directive");
Out.InitToTextSection();
}
}
Which is much more reasonable.
llvm-svn: 172450
Mips16 is really a processor decoding mode (ala thumb 1) and in the same
program, mips16 and mips32 functions can exist and can call each other.
If a jal type instruction encounters an address with the lower bit set, then
the processor switches to mips16 mode (if it is not already in it). If the
lower bit is not set, then it switches to mips32 mode.
The linker knows which functions are mips16 and which are mips32.
When relocation is performed on code labels, this lower order bit is
set if the code label is a mips16 code label.
In general this works just fine, however when creating exception handling
tables and dwarf, there are cases where you don't want this lower order
bit added in.
This has been traditionally distinguished in gas assembly source by using a
different syntax for the label.
lab1: ; this will cause the lower order bit to be added
lab2=. ; this will not cause the lower order bit to be added
In some cases, it does not matter because in dwarf and debug tables
the difference of two labels is used and in that case the lower order
bits subtract each other out.
To fix this, I have added to mcstreamer the notion of a debuglabel.
The default is for label and debug label to be the same. So calling
EmitLabel and EmitDebugLabel produce the same result.
For various reasons, there is only one set of labels that needs to be
modified for the mips exceptions to work. These are the "$eh_func_beginXXX"
labels.
Mips overrides the debug label suffix from ":" to "=." .
This initial patch fixes exceptions. More changes most likely
will be needed to DwarfCFException to make all of this work
for actual debugging. These changes will be to emit debug labels in some
places where a simple label is emitted now.
Some historical discussion on this from gcc can be found at:
http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.htmlhttp://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html
llvm-svn: 170279
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
The target backend can support data-in-code load commands even when
the assembler doesn't, or vice-versa. Allow targets to opt-in for
direct-to-object.
PR13973.
llvm-svn: 164974
- Darwin lied about not supporting .lcomm and turned it into zerofill in the
asm parser. Push the zerofill-conversion down into macho-specific code.
- This makes the tri-state LCOMMType enum superfluous, there are no targets
without .lcomm.
- Do proper error reporting when trying to use .lcomm with alignment on a target
that doesn't support it.
- .comm and .lcomm alignment was parsed in bytes on COFF, should be power of 2.
- Fixes PR13755 (.lcomm crashes on ELF).
llvm-svn: 163395
Use a dedicated MachO load command to annotate data-in-code regions.
This is the same format the linker produces for final executable images,
allowing consistency of representation and use of introspection tools
for both object and executable files.
Data-in-code regions are annotated via ".data_region"/".end_data_region"
directive pairs, with an optional region type.
data_region_directive := ".data_region" { region_type }
region_type := "jt8" | "jt16" | "jt32" | "jta32"
end_data_region_directive := ".end_data_region"
The previous handling of ARM-style "$d.*" labels was broken and has
been removed. Specifically, it didn't handle ARM vs. Thumb mode when
marking the end of the section.
rdar://11459456
llvm-svn: 157062
file error checking. Use that to error on an unfinished cfi_startproc.
The error is not nice, but is already better than a segmentation fault.
llvm-svn: 147717
- On COFF the .lcomm directive has an alignment argument.
- On ELF we fall back to .local + .comm
Based on a patch by NAKAMURA Takumi.
Fixes PR9337, PR9483 and PR10128.
llvm-svn: 138976
assert-path code, as previously we would have fallen off the end of the
function, but please review and let me know if this should go somewhere
else.
This fixes a Clang warning:
lib/MC/MCMachOStreamer.cpp:201:11: error: enumeration value 'MCSA_IndirectSymbol' not handled in switch [-Werror,-Wswitch-enum]
switch (Attribute) {
^
1 error generated.
llvm-svn: 135976
The .local, .hidden, .internal, and .protected are not legal for all supported
file formats (in particular, they're invalid for MachO). Move the parsing for
them into the ELF assembly parser since that's the format they're for.
Similarly, .weak is used by COFF and ELF, but not MachO, so move the parsing
to the COFF and ELF asm parsers. Previously, using any of these directives
on Darwin would result in an assertion failure in the parser; now we get
a diagnostic as we should.
rdar://9827089
llvm-svn: 135921
TargetAsmInfo, which in turn pulls in TargetRegisterInfo, etc. :-( There are
other cases of violations, but this is probably the worst.
This patch is but one small step towards fixing this. 500 more steps to go. :-(
llvm-svn: 135131
Currently the output should be almost identical to the one produced by CodeGen
to make the transition easier.
The only two differences I know of are:
* Some files get an extra advance loc of size 0. This will be fixed when
relaxations are enabled.
* The optimization of declaring an EH symbol as an external variable is not
implemented. This is a subset of adding the nounwind attribute, so we if really
this at -O0 we should probably do it at the IL level.
llvm-svn: 130623
actuall addresses in a .o file, so it is better to let the MachO writer compute
it.
This is good for two reasons. First, areas that shouldn't care about
addresses now don't have access to it. Second, the layout of each section
is independent. I should use this in a subsequent commit to speed it up.
Most of the patch is just removing the section address computation. The two
interesting parts are the change on how we handle padding in the end
of sections and how MachO can get the address of a-b when a and b are in
different sections.
Since now the expression evaluation normally doesn't know the section address,
it will think that a-b needs relocation and let the MachO writer know. Once
it has computed the section addresses, it calls back the expression evaluation
with the section addresses to resolve these expressions.
The remaining problem is the handling of padding. Currently it will create
a special alignment fragment at the end. Since that fragment doesn't update
the alignment of the section, it needs the real address to be computed.
Since now the layout will not compute a-b with a and b in different sections,
the only effect that the special alignment fragment has is update the
address size of the section. This can also be done by the MachO writer.
llvm-svn: 121076
MCStreamer instead of just MCObjectStreamer. Address changes cannot
be as efficient as we have to use DW_LNE_set_addres, but at least
most of the logic is shared.
This will be used so that, with CodeGen still using EmitDwarfLocDirective,
llvm-gcc is able to produce debug_line sections without needing an
assembler that supports .loc.
llvm-svn: 119777
where both symbols are "local", that is non-external symbols, and there is
no "base" for the symbols used in the expression, that is the section has
no non-temporary symbols. This case looks like this:
% cat local_reloc_A-B.s
.long 0
LB: .long 1
.long LA - LB - 4
.long 2
LA: .long 3
which llvm-mc will not encode without this patch, generates a "unsupported
local relocations in difference" error, but the Darwin assembler will
encode with relocation entries like this:
% otool -rv a.out l.out
a.out:
Relocation information (__TEXT,__text) 2 entries
address pcrel length extern type scattered symbolnum/value
00000008 False long False SUB False 1 (__TEXT,__text)
00000008 False long False UNSIGND False 1 (__TEXT,__text)
which is very similar to what is encoded when the symbols don't have the
leading 'L' and they are not temporary symbols. Which llvm-mc and the
Darwin assembler will encoded like this:
Relocation information (__TEXT,__text) 2 entries
address pcrel length extern type scattered symbolnum/value
00000008 False long True SUB False B
00000008 False long True UNSIGND False A
This is the missing relocation encoding needed to allow the Mach-O x86
Dwarf file and line table to be emitted. So this patch also removes the
TODO from the if() statement in MCMachOStreamer::Finish() that didn't
call MCDwarfFileTable::Emit() for 64-bit targets.
llvm-svn: 115389
and output the dwarf line number tables. This contains the code to emit and
encode the dwarf line tables from the previously gathered information in the
MCLineSection objects. This contains all the details to encode the line and
address deltas into the dwarf line table.
To do this an MCDwarfLineAddrFragment has been added.
Also this moves the interface code out of Mach-O streamer into
MCDwarf so it should be useable by other object file formats.
There is now one call to be made from an MCObjectStreamer
EmitInstruction() method:
MCLineEntry::Make(this, getCurrentSection());
to create a line entry after each instruction is assembled.
And one call call to be made from an MCObjectStreamer Finish() method:
MCDwarfFileTable::Emit(this, DwarfLineSection);
when getContext().hasDwarfFiles() is true and is passed a object file specific
MCSection where to emit the dwarf file and the line tables.
This appears to now be correct for 32-bit targets, at least x86. But the
relocation entries for 64-bit Darwin needs some further work which is next
up to work on. So for now the 64-bit Mach-O target does not output the
dwarf file and line tables.
llvm-svn: 115157
The ELF implementation now creates text, data and bss to match the gnu as
behavior.
The text streamer still has the old MachO specific behavior since
the testsuite checks that it will error when a directive is given
before a setting the current section for example.
A nice benefit is that -n is not required anymore when producing
ELF files.
llvm-svn: 114027
and output the dwarf line number tables. This takes the current loc info after
an instruction is assembled and saves the needed info into an object that has
vector and for each section. These objects will be used for the final patch to
build and emit the encoded dwarf line number tables. Again for now this is only
in the Mach-O streamer but at some point will move to a more generic place.
llvm-svn: 112668
previously collected info from the .file directives and outputs the encoded
bytes for it. For now this is only in the Mach-O streamer but at some point
will move to a more generic place.
llvm-svn: 110617
- Don't clear weak reference flag, 'as' was only "trying" to do this, it wasn't
actually succeeding.
- Clear the "lazy bound" bit when we mark something external. This corresponds
roughly to the lazy clearing of the bit that 'as' implements in
symbol_table_lookup.
- The exact meaning of these flags appears pretty loose, since 'as' isn't very
consistent. For now we just try to match 'as', we will clean this up one day
hopefully.
llvm-svn: 103964
Eli Bendersky