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
llvm-svn: 291898
Decompressor intention is to reduce duplication of code.
Currently LLD has own implementation of decompressor
for compressed debug sections.
This class helps to avoid it and share the code.
LLD patch for reusing it is D28106
Differential revision: https://reviews.llvm.org/D28105
llvm-svn: 291675
The Mach-O command line flag like "-arch armv7m" does not match the
arch name part of its llvm Triple which is "thumbv7m-apple-darwin”.
I think the best way to fix this is to have
llvm::object::MachOObjectFile::getArchTriple() optionally return the
name of the Mach-O arch flag that would be used with -arch that
matches the CPUType and CPUSubType. Then change
llvm::object::MachOUniversalBinary::ObjectForArch::getArchTypeName()
to use that and change it to getArchFlagName() as the type name is
really part of the Triple and the -arch flag name is a Mach-O thing
for a specific Triple with a specific Mcpu value.
rdar://29663637
llvm-svn: 290001
Summary: The relocation is missing mask so an address that has non-zero bits in 47:43 may overwrite the register number. (Frequently shows up as target register changed to `xzr`....)
Reviewers: t.p.northover, lhames
Subscribers: davide, aemerson, rengolin, llvm-commits
Differential Revision: https://reviews.llvm.org/D27609
llvm-svn: 289880
This allows us to remove a few uses of IRObjectFile::getSymbolGV() in
llvm-nm.
While here change host-dependent logic in llvm-nm to target-dependent
logic.
Differential Revision: https://reviews.llvm.org/D27075
llvm-svn: 288320
This class represents a symbol table built from in-memory IR. It provides
access to GlobalValues and should only be used if such access is required
(e.g. in the LTO implementation). We will eventually change IRObjectFile
to read from a bitcode symbol table rather than using ModuleSymbolTable,
so it would not be able to expose the module.
Differential Revision: https://reviews.llvm.org/D27073
llvm-svn: 288319
Summary:
When using thin archives, and processing the same archive multiple times, we were mangling existing entries. The root cause is that we were calling computeRelativePath() more than once. Here, we only call it when adding new members to an archive.
Note that D27218 changes the way thin archives are printed, and will break the new unit test included here. Depending on which one lands first, the other will need to be slightly modified.
Reviewers: rafael, davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D27217
llvm-svn: 288280
This is the first part of an effort to add wasm binary
support across all llvm tools.
Patch by Sam Clegg
Differential Revision: https://reviews.llvm.org/D26172
llvm-svn: 288251
Change the IRObjectFile symbol iterator to be a pointer into a vector of
PointerUnions representing either IR symbols or asm symbols.
This change is in preparation for a future change for supporting multiple
modules in an IRObjectFile. Although it causes an increase in memory
consumption, we can deal with that issue separately by introducing a bitcode
symbol table.
Differential Revision: https://reviews.llvm.org/D26928
llvm-svn: 287845
- teach RelocVisitor to recognize bpf relocations
- fix AsmInfo->PointerSize to make sure dwarf is emitted correctly
- add a test for the above
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 287521
This has two advantages:
1) We slowly move away from ErrorOr to the new handling interface,
in the hope of having an uniform error handling in LLVM, eventually.
2) We're starting to have *meaningful* error messages for invalid
object ELF files, rather than a generic "parse error". At some point
we should include also the offset to improve the quality of the
diagnostic.
llvm-svn: 287081
Sometimes, llvm-symbolizer gives wrong results due to incorrect sizes of some symbols. The reason for that was an incorrectly sorted array in computeSymbolSizes. The comparison function used subtraction of unsigned types, which is incorrect. Let's change this to return explicit -1 or 1.
Differential Revision: https://reviews.llvm.org/D26537
llvm-svn: 287028
The philosophy of the error checking in libObject for Mach-O files
is that the constructor will check the load commands so for their
tables the offsets and sizes are properly contained in the file.
But there is no checking of the entries of any of the tables.
For the contents of the tables themselves the methods accessing
the contents of the entries return errors as needed. In some
cases this however makes it difficult or cumbersome to produce
a good error message which would include the tool name, file name,
archive member, and name of the architecture of a slice of a universal file
the error occurred in.
So idea is that there will be a method to check a table which can
be called up front before using it allowing a good error message
to be produced before a table is used. And if only verification of
the Mach-O file and its tables are wanted a new possible method
checkAllTables() could be added to call all of the methods to
check all the tables at some time when such methods exist.
The checkSymbolTable() is the first of such methods to check
one of the Mach-O file tables. This method initially will used in
llvm-objdump’s DisassembleMachO() routine before it gets the
section and symbol information. As if there are problems with
the symbol table currently the error is first encountered by the
bool operator() in the SymbolSorter() struct which passed to
std::sort(). In this case there is no context as to the file name
the symbol which results a poor error message:
LLVM ERROR: truncated or malformed object (bad string index: 22 for symbol at index 1)
with the added call to the checkSymbolTable() method the
error message includes the tool name and file name:
llvm-objdump: 'macho-invalid-symbol-strx': truncated or malformed object (bad string table index: 22 past the end of string table, for symbol at index 1)
llvm-svn: 286887
The functions getBitcodeTargetTriple(), isBitcodeContainingObjCCategory(),
getBitcodeProducerString() and hasGlobalValueSummary() now return errors
via their return value rather than via the diagnostic handler.
To make this work, re-implement these functions using non-member functions
so that they can be used without the LLVMContext required by BitcodeReader.
Differential Revision: https://reviews.llvm.org/D26532
llvm-svn: 286623
All error checking now happens when the information is needed. The
only thing left is the minimum size of the buffer and that can be just
a precondition. I will add an ErrorOr create method in a followup
commit.
Also don't store a pointer to the Header, since it is just a trivial
cast.
llvm-svn: 285961
That is consistent with other methods around
and helps to handle error on a caller side.
Differential revision: https://reviews.llvm.org/D26247
llvm-svn: 285886
Otherwise we set it always to zero, which is not correct,
and we assert inside alignTo (Assertion failed:
Align != 0u && "Align can't be 0.").
Differential Revision: https://reviews.llvm.org/D26173
llvm-svn: 285841
The description in the ELF spec is just
---------------------------
If the section name string table section index is greater than or
equal to SHN_LORESERVE (0xff00), this member has the value SHN_XINDEX
(0xffff) and the actual index of the section name string table section
is contained in the sh_link field of the section header at index 0.
---------------------------
So we only have to check for it being SHN_XINDEX. Also, sh_link is
always 32 bits, so don't return an uintX_t.
llvm-svn: 285747
Add the necessary definitions for RISC-V ELF files, including relocs. Also
make necessary trivial change to ELFYaml, llvm-objdump, and llvm-readobj in
order to work with RISC-V ELFs.
Differential Revision: https://reviews.llvm.org/D23557
llvm-svn: 285708
with fix: edited invalid-section-index2.elf input to pass the new check and
fail on the same place it was intended to fail.
Original commit message:
Elf.h already has code checking that section table does not go past end of file.
Problem is that this check may not work on values greater than UINT64_MAX / Header->e_shentsize
because of calculation overflow.
Parch fixes the issue.
Differential revision: https://reviews.llvm.org/D25432
llvm-svn: 285586
Elf.h already has code checking that section table does not go past end of file.
Problem is that this check may not work on values greater than UINT64_MAX / Header->e_shentsize
because of calculation overflow.
Parch fixes the issue.
Differential revision: https://reviews.llvm.org/D25432
llvm-svn: 285285
Revealed using "id_000038,sig_11,src_000015,op_havoc,rep_16" from PR30540,
when sh_size was 0, crash happened.
Differential revision: https://reviews.llvm.org/D25091
llvm-svn: 285282
Summary:
Most of the changes are very straight-forward. The only choice I had to make was
to use second-precision time points in the Archive classes. I did this because
the archive files use that precision in the on-disk representation anyway.
Reviewers: rafael, zturner
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25773
llvm-svn: 284974
Summary:
This is a follow-up to D25416. It removes all usages of TimeValue from
llvm/Support library (except for the actual TimeValue declaration), and replaces
them with appropriate usages of std::chrono. To facilitate this, I have added
small utility functions for converting time points and durations into appropriate
OS-specific types (FILETIME, struct timespec, ...).
Reviewers: zturner, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25730
llvm-svn: 284966
All of these existed because MSVC 2013 was unable to synthesize default
move ctors. We recently dropped support for it so all that error-prone
boilerplate can go.
No functionality change intended.
llvm-svn: 284721
Without this check LLD crashes when SHT_GROUP section has invalid symbol index
because of next code:
template <class ELFT>
StringRef elf::ObjectFile<ELFT>::getShtGroupSignature(const Elf_Shdr &Sec) {
..
const Elf_Sym *Sym = Obj.getSymbol(Symtab, Sec.sh_info);
..
}
If sh_info is too large, &Symbols[Index] just asserts.
No testcases provided because llvm-objdump/llvm-readelf does
not use getSymbol() function.
I`ll commit testcase for LLD separatelly.
Differential revision: https://reviews.llvm.org/D25516
llvm-svn: 284702
Patch checks that section pointer is aligned properly.
This should be done before getStringTable() call.
Differential revision: https://reviews.llvm.org/D25462
llvm-svn: 284387
With fix: hex edited the precompiled inputs from another testcases to pass new checks.
Original commit message:
[Object/ELF] - Check that e_shnum is null when e_shoff is.
Spec says (http://www.sco.com/developers/gabi/1998-04-29/ch4.eheader.html) :
e_shnum
This member holds the number of entries in the section header table. Thus the product of e_shentsize and e_shnum gives the section header table's size in bytes. If a file has no section header table, e_shnum holds the value zero.
Revealed using "id_000037,sig_11,src_000015,op_havoc,rep_8" from PR30540
That was the reason of crash in lld on incorrect input file.
Binary reduced using afl-min.
Differential revision: https://reviews.llvm.org/D25090
llvm-svn: 284374
Spec says (http://www.sco.com/developers/gabi/1998-04-29/ch4.eheader.html) :
e_shnum
This member holds the number of entries in the section header table. Thus the product of e_shentsize and e_shnum gives the section header table's size in bytes. If a file has no section header table, e_shnum holds the value zero.
Revealed using "id_000037,sig_11,src_000015,op_havoc,rep_8" from PR30540
That was the reason of crash in lld on incorrect input file.
Binary reduced using afl-min.
Differential revision: https://reviews.llvm.org/D25090
llvm-svn: 284371
If object has wrong (large) string table index and
also incorrect large value for amount of sections in total,
then section index passes the check:
if (Index >= getNumSections())
return object_error::invalid_section_index;
But result pointer then is far after end of file data, what
result in a crash.
Differential revision: https://reviews.llvm.org/D25081
llvm-svn: 284369
Bot does not like it: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/17075
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Object/invalid.test:70:32: error: expected string not found in input
INVALID-SEC-ADDRESS-ALIGNMENT: Invalid address alignment of section headers
^
<stdin>:1:1: note: scanning from here
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Object/ELF.h:412:7: runtime error: upcast of misaligned address 0x000002d8b899 for type 'llvm::object::Elf_Shdr_Impl<llvm::object::ELFType<llvm::support::endianness::little, true> >', which requires 2 byte alignment
^
<stdin>:1:125: note: possible intended match here
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Object/ELF.h:412:7: runtime error: upcast of misaligned address 0x000002d8b899 for type 'llvm::object::Elf_Shdr_Impl<llvm::object::ELFType<llvm::support::endianness::little, true> >', which requires 2 byte alignment
llvm-svn: 283858
sections_begin() may return unalignment pointer when Header->e_shoff isinvalid.
That may result in a crash in clients, for example we have one in LLD:
assert((PtrWord & ~PointerBitMask) == 0 &&
"Pointer is not sufficiently aligned");
fails when trying to push_back Elf_Shdr* (unaligned) into TinyPtrVector.
Patch forces check for alignment of Header->e_shoff.
Differential revision: https://reviews.llvm.org/D25368
llvm-svn: 283740
To be default constructible, Archive::child_iterator needs to be able to
construct an Archive::Child with a null parent, however Archive::Child's
constructor always dereferenced its Parent argument to compute the remaining
archive size. This commit fixes Archive::Child's constructor to only do the
size calculation when the parent is non-null.
llvm-svn: 283387
Previously code would access invalid memory and may crash,
patch fixes the issue.
Differential revision: https://reviews.llvm.org/D25187
llvm-svn: 283204
When using broken input object found using AFL,
getExtendedSymbolTableIndex() crashed because ShndxTable
was empty as object does not contain SHT_SYMTAB_SHNDX section.
Differential revision: https://reviews.llvm.org/D25189
llvm-svn: 283196
Summary:
It was previously not possible for tools to use solely the stackmap
information emitted to reconstruct the return addresses of callsites in
the map, which is necessary to use the information to walk a stack. This
patch adds per-function callsite counts when emitting the stackmap
section in order to resolve the problem. Note that this slightly alters
the stackmap format, so external tools parsing these maps will need to
be updated.
**Problem Details:**
Records only store their offset from the beginning of the function they
belong to. While these records and the functions are output in program
order, it is not possible to determine where the end of one function's
records are without the callsite count when processing the records to
compute return addresses.
Patch by Kavon Farvardin!
Reviewers: atrick, ributzka, sanjoy
Subscribers: nemanjai
Differential Revision: https://reviews.llvm.org/D23487
llvm-svn: 281532
When binaries are compressed by UPX, information about symbol table
offset and symbol count remain unchanged (but became invalid due to
compression).
This causes failure in the constructor and the rest of the binary cannot
be processed.
Instead, reset symbol related information (symbol/string table pointers,
sizes) - this should disable the related iterators and functions while
the rest of the binary can still be processed.
Patch by Bandzi Michal!
llvm-svn: 280147
The DebugDirectory contains a pointer to the CodeView info structure which is a
derivative of the OMF debug directory. The structure has evolved a bit over
time, and PDB 2.0 used a slightly different definition from PDB 7.0. Both of
these are specific to CodeView and not COFF. Reflect this by moving the
structure definitions into the DebugInfo/CodeView headers. Define a generic
DebugInfo union type that can be used to pass around a reference to the
DebugInfo irrespective of the versioning. NFC.
llvm-svn: 278075
changing them to Expected<> to allow them to pass through llvm Errors.
No functional change.
This commit by itself will break the next lld builds. I’ll be committing the
matching change for lld immediately next.
llvm-svn: 277656
This reverts commit the revert commit r277627. The build errors
mentioned in r277627 were likely caused by an unclean build directory.
Sorry for the noise.
llvm-svn: 277630
This reverts commit r277540. It breaks the build with:
../lib/Object/Archive.cpp:264:41: error: return type of out-of-line definition of 'llvm::object::ArchiveMemberHeader::getUID' differs from that in the declaration
Expected<unsigned> ArchiveMemberHeader::getUID() const {
~~~~~~~~~~~~~~~~~~ ^
include/llvm/Object/Archive.h:53:12: note: previous declaration is here
unsigned getUID() const;
~~~~~~~~ ^
llvm-svn: 277627
We had import_directory_table_entry and
coff_import_directory_table_entry, remove one. Also, factor out the
logic which determins if a descriptor is a terminator.
llvm-svn: 277296
As mentioned in commit log for r276686 this next step is adding a new
method in the ArchiveMemberHeader class to get the full name that
does proper error checking, and can be use for error messages.
To do this the name of ArchiveMemberHeader::getName() is changed to
ArchiveMemberHeader::getRawName() to be consistent with
Archive::Child::getRawName(). Then the “new” method is the addition
of a new implementation of ArchiveMemberHeader::getName() which gets
the full name and provides proper error checking. Which is mostly a rewrite
of what was Archive::Child::getName() and cleaning up incorrect uses of
llvm_unreachable() in the code which were actually just cases of errors
in the input Archives.
Then Archive::Child::getName() is changed to return Expected<> and use
the new implementation of ArchiveMemberHeader::getName() .
Also needed to change Archive::getMemoryBufferRef() with these
changes to return Expected<> as well to propagate Errors up.
As well as changing Archive::isThinMember() to return Expected<> .
llvm-svn: 277177
I consulted with Lang Hames on this work, and the goal was to add a bit
of "where" in the archive the error occurred along with what the error was.
So this step changes ArchiveMemberHeader into a class with a pointer
to the archive header and the parent archive. Which allows the methods
in the ArchiveMemberHeader to determine which member the header is
for to include that information in the error message.
For this first step the "where" is just the offset to the member in the
archive. The next step will be a new method on ArchiveMemberHeader
to get the full name, if possible, to be use in the error message. Which
will now be possible as ArchiveMemberHeader contains a pointer to
the Archive with its string table and its size, etc. so the full name can
be determined from the header if it is valid.
Also this change adds the missing checks the archive header is actually
contained in the buffer and is not truncated, as well as if the terminating
characters are correct in the header.
And changes one error message in Archive::Child::getNext() where the
name or offset to member is now added.
llvm-svn: 276686
This allows ErrorAsOutParameter to work better with "optional" errors. For
example, consider a function where for certain input values it is known that
the function can't fail. This can now be written as:
Result foo(Arg X, Error *Err) {
ErrorAsOutParameter EAO(Err);
if (<Error Condition>) {
if (Err)
*Err = <report error>;
else
llvm_unreachable("Unexpected failure!");
}
}
Rather than having to construct an ErrorAsOutParameter under every conditional
where Err is known to be non-null.
llvm-svn: 276430
This step builds on Lang Hames work to change Archive::child_iterator
for better interoperation with Error/Expected. Building on that it is now
possible to return an error message when the size field of an archive
contains non-decimal characters.
llvm-svn: 276025
The same value for EM_BPF is being propagated to glibc,
elfutils, and binutils.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
llvm-svn: 275633
See http://reviews.llvm.org/D22079
Changes the Archive::child_begin and Archive::children to require a reference
to an Error. If iterator increment fails (because the archive header is
damaged) the iterator will be set to 'end()', and the error stored in the
given Error&. The Error value should be checked by the user immediately after
the loop. E.g.:
Error Err;
for (auto &C : A->children(Err)) {
// Do something with archive child C.
}
// Check the error immediately after the loop.
if (Err)
return Err;
Failure to check the Error will result in an abort() when the Error goes out of
scope (as guaranteed by the Error class).
llvm-svn: 275316
The NewArchiveIterator class has a problem: it requires too much context. Any
memory buffers added to the archive must be stored within an Archive::Member,
which must have an associated Archive. This makes it harder than necessary
to create new archive members (or new archives entirely) from scratch using
memory buffers.
This patch replaces NewArchiveIterator with a NewArchiveMember class that
stores just the memory buffer and the information that goes into the archive
member header.
Differential Revision: http://reviews.llvm.org/D21721
llvm-svn: 274183
and its clients to use the new llvm::Error model for error handling.
Changed getAsArchive() from ErrorOr<...> to Expected<...> so now all
interfaces there use the new llvm::Error model for return values.
In the two places it had if (!Parent) this is actually a program error so changed
from returning errorCodeToError(object_error::parse_failed) to calling
report_fatal_error() with a message.
In getObjectForArch() added error messages to its two llvm::Error return values
instead of returning errorCodeToError(object_error::arch_not_found) with no
error message.
For the llvm-obdump, llvm-nm and llvm-size clients since the only binary files in
Mach-O Universal Binaries that are supported are Mach-O files or archives with
Mach-O objects, updated their logic to generate an error when a slice contains
something like an ELF binary instead of ignoring it. And added a test case for
that.
The last error stuff to be cleaned up for libObject’s MachOUniversalBinary is
the use of errorOrToExpected(Archive::create(ObjBuffer)) which needs
Archive::create() to be changed from ErrorOr<...> to Expected<...> first,
which I’ll work on next.
llvm-svn: 274079
allow a good error message to be produced.
I added the one test case that the object file tools could produce an error
message. The other two errors can’t be triggered if the input file is passed
through sys::fs::identify_magic(). But the malformedError("bad magic number")
does get triggered by the logic in llvm-dsymutil when dealing with a normal
Mach-O file. The other "File too small ..." error would take a logic error
currently to produce and is not tested for.
llvm-svn: 273946
The last import is the penultimate entry, the last entry is nulled out.
Data beyond the null entry should not be considered to hold import
entries.
This fixes PR28302.
N.B. I am working on a reduced testcase, the one in PR28302 is too
large.
llvm-svn: 273790
This patch adds round-trip support for MachO Universal binaries to obj2yaml and yaml2obj. Universal binaries have a header and list of architecture structures, followed by a the individual object files at specified offsets.
llvm-svn: 273719
a good error message to be produced.
This is nearly the last libObject interface that used ErrorOr and the last one
that appears in llvm/include/llvm/Object/MachO.h . For Mach-O objects this is
just a clean up because it’s version of getSymbolAddress() can’t return an
error.
I will leave it to the experts on COFF and ELF to actually add meaning full
error messages in their tests if they wish. And also leave it to these experts
to change the last two ErrorOr interfaces in llvm/include/llvm/Object/ObjectFile.h
for createCOFFObjectFile() and createELFObjectFile() if they wish.
Since there are no test cases for COFF and ELF error cases with respect to
getSymbolAddress() in the test suite this is no functional change (NFC).
llvm-svn: 273701
Darwin added support in its Xcode 8.0 tools (released in the beta) for universal
files where offsets and sizes for the objects are 64-bits to allow support for
objects contained in universal files to be larger then 4gb. The change is very
straight forward. There is a new magic number that differs by one bit, much
like the 64-bit Mach-O files. Then there is a new structure that follow the
fat_header that has the same layout but with the offset and size fields using
64-bit values instead of 32-bit values.
rdar://26899493
llvm-svn: 273207
Darwin added support in its Xcode 8.0 tools (released in the beta) for static
library table of contents with 64-bit offsets to the archive members. The
change is very straight forward. The table of contents member is named
___.SYMDEF_64 or "___.SYMDEF_64 SORTED" and same layout is used but with
fields using 64 bit values instead of 32 bit values.
rdar://26869808
llvm-svn: 273058
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
llvm-svn: 272880
The data strucutre in the new FPO stream is described in the
PE/COFF spec. There is one record per function if frame pointer
is omitted.
Differential Revision: http://reviews.llvm.org/D20999
llvm-svn: 271926
Summary:
Previously we would try to load PDBs for every PE executable we tried to
symbolize. If that failed, we would fall back to DWARF. If there wasn't
any DWARF, we'd print mostly useless symbol information using the export
table.
With this change, we only try to load PDBs for executables that claim to
have them. If that fails, we can now print an error rather than falling
back silently. This should make it a lot easier to diagnose and fix
common symbolization issues, such as not having DIA or not having a PDB.
Reviewers: zturner, eugenis
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D20982
llvm-svn: 271725
This directory is used to find if there is a PDB associated with an
executable. I plan to use this functionality to teach llvm-symbolizer
whether it should use DIA or DWARF to symbolize a given DLL.
Reviewers: majnemer
Differential Revision: http://reviews.llvm.org/D20885
llvm-svn: 271539
when the object is from a slice of a Mach-O Universal Binary use something like
"foo.o (for architecture i386)" as part of the error message when expected.
Also fixed places in these tools that were ignoring object file errors from
MachOUniversalBinary::getAsObjectFile() when the code moved on to see if
the slice was an archive.
To do this MachOUniversalBinary::getAsObjectFile() and
MachOUniversalBinary::getObjectForArch() were changed from returning
ErrorOr<...> to Expected<...> then that was threaded up to its users.
Converting these interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. To contain the changes for now the use of
errorToErrorCode() is still used in two places yet to be fully converted.
llvm-svn: 271332
Ensure that the unused fields are explicitly stated when defining the types.
Add some compile time assertions about the size requirements for the structure
types.
llvm-svn: 270663
Fix was:
1) Had to regenerate dwarfdump-test-zlib.elf-x86-64, dwarfdump-test-zlib-gnu.elf-x86-64
(because llvm-symbolizer-zlib.test uses that inputs for its purposes and failed).
2) Updated llvm-symbolizer-zlib.test (updated used call function address to match new files +
added one more check for newly created dwarfdump-test-zlib-gnu.elf-x86-64 binary input).
3) Updated comment in dwarfdump-test-zlib.cc.
Original commit message:
[llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style.
Before this llvm-dwarfdump only recognized zlib-gnu compression style of headers,
this patch adds support for zlib style.
It looks reasonable to support both styles for dumping,
even if we are not going to suport generating of deprecated gnu one.
Differential revision: http://reviews.llvm.org/D20470
llvm-svn: 270557
fix: forgot to commit the updated dwarfdump-test-zlib.elf-x86-64
Original commit message:
[llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style.
Before this llvm-dwarfdump only recognized zlib-gnu compression style of headers,
this patch adds support for zlib style.
It looks reasonable to support both styles for dumping,
even if we are not going to suport generating of deprecated gnu one.
Differential revision: http://reviews.llvm.org/D20470
llvm-svn: 270543
Before this llvm-dwarfdump only recognized zlib-gnu compression style of headers,
this patch adds support for zlib style.
It looks reasonable to support both styles for dumping,
even if we are not going to suport generating of deprecated gnu one.
Differential revision: http://reviews.llvm.org/D20470
llvm-svn: 270540
when the object is in an archive to use something like libx.a(foo.o) as part of
the error message.
Also changed llvm-objdump and llvm-size to be like llvm-nm and ignore non-object
files in archives and not produce any error message.
To do this Archive::Child::getAsBinary() was changed from ErrorOr<...> to
Expected<...> then that was threaded up to its users.
Converting this interface to Expected<> from ErrorOr<> does involve
touching a number of places. To contain the changes for now the use of
errorToErrorCode() is still used in one place yet to be fully converted.
Again there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values. So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comments for those.
llvm-svn: 269784
When updating an existing archive, llvm-ar opens the old archive into a
`MemoryBuffer`, does its thing, and writes the results to a temporary
file. That file is then renamed to the original archive filename, thus
replacing it with the updated contents. However, on Windows at least,
what would happen is that the `MemoryBuffer` for the old archive would
actually be an mmap'ed view of the file, so when it came time to do the
rename via Win32's `ReplaceFile`, it would succeed but would be unable
to fully replace the file since there would still be a handle open on
it; instead, the old version got renamed to a random temporary name and
left behind.
Patch by Cameron!
llvm-svn: 268916
part of the error message.
As the caller is the one that needs to add the name of where the "object file"
comes from to the error message as the object file could be in an archive, or
coming from a slice of a Mach-O universal file or a buffer created by a JIT.
In the cases of a Mach-O universal file the architecture name may or may not
also need to be printed which is up to the tool code. For example if the tool
code is only selecting the host architecture slice then that architecture name
is never printed.
This patch is the change to the libObject code and there will be follow on
commits for changes to the code for each tool.
llvm-svn: 268789
load commands.
The existing test case in test/Object/macho-invalid.test for
macho-invalid-too-small-segment-load-command has a cmdsize of 55, while
being too small also it is not a multiple of 4. So when that check is added
this test case will produce a different error. So I constructed a new test case
that will trigger the intended error.
I also changed the error message to be consistent with the other malformed Mach-O
file error messages which prints the load command index. I also removed both
object_error::macho_load_segment_too_small and
object_error::macho_load_segment_too_many_sections from Object/Error.h
as they are not needed and can just use object_error::parse_failed and let the
error message string distinguish the specific error.
llvm-svn: 268652
command has a size less than 8 bytes.
I think the existing test case in test/Object/macho-invalid.test for
macho64-invalid-too-small-load-command was trying to test for this but that
test case triggered a different error given how it was constructed. So I
constructed a new test case that would trigger this specific error.
I also changed the error message to be consistent with the other malformed Mach-O
file error messages. I also removed object_error::macho_small_load_command from
Object/Error.h as it is not needed and can just use object_error::parse_failed
and let the error message string distinguish the error.
llvm-svn: 268463
Produce another specific error message for a malformed Mach-O file when a symbol’s
section index is more than the number of sections. The existing test case in test/Object/macho-invalid.test
for macho-invalid-section-index-getSectionRawName now reports the error with the message indicating
that a symbol at a specific index has a bad section index and that bad section index value.
Again converting interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. Where the existing code reported the error with a
string message or an error code it was converted to do the same.
Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values. So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
"// TODO: Actually report errors helpfully" and a call something like
consumeError(NameOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.
llvm-svn: 268298
Only one consumer (llvm-objdump) actually cared about the fact that there were
two triples. Others were actively working around the fact that the Triple
returned by getArch might have been invalid. As for llvm-objdump, it needs to
be acutely aware of both Triples anyway, so being generic in the exposed API is
no benefit.
Also rename the version of getArch returning a Triple. Users were having to
pass an unwanted nullptr to disambiguate the two, which was nasty.
The only functional change here is that armv7m and armv7em object files no
longer crash llvm-objdump.
llvm-svn: 267249
This removes the interfaces added (and not yet complete) to support
lazy reading of summaries. This support is not expected to be needed
since we are moving to a model where the full index is only being
traversed in the thin link step, instead of the back ends.
(The second part of this that I plan to do next is remove the
GlobalValueInfo from the ModuleSummaryIndex - it was mostly needed to
support lazy parsing of summaries. The index can instead reference the
summary structures directly.)
llvm-svn: 267097
Produce another specific error message for a malformed Mach-O file when a symbol’s
string index is past the end of the string table. The existing test case in test/Object/macho-invalid.test
for macho-invalid-symbol-name-past-eof now reports the error with the message indicating
that a symbol at a specific index has a bad sting index and that bad string index value.
Again converting interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. Where the existing code reported the error with a
string message or an error code it was converted to do the same. There is some
code for this that could be factored into a routine but I would like to leave that for
the code owners post-commit to do as they want for handling an llvm::Error. An
example of how this could be done is shown in the diff in
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h which had a Check() routine
already for std::error_code so I added one like it for llvm::Error .
Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values. So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
“// TODO: Actually report errors helpfully” and a call something like
consumeError(NameOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.
Note there fixes needed to lld that goes along with this that I will commit right after this.
So expect lld not to built after this commit and before the next one.
llvm-svn: 266919
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
Produce the first specific error message for a malformed Mach-O file describing
the problem instead of the generic message for object_error::parse_failed of
"Invalid data was encountered while parsing the file”. Many more good error
messages will follow after this first one.
This is built on Lang Hames’ great work of adding the ’Error' class for
structured error handling and threading Error through MachOObjectFile
construction. And making createMachOObjectFile return Expected<...> .
So to to get the error to the llvm-obdump tool, I changed the stack of
these methods to also return Expected<...> :
object::ObjectFile::createObjectFile()
object::SymbolicFile::createSymbolicFile()
object::createBinary()
Then finally in ParseInputMachO() in MachODump.cpp the error can
be reported and the specific error message can be printed in llvm-objdump
and can be seen in the existing test case for the existing malformed binary
but with the updated error message.
Converting these interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. To contain the changes for now use of
errorToErrorCode() and errorOrToExpected() are used where the callers
are yet to be converted.
Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values. So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
“// TODO: Actually report errors helpfully” and a call something like
consumeError(ObjOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.
Note there is one fix also needed to lld/COFF/InputFiles.cpp that goes along
with this that I will commit right after this. So expect lld not to built
after this commit and before the next one.
llvm-svn: 265606
Without setting the flag there is no way to determine if a symbol
points to an arm or to a thumb function as the LSB of the address
masked out in all getter function.
Note: Currently the thumb flag is only used for MachO files so
adding a test to this change is not possible. It will be used
by the upcoming fix for llvm-objdump for disassembling thumb
functions what is easily testable.
Differential revision: http://reviews.llvm.org/D17956
llvm-svn: 265387
Instead of using a bit to detect if they are "dynamic", just look at
sh_link.
This is a simplification on its own, and will help with using
llvm-objdump in dynamic objects.
llvm-svn: 264624
method instead.
This is not quite a named constructor: Construction may fail, and
MachOObjectFiles are usually passed by unique_ptr anyway, so create
returns an Expected<std::unique_ptr<MachOObjectFile>>.
llvm-svn: 264469
in the test suite. While this is not really an interesting tool and option to run
on a Mach-O file to show the symbol table in a generic libObject format
it shouldn’t crash.
The reason for the crash was in MachOObjectFile::getSymbolType() when it was
calling MachOObjectFile::getSymbolSection() without checking its return value
for the error case.
What makes this fix require a fair bit of diffs is that the method getSymbolType() is
in the class ObjectFile defined without an ErrorOr<> so I needed to add that all
the sub classes. And all of the uses needed to be updated and the return value
needed to be checked for the error case.
The MachOObjectFile version of getSymbolType() “can” get an error in trying to
come up with the libObject’s internal SymbolRef::Type when the Mach-O symbol
symbol type is an N_SECT type because the code is trying to select from the
SymbolRef::ST_Data or SymbolRef::ST_Function values for the SymbolRef::Type.
And it needs the Mach-O section to use isData() and isBSS to determine if
it will return SymbolRef::ST_Data.
One other possible fix I considered is to simply return SymbolRef::ST_Other
when MachOObjectFile::getSymbolSection() returned an error. But since in
the past when I did such changes that “ate an error in the libObject code” I
was asked instead to push the error out of the libObject code I chose not
to implement the fix this way.
As currently written both the COFF and ELF versions of getSymbolType()
can’t get an error. But if isReservedSectionNumber() wanted to check for
the two known negative values rather than allowing all negative values or
the code wanted to add the same check as in getSymbolAddress() to use
getSection() and check for the error then these versions of getSymbolType()
could return errors.
At the end of the day the error printed now is the generic “Invalid data was
encountered while parsing the file” for object_error::parse_failed. In the
future when we thread Lang’s new TypedError for recoverable error handling
though libObject this will improve. And where the added // Diagnostic(…
comment is, it would be changed to produce and error message
like “bad section index (42) for symbol at index 8” for this case.
llvm-svn: 264187
In executable and shared object ELF files, relocations in the file contain the final virtual address rather than section offset so this is adjusted to display section offset.
Differential revision: http://reviews.llvm.org/D15965
llvm-svn: 263971
The PE TLS directory contains information about where the TLS data
resides in the image, what functions should be executed when threads are
created, etc.
llvm-svn: 263537
(Resubmitting after fixing missing file issue)
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.
A companion clang patch will immediately succeed this patch to reflect
this renaming.
llvm-svn: 263513
These types are defined in ELFFile, so in order to use them, you have
to write ELFFile<ELFT>::SomeType. But there seems to be no reason to have
ELFFile have these types. This patch allows you to write ELFT::SomeType
instead.
This simplifies libObject users.
This is an example: http://reviews.llvm.org/D18129http://reviews.llvm.org/D18130
llvm-svn: 263504
With the changes in r263275, there are now more than just functions in
the summary. Completed the renaming of data structures (started in
r263275) to reflect the wider scope. In particular, changed the
FunctionIndex* data structures to ModuleIndex*, and renamed related
variables and comments. Also renamed the files to reflect the changes.
A companion clang patch will immediately succeed this patch to reflect
this renaming.
llvm-svn: 263490
Summary:
This patch adds support for including a full reference graph including
call graph edges and other GV references in the summary.
The reference graph edges can be used to make importing decisions
without materializing any source modules, can be used in the plugin
to make file staging decisions for distributed build systems, and is
expected to have other uses.
The call graph edges are recorded in each function summary in the
bitcode via a list of <CalleeValueIds, StaticCount> tuples when no PGO
data exists, or <CalleeValueId, StaticCount, ProfileCount> pairs when
there is PGO, where the ValueId can be mapped to the function GUID via
the ValueSymbolTable. In the function index in memory, the call graph
edges reference the target via the CalleeGUID instead of the
CalleeValueId.
The reference graph edges are recorded in each summary record with a
list of referenced value IDs, which can be mapped to value GUID via the
ValueSymbolTable.
Addtionally, a new summary record type is added to record references
from global variable initializers. A number of bitcode records and data
structures have been renamed to reflect the newly expanded scope of the
summary beyond functions. More cleanup will follow.
Reviewers: joker.eph, davidxl
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D17212
llvm-svn: 263275
Summary:
Rename the section embeds bitcode from ".llvmbc,.llvmbc" to "__LLVM,__bitcode".
The new name matches MachO section naming convention.
Reviewers: rafael, pcc
Subscribers: davide, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D17388
llvm-svn: 262245
The dynamic table is also an array of a fixed structure, so it can be
represented with a DynReginoInfo.
No major functionality change. The extra error checking is covered by
existing tests with a broken dynamic program header.
Idea extracted from r260488. I did the extra cleanups.
llvm-svn: 261107
We used to keep both a section and a pointer to the first symbol.
The oddity of keeping a section for dynamic symbols is because there is
a DT_SYMTAB but no DT_SYMTABZ, so to print the table we have to find the
size via a section table.
The reason for still keeping a pointer to the first symbol is because we
want to be able to print relocation tables even if the section table is
missing (it is mandatory only for files used in linking).
With this patch we keep just a DynRegionInfo. This then requires
changing a few places that were asking for a Elf_Shdr but actually just
needed the first symbol.
The test change is to delete the program header pointer.
Now that we use the information of both DT_SYMTAB and .dynsym, we don't
depend on the sh_entsize of .dynsym if we see DT_SYMTAB.
Note: It is questionable if it is worth it putting the effort to report
broken sh_entsize given that in files with no section table we have to
assume it is sizeof(Elf_Sym), but that is for another change.
Extracted from r260488.
llvm-svn: 261099
Original messages:
Revert "[readobj] Handle ELF files with no section table or with no program headers."
Revert "[readobj] Dump DT_JMPREL relocations when outputting dynamic relocations."
r260489 depends on r260488 and among other issues r260488 deleted error
handling code.
llvm-svn: 260962
r260925 introduced a version of the *trim methods which is preferable
when trimming a single kind of character. Update all users in llvm.
llvm-svn: 260926
This adds support for finding the dynamic table and dynamic symbol table via
the section table or the program header table. If there's no section table an
attempt is made to figure out the length of the dynamic symbol table.
llvm-svn: 260488
A request has been made to the official registry, but an official value is
not yet available. This patch uses a temporary value in order to support
development. When an official value is recieved, the value of EM_WEBASSEMBLY
will be updated.
llvm-svn: 257517
There is no real reason the index has to have the concept of an
exporting Module. We should be able to have one single unique
instance of the Index, and it should be read-only after creation
for the whole ThinLTO processing.
The linker plugin should be able to process multiple modules (in
parallel or in sequence) with the same index.
The only reason the ExportingModule was present seems to be to
implement hasExportedFunctions() that is used by the Module linker
to decide what to do with the current Module.
For now I replaced it with a query to the map of Modules path to
see if this module was declared in the Index and consider that if
it is the case then it is probably exporting function.
On the long term the Linker interface needs to evolve and this
call should not be needed anymore.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 254581
Add a shared helper routine to read the function index from a file
and create/return the function index object. Use it in llvm-link and
llvm-lto.
llvm-svn: 253903
The LLVMContext was only used for Diagnostic. Pass a DiagnosticHandler
instead.
Differential Revision: http://reviews.llvm.org/D14794
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 253540
The needed lld matching changes to be submitted immediately next,
but this revision will cause lld failures with this alone which is expected.
This removes the eating of the error in Archive::Child::getSize() when the characters
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
These changes will require corresponding changes to the lld project. That will be
committed immediately after this change. But this revision will cause lld failures
with this alone which is expected.
llvm-svn: 252192
This reverts commit r251837, due to a number of bot failures of the form:
/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to
'llvm::object::FunctionIndexObjectFile::create(llvm::MemoryBufferRef,
llvm::LLVMContext&, llvm::Module const*, bool)'
/home/grosser/buildslave/perf-x86_64-penryn-O3-polly-fast/llvm.obj/tools/llvm-link/Release+Asserts/llvm-link.o:llvm-link.cpp:function
loadIndex(llvm::LLVMContext&, llvm::Module const*): error: undefined
reference to 'llvm::object::FunctionIndexObjectFile::takeIndex()'
I'm not sure why these are happening - I added Object to the requred
libraries in tools/llvm-link/LLVMBuild.txt and the LLVM_LINK_COMPONENTS
in tools/llvm-link/CMakeLists.txt. Confirmed for my build that these
symbols come out of libLLVMObject.a. What am I missing?
llvm-svn: 251841
Summary:
Support for necessary linkage changes and symbol renaming during
ThinLTO function importing.
Also includes llvm-link support for manually importing functions
and associated llvm-link based tests.
Note that this does not include support for intelligently importing
metadata, which is currently imported duplicate times. That support will
be in the follow-on patch, and currently is ignored by the tests.
Reviewers: dexonsmith, joker.eph, davidxl
Subscribers: tobiasvk, tejohnson, llvm-commits
Differential Revision: http://reviews.llvm.org/D13515
llvm-svn: 251837
This is a bit ugly, but has a few advantages:
* Archive is now easy to copy since there is no Archive -> Child -> Archive
loop.
* It makes it clear that we already checked for errors when finding the Child
data.
llvm-svn: 251750
Also adds a 'trivial' ELF file. This was generated by assembling
and linking a file with the symbol main which contains a single
return instruction.
llvm-svn: 251096
in the size field in the archive header for the member is not a number. To do this we
have all of the needed methods return ErrorOr to push them up until we get out of lib.
Then the tools and can handle the error in whatever way is appropriate for that tool.
So the solution is to plumb all the ErrorOr stuff through everything that touches archives.
This include its iterators as one can create an Archive object but the first or any other
Child object may fail to be created due to a bad size field in its header.
Thanks to Lang Hames on the changes making child_iterator contain an
ErrorOr<Child> instead of a Child and the needed changes to ErrorOr.h to add
operator overloading for * and -> .
We don’t want to use llvm_unreachable() as it calls abort() and is produces a “crash”
and using report_fatal_error() to move the error checking will cause the program to
stop, neither of which are really correct in library code. There are still some uses of
these that should be cleaned up in this library code for other than the size field.
Also corrected the code where the size gets us to the “at the end of the archive”
which is OK but past the end of the archive will return object_error::parse_failed now.
The test cases use archives with text files so one can see the non-digit character,
in this case a ‘%’, in the size field.
llvm-svn: 250906
Add a new command line switch, -gnu-hash-table, to print the content of that section.
Differential Revision: http://reviews.llvm.org/D13696
llvm-svn: 250291
ArchiveMemberHeader, suggestion by Rafael Espíndola.
Also The clang-x86-win2008-selfhost bot still does not like the
malformed-machos 00000031.a test, so removing it for now. All
the other bots are fine with it however.
llvm-svn: 250222
that caused aborts. This was because of the characters of the ‘Size’ field in
the archive header did not contain decimal characters.
rdar://22983603
llvm-svn: 250117
Summary:
Previously the relative address flag only affected PDB debug info. Now
both DIContext implementations always expect to be passed virtual
addresses. llvm-symbolizer is now responsible for adding ImageBase to
module offsets when --relative-offset is passed.
Reviewers: zturner
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12883
llvm-svn: 249784
Summary:
The bitcode format is described in this document:
https://drive.google.com/file/d/0B036uwnWM6RWdnBLakxmeDdOeXc/view
For more info on ThinLTO see:
https://sites.google.com/site/llvmthinlto
The first customer is ThinLTO, however the data structures are designed
and named more generally based on prior feedback. There are a few
comments regarding how certain interfaces are used by ThinLTO, and the
options added here to gold currently have ThinLTO-specific names as the
behavior they provoke is currently ThinLTO-specific.
This patch includes support for generating per-module function indexes,
the combined index file via the gold plugin, and several tests
(more are included with the associated clang patch D11908).
Reviewers: dexonsmith, davidxl, joker.eph
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13107
llvm-svn: 249270
This patch includes a fix for a llvm-readobj test. With this patch,
the tool does no longer print out COFF headers for the short import
file, but that's probably desirable because the header for the short
import file is dummy.
llvm-svn: 246283
While introducing support for MinVersionLoadCommand in llvm-readobj I noticed there's
no API to extract Major/Minor/Update components conveniently. Currently consumers
do the bit twiddling on their own, but this will change from now on.
I'll convert llvm-objdump (and llvm-readobj) in a later commit.
Differential Revision: http://reviews.llvm.org/D12282
Reviewed by: rafael
llvm-svn: 245938
With this we finally have an ELFFile that is O(1) to construct. This is helpful
for programs like lld which have to do their own section walk.
llvm-svn: 244510
In tree they are only used by llvm-readobj, but it is also used by
https://github.com/mono/CppSharp.
While at it, add some missing error checking.
llvm-svn: 244320
lld might end up using a small part of this, but it will be in a much
refactored form. For now this unblocks avoiding the full section scan in the
ELFFile constructor.
This also has a (very small) error handling improvement.
llvm-svn: 244282
Not every program needs this information.
In particular, it is necessary and sufficient for a static linker to scan the
section table.
llvm-svn: 242833
