ARMTargetStreamer implements ConstantPool and AssmeblerConstantPools
to keep track of assembler-generated constant pools that are used for
ldr-pseudo.
When implementing ldr-pseudo for AArch64, these two classes can be reused.
So this patch factors them out from ARM target to the general MC lib.
llvm-svn: 211198
This corrects the emission of IMAGE_REL_ARM_MOV32T relocations. Previously, we
were avoiding the high portion of the relocation too early. If there was a
section-relative relocation with an offset greater than 16-bits (65535), you
would end up truncating the high order bits of the offset. Allow the current
relocation representation to flow through out the MC layer to the object writer.
Use the new ability to restrict recorded relocations to avoid emitting the
relocation into the final object.
llvm-svn: 209337
This commit was already commited as revision rL208689 and discussd in
phabricator revision D3704.
But the test file was crashing on OS X and windows.
I fixed the test file in the same way as in rL208340.
llvm-svn: 208711
This adds FK_SecRel_2 relocation support to ARM. This enables the building of
object files for armv7-windows-msvc which enables CodeView line tables for
debugging as opposed to armv7-windows-itanium which currently uses DWARF.
llvm-svn: 208273
Add handling for FK_SecRel_4 (4-byte section relative relocations). These are
used by the generation of DWARF debug information (the abbrevations use section
relative relocations). This will also be used in generation of CodeView line
tables.
llvm-svn: 207941
The fix itself is fairly simple: move getAccessVariant to MCValue so that we
replace the old weak expression evaluation with the far more general
EvaluateAsRelocatable.
This then requires that EvaluateAsRelocatable stop when it finds a non
trivial reference kind. And that in turn requires the ELF writer to look
harder for weak references.
Last but not least, this found a case where we were being bug by bug
compatible with gas and accepting an invalid input. I reported pr19647
to track it.
llvm-svn: 207920
We currently force symbols to be globals in .thumb_set. The intent
seems to be that given
.thumb_set foo, bar
we emit an undefined symbol to bar if it is never defined. The side
effect is that we mark bar as global, even if it is defined, which gas
does not.
Producing an undefined reference to bar is a general difference from MC and gas.
For example, given
a = b
gas will produce an undefined reference to b, MC will not. I would be surprised
if any code depends on this, but it it does, we should fix the general
difference, not special case .thumb_set.
llvm-svn: 207757
This patch centralizes the handling of the thumb bit around
MCStreamer::isThumbFunc and makes isThumbFunc handle aliases.
This fixes a corner case, but the main advantage is having just one
way to check if a MCSymbol is thumb or not. This should still be
refactored to be ARM only, but at least now it is just one predicate
that has to be refactored instead of 3 (isThumbFunc,
ELF_Other_ThumbFunc, and SF_ThumbFunc).
llvm-svn: 207522
Only the object streamers need to track if a symbol should be marked thumb or
not. This ports the ELF case. The COFF case is not ported since it is currently
not working for some other reason (I will report a bug).
llvm-svn: 207366
Introduce support for WoA PE/COFF object file emission from LLVM. Add the new
target specific PE/COFF Streamer (ARMWinCOFFStreamer) that handles the ARM
specific behaviour of PE/COFF object emission. ARM exception information is not
yet emitted and is a TODO item.
The ARM specific object writer (ARMWinCOFFObjectWriter) handles the ARM specific
relocation handling in conjunction with the WinCOFFObjectWriter in the MC layer.
The MC layer needs to be updated to deal with the relocation adjustments.
Branch relocations are adjusted by 4 bytes (unlikely their ELF counterparts).
Minor tweaks to switch multiple conditional checks into equivalent switch
statements. The ObjectFileInfo is updated to relax the object file setup for
Windows COFF. Move the architecture checks into an assertion. Windows COFF is
currently only supported on x86, x86_64, and ARM (thumb). Rather than
defaulting to ELF, we will refuse to generate an object file. This is better
though as you do not get an (arbitrary) object file which is different from the
request.
llvm-svn: 207345
Currently, the integrated assembler is the only choice for assembling Windows on
ARM binaries. IAS supports the .file <filename> directive which emits the file
symbol into the resulting object binary. Mark the GNU COFF information to
indicate support for this feature.
llvm-svn: 207341
I discovered this const-hole while attempting to coalesnce the Symbol
and SymbolMap data structures. There's some pending issues with that,
but I figured this change was easy to flush early.
llvm-svn: 207124
diagnostic that includes location information.
Currently if one has this assembly:
.quad (0x1234 + (4 * SOME_VALUE))
where SOME_VALUE is undefined ones gets the less than
useful error message with no location information:
% clang -c x.s
clang -cc1as: fatal error: error in backend: expected relocatable expression
With this fix one now gets a more useful error message
with location information:
% clang -c x.s
x.s:5:8: error: expected relocatable expression
.quad (0x1234 + (4 * SOME_VALUE))
^
To do this I plumbed the SMLoc through the MCObjectStreamer
EmitValue() and EmitValueImpl() interfaces so it could be used
when creating the MCFixup.
rdar://12391022
llvm-svn: 206906
expressions for mov instructions instead of silently truncating by default.
For the ARM assembler, we want to avoid misleadingly allowing something
like "mov r0, <symbol>" especially when we turn it into a movw and the
expression <symbol> does not have a :lower16: or :upper16" as part of the
expression. We don't want the behavior of silently truncating, which can be
unexpected and lead to bugs that are difficult to find since this is an easy
mistake to make.
This does change the previous behavior of llvm but actually matches an
older gnu assembler that would not allow this but print less useful errors
of like “invalid constant (0x927c0) after fixup” and “unsupported relocation on
symbol foo”. The error for llvm is "immediate expression for mov requires
:lower16: or :upper16" with correct location information on the operand
as shown in the added test cases.
rdar://12342160
llvm-svn: 206669
Issue subject: Crash using integrated assembler with immediate arithmetic
Fix description:
Expressions like 'cmp r0, #(l1 - l2) >> 3' could not be evaluated on asm parsing stage,
since it is impossible to resolve labels on this stage. In the end of stage we still have
expression (MCExpr).
Then, when we want to encode it, we expect it to be an immediate, but it still an expression.
Patch introduces a Fixup (MCFixup instance), that is processed after main encoding stage.
llvm-svn: 205094
I started trying to fix a small issue, but this code has seen a small fix too
many.
The old code was fairly convoluted. Some of the issues it had:
* It failed to check if a symbol difference was in the some section when
converting a relocation to pcrel.
* It failed to check if the relocation was already pcrel.
* The pcrel value computation was wrong in some cases (relocation-pc.s)
* It was missing quiet a few cases where it should not convert symbol
relocations to section relocations, leaving the backends to patch it up.
* It would not propagate the fact that it had changed a relocation to pcrel,
requiring a quiet nasty work around in ARM.
* It was missing comments.
llvm-svn: 205076
Fix description:
Expressions like 'cmp r0, #(l1 - l2) >> 3' could not be evaluated on asm parsing stage,
since it is impossible to resolve labels on this stage. In the end of stage we still have
expression (MCExpr).
Then, when we want to encode it, we expect it to be an immediate, but it still an expression.
Patch introduces a Fixup (MCFixup instance), that is processed after main encoding stage.
llvm-svn: 204899
Given
bar = foo + 4
.long bar
MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.
Fixing this unfortunately required some other changes:
* Since the variable is now evaluated, it would prevent the ELF writer from
noticing the weakref marker the elf streamer uses. This patch then replaces
that with a VariantKind in MCSymbolRefExpr.
* Using VariantKind then requires us to look past other VariantKind to see
.weakref bar,foo
call bar@PLT
doing this also fixes
zed = foo +2
call zed@PLT
so that is a good thing.
* Looking past VariantKind means that the relocation selection has to use
the fixup instead of the target.
This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.
llvm-svn: 204294
This is a follow-up to r203635. Saleem pointed out that since symbolic register
names are much easier to read, it would be good if we could turn them off only
when we really need to because we're using an external assembler.
Differential Revision: http://llvm-reviews.chandlerc.com/D3056
llvm-svn: 203806
Support to the IAS was added to actually parse and handle the complex SO
expressions. However, the object file lowering was not updated to compensate
for the fact that the shift operand may be an absolute expression.
When trying to assemble to an object file, the lowering would fail while
succeeding when emitting purely assembly. Add an appropriate test.
The test case is inspired by the test case provided by Jiangning Liu who also
brought the issue to light.
llvm-svn: 203762
It seems gas can't handle CFI directives with VFP register names ("d12", etc.).
This broke us trying to build Chromium for Android after 201423.
A gas bug has been filed: https://sourceware.org/bugzilla/show_bug.cgi?id=16694
compnerd suggested making this conditional on whether we're using the integrated
assembler or not. I'll look into that in a follow-up patch.
Differential Revision: http://llvm-reviews.chandlerc.com/D3049
llvm-svn: 203635
This commit moves getSLEB128Size() and getULEB128Size() from
MCAsmInfo to LEB128.h and removes some copy-and-paste code.
Besides, this commit also adds some unit tests for the LEB128
functions.
llvm-svn: 201937
Summary:
AsmPrinter::EmitInlineAsm() will no longer use the EmitRawText() call for
targets with mature MC support. Such targets will always parse the inline
assembly (even when emitting assembly). Targets without mature MC support
continue to use EmitRawText() for assembly output.
The hasRawTextSupport() check in AsmPrinter::EmitInlineAsm() has been replaced
with MCAsmInfo::UseIntegratedAs which when true, causes the integrated assembler
to parse inline assembly (even when emitting assembly output). UseIntegratedAs
is set to true for targets that consider any failure to parse valid assembly
to be a bug. Target specific subclasses generally enable the integrated
assembler in their constructor. The default value can be overridden with
-no-integrated-as.
All tests that rely on inline assembly supporting invalid assembly (for example,
those that use mnemonics such as 'foo' or 'hello world') have been updated to
disable the integrated assembler.
Changes since review (and last commit attempt):
- Fixed test failures that were missed due to configuration of local build.
(fixes crash.ll and a couple others).
- Fixed tests that happened to pass because the local build was on X86
(should fix 2007-12-17-InvokeAsm.ll)
- mature-mc-support.ll's should no longer require all targets to be compiled.
(should fix ARM and PPC buildbots)
- Object output (-filetype=obj and similar) now forces the integrated assembler
to be enabled regardless of default setting or -no-integrated-as.
(should fix SystemZ buildbots)
Reviewers: rafael
Reviewed By: rafael
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2686
llvm-svn: 201333
Summary:
AsmPrinter::EmitInlineAsm() will no longer use the EmitRawText() call for targets with mature MC support. Such targets will always parse the inline assembly (even when emitting assembly). Targets without mature MC support continue to use EmitRawText() for assembly output.
The hasRawTextSupport() check in AsmPrinter::EmitInlineAsm() has been replaced with MCAsmInfo::UseIntegratedAs which when true, causes the integrated assembler to parse inline assembly (even when emitting assembly output). UseIntegratedAs is set to true for targets that consider any failure to parse valid assembly to be a bug. Target specific subclasses generally enable the integrated assembler in their constructor. The default value can be overridden with -no-integrated-as.
All tests that rely on inline assembly supporting invalid assembly (for example, those that use mnemonics such as 'foo' or 'hello world') have been updated to disable the integrated assembler.
Reviewers: rafael
Reviewed By: rafael
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2686
llvm-svn: 201237
In Thumb1 mode, bl instruction might be selected for branches between
basic blocks in the function if the offset is greater than 2KB.
However, this might cause SEGV because the destination symbol
is not marked as thumb function and the execution mode will be reset
to ARM mode.
Since we are sure that these symbols are in the same data fragment, we
can simply resolve these local symbols, and don't emit any relocation
information for this bl instruction.
llvm-svn: 200842
This patch fixes the ldr-pseudo implementation to work when used in
inline assembly. The fix is to move arm assembler constant pools
from the ARMAsmParser class to the ARMTargetStreamer class.
Previously we kept the assembler generated constant pools in the
ARMAsmParser object. This does not work for inline assembly because
a new parser object is created for each blob of inline assembly.
This patch moves the constant pools to the ARMTargetStreamer class
so that the constant pool will remain alive for the entire code
generation process.
An ARMTargetStreamer class is now required for the arm backend.
There was no existing implementation for MachO, only Asm and ELF.
Instead of creating an empty MachO subclass, we decided to make the
ARMTargetStreamer a non-abstract class and provide default
(llvm_unreachable) implementations for the non constant-pool related
methods.
Differential Revision: http://llvm-reviews.chandlerc.com/D2638
llvm-svn: 200777
The .object_arch directive indicates an alternative architecture to be specified
in the object file. The directive does *not* effect the enabled feature bits
for the object file generation. This is particularly useful when the code
performs runtime detection and would like to indicate a lower architecture as
the requirements than the actual instructions used.
llvm-svn: 200451
.movsp is an ARM unwinding directive that indicates to the unwinder that a
register contains an offset from the current stack pointer. If the offset is
unspecified, it defaults to zero.
llvm-svn: 200449
This enhances the ARMAsmParser to handle .tlsdescseq directives. This is a
slightly special relocation. We must be able to generate them, but not consume
them in assembly. The relocation is meant to assist the linker in generating a
TLS descriptor sequence. The ELF target streamer is enhanced to append
additional fixups into the current segment and that is used to emit the new
R_ARM_TLS_DESCSEQ relocations.
llvm-svn: 200448
Add support for tlsdesc relocations which are part of the ABI, marked as
experimental. These relocations permit the linker to perform TLS reference
optimizations.
llvm-svn: 200447
This adds support for TLS CALL relocations. TLS CALL relocations are used to
indicate to the linker to generate appropriate entries to resolve TLS references
via an appropriate function invocation (e.g. __tls_get_addr(PLT)).
In order to accomodate the linker relaxation of the TLS access model for the
references (GD/LD -> IE, IE -> LE), the relocation addend must be incomplete.
This requires that the partial inplace value is also incomplete (i.e. 0). We
simply avoid the offset value calculation at the time of the fixup adjustment in
the ARM assembler backend.
llvm-svn: 200446
After all hard work to implement the EHABI and with the test-suite
passing, it's time to turn it on by default and allow users to
disable it as a work-around while we fix the eventual bugs that show
up.
This commit also remove the -arm-enable-ehabi-descriptors, since we
want the tables to be printed every time the EHABI is turned on
for non-Darwin ARM targets.
Although MCJIT EHABI is not working yet (needs linking with the right
libraries), this commit also fixes some relocations on MCJIT regarding
the EH tables/lib calls, and update some tests to avoid using EH tables
when none are needed.
The EH tests in the test-suite that were previously disabled on ARM
now pass with these changes, so a follow-up commit on the test-suite
will re-enable them.
llvm-svn: 200388
The subtarget info is explicitly passed to the EncodeInstruction
method and we should use that subtarget info to influence any
encoding decisions.
llvm-svn: 200350
This brings MC into line with GNU 'as' on ARM, and it brings the ARM
target into line with most other LLVM targets, which declare the
initial CFI state with addInitialFrameState().
Without this, functions generated with .cfi_startproc/endproc on ARM
will tend to cause GDB to abort with:
gdb/dwarf2-frame.c:1132: internal-error: Unknown CFA rule.
I've also tested this by comparing the output of "readelf -w" on the
object files produced by llvm-mc and gas when given the .s file added
here.
This change is part of addressing PR18636.
Differential Revision: http://llvm-reviews.chandlerc.com/D2597
llvm-svn: 200255
This has a few advantages:
* Only targets that use a MCTargetStreamer have to worry about it.
* There is never a MCTargetStreamer without a MCStreamer, so we can use a
reference.
* A MCTargetStreamer can talk to the MCStreamer in its constructor.
llvm-svn: 200129
There is no inline asm in a .s file. Therefore, there should be no logic to
handle it in the streamer. Inline asm only exists in bitcode files, so the
logic can live in the (long misnamed) AsmPrinter class.
llvm-svn: 200011
This patch restores the ARM mode if the user's inline assembly
does not. In the object streamer, it ensures that instructions
following the inline assembly are encoded correctly and that
correct mapping symbols are emitted. For the asm streamer, it
emits a .arm or .thumb directive.
This patch does not ensure that the inline assembly contains
the ADR instruction to switch modes at runtime.
The problem we need to solve is code like this:
int foo(int a, int b) {
int r = a + b;
asm volatile(
".align 2 \n"
".arm \n"
"add r0,r0,r0 \n"
: : "r"(r));
return r+1;
}
If we compile this function in thumb mode then the inline assembly
will switch to arm mode. We need to make sure that we switch back to
thumb mode after emitting the inline assembly or we will incorrectly
encode the instructions that follow (i.e. the assembly instructions
for return r+1).
Based on patch by David Peixotto
Change-Id: Ib57f6d2d78a22afad5de8693fba6230ff56ba48b
llvm-svn: 199818
This implements the unwind_raw directive for the ARM IAS. The unwind_raw
directive takes the form of a stack offset value followed by one or more bytes
representing the opcodes to be emitted. The opcode emitted will interpreted as
if it were assembled by the opcode assembler via the standard unwinding
directives.
Thanks to Logan Chien for an extra test!
llvm-svn: 199707
The .personalityindex directive is equivalent to the .personality directive with
the ARM EABI personality with the specific index (0, 1, 2). Both of these
directives indicate personality routines, so enhance the personality directive
handling to take into account personalityindex.
Bonus fix: flush the UnwindContext at the beginning of a new function.
Thanks to Logan Chien for additional tests!
llvm-svn: 199706
Ensure that the tag types are reflected on a replacement. This is particularly
important for the compatibility tag which has multiple representations where the
last definition wins.
llvm-svn: 199577
This moves the ARM build attributes definitions and support routines into the
Support library. The support routines simply permit the conversion of the value
to and from a string representation.
The movement is prompted in order to permit access to the constants and string
representations from readobj in order to facilitate decoding of the attributes
section.
llvm-svn: 199575
This will allow it to be called from target independent parts of the main
streamer that don't know if there is a registered target streamer or not. This
in turn will allow targets to perform extra actions at specified points in the
interface: add extra flags for some labels, extra work during finalization, etc.
llvm-svn: 199174
A 32-bit immediate value can be formed from a constant expression and loaded
into a register. Add support to emit this into an object file. Because this
value is a constant, a relocation must *not* be produced for it.
llvm-svn: 199023
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.
Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.
llvm-svn: 198685
Parse tag names as well as expressions. The former is part of the
specification, the latter is for improved compatibility with the GNU assembler.
Fix attribute value handling to be comformant to the specification.
llvm-svn: 198662
The ARM backend has been using most of the MachO related subtarget
checks almost interchangeably, and since the only target it's had to
run on has been IOS (which is all three of MachO, Darwin and IOS) it's
worked out OK so far.
But we'd like to support embedded targets under the "*-*-none-macho"
triple, which means everything starts falling apart and inconsistent
behaviours emerge.
This patch should pick a reasonably sensible set of behaviours for the
new triple (and any others that come along, with luck). Some choices
were debatable (notably FP == r7 or r11), but we can revisit those
later when deficiencies become apparent.
llvm-svn: 198617
Move the ARM EHABI unwind opcode definitions from the ARM MCTargetDesc into LLVM
Support. This enables sharing of the definitions across the ARM target code as
well as llvm-readobj. This will allow implementation of the unwind decoding in
llvm-readobj.
llvm-svn: 198576
Craig Topper