llvm-project/llvm/test/DebugInfo/PDB
Zachary Turner 579264bd59 Support skewed stream arrays.
VarStreamArray was built on the assumption that it is backed by a
StreamRef, and offset 0 of that StreamRef is the first byte of the first
record in the array.

This is a logical and intuitive assumption, but unfortunately we have
use cases where it doesn't hold. Specifically, a PDB module's symbol
stream is prefixed by 4 bytes containing a magic value, and the first
byte of record data in the array is actually at offset 4 of this byte
sequence.

Previously, we would just truncate the first 4 bytes and then construct
the VarStreamArray with the resulting StreamRef, so that offset 0 of the
underlying stream did correspond to the first byte of the first record,
but this is problematic, because symbol records reference other symbol
records by the absolute offset including that initial magic 4 bytes. So
if another record wants to refer to the first record in the array, it
would say "the record at offset 4".

This led to extremely confusing hacks and semantics in loading code, and
after spending 30 minutes trying to get some math right and failing, I
decided to fix this in the underlying implementation of VarStreamArray.
Now, we can say that a stream is skewed by a particular amount. This
way, when we access a record by absolute offset, we can use the same
values that the records themselves contain, instead of having to do
fixups.

Differential Revision: https://reviews.llvm.org/D55344

llvm-svn: 348499
2018-12-06 16:55:00 +00:00
..
DIA [PDB] Fix this test for real. 2018-09-30 03:57:49 +00:00
Inputs [PDB] Fix another bug in globals stream name lookup. 2018-10-09 21:19:03 +00:00
Native [PDB] Add support for dumping Typedef records. 2018-10-01 17:55:38 +00:00
dbi-bytes.test
dump-fpm.test
every-type.test [PDB] Add the ability to map forward references to full decls. 2018-09-20 15:50:13 +00:00
just-my-code.test
module-bytes.test Support skewed stream arrays. 2018-12-06 16:55:00 +00:00
module-stats.test
obj-globalhash.test Resubmit [pdb] Change /DEBUG:GHASH to emit 8 byte hashes." 2018-05-17 22:55:15 +00:00
pdb-invalid-type.test [DebugInfo] Common behavior for error types 2018-08-31 17:41:58 +00:00
pdb-longname-truncation.test
pdb-minimal-construct.test
pdb-resolve-forward-refs.test [PDB] Add the ability to map forward references to full decls. 2018-09-20 15:50:13 +00:00
pdb-unknown-symbol.test
pdb-yaml-symbols.test
pdbdump-debug-subsections.test
pdbdump-global-lookup.test [PDB] Fix another bug in globals stream name lookup. 2018-10-09 21:19:03 +00:00
pdbdump-globals-empty.test
pdbdump-headers.test [PDB] Add the ability to map forward references to full decls. 2018-09-20 15:50:13 +00:00
pdbdump-merge-ids-and-types.test
pdbdump-mergeids.test
pdbdump-mergetypes.test
pdbdump-objfilename.yaml
pdbdump-raw-blocks.test
pdbdump-raw-bytes.test
pdbdump-raw-stream.test
pdbdump-readwrite.test
pdbdump-source-names.test
pdbdump-write.test
pdbdump-yaml-types.test
pdbdump-yaml.test
section-headers.test
tpi-bytes.test
udt-stats.test
using-namespace.test [CodeView] Minimal support for S_UNAMESPACE records 2018-07-31 19:15:50 +00:00
write-fpm.test [MSF] Default to FPM2, and always mark FPM pages allocated. 2018-03-29 18:34:15 +00:00