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
This will be useful once we start adding the ability to dump type
records and symbol records, since it will allow us to generate
mergeable information instead of information that specifies an
entire file.
llvm-svn: 275109
There is no polymorphism here, and StreamRef already contains a
StreamInterface pointer. Dropping the base class makes StreamRef more
transparent to the compiler, for example it can find unused variables.
llvm-svn: 275013
Somehow all the functionality to write PDB files got removed,
probably accidentally when uploading the patch perhaps the wrong
one got uploaded. This re-adds all the code, as well as the
corresponding test.
llvm-svn: 274248
This allows better catching of compiler errors since we can use
the override keyword to verify that methods are actually
overridden.
Also in this patch I've changed from storing a boolean Error
code everywhere to returning an llvm::Error, to propagate richer
error information up the call stack.
Reviewed By: ruiu, rnk
Differential Revision: http://reviews.llvm.org/D21410
llvm-svn: 272926
This reverts commit 879139e1c6577b09df52de56a6bab856a19ed185.
This was committed accidentally when I blindly typed git svn
dcommit instead of the command to generate a patch.
llvm-svn: 272693
This is the next step towards being able to write PDBs.
MemoryBuffer is immutable, and StreamInterface is our replacement
which can be any combination of read-only, read-write, or write-only
depending on the particular implementation.
The one place where we were creating a PDBFile (in RawSession) is
updated to subclass ByteStream with a simple adapter that holds
a MemoryBuffer, and initializes the superclass with the buffer's
array, so that all the functionality of ByteStream works
transparently.
llvm-svn: 272370
looking for it along $PATH. This allows installs of LLVM tools outside of
$PATH to find the symbolizer and produce pretty backtraces if they crash.
llvm-svn: 272232
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
This is the simplest possible patch to get some kind of YAML
output. All it dumps is the MSF header fields so that in
theory an empty MSF file could be reconstructed.
Reviewed By: ruiu, majnemer
Differential Revision: http://reviews.llvm.org/D20971
llvm-svn: 271939
The data strucutre in the new FPO stream is described in the
PE/COFF spec. There is one record per function if frame pointer
is omitted.
Differential Revision: http://reviews.llvm.org/D20999
llvm-svn: 271926
This opens the door to introducing a YAML outputter which can be
used for machine consumption. Currently the yaml output style
is unimplemented and returns an error if you try to use it.
Reviewed By: rnk, ruiu
Differential Revision: http://reviews.llvm.org/D20967
llvm-svn: 271712
When printing line information and file checksums, we were printing
the file offset field from the struct header. This teaches
llvm-pdbdump how to turn those numbers into the filename. In the
case of file checksums, this is done by looking in the global
string table. In the case of line contributions, this is done
by indexing into the file names buffer of the DBI stream. Why
they use a different technique I don't know.
llvm-svn: 271630
To facilitate this, a couple of changes had to be made:
1. `ModuleSubstream` got moved from `DebugInfo/PDB` to
`DebugInfo/CodeView`, and various codeview related types are defined
there. It turns out `DebugInfo/CodeView/Line.h` already defines many of
these structures, but this is really old code that is not endian aware,
doesn't interact well with `StreamInterface` and not very helpful for
getting stuff out of a PDB. Eventually we should migrate the old readobj
`COFFDumper` code to these new structures, or at least merge their
functionality somehow.
2. A `ModuleSubstream` visitor is introduced. Depending on where your
module substream array comes from, different subsets of record types can
be expected. We are already hand parsing these substream arrays in many
places especially in `COFFDumper.cpp`. In the future we can migrate these
paths to the visitor as well, which should reduce a lot of code in
`COFFDumper.cpp`.
Differential Revision: http://reviews.llvm.org/D20936
Reviewed By: ruiu, majnemer
llvm-svn: 271621
This first pass only splits apart the records and dumps the line
info kinds and binary data. Subsequent patches will parse out
the binary data into more useful information and dump it in
detail.
llvm-svn: 271576
Unlike other sections that can grow to any size, the COFF section header
stream has maximum length because each record is fixed size and the COFF
file format limits the maximum number of sections. So I decided to not
create a specific stream class for it. Instead, I added a member function
to DbiStream class which returns a vector of COFF headers.
Differential Revision: http://reviews.llvm.org/D20717
llvm-svn: 271557
Adds the method MCStreamer::EmitBinaryData, which is usually an alias
for EmitBytes. In the MCAsmStreamer case, it is overridden to emit hex
dump output like this:
.byte 0x0e, 0x00, 0x08, 0x10
.byte 0x03, 0x00, 0x00, 0x00
.byte 0x00, 0x00, 0x00, 0x00
.byte 0x00, 0x10, 0x00, 0x00
Also, when verbose asm comments are enabled, this patch prints the dump
output for each comment before its record, like this:
# ArgList (0x1000) {
# TypeLeafKind: LF_ARGLIST (0x1201)
# NumArgs: 0
# Arguments [
# ]
# }
.byte 0x06, 0x00, 0x01, 0x12
.byte 0x00, 0x00, 0x00, 0x00
This should make debugging easier and testing more convenient.
Reviewers: aaboud
Subscribers: majnemer, zturner, amccarth, aaboud, llvm-commits
Differential Revision: http://reviews.llvm.org/D20711
llvm-svn: 271313
This converts remaining uses of ByteStream, which was still
left in the symbol stream and type stream, to using the new
StreamInterface zero-copy classes.
RecordIterator is finally deleted, so this is the only way left
now. Additionally, more error checking is added when iterating
the various streams.
With this, the transition to zero copy pdb access is complete.
llvm-svn: 271101
Since we want to move toward zero-copy access to stream data, we
want to remove all instances of copying operations. So get rid
of some of those here.
Differential Revision: http://reviews.llvm.org/D20720
Reviewed By: ruiu
llvm-svn: 270960
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