Commit Graph

268 Commits

Author SHA1 Message Date
Sam Clegg 12fd3da9d1 [WebAssembly] MC: Fix crash when -g specified.
At this point we don't output any debug sections or thier
relocations.

Differential Revision: https://reviews.llvm.org/D39076

llvm-svn: 316240
2017-10-20 21:28:38 +00:00
Sam Clegg 2176a9f2a3 [WebAssembly] Remove flags from MCSectionWasm
Looks like these were copied from the ELF sections but
don't apply to Wasm and were not used anywhere.

Also remove unused Wasm methods in MCContext.

Differential Revision: https://reviews.llvm.org/D37633

llvm-svn: 313058
2017-09-12 18:31:24 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +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
Evgeniy Stepanov 43dcf4d330 Fix asm printing of associated sections.
Make MCSectionELF::AssociatedSection be a link to a symbol, because
that's how it works in the assembly, and use it in the asm printer.

llvm-svn: 297769
2017-03-14 19:28:51 +00:00
Evgeniy Stepanov 00400d36c9 Disallow redefinition of section symbols.
Differential Revision: https://reviews.llvm.org/D30235

llvm-svn: 296180
2017-02-24 21:44:58 +00:00
Evgeniy Stepanov 0338ce83cd Initialize MCContext::InlineSrcMgr in the constructor.
Found with ASan (and a local source change) on test/CodeGen/XCore/section-name.ll.

llvm-svn: 296179
2017-02-24 21:44:52 +00:00
Dan Gohman 18eafb6c68 [WebAssembly] Add skeleton MC support for the Wasm container format
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.

Differential Revision: https://reviews.llvm.org/D26722

llvm-svn: 295803
2017-02-22 01:23:18 +00:00
Eugene Zelenko d96089b248 [MC] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
Same changes in files affected by reduced MC headers dependencies.

llvm-svn: 295009
2017-02-14 00:33:36 +00:00
Rafael Espindola dc1c3011fd Make it possible to set SHF_LINK_ORDER explicitly.
This will make it possible to add support for gcing user metadata
(asan for example).

llvm-svn: 294589
2017-02-09 14:59:20 +00:00
Sanne Wouda 2933875cc2 [Assembler] Enable nicer diagnostics for inline assembly.
Fixed test.

Summary:
Enables source location in diagnostic messages from the backend.  This
is after parsing, during finalization.  This requires the SourceMgr, the
inline assembly string buffer, and DiagInfo to still be alive after
EmitInlineAsm returns.

This patch creates a single SourceMgr for inline assembly inside the
AsmPrinter.  MCContext gets a pointer to this SourceMgr.  Using one
SourceMgr per call to EmitInlineAsm would make it difficult for
MCContext to figure out in which SourceMgr the SMLoc is located, while a
single SourceMgr can figure it out if it has multiple buffers.

The Str argument to EmitInlineAsm is copied into a buffer and owned by
the inline asm SourceMgr.  This ensures that DiagHandlers won't print
garbage.  (Clang emits a "note: instantiated into assembly here", which
refers to this string.)

The AsmParser gets destroyed before finalization, which means that the
DiagHandlers the AsmParser installs into the SourceMgr will be stale.
Restore the saved DiagHandlers.

Since now we're using just one SourceMgr for multiple inline asm
strings, we need to tell the AsmParser which buffer it needs to parse
currently.  Hand a buffer id -- returned from SourceMgr::
AddNewSourceBuffer -- to the AsmParser.

Reviewers: rnk, grosbach, compnerd, rengolin, rovka, anemet

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29441
    

llvm-svn: 294458
2017-02-08 14:48:05 +00:00
Diana Picus 79add417b4 Revert "[Assembler] Enable nicer diagnostics for inline assembly."
This reverts commit r294433 because it seems it broke the buildbots.

llvm-svn: 294448
2017-02-08 14:02:16 +00:00
Sanne Wouda 09adc245ea [Assembler] Enable nicer diagnostics for inline assembly.
Summary:
Enables source location in diagnostic messages from the backend.  This
is after parsing, during finalization.  This requires the SourceMgr, the
inline assembly string buffer, and DiagInfo to still be alive after
EmitInlineAsm returns.

This patch creates a single SourceMgr for inline assembly inside the
AsmPrinter.  MCContext gets a pointer to this SourceMgr.  Using one
SourceMgr per call to EmitInlineAsm would make it difficult for
MCContext to figure out in which SourceMgr the SMLoc is located, while a
single SourceMgr can figure it out if it has multiple buffers.

The Str argument to EmitInlineAsm is copied into a buffer and owned by
the inline asm SourceMgr.  This ensures that DiagHandlers won't print
garbage.  (Clang emits a "note: instantiated into assembly here", which
refers to this string.)

The AsmParser gets destroyed before finalization, which means that the
DiagHandlers the AsmParser installs into the SourceMgr will be stale.
Restore the saved DiagHandlers.

Since now we're using just one SourceMgr for multiple inline asm
strings, we need to tell the AsmParser which buffer it needs to parse
currently.  Hand a buffer id -- returned from SourceMgr::
AddNewSourceBuffer -- to the AsmParser.

Reviewers: rnk, grosbach, compnerd, rengolin, rovka, anemet

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29441

llvm-svn: 294433
2017-02-08 10:20:07 +00:00
Rafael Espindola 13a79bbfe5 Change how we handle section symbols on ELF.
On ELF every section can have a corresponding section symbol. When in
an assembly file we have

.quad .text

the '.text' refers to that symbol.

The way we used to handle them is to leave .text an undefined symbol
until the very end when the object writer would map them to the
actual section symbol.

The problem with that is that anything before the end would see an
undefined symbol. This could result in bad diagnostics
(test/MC/AArch64/label-arithmetic-diags-elf.s), or incorrect results
when using the asm streamer (est/MC/Mips/expansion-jal-sym-pic.s).

Fixing this will also allow using the section symbol earlier for
setting sh_link of SHF_METADATA sections.

This patch includes a few hacks to avoid changing our behaviour when
handling conflicts between section symbols and other symbols. I
reported pr31850 to track that.

llvm-svn: 293936
2017-02-02 21:26:06 +00:00
Prakhar Bahuguna 52a7dd7d78 [ARM] Implement execute-only support in CodeGen
This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The following changes are involved:

* Add the CodeGen option "-arm-execute-only" to the ARM code generator.
* Add the clang flag "-mexecute-only" as well as the GCC-compatible
  alias "-mpure-code" to enable this option.
* When enabled, literal pools are replaced with MOVW/MOVT instructions,
  with VMOV used in addition for floating-point literals. As the MOVT
  instruction is required, execute-only support is only available in
  Thumb mode for targets supporting ARMv8-M baseline or Thumb2.
* Jump tables are placed in data sections when in execute-only mode.
* The execute-only text section is assigned section ID 0, and is
  marked as unreadable with the SHF_ARM_PURECODE flag with symbol 'y'.
  This also overrides selection of ELF sections for globals.

llvm-svn: 289784
2016-12-15 07:59:08 +00:00
Mandeep Singh Grang 9a561aa34c [llvm] Fix D26214: Move error handling out of MC and to the callers.
Summary: Related clang patch; https://reviews.llvm.org/D27360

Reviewers: t.p.northover, grosbach, compnerd, echristo

Subscribers: compnerd, mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D27359

llvm-svn: 288763
2016-12-06 02:49:17 +00:00
Dan Gohman abceeeee5d [MC] Generalize MCContext's SectionSymbols field.
Change SectionSymbols so that it doesn't hard-code ELF types, so that
it can be used for non-ELF targets.

llvm-svn: 288607
2016-12-03 23:55:57 +00:00
Mandeep Singh Grang 32360071a0 [llvm] Implement support for -defsym assembler option
Summary:
Changes to llvm-mc to move common logic to separate function.

Related clang patch: https://reviews.llvm.org/D26213

Reviewers: rafael, t.p.northover, colinl, echristo, rengolin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D26214

llvm-svn: 288396
2016-12-01 18:42:04 +00:00
Eric Christopher 8e94895555 Tidy spelling and grammar.
llvm-svn: 282672
2016-09-29 02:03:44 +00:00
Reid Kleckner a5b1eef846 [MC] Move .cv_loc management logic out of MCContext
MCContext already has many tasks, and separating CodeView out from it is
probably a good idea. The .cv_loc tracking was modelled on the DWARF
tracking which lived directly in MCContext.

Removes the inclusion of MCCodeView.h from MCContext.h, so now there are
only 10 build actions while I hack on CodeView support instead of 265.

llvm-svn: 279847
2016-08-26 17:58:37 +00:00
Eric Christopher 36e601c6dc Add support for allowing us to create uniquely identified "COMDAT" or "ELF
Group" sections while lowering. In particular, for ELF sections this is
useful for creating function-specific groups that get merged into the
same named section.

Also use const Twine& instead of StringRef for the getELF functions
while we're here.

Differential Revision: http://reviews.llvm.org/D21743

llvm-svn: 274336
2016-07-01 06:07:38 +00:00
Igor Laevsky 7b998853ee [MCContext] Don't use getenv inside class constructor
Differential Revision: http://reviews.llvm.org/D21471

llvm-svn: 273005
2016-06-17 15:19:41 +00:00
Richard Smith b910e56604 Revert r270569 (teach llvm-mc to generate compressed debug sections in zlib
style). It appears that current ELF linkers are not ready for this.

llvm-svn: 270638
2016-05-25 00:14:12 +00:00
George Rimar 68003e0fbf Recommit r270070 ([llvm-mc] - Teach llvm-mc to generate compressed debug sections in zlib style.)
Now, after landing r270560, r270557, r270320 it is a proper time.

Original commit message:
[llvm-mc] - Teach llvm-mc to generate compressed debug sections in zlib style.

Before this patch llvm-mc generated zlib-gnu styled sections. 
That means no SHF_COMPRESSED flag was set, magic 'zlib' signature
was used in combination with full size field. Sections were renamed to "*.z*".
This patch reimplements the compression style to zlib one as zlib-gnu looks
to be depricated everywhere.

Differential revision: http://reviews.llvm.org/D20331

llvm-svn: 270569
2016-05-24 15:19:35 +00:00
George Rimar cf2bf9d015 Temporarily revert r270070
It broke buildbot:
http://lab.llvm.org:8011/builders/clang-s390x-linux/builds/4817/steps/ninja%20check%201/logs/stdio

Actually it is just because D20273 not yet commited, but these 2 were crossing with each other,
and I`ll better find the way to land them separatelly soon.

Initial commit message:

[llvm-mc] - Teach llvm-mc to generate compressed debug sections in zlib style.

Before this patch llvm-mc generated zlib-gnu styled sections. 
That means no SHF_COMPRESSED flag was set, magic 'zlib' signature
was used in combination with full size field. Sections were renamed to "*.z*".
This patch reimplements the compression style to zlib one as zlib-gnu looks
to be depricated everywhere.

Differential revision: http://reviews.llvm.org/D20331

llvm-svn: 270075
2016-05-19 15:58:05 +00:00
George Rimar 99c901fc47 [llvm-mc] - Teach llvm-mc to generate compressed debug sections in zlib style.
Before this patch llvm-mc generated zlib-gnu styled sections. 
That means no SHF_COMPRESSED flag was set, magic 'zlib' signature
was used in combination with full size field. Sections were renamed to "*.z*".
This patch reimplements the compression style to zlib one as zlib-gnu looks
to be depricated everywhere.

Differential revision: http://reviews.llvm.org/D20331

llvm-svn: 270070
2016-05-19 15:08:31 +00:00
Reid Kleckner 97837b7b09 [MC] Create unique .pdata sections for every .text section
Summary:
This adds a unique ID to the COFF section uniquing map, similar to the
one we have for ELF.  The unique id is not currently exposed via the
assembler because we don't have a use case for it yet. Users generally
create .pdata with the .seh_* family of directives, and the assembler
internally needs to produce .pdata and .xdata sections corresponding to
the code section.

The association between .text sections and the assembler-created .xdata
and .pdata sections is maintained as an ID field of MCSectionCOFF. The
CFI-related sections are created with the given unique ID, so if more
code is added to the same text section, we can find and reuse the CFI
sections that were already created.

Reviewers: majnemer, rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D19376

llvm-svn: 268331
2016-05-02 23:22:18 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
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
2016-04-18 09:17:29 +00:00
Evgeniy Stepanov a023f79db1 Handle section vs global name conflict.
This is a fix for PR26941.

When there is both a section and a global definition with the same
name, the global wins.

Section symbols are not added to the symbol table; section references
are left undefined and fixed up in the object writer unless they've
been satisfied by some other definition.

llvm-svn: 264649
2016-03-28 20:36:28 +00:00
Justin Bogner 8809c40270 MC: Don't access the filesystem in MCContext's constructor
MCContext shouldn't be accessing the filesystem - that's a gross
layering violation and makes it awkward to use as a library or in a
daemon where it may not even be allowed filesystem access.

The CWD lookup here is normally redundant anyway, since the calling
context either also looks up the CWD or sets this to something more
specific. Here, we fix up the one caller that doesn't already set up a
debug compilation dir and make it clear that the responsibility for
such set up is in the users of MCContext.

llvm-svn: 264109
2016-03-22 22:24:29 +00:00
Reid Kleckner 2214ed8937 Reland "[CodeView] Use assembler directives for line tables"
This reverts commit r259126 and relands r259117.

This time with updated library dependencies.

llvm-svn: 259130
2016-01-29 00:49:42 +00:00
Reid Kleckner 00d9639c24 Revert "[CodeView] Use assembler directives for line tables"
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
2016-01-29 00:13:28 +00:00
Reid Kleckner c62e379d22 [CodeView] Use assembler directives for line tables
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
2016-01-28 23:31:52 +00:00
Rafael Espindola c49ac5e7c2 Use std::unique_ptr. NFC.
llvm-svn: 255852
2015-12-16 23:49:14 +00:00
Oliver Stannard 07b43d39a8 [Assembler] Allow non-fatal errors after parsing
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
2015-11-17 09:58:07 +00:00
Akira Hatanaka b11ef0897c Reduce the size of MCRelaxableFragment.
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
2015-11-14 06:35:56 +00:00
Keno Fischer 21a7f23666 Clear SectionSymbols in MCContext::Reset
This was just forgotten when SectionSymbols was introduced and could cause
corruption if the MCContext was reused after Reset.

Reviewers: rafael

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13547

llvm-svn: 249854
2015-10-09 17:24:54 +00:00
Rafael Espindola 4264e2d531 Use SpecificBumpPtrAllocator to simplify the MCSeciton destruction.
llvm-svn: 249589
2015-10-07 19:08:19 +00:00
Reid Kleckner 1f13d4789f Sink COFF.h MC include into .cpp files
This prevents MC clients from getting COFF.h, which conflicts with
winnt.h macros. Also a minor IWYU cleanup. Now the only public headers
including COFF.h are in Object, and they actually need it.

llvm-svn: 246784
2015-09-03 16:41:50 +00:00
Rafael Espindola dbaf0498a9 Revert "Centralize the information about which object format we are using."
This reverts commit r245047.

It was failing on the darwin bots. The problem was that when running

./bin/llc -march=msp430

llc gets to

  if (TheTriple.getTriple().empty())
    TheTriple.setTriple(sys::getDefaultTargetTriple());

Which means that we go with an arch of msp430 but a triple of
x86_64-apple-darwin14.4.0 which fails badly.

That code has to be updated to select a triple based on the value of
march, but that is not a trivial fix.

llvm-svn: 245062
2015-08-14 15:48:41 +00:00
Rafael Espindola 90eb70c8a7 Centralize the information about which object format we are using.
Other than some places that were handling unknown as ELF, this should
have no change. The test updates are because we were detecting
arm-coff or x86_64-win64-coff as ELF targets before.

It is not clear if the enum should live on the Triple. At least now it lives
in a single location and should be easier to move somewhere else.

llvm-svn: 245047
2015-08-14 13:31:17 +00:00
Daniel Jasper 41de8027b1 Revert r240302 ("Bring r240130 back.").
This causes errors like:

  ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
  may overflow at runtime; recompile with -fPIC
  blah.cc:function f(): error: undefined reference to ''
  blah.o:g(): error: undefined reference to ''

I have not yet come up with an appropriate reproduction.

llvm-svn: 240394
2015-06-23 11:31:32 +00:00
Rafael Espindola 2d6bae2e09 Bring r240130 back.
Now that pr23900 is fixed, we can bring it back with no changes.

Original message:

Make all temporary symbols unnamed.

What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

llvm-svn: 240302
2015-06-22 17:52:52 +00:00
Nico Weber 67e715ff7d Revert 240130, it caused crashes (repro in PR23900).
llvm-svn: 240193
2015-06-19 23:43:47 +00:00
Rafael Espindola 284a750c5f Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

llvm-svn: 240130
2015-06-19 12:16:55 +00:00
Rafael Espindola f27fa2bb9d Use named temporaries for directional labels.
Directional labels can show up in symbol tables (and we have a llvm-mc test for
that). Given that, we need to make sure they are named.

With that out of the way, use setUseNamesOnTempLabels in llvm-mc so that it
too benefits from the memory saving.

llvm-svn: 239914
2015-06-17 16:26:47 +00:00
Pete Cooper 234b875690 Allocate space for MCSymbol::Name only if required.
Similarly to User which allocates a number of Use's prior to the this pointer,
allocate space for the Name* for MCSymbol only when we need a name.

Given that an MCSymbol is 48-bytes on 64-bit systems, this saves a decent % of space.

Given the verify_uselistorder test case with debug info and llc, 50k symbols have names
out of 700k so this optimises for the common case of temporary unnamed symbols.

Reviewed by David Blaikie.

llvm-svn: 239423
2015-06-09 18:36:13 +00:00
Pete Cooper eb012fa761 Add MCSymbolMachO which will be used to hide the MCSymbolMachO flags.
Reviewed by Rafael Espíndola.

llvm-svn: 239315
2015-06-08 17:17:23 +00:00
Pete Cooper ad9f9c3517 Add MCSymbolCOFF class and use it to get and set the COFF type field.
Reviewed by Rafael Espíndola.

llvm-svn: 239312
2015-06-08 17:17:12 +00:00
Pete Cooper a3ab3841c0 Change MCSymbol IsELF to an enum to support future MCSymbolCOFF and MCSymbolMachO.
Reviewed by Rafael Espíndola.

llvm-svn: 239311
2015-06-08 17:17:09 +00:00
Rafael Espindola 3e9e72a56b Clarify when we can avoid creating names for temp symbols.
Some temporary symbols are created by MC itself. These symbols are never used
for lookup and are never included in the object symbol table, so we can
avoid creating a name for them.

Other temporaries are created by CodeGen or by the user by explicitly asking
for a name starting with .L (or L on MachO).

These temporaries behave like regular symbols, we just try to avoid including
them in the object symbol table, but sometimes they end up there:

const char *foo() {
  return "abc" + 3;
}

will have a relocation pointing to a .L symbol.

It just so happens that almost all MC created temporary has the AlwaysAddSuffix
option and CodeGen/user created ones don't.

One interesting future optimization would be to use unnamed symbols for
all temporaries, but that would require use an st_name of 0 or
having the object writer create the names if a symbol does end up in the
symbol table.

No testcase since this just avoid creating a few extra names for MC created
temporaries.

llvm-svn: 238887
2015-06-02 22:52:13 +00:00
Rafael Espindola 0ccf9b71f3 Pass a MCSymbolELF to a few ELF only functions. NFC.
llvm-svn: 238868
2015-06-02 21:30:13 +00:00
Rafael Espindola a869576008 Create a MCSymbolELF.
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.

This reduces the size of MCSymbol from 56 to 48 bytes.

llvm-svn: 238801
2015-06-02 00:25:12 +00:00
Benjamin Kramer 412c4dbbd9 [MC] Simplify code. No functionality change intended.
llvm-svn: 238676
2015-05-31 18:49:28 +00:00
Rafael Espindola ed34d58c09 Move MCSection destruction to MCContext::reset.
Fixes the leaks when running llc.

Also found by an asan bot.

llvm-svn: 238167
2015-05-26 01:52:19 +00:00
Rafael Espindola 24d285d31b Call the destructors of the MCSections.
They now contain the fragments. If we don't call the destructors the
fragments leak.

Found by an asan bot.

llvm-svn: 238161
2015-05-26 00:32:28 +00:00
Duncan P. N. Exon Smith 03656162a3 MC: Shave a pointer off of MCSymbol::Name
Shave a pointer off of `MCSymbolName` by storing `StringMapEntry<bool>*`
instead of `StringRef`.  This brings `sizeof(MCSymbol)` down to 64 on
64-bit platforms, a nice round number.  My profile showed memory
dropping from 914 MB down to 908 MB, roughly 0.7%.  Other than memory
usage, no functionality change here.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238005
2015-05-22 06:04:42 +00:00
Rafael Espindola 0709a7bd1a Move alignment from MCSectionData to MCSection.
This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936
2015-05-21 19:20:38 +00:00
Rafael Espindola e2fdf8d60e Avoid unnecessary section switching. NFC.
llvm-svn: 237913
2015-05-21 17:00:40 +00:00
Rafael Espindola e07467901b Remove yet another method of creating begin and end symbol for sections.
I missed this one when first unifying how we handle begin and end symbols.

llvm-svn: 237912
2015-05-21 16:52:32 +00:00
Reid Kleckner 2632f0df48 [WinEH] Store pointers to the LSDA in the exception registration object
We aren't yet emitting the LSDA yet, so this will still fail to
assemble.

llvm-svn: 237852
2015-05-20 23:08:04 +00:00
Jim Grosbach 008359ae4a MC: clang-format MCContext. NFC.
llvm-svn: 237595
2015-05-18 18:43:23 +00:00
Jim Grosbach 6f482000e9 MC: Clean up method names in MCContext.
The naming was a mish-mash of old and new style. Update to be consistent
with the new. NFC.

llvm-svn: 237594
2015-05-18 18:43:14 +00:00
Duncan P. N. Exon Smith c177fec93f MC: Skip names of temporary symbols in object streamer
Don't create names for temporary symbols when using an object streamer.
The names never make it to the output anyway.  From the starting point
of r236629, my heap profile says this drops peak memory usage from 1100
MB to 1058 MB for CodeGen of `verify-uselistorder`, a savings of almost
4% on peak memory, and removes `StringMap<bool, BumpPtrAllocator...>`
from the profile entirely.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 236642
2015-05-06 21:34:34 +00:00
Rafael Espindola 55a3afb418 Remove the GroupMapTy DenseMap. NFC.
Instead use the Group symbol of MCSectionELF.

llvm-svn: 236033
2015-04-28 21:07:28 +00:00
Matt Arsenault 9897e03b11 Revert accidentally committed "MC: Allow targets to stop symbol name quoting"
llvm-svn: 235672
2015-04-23 23:34:51 +00:00
Matt Arsenault 0bad85de10 MC: Allow targets to stop symbol name quoting
Currently symbol names are printed in quotes if it contains something
outside of the arbitrary set of characters that isAcceptableChar tests
for. On somem targets, it is never OK to print a symbol name in quotes
so allow targets to opt out of this behavior.

llvm-svn: 235670
2015-04-23 23:34:05 +00:00
Rafael Espindola 61e8ce36be Store the sh_link of ARM_EXIDX directly in MCSectionELF.
This avoids some pretty horrible and broken name based section handling.

llvm-svn: 234142
2015-04-06 04:25:18 +00:00
Rafael Espindola b73b70ebff Simplify mapping from relocation sections to relocated sections.
Just store the section in MCSectionELF. This avoids multiple hash lookups.

This will also be used by ARM_EXIDX.

llvm-svn: 234139
2015-04-06 03:09:30 +00:00
Rafael Espindola 972d55851a Don't mix overload and default values.
It makes it hard to see which one is being called.

llvm-svn: 234100
2015-04-04 18:16:01 +00:00
Rafael Espindola 8ca44f0b5c Implement unique sections with an unique ID.
This allows the compiler/assembly programmer to switch back to a
section. This in turn fixes the bootstrap failure on powerpc (tested
on gcc110) without changing the ppc codegen at all.

I will try to cleanup the various getELFSection overloads in a  followup patch.
Just using a default argument now would lead to ambiguities.

llvm-svn: 234099
2015-04-04 18:02:01 +00:00
David Majnemer a225a19dd0 [WinEH] Generate .xdata for catch handlers
This lets us catch exceptions in simple cases.

N.B. Things that do not work include (but are not limited to):
- Throwing from within a catch handler.
- Catching an object with a named catch parameter.
- 'CatchHigh' is fictitious, we aren't sure of its purpose.
- We aren't entirely efficient with regards to the number of EH states
  that we generate.
- IP-to-State tables are sensitive to the order of emission.

llvm-svn: 233767
2015-03-31 22:35:44 +00:00
Rafael Espindola d3ac79b3b4 Save a std::string.
The group names are always symbol names, so we can use a StringRef.

llvm-svn: 233545
2015-03-30 13:59:06 +00:00
Rafael Espindola c9d069222e Special case the creation of relocation sections.
These sections are never looked up and we know when have to create them. Use
that to save adding them to the regular map and avoid a symbol->string->symbol
conversion for the group symbol.

This also makes the implementation independent of the details of how unique
sections are implemented.

llvm-svn: 233539
2015-03-30 13:39:16 +00:00
Rafael Espindola 44d5057e38 Add two small structs for readability in place of std::pair and std::tuple. NFC.
llvm-svn: 233422
2015-03-27 21:34:24 +00:00
Rafael Espindola 9ab09237dc Centralize the handling of unique ids for temporary labels.
Before this patch code wanting to create temporary labels for a given entity
(function, cu, exception range, etc) had to keep its own counter to have stable
symbol names.

createTempSymbol would still add a suffix to make sure a new symbol was always
returned, but it kept a single counter. Because of that, if we were to use
just createTempSymbol("cu_begin"), the label could change from cu_begin42 to
cu_begin43 because some other code started using temporary labels.

Simplify this by just keeping one counter per prefix and removing the various
specialized counters.

llvm-svn: 232535
2015-03-17 20:07:06 +00:00
Yaron Keren d7c546c935 Remove LookupSymbol(StringRef) and optimize LookupSymbol(Twine).
Same as MakeArgString in r232465, keep only LookupSymbol(Twine)
while making sure it handles the StringRef like cases efficiently
using twine::toStringRef.

llvm-svn: 232517
2015-03-17 18:55:30 +00:00
Yaron Keren 1ee89fc432 Teach Twine to support SmallString.
Enable removing .str() member calls for these frequent cases. 

 http://reviews.llvm.org/D6372

llvm-svn: 232465
2015-03-17 09:51:17 +00:00
Rafael Espindola 6b9998b3eb Create symbols marking the start of a section earlier.
This lets us pass the symbol to the constructor and avoid the mutable field.

This also opens the way for outputting the symbol only when needed, instead
of outputting them at the start of the file.

llvm-svn: 231859
2015-03-10 22:00:25 +00:00
Rafael Espindola 6ed58a2d91 clang-format code that is about to change.
llvm-svn: 231848
2015-03-10 21:16:18 +00:00
Reid Kleckner cfb9ce53c1 Replace llvm.frameallocate with llvm.frameescape
Turns out it's pretty straightforward and simplifies the implementation.

Reviewers: andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D8051

llvm-svn: 231386
2015-03-05 18:26:34 +00:00
Pete Cooper ef21bd444d Remove MCStreamer.h include from MCContext.h and explictly include it where necessary. NFC
llvm-svn: 231193
2015-03-04 01:24:11 +00:00
Rafael Espindola 629cdbae94 Centralize handling of the eh_begin and eh_end labels.
This removes a bit of duplicated code and more importantly, remembers the
labels so that they don't need to be looked up by name.

This in turn allows for any name to be used and avoids a crash if the name
we wanted was already taken.

llvm-svn: 230772
2015-02-27 18:18:39 +00:00
Rafael Espindola 68fa249cb5 Add r228980 back.
Add support for having multiple sections with the same name and comdat.

Using this in combination with -ffunction-sections allows LLVM to output a .o
file with mulitple sections named .text. This saves space by avoiding long
unique names of the form .text.<C++ mangled name>.

llvm-svn: 229541
2015-02-17 20:48:01 +00:00
Chandler Carruth d99f427e31 Revert a series of commits starting at r228886 which is triggering some
regressions for LLDB on Linux. Rafael indicated on lldb-dev that we
should just go ahead and revert these but that he wasn't at a computer.
The patches backed out are as follows:

r228980: Add support for having multiple sections with the name and ...
r228889: Invert the section relocation map.
r228888: Use the existing SymbolTableIndex intsead of doing a lookup.
r228886: Create the Section -> Rel Section map when it is first needed.

These patches look pretty nice to me, so hoping its not too hard to get
them re-instated. =D

llvm-svn: 229080
2015-02-13 07:52:39 +00:00
Rafael Espindola b6a812ebb1 Add support for having multiple sections with the same name and comdat.
Using this in combination with -ffunction-sections allows LLVM to output a .o
file with mulitple sections named .text. This saves space by avoiding long
unique names of the form .text.<C++ mangled name>.

llvm-svn: 228980
2015-02-12 23:29:51 +00:00
Rafael Espindola ba31e27f0a Compute the ELF SectionKind from the flags.
Any code creating an MCSectionELF knows ELF and already provides the flags.

SectionKind is an abstraction used by common code that uses a plain
MCSection.

Use the flags to compute the SectionKind. This removes a lot of
guessing and boilerplate from the MCSectionELF construction.

llvm-svn: 227476
2015-01-29 17:33:21 +00:00
Reid Kleckner e9b8931873 Add the llvm.frameallocate and llvm.recoverframeallocation intrinsics
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.

Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.

These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.

Reviewers: echristo, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D6493

llvm-svn: 225746
2015-01-13 00:48:10 +00:00
David Blaikie 5106ce7897 Remove StringMap::GetOrCreateValue in favor of StringMap::insert
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)

Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.

llvm-svn: 222319
2014-11-19 05:49:42 +00:00
Rafael Espindola b66130209b Add back commits r219835 and a fixed version of r219829.
The only difference from r219829 is using

getOrCreateSectionSymbol(*ELFSec)

instead of

GetOrCreateSymbol(ELFSec->getSectionName())

in ELFObjectWriter which causes us to use the correct section symbol even if
we have multiple sections with the same name.

Original messages:

r219829:
Correctly handle references to section symbols.

When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

r219835:
Allow forward references to section symbols.

llvm-svn: 220021
2014-10-17 01:48:58 +00:00
Rafael Espindola 4544a4062c Revert commit r219835 and r219829.
Revert "Correctly handle references to section symbols."
Revert "Allow forward references to section symbols."

Rui found a regression I am debugging.

llvm-svn: 220010
2014-10-17 01:06:02 +00:00
Rafael Espindola 78206c3576 Allow forward references to section symbols.
llvm-svn: 219835
2014-10-15 19:30:18 +00:00
Rafael Espindola a74b5e6823 Correctly handle references to section symbols.
When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

llvm-svn: 219829
2014-10-15 18:55:30 +00:00
Yaron Keren 559b47d051 Add and update reset() and doInitialization() methods to MC* and passes.
This enables reusing a PassManager instead of re-constructing it every time.

llvm-svn: 217948
2014-09-17 09:25:36 +00:00
Reid Kleckner 7c4059eb89 MC Win64: Put unwind info for COMDAT code into the same COMDAT group
Summary:
This fixes a long standing issue where we would emit many little .text
sections and only one .pdata and .xdata section. Now we generate one
.pdata / .xdata pair per .text section and associate them correctly.

Fixes PR19667.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5181

llvm-svn: 217176
2014-09-04 17:42:03 +00:00
David Majnemer 8bce66b093 CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF
COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section.  This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.

This fixes PR20262.

Differential Revision: http://reviews.llvm.org/D4482

llvm-svn: 213006
2014-07-14 22:57:27 +00:00
Alp Toker a55b95b58a SourceMgr: make valid buffer IDs start from one
Use 0 for the invalid buffer instead of -1/~0 and switch to unsigned
representation to enable more idiomatic usage.

Also introduce a trivial SourceMgr::getMainFileID() instead of hard-coding 0/1
to identify the main file.

llvm-svn: 212398
2014-07-06 10:33:31 +00:00
David Majnemer c57d038240 MC: Fix associative sections on COFF
COFF sections in MC were represented by a tuple of section-name and
COMDAT-name.  This is not sufficient to represent a .text section
associated with another .text section; we need a way to distinguish
between the key section and the one marked associative.

llvm-svn: 211913
2014-06-27 17:19:44 +00:00
Alp Toker e69170a110 Revert "Introduce a string_ostream string builder facilty"
Temporarily back out commits r211749, r211752 and r211754.

llvm-svn: 211814
2014-06-26 22:52:05 +00:00
Alp Toker 614717388c Introduce a string_ostream string builder facilty
string_ostream is a safe and efficient string builder that combines opaque
stack storage with a built-in ostream interface.

small_string_ostream<bytes> additionally permits an explicit stack storage size
other than the default 128 bytes to be provided. Beyond that, storage is
transferred to the heap.

This convenient class can be used in most places an
std::string+raw_string_ostream pair or SmallString<>+raw_svector_ostream pair
would previously have been used, in order to guarantee consistent access
without byte truncation.

The patch also converts much of LLVM to use the new facility. These changes
include several probable bug fixes for truncated output, a programming error
that's no longer possible with the new interface.

llvm-svn: 211749
2014-06-26 00:00:48 +00:00