Commit Graph

404 Commits

Author SHA1 Message Date
Shiva Chen 5af037f1e9 [RISCV] Insert R_RISCV_ALIGN relocation type and Nops for code alignment when linker relaxation enabled
Linker relaxation may change code size. We need to fix up the alignment
of alignment directive in text section by inserting Nops and R_RISCV_ALIGN
relocation type. So then linker could satisfy the alignment by removing Nops.

To do this:

1. Add shouldInsertExtraNopBytesForCodeAlign target hook to calculate
   the Nops we need to insert.

2. Add shouldInsertFixupForCodeAlign target hook to insert
   R_RISCV_ALIGN fixup type.

Differential Revision: https://reviews.llvm.org/D47755

llvm-svn: 352616
2019-01-30 11:16:59 +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
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
Hsiangkai Wang 2089e4c8f1 [DebugInfo] Fix build failed in clang-x86_64-linux-selfhost-modules.
Only generate symbol difference expression if needed.

llvm-svn: 338484
2018-08-01 04:17:41 +00:00
Hsiangkai Wang 5c63af0d04 [DebugInfo] Generate fixups as emitting DWARF .debug_line.
It is necessary to generate fixups in .debug_line as relaxation is
enabled due to the address delta may be changed after relaxation.

DWARF will record the mappings of lines and addresses in
.debug_line section. It will encode the information using special
opcodes, standard opcodes and extended opcodes in Line Number
Program. I use DW_LNS_fixed_advance_pc to encode fixed length
address delta and DW_LNE_set_address to encode absolute address
to make it possible to generate fixups in .debug_line section.

Differential Revision: https://reviews.llvm.org/D46850

llvm-svn: 338477
2018-08-01 02:18:06 +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
Peter Smith 1503fc0fd0 [MC] Move bundling and MCSubtargetInfo to MCEncodedFragment [NFC]
Instruction bundling is only supported on descendants of the
MCEncodedFragment type. By moving the bundling functionality and
MCSubtargetInfo to this class it makes it easier to set and extract the
MCSubtargetInfo when it is necessary.

This is a refactoring change that will make it easier to pass the
MCSubtargetInfo through to writeNops when nop padding is required.

Differential Revision: https://reviews.llvm.org/D45959

llvm-svn: 334814
2018-06-15 09:48:18 +00:00
Sam Clegg 8c32e913b5 [MC] Move MCAssembler::dump into the correct cpp file. NFC
Differential Revision: https://reviews.llvm.org/D46556

llvm-svn: 334713
2018-06-14 14:04:23 +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
Alex Bradbury 257d5b5639 [RISCV] Add symbol diff relocation support for RISC-V
For RISC-V it is desirable to have relaxation happen in the linker once 
addresses are known, and as such the size between two instructions/byte 
sequences in a section could change.

For most assembler expressions, this is fine, as the absolute address results 
in the expression being converted to a fixup, and finally relocations. 
However, for expressions such as .quad .L2-.L1, the assembler folds this down 
to a constant once fragments are laid out, under the assumption that the 
difference can no longer change, although in the case of linker relaxation the 
differences can change at link time, so the constant is incorrect. One place 
where this commonly appears is in debug information, where the size of a 
function expression is in a form similar to the above.

This patch extends the assembler to allow an AsmBackend to declare that it 
does not want the assembler to fold down this expression, and instead generate 
a pair of relocations that allow the linker to carry out the calculation. In 
this case, the expression is not folded, but when it comes to emitting a 
fixup, the generic FK_Data_* fixups are converted into a pair, one for the 
addition half, one for the subtraction, and this is passed to the relocation 
generating methods as usual. I have named these FK_Data_Add_* and 
FK_Data_Sub_* to indicate which half these are for.

For RISC-V, which supports this via e.g. the R_RISCV_ADD64, R_RISCV_SUB64 pair 
of relocations, these are also set to always emit relocations relative to 
local symbols rather than section offsets. This is to deal with the fact that 
if relocations were calculated on e.g. .text+8 and .text+4, the result 12 
would be stored rather than 4 as both addends are added in the linker.

Differential Revision: https://reviews.llvm.org/D45181
Patch by Simon Cook.

llvm-svn: 333079
2018-05-23 12:36:18 +00:00
Peter Collingbourne 438390fae1 MC: Have the object writers return the number of bytes written. NFCI.
This removes the last external use of the stream.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47042

llvm-svn: 332863
2018-05-21 18:23:50 +00:00
Peter Collingbourne 147db3e628 MC: Change MCAssembler::writeSectionData and writeFragmentPadding to take a raw_ostream. NFCI.
Also clean up a couple of hacks where we were writing the section
contents to another stream by setting the object writer's stream,
writing and setting it back.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47038

llvm-svn: 332858
2018-05-21 18:11:35 +00:00
Peter Collingbourne 571a3301ae MC: Change MCAsmBackend::writeNopData() to take a raw_ostream instead of an MCObjectWriter. NFCI.
To make this work I needed to add an endianness field to MCAsmBackend
so that writeNopData() implementations know which endianness to use.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47035

llvm-svn: 332857
2018-05-21 17:57:19 +00:00
Nirav Dave 588fad4d3b [MC] Relax .fill size requirements
Avoid requirement that number of values must be known at assembler
time.

Fixes PR33586.

Reviewers: rnk, peter.smith, echristo, jyknight

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D46703

llvm-svn: 332741
2018-05-18 17:45:48 +00:00
Shiva Chen 6e07dfb148 [RISCV] Add WasForced parameter to MCAsmBackend::fixupNeedsRelaxationAdvanced
For RISCV branch instructions, we need to preserve relocation types when linker
relaxation enabled, so then linker could modify offset when the branch offsets
changed.

We preserve relocation types by define shouldForceRelocation.
IsResolved return by evaluateFixup will always false when shouldForceRelocation
return true. It will make RISCV MC Branch Relaxation always relax 16-bit
branches to 32-bit form, even if the symbol actually could be resolved.

To avoid 16-bit branches always relax to 32-bit form when linker relaxation
enabled, we add a new parameter WasForced to indicate that the symbol actually
couldn't be resolved and not forced by shouldForceRelocation return true.

RISCVAsmBackend::fixupNeedsRelaxationAdvanced could relax branches with
unresolved symbols by (!IsResolved && !WasForced).

RISCV MC Branch Relaxation is needed because RISCV could perform 32-bit
to 16-bit transformation in MC layer.

Differential Revision: https://reviews.llvm.org/D46350

llvm-svn: 332696
2018-05-18 06:42:21 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Nirav Dave 38b4b54a2c [MC] Provide default value for IsResolved.
llvm-svn: 331052
2018-04-27 16:11:24 +00:00
Nirav Dave 1b5533c9e8 [MC] Modify MCAsmStreamer to always build MCAssembler. NFCI.
llvm-svn: 331048
2018-04-27 15:45:54 +00:00
Nirav Dave 8728e097df [MC] Allow MCAssembler to be constructed without all subcomponents. NFCI.
llvm-svn: 331047
2018-04-27 15:45:27 +00:00
Rafael Espindola 45b12f1835 [MC] Fix assembler infinite loop on EH table using LEB padding.
Fix the infinite loop reported in PR35809. It can occur with GCC-style
EH table assembly, where the compiler relies on the assembler to
calculate the offsets in the EH table.

Also see https://sourceware.org/bugzilla/show_bug.cgi?id=4029 for the
equivalent issue in the GNU assembler.

Patch by Ryan Prichard!

llvm-svn: 323934
2018-02-01 00:25:19 +00:00
Rafael Espindola d707c37072 Use a MCExpr for the size of MCFillFragment.
This allows the size to be found during ralaxation. This fixes
pr35858.

llvm-svn: 322131
2018-01-09 22:48:37 +00:00
Matthias Braun 0148c88c08 MC: Add support for mach-o build_version
LC_BUILD_VERSION is a new load command superseding the previously used
LC_XXX_MIN_VERSION commands. This adds an assembler directive along with
encoding/streaming support.

llvm-svn: 320661
2017-12-14 00:12:46 +00:00
Adrian McCarthy 75248a7ade NFC: Rename MCSafeSEHFragment to MCSymbolIdFragment
Summary:
This fragment emits a symbol ID and will be useful for more than just Safe SEH
tables (e.g., I plan to re-use it for Control Flow Guard tables).  This is
simply a rename refactor.

Reviewers: rnk

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D39770

llvm-svn: 317703
2017-11-08 18:57:02 +00:00
Omer Paparo Bivas 2251c79aba [MC] Adding code padding for performance stability - infrastructure. NFC.
Infrastructure designed for padding code with nop instructions in key places such that preformance improvement will be achieved.
The infrastructure is implemented such that the padding is done in the Assembler after the layout is done and all IPs and alignments are known.
This patch by itself in a NFC. Future patches will make use of this infrastructure to implement required policies for code padding.

Reviewers:
aaboud
zvi
craig.topper
gadi.haber

Differential revision: https://reviews.llvm.org/D34393

Change-Id: I92110d0c0a757080a8405636914a93ef6f8ad00e
llvm-svn: 316413
2017-10-24 06:16:03 +00:00
Rafael Espindola ceecfe5be2 Simplify interface now that we don't need to pass IsPCRel. NFC.
llvm-svn: 307734
2017-07-11 23:56:10 +00:00
Rafael Espindola 1beb702ba2 Fully fix the movw/movt addend.
The issue is not if the value is pcrel. It is whether we have a
relocation or not.

If we have a relocation, the static linker will select the upper
bits. If we don't have a relocation, we have to do it.

llvm-svn: 307730
2017-07-11 23:18:25 +00:00
Rafael Espindola 76287ab3a0 Rename and adjust processFixupValue.
It was not processing any value. All that it ever did was force
relocations, so name it shouldForceRelocation.

llvm-svn: 306906
2017-06-30 22:47:27 +00:00
Rafael Espindola 6418856127 Simplify the processFixupValue interface. NFC.
llvm-svn: 306202
2017-06-24 05:22:28 +00:00
Rafael Espindola f351292141 Remove redundant argument.
llvm-svn: 306189
2017-06-24 00:26:57 +00:00
Rafael Espindola 801b42de31 ARM: move some logic from processFixupValue to applyFixup.
processFixupValue is called on every relaxation iteration. applyFixup
is only called once at the very end. applyFixup is then the correct
place to do last minute changes and value checks.

While here, do proper range checks again for fixup_arm_thumb_bl. We
used to do it, but dropped because of thumb2. We now do it again, but
use the thumb2 range.

llvm-svn: 306177
2017-06-23 22:52:36 +00:00
Rafael Espindola 8a261c2565 Add a common error checking for some invalid expressions.
This refactors a bit of duplicated code and fixes an assertion failure
on ELF.

llvm-svn: 306035
2017-06-22 17:25:35 +00:00
Rafael Espindola 88d9e37ec8 Use a MutableArrayRef. NFC.
llvm-svn: 305968
2017-06-21 23:06:53 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Alex Bradbury 866113c2ea Add MCContext argument to MCAsmBackend::applyFixup for error reporting
A number of backends (AArch64, MIPS, ARM) have been using
MCContext::reportError to report issues such as out-of-range fixup values in
their TgtAsmBackend. This is great, but because MCContext couldn't easily be
threaded through to the adjustFixupValue helper function from its usual
callsite (applyFixup), these backends ended up adding an MCContext* argument
and adding another call to applyFixup to processFixupValue. Adding an
MCContext parameter to applyFixup makes this unnecessary, and even better -
applyFixup can take a reference to MCContext rather than a potentially null
pointer.

Differential Revision: https://reviews.llvm.org/D30264

llvm-svn: 299529
2017-04-05 10:16:14 +00:00
Eugene Zelenko 1d43552a40 [MC] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 294369
2017-02-07 23:02:00 +00:00
Peter Collingbourne d763c4cc85 MC: Introduce the ABS8 symbol modifier.
@ABS8 can be applied to symbols which appear as immediate operands to
instructions that have a 8-bit immediate form for that operand. It causes
the assembler to use the 8-bit form and an 8-bit relocation (e.g. R_386_8
or R_X86_64_8) for the symbol.

Differential Revision: https://reviews.llvm.org/D28688

llvm-svn: 293667
2017-01-31 18:28:44 +00:00
Evgeniy Stepanov f2d9a46b5f Fix aliases to thumbfunc-based exprs to be thumbfunc.
If F is a Thumb function symbol, and G = F + const, and G is a
function symbol, then G is Thumb. Because what else could it be?

Differential Revision: https://reviews.llvm.org/D28878

llvm-svn: 292514
2017-01-19 20:04:11 +00:00
Oliver Stannard 268f42f1ce [Assembler] Better error messages for .org directive
Currently, the error messages we emit for the .org directive when the
expression is not absolute or is out of range do not include the line
number of the directive, so it can be hard to track down the problem if
a file contains many .org directives.

This patch stores the source location in the MCOrgFragment, so that it
can be used for diagnostics emitted during layout.

Since layout is an iterative process, and the errors are detected during
each iteration, it would have been possible for errors to be reported
multiple times. To prevent this, I've made the assembler bail out after
each iteration if any errors have been reported. This will still allow
multiple unrelated errors to be reported in the common case where they
are all detected in the first round of layout.

Differential Revision: https://reviews.llvm.org/D27411

llvm-svn: 289643
2016-12-14 10:43:58 +00:00
Davide Italiano f17d48e58a [MC] Don't crash when trying to emit a relocation against .bss.
Turn that into an error instead.

llvm-svn: 276783
2016-07-26 18:16:33 +00:00
Nirav Dave 8603062ee4 Fix branch relaxation in 16-bit mode.
Thread through MCSubtargetInfo to relaxInstruction function allowing relaxation
to generate jumps with 16-bit sized immediates in 16-bit mode.

This fixes PR22097.

Reviewers: dwmw2, tstellarAMD, craig.topper, jyknight

Subscribers: jfb, arsenm, jyknight, llvm-commits, dsanders

Differential Revision: http://reviews.llvm.org/D20830

llvm-svn: 275068
2016-07-11 14:23:53 +00:00
Eric Christopher f0ea2207a4 There's no reason to use _ to name variables different just for construction.
llvm-svn: 270622
2016-05-24 22:15:54 +00:00
Colin LeMahieu 485d905510 [MCAssembler] Allow backend to finalize layout post-relaxation.
Differential revision: http://reviews.llvm.org/D19429

llvm-svn: 267796
2016-04-27 21:26:13 +00:00
David Majnemer 408b5e6603 [MC] Add support for encoding CodeView variable definition ranges
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
2016-02-05 01:55:49 +00:00
Reid Kleckner 1fcd610c94 [codeview] Wire up the .cv_inline_linetable directive
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
2016-02-02 17:41:18 +00:00
Rafael Espindola a39d305ded Use larger write sizes for MCFillFragment.
This brings the pr26208 testcase down to 3.2 seconds. Not checking it in
since it does create a 4GB .o file.

llvm-svn: 258149
2016-01-19 17:47:48 +00:00
Rafael Espindola 1a7e8b4bc1 Simplify MCFillFragment.
The value size was always 1 or 0, so we don't need to store it.

In a no asserts build this takes the testcase of pr26208 from 11 to 10
seconds.

llvm-svn: 258141
2016-01-19 16:57:08 +00:00
Chandler Carruth 8d736236d3 [ptr-traits] Split the MCFragment type hierarchy out of the MCAssembler
header to its own header, allowing users of fragments to have a narrower
header file, and avoid circular header dependencies when getting the
definition of MCSection prior to inspecting traits on MCSection
pointers.

This is part of a series of patches to allow LLVM to check for complete
pointee types when computing its pointer traits. This is absolutely
necessary to get correct (or reproducible) results for things like how
many low bits are guaranteed to be zero.

Note that this doesn't in any way change the design of MC, it is just
moving code around to allow the *header files* to be more fine grained.
Without this, it is impossible to get a complete type for MCSection
where it is needed.

If anyone would prefer a different slicing of the header files, I'm
happy to oblige of course. =]

llvm-svn: 256548
2015-12-29 09:06:16 +00:00
David Majnemer 03e2cc3007 [MC, COFF] Support link /incremental conditionally
Today, we always take into account the possibility that object files
produced by MC may be consumed by an incremental linker.  This results
in us initialing fields which vary with time (TimeDateStamp) which harms
hermetic builds (e.g. verifying a self-host went well) and produces
sub-optimal code because we cannot assume anything about the relative
position of functions within a section (call sites can get redirected
through incremental linker thunks).

Let's provide an MCTargetOption which controls this behavior so that we
can disable this functionality if we know a-priori that the build will
not rely on /incremental.

llvm-svn: 256203
2015-12-21 22:09:27 +00:00
Oliver Stannard 9be59af3ab [Assembler] Make fatal assembler errors non-fatal
Currently, if the assembler encounters an error after parsing (such as an
out-of-range fixup), it reports this as a fatal error, and so stops after the
first error. However, for most of these there is an obvious way to recover
after emitting the error, such as emitting the fixup with a value of zero. This
means that we can report on all of the errors in a file, not just the first
one. MCContext::reportError records the fact that an error was encountered, so
we won't actually emit an object file with the incorrect contents.

Differential Revision: http://reviews.llvm.org/D14717

llvm-svn: 253328
2015-11-17 10:00:43 +00:00
Rafael Espindola 04d39260d6 Simplify .org processing and make it a bit more powerful.
We now always create the fragment, which lets us handle things like .org after
a .align.

llvm-svn: 252101
2015-11-04 23:50:29 +00:00