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
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
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
In order to efficiently write PDBs, we need to be able to make a
StreamWriter class similar to a StreamReader, which can transparently deal
with writing to discontiguous streams, and we need to use this for all
writing, similar to how we use StreamReader for all reading.
Most discontiguous streams are the typical numbered streams that appear in
a PDB file and are described by the directory, but the exception to this,
that until now has been parsed by hand, is the directory itself.
MappedBlockStream works by querying the directory to find out which blocks
a stream occupies and various other things, so naturally the same logic
could not possibly work to describe the blocks that the directory itself
resided on.
To solve this, I've introduced an abstraction IPDBStreamData, which allows
the client to query for the list of blocks occupied by the stream, as well
as the stream length. I provide two implementations of this: one which
queries the directory (for indexed streams), and one which queries the
super block (for the directory stream).
This has the side benefit of vastly simplifying the code to parse the
directory. Whereas before a mini state machine was rolled by hand, now we
simply use FixedStreamArray to read out the stream sizes, then build a
vector of FixedStreamArrays for the stream map, all in just a few lines of
code.
Reviewed By: ruiu
Differential Revision: http://reviews.llvm.org/D21046
llvm-svn: 271982
PDBs can be extremely large. We're already mapping the entire
PDB into the process's address space, but to make matters worse
the blocks of the PDB are not arranged contiguously. So, when
we have something like an array or a string embedded into the
stream, we have to make a copy. Since it's convenient to use
traditional data structures to iterate and manipulate these
records, we need the memory to be contiguous.
As a result of this, we were using roughly twice as much memory
as the file size of the PDB, because every stream was copied
out and re-stitched together contiguously.
This patch addresses this by improving the MappedBlockStream
to allocate from a BumpPtrAllocator only when a read requires
a discontiguous read. Furthermore, it introduces some data
structures backed by a stream which can iterate over both
fixed and variable length records of a PDB. Since everything
is backed by a stream and not a buffer, we can read almost
everything from the PDB with zero copies.
Differential Revision: http://reviews.llvm.org/D20654
Reviewed By: ruiu
llvm-svn: 270951
We have need to reuse this functionality, including making
additional generic stream types that are smarter about how and
when they copy memory versus referencing the original memory.
So all of these structures belong in the common library
rather than being pdb specific.
llvm-svn: 270751
Zachary Turner