Commit Graph

22 Commits

Author SHA1 Message Date
Zachary Turner 194be871b9 [LLD/PDB] Emit first section contribution for DBI Module Descriptor.
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
2018-04-20 18:00:46 +00:00
Zachary Turner bee6c22414 [llvm-pdbutil] Dump first section contribution for each module.
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
2018-04-17 20:06:43 +00:00
Peter Collingbourne 8ad3aab4e5 Remove dead code. NFCI.
llvm-svn: 312740
2017-09-07 19:17:30 +00:00
Zachary Turner 946204c83e [PDB] Merge Global and Publics Builders.
The publics stream and globals stream are very similar. They both
contain a list of hash buckets that refer into a single shared stream,
the symbol record stream. Because of the need for each builder to manage
both an independent hash stream as well as a single shared record
stream, making the two builders be independent entities is not the right
design. This patch merges them into a single class, of which only a
single instance is needed to create all 3 streams.  PublicsStreamBuilder
and GlobalsStreamBuilder are now merged into the single GSIStreamBuilder
class, which writes all 3 streams at once.

Note that this patch does not contain any functionality change. So we're
still not yet writing any records to the globals stream. All we're doing
is making it so that when we do start writing records to the globals,
this refactor won't have to be part of that patch.

Differential Revision: https://reviews.llvm.org/D36489

llvm-svn: 310438
2017-08-09 04:23:25 +00:00
Reid Kleckner eacdf04fdd [PDB] Write public symbol records and the publics hash table
Summary:
MSVC link.exe records all external symbol names in the publics stream.
It provides similar functionality to an ELF .symtab.

Reviewers: zturner, ruiu

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35871

llvm-svn: 309303
2017-07-27 18:25:59 +00:00
Zachary Turner 6c4bfba8f3 [PDB] Teach libpdb to write DBI Stream ECNames.
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
2017-07-07 05:04:36 +00:00
Zachary Turner 297b6eb20d [PDB] Don't write uninitialized bytes to a PDB file.
There were certain fields that we didn't know how to write, as
well as various padding bytes that we would ignore.  This leads
to garbage data in the PDB.  While not strictly necessary, we
should initialize these bytes to something meaningful, as it
makes for easier binary comparison between PDBs.

llvm-svn: 305819
2017-06-20 18:50:55 +00:00
Reid Kleckner 44cdb10964 [PDB] Start emitting source file and line information
Summary:
This is a first step towards getting line info to show up in VS and
windbg. So far, only llvm-pdbutil can parse the PDBs that we produce.
cvdump doesn't like something about our file checksum tables. I'll have
to dig into that next.

This patch adds a new DebugSubsectionRecordBuilder which takes bytes
directly from some other producer, such as a linker, and sticks it into
the PDB. Line tables only need to be relocated. No data needs to be
rewritten.

File checksums and string tables, on the other hand, need to be re-done.

Reviewers: zturner, ruiu

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D34257

llvm-svn: 305713
2017-06-19 17:21:45 +00:00
Zachary Turner a8cfc29c9a Resubmit "[codeview] Make obj2yaml/yaml2obj support .debug$S..."
This was originally reverted because of some non-deterministic
failures on certain buildbots.  Luckily ASAN eventually caught
this as a stack-use-after-scope, so the fix is included in
this patch.

llvm-svn: 305393
2017-06-14 15:59:27 +00:00
Zachary Turner 0085dce221 Revert "[codeview] Make obj2yaml/yaml2obj support .debug$S..."
This is causing failures on linux bots with an invalid stream
read.  It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.

llvm-svn: 305371
2017-06-14 06:24:24 +00:00
Zachary Turner a3da4467fa [codeview] Make obj2yaml/yaml2obj support .debug$S/T sections.
This allows us to use yaml2obj and obj2yaml to round-trip CodeView
symbol and type information without having to manually specify the bytes
of the section. This makes for much easier to maintain tests. See the
tests under lld/COFF in this patch for example. Before they just said
SectionData: <blob> whereas now we can use meaningful record
descriptions. Note that it still supports the SectionData yaml field,
which could be useful for initializing a section to invalid bytes for
testing, for example.

Differential Revision: https://reviews.llvm.org/D34127

llvm-svn: 305366
2017-06-14 05:31:00 +00:00
Zachary Turner 264b5d9e88 Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864
2017-06-07 03:48:56 +00:00
Zachary Turner 1bfb9f47af Fix uninitialized read.
llvm-svn: 304846
2017-06-06 23:54:23 +00:00
Zachary Turner 5b74ff33e7 [PDB] Fix use after free.
Previously MappedBlockStream owned its own BumpPtrAllocator that
it would allocate from when a read crossed a block boundary.  This
way it could still return the user a contiguous buffer of the
requested size.  However, It's not uncommon to open a stream, read
some stuff, close it, and then save the information for later.
After all, since the entire file is mapped into memory, the data
should always be available as long as the file is open.

Of course, the exception to this is when the data isn't *in* the
file, but rather in some buffer that we temporarily allocated to
present this contiguous view.  And this buffer would get destroyed
as soon as the strema was closed.

The fix here is to force the user to specify the allocator, this
way it can provide an allocator that has whatever lifetime it
chooses.

Differential Revision: https://reviews.llvm.org/D33858

llvm-svn: 304623
2017-06-03 00:33:35 +00:00
Zachary Turner 92dcdda623 [CodeView] Support CodeView subsections in any order.
Previously we would expect certain subsections to appear
in a certain order because some subsections would reference
other subsections, but in practice we need to support
arbitrary orderings since some object file and PDB file
producers generate them this way.  This also paves the
way for supporting Yaml <-> Object File conversion of
CodeView, since Object Files typically have quite a
large number of subsections in their debug info.

Differential Revision: https://reviews.llvm.org/D33807

llvm-svn: 304588
2017-06-02 19:49:14 +00:00
Zachary Turner ebd3ae8371 [CodeView] Properly align symbol records on read/write.
Object files have symbol records not aligned to any particular
boundary (e.g. 1-byte aligned), while PDB files have symbol
records padded to 4-byte aligned boundaries.  Since they share
the same reading / writing code, we have to provide an option to
specify the alignment and propagate it up to the producer or
consumer who knows what the alignment is supposed to be for the
given container type.

Added a test for this by modifying the existing PDB -> YAML -> PDB
round-tripping code to round trip symbol records as well as types.

Differential Revision: https://reviews.llvm.org/D33785

llvm-svn: 304484
2017-06-01 21:52:41 +00:00
Zachary Turner 8c099fe06e [CodeView] Rename ModuleDebugFragment -> DebugSubsection.
This is more concise, and matches the terminology used in other
parts of the codebase more closely.

llvm-svn: 304218
2017-05-30 16:36:15 +00:00
Zachary Turner 59e83892e0 Fix use after free in BinaryStream library.
This was reported by the ASAN bot, and it turned out to be
a fairly fundamental problem with the design of VarStreamArray
and the way it passes context information to the extractor.

The fix was cumbersome, and I'm not entirely pleased with it,
so I plan to revisit this design in the future when I'm not
pressed to get the bots green again.  For now, this fixes
the issue by storing the context information by value instead
of by reference, and introduces some impossibly-confusing
template magic to make things "work".

llvm-svn: 301999
2017-05-03 05:34:00 +00:00
Zachary Turner edef14510e [PDB/CodeView] Read/write codeview inlinee line information.
Previously we wrote line information and file checksum
information, but we did not write information about inlinee
lines and functions.  This patch adds support for that.

llvm-svn: 301936
2017-05-02 16:56:09 +00:00
Zachary Turner 8a2ebfb1cd [CodeView] Write CodeView line information.
Differential Revision: https://reviews.llvm.org/D32716

llvm-svn: 301882
2017-05-01 23:27:42 +00:00
Zachary Turner 5b6e4e0aed [llvm-pdbdump] Abstract some of the YAML/Raw printing code.
There is a lot of duplicate code for printing line info between
YAML and the raw output printer.  This introduces a base class
that can be shared between the two, and makes some minor
cleanups in the process.

llvm-svn: 301728
2017-04-29 01:13:21 +00:00
Zachary Turner 67c5601404 Rename some PDB classes.
We have a lot of very similarly named classes related to
dealing with module debug info.  This patch has NFC, it just
renames some classes to be more descriptive (albeit slightly
more to type).  The mapping from old to new class names is as
follows:

   Old          |        New
ModInfo         | DbiModuleDescriptor
ModuleSubstream | ModuleDebugFragment
ModStream       | ModuleDebugStream

With the corresponding Builder classes renamed accordingly.

Differential Revision: https://reviews.llvm.org/D32506

llvm-svn: 301555
2017-04-27 16:11:19 +00:00