Many places pass around a DWARFDebugInfoEntryMinimal and a DWARFUnit. It is easy to get things wrong by using the wrong DWARFUnit with a DWARFDebugInfoEntryMinimal. This patch creates a DWARFDie class that contains the DWARFUnit and DWARFDebugInfoEntryMinimal objects so that they can't get out of sync. All attribute extraction has been moved out of DWARFDebugInfoEntryMinimal and into DWARFDie. DWARFDebugInfoEntryMinimal was also renamed to DWARFDebugInfoEntry.
DWARFDie objects are temporary objects that are used by clients and contain 2 pointers that you always need to have anyway. Keeping them grouped will avoid errors and simplify many of the attribute extracting APIs by not having to pass in a DWARFUnit.
Differential Revision: https://reviews.llvm.org/D27634
llvm-svn: 289565
The only tests we have for the DWARF parser are the tests that use llvm-dwarfdump and expect output from textual dumps.
More DWARF parser modification are coming in the next few weeks and I wanted to add tests that can verify that we can encode and decode all form types, as well as test some other basic DWARF APIs where we ask DIE objects for their children and siblings.
DwarfGenerator.cpp was added in the lib/CodeGen directory. This file contains the code necessary to easily create DWARF for tests:
dwarfgen::Generator DG;
Triple Triple("x86_64--");
bool success = DG.init(Triple, Version);
if (!success)
return;
dwarfgen::CompileUnit &CU = DG.addCompileUnit();
dwarfgen::DIE CUDie = CU.getUnitDIE();
CUDie.addAttribute(DW_AT_name, DW_FORM_strp, "/tmp/main.c");
CUDie.addAttribute(DW_AT_language, DW_FORM_data2, DW_LANG_C);
dwarfgen::DIE SubprogramDie = CUDie.addChild(DW_TAG_subprogram);
SubprogramDie.addAttribute(DW_AT_name, DW_FORM_strp, "main");
SubprogramDie.addAttribute(DW_AT_low_pc, DW_FORM_addr, 0x1000U);
SubprogramDie.addAttribute(DW_AT_high_pc, DW_FORM_addr, 0x2000U);
dwarfgen::DIE IntDie = CUDie.addChild(DW_TAG_base_type);
IntDie.addAttribute(DW_AT_name, DW_FORM_strp, "int");
IntDie.addAttribute(DW_AT_encoding, DW_FORM_data1, DW_ATE_signed);
IntDie.addAttribute(DW_AT_byte_size, DW_FORM_data1, 4);
dwarfgen::DIE ArgcDie = SubprogramDie.addChild(DW_TAG_formal_parameter);
ArgcDie.addAttribute(DW_AT_name, DW_FORM_strp, "argc");
// ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref4, IntDie);
ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref_addr, IntDie);
StringRef FileBytes = DG.generate();
MemoryBufferRef FileBuffer(FileBytes, "dwarf");
auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
EXPECT_TRUE((bool)Obj);
DWARFContextInMemory DwarfContext(*Obj.get());
This code is backed by the AsmPrinter code that emits DWARF for the actual compiler.
While adding unit tests it was discovered that DIEValue that used DIEEntry as their values had bugs where DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref8, and DW_FORM_ref_udata forms were not supported. These are all now supported. Added support for DW_FORM_string so we can emit inlined C strings.
Centralized the code to unique abbreviations into a new DIEAbbrevSet class and made both the dwarfgen::Generator and the llvm::DwarfFile classes use the new class.
Fixed comments in the llvm::DIE class so that the Offset is known to be the compile/type unit offset.
DIEInteger now supports more DW_FORM values.
There are also unit tests that cover:
Encoding and decoding all form types and values
Encoding and decoding all reference types (DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8, DW_FORM_ref_udata, DW_FORM_ref_addr) including cross compile unit references with that go forward one compile unit and backward on compile unit.
Differential Revision: https://reviews.llvm.org/D27326
llvm-svn: 289010
Summary: The code we use to read PDBs assumed that streams we ask it to read exist, and would read memory outside a vector and crash if this wasn't the case. This would, for example, cause llvm-pdbdump to crash on PDBs generated by lld. This patch handles such cases more gracefully: the PDB reading code in LLVM now reports errors when asked to get a stream that is not present, and llvm-pdbdump will report missing streams and continue processing streams that are present.
Reviewers: ruiu, zturner
Subscribers: thakis, amccarth
Differential Revision: https://reviews.llvm.org/D27325
llvm-svn: 288722
PDBFileBuilder supports two different ways to create files.
One is PDBFileBuilder::commit. That function takes a filename
and write a result to the file. The other is PDBFileBuilder::build.
That returns a new PDBFile object.
This patch removes the latter because no one is using it and
in a real life situation we are very unlikely to need it.
Even if you need it, it'd be easy to write a new PDB to a memory
buffer and read it back.
Removing PDBFileBuilder::build enables us to remove other classes
build transitively.
Differential Revision: https://reviews.llvm.org/D26987
llvm-svn: 287697
This is required by DbiStream, but DbiStreamBuilder didn't align
these substreams, so the output of DbiSTreamBuilder couldn't be
read by DbiStream.
Test will be added to LLD.
llvm-svn: 287067
These numbers are intended to be capped at 65535, but
`std::max<uint16_t>(UINT16_MAX, N)` always returns N for any N because
the expression is the same as `std::max((uint16_t)UINT16_MAX, (uint16_t)N)`.
llvm-svn: 287060
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
This patch defines a new function to add a SectionContribs stream
to a PDB file. Unlike SectionMap, SectionContribs contains a list
of input sections as opposed to output sections.
Note that this patch needs improving because currently we do not
set Module field in SectionContribs entries. In a follow-up patch,
I'll add Modules and then fix it after that.
Differential Revision: https://reviews.llvm.org/D26210
llvm-svn: 286677
https://reviews.llvm.org/D26526
- Fixed DW_FORM_strp to be correctly sized and extracted for DWARF64
- Added some missing strp variants as well
- Fixed comment typo
llvm-svn: 286603
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
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
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
This change enables LLD to construct a Section Map stream in a PDB file.
I do not understand all these fields in the Section Map yet, but it seems
like a copy of a COFF section header in another format.
With this patch, DbiStreamBuilder can emit a Section Map which
llvm-pdbdump can dump.
Differential Revision: https://reviews.llvm.org/D26112
llvm-svn: 285606
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
Summary:
Fixes PR28281.
MSVC lists indirect virtual base classes in the field list of a class,
using LF_IVBCLASS records. This change makes LLVM emit such records
when processing DW_TAG_inheritance tags with the DIFlagVirtual and
(newly introduced) DIFlagIndirect tags.
Reviewers: rnk, ruiu, zturner
Differential Revision: https://reviews.llvm.org/D25578
llvm-svn: 285130
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
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
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
In the MS ABI, the frontend is supposed to MD5 such pathologically long
names. LLVM should still defend itself from long names, though.
Fixes part of PR29098.
llvm-svn: 284136
The previous commit was failing because we filled empty slots of
the debug stream index with kInvalidStreamIndex. It should've been 0.
llvm-svn: 283925
Previously, there is no way to create a stream other than pre-defined
special stream such as DBI or IPI. This patch adds a new method,
addDbgStream, to add a debug stream to a PDB file.
Differential Revision: https://reviews.llvm.org/D25356
llvm-svn: 283823
This is the first step towards round-tripping symbol information,
and thusly being able to write symbol information to a PDB.
This patch writes the symbol information for each compiland to
the Yaml when running in pdb2yaml mode. There's still some loose
ends, such as what to do about relocations (necessary in order to
print linkage names), how to print enums with friendly names, and
how to give the dumper access to the StringTable, but this is a
good first start.
llvm-svn: 283641
Type visitor code had already been refactored previously to
decouple the visitor and the visitor callback interface. This
was necessary for having the flexibility to visit in different
ways (for example, dumping to yaml, reading from yaml, dumping
to ScopedPrinter, etc).
This patch merely implements the same visitation pattern for
symbol records that has already been implemented for type records.
llvm-svn: 283609
When we create a PDB file using PDBFileBuilder, the information
in the superblock, such as the size of the resulting file, is not
available.
Previously, PDBFileBuilder::initialize took a superblock assuming
that all the members of the struct are correct. That is useful when
you want to restore the exact information from a YAML file, but
that's probably the only use case in which that is useful.
When we are creating a PDB file on the fly, we have to backfill the
members.
This patch redefines PDBFileBuilder::initialize to take only a
block size. Now all the other members are left as default values,
so that they'll be updated when commit() is called.
Differential Revision: https://reviews.llvm.org/D25108
llvm-svn: 282944
WritableStream needs the exact file size to open a file, but
until we fix the final layout of a PDB file, we don't know the
size of the file.
This patch changes the parameter type of PDBFileBuilder::commit
to solve that chiecken-and-egg problem. Now the function opens
a file after fixing the layout, so it can create a file with the
exact size.
Differential Revision: https://reviews.llvm.org/D25107
llvm-svn: 282940
The IPI stream is structurally identical to the TPI stream, but it
contains different record types. So we just re-use the TPI writing
code.
llvm-svn: 281638
We were inadvertently adding the size of the hash value stream to
the size of the TPI stream, even though the hash value stream is
an entirely separate stream.
llvm-svn: 281636
The `CVType` had two redundant fields which were confusing and
error-prone to fill out. By treating member records as a distinct
type from leaf records, we are able to simplify this quite a bit.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D24432
llvm-svn: 281556
This completes being able to write all the interesting
values of a PDB TPI stream.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D24370
llvm-svn: 281555
We have various command line options that print the type of a
stream, the size of a stream, etc but nowhere that it can all be
viewed together.
Since a previous patch introduced the ability to dump the bytes
of a stream, this seems like a good place to present a full view
of the stream's properties including its size, what kind of data
it represents, and the blocks it occupies. So I added the
ability to print that information to the -stream-data command
line option.
llvm-svn: 281077
This simplifies a lot of code, and will actually be necessary for
an upcoming patch to serialize TPI record hash values.
The idea before was that visitors should be examining records, not
modifying them. But this is no longer true with a visitor that
constructs a CVRecord from Yaml. To handle this until now, we
were doing some fixups on CVRecord objects at a higher level, but
the code is really awkward, and it makes sense to just have the
visitor write the bytes into the CVRecord. In doing so I uncovered
a few bugs related to `Data` and `RawData` and fixed those.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D24362
llvm-svn: 281067
This writes the full sequence of type records described in
Yaml to the TPI stream of the PDB file.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D24316
llvm-svn: 281063
Previously we were splitting our records at 0xFFFF bytes, which the
Microsoft tools don't like.
Should fix failure on the new Windows self-host buildbot.
This length appears in microsoft-pdb/PDB/dbi/dbiimpl.h
llvm-svn: 280522
With that change, images built with 'lld-link /debug' always have a
debug directory. If no PDB filename was passed on the command line, then
the filename in the executable is empty.
PDB information would never work anyway if the PDB file name is empty,
so go ahead and try DWARF in that case.
llvm-svn: 280410
Previously we were assuming that any visitation of types would
necessarily be against a type we had binary data for. Reasonable
assumption when were just reading PDBs and dumping them, but once
we start writing PDBs from Yaml this breaks down, because we have
no binary data yet, only Yaml, and from that we need to read the
record kind and perform the switch based on that.
So this patch does that. Instead of having the visitor switch
on the kind that is already in the CVType record, we change the
visitTypeBegin() method to return the Kind, and switch on the
returned value. This way, the default implementation can still
return the value from the CVType, but the implementation which
visits Yaml records and serializes binary PDB type records can
use the field in the Yaml as the source of the switch.
llvm-svn: 280307
We were kind of hacking this together before by embedding the
ability to forward requests into the TypeDeserializer. When
we want to start adding more different kinds of visitor callback
interfaces though, this doesn't scale well and is very inflexible.
So introduce the notion of a pipeline, which itself implements
the TypeVisitorCallbacks interface, but which contains an internal
list of other callbacks to invoke in sequence.
Also update the existing uses of CVTypeVisitor to use this new
pipeline class for deserializing records before visiting them
with another visitor.
llvm-svn: 280293
The shape of the vtable is passed down as the size of the
__vtbl_ptr_type. This special pointer type appears both as the pointee
type of the vptr type, and by itself in every dynamic class. For classes
with multiple vtables, only the shape of the primary vftable is
included, as the shape of all secondary vftables will be the same as in
the base class.
Fixes PR28150
llvm-svn: 280254
The original patch was breaking some buildbots due to an
incorrect ordering of function definitions which caused some
compilers to recognize a definition but others to not.
llvm-svn: 279089
The DebugDirectory contains a pointer to the CodeView info structure which is a
derivative of the OMF debug directory. The structure has evolved a bit over
time, and PDB 2.0 used a slightly different definition from PDB 7.0. Both of
these are specific to CodeView and not COFF. Reflect this by moving the
structure definitions into the DebugInfo/CodeView headers. Define a generic
DebugInfo union type that can be used to pass around a reference to the
DebugInfo irrespective of the versioning. NFC.
llvm-svn: 278075
Until now, our use case for the visitor has been to take a stream of bytes
representing a type stream, deserialize the records in sequence, and do
something with them, where "something" is determined by how the user
implements a particular set of callbacks on an abstract class.
For actually writing PDBs, however, we want to do the reverse. We have
some kind of description of the list of records in their in-memory format,
and we want to process each one. Perhaps by serializing them to a byte
stream, or perhaps by converting them from one description format (Yaml)
to another (in-memory representation).
This was difficult in the current model because deserialization and
invoking the callbacks were tightly coupled.
With this patch we change this so that TypeDeserializer is itself an
implementation of the particular set of callbacks. This decouples
deserialization from the iteration over a list of records and invocation
of the callbacks. TypeDeserializer is initialized with another
implementation of the callback interface, so that upon deserialization it
can pass the deserialized record through to the next set of callbacks. In
a sense this is like an implementation of the Decorator design pattern,
where the Deserializer is a decorator.
This will be useful for writing Pdbs from yaml, where we have a
description of the type records in Yaml format. In this case, the visitor
implementation would have each visitation callback method implemented in
such a way as to extract the proper set of fields from the Yaml, and it
could maintain state that builds up a list of these records. Finally at
the end we can pass this information through to another set of callbacks
which serializes them into a byte stream.
Reviewed By: majnemer, ruiu, rnk
Differential Revision: https://reviews.llvm.org/D23177
llvm-svn: 277871
pdbdump calls DbiStreamBuilder::commit through PDBFileBuilder::commit
without calling DbiStreamBuilder::finalize. Because `finalize` initializes
`Header` member, `Header` remained nullptr which caused a crash bug.
Differential Revision: https://reviews.llvm.org/D23143
llvm-svn: 277681
MappedBlockSTream can work with any sequence of block data where
the ordering is specified by a list of block numbers. So rather
than manually stitch them together in the case of the FPM, reuse
this functionality so that we can treat the FPM as if it were
contiguous.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D23066
llvm-svn: 277609
BitVector::extend initializes extended bits as true by default.
That is not desirable because new pages should be initially free.
Differential Revision: https://reviews.llvm.org/D23048
llvm-svn: 277529
The FPM is split at regular intervals across the MSF file, as the MS code
suggests. It turns out that the value of the interval is precisely the
block size. If the block size is 4096, then there are two Fpm pages every
4096 blocks.
So here we teach the PDBFile class to parse a split FPM, and also add more
options when dumping the FPM to display some additional information such
as orphaned pages (pages which the FPM says are allocated, but which
nothing appears to use), use after free pages (pages which the FPM says
are not allocated, but which are referenced by a stream), and multiple use
pages (pages which the FPM says are allocated but are used more than
once).
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D23022
llvm-svn: 277388
Previously this change was submitted from a Windows machine, so
changes made to the case of filenames and directory names did
not survive the commit, and as a result the CMake source file
names and the on-disk file names did not match on case-sensitive
file systems.
I'm resubmitting this patch from a Linux system, which hopefully
allows the case changes to make it through unfettered.
llvm-svn: 277213
In a previous patch, it was suggested to use all caps instead of
rolling caps for initialisms, so this patch changes everything
to do this.
llvm-svn: 277190
This was a pure virtual base class whose purpose was to abstract
away the notion of how you retrieve the layout of a discontiguous
stream of blocks in an Msf file. This led to too many layers of
abstraction making it difficult to figure out what was going on
and extend things. Ultimately, a stream's layout is decided by
its length and the array of block numbers that it lives on. So
rather than have an abstract base class which can return this in
any number of ways, it's more straightforward to simply store them
as fields of a trivial struct, and also to give a more appropriate
name.
This patch does that. It renames IMsfStreamData to MsfStreamLayout,
and deletes the 2 concrete implementations, DirectoryStreamData
and IndexedStreamData. MsfStreamLayout is a trivial struct
with the necessary data.
llvm-svn: 277018
Previously it was storing all the fields of an msf::Layout as
separate members. This is a trivial cleanup to make it store
an msf::Layout directly. This makes the code more readable
since it becomes clear which fields of PDBFile are actually the
msf specific layout information in a sea of other bookkeeping
fields.
llvm-svn: 276460
This makes it easier to have the writable and readable PDB
interfaces share code since the read/write and write-only
interfaces now share a single allocator, you don't have to worry
about a builder building a read only interface and then having
the read-only interface's data become corrupt when the builder
goes out of scope. Now the allocator is specified explicitly
to all constructors, so all interfaces can share a single allocator
that is scoped appropriately.
llvm-svn: 276459
This provides a better layering of responsibilities among different
aspects of PDB writing code. Some of the MSF related code was
contained in CodeView, and some was in PDB prior to this. Further,
we were often saying PDB when we meant MSF, and the two are
actually independent of each other since in theory you can have
other types of data besides PDB data in an MSF. So, this patch
separates the MSF specific code into its own library, with no
dependencies on anything else, and DebugInfoCodeView and
DebugInfoPDB take dependencies on DebugInfoMsf.
llvm-svn: 276458
This facilitates code reuse between the builder classes and the
"frozen" read only versions of the classes used for parsing
existing PDB files.
llvm-svn: 276427
This implements support for writing compiland and compiland source
file info to a binary PDB. This is tested by adding support for
dumping these fields from an existing PDB to yaml, reading them
back in, and dumping them again and verifying the values are as
expected.
llvm-svn: 276426
This change adds a hasFileAtIndex method. getChildDeclContext can first call this method, and if it returns true it knows it can then lookup the resolved path cache for the given file index. If we hit that cache then we don't even have to call getFileNameByIndex.
Running dsymutil against the swift executable built from github gives a 20% performance improvement without any change in the binary.
Differential Revision: https://reviews.llvm.org/D22655
Reviewed by friss.
llvm-svn: 276380
Block 1 and 2 of an MSF file are bit vectors that represent the
list of blocks allocated and free in the file. We had been using
these blocks to write stream data and other data, so we mark them
as the free page map now. We don't yet serialize these pages to
the disk, but at least we make a note of what it is, and avoid
writing random data to them.
Doing this also necessitated cleaning up some of the tests to be
more general and hardcode fewer values, which is nice.
llvm-svn: 275629
Previously we would read a PDB, then write some of it back out,
but write the directory, super block, and other pertinent metadata
back out unchanged. This generates incorrect PDBs since the amount
of data written was not always the same as the amount of data read.
This patch changes things to use the newly introduced `MsfBuilder`
class to write out a correct and accurate set of Msf metadata for
the data *actually* written, which opens up the door for adding and
removing type records, symbol records, and other types of data to
an existing PDB.
llvm-svn: 275627
Greg Clayton