93 Commits

Author SHA1 Message Date
George Rimar
1bfa43df58 Recommit r368812 "[llvm/Object] - Convert SectionRef::getName() to return Expected<>"
Changes: no changes. A fix for the clang code will be landed right on top.

Original commit message:

SectionRef::getName() returns std::error_code now.
Returning Expected<> instead has multiple benefits.

For example, it forces user to check the error returned.
Also Expected<> may keep a valuable string error message,
what is more useful than having a error code.
(Object\invalid.test was updated to show the new messages printed.)

This patch makes a change for all users to switch to Expected<> version.

Note: in a few places the error returned was ignored before my changes.
In such places I left them ignored. My intention was to convert the interface
used, and not to improve and/or the existent users in this patch.
(Though I think this is good idea for a follow-ups to revisit such places
and either remove consumeError calls or comment each of them to clarify why
it is OK to have them).

Differential revision: https://reviews.llvm.org/D66089

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368826 91177308-0d34-0410-b5e6-96231b3b80d8
2019-08-14 11:10:11 +00:00
George Rimar
899e01b67d Revert r368812 "[llvm/Object] - Convert SectionRef::getName() to return Expected<>"
It broke clang BB: http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/16455



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368813 91177308-0d34-0410-b5e6-96231b3b80d8
2019-08-14 08:56:55 +00:00
George Rimar
0d8949846a [llvm/Object] - Convert SectionRef::getName() to return Expected<>
SectionRef::getName() returns std::error_code now.
Returning Expected<> instead has multiple benefits.

For example, it forces user to check the error returned.
Also Expected<> may keep a valuable string error message,
what is more useful than having a error code.
(Object\invalid.test was updated to show the new messages printed.)

This patch makes a change for all users to switch to Expected<> version.

Note: in a few places the error returned was ignored before my changes.
In such places I left them ignored. My intention was to convert the interface
used, and not to improve and/or the existent users in this patch.
(Though I think this is good idea for a follow-ups to revisit such places
and either remove consumeError calls or comment each of them to clarify why
it is OK to have them).

Differential revision: https://reviews.llvm.org/D66089

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368812 91177308-0d34-0410-b5e6-96231b3b80d8
2019-08-14 08:46:54 +00:00
Sunil Srivastava
308323db52 Print reasonable representations of type names in llvm-nm, readelf and readobj
For type values that do not have proper names, print reasonable representation
in llvm-nm, llvm-readobj and llvm-readelf, matching GNU tools.s

Fixes PR41713.

Differential Revision: https://reviews.llvm.org/D65537



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368451 91177308-0d34-0410-b5e6-96231b3b80d8
2019-08-09 16:54:51 +00:00
Sjoerd Meijer
afefcdba98 [ARM] add target arch definitions for 8.1-M and MVE
This adds:
- LLVM subtarget features to make all the new instructions conditional on,
- CPU and FPU names for use on clang's command line, with default FPUs set
  so that "armv8.1-m.main+fp" and "armv8.1-m.main+fp.dp" will select the right
  FPU features,
- architecture extension names "mve" and "mve.fp",
- ABI build attribute support for v8.1-M (a new value for Tag_CPU_arch) and MVE
  (a new actual tag).

Patch mostly by Simon Tatham.

Differential Revision: https://reviews.llvm.org/D60698


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362090 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-30 12:57:04 +00:00
Simon Tatham
2edda5220d [ARM] Replace fp-only-sp and d16 with fp64 and d32.
Those two subtarget features were awkward because their semantics are
reversed: each one indicates the _lack_ of support for something in
the architecture, rather than the presence. As a consequence, you
don't get the behavior you want if you combine two sets of feature
bits.

Each SubtargetFeature for an FP architecture version now comes in four
versions, one for each combination of those options. So you can still
say (for example) '+vfp2' in a feature string and it will mean what
it's always meant, but there's a new string '+vfp2d16sp' meaning the
version without those extra options.

A lot of this change is just mechanically replacing positive checks
for the old features with negative checks for the new ones. But one
more interesting change is that I've rearranged getFPUFeatures() so
that the main FPU feature is appended to the output list *before*
rather than after the features derived from the Restriction field, so
that -fp64 and -d32 can override defaults added by the main feature.

Reviewers: dmgreen, samparker, SjoerdMeijer

Subscribers: srhines, javed.absar, eraman, kristof.beyls, hiraditya, zzheng, Petar.Avramovic, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D60691



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361845 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-28 16:13:20 +00:00
Fangrui Song
7287acf23f Recommit [Object] Change object::SectionRef::getContents() to return Expected<StringRef>
r360876 didn't fix 2 call sites in clang.

Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.

Follow-up of D61781.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360892 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-16 13:24:04 +00:00
Hans Wennborg
71eaa4f97d Revert r360876 "[Object] Change object::SectionRef::getContents() to return Expected<StringRef>"
It broke the Clang build, see llvm-commits thread.

> Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
>
> Follow-up of D61781.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360878 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-16 12:08:34 +00:00
Fangrui Song
a4d6bb66d0 [Object] Change object::SectionRef::getContents() to return Expected<StringRef>
Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.

Follow-up of D61781.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360876 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-16 11:33:48 +00:00
Fangrui Song
f2ac3eb20d [Object] Move ELF specific ObjectFile::getBuildAttributes to ELFObjectFileBase
Change the return type from std::error_code to Error and make the
function protected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360416 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-10 10:19:08 +00:00
Sunil Srivastava
6a7f25d30d Improve "llvm-nm -f sysv" output for Elf files
Specifically, compute and Print Type and Section columns.

This is a re-commit of rL354833, after fixing the Asan problem found a a buildbot.

Differential Revision: https://reviews.llvm.org/D59060


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355742 91177308-0d34-0410-b5e6-96231b3b80d8
2019-03-08 22:00:50 +00:00
Vlad Tsyrklevich
728bc80a2e Revert "Improve "llvm-nm -f sysv" output for Elf files"
This reverts commit r354833, it was causing ASan test failures on
sanitizer-x86_64-linux-fast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354849 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-26 07:04:56 +00:00
Sunil Srivastava
b34b0bf047 Improve "llvm-nm -f sysv" output for Elf files
Specifically, compute and Print Type and Section columns.

Differential Revision: https://reviews.llvm.org/D58263


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354833 91177308-0d34-0410-b5e6-96231b3b80d8
2019-02-26 00:19:39 +00:00
Chandler Carruth
6b547686c5 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
2019-01-19 08:50:56 +00:00
Vitaly Buka
a4da437c1d Use unique_ptr to hold MCInstrInfo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340654 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-24 21:03:35 +00:00
Joel Galenson
ddf089299b Use unique_ptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340642 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-24 19:40:35 +00:00
Joel Galenson
77a17afc92 Find PLT entries for x86, x86_64, and AArch64.
This adds a new method to ELFObjectFileBase that returns the symbols and addresses of PLT entries.

This design was suggested by pcc and eugenis in https://reviews.llvm.org/D49383.

Differential Revision: https://reviews.llvm.org/D50203

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340610 91177308-0d34-0410-b5e6-96231b3b80d8
2018-08-24 15:21:56 +00:00
Shiva Chen
10bc294458 [RISCV] Add ELFObjectFileBase::getRISCVFeatures let llvm-objdump could get RISCV target feature
llvm-objdump could get C feature by ELF::EF_RISCV_RVC e_flag,
so then we don't have to add -mattr=+c on the command line.

Differential Revision: https://reviews.llvm.org/D42629

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324058 91177308-0d34-0410-b5e6-96231b3b80d8
2018-02-02 06:01:02 +00:00
Rafael Espindola
f1e44dfc90 Move getPlatformFlags to ELFObjectFileBase and simplify.
This removes a few std::error_code results that were ignored on every
call.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323674 91177308-0d34-0410-b5e6-96231b3b80d8
2018-01-29 18:27:30 +00:00
Rafael Espindola
5c1b443509 Make the ELFObjectFile constructor private.
This forces every user to use the new create method that returns an
Expected. This in turn propagates better error messages.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315371 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-10 21:21:16 +00:00
Rafael Espindola
a1fdc616ec Simplify. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315364 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-10 21:03:46 +00:00
Rafael Espindola
e2d20cb260 Convert two uses of ErrorOr to Expected.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315354 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-10 20:00:07 +00:00
Florian Hahn
ace970e5d2 [Triple] Add isThumb and isARM functions.
Summary:
isThumb returns true for Thumb triples (little and big endian), isARM
returns true for ARM triples (little and big endian).
There are a few more checks using arm/thumb that are not covered by
those functions, e.g. that the architecture is either ARM or Thumb
(little endian) or ARM/Thumb little endian only.

Reviewers: javed.absar, rengolin, kristof.beyls, t.p.northover

Reviewed By: rengolin

Subscribers: llvm-commits, aemerson

Differential Revision: https://reviews.llvm.org/D34682

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310781 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-12 17:40:18 +00:00
Zachary Turner
19ca2b0f9d 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304864 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-07 03:48:56 +00:00
Chandler Carruth
e3e43d9d57 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).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304787 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-06 11:49:48 +00:00
Eugene Zelenko
c581c4ffc9 [Object] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301275 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-24 23:21:38 +00:00
Sam Parker
56e5bde913 [ARM] Create SubtargetFeatures from build attrs
An ELFObjectFile can now create SubtargetFeatures from the available
ARM build attributes, in a similar manner to MIPS. I've moved the
MIPS code into its own function and the ARM handler also has a
separate function.

Differential Revision: https://reviews.llvm.org/D28291



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292403 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-18 15:52:11 +00:00
Sam Parker
aa96763063 [ARM] Create objdump subtarget from build attrs
Enable an ELFObjectFile to read the its arm build attributes to
produce a target triple with a specific ARM architecture.
llvm-objdump now uses this functionality to automatically produce
a more accurate target.

Differential Revision: https://reviews.llvm.org/D28769


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292366 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-18 13:52:12 +00:00
Ivan Krasin
d6d6b83a0b Revert r291903 and r291898. Reason: they break check-lld on the bots.
Summary:
Revert [ARM] Fix ubig32_t read in ARMAttributeParser

Now using support functions to read data instead of trying to
perform casts.
===========================================================

Revert [ARM] Enable objdump to construct triple for ARM

Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.

Subscribers: llvm-commits, samparker, aemerson, mgorny

Differential Revision: https://reviews.llvm.org/D28683

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291911 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-13 16:45:15 +00:00
Sam Parker
6968dd2f43 [ARM] Enable objdump to construct triple for ARM
Now that The ARMAttributeParser has been moved into the library,
it has been modified so that it can parse the attributes without
printing them and stores them in a map. ELFObjectFile now queries
the attributes to fill out the architecture details of a provided
triple for 'arm' and 'thumb' targets. llvm-objdump uses this new
functionality.

Differential Revision: https://reviews.llvm.org/D28281



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291898 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-13 11:04:21 +00:00
Daniel Sanders
0b8fc77698 [llvm-objdump] Support detection of feature bits from the object and implement this for Mips.
Summary:
The Mips implementation only covers the feature bits described by the ELF
e_flags so far. Mips stores additional feature bits such as MSA in the
.MIPS.abiflags section.

Also fixed a small bug this revealed where microMIPS wouldn't add the
EF_MIPS_MICROMIPS flag when using -filetype=obj.

Reviewers: echristo, rafael

Subscribers: rafael, mehdi_amini, dsanders, sdardis, llvm-commits

Differential Revision: http://reviews.llvm.org/D21125

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272880 91177308-0d34-0410-b5e6-96231b3b80d8
2016-06-16 09:17:03 +00:00
Alexey Samsonov
196340cc6c [Object, ELF] Don't assert on invalid magic in createELFObjectFile.
Instead, return a proper error code from factory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239116 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-04 23:14:43 +00:00
Alexey Samsonov
1ea35c2d52 [Object, ELF] Don't call llvm_unreachable() from createELFObjectFile.
Instead, return a proper error code from factory.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239113 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-04 22:58:25 +00:00
Rafael Espindola
9751e35f20 Simplify now that we always use an alignment of 2 for ELF files.
This saves 123144 bytes out of llvm-nm on powerpc64le.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238824 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-02 12:05:27 +00:00
Rafael Espindola
548f2b6e8f Don't own the buffer in object::Binary.
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.

Keeping this ownership would make supporting IR inside native objects
particularly painful.

This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.

This patch introduces a few new types.

* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
  This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
  for convenience functions that take a filename and return both the
  buffer and the Binary using that buffer.

The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216002 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-19 18:44:46 +00:00
Rafael Espindola
db7cdc8eb0 Add a non-templated ELFObjectFileBase class.
Use it to implement some ELF only virtual interfaces instead of using error
prone series of dyn_casts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215838 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-17 17:52:10 +00:00
Rafael Espindola
79002da926 Use std::unique_ptr to make the ownership explicit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214377 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-31 03:12:45 +00:00
Rafael Espindola
db8cb2223d This only needs a StringRef. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212371 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-05 11:38:52 +00:00
Rafael Espindola
8659ad443a Replace two release calls with std::move. I missed this on the previous commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211597 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-24 14:25:17 +00:00
Rafael Espindola
0d50598d71 Pass a unique_ptr<MemoryBuffer> to the constructors in the Binary hierarchy.
Once the objects are constructed, they own the buffer. Passing a unique_ptr
makes that clear.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211595 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-24 13:56:32 +00:00
Rafael Espindola
b138caba43 Pass a std::unique_ptr& to the create??? methods is lib/Object.
This makes the buffer ownership on error conditions very natural. The buffer
is only moved out of the argument if an object is constructed that now
owns the buffer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211546 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-23 22:00:37 +00:00
Rafael Espindola
1f659329b6 Make ObjectFile and BitcodeReader always own the MemoryBuffer.
This allows us to just use a std::unique_ptr to store the pointer to the buffer.
The flip side is that they have to support releasing the buffer back to the
caller.

Overall this looks like a more efficient and less brittle api.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211542 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-23 21:53:12 +00:00
Rafael Espindola
a841620f66 Fix a memory leak in the error path.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211184 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-18 17:07:15 +00:00
Rafael Espindola
7f2f94faeb Fix pr17056.
This makes llvm-nm ignore members that are not sufficiently aligned for
lib/Object to handle.

These archives are invalid. GNU AR is able to handle this, but in general
just warns about broken archive members.

We should probably start warning too, but for now just make sure llvm-nm
exits with an 0.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211036 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-16 16:41:00 +00:00
Rafael Espindola
4e2b922131 Remove 'using std::errro_code' from lib.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210871 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-13 02:24:39 +00:00
Rafael Espindola
5c792faa0e Don't use 'using std::error_code' in include/llvm.
This should make sure that most new uses use the std prefix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-12 21:46:39 +00:00
Ahmed Charles
f4ccd11075 Replace OwningPtr<T> with std::unique_ptr<T>.
This compiles with no changes to clang/lld/lldb with MSVC and includes
overloads to various functions which are used by those projects and llvm
which have OwningPtr's as parameters. This should allow out of tree
projects some time to move. There are also no changes to libs/Target,
which should help out of tree targets have time to move, if necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203083 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-06 05:51:42 +00:00
Ahmed Charles
1a6eca243f [C++11] Replace OwningPtr::take() with OwningPtr::release().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202957 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 10:19:29 +00:00
Rafael Espindola
584fe2db6a Make ObjectFile ownership of the MemoryBuffer optional.
This allows llvm-ar to mmap the input files only once.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200040 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 21:32:21 +00:00
Rafael Espindola
3d218156f8 Be a bit more consistent about using ErrorOr when constructing Binary objects.
The constructors of classes deriving from Binary normally take an error_code
as an argument to the constructor. My original intent was to change them
to have a trivial constructor and move the initial parsing logic to a static
method returning an ErrorOr. I changed my mind because:

* A constructor with an error_code out parameter is extremely convenient from
  the implementation side. We can incrementally construct the object and give
  up when we find an error.
* It is very efficient when constructing on the stack or when there is no
  error. The only inefficient case is where heap allocating and an error is
  found (we have to free the memory).

The result is that this is a much smaller patch. It just standardizes the
create* helpers to return an ErrorOr.

Almost no functionality change: The only difference is that this found that
we were trying to read past the end of COFF import library but ignoring the
error.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199770 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-21 23:06:54 +00:00