Commit Graph

342 Commits

Author SHA1 Message Date
Kevin Enderby 2490de06f7 Next set of additional error checks for invalid Mach-O files for the
load commands that use the MachO::sub_framework_command,
MachO::sub_umbrella_command, MachO::sub_library_command
and MachO::sub_client_command types but are not used in llvm
libObject code but used in llvm tool code.

This includes the LC_SUB_FRAMEWORK, LC_SUB_UMBRELLA,
LC_SUB_LIBRARY and LC_SUB_CLIENT load commands.

llvm-svn: 284431
2016-10-17 22:09:25 +00:00
Kevin Enderby 68fffa8a62 Next set of additional error checks for invalid Mach-O files for the
load commands that uses the MachO::linker_option_command
type but not used in llvm libObject code but used in llvm tool code.

This includes just LC_LINKER_OPTION load command.

llvm-svn: 283939
2016-10-11 21:04:39 +00:00
Kevin Enderby f993d6e72c Next set of additional error checks for invalid Mach-O files for the
load commands that uses the MachO::encryption_info_command and
MachO::encryption_info_command types but not used in llvm libObject
code but used in llvm tool code.

This includes just LC_ENCRYPTION_INFO and
LC_ENCRYPTION_INFO_64 load commands.

llvm-svn: 283250
2016-10-04 20:37:43 +00:00
Kevin Enderby 4f229d867b Next set of additional error checks for invalid Mach-O files for the
load command that uses the MachO::entry_point_command type
but not used in llvm libObject code but used in llvm tool code.

This includes just the LC_MAIN load command.

llvm-svn: 282766
2016-09-29 21:07:29 +00:00
Kevin Enderby 245be3ed2a Next set of additional error checks for invalid Mach-O files for the
load command that uses the Mach::source_version_command type
but not used in llvm libObject code but used in llvm tool code.

This includes just the LC_SOURCE_VERSION load command.

llvm-svn: 282736
2016-09-29 17:45:23 +00:00
Kevin Enderby 76966bf066 Next set of additional error checks for invalid Mach-O files for the
load command that uses the Mach::rpath_command type
but not used in llvm libObject code but used in llvm tool code.

This includes just the LC_RPATH load command.

llvm-svn: 282649
2016-09-28 23:16:01 +00:00
Kevin Enderby 32359dbf6b Next set of additional error checks for invalid Mach-O files for the
other load commands that use the Mach::version_min_command type
but not used in llvm libObject code but used in llvm tool code.

This includes LC_VERSION_MIN_MACOSX, LC_VERSION_MIN_IPHONEOS,
LC_VERSION_MIN_TVOS and LC_VERSION_MIN_WATCHOS load commands.

llvm-svn: 282635
2016-09-28 21:20:45 +00:00
Kevin Enderby 3e490ef94e Next set of additional error checks for invalid Mach-O files for the
other load commands that use the MachO::dylinker_command type
but not used in llvm libObject code but used in llvm tool code.

This includes LC_ID_DYLINKER, LC_LOAD_DYLINKER
and LC_DYLD_ENVIRONMENT load commands.

llvm-svn: 282553
2016-09-27 23:24:13 +00:00
Kevin Enderby 90986e6c7c Next set of additional error checks for invalid Mach-O files for the
other load commands that use the Mach::linkedit_data_command type
but not used in llvm libObject code but used in llvm tool code.

This includes LC_FUNCTION_STARTS, LC_SEGMENT_SPLIT_INFO
and LC_DYLIB_CODE_SIGN_DRS load commands.

llvm-svn: 282441
2016-09-26 21:11:03 +00:00
Kevin Enderby e71e13c7d6 Next set of additional error checks for invalid Mach-O files for bad LC_UUID
load commands.  Added a missing check and made the check for more than
one like other other “more than one” checks.  And of course added test cases.

llvm-svn: 282104
2016-09-21 20:03:09 +00:00
Kevin Enderby fc0929adb8 Next set of additional error checks for invalid Mach-O files for bad load commands
that use the Mach::dylib_command type for the load commands that are
currently used in the MachOObjectFile constructor.

This contains the missing checks for LC_ID_DYLIB, LC_ID_DYLIB, etc.
load commands and the fields for the Mach::dylib_command type.

Also checks that only an MH_DYLIB or MH_STUB_DYLIB has an
LC_ID_DYLIB load command (and others filetype don’t) and there
is not more than one of these load commands.

llvm-svn: 282008
2016-09-20 20:14:14 +00:00
Kevin Enderby f76b56cb9c Next set of additional error checks for invalid Mach-O files for bad load commands
that use the Mach::dyld_info_command type for the load commands that are
currently use in the MachOObjectFile constructor.

This contains the missing checks for LC_DYLD_INFO and
LC_DYLD_INFO_ONLY load commands and the fields for the
Mach::dyld_info_command type.

llvm-svn: 281400
2016-09-13 21:42:28 +00:00
Kevin Enderby 9d0c945ad6 Next set of additional error checks for invalid Mach-O files for bad load commands
that use the Mach::linkedit_data_command type for the load commands that are
currently used in the MachOObjectFile constructor.

This contains the missing checks for LC_DATA_IN_CODE and
LC_LINKER_OPTIMIZATION_HINT load commands and the fields for the
Mach::linkedit_data_command type.  Checking for other load commands that
use this type will be added later.

Also fixed a couple of places that was using sizeof(MachOObjectFile::LoadCommandInfo)
that should have been using sizeof(MachO::load_command).

llvm-svn: 280267
2016-08-31 17:57:46 +00:00
Kevin Enderby dcbc504c47 Next set of additional error checks for invalid Mach-O files for bad LC_DYSYMTAB’s.
This contains the missing checks for LC_DYSYMTAB load command fields.

llvm-svn: 280161
2016-08-30 21:28:30 +00:00
Kevin Enderby 0e52c92e22 Next set of additional error checks for invalid Mach-O files for bad LC_SYMTAB’s.
This contains the missing checks for LC_SYMTAB load command fields.

llvm-svn: 279854
2016-08-26 19:34:07 +00:00
NAKAMURA Takumi 9d0b53129c Reformat.
llvm-svn: 279409
2016-08-22 00:58:47 +00:00
NAKAMURA Takumi 59a20649c6 Untabify.
llvm-svn: 279408
2016-08-22 00:58:04 +00:00
Kevin Enderby c614d283b7 Next set of additional error checks for invalid Mach-O files.
This contains the two missing checks for LC_SEGMENT load command fields.
And checks for the Mach-O sections fields that would make them invalid.

With the new checks, some of the existing malformed file checks now trips one
of these instead of the issue it was having before so those tests were adjusted.

llvm-svn: 278557
2016-08-12 20:10:25 +00:00
Kevin Enderby 600fb3f28e Add the first of what will be a long line of additional error checks for invalid Mach-O files.
This is where an LC_SEGMENT load command has a fileoff field that
extends past the end of the file.

Also fix llvm-nm and llvm-size to remove the errorToErrorCode() call so error messages are printed.
And needed to update a few test cases now that they do print the error messages just a
bit differently.

llvm-svn: 277845
2016-08-05 18:19:40 +00:00
Lang Hames 5e51a2e31a [Support] Make ErrorAsOutParameter take an Error* rather than an Error&.
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
2016-07-22 16:11:25 +00:00
Kevin Enderby 1851a827a0 Add checks to the MachOObjectFile() constructor to make sure load commands sizes
are the correct multiple.

llvm-svn: 274798
2016-07-07 22:11:42 +00:00
Kevin Enderby 931cb65df2 Thread Expected<...> up from libObject’s getSymbolAddress() for symbols to allow
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
2016-06-24 18:24:42 +00:00
George Rimar 401e4e570e Recommit r270547 ([llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style.)
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
2016-05-24 12:48:46 +00:00
George Rimar f059dd4f76 Revert r270543 ("Recommit r270540")
Failed build bot in another test.
I am sorry for noise.
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/23679/testReport/junit/LLVM/DebugInfo/llvm_symbolizer_zlib_test/

llvm-svn: 270547
2016-05-24 11:03:10 +00:00
George Rimar e9b2e19109 Recommit r270540
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
2016-05-24 10:46:43 +00:00
George Rimar 6a6185fd78 Revert r270540 "[llvm-dwarfdump] - Teach dwarfdump to decompress debug sections in zlib style."
it broked bot:
http://lab.llvm.org:8011/builders/clang-s390x-linux/builds/5036

llvm-svn: 270541
2016-05-24 09:44:44 +00:00
George Rimar 6bcbf4c572 [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: 270540
2016-05-24 09:28:36 +00:00
Kevin Enderby d4e075be63 Change GenericBinaryError to no longer include a FileName, which is then not
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
2016-05-06 20:16:28 +00:00
Justin Bogner 2a42da996d Object: Fix two -Wpessimizing-move warnings after r268694
llvm-svn: 268697
2016-05-05 23:59:57 +00:00
Kevin Enderby 1e3abcbe76 Fix window bots failures due to r268694 - Cleanup and refactor of malformedError() in lib/Object/MachOObjectFile.cpp .
llvm-svn: 268696
2016-05-05 23:55:27 +00:00
Kevin Enderby 8913496b77 Cleanup and refactor of malformedError() in lib/Object/MachOObjectFile.cpp .
No functional change.

llvm-svn: 268694
2016-05-05 23:41:05 +00:00
Kevin Enderby b34e3a1877 Clean up the specific error message for a malformed Mach-O files with bad segment
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
2016-05-05 17:43:35 +00:00
Kevin Enderby a8e3ab0c56 Produce another specific error message for a malformed Mach-O file when a load
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
2016-05-03 23:13:50 +00:00
Kevin Enderby 368e714907 Produce another specific error message for a malformed Mach-O file when a load
command other than the first one is past the end of the load commands.

This is like the test case in test/Object/macho-invalid.test for
macho64-invalid-incomplete-load-command but it is the second load command
that is past the end of all the load commands instead of the first.

The code in the constructor for MachOObjectFile that loops over the load
commands used getNextLoadCommandInfo() which was not producing
a good error message.  So that was fixed and a test case was added.

llvm-svn: 268403
2016-05-03 17:16:08 +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
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 6e295f2304 Fix a typo in an error message. Caught by Sean Silva!
llvm-svn: 267056
2016-04-21 21:20:40 +00:00
Kevin Enderby 5e55d17ba7 hange the variable name big_size to BigSize. Caught by Rafael Espíndola!
llvm-svn: 267043
2016-04-21 20:29:49 +00:00
Evgeniy Stepanov 2383465e33 Fix compilation error in r266919.
lib/Object/MachOObjectFile.cpp:53:44: error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
  return malformedError(Obj.getFileName(), std::move(Msg.str()), ECOverride);

llvm-svn: 266930
2016-04-20 22:44:40 +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 8702574557 Start to add real error messages for malformed Mach-O files.
And update the existing test cases in test/Object/macho-invalid.test
to use llvm-objdump with the -macho option to produce these
error messages and stop producing the generic "Invalid data
was encountered while parsing the file" message.

Working from the beginning of the file, if the mach header is too large for
the size of the file and then if the load commands that follow extend past
the end of the file these two errors now generate correct error messages.

Both of these have existing test cases in test/Object/macho-invalid.test .

But the first with macho-invalid-header it will never trigger the error message
"mach header extends past the end of the file" using any of the llvm tools as
they all use identify_magic() which rejects files with the correct magic number
that are too small in size.  So I tested this by hacking that code and seeing the
error message down in parseHeader() really does happen.  So in case there
is ever code in llvm that directly calls createMachOObjectFile() this error
message will be correctly produced.

The second error message of "load commands extends past the end of the file"
is triggered by a number of existing tests cases in test/Object/macho-invalid.test .
Also other tests trigger different error messages now like "ilocalsym plus
nlocalsym in LC_DYSYMTAB load command extends past the end of the
symbol table".

There are two existing test cases that still get the "Invalid data was encountered ..."
error messages that I will tackle next.  But they will involve a bit of pluming an
Expect<...> up through the call stack and I want to do those as separate changes.

FYI, for those test cases that were trying to test specific errors that now get
different errors I’ll fix those in follow on changes and create new test cases
for those so they test the error they were meant to test.

llvm-svn: 266248
2016-04-13 21:17:58 +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
David Blaikie b805f73ad1 Remove else after return
llvm-svn: 264599
2016-03-28 17:45:48 +00:00
Lang Hames d1af8fce0f [Support] Switch to RAII helper for error-as-out-parameter idiom.
As discussed on the llvm-commits thread for r264467.

llvm-svn: 264479
2016-03-25 23:54:32 +00:00
Lang Hames ff044b1f69 [Object] Make createMachOObjectFile return Expected<...> rather than
ErrorOr<...>.

llvm-svn: 264473
2016-03-25 23:11:52 +00:00
Lang Hames 8262764869 [Object] Make MachOObjectFile's constructor private, provide a static create
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
2016-03-25 21:59:14 +00:00
Lang Hames 9e964f3728 [Object] Start threading Error through MachOObjectFile construction.
llvm-svn: 264425
2016-03-25 17:25:34 +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
Steven Wu f2fe0141ca Rename embedded bitcode section in MachO
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
2016-02-29 19:40:10 +00:00
Kevin Enderby 1829c686bf Fix the code that leads to the incorrect trigger of the report_fatal_error()
in MachOObjectFile::getSymbolByIndex() when a Mach-O file has
a symbol table load command but the number of symbols are zero.

The code in MachOObjectFile::symbol_begin_impl() should not be
assuming there is a symbol at index 0, in cases there is no symbol
table load command or the count of symbol is zero.  So I also fixed
that.  And needed to fix MachOObjectFile::symbol_end_impl() to
also do the same thing for no symbol table or one with zero entries.

The code in MachOObjectFile::getSymbolByIndex() should trigger
the report_fatal_error() for programmatic errors for any index when
there is no symbol table load command and not return the end iterator.
So also fixed that. Note there is no test case as this is a programmatic
error.

The test case using the file macho-invalid-bad-symbol-index has
a symbol table load command with its number of symbols (nsyms)
is zero. Which was incorrectly testing the bad triggering of the
report_fatal_error() in in MachOObjectFile::getSymbolByIndex().

This test case is an invalid Mach-O file but not for that reason.
It appears this Mach-O file use to have an nsyms value of 11,
and what makes this Mach-O file invalid is the counts and
indexes into the symbol table of the dynamic load command
are now invalid because the number of symbol table entries
(nsyms) is now zero.  Which can be seen with the existing
llvm-obdump:

% llvm-objdump -private-headers macho-invalid-bad-symbol-index
…
Load command 4
     cmd LC_SYMTAB
 cmdsize 24
  symoff 4216
   nsyms 0
  stroff 4392
 strsize 144
Load command 5
            cmd LC_DYSYMTAB
        cmdsize 80
      ilocalsym 0
      nlocalsym 8 (past the end of the symbol table)
     iextdefsym 8 (greater than the number of symbols)
     nextdefsym 2 (past the end of the symbol table)
      iundefsym 10 (greater than the number of symbols)
      nundefsym 1 (past the end of the symbol table)
...

And the native darwin tools generates an error for this file:

% nm macho-invalid-bad-symbol-index
nm: object: macho-invalid-bad-symbol-index truncated or malformed object (ilocalsym plus nlocalsym in LC_DYSYMTAB load command extends past the end of the symbol table)

I added new checks for the indexes and sizes for these in the
constructor of MachOObjectFile.  And added comments for what
would be a proper diagnostic messages.

And changed the test case using macho-invalid-bad-symbol-index
to test for the new error now produced.

Also added a test with a valid Mach-O file with a symbol table
load command where the number of symbols is zero that shows
the report_fatal_error() is not called.

llvm-svn: 258576
2016-01-22 22:49:55 +00:00