Commit Graph

243 Commits

Author SHA1 Message Date
Greg Clayton 2520c9ebee Make a function to correctly extract the DW_AT_high_pc given the low pc value.
DWARF 4 and later supports encoding the PC as an address or as as offset from the low PC. Clients using DWARFDie should be insulated from how to extract the high PC value. This function takes care of extracting the form value and looking for the correct form.

Differential Revision: https://reviews.llvm.org/D27885

llvm-svn: 290131
2016-12-19 20:36:41 +00:00
Greg Clayton 52fe1f68c8 Add the ability to get attribute values as Optional<T>
When getting attributes it is sometimes nicer to use Optional<T> some of the time instead of magic values. I tried to cut over to only using the Optional values but it made many of the call sites very messy, so it makes sense the leave in the calls that can return a default value. Otherwise code that looks like this:

uint64_t CallColumn = Die.getAttributeValueAsAddress(DW_AT_call_line, 0);

Has to be turned into:

uint64_t CallColumn = 0;
if (auto CallColumnValue = Die.getAttributeValueAsAddress(DW_AT_call_line))
    CallColumn = *CallColumnValue;

The first snippet of code looks much better. But in cases where you want an offset that may or may not be there, the following code looks better:

if (auto StmtOffset = Die.getAttributeValueAsSectionOffset(DW_AT_stmt_list)) {
  // Use StmtOffset
}

Differential Revision: https://reviews.llvm.org/D27772

llvm-svn: 289731
2016-12-14 22:38:08 +00:00
Greg Clayton 1cbf3fa94a Switch functions that returned bool and filled in a DWARFFormValue arg with ones that return Optional<DWARFFormValue>
Differential Revision: https://reviews.llvm.org/D27737

llvm-svn: 289611
2016-12-13 23:20:56 +00:00
Greg Clayton c8c1032c0c Make a DWARFDIE class that can help avoid using the wrong DWARFUnit when extracting attributes
Many places pass around a DWARFDebugInfoEntryMinimal and a DWARFUnit. It is easy to get things wrong by using the wrong DWARFUnit with a DWARFDebugInfoEntryMinimal. This patch creates a DWARFDie class that contains the DWARFUnit and DWARFDebugInfoEntryMinimal objects so that they can't get out of sync. All attribute extraction has been moved out of DWARFDebugInfoEntryMinimal and into DWARFDie. DWARFDebugInfoEntryMinimal was also renamed to DWARFDebugInfoEntry.

DWARFDie objects are temporary objects that are used by clients and contain 2 pointers that you always need to have anyway. Keeping them grouped will avoid errors and simplify many of the attribute extracting APIs by not having to pass in a DWARFUnit.

Differential Revision: https://reviews.llvm.org/D27634

llvm-svn: 289565
2016-12-13 18:25:19 +00:00
David Blaikie 4aa8175a92 [dsymutil] Simplify a lazy-init condition/expression
llvm-svn: 288423
2016-12-01 22:04:16 +00:00
Greg Clayton 35630c3357 This change removes the dependency on DwarfDebug that was used for DW_FORM_ref_addr by making a new DIEUnit class in DIE.cpp.
The DIEUnit class represents a compile or type unit and it owns the unit DIE as an instance variable. This allows anyone with a DIE, to get the unit DIE, and then get back to its DIEUnit without adding any new ivars to the DIE class. Why was this needed? The DIE class has an Offset that is always the CU relative DIE offset, not the "offset in debug info section" as was commented in the header file (the comment has been corrected). This is great for performance because most DIE references are compile unit relative and this means most code that accessed the DIE's offset didn't need to make it into a compile unit relative offset because it already was. When we needed to emit a DW_FORM_ref_addr though, we needed to find the absolute offset of the DIE by finding the DIE's compile/type unit. This class did have the absolute debug info/type offset and could be added to the CU relative offset to compute the absolute offset. With this change we can easily get back to a DIE's DIEUnit which will have this needed offset. Prior to this is required having a DwarfDebug and required calling:

DwarfCompileUnit *DwarfDebug::lookupUnit(const DIE *CU) const;
Now we can use the DIEUnit class to do so without needing DwarfDebug. All clients now use DIEUnit objects (the DwarfDebug stack and the DwarfLinker). A follow on patch for the DWARF generator will also take advantage of this.

Differential Revision: https://reviews.llvm.org/D27170

llvm-svn: 288399
2016-12-01 18:56:29 +00:00
Chris Bieneman d22fa5091c [CMake] llvm-dsymutil depends on intrinsics_gen
DwarfLinker.cpp has the following include chain:

llvm/CodeGen/AsmPrinter.h
llvm/CodeGen/MachineFunctionPass.h
llvm/CodeGen/MachineFunction.h
llvm/CodeGen/MachineBasicBlock.h
llvm/CodeGen/MachineInstr.h
llvm/Analysis/AliasAnalysis.h
llvm/IR/CallSite.h
llvm/IR/Attributes.h
llvm/IR/Attributes.gen

This means llvm-dsymutil needs to depend on intrinsics_gen.

llvm-svn: 287419
2016-11-19 02:02:46 +00:00
Greg Clayton 6f6e4dbd5d Improve DWARF parsing speed by improving DWARFAbbreviationDeclaration
This patch gets a DWARF parsing speed improvement by having DWARFAbbreviationDeclaration instances know if they have a fixed byte size. If an abbreviation has a fixed byte size that can be calculated given a DWARFUnit, then parsing a DIE becomes two steps: parse ULEB128 abbrev code, and then add constant size to the offset.

This patch also adds a fixed byte size to each DWARFAbbreviationDeclaration::AttributeSpec so that attributes can quickly skip their values if needed without the need to lookup the fixed for size.

Notable improvements:

- DWARFAbbreviationDeclaration::findAttributeIndex() now returns an Optional<uint32_t> instead of a uint32_t and we no longer have to look for the magic -1U return value
- Optional<uint32_t> DWARFAbbreviationDeclaration::findAttributeIndex(dwarf::Attribute attr) const;
- DWARFAbbreviationDeclaration now has a getAttributeValue() function that extracts an attribute value given a DIE offset that takes advantage of the DWARFAbbreviationDeclaration::AttributeSpec::ByteSize
- bool DWARFAbbreviationDeclaration::getAttributeValue(const uint32_t DIEOffset, const dwarf::Attribute Attr, const DWARFUnit &U, DWARFFormValue &FormValue) const;
- A DWARFAbbreviationDeclaration instance can return a fixed byte size for itself so DWARF parsing is faster:
- Optional<size_t> DWARFAbbreviationDeclaration::getFixedAttributesByteSize(const DWARFUnit &U) const;
- Any functions that used to take a "const DWARFUnit *U" that would crash if U was NULL now take a "const DWARFUnit &U" and are only called with a valid DWARFUnit

Differential Revision: https://reviews.llvm.org/D26567

llvm-svn: 286924
2016-11-15 01:23:06 +00:00
Mehdi Amini 41af43092c Make the Error class constructor protected
This is forcing to use Error::success(), which is in a wide majority
of cases a lot more readable.

Differential Revision: https://reviews.llvm.org/D26481

llvm-svn: 286561
2016-11-11 04:28:40 +00:00
Pavel Labath 62d72041d4 [dsymutil] Replace TimeValue with TimePoint
Summary:
All changes are pretty straight-forward. I chose to use TimePoints with
second precision, as that is all that seems to be required here.

Reviewers: friss, zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25908

llvm-svn: 286358
2016-11-09 11:43:52 +00:00
Victor Leschuk e1156c2eb0 DebugInfo: make DW_TAG_atomic_type valid
DW_TAG_atomic_type was already included in Dwarf.defs and emitted correctly,
however Verifier didn't recognize it as valid.
Thus we introduce the following changes:

  * Make DW_TAG_atomic_type valid tag for IR and DWARF (enabled only with -gdwarf-5)
  * Add it to related docs
  * Add DebugInfo tests

Differential Revision: https://reviews.llvm.org/D26144

llvm-svn: 285624
2016-10-31 19:09:38 +00:00
David Majnemer f5c0689e92 SymbolRef::Type is not a bitfield and must be compared directly
Found by PVS-Studio.

llvm-svn: 285597
2016-10-31 17:11:23 +00:00
Greg Clayton cddab279f6 Modify DWARFFormValue to remember the DWARFUnit that it was decoded with.
Modifying DWARFFormValue to remember the DWARFUnit that it was encoded with can simplify the usage of instances of this class. Previously users would have to try and pass in the same DWARFUnit that was used to decode the form value and there was a possibility that a different DWARFUnit might be supplied to the functions that extract values (strings, CU relative references, addresses) and cause problems. This fixes this potential issue by storing the DWARFUnit inside the DWARFFormValue so that this mistake can't be made. Instances of DWARFFormValue are not stored permanently and are used as temporary values, so the increase in size of an instance of DWARFFormValue isn't a big deal. This makes decoding form values more bullet proof and is a change that will be used by future modifications.

https://reviews.llvm.org/D26052

llvm-svn: 285594
2016-10-31 16:46:02 +00:00
Benjamin Kramer 0eae9eccdf Remove duplicated default move ctors/move assign. No functional change.
llvm-svn: 285302
2016-10-27 15:23:44 +00:00
Justin Bogner b03fd12cef Replace "fallthrough" comments with LLVM_FALLTHROUGH
This is a mechanical change of comments in switches like fallthrough,
fall-through, or fall-thru to use the LLVM_FALLTHROUGH macro instead.

llvm-svn: 278902
2016-08-17 05:10:15 +00:00
David Majnemer 0d955d0bf5 Use the range variant of find instead of unpacking begin/end
If the result of the find is only used to compare against end(), just
use is_contained instead.

No functionality change is intended.

llvm-svn: 278433
2016-08-11 22:21:41 +00:00
Zachary Turner 9e91c28b71 Resubmit "Make YAML support SmallVector"
This resubmits a3770391c5fb64108d565e12f61dd77ce71b5b4f,
which was reverted due to breakages on non-Windows machines.

Due to differences in template instantiation rules on Microsoft
and non-Microsoft platforms, a member access restriction was
triggering on non-Microsoft compilers.  Previously, a friend
declaration for std::vector<> had been introduced into the
DebugMap class to make the member access restriction pass,
but the introduction of support for SmallVector<> meant that
an additional friend declaration would need to be added.

This didn't really make a lot of sense since the user of the
macro is probably only using one type (SmallVector<>, vector<>,
etc) and we could in theory add support for even more types
to this macro in the future (e.g. std::deque), so rather than
add another friend declaration, I just made the type being
referenced a public nested typedef instead of a private nested
typedef.

llvm-svn: 277888
2016-08-05 23:12:31 +00:00
Vedant Kumar 4031d9f80e Reapply "More fixes to get good error messages for bad archives."
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
2016-08-03 19:02:50 +00:00
Vedant Kumar bfb6072d84 Revert "More fixes to get good error messages for bad archives."
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
2016-08-03 18:44:32 +00:00
Kevin Enderby 395cc09444 More fixes to get good error messages for bad archives.
Fixed the last incorrect uses of llvm_unreachable() in the code
which were actually just cases of errors in the input Archives.

llvm-svn: 277540
2016-08-02 22:58:55 +00:00
Kevin Enderby f4586039f6 The next step along the way to getting good error messages for bad archives.
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
2016-07-29 17:44:13 +00:00
Joel Jones 373d7d30dd MC] Provide an MCTargetOptions to implementors of MCAsmBackendCtorTy, NFC
Some targets, notably AArch64 for ILP32, have different relocation encodings
based upon the ABI. This is an enabling change, so a future patch can use the
ABIName from MCTargetOptions to chose which relocations to use. Tested using
check-llvm.

The corresponding change to clang is in: http://reviews.llvm.org/D16538

Patch by: Joel Jones

Differential Revision: https://reviews.llvm.org/D16213

llvm-svn: 276654
2016-07-25 17:18:28 +00:00
Pete Cooper cadadaa1b3 Fix r276380 for targets without REALPATH.
This was a mistake in the layout of the code from r276380.  I moved the appropriate lines out of the #ifdef to fix it.

llvm-svn: 276382
2016-07-22 01:52:58 +00:00
Pete Cooper b2ba776aed Avoid dsymutil calls to getFileNameByIndex.
This change adds a hasFileAtIndex method. getChildDeclContext can first call this method, and if it returns true it knows it can then lookup the resolved path cache for the given file index. If we hit that cache then we don't even have to call getFileNameByIndex.

Running dsymutil against the swift executable built from github gives a 20% performance improvement without any change in the binary.

Differential Revision: https://reviews.llvm.org/D22655

Reviewed by friss.

llvm-svn: 276380
2016-07-22 01:41:32 +00:00
Lang Hames fc209623e9 [Object] Re-apply r275316 now that I have the corresponding LLD patch ready.
llvm-svn: 275361
2016-07-14 02:24:01 +00:00
Lang Hames ae610ab528 [Object] Revert r275316, Archive::child_iterator changes, while I update lld.
Should fix the bots broken by r275316.

llvm-svn: 275353
2016-07-14 00:37:04 +00:00
Lang Hames c2773e97d2 [Object] Change Archive::child_iterator for better interop with Error/Expected.
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
2016-07-13 21:13:05 +00:00
Kevin Enderby c60a321c6b Change Archive::create() from ErrorOr<...> to Expected<...> and update
its clients.

This commit will break the next lld builds.  I’ll be committing the matching
change for lld next.

llvm-svn: 274160
2016-06-29 20:35:44 +00:00
Kevin Enderby 1051909df1 Change all but the last ErrorOr<...> use for MachOUniversalBinary to Expected<...> to
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
2016-06-27 21:39:39 +00:00
Reid Kleckner b435735259 Change that to include MCMachObjectWriter.h
llvm-svn: 273511
2016-06-22 23:30:43 +00:00
Reid Kleckner c7a150619a Add one more missing MCObjectWriter.h include
llvm-svn: 273510
2016-06-22 23:28:12 +00:00
Richard Smith 2ad6d48b0c Search for llvm-symbolizer binary in the same directory as argv[0], before
looking for it along $PATH. This allows installs of LLVM tools outside of
$PATH to find the symbolizer and produce pretty backtraces if they crash.

llvm-svn: 272232
2016-06-09 00:53:21 +00:00
Benjamin Kramer c321e53402 Apply most suggestions of clang-tidy's performance-unnecessary-value-param
Avoids unnecessary copies. All changes audited & pass tests with asan.
No functional change intended.

llvm-svn: 272190
2016-06-08 19:09:22 +00:00
Petr Hosek faef3207de [MC] Rename EmitFill to emitFill
This is to match the overloaded variants as well as the new style.

Differential Revision: http://reviews.llvm.org/D20690

llvm-svn: 271359
2016-06-01 01:59:58 +00:00
Adrian Prantl 9e7e8839b2 dsymutil/modules: Reword the warning for static libraries without module caches
In addition to clarifying the warning message this contains a minor functional
change in that it now warns if the *immediate* parent directory in which the
missing PCM is expected to be isn't found.

This patch also includes a more comprehensive testcase.

rdar://problem/25860711

llvm-svn: 270269
2016-05-20 20:36:06 +00:00
Rafael Espindola 8c34dd8257 Delete Reloc::Default.
Having an enum member named Default is quite confusing: Is it distinct
from the others?

This patch removes that member and instead uses Optional<Reloc> in
places where we have a user input that still hasn't been maped to the
default value, which is now clear has no be one of the remaining 3
options.

llvm-svn: 269988
2016-05-18 22:04:49 +00:00
Rafael Espindola 699281cce7 Don't pass a Reloc::Model to MC.
MC only needs to know if the output is PIC or not. It never has to
decide about creating GOTs and PLTs for example. The only thing that
MC itself uses this information for is expanding "macros" in sparc and
mips. The rest I am pretty sure could be moved to CodeGen.

This is a cleanup and isolates the code from future changes to
Reloc::Model.

llvm-svn: 269909
2016-05-18 11:58:50 +00:00
Adrian Prantl e1bc3e2027 dsymutil: Fix the DWOId mismatch check for cached modules.
In verbose mode, we emit a warning if the DWOId of a skeleton CU
mismatches the DWOId of the referenced module. This patch updates the
cached DWOId after a module has been loaded to the DWOId of the module
on disk (instead of storing the DWOId we expected to load). This
allows us to correctly emit the mismatch warning for all subsequent
object files that want to import the same module. This patch also
ensures both warnings are only emitted in verbose mode.

rdar://problem/26214027

llvm-svn: 269383
2016-05-13 00:17:58 +00:00
Frederic Riss 98f489ce82 [dsymutil] Prevent use-after-free
The BinaryHolder would query the archive member MemoryBuffer name
to check if the current open archive also contains the next requested
objectfile. This comparison was using a StringRef to a temporary
buffer. It only happened with fat archives. This commit adds long-lived
storage along with the MemoryBuffers for the fat archive filename.

The added test would fail during an ASAN build without the fix.

llvm-svn: 268924
2016-05-09 14:44:14 +00:00
Frederic Riss 5af2c005eb [dsymutil] Fix -arch option for thumb variants.
r267249 removed the dual ARM/Thumb interface from MachOObjectFile,
simplifying llvm-dsymutil's code. This unfortunately also regressed
llvm-dsymutil's ability to select thumb slices, because the simplified
code was also dealing with the discrepency between the slice arch
(eg. armv7m) and the triple arch name (eg. thumbv7m).

llvm-svn: 268894
2016-05-09 06:01:12 +00:00
Frederic Riss bd126df21f [dsymutil] Create the temporary files in the system temp directory.
llvm-dsymutil used to create the temporary files in the output directory.
This works fine except when the output directory contains a '%' char, which
is then replaced by llvm::sys::fs::createUniqueFile() generating an invalid
path.
Just use the default temp dir for those files.

llvm-svn: 268304
2016-05-02 21:06:14 +00:00
Kevin Enderby 7bd8d99497 Thread Expected<...> up from libObject’s getType() for symbols to allow llvm-objdump to produce a good error message.
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
2016-05-02 20:28:12 +00:00
Adrian Prantl 2c0b0ab624 dsymutil: Only warn about clang module DWO id mismatches in verbose mode.
Until PR27449 (https://llvm.org/bugs/show_bug.cgi?id=27449) is fixed in
clang this warning is pointless, since ASTFileSignatures will change
randomly when a module is rebuilt.

rdar://problem/25610919

llvm-svn: 267427
2016-04-25 17:04:32 +00:00
Tim Northover 9e8eb418e5 MachO: remove weird ARM/Thumb interface from MachOObjectFile
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
2016-04-22 23:21:13 +00:00
Kevin Enderby 81e8b7d949 Thread Expected<...> up from libObject’s getName() for symbols to allow llvm-objdump to produce a good error message.
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
2016-04-20 21:24:34 +00:00
Kevin Enderby 3fcdf6ae2a Thread Expected<...> up from createMachOObjectFile() to allow llvm-objdump to produce a real error message
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
2016-04-06 22:14:09 +00:00
Kevin Enderby 5afbc1cda7 Fix a crash in running llvm-objdump -t with an invalid Mach-O file already
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
2016-03-23 20:27:00 +00:00
Pete Cooper 64d075ec07 Always cache resolved paths as it even saves on StringMap lookups.
Now that the resolved path cache stores the StringRef's, its
best to just always cache the results, even when realpath isn't
used.  This way we'll still avoid the StringMap hashing and lookup.

This also conveniently reorganises this code in a way I need for
a future patch.

llvm-svn: 263777
2016-03-18 05:04:04 +00:00
Pete Cooper ef4e36ad99 Use StringRef's in resolved path cache to avoid extra internString lookups. NFC.
ResolvedPaths was storing std::string's as a cache. We would then take those strings and look them up in the internString pool to get a unique StringRef for each path.

This patch changes ResolvedPaths to store the StringRef pointing in to the internString pool itself. This way, when getResolvedPath returns a string, we know we have the StringRef we would find in the pool anyway. We can avoid the duplicate memory of the std::string's, and also the time from the lookup.

Unfortunately my profiles show no runtime change here, but it should still save memory allocations which is nice.

Reviewed by Frederic Riss.

Differential Revision: http://reviews.llvm.org/D18259

llvm-svn: 263774
2016-03-18 03:48:09 +00:00
Frederic Riss 1d53658eae [dsymutil] Skip mach-o paired relocations
Noticed while working on scattered relocations.
I do not think these relocs can actually happen in the debug_info section,
but if they happen the code would mishandle them. Explicitely skip them
and warn if we encounter one.

llvm-svn: 259341
2016-02-01 04:43:14 +00:00