Commit Graph

22 Commits

Author SHA1 Message Date
David Blaikie 6dd452b514 DebugInfo: Fix skipping CUs in DWARFv5 debug_names table
My previoust test case had skipped CUs from one TU out of a two-TU LTO
scenario, which meant the CU index wasn't needed (as it was unambiguous
which CU a table entry applied to) - expanding the test to use 3 TUs,
skipping one (so long as it's not the last one) shows the indexes are
miscomputed. Fix that with a little indirection for the index.

llvm-svn: 340646
2018-08-24 20:31:05 +00:00
David Blaikie 66cf14d06b DebugInfo: Add metadata support for disabling DWARF pub sections
In cases where the debugger load time is a worthwhile tradeoff (or less
costly - such as loading from a DWP instead of a variety of DWOs
(possibly over a high-latency/distributed filesystem)) against object
file size, it can be reasonable to disable pubnames and corresponding
gdb-index creation in the linker.

A backend-flag version of this was implemented for NVPTX in
D44385/r327994 - which was fine for NVPTX which wouldn't mix-and-match
CUs. Now that it's going to be a user-facing option (likely powered by
"-gno-pubnames", the same as GCC) it should be encoded in the
DICompileUnit so it can vary per-CU.

After this, likely the NVPTX support should be migrated to the metadata
& the previous flag implementation should be removed.

Reviewers: aprantl

Differential Revision: https://reviews.llvm.org/D50213

llvm-svn: 339939
2018-08-16 21:29:55 +00:00
Pavel Labath 0120691f53 Fix build breakage from r337562
I changed a variable's type from pointer to reference, but forgot to
update the assert-only code.

llvm-svn: 337564
2018-07-20 15:40:24 +00:00
Pavel Labath 7f7e60694e DwarfDebug: Reduce duplication in addAccel*** methods
Summary:
Each of the four methods had a dozen lines and was doing almost exactly
the same thing: get the appropriate accelerator table kind and insert an
entry into it. I move this common logic to a helper function and make
these methods delegate to it.

This came up in the context of D49493, where I've needed to make adding
a string to a string pool slightly more complicated, and it seemed to
make sense to do it in one place instead of five.

To make this work I've needed to unify the interface of the AccelTable
data types, as some used to store DIE& and others DIE*. I chose to unify
to a reference as that's what the caller uses.

This technically isn't NFC, because it changes the StringPool used for
apple tables in the DWO case (now it uses the main file like DWARF v5
instead of the DWO file). However, that shouldn't matter, as DWO is not
a thing on apple targets (clang frontend simply ignores -gsplit-dwarf).

Reviewers: JDevlieghere, aprantl, probinson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49542

llvm-svn: 337562
2018-07-20 15:24:13 +00:00
Fangrui Song cb0bab86b3 [CodeGen] Fix inconsistent declaration parameter name
llvm-svn: 337200
2018-07-16 18:51:40 +00:00
Jonas Devlieghere 98062cb396 [AccelTable] Provide DWARF5AccelTableStaticData for dsymutil.
For dsymutil we want to store offsets in the accelerator table entries
rather than DIE pointers. In addition, we need a way to communicate
which CU a DIE belongs to. This patch provides support for both of these
issues.

Differential revision: https://reviews.llvm.org/D49102

llvm-svn: 337158
2018-07-16 10:52:27 +00:00
Jonas Devlieghere 3192e35b60 Revert "[AccelTable] Provide abstraction for emitting DWARF5 accelerator tables."
This reverts r336529 because an alternative approach turned out to be a
better fit for dsymuil.

llvm-svn: 336698
2018-07-10 16:18:56 +00:00
Jonas Devlieghere 5e810a878d [AccelTable] Provide abstraction for emitting DWARF5 accelerator tables.
When emitting the DWARF accelerator tables from dsymutil, we don't have
a DwarfDebug instance and we use a custom class to represent Dwarf
compile units. This patch adds an interface AccelTableWriterInfo to
abstract these from the Dwarf5AccelTableWriter, so we can have a custom
implementation for this in dsymutil.

Differential revision: https://reviews.llvm.org/D49031

llvm-svn: 336529
2018-07-09 09:08:44 +00:00
Jonas Devlieghere e60ca777b6 [AccelTable] Dwarf5AccelTableEmitter -> Writer (NFC)
Renames Dwarf5AccelTableEmitter to Dwarf5AccelTableWriter as suggested
in D49031.

llvm-svn: 336525
2018-07-09 08:47:38 +00:00
Pavel Labath 3fb39c79ed [CodeGen/Dwarf] Make debug_names compatible with split-dwarf
Summary:
Previously we crashed for the combination of the two features because we
tried to reference the dwo CU from the main object file. The fix
consists of two items:
- reference the skeleton CU from the name index (the consumer is
  expected to use the skeleton CU to find the real data).
- use the main object file string pool for the strings in the index

Reviewers: JDevlieghere, aprantl, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45566

llvm-svn: 330249
2018-04-18 12:11:59 +00:00
Pavel Labath eadfac8748 [CodeGen/AccelTable] Don't emit zero-CU name indexes
Summary:
If an input DICompileUnit is completely empty (e.g., the result of
running "clang -g" on an empty file), we don't bother emitting an empty
DWARF CU. When we do that, we must make sure we don't also emit a DWARF v5
name index, as DWARF specifies that each index must reference at least
one compilation unit.

Reviewers: JDevlieghere, aprantl, dblaikie

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45435

llvm-svn: 329575
2018-04-09 14:38:53 +00:00
Pavel Labath 6088c23431 Re-commit r329179 after fixing build&test issues
- MSVC was not OK with a static_assert referencing a non-static member
  variable, even though it was just in a sizeof(expression). I move the
  assert into the emit function, where it is probably more useful.
- Tests were failing in builds which did not have the X86 target
  configured. Since this functionality is not target-specific, I have
  removed the target specifiers from the .ll files.

llvm-svn: 329201
2018-04-04 14:42:14 +00:00
Nico Weber 55fcd07d25 Revert r329179 (and follow-up unsuccessful fix attempts 329184, 329186); it doesn't build.
llvm-svn: 329190
2018-04-04 13:06:22 +00:00
Pavel Labath 69baab103a [CodeGen] Generate DWARF v5 Accelerator Tables
Summary:
This patch adds a DwarfAccelTableEmitter class, which generates an
accelerator table, as specified in DWARF v5 standard. At the moment it
only generates a DIE offset column and (if we are indexing more than one
compile unit) a CU column.

Indexing type units is not currently supported, as we don't even have
the ability to generate DWARF v5-compatible compile units.

The implementation is not data-source agnostic like the one generating
apple tables. This was not necessary as we currently only have one user
of this code, and without a second user it was not obvious to me how to
best abstract this. (The difference between these tables and the apple
ones is that they need a lot more metadata about the debug info they are
indexing).

The generation is triggered by the --accel-tables argument, which
supersedes the --dwarf-accel-tables arg -- the latter was a simple
on-off switch, but not we can choose between two kinds of accelerator
tables we can generate.

This is tested by parsing the generated tables with llvm-dwarfdump and
the DWARFVerifier, and I've also checked that GNU readelf is able to
make sense of the tables.

Differential Revision: https://reviews.llvm.org/D43286

llvm-svn: 329179
2018-04-04 12:28:20 +00:00
Rafael Espindola 4b4d85fd4d Style update. NFC.
Rename 3 functions to start with lowercase letters. Don't repeat the
name in the comments.

llvm-svn: 328848
2018-03-29 23:32:54 +00:00
Pavel Labath a7c457d288 [CodeGen] Refactor AppleAccelTable
Summary:
This commit separates the abstract accelerator table data structure
from the code for writing out an on-disk representation of a specific
accelerator table format. The idea is that former (now called
AccelTable<T>) can be reused for the DWARF v5 accelerator tables
as-is, without any further customizations.

Some bits of the emission code (now living in the EmissionContext class)
can be reused for DWARF v5 as well, but the subtle differences in the
layout of various subtables mean the sharing is not always possible.
(Also, the individual emit*** functions are fairly simple so there's a
tradeoff between making a bigger general-purpose function, and two
smaller targeted functions.)

Another advantage of this setup is that more of the serialization logic
can be hidden in the .cpp file -- I have moved declarations of the
header and all the emission functions there.

Reviewers: JDevlieghere, aprantl, probinson, dblaikie

Subscribers: echristo, clayborg, vleschuk, llvm-commits

Differential Revision: https://reviews.llvm.org/D43285

llvm-svn: 325516
2018-02-19 16:12:20 +00:00
Pavel Labath 062eb53781 [CodeGen] Optimize AccelTable
Summary:
The class contained arrays of two structures (DataArray and HashData).
These structures were in 1:1 correspondence, and one of them contained
pointers to the other (and *both* contained a "Name" field). By merging
these two structures into one, we can save a bit of space without
negatively impacting much of anything.

Reviewers: JDevlieghere, aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43073

llvm-svn: 324724
2018-02-09 10:06:56 +00:00
Jonas Devlieghere 1ce64dcc64 [AccelTable] Move print methods to implementation. NFC
This patch moves the implementation of the print methods from the header
to the cpp file.

llvm-svn: 323757
2018-01-30 13:36:30 +00:00
Jonas Devlieghere 073971b243 [AccelTable] Workaround for MSVC bug
Microsoft Visual Studio rejects the static constexpr static list of
atoms even though it's valid C++. This provides a workaround to unbreak
the bots.

llvm-svn: 323667
2018-01-29 17:28:51 +00:00
Jonas Devlieghere ba8daf0964 [AccelTable] Try making MSVC happy
MSVC complains that the constexpr "expression did not evaluate to a
constant". Trying to make it happy by adding a `const` specifier as
suggested in https://stackoverflow.com/questions/37574343.

llvm-svn: 323659
2018-01-29 15:23:34 +00:00
Jonas Devlieghere 5ead3a2b07 [dsymutil] Generate Apple accelerator tables
This patch adds support for generating accelerator tables in dsymutil.
This feature was already present in our internal repository but not yet
upstreamed because it requires changes to the Apple accelerator table
implementation.

Differential revision: https://reviews.llvm.org/D42501

llvm-svn: 323655
2018-01-29 14:52:50 +00:00
Jonas Devlieghere 855fc3bbca [NFC] Rename DwarfAccelTable and move header.
This patch renames DwarfAccelTable.{h,cpp} to AccelTable.{h,cpp} and
moves the header to the include dir so it is accessible by the
dsymutil implementation.

Differential revision: https://reviews.llvm.org/D42529

llvm-svn: 323654
2018-01-29 14:52:41 +00:00