This option, compatible with gas's -mimplicit-it, controls the
generation/checking of implicit IT blocks in ARM/Thumb assembly.
This option allows two behaviours that were not possible before:
- When in ARM mode, emit a warning when assembling a conditional
instruction that is not in an IT block. This is enabled with
-mimplicit-it=never and -mimplicit-it=thumb.
- When in Thumb mode, automatically generate IT instructions when an
instruction with a condition code appears outside of an IT block. This
is enabled with -mimplicit-it=thumb and -mimplicit-it=always.
The default option is -mimplicit-it=arm, which matches the existing
behaviour (allow conditional ARM instructions outside IT blocks without
warning, and error if a conditional Thumb instruction is outside an IT
block).
The general strategy for generating IT blocks in Thumb mode is to keep a
small list of instructions which should be in the IT block, and only
emit them when we encounter something in the input which means we cannot
continue the block. This could be caused by:
- A non-predicable instruction
- An instruction with a condition not compatible with the IT block
- The IT block already contains 4 instructions
- A branch-like instruction (including ALU instructions with the PC as
the destination), which cannot appear in the middle of an IT block
- A label (branching into an IT block is not legal)
- A change of section, architecture, ISA, etc
- The end of the assembly file.
Some of these, such as change of section and end of file, are parsed
outside of the ARM asm parser, so I've added a new virtual function to
AsmParser to ensure any previously-parsed instructions have been
emitted. The ARM implementation of this flushes the currently pending IT
block.
We now have to try instruction matching up to 3 times, because we cannot
know if the current IT block is valid before matching, and instruction
matching changes depending on the IT block state (due to the 16-bit ALU
instructions, which set the flags iff not in an IT block). In the common
case of not having an open implicit IT block and the instruction being
matched not needing one, we still only have to run the matcher once.
I've removed the ITState.FirstCond variable, because it does not store
any information that isn't already represented by CurPosition. I've also
updated the comment on CurPosition to accurately describe it's meaning
(which this patch doesn't change).
Differential Revision: https://reviews.llvm.org/D22760
llvm-svn: 276747
Add parseToken and compatriot functions to stitch error checks in
straight linear code. As part of this fix some erronous handling of
directives where the EndOfStatement token either was not checked or
Lexed on termination.
Reviewers: rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D22312
llvm-svn: 275795
Preserve assembly comments from input in output assembly and flags to
toggle property. This is on by default for inline assembly and off in
llvm-mc.
Parsed comments are emitted immediately before an EOL which generally
places them on the expected line.
Reviewers: rtrieu, dwmw2, rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20020
llvm-svn: 275058
Recommiting after fixing non-atomic insert to front of SmallVector in
MCAsmLexer.h
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 273007
Add explicit Comment Token in Assembly Lexing for future support for
outputting explicit comments from inline assembly. As part of this,
CPPHash Directives are now explicitly distinguished from Hash line
comments in Lexer.
Line comments are recorded as EndOfStatement tokens, not Comment tokens
to simplify compatibility with current TargetParsers. This slightly
complicates comment output.
This remove all lexing tasks out of the parser, does minor cleanup
to remove extraneous newlines Asm Output, and some improvements white
space handling.
Reviewers: rtrieu, dwmw2, rnk
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20009
llvm-svn: 272953
Do not issue lexing errors found during the parsing of macro body
definitions and parseIdentifier function in AsmParser. This changes the
Parser to not issue a lexing error when we reach an error, but rather
when it is consumed allowing us time to examine and recover from an
error.
As a result, of this, we stop issuing a both lexing error and a parsing
error in floating-literals test. Minor tweak to parseDirectiveRealValue
to favor more meaningful lexing error over less helpful parse error.
Reviewers: rnk, majnemer
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20535
llvm-svn: 271542
Rather than invoking emitFill with negative size, which may trigger
an undefined behavior, return immediately after emitting the warning.
Differential Revision: http://reviews.llvm.org/D20768
llvm-svn: 271107
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20752
llvm-svn: 271102
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20656
llvm-svn: 271028
If there is already debug info in the assembly file, and user hope to
use -g option for compiling, we think we should not directly report an
error.
According to what GNU assembler did, it just reused the debug info in
the assembly file, and turned off the DEBUG_TYPE option so that there
will be no new debug info emitted by assembler. This fix is just as what
GNU assembler did.
The concern is the situation that there are two .text sections in the
assembly file, one with debug info and the other one without. Currently
with this fix, the assembler will no longer generate any debug info for
the second .text section. And this is what GNU assembler exactly did for
this situation. So I think this still make some sense.
Patch by Zhizhou Yang!
Differential Revision: http://reviews.llvm.org/D20002
llvm-svn: 270806
This matches the behavior of GNU assembler which supports symbolic
expressions in absolute expressions used in assembly directives.
Differential Revision: http://reviews.llvm.org/D20337
llvm-svn: 270786
Removed some unused headers, replaced some headers with forward class declarations.
Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'
Patch by Eugene Kosov <claprix@yandex.ru>
Differential Revision: http://reviews.llvm.org/D19219
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
Since we can't emit diagnostics for missing "jmp 1f" labels until the end of
the file, we need to be able to restore the context used to calculate
file/line. This is basically the "# line file" directive that's being used at
the time the expression is seen.
rdar://25706972
llvm-svn: 266238
Before, ELF at least managed a diagnostic but it was a completely untraceable
"undefined symbol" error. MachO had a variety of even worse behaviours: crash,
emit corrupt file, or an equally bad message.
llvm-svn: 265984
Adding support for section names with special characters in them (e.g. "/").
GCC successfully compiles such section names.
This also fixes PR24520.
Differential Revision: http://reviews.llvm.org/D15678
llvm-svn: 264038
This patch adds support for the MachO .alt_entry assembly directive, and uses
it for global aliases with non-zero GEP offsets. The alt_entry flag indicates
that a symbol should be layed out immediately after the preceding symbol.
Conceptually it introduces an alternate entry point for a function or data
structure. E.g.:
safe_foo:
// check preconditions for foo
.alt_entry fast_foo
fast_foo:
// body of foo, can assume preconditions.
The .alt_entry flag is also implicitly set on assembly aliases of the form:
a = b + C
where C is a non-zero constant, since these have the same effect as an
alt_entry symbol: they introduce a label that cannot be moved relative to the
preceding one. Setting the alt_entry flag on aliases of this form fixes
http://llvm.org/PR25381.
llvm-svn: 263521
Until now curly braces could only be used in MS inline assembly to mark block start/end.
All curly braces were removed completely at a very early stage.
This approach caused bugs like:
"m{o}v eax, ebx" turned into "mov eax, ebx" without any error.
In addition, AVX-512 added special operands (e.g., k registers), which are also surrounded by curly braces that mark them as such.
Now, we need to keep the curly braces and identify at a later stage if they are marking block start/end (if so, ignore them), or surrounding special AVX-512 operands (if so, parse them as such).
This patch fixes the bug described above and enables the use of AVX-512 special operands.
This commit is the the llvm part of the patch.
The clang part of the review is: http://reviews.llvm.org/D17766
The llvm part of the review is: http://reviews.llvm.org/D17767
Differential Revision: http://reviews.llvm.org/D17767
llvm-svn: 262843
Summary:
Fixed an issue for mips with an instruction such as 'sdc1 $f1, 272 +8(a0)' which has a space between '272' and '+'. The parser would then parse '272' and '+8' as two arguments instead of a single expression resulting in one too many arguments in the pseudo instruction.
The reason that the test case has been changed is so that the expected
output matches the output of the GNU assembler.
Reviewers: vkalintiris, dsanders
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D13592
llvm-svn: 260521
CodeView, like most other debug formats, represents the live range of a
variable so that debuggers might print them out.
They use a variety of records to represent how a particular variable
might be available (in a register, in a frame pointer, etc.) along with
a set of ranges where this debug information is relevant.
However, the format only allows us to use ranges which are limited to a
maximum of 0xF000 in size. This means that we need to split our debug
information into chunks of 0xF000.
Because the layout of code is not known until *very* late, we must use a
new fragment to record the information we need until we can know
*exactly* what the range is.
llvm-svn: 259868
CodeView requires us to accurately describe the extent of the inlined
code. We did this by grabbing the next debug location in source order
and using *that* to denote where we stopped inlining. However, this is
not sufficient or correct in instances where there is no next debug
location or the next debug location belongs to the start of another
function.
To get this correct, use the end symbol of the function to denote the
last possible place the inlining could have stopped at.
llvm-svn: 259548
This directive emits the binary annotations that describe line and code
deltas in inlined call sites. Single-stepping through inlined frames in
windbg now works.
llvm-svn: 259535
This support is _very_ rudimentary, just enough to get some basic data
into the CodeView debug section.
Left to do is:
- Use the combined opcodes to save space.
- Do something about code offsets.
llvm-svn: 259230
This reverts commit r259117.
The LineInfo constructor is defined in the codeview library and we have
to link against it now. Doing that isn't trivial, so reverting for now.
llvm-svn: 259126
Adds a new family of .cv_* directives to LLVM's variant of GAS syntax:
- .cv_file: Similar to DWARF .file directives
- .cv_loc: Similar to the DWARF .loc directive, but starts with a
function id. CodeView line tables are emitted by function instead of
by compilation unit, so we needed an extra field to communicate this.
Rather than overloading the .loc direction further, we decided it was
better to have our own directive.
- .cv_stringtable: Emits the codeview string table at the current
position. Currently this just contains the filenames as
null-terminated strings.
- .cv_filechecksums: Emits the file checksum table for all files used
with .cv_file so far. There is currently no support for emitting
actual checksums, just filenames.
This moves the line table emission code down into the assembler. This
is in preparation for implementing the inlined call site line table
format. The inline line table format encoding algorithm requires knowing
the absolute code offsets, so it must run after the assembler has laid
out the code.
David Majnemer collaborated on this patch.
llvm-svn: 259117
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi
Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark
Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D16471
llvm-svn: 258861
The .even directive aligns content to an evan-numbered address.
In at&t syntax .even
In Microsoft syntax even (without the dot).
Differential Revision: http://reviews.llvm.org/D15413
llvm-svn: 255462
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.
It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.
There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
linker since it knowns where the dynamic relocations are.
llvm-svn: 253436
This adds reportError to MCContext, which can be used as an alternative to
reportFatalError when the assembler wants to try to continue processing the
rest of the file after the error is reported, so that all of the errors ina
file can be reported. It records the fact that an error was encountered, so we
can avoid emitting an object file if any errors occurred.
This patch doesn't add any uses of this function (a later patch will convert
most uses of reportFatalError to use it), but there is a small functional
change: we use the SourceManager to print the error message, even if we have a
null SMLoc. This means that we get a SourceManager-style message, with the file
and line information shown as <unknown>, rather than the "LLVM ERROR" style
used by report_fatal_error.
llvm-svn: 253327
The way prelink used to work was
* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.
There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
implementation is pretty broken. It talks about relocations that are
"resolved by the static linker". If they are resolved, there are none
left for the prelinker. What one needs to track is if an expression
will require only dynamic relocations that point to the same DSO.
At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)
This patch removes support for it. That is, it stops printing the
".local" sections.
llvm-svn: 253280
MCRelaxableFragment previously kept a copy of MCSubtargetInfo and
MCInst to enable re-encoding the MCInst later during relaxation. A copy
of MCSubtargetInfo (instead of a reference or pointer) was needed
because the feature bits could be modified by the parser.
This commit replaces the MCSubtargetInfo copy in MCRelaxableFragment
with a constant reference to MCSubtargetInfo. The copies of
MCSubtargetInfo are kept in MCContext, and the target parsers are now
responsible for asking MCContext to provide a copy whenever the feature
bits of MCSubtargetInfo have to be toggled.
With this patch, I saw a 4% reduction in peak memory usage when I
compiled verify-uselistorder.lto.bc using llc.
rdar://problem/21736951
Differential Revision: http://reviews.llvm.org/D14346
llvm-svn: 253127
Davide Italiano