The DBI stream contains a list of module descriptors. At the
beginning of each descriptor is a structure representing the first
section contribution in the output file for that module. LLD
currently doesn't fill out this structure at all, but link.exe
does. So as a precursor to emitting this data in LLD, we first
need a way to dump it so that it can be checked.
This patch adds support for the dumping, and verifies via a test
that LLD emits bogus information.
llvm-svn: 330208
These appear in a .debug$P section, which is exactly the same in
format as a .debug$T section. So we shouldn't ignore these when
dumping types.
llvm-svn: 329326
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: JDevlieghere, zturner, echristo, dberris, friss
Reviewed By: echristo
Subscribers: gbedwell, llvm-commits
Differential Revision: https://reviews.llvm.org/D45141
llvm-svn: 328943
When investigating bugs in PDB generation, the first step is
often to do the same link with link.exe and then compare PDBs.
But comparing PDBs is hard because two completely different byte
sequences can both be correct, so it hampers the investigation when
you also have to spend time figuring out not just which bytes are
different, but also if the difference is meaningful.
This patch fixes a couple of cases related to string table emission,
hash table emission, and the order in which we emit strings that
makes more of our bytes the same as the bytes generated by MS PDBs.
Differential Revision: https://reviews.llvm.org/D44810
llvm-svn: 328348
This is still failing on a different bot this time due to some
issue related to hashing absolute paths. Reverting until I can
figure it out.
llvm-svn: 328014
The issue causing this to fail in certain configurations
should be fixed.
It was due to the fact that DIA apparently expects there to be
a null string at ID 1 in the string table. I'm not sure why this
is important but it seems to make a difference, so set it.
llvm-svn: 328002
Natvis is a debug language supported by Visual Studio for
specifying custom visualizers. The /NATVIS option is an
undocumented link.exe flag which will take a .natvis file
and "inject" it into the PDB. This way, you can ship the
debug visualizers for a program along with the PDB, which
is very useful for postmortem debugging.
This is implemented by adding a new "named stream" to the
PDB with a special name of /src/files/<natvis file name>
and simply copying the contents of the xml into this file.
Additionally, we need to emit a single stream named
/src/headerblock which contains a hash table of embedded
files to records describing them.
This patch adds this functionality, including the /NATVIS
option to lld-link.
Differential Revision: https://reviews.llvm.org/D44328
llvm-svn: 327895
This is not a record type that clang currently generates,
but it is a record that is encountered in object files generated
by cl. This record is unusual in that it refers directly to
the string table instead of indirectly to the string table via
the FileChecksums table. Because of this, it was previously
overlooked and we weren't remapping the string indices at all.
This would lead to crashes in MSVC when trying to display a
variable whose debug info involved an S_FILESTATIC.
Original bug report by Alexander Ganea
Differential Revision: https://reviews.llvm.org/D41718
llvm-svn: 321883
We have llvm-readobj for dumping CodeView from object files, and
llvm-pdbutil has always been more focused on PDB. However,
llvm-pdbutil has a lot of useful options for summarizing debug
information in aggregate and presenting high level statistical
views. Furthermore, it's arguably better as a testing tool since
we don't have to write tests to conform to a state-machine like
structure where you match multiple lines in succession, each
depending on a previous match. llvm-pdbutil dumps much more
concisely, so it's possible to use single-line matches in many
cases where as with readobj tests you have to use multi-line
matches with an implicit state machine.
Because of this, I'm adding object file support to llvm-pdbutil.
In fact, this mirrors the cvdump tool from Microsoft, which also
supports both object files and pdb files. In the future we could
perhaps rename this tool llvm-cvutil.
In the meantime, this allows us to deep dive into object files
the same way we already can with PDB files.
llvm-svn: 312358
This adds a new command line option, -udt-stats, which breaks
down the stats of S_UDT records. These are one of the biggest
contributors to the size of /DEBUG:FASTLINK PDBs, so they need
some additional tools to be able to analyze their usage. This
option will dig into each S_UDT record and determine what kind
of record it points to, and then break down the statistics by
the target type. The goal here is to identify how our object
files differ from MSVC object files in S_UDT records, so that
we can output fewer of them and reach size parity.
llvm-svn: 312276
This adds support for dumping a summary of module symbols
and CodeView debug chunks. This option prints a table for
each module of all of the symbols that occurred in the module
and the number of times it occurred and total byte size. Then
at the end it prints the totals for the entire file.
Additionally, this patch adds the -jmc (just my code) option,
which suppresses modules which are from external libraries or
linker imports, so that you can focus only on the object files
and libraries that originate from your own source code.
llvm-svn: 311338
PDBs need to contain 1 module for each object file/compiland,
and a special one synthesized by the linker. This one contains
a symbol record for each output section in the executable with
its address information. This patch adds such symbols to the
linker module. Note that we also are supposed to add an
S_COFFGROUP symbol for what appears to be each input section that
contributes to each output section, but it's not entirely clear
how to generate these yet, so I'm leaving that for a separate
patch.
llvm-svn: 310754
In the refactor to merge the publics and globals stream, a bug
was introduced that wrote the wrong value for one of the fields
of the PublicsStreamHeader. This caused debugging in WinDbg
to break.
We had no way of dumping any of these fields, so in addition to
fixing the bug I've added dumping support for them along with a
test that verifies the correct value is written.
llvm-svn: 310439
The compiler outputs PROC32_ID symbols into the object files
for functions, and these symbols have an embedded type index
which, when copied to the PDB, refer to the IPI stream. However,
the symbols themselves are also converted into regular symbols
(e.g. S_GPROC32_ID -> S_GPROC32), and type indices in the regular
symbol records refer to the TPI stream. So this patch applies
two fixes to function records.
1. It converts ID symbols to the proper non-ID record type.
2. After remapping the type index from the object file's index
space to the PDB file/IPI stream's index space, it then
remaps that index to the TPI stream's index space by.
Besides functions, during the remapping process we were also
discarding symbol record types which we did not recognize.
In particular, we were discarding S_BPREL32 records, which is
what MSVC uses to describe local variables on the stack. So
this patch fixes that as well by copying them to the PDB.
Differential Revision: https://reviews.llvm.org/D36426
llvm-svn: 310394
Image section headers are stored in the DBI stream, but we
had no way to dump them. This patch adds dumping support,
along with some tests that LLD actually dumps them correctly.
Differential Revision: https://reviews.llvm.org/D36332
llvm-svn: 310107
Often something interesting (like a symbol) is in a particular
module, and you don't want to dump symbols from all other 300
modules to see the one you want. This adds a -modi option so that
we only dump the specified module.
llvm-svn: 310000
The banner parameter is supposed to end in a separator, like ": ".
Otherwise, we get ugly errors like:
Error while reading publics streamNative error: blah blah
llvm-svn: 309332
The PDB "symbol stream" actually contains symbol records for the publics
and the globals stream. The globals and publics streams are essentially
hash tables that point into a single stream of records. In order to
match cvdump's behavior, we need to only dump symbol records referenced
from the hash table. This patch implements that, and then implements
global stream dumping, since it's just a subset of public stream
dumping.
Now we shouldn't see S_PROCREF or S_GDATA32 records when dumping
publics, and instead we should see those record in the globals stream.
llvm-svn: 309066
This includes the hash table, the address map, and the thunk table and
section offset table. The last two are only used for incremental
linking, which LLD doesn't support, so they are less interesting. The
hash table is particularly important to get right, since this is the one
of the streams that debuggers use to translate addresses to symbols.
llvm-svn: 308764
Summary:
This removes the CVTypeVisitor updater and verifier classes. They were
made dead by the minimal type dumping refactoring. Replace them with a
single function that takes a type record and produces a hash. Call this
from the minimal type dumper and compare the hash.
I also noticed that the microsoft-pdb reference repository uses a basic
CRC32 for records that aren't special. We already have an implementation
of that CRC ready to use, because it's used in COFF for ICF.
I'll make LLD call this hashing utility in a follow-up change. We might
also consider using this same hash in type stream merging, so that we
don't have to hash our records twice.
Reviewers: inglorion, ruiu
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35515
llvm-svn: 308240
Based strictly on the name, this seems to have something to do
width edit & continue. The goal of this patch has nothing to do
with supporting edit and continue though. msvc link.exe writes
very basic information into this area even when *not* compiling
with support for E&C, and so the goal here is to bring lld-link
to parity. Since we cannot know what assumptions standard tools
make about the content of PDB files, we need to be as close as
possible.
This ECNames data structure is a standard PDB string hash table.
link.exe puts a single string into this hash table, which is the
full path to the PDB file on disk. It then references this string
from the module descriptor for the compiler generated `* Linker *`
module.
With this patch, lld-link will generate the exact same sequence of
bytes as MSVC link for this subsection for a given object file
input (as reported by `llvm-pdbutil bytes -ec`).
llvm-svn: 307356
Type records have a unique type index, but symbol records do
not. Instead, symbol records refer to other symbol records
by referencing their offset in the symbol stream. In a sense
this is the analogue of the TypeIndex, but we are not printing
it in the dumper. Printing it not only gives us more useful
information when manually investigating the contents of a PDB,
but also allows us to write better tests by enabling us to
verify that fields that reference other symbol records do
so correctly.
Differential Revision: https://reviews.llvm.org/D34906
llvm-svn: 306890
Previously we had the -type-index option which would dump the record of
a single, but we had no way to follow the dependency graph backwards and
also dump all dependent types.
Having this option makes test-writing better, because we can limit the
test to only those records that are of importance for the thing we're
trying to test, which allows us to use things like CHECK-NEXT to reduce
fragility.
Differential Revision: https://reviews.llvm.org/D34899
llvm-svn: 306852
This is useful when you want to look at a specific chunk of a
stream or look for discontinuities, and you need to know the
list of blocks occupied by a stream.
llvm-svn: 306150
This idea originally came about when I was doing some deep
investigation of why certain bytes in a PDB that we round-tripped
differed from their original bytes in the source PDB. I found
myself having to hack up the code in many places to dump the
bytes of this substream, or that record. It would be nice if
we could just do this for every possible stream, substream,
debug chunk type, etc.
It doesn't make sense to put this under dump because there's just
so many options that would detract from the more common use case
of just dumping deserialized records. So making a new subcommand
seems like the most logical course of action. In doing so, we
already have two command line options that are suitable for this
new subcommand, so start out by moving them there.
llvm-svn: 306056
Now you run llvm-pdbutil dump <options>. This is a followup
after having renamed the tool, whereas before raw was obviously
just the style of dumping, whereas now "dump" is the action to
perform with the "util".
llvm-svn: 306055
Peter Collingbourne