No real functional change with this commit.
The problem with report_fatal_error() is it does not include the tool name
and the file name the for which the error message was generated.
Uses of report_fatal_error() were change to report_error() or error()
to get a better error and to make the code smaller and cleaner.
Also changed things like error(errorToErrorCode(SOrErr.takeError())) to
use report_error() with a file name and the llvm::Error (as well as the
ArchitectureName if available) so the error message is printed.
llvm-svn: 287163
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
To get a good error message for all files that could contain Mach-O
files the code in llvm-objdump needs to use the archive member name
and name of the architecture of a slice of a universal file in those cases
where the error come from a Mach-O file in an archive or a universal file.
Most of this is fixed by moving the call to checkSymbolTable() into
ProcessMachO() and calling it when the operation needs the symbol
table. And then calling the form of report_error() that has the
ArchiveName and ArchitectureName arguments. One other place
needed to call this form of report_error() also with these arguments.
Also changed the code in MachODump.cpp to not use report_fatal_error()
and use report_error() instead to make the code smaller and cleaner. All
cases of this are for errors with the symbol table which should now never
be tripped since checkSymbolTable() should be called first to get a good
error message in these cases.
llvm-svn: 287050
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
Permit specifying the match length (the `-n` or `--bytes` option). The
deprecated `-[length]` form is not supported as an option. This allows the
strings tool to display only the specified length strings rather than the
hardcoded default length of >= 4.
llvm-svn: 286914
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
Summary:
We have always speculatively promoted all renamable local values
(except const non-address taken variables) for both the exporting
and importing module. We would then internalize them back based on
the ThinLink results if they weren't actually exported. This is
inefficient, and results in unnecessary renames. It also meant we
had to check the non-renamability of a value in the summary, which
was already checked during function importing analysis in the ThinLink.
Made renameModuleForThinLTO (which does the promotion/renaming) instead
use the index when exporting, to avoid unnecessary renames/promotions.
For importing modules, we can simply promoted all values as any local
we import by definition is exported and needs promotion.
This required changes to the method used by the FunctionImport pass
(only invoked from 'opt' for testing) and when invoked from llvm-link,
since neither does a ThinLink. We simply conservatively mark all locals
in the index as promoted, which preserves the current aggressive
promotion behavior.
I also needed to change an llvm-lto based test where we had previously
been aggressively promoting values that weren't importable (aliasees),
but now will not promote.
Reviewers: mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D26467
llvm-svn: 286871
This restores the rest of r286297 (part was restored in r286475).
Specifically, it restores the part requiring adding a dependency from
the Analysis to Object library (downstream use changed to correctly
model split BitReader vs BitWriter libraries).
Original description of this part of patch follows:
Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.
This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).
Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.
Fixes PR30610.
llvm-svn: 286844
Also,
Revert "test: remove the archive before modifying it"
Revert "test: explicitly use gnu format"
This reverts commits r286778, r286729 and r286767, as they are randomly failing
on many bots (AArch64, x86_64).
llvm-svn: 286820
`c++filt` when given no arguments runs as a REPL, decoding each line as a
decorated name. Unify the test structure to be more uniform, with the tests for
llvm-cxxfilt living under test/tools/llvm-cxxfilt.
llvm-svn: 286777
Until we have handling for ignoring unloaded sections, simplify the logic to
the point of triviality. This fixes the scanning of archives, particularly when
embedded in archives.
llvm-svn: 286727
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
(1) Add support for function key negotiation.
The previous version of the RPC required both sides to maintain the same
enumeration for functions in the API. This means that any version skew between
the client and server would result in communication failure.
With this version of the patch functions (and serializable types) are defined
with string names, and the derived function signature strings are used to
negotiate the actual function keys (which are used for efficient call
serialization). This allows clients to connect to any server that supports a
superset of the API (based on the function signatures it supports).
(2) Add a callAsync primitive.
The callAsync primitive can be used to install a return value handler that will
run as soon as the RPC function's return value is sent back from the remote.
(3) Launch policies for RPC function handlers.
The new addHandler method, which installs handlers for RPC functions, takes two
arguments: (1) the handler itself, and (2) an optional "launch policy". When the
RPC function is called, the launch policy (if present) is invoked to actually
launch the handler. This allows the handler to be spawned on a background
thread, or added to a work list. If no launch policy is used, the handler is run
on the server thread itself. This should only be used for short-running
handlers, or entirely synchronous RPC APIs.
(4) Zero cost cross type serialization.
You can now define serialization from any type to a different "wire" type. For
example, this allows you to call an RPC function that's defined to take a
std::string while passing a StringRef argument. If a serializer from StringRef
to std::string has been defined for the channel type this will be used to
serialize the argument without having to construct a std::string instance.
This allows buffer reference types to be used as arguments to RPC calls without
requiring a copy of the buffer to be made.
llvm-svn: 286620
In preparation for a follow on patch that improves DWARF parsing speed, clean up DWARFFormValue so that we have can get the fixed byte size of a form value given a DWARFUnit or given the version, address byte size and dwarf32/64.
This patch cleans up code so that everyone is using one of the new DWARFFormValue functions:
static Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, const DWARFUnit *U = nullptr);
static Optional<uint8_t> DWARFFormValue::getFixedByteSize(dwarf::Form Form, uint16_t Version, uint8_t AddrSize, bool Dwarf32);
This patch changes DWARFFormValue::skipValue() to rely on the output of DWARFFormValue::getFixedByteSize(...) instead of duplicating the code in each function. This will reduce the number of changes we need to make to DWARF to fewer places in DWARFFormValue when we add support for new form.
This patch also starts to support DWARF64 so that we can get correct byte sizes for forms that vary according the DWARF 32/64.
To reduce the code duplication a new FormSizeHelper pure virtual class was created that can be created as a FormSizeHelperDWARFUnit when you have a DWARFUnit, or FormSizeHelperManual where you manually specify the DWARF version, address byte size and DWARF32/DWARF64. There is now a single implementation of a function that gets the fixed byte size (instead of two where one took a DWARFUnit and one took the DWARF version, address byte size and DWARFFormat enum) and one function to skip the form values.
https://reviews.llvm.org/D26526
llvm-svn: 286597
Summary:
Split ReaderWriter.h which contains the APIs into both the BitReader and
BitWriter libraries into BitcodeReader.h and BitcodeWriter.h.
This is to address Chandler's concern about sharing the same API header
between multiple libraries (BitReader and BitWriter). That concern is
why we create a single bitcode library in our downstream build of clang,
which led to r286297 being reverted as it added a dependency that
created a cycle only when there is a single bitcode library (not two as
in upstream).
Reviewers: mehdi_amini
Subscribers: dlj, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D26502
llvm-svn: 286566
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
This is a replacement to binutils' string tool. It prints strings found in a
binary (object file, executable, or archive library). It is rather bare and
not functionally equivalent, however, it lays the groundwork necessary for the
strings tool, enabling iterative development of features to reach feature
parity.
llvm-svn: 286556
../tools/llvm-extract/llvm-extract.cpp: In function ‘int main(int, char**)’:
warning: ISO C++ forbids zero-size array ‘argv’ [-Wpedantic]
GCC reference bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61259
llvm-svn: 286396
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
The BitcodeReader no longer produces BitcodeDiagnosticInfo diagnostics.
The only remaining reference was in the gold plugin; the code there has been
dead since we stopped producing InvalidBitcodeSignature error codes in r225562.
While at it remove the InvalidBitcodeSignature error code.
llvm-svn: 286326
Previously support had been added for using CodeViewRecordIO
to read (deserialize) CodeView type records. This patch adds
support for writing those same records. With this patch,
reading and writing of CodeView type records finally uses a single
codepath.
Differential Revision: https://reviews.llvm.org/D26253
llvm-svn: 286304
Summary:
This patch uses the same approach added for inline asm in r285513 to
similarly prevent promotion/renaming of locals used or defined in module
level asm.
All static global values defined in normal IR and used in module level asm
should be included on either the llvm.used or llvm.compiler.used global.
The former were already being flagged as NoRename in the summary, and
I've simply added llvm.compiler.used values to this handling.
Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.
This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).
Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.
Fixes PR30610.
Reviewers: mehdi_amini
Subscribers: johanengelen, krasin, llvm-commits
Differential Revision: https://reviews.llvm.org/D26146
llvm-svn: 286297
Unique ownership is just one possible ownership pattern for the memory buffer
underlying the bitcode reader. In practice, as this patch shows, ownership can
often reside at a higher level. With the upcoming change to allow multiple
modules in a single bitcode file, it will no longer be appropriate for
modules to generally have unique ownership of their memory buffer.
The C API exposes the ownership relation via the LLVMGetBitcodeModuleInContext
and LLVMGetBitcodeModuleInContext2 functions, so we still need some way for
the module to own the memory buffer. This patch does so by adding an owned
memory buffer field to Module, and using it in a few other places where it
is convenient.
Differential Revision: https://reviews.llvm.org/D26384
llvm-svn: 286214
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106630.html
Move block info block state to a new class, BitstreamBlockInfo.
Clients may set the block info for a particular cursor with the
BitstreamCursor::setBlockInfo() method.
At this point BitstreamReader is not much more than a container for an
ArrayRef<uint8_t>, so remove it and replace all uses with direct uses
of memory buffers.
Differential Revision: https://reviews.llvm.org/D26259
llvm-svn: 286207
insufficient to populate the expected struct. Prior to this we already
bailed out of the routine when this situation comes up, so none of this
code had any effect.
If someone wants to bring it back to handle these cases, fixing the
earlier conditions and adding the necessary test cases that actually
exercises it, they can always revert this and go from there.
Both of these were noticed by PVS-Studio due to the identical (dead)
condition.
llvm-svn: 285989
in llvm-objdump for Mach-O files add the printing of the
ARM_THREAD_STATE64 in the same format as
otool-classic(1) on darwin.
To do this the 64-bit ARM general tread state
needed to be defined in include/llvm/Support/MachO.h .
rdar://28985800
llvm-svn: 285967
llvm-readobj.
Another bug caught by PVS-Studio.
It'd be nice to actually have a test for this, but I found it by
inspection from PVS-Studio.
llvm-svn: 285937
Using a pattern similar to that of YamlIO, this allows
us to have a single codepath for translating codeview
records to and from serialized byte streams. The
current patch only hooks this up to the reading of
CodeView type records. A subsequent patch will hook
it up for writing of CodeView type records, and then a
third patch will hook up the reading and writing of
CodeView symbols.
Differential Revision: https://reviews.llvm.org/D26040
llvm-svn: 285836
As proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-October/106595.html
This change also fixes an API oddity where BitstreamCursor::Read() would
return zero for the first read past the end of the bitstream, but would
report_fatal_error for subsequent reads. Now we always report_fatal_error
for all reads past the end. Updated clients to check for the end of the
bitstream before reading from it.
I also needed to add padding to the invalid bitcode tests in
test/Bitcode/. This is because the streaming interface was not checking that
the file size is a multiple of 4.
Differential Revision: https://reviews.llvm.org/D26219
llvm-svn: 285773
Summary:
This fixes a few things that used to work with a Makefile build, but were broken in cmake.
1. Treat MINGW like a Linux system.
2. The shlib should never contain other shared libraries.
Patch By: Valentin Churavy
Reviewers: axw, beanz
Subscribers: modocache, beanz, mgorny
Differential Revision: https://reviews.llvm.org/D25865
llvm-svn: 285737
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
Summary:
There is no point to importing at -O0, since we won't inline. We should
also disable other cross-module optimizations.
(Plan to backport this fix to the 3.9 branch to fix PR30774)
Reviewers: pcc
Subscribers: johanengelen, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25918
llvm-svn: 285648
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
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
Most of the version of report_error were quoting the filename and
printing a colon between the file name and the error message, but this
one wasn't doing either of those. Fix the output to be more
consistent.
llvm-svn: 285252
Usage:
llvm-xray extract <object file> [-o <filename or '-'>]
The tool gets the XRay instrumentation map from an object file and turns
it into YAML. We first support ELF64 sleds on x86_64 binaries, with
provision for supporting other supported platforms and formats later.
This is the first of a many-part change to fully implement the
`llvm-xray` tool.
We also define a subcommand registration and dispatch mechanism to be
used by other further subcommand implementations for llvm-xray.
Diffusion Revision: https://reviews.llvm.org/D21987
llvm-svn: 285165
Usage:
llvm-xray extract <object file> [-o <filename or '-'>]
The tool gets the XRay instrumentation map from an object file and turns
it into YAML. We first support ELF64 sleds on x86_64 binaries, with
provision for supporting other supported platforms and formats later.
This is the first of a many-part change to fully implement the
`llvm-xray` tool.
We also define a subcommand registration and dispatch mechanism to be
used by other further subcommand implementations for llvm-xray.
llvm-svn: 285155
This adds a new function to DebugInfo.cpp that takes an llvm::Module
as input and removes all debug info metadata that is not directly
needed for line tables, thus effectively stripping all type and
variable information from the module.
The primary motivation for this feature was the bitcode work flow
(cf. http://lists.llvm.org/pipermail/llvm-dev/2016-June/100643.html
for more background). This is not wired up yet, but will be in
subsequent patches. For testing, the new functionality is exposed to
opt with a -strip-nonlinetable-debuginfo option.
The secondary use-case (and one that works right now!) is as a
reduction pass in bugpoint. I added two new bugpoint options
(-disable-strip-debuginfo and -disable-strip-debug-types) to control
the new features. By default it will first attempt to remove all debug
information, then only the type info, and then proceed to hack at any
remaining MDNodes.
Thanks to Adrian Prantl for stewarding this patch!
llvm-svn: 285094
In an IR symbol table I would expect the comdats to be represented as:
- A table of strings, one for each comdat name.
- Each symbol has an optional index into that table.
The natural api for accessing that would be
InputFile:
ArrayRef<StringRef> getComdatTable() const;
Symbol:
int getComdatIndex() const;
This patch implements an API as close to that as possible. The
implementation on top of the current IRObjectFile is a bit hackish,
but should map just fine over a symbol table and is very convenient to
use.
llvm-svn: 285061
When we load coverage data from multiple objects, we don't have a way to
attribute a source object to a function record. Printing out the object
filename next to the source filename is already not very useful: soon,
it'll actually become misleading. Stop printing out the filename now.
llvm-svn: 285043
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
iterating over an archive with object and non-object members that
would cause an Abort because to was not calling consumeError()
when the code was wanting to ignore a non-object file.
Found by Justin Bogner!
llvm-svn: 284867
Summary: This adds support for dumping the globals stream from PDB files using llvm-pdbdump, similar to the support we have for the publics stream.
Reviewers: ruiu, zturner
Subscribers: beanz, mgorny, modocache
Differential Revision: https://reviews.llvm.org/D25801
llvm-svn: 284861
the ARM_THREAD_STATE in the same format as
otool-classic(1) on darwin.
Also remove an extra space in printing the initprot to make
the output match otool-classic(1) on darwin.
rdar://28851457
llvm-svn: 284852
This was all using ArrayRef<>s before which presents a problem
when you want to serialize to or deserialize from an actual
PDB stream. An ArrayRef<> is really just a special case of
what can be handled with StreamInterface though (e.g. by using
a ByteStream), so changing this to use StreamInterface allows
us to plug in a PDB stream and get all the record serialization
and deserialization for free on a MappedBlockStream.
Subsequent patches will try to remove TypeTableBuilder and
TypeRecordBuilder in favor of class that operate on
Streams as well, which should allow us to completely merge
the reading and writing codepaths for both types and symbols.
Differential Revision: https://reviews.llvm.org/D25831
llvm-svn: 284762
Profile runtime can generate an empty raw profile (when there is no function in
the shared library). This empty profile is treated as a text format profile. A
test format profile without the flag of "#IR" is thought to be a clang
generated profile. So in llvm profile merging, we will get a bogus warning of
"Merge IR generated profile with Clang generated profile."
The fix here is to skip the empty profile (when the buffer size is 0) for
profile merge.
Reviewers: vsk, davidxl
Differential Revision: http://reviews.llvm.org/D25687
llvm-svn: 284659
Initializing a ThreadPool with ThreadCount = 1 spawns a thread even
though we don't need to. This is at least slower than it needs to be,
and at worst may somehow be exacerbating PR30735 (llvm-cov times out
on ARM bots).
As a follow-up, I'll try to add logic to llvm::ThreadPool to avoid
spawning a thread when ThreadCount = 1.
llvm-svn: 284621
Summary:
Changes default backend parallelism from thread::hardware_concurrency to
the new llvm::heavyweight_hardware_concurrency, which for X86 Linux
defaults to the number of physical cores (and will fall back to
thread::hardware_concurrency otherwise). This avoid oversubscribing
the physical cores using hyperthreading.
Reviewers: mehdi_amini, pcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25775
llvm-svn: 284618
This is just a quick utility handy for getting rough summaries of types
in a given object or dwo file. I've been using it to investigate the
amount of type info redundancy across a project build, for example.
llvm-svn: 284537
