llvm-project.git/llvm/lib/DebugInfo/DWARF/DWARFListTable.cpp, branch users/nico/python-2

[DebugInfo] Expand ability to load 2-byte addresses in dwarf sections

2021-10-22T00:31:00+00:00

Some dwarf loaders in LLVM are hard-coded to only accept 4-byte and 8-byte address sizes. This patch generalizes acceptance into `DWARFContext::isAddressSizeSupported` and provides a common way to generate rejection errors.

The MSP430 target has been given new tests to cover dwarf loading cases that previously failed due to 2-byte addresses.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D111953

[WIP][DebugInfo] Lazily parse debug_loclist offsets

2020-08-18T17:49:39+00:00

Parsing DWARFv5 debug_loclist offsets when a CU is parsed is weighing
down memory usage of symbolizers that don't need to parse this data at
all. There's not much benefit to caching these anyway - since they are
O(1) lookup and reading once you know where the offset list starts (and
can do bounds checking with the offset list size too).

In general, I think it might be time to start paying down some of the
technical debt of loc/loclist/range/rnglist parsing to try to unify it a
bit more.

eg:

* Currently DWARFUnit has: RangeSection, RangeSectionBase, LocSection,
  LocSectionBase, LocTable, RngListTable, LoclistTableHeader (be nice if
  these were all wrapped up in two variables - one for loclists, one for
  rnglists)

* rnglists and loclists are handled differently (see:
  LoclistTableHeader, but no RnglistTableHeader)

* maybe all these types could be less stateful - lazily parse what they
  need to, even reparsing rather than caching because it doesn't seem
  too expensive, for instance. (though admittedly so long as it's
  constantcost/overead per compilatiton that's probably adequate)

* Maybe implementing and using a DWARFDataExtractor that can be
  sub-ranged (so we could slice it up to just the single contribution) -
  though maybe that's not so useful because loc/ranges need to refer to
  it by absolute, not contribution-relative mechanisms

Differential Revision: https://reviews.llvm.org/D86110

[DebugInfo] Fix a possible crash when reading a malformed .debug_*lists section.

2020-07-14T09:35:17+00:00

DWARFListTableHeader::length() handles the zero value of HeaderData.Length
in a special way, which makes the result different from the calculated
value of FullLength, which leads to triggering an assertion. The patch
moves the assertion a bit later when `FullLength` is already checked for
minimal allowed value.

Differential Revision: https://reviews.llvm.org/D82886

[DebugInfo] Report the format of location and range lists [9/10]

2020-06-02T10:55:31+00:00

Differential Revision: https://reviews.llvm.org/D80523

[DebugInfo] Dump values in .debug_loclists and .debug_rnglists according to the DWARF format (5/8).

2020-05-19T06:35:41+00:00

The patch changes dumping of a unit_length field and offsets in headers
in .debug_loclists and .debug_rnglists sections so that they are printed
as 16-digit hex values if the contribution is in the DWARF64 format.

Differential Revision: https://reviews.llvm.org/D79997

[DWARF] Use getInitialLength in range list parsing

2020-03-02T10:18:12+00:00

Summary:
This could be considered obvious, but I am putting it up to illustrate
the usefulness/impact of the getInitialLength change.

Reviewers: dblaikie, jhenderson, ikudrin

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75117

[DWARF] Support DWARF64 in DWARFListTableHeader.

2019-09-05T06:49:05+00:00

This enables 64-bit DWARF support for parsing range and location list tables.

Differential Revision: https://reviews.llvm.org/D66643

llvm-svn: 371014

Switch LLVM to use 64-bit offsets (2/5)

2019-08-06T10:49:40+00:00

This updates all libraries and tools in LLVM Core to use 64-bit offsets
which directly or indirectly come to DataExtractor.

Differential Revision: https://reviews.llvm.org/D65638

llvm-svn: 368014

[DWARF][NFC] Add constants for reserved values of an initial length field.

2019-07-24T11:34:29+00:00

Differential Revision: https://reviews.llvm.org/D65039

llvm-svn: 366887

[DWARF][RISCV] Add support for RISC-V relocations needed for debug info

2019-07-18T05:22:55+00:00

When code relaxation is enabled many RISC-V fixups are not resolved but
instead relocations are emitted. This happens even for DWARF debug
sections. Therefore, to properly support the parsing of DWARF debug info
we need to be able to resolve RISC-V relocations. This patch adds:

* Support for RISC-V relocations in RelocationResolver
* DWARF support for two relocations per object file offset
* DWARF changes to support relocations in more DIE fields

The two relocations per offset change is needed because some RISC-V
relocations (used for label differences) come in pairs.

Relocations can also be emitted for DWARF fields where relocations were
not yet evaluated. Adding relocation support for some of these fields is
essencial. On the other hand, LLVM currently emits RISC-V relocations
for fixups that could be safely evaluated, since they can never be
affected by code relaxations. This patch also adds relocation support
for the fields affected by those extraneous relocations (the DWARF unit
entry Length, and the DWARF debug line entry TotalLength and
PrologueLength), for testing purposes.

Differential Revision: https://reviews.llvm.org/D62062
Patch by Luís Marques.

llvm-svn: 366402