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
When merging in types from a type server PDB, we would use a
pointer into the type server PDB's mapped file buffer directly
to avoid copying data. However, we would close the type server
PDB after we finished merging in its types, which would unmap
all of its memory. This would lead to a use after free.
We fix this by making a strong reference in the PDBLinker class
to all referenced type server PDBs, thereby making it safe to
hold pointers into its memory mapped contents.
This fixes llvm.org/pr36455
Differential Revision: https://reviews.llvm.org/D43834
llvm-svn: 326345
Summary: Instead of fatal-ing out when missing a type server PDB, insead warn and cache the miss.
Reviewers: rnk, zturner
Reviewed By: rnk
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42188
llvm-svn: 323893
There's some abstraction overhead in the underlying
mechanisms that were being used, and it was leading to an
abundance of small but not-free copies being made. This
showed up on a profile. Eliminating this and going back to
a low-level byte-based implementation speeds up lld with
/DEBUG between 10 and 15%.
Differential Revision: https://reviews.llvm.org/D42148
llvm-svn: 322871
The classes used to print and update time information are in
common, so other linkers could use this as well if desired.
Differential Revision: https://reviews.llvm.org/D41915
llvm-svn: 322736
This is not a record type that clang currently generates,
but it is a record that is encountered in object files generated
by cl. This record is unusual in that it refers directly to
the string table instead of indirectly to the string table via
the FileChecksums table. Because of this, it was previously
overlooked and we weren't remapping the string indices at all.
This would lead to crashes in MSVC when trying to display a
variable whose debug info involved an S_FILESTATIC.
Original bug report by Alexander Ganea
Differential Revision: https://reviews.llvm.org/D41718
llvm-svn: 321883
This adds the /DEBUG:GHASH option to LLD which will look for
the existence of .debug$H sections in linker inputs and use them
to accelerate type merging. The clang-cl side has already been
added, so this completes the work necessary to begin experimenting
with this feature.
Differential Revision: https://reviews.llvm.org/D40980
llvm-svn: 320719
A couple of places in LLD were passing references to
TypeTableCollections around, which makes it hard to change the
implementation at runtime. However, these cases only needed to
iterate over the types in the collection, and TypeCollection
already provides a handy abstract interface for this purpose.
By implementing this interface, we can get rid of the need to
pass TypeTableBuilder references around, which should allow us
to swap the implementation at runtime in subsequent patches.
llvm-svn: 319345
Now that we have only SymbolBody as the symbol class. So, "SymbolBody"
is a bit strange name now. This is a mechanical change generated by
perl -i -pe s/SymbolBody/Symbol/g $(git grep -l SymbolBody lld/ELF lld/COFF)
nd clang-format-diff.
Differential Revision: https://reviews.llvm.org/D39459
llvm-svn: 317370
Summary:
The COFF linker and the ELF linker have long had similar but separate
Error.h and Error.cpp files to implement error handling. This change
introduces new error handling code in Common/ErrorHandler.h, changes the
COFF and ELF linkers to use it, and removes the old, separate
implementations.
Reviewers: ruiu
Reviewed By: ruiu
Subscribers: smeenai, jyknight, emaste, sdardis, nemanjai, nhaehnle, mgorny, javed.absar, kbarton, fedor.sergeev, llvm-commits
Differential Revision: https://reviews.llvm.org/D39259
llvm-svn: 316624
The type index is from the TPI stream, not the IPI stream. Fix the
dumper, fix type index discovery, and add a test in LLD.
Also improve the log message we emit when we fail to rewrite type
indices in LLD. That's how I found this bug.
llvm-svn: 316461
Previously, our algorithm to compute a build id involved hashing the
executable and storing that as the GUID in the CV Debug Record chunk,
and setting the age to 1.
This breaks down in one very obvious case: a user adds some newlines to
a file, rebuilds, but changes nothing else. This causes new line
information and new file checksums to get written to the PDB, meaning
that the debug info is different, but the generated code would be the
same, so we would write the same build over again with an age of 1.
Anyone using a symbol cache would have a problem now, because the
debugger would open the executable, look at the age and guid, find a
matching PDB in the symbol cache and then load it. It would never copy
the new PDB to the symbol cache.
This patch implements the canonical Windows algorithm for updating
a build id, which is to check the existing executable first, and
re-use an existing GUID while bumping the age if it already
exists.
Differential Revision: https://reviews.llvm.org/D36758
llvm-svn: 310961
We don't have the right algorithm for copying S_UDT symbols
from object files to the globals stream, and having it wrong
is worse than not having it at all, since it breaks display
of local variables of UDT types (for example, "dv Foo" fails
in our current implementation, but succeeds if the S_UDT records
are omitted). Omit them until we fix the algorithm.
llvm-svn: 310867
The linker module contains a symbol of type S_COMPILE3 which
contains various information about the compiler and linker used
to create the PDB, such as the name of the linker, the target
machine, and the linker version. Interestingly, if we set the
version string to 0.0.0.0, then when trying to view local
variables WinDbg emits an error that private symbols are not
present. By setting this to a valid MSVC linker version string,
local variables can display.
As such, even though it is not representative of LLVM's version
information, we need this for compatibility.
llvm-svn: 310755
PDBs need to contain 1 module for each object file/compiland,
and a special one synthesized by the linker. This one contains
a symbol record for each output section in the executable with
its address information. This patch adds such symbols to the
linker module. Note that we also are supposed to add an
S_COFFGROUP symbol for what appears to be each input section that
contributes to each output section, but it's not entirely clear
how to generate these yet, so I'm leaving that for a separate
patch.
llvm-svn: 310754
Previously we were writing an empty globals stream. Windows
tools interpret this as "private symbols are not present in
this PDB", even when they are, so we need to fix this. Regardless,
without it we don't have information about global variables, so
we need to fix it anyway. This patch does that.
With this patch, the "lm" command in WinDbg correctly reports
that we have private symbols available, but the "dv" command
still refuses to display local variables.
Differential Revision: https://reviews.llvm.org/D36535
llvm-svn: 310743
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
The compiler outputs PROC32_ID symbols into the object files
for functions, and these symbols have an embedded type index
which, when copied to the PDB, refer to the IPI stream. However,
the symbols themselves are also converted into regular symbols
(e.g. S_GPROC32_ID -> S_GPROC32), and type indices in the regular
symbol records refer to the TPI stream. So this patch applies
two fixes to function records.
1. It converts ID symbols to the proper non-ID record type.
2. After remapping the type index from the object file's index
space to the PDB file/IPI stream's index space, it then
remaps that index to the TPI stream's index space by.
Besides functions, during the remapping process we were also
discarding symbol record types which we did not recognize.
In particular, we were discarding S_BPREL32 records, which is
what MSVC uses to describe local variables on the stack. So
this patch fixes that as well by copying them to the PDB.
Differential Revision: https://reviews.llvm.org/D36426
llvm-svn: 310394
Summary:
PDB section contributions are supposed to use output section indices and
offsets, not input section indices and offsets.
This allows the debugger to look up the index of the module that it
should look up in the modules stream for symbol information. With this
change, windbg can now find line tables, but it still cannot print local
variables.
Fixes PR34048
Reviewers: zturner
Subscribers: hiraditya, ruiu, llvm-commits
Differential Revision: https://reviews.llvm.org/D36285
llvm-svn: 309987
We don't write any actual symbols to this stream yet, but for
now we just create the stream and hook it up to the appropriate
places and give it a valid header.
Differential Revision: https://reviews.llvm.org/D35290
llvm-svn: 309608
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
Assume that the LF_TYPESERVER2 record contains Windows-style paths. In
any case, 'sys::path::filename(Path, Style::windows)' will work on
Unix-style paths.
llvm-svn: 308241
Summary:
Object files compiled with /Zi emit type information into a type server
PDB. The .debug$S section will contain a single TypeServer2Record with
the absolute path and GUID of the type server. LLD needs to load the
type server PDB and merge all types and items it finds in it into the
destination PDB.
Depends on D35495
Reviewers: ruiu, inglorion
Subscribers: zturner, llvm-commits
Differential Revision: https://reviews.llvm.org/D35504
llvm-svn: 308235
Summary:
We were treating the GUIDs in TypeServer2Record as strings, and the
non-ASCII bytes in the GUID would not round-trip through YAML.
We already had the PDB_UniqueId type portably represent a Windows GUID,
but we need to hoist that up to the DebugInfo/CodeView library so that
we can use it in the TypeServer2Record as well as in PDB parsing code.
Reviewers: inglorion, amccarth
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D35495
llvm-svn: 308234
Summary:
Instead of wiring these through the CVTypeVisitor interface, clients
should inspect the CVTypeArray before visiting it and potentially load
up the type server's TPI stream if they need it.
No tests relied on this functionality because LLD was the only client.
Reviewers: ruiu
Subscribers: mgorny, hiraditya, zturner, llvm-commits
Differential Revision: https://reviews.llvm.org/D35394
llvm-svn: 308212
Summary:
We've accumulated about five or so data structures that are widely
referenced:
- PDBBuilder
- Type table
- Id table
- PDB string table
- Type server handler
I'm about to rewrite type server handling, and I need a new class in LLD
where I can put its state. By creating a new PDBLinker class, I hope to
put it there next.
Reviewers: ruiu
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35392
llvm-svn: 307979
Summary:
This fixes type indices for SDK or CRT static archives. Previously we'd
try to look next to the archive object file path, which would not exist
on the local machine.
Also error out if we can't resolve a type server record. Hypothetically
we can recover from this error by discarding debug info for this object,
but that is not yet implemented.
Reviewers: ruiu, amccarth
Subscribers: aprantl, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D35369
llvm-svn: 307946
Revert "[PDB] Tweak bad type index error handling"
check-lld with asan detects use-after-poison.
This reverts commits r307733 and r307726.
llvm-svn: 307752
Translate invalid type indices to a sentinel value instead of skipping
the record. Skipping records isn't a good recovery method, because we
can skip a scope open or close record, which will confuse the scope
management code.
We currently have lots of invalid type indices on Microsoft-provided
standard libraries, because the LF_TYPESERVER2 records contain absolute
paths that are only valid on their build servers. Our type server
handlers need to look at other things (GUIDs) to find these type server
PDBs.
llvm-svn: 307726
This is part of the continuing effort to increase parity between
LLD and MSVC PDBs. link still doesn't like our PDBs, so the most
obvious thing to check was whether adding an empty publics stream
would get it to do something else. It still fails in the same way
but at least this removes one more variable from the equation.
The next logical step would be to try creating an empty globals
stream.
Differential Revision: https://reviews.llvm.org/D35224
llvm-svn: 307598
lld-link is apparently a symlink to lld. Our pdb writing code
uses llvm::sys::fs::getMainExecutable() and writes that value
into the PDB, which will resolve symlinks etc. But what we
really want is the exact value of argv[0], which matches what
the MS linker does. Fix this by just writing argv[0] instead
of calling getMainExecutable.
llvm-svn: 307592
Zachary Turner