The reference implementation uses a case-insensitive string
comparison for strings of equal length. This will cause the
string "tEo" to compare less than "VUo". However we were using
a case sensitive comparison, which would generate the opposite
outcome. Switch to a case insensitive comparison. Also, when
one of the strings contains non-ascii characters, fallback to
a straight memcmp.
The only way to really test this is with a DIA test. Before this
patch, the test will fail (but succeed if link.exe is used instead
of lld-link). After the patch, it succeeds even with lld-link.
llvm-svn: 336464
It seems like the debugger first computes a symbol's bucket,
and then does a binary search of entries in the bucket using the
symbol's name in order to find it. If the bucket entries are not
in sorted order, this obviously won't work. After this patch a
couple of simple test cases show that we generate an exactly
identical GSI hash stream, which is very nice.
llvm-svn: 336405
The code to emit the pieces of the MSF file were actually in
PDBFileBuilder. Move this to MSFBuilder so that we can
theoretically emit an MSF without having a PDB file.
llvm-svn: 335789
Part of the DBI stream is a list of variable length structures
describing each module that contributes to the final executable.
One member of this structure is a section contribution entry that
describes the first section contribution in the output file for
the given module.
We have been leaving this structure unpopulated until now, so with
this patch it is now filled out correctly.
Differential Revision: https://reviews.llvm.org/D45832
llvm-svn: 330457
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
Using Config->is64() will treat ARM64 as Amd64, which is incorrect.
Furthermore, there are more esoteric architectures that could
theoretically be encountered. Just set it directly to the machine
type, which we already know anyway.
llvm-svn: 330157
Most of these are pretty trivial and obvious. Setting the toolchain
version to 14.11 is perhaps a little questionable, but we've been bitten
in the past where one of our version fields sidn't match MSVC's, and I
definitely don't want to go through that diagnosis again as it was
pretty time consuming and hard to track down.
I found all of these by using llvm-pdbutil export to dump the dbi and
pdb streams to a file, then using fc followed by llvm-pdbutil explain to
explain the mismatched bytes.
There are still some more, these are just the low hanging fruit.
Differential Revision: https://reviews.llvm.org/D45276
llvm-svn: 330130
Using this, you can use llvm-pdbutil to export the contents of a
stream to a binary file, then run explain on the binary file so
that it treats the offset as an offset into the stream instead
of an offset into a file. This makes it easy to compare the
contents of the same stream from two different files.
llvm-svn: 329207
The missing definitions are from cvconst.h shipped with DIA SDK.
Correct the url to MSDN for MemoryTypeEnum and set the underlying
type of PDB_StackFrameType and PDB_MemoryType to uint16_t.
llvm-svn: 329104
This command can dump the binary contents of a stream to a file.
This is useful when you want to do side-by-side comparisons of
a specific stream from two PDBs to examine the differences between
them. You can export both of them to a file, then open them up
side by side in a hex editor (for example), so as to eliminate any
differences that might arise from the contents being on different
blocks in the PDB.
In subsequent patches I plan to improve the "explain" subcommand
so that you can explain the contents of a binary file that isn't
necessarily a full PDB, but one of these dumped streams, by telling
the subcommand how to interpret the contents.
llvm-svn: 329002
This will show more detail when using `llvm-pdbutil explain` on an
offset in the DBI or PDB streams. Specifically, it will dig into
individual header fields and substreams to give a more precise
description of what the byte represents.
llvm-svn: 328878
Before this change, using dumpProperties() with PDBSymbolData
would look like this:
get_locationType: 3
1
After this change:
get_locationType: 3
get_value: 1
llvm-svn: 328590
This was reverted several times due to what ultimately turned out
to be incompatibilities in our serialized hash table format.
Several changes went in prior to this to fix those issues since
they were more fundamental and independent of supporting injected
sources, so now that those are fixed this change should hopefully
pass.
llvm-svn: 328363
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
NFC, this just renames some methods to better express what they
do, and also adds a few helper methods to add some symmetry to the
API in a few places (for example there was a getStringFromId but not
a getIdFromString method in the string table).
llvm-svn: 328221
To resolve symbol context at a particular address, we need to
determine the compiland for the address. We are able to determine
the parent compiland of PDBSymbolFunc, PDBSymbolTypeUDT,
PDBSymbolTypeEnum symbols indirectly through line information.
However no such information is availabile for PDBSymbolData,
i.e. variables.
The Section Contribution table from PDBs has information about
each compiland's contribution to sections by address. For example,
a piece of a contribution looks like,
VA RelativeVA Sect No. Offset Length Compiland
14000087B0 000087B0 0001 000077B0 000000BB exe_main.obj
So given an address, it's possible to determine its compiland with
this information.
llvm-svn: 328178
The hash table is a list of buckets, and the *value* stored in
the bucket cannot be 0 since that is reserved. However, the code
here was incorrectly skipping over the 0'th bucket entirely.
The 0'th bucket is perfectly fine, just none of these buckets
can contain the value 0.
As a result, whenever there was a string where hash(S) % Size
was equal to 0, we would write the value in the next bucket
instead. We never caught this in our tests due to *another*
bug, which is that we would iterate the entire list of buckets
looking for the value, only using the hash value as a starting
point. However, the real algorithm stops when it finds 0 in
a bucket since it takes that to mean "the item is not in the
hash table".
The unit test is updated to carefully construct a set of hash
values that will cause one item to hash to 0 mod bucket count,
and the reader is also updated to return an error indicating that
the item is not found when it encounters a 0 bucket.
llvm-svn: 328162
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
Summary:
Redefine PDBSymbolCompiland::getSourceFileName() to return the filename (w/o directory) of the source file that is used to compile the compiland. This is because the result returned previously is ambiguous. It could be the filename, relative path or full path of the source file.
Move the implementation of SymbolFilePDB::GetSourceFileNameForPDBCompiland() into a new method PDBSymbolCompiland::getSourceFileFullPath().
Reviewers: zturner, rnk, llvm-commits
Reviewed By: zturner
Differential Revision: https://reviews.llvm.org/D44458
llvm-svn: 327910
Summary: This commit adds two methods to the PDBSymboFunc class used in parsing symbols. getLineNumbers() is used to determine a Function symbol's declaration and getCompilandId() is used to initialize the SymbolContext field sc.comp_unit.
Reviewers: zturner, rnk, llvm-commits
Reviewed By: zturner
Differential Revision: https://reviews.llvm.org/D44457
llvm-svn: 327909
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
There was some code that tried to calculate the number of 4-byte
words required to hold N bits, but it was instead computing the
number of bytes required to hold N bits. This was leading to
extraneous data being output into the hash table, which would
cause certain operations in DIA (the Microsoft PDB reader) to
fail.
llvm-svn: 327675
It previously only worked when the key and value types were
both 4 byte integers. We now have a use case for a non trivial
value type, so we need to extend it to support arbitrary value
types, which means templatizing it.
llvm-svn: 327647
Summary:
Some PDB symbols do not have a valid VA or RVA but have Addr by Section and Offset. For example, a variable in thread-local storage has the following properties:
get_addressOffset: 0
get_addressSection: 5
get_lexicalParentId: 2
get_name: g_tls
get_symIndexId: 12
get_typeId: 4
get_dataKind: 6
get_symTag: 7
get_locationType: 2
This change provides a new method to locate line numbers by Section and Offset from those symbols.
Reviewers: zturner, rnk, llvm-commits
Subscribers: asmith, JDevlieghere
Differential Revision: https://reviews.llvm.org/D44407
llvm-svn: 327601
Injected sources are basically a way to add actual source file content
to your PDB. Presumably you could use this for shipping your source code
with your debug information, but in practice I can only find this being
used for embedding natvis files inside of PDBs.
In order to effectively test LLVM's natvis file injection, we need a way
to dump the injected sources of a PDB in a way that is authoritative
(i.e. based on Microsoft's understanding of the PDB format, and not
LLVM's). To this end, I've added support for dumping injected sources
via DIA. I made a PDB file that used the /natvis option to generate a
test case.
Differential Revision: https://reviews.llvm.org/D44405
llvm-svn: 327428
Summary: This helps to determine the line number for a PDB type with definition
Reviewers: zturner, llvm-commits, rnk
Reviewed By: zturner
Subscribers: rengolin, JDevlieghere
Differential Revision: https://reviews.llvm.org/D44119
llvm-svn: 326857
For now this is NFC, but this small refactor opens the door to
letting us embed a hash of the PDB in the build id field of the
PDB.
Differential Revision: https://reviews.llvm.org/D43913
llvm-svn: 326453
This was originally reported as a bug with the symptom being "cvdump
crashes when printing an LLD-linked PDB that has an S_FILESTATIC record
in it". After some additional investigation, I determined that this was
a symptom of a larger problem, and in fact the real problem was in the
way we emitted the global PDB string table. As evidence of this, you can
take any lld-generated PDB, run cvdump -stringtable on it, and it would
return no results.
My hypothesis was that cvdump could not *find* the string table to begin
with. Normally it would do this by looking in the "named stream map",
finding the string /names, and using its value as the stream index. If
this lookup fails, then cvdump would fail to load the string table.
To test this hypothesis, I looked at the name stream map generated by a
link.exe PDB, and I emitted exactly those bytes into an LLD-generated
PDB. Suddenly, cvdump could read our string table!
This code has always been hacky and we knew there was something we
didn't understand. After all, there were some comments to the effect of
"we have to emit strings in a specific order, otherwise things don't
work". The key to fixing this was finally understanding this.
The way it works is that it makes use of a generic serializable hash map
that maps integers to other integers. In this case, the "key" is the
offset into a buffer, and the value is the stream number. If you index
into the buffer at the offset specified by a given key, you find the
name. The underlying cause of all these problems is that we were using
the identity function for the hash. i.e. if a string's offset in the
buffer was 12, the hash value was 12. Instead, we need to hash the
string *at that offset*. There is an additional catch, in that we have
to compute the hash as a uint32 and then truncate it to uint16.
Making this work is a little bit annoying, because we use the same hash
table in other places as well, and normally just using the identity
function for the hash function is actually what's desired. I'm not
totally happy with the template goo I came up with, but it works in any
case.
The reason we never found this bug through our own testing is because we
were building a /parallel/ hash table (in the form of an
llvm::StringMap<>) and doing all of our lookups and "real" hash table
work against that. I deleted all of that code and now everything goes
through the real hash table. Then, to test it, I added a unit test which
adds 7 strings and queries the associated values. I test every possible
insertion order permutation of these 7 strings, to verify that it really
does work as expected.
Differential Revision: https://reviews.llvm.org/D43326
llvm-svn: 325386
Summary:
- Fix a bug in PrettyBuiltinDumper that returns "void" as the name for
an unspecified builtin type. Since the unspecified param of a variadic
function is considered a builtin of unspecified type in PDBs, we set
"..." for its name.
- Provide a method to determine if a PDBSymbolFunc is variadic in
PrettyFunctionDumper since PDBSymbolFunc::getArgument() doesn't return the
last unspecified-type param.
- Add a pretty-func-dumper.test to test pretty dumping of variadic
functions.
Reviewers: zturner, llvm-commits
Reviewed By: zturner
Differential Revision: https://reviews.llvm.org/D41801
llvm-svn: 322608
Mandeep Singh Grang