Commit Graph

491 Commits

Author SHA1 Message Date
Xiangling Liao 3b808fb330 [AIX]Emit function descriptor csect in assembly
This patch emits the function descriptor csect for functions with definitions
under both 32-bit/64-bit mode on AIX.

Differential Revision: https://reviews.llvm.org/D66724

llvm-svn: 373009
2019-09-26 19:38:32 +00:00
Pavel Labath aaff1a631a MCRegisterInfo: Merge getLLVMRegNum and getLLVMRegNumFromEH
Summary:
The functions different in two ways:
- getLLVMRegNum could return both "eh" and "other" dwarf register
  numbers, while getLLVMRegNumFromEH only returned the "eh" number.
- getLLVMRegNum asserted if the register was not found, while the second
  function returned -1.

The second distinction was pretty important, but it was very hard to
infer that from the function name. Aditionally, for the use case of
dumping dwarf expressions, we needed a function which can work with both
kinds of number, but does not assert.

This patch solves both of these issues by merging the two functions into
one, returning an Optional<unsigned> value. While the same thing could
be achieved by adding an "IsEH" argument to the (renamed)
getLLVMRegNumFromEH function, it seemed better to avoid the confusion of
two functions and put the choice of asserting into the hands of the
caller -- if he checks the Optional value, he can safely process
"untrusted" input, and if he blindly dereferences the Optional, he gets
the assertion.

I've updated all call sites to the new API, choosing between the two
options according to the function they were calling originally, except
that I've updated the usage in DWARFExpression.cpp to use the "safe"
method instead, and added a test case which would have previously
triggered an assertion failure when processing (incorrect?) dwarf
expressions.

Reviewers: dsanders, arsenm, JDevlieghere

Subscribers: wdng, aprantl, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67154

llvm-svn: 372710
2019-09-24 09:31:02 +00:00
Reid Kleckner 657a06c619 [MC] Avoid crashes from improperly nested or wrong target .seh_handlerdata directives
llvm-svn: 370540
2019-08-30 22:25:55 +00:00
Reid Kleckner a33474d595 [X86] Print register names in .seh_* directives
Also improve assembler parser register validation for .seh_ directives.
This requires moving X86-specific seh directive handling into the x86
backend, which addresses some assembler FIXMEs.

Differential Revision: https://reviews.llvm.org/D66625

llvm-svn: 370533
2019-08-30 21:23:05 +00:00
Xing Xue ef039a3ccd [PowerPC][AIX] Adds support for writing the .data section in assembly files
Summary:
Adds support for generating the .data section in assembly files for global variables with a non-zero initialization. The support for writing the .data section in XCOFF object files will be added in a follow-on patch. Any relocations are not included in this patch.

Reviewers: hubert.reinterpretcast, sfertile, jasonliu, daltenty, Xiangling_L

Reviewed by: hubert.reinterpretcast

Subscribers: nemanjai, hiraditya, kbarton, MaskRay, jsji, wuzish, shchenz, DiggerLin, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66154

llvm-svn: 369869
2019-08-25 15:17:25 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
David Tenty 9bf01e53a3 [NFC][AIX] Use assert instead of llvm_unreachable
Addresses post-commit comments on https://reviews.llvm.org/D64825. Use
assert instead of llvm_unreachable to check if invalid csect types are being
generated. Use report_fatal_error on unimplemented XCOFF features.

Differential Revision: https://reviews.llvm.org/D64825

llvm-svn: 368720
2019-08-13 17:04:51 +00:00
David Tenty 8558aac82c Enable assembly output of local commons for AIX
Summary:
This patch enable assembly output of local commons for AIX using .lcomm
directives. Adds a EmitXCOFFLocalCommonSymbol to MCStreamer so we can emit the
AIX version of .lcomm assembly directives which include a csect name. Handle the
case of BSS locals in PPCAIXAsmPrinter by using EmitXCOFFLocalCommonSymbol. Adds
a test for generating .lcomm on AIX Targets.

Reviewers: cebowleratibm, hubert.reinterpretcast, Xiangling_L, jasonliu, sfertile

Reviewed By: sfertile

Subscribers: wuzish, nemanjai, hiraditya, kbarton, MaskRay, jsji, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64825

llvm-svn: 368306
2019-08-08 15:40:35 +00:00
Nilanjana Basu da60fc813c Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367867
2019-08-05 14:16:58 +00:00
Nilanjana Basu b5e4d7de17 Revert "Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability"
This reverts commit a885afa9fa.

llvm-svn: 367861
2019-08-05 13:55:21 +00:00
Nilanjana Basu a885afa9fa Changing representation of .cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367850
2019-08-05 13:11:51 +00:00
Eric Christopher 5fb56b1966 Temporarily Revert "Changing representation of cv_def_range directives in Codeview debug info assembly format for better readability"
This is breaking bots and the author asked me to revert.

This reverts commit 367704.

llvm-svn: 367707
2019-08-02 19:10:37 +00:00
Nilanjana Basu 1c67521591 Changing representation of cv_def_range directives in Codeview debug info assembly format for better readability
llvm-svn: 367704
2019-08-02 18:44:39 +00:00
Nilanjana Basu 4e22770219 Changes to display code view debug info type records in hex format
llvm-svn: 366390
2019-07-17 23:43:58 +00:00
Alex Lorenz 6d187f0eff [macCatalyst] Use macCatalyst pretty name in .build_version darwin
assembly command

'macCatalyst' is more readable than 'maccatalyst'. I renamed the objdump output,
but the assembly should match it as well.

llvm-svn: 365964
2019-07-12 22:06:08 +00:00
Alex Lorenz da1dfecd32 Add support for the 'macCatalyst' MachO platform
Mac Catalyst is a new MachO platform in macOS Catalina.
It always uses the build_version MachO load command.

Differential Revision: https://reviews.llvm.org/D64107

llvm-svn: 364981
2019-07-02 23:47:11 +00:00
Ali Tamur 783d84bb39 [llvm] Prevent duplicate files in debug line header in dwarf 5: another attempt
Another attempt to land the changes in debug line header to prevent duplicate
files in Dwarf 5. I rolled back my previous commit because of a mistake in
generating the object file in a test. Meanwhile, I addressed some offline
comments and changed the implementation; the largest difference is that
MCDwarfLineTableHeader does not keep DwarfVersion but gets it as a parameter. I
also merged the patch to fix two lld tests that will strt to fail into this
patch.

Original Commit:

https://reviews.llvm.org/D59515

Original Message:
Motivation: In previous dwarf versions, file name indexes started from 1, and
the primary source file was not explicit. Dwarf 5 standard (6.2.4) prescribes
the primary source file to be explicitly given an entry with an index number 0.

The current implementation honors the specification by just duplicating the
main source file, once with index number 0, and later maybe with another
index number. While this is compliant with the letter of the standard, the
duplication causes problems for consumers of this information such as lldb.
(Some files are duplicated, where only some of them have a line table although
all refer to the same file)

With this change, dwarf 5 debug line section files always start from 0, and
the zeroth entry is not duplicated whenever possible. This requires different
handling of dwarf 4 and dwarf 5 during generation (e.g. when a function returns
an index zero for a file name, it signals an error in dwarf 4, but not in dwarf
5) However, I think the minor complication is worth it, because it enables all
consumers (lldb, gdb, dwarfdump, objdump, and so on) to treat all files in the
file name list homogenously.

llvm-svn: 358732
2019-04-19 02:26:56 +00:00
Ali Tamur 59a0e04701 [llvm] Non-functional change: declared a local variable as const.
llvm-svn: 358120
2019-04-10 18:30:03 +00:00
Eric Christopher 798e83b5d6 NFC: Move API uses of MD5::MD5Result to Optional rather than a pointer.
Differential Revision: https://reviews.llvm.org/D60290

llvm-svn: 357736
2019-04-04 23:34:38 +00:00
Andrea Di Biagio edbf06a767 [AsmPrinter] Remove hidden flag -print-schedule.
This patch removes hidden codegen flag -print-schedule effectively reverting the
logic originally committed as r300311
(https://llvm.org/viewvc/llvm-project?view=revision&revision=300311).

Flag -print-schedule was originally introduced by r300311 to address PR32216
(https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better
testing of schedule model instruction latencies/throughputs".

These days, we can use llvm-mca to test scheduling models. So there is no longer
a need for flag -print-schedule in LLVM. The main use case for PR32216 is
now addressed by llvm-mca.
Flag -print-schedule is mainly used for debugging purposes, and it is only
actually used by x86 specific tests. We already have extensive (latency and
throughput) tests under "test/tools/llvm-mca" for X86 processor models. That
means, most (if not all) existing -print-schedule tests for X86 are redundant.

When flag -print-schedule was first added to LLVM, several files had to be
modified; a few APIs gained new arguments (see for example method
MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained
a couple of getSchedInfoStr() methods.

Method getSchedInfoStr() had to originally work for both MCInst and
MachineInstr. The original implmentation of getSchedInfoStr() introduced a
subtle layering violation (reported as PR37160 and then fixed/worked-around by
r330615).
In retrospect, that new API could have been designed more optimally. We can
always query MCSchedModel to get the latency and throughput. More importantly,
the "sched-info" string should not have been generated by the subtarget.
Note, r317782 fixed an issue where "print-schedule" didn't work very well in the
presence of inline assembly. That commit is also reverted by this change.

Differential Revision: https://reviews.llvm.org/D57244

llvm-svn: 353043
2019-02-04 12:51:26 +00:00
Vedant Kumar 13ef84fced [MC] Teach the MachO object writer about N_FUNC_COLD
N_FUNC_COLD is a new MachO symbol attribute. It's a hint to the linker
to order a symbol towards the end of its section, to improve locality.

Example:

```
void a1() {}
__attribute__((cold)) void a2() {}
void a3() {}
int main() {
  a1();
  a2();
  a3();
  return 0;
}
```

A linker that supports N_FUNC_COLD will order _a2 to the end of the text
section. From `nm -njU` output, we see:

```
_a1
_a3
_main
_a2
```

Differential Revision: https://reviews.llvm.org/D57190

llvm-svn: 352227
2019-01-25 18:30:22 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Luke Cheeseman 41a9e53500 [Dwarf/AArch64] Return address signing B key dwarf support
- When signing return addresses with -msign-return-address=<scope>{+<key>},
  either the A key instructions or the B key instructions can be used. To
  correctly authenticate the return address, the unwinder/debugger must know
  which key was used to sign the return address.
- When and exception is thrown or a break point reached, it may be necessary to
  unwind the stack. To accomplish this, the unwinder/debugger must be able to
  first authenticate an the return address if it has been signed.
- To enable this, the augmentation string of CIEs has been extended to allow
  inclusion of a 'B' character. Functions that are signed using the B key
  variant of the instructions should have and FDE whose associated CIE has a 'B'
  in the augmentation string.
- One must also be able to preserve these semantics when first stepping from a
  high level language into assembly and then, as a second step, into an object
  file. To achieve this, I have introduced a new assembly directive
  '.cfi_b_key_frame ', that tells the assembler the current frame uses return
  address signing with the B key.
- This ensures that the FDE is associated with a CIE that has 'B' in the
  augmentation string.

Differential Revision: https://reviews.llvm.org/D51798

llvm-svn: 349895
2018-12-21 10:45:08 +00:00
Michael Trent f44d830e2d Add PLATFORM constants for iOS, tvOS, and watchOS simulators
Summary:
Add PLATFORM constants for iOS, tvOS, and watchOS simulators, as well
as human readable names for these constants, to the Mach-O file format
header files. 

rdar://46854119

Reviewers: ab, davide

Reviewed By: ab, davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D55905

llvm-svn: 349779
2018-12-20 17:51:17 +00:00
Luke Cheeseman f57d7d8237 [AArch64] - Return address signing dwarf support
- Reapply changes intially introduced in r343089
- The archtecture info is no longer loaded whenever a DWARFContext is created
- The runtimes libraries (santiziers) make use of the dwarf context classes but
  do not intialise the target info
- The architecture of the object can be obtained without loading the target info
- Adding a method to the dwarf context to get this information and multiplex the
  string printing later on

Differential Revision: https://reviews.llvm.org/D55774

llvm-svn: 349472
2018-12-18 10:37:42 +00:00
Alex Lorenz afa75d7843 [macho] save the SDK version stored in module metadata into the version min and
build version load commands in the object file

This commit introduces a new metadata node called "SDK Version". It will be set
by the frontend to mark the platform SDK (macOS/iOS/etc) version which was used
during that particular compilation.
This node is used when machine code is emitted, by either saving the SDK version
into the appropriate macho load command (version min/build version), or by
emitting the assembly for these load commands with the SDK version specified as
well.
The assembly for both load commands is extended by allowing it to contain the
sdk_version X, Y [, Z] trailing directive to represent the SDK version
respectively.

rdar://45774000

Differential Revision: https://reviews.llvm.org/D55612

llvm-svn: 349119
2018-12-14 01:14:10 +00:00
Luke Cheeseman 6db3a6a4a7 Revert r347490 as it breaks address sanitizer builds
llvm-svn: 347499
2018-11-23 17:13:06 +00:00
Luke Cheeseman d6dbd64104 Revert r343341
- Cannot reproduce the build failure locally and the build logs have
  been deleted.

llvm-svn: 347490
2018-11-23 11:01:47 +00:00
Sanjin Sijaric 96f2ea3dd4 [ARM64][Windows] MCLayer support for exception handling
Add ARM64 unwind codes to MCLayer, as well SEH directives that will be emitted
by the frame lowering patch to follow.  We only emit unwind codes into object
object files for now.

Differential Revision: https://reviews.llvm.org/D50166

llvm-svn: 345450
2018-10-27 06:13:06 +00:00
Alexey Bataev c15c853c3a [DEBUGINFO, NVPTX] Try to pack bytes data into a single string.
Summary:
If the target does not support `.asciz` and `.ascii` directives, the
strings are represented as bytes and each byte is placed on the new line
as a separate byte directive `.b8 <data>`. NVPTX target allows to
represent the vector of the data of the same type as a vector, where
values are separated using `,` symbol: `.b8 <data1>,<data2>,...`. This
allows to reduce the size of the final PTX file. Ptxas tool includes ptx
files into the resulting binary object, so reducing the size of the PTX
file is important.

Reviewers: tra, jlebar, echristo

Subscribers: jholewinski, llvm-commits

Differential Revision: https://reviews.llvm.org/D45822

llvm-svn: 345142
2018-10-24 14:04:00 +00:00
Luke Cheeseman 10981cc884 Revert r343317
- asan buildbots are breaking and I need to investigate the issue

llvm-svn: 343341
2018-09-28 17:01:50 +00:00
Luke Cheeseman 21f2955bb2 Reapply changes reverted by r343235
- Add fix so that all code paths that create DWARFContext
  with an ObjectFile initialise the target architecture in the context
- Add an assert that the Arch is known in the Dwarf CallFrameString method

llvm-svn: 343317
2018-09-28 13:37:27 +00:00
Luke Cheeseman 8e5676b1aa Revert r343192 as an ubsan build is currently failing
llvm-svn: 343235
2018-09-27 16:47:30 +00:00
Luke Cheeseman f6844b307a Reapply changes reverted in r343114, lldb patch to follow shortly
llvm-svn: 343192
2018-09-27 10:39:20 +00:00
Luke Cheeseman 77aaa22081 Revert r343112 as CallFrameString API change has broken lldb builds
llvm-svn: 343114
2018-09-26 14:48:03 +00:00
Luke Cheeseman 03ad8812f5 [AArch64] - Return address signing dwarf support
- Reapply r343089 with a fix for DebugInfo/Sparc/gnu-window-save.ll

llvm-svn: 343112
2018-09-26 14:30:29 +00:00
Hans Wennborg 00b88bbcaf Revert r343089 "[AArch64] - Return address signing dwarf support"
This caused the DebugInfo/Sparc/gnu-window-save.ll test to fail.

> Functions that have signed return addresses need additional dwarf support:
> - After signing the LR, and before authenticating it, the LR register is in a
>   state the is unusable by a debugger or unwinder
> - To account for this a new directive, .cfi_negate_ra_state, is added
> - This directive says the signed state of the LR register has now changed,
>   i.e. unsigned -> signed or signed -> unsigned
> - This directive has the same CFA code as the SPARC directive GNU_window_save
>   (0x2d), adding a macro to account for multiply defined codes
> - This patch matches the gcc implementation of this support:
>   https://patchwork.ozlabs.org/patch/800271/
>
> Differential Revision: https://reviews.llvm.org/D50136

llvm-svn: 343103
2018-09-26 12:57:45 +00:00
Luke Cheeseman f755e687fc [AArch64] - Return address signing dwarf support
Functions that have signed return addresses need additional dwarf support:
- After signing the LR, and before authenticating it, the LR register is in a
  state the is unusable by a debugger or unwinder
- To account for this a new directive, .cfi_negate_ra_state, is added
- This directive says the signed state of the LR register has now changed,
  i.e. unsigned -> signed or signed -> unsigned
- This directive has the same CFA code as the SPARC directive GNU_window_save
  (0x2d), adding a macro to account for multiply defined codes
- This patch matches the gcc implementation of this support:
  https://patchwork.ozlabs.org/patch/800271/

Differential Revision: https://reviews.llvm.org/D50136

llvm-svn: 343089
2018-09-26 10:14:15 +00:00
Reid Kleckner 689f773317 [codeview] Clean up machinery for deferring .cv_loc emission
Now that we create the label at the point of the directive, we don't
need to set the "current CV location", and then later when we emit the
next instruction, create a label for it and emit it.

DWARF still defers the labels used in .debug_loc until the next
instruction or value, for reasons unknown.

llvm-svn: 340883
2018-08-28 23:25:59 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Martin Storsjo 390bce4322 [MC] Add support for the .rva assembler directive for COFF targets
Even though gas doesn't document it, it has been supported there for
a very long time.

This produces the 32 bit relative virtual address (aka image relative
address) for a given symbol. ".rva foo" is essentially equal to
".long foo@imgrel".

Differential Revision: https://reviews.llvm.org/D49821

llvm-svn: 338063
2018-07-26 20:11:26 +00:00
Michael Kruse 6f1da6e345 [ADT] Replace std::isprint by llvm::isPrint.
The standard library functions ::isprint/std::isprint have platform-
and locale-dependent behavior which makes LLVM's output less
predictable. In particular, regression tests my fail depending on the
implementation of these functions.

Implement llvm::isPrint in StringExtras.h with a standard behavior and
replace all uses of ::isprint/std::isprint by a call it llvm::isPrint.
The function is inlined and does not look up language settings so it
should perform better than the standard library's version.

Such a replacement has already been done for isdigit, isalpha, isxdigit
in r314883. gtest does the same in gtest-printers.cc using the following
justification:

    // Returns true if c is a printable ASCII character.  We test the
    // value of c directly instead of calling isprint(), which is buggy on
    // Windows Mobile.
    inline bool IsPrintableAscii(wchar_t c) {
      return 0x20 <= c && c <= 0x7E;
    }

Similar issues have also been encountered by Julia:
https://github.com/JuliaLang/julia/issues/7416

I noticed the problem myself when on Windows isprint('\t') started to
evaluate to true (see https://stackoverflow.com/questions/51435249) and
thus caused several unit tests to fail. The result of isprint doesn't
seem to be well-defined even for ASCII characters. Therefore I suggest
to replace isprint by a platform-independent version.

Differential Revision: https://reviews.llvm.org/D49680

llvm-svn: 338034
2018-07-26 15:31:41 +00:00
Peter Collingbourne 3e22733698 MC: Implement support for new .addrsig and .addrsig_sym directives.
Part of the address-significance tables proposal:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123514.html

Differential Revision: https://reviews.llvm.org/D47744

llvm-svn: 337328
2018-07-17 22:17:18 +00:00
Francis Visoiu Mistrih 4d5b1073ba [MC] Error on a .zerofill directive in a non-virtual section
On darwin, all virtual sections have zerofill type, and having a
.zerofill directive in a non-virtual section is not allowed. Instead of
asserting, show a nicer error.

In order to use the equivalent of .zerofill in a non-virtual section,
the usage of .zero of .space is required.

This patch replaces the assert with an error.

Differential Revision: https://reviews.llvm.org/D48517

llvm-svn: 336127
2018-07-02 17:29:43 +00:00
Paul Robinson cc7344aae3 [DWARFv5] Tolerate files not all having an MD5 checksum.
In some cases, for example when compiling a preprocessed file, the
front-end is not able to provide an MD5 checksum for all files. When
that happens, omit the MD5 checksums from the final DWARF, because
DWARF doesn't have a way to indicate that some but not all files have
a checksum.

When assembling a .s file, and some but not all .file directives
provide an MD5 checksum, issue a warning and don't emit MD5 into the
DWARF.

Fixes PR37623.

Differential Revision: https://reviews.llvm.org/D48135

llvm-svn: 334710
2018-06-14 13:38:20 +00:00
Peter Smith 57f661bd7d [MC] Pass MCSubtargetInfo to fixupNeedsRelaxation and applyFixup
On targets like Arm some relaxations may only be performed when certain
architectural features are available. As functions can be compiled with
differing levels of architectural support we must make a judgement on
whether we can relax based on the MCSubtargetInfo for the function. This
change passes through the MCSubtargetInfo for the function to
fixupNeedsRelaxation so that the decision on whether to relax can be made
per function. In this patch, only the ARM backend makes use of this
information. We must also pass the MCSubtargetInfo to applyFixup because
some fixups skip error checking on the assumption that relaxation has
occurred, to prevent code-generation errors applyFixup must see the same
MCSubtargetInfo as fixupNeedsRelaxation.

Differential Revision: https://reviews.llvm.org/D44928

llvm-svn: 334078
2018-06-06 09:40:06 +00:00
Nirav Dave 05b589101e [MC][X86] Allow assembler variable assignment to register name.
Summary:
Allow extended parsing of variable assembler assignment syntax and modify X86 to permit
VAR = register assignment. As we emit these as .set directives when possible, we inline
such expressions in output assembly.

Fixes PR37425.

Reviewers: rnk, void, echristo

Reviewed By: rnk

Subscribers: nickdesaulniers, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D47545

llvm-svn: 334022
2018-06-05 15:13:39 +00:00
Michael J. Spencer ae6eeaea92 [MC] Add assembler support for .cg_profile.
Object FIle Representation
At codegen time this is emitted into the ELF file a pair of symbol indices and a weight. In assembly it looks like:

.cg_profile a, b, 32
.cg_profile freq, a, 11
.cg_profile freq, b, 20

When writing an ELF file these are put into a SHT_LLVM_CALL_GRAPH_PROFILE (0x6fff4c02) section as (uint32_t, uint32_t, uint64_t) tuples as (from symbol index, to symbol index, weight).

Differential Revision: https://reviews.llvm.org/D44965

llvm-svn: 333823
2018-06-02 16:33:01 +00:00
Nirav Dave 6c0665e221 [MC] Change AsmParser to leverage Assembler during evaluation
Teach AsmParser to check with Assembler for when evaluating constant
expressions.  This improves the handing of preprocessor expressions
that must be resolved at parse time. This idiom can be found as
assembling-time assertion checks in source-level assemblers. Note that
this relies on the MCStreamer to keep sufficient tabs on Section /
Fragment information which the MCAsmStreamer does not. As a result the
textual output may fail where the equivalent object generation would
pass. This can most easily be resolved by folding the MCAsmStreamer
and MCObjectStreamer together which is planned for in a separate
patch.

Currently, this feature is only enabled for assembly input, keeping IR
compilation consistent between assembly and object generation.

Reviewers: echristo, rnk, probinson, espindola, peter.smith

Reviewed By: peter.smith

Subscribers: eraman, peter.smith, arichardson, jyknight, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45164

llvm-svn: 331218
2018-04-30 19:22:40 +00:00
Nirav Dave 6b01b88012 [MC] Undo spurious commit added into r331052.
llvm-svn: 331055
2018-04-27 16:16:06 +00:00