Commit Graph

17 Commits

Author SHA1 Message Date
Greg Clayton e6ddde57e2 Fix a regression in DWARF access speed caused by svn revision 356190
The issue was caused by the error checking code that was added. It was incorrectly adding an extra abbreviation when DWARFEnumState::Complete was received since it would push an extra abbreviation onto the list with the abbreviation code of zero. This cause m_idx_offset in each DWARFAbbreviationDeclarationSet to be set to UINT32_MAX. This valid indicates we must linearly search for attributes, not access them in O(1) time. This caused every DWARFDebugInfoEntry that would try to get its DWARFAbbreviationDeclaration from the CU's DWARFAbbreviationDeclarationSet to always linearly search the abbreviation set for a given abbreviation code. Easy to see why this would cause things to be slow.

This regression was caused by: https://reviews.llvm.org/D59370. I asked to ensure there was no regression is parsing or access speed, but that must not have been done. In my test with 40 DWARF files trying to set a breakpoint by function name and in a header file, I see a 8% speed improvement with this fix.

There was no regression in correctness, just very inefficient access.

Added full unit testing for DWARFAbbreviationDeclarationSet parsing to ensure this doesn't regress.

Differential Revision: https://reviews.llvm.org/D62630

llvm-svn: 362105
2019-05-30 15:32:33 +00:00
Konrad Kleine 248a13057a [lldb] NFC modernize codebase with modernize-use-nullptr
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.

This is the command I ran and I to fix and format the code base:

```
run-clang-tidy.py \
	-header-filter='.*' \
	-checks='-*,modernize-use-nullptr' \
	-fix ~/dev/llvm-project/lldb/.* \
	-format \
	-style LLVM \
	-p ~/llvm-builds/debug-ninja-gcc
```

NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.

NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.

Reviewers: martong, espindola, shafik, #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D61847

llvm-svn: 361484
2019-05-23 11:14:47 +00:00
Jonas Devlieghere 8b3af63b89 [NFC] Remove ASCII lines from comments
A lot of comments in LLDB are surrounded by an ASCII line to delimit the
begging and end of the comment.

Its use is not really consistent across the code base, sometimes the
lines are longer, sometimes they are shorter and sometimes they are
omitted. Furthermore, it looks kind of weird with the 80 column limit,
where the comment actually extends past the line, but not by much.
Furthermore, when /// is used for Doxygen comments, it looks
particularly odd. And when // is used, it incorrectly gives the
impression that it's actually a Doxygen comment.

I assume these lines were added to improve distinguishing between
comments and code. However, given that todays editors and IDEs do a
great job at highlighting comments, I think it's worth to drop this for
the sake of consistency. The alternative is fixing all the
inconsistencies, which would create a lot more churn.

Differential revision: https://reviews.llvm.org/D60508

llvm-svn: 358135
2019-04-10 20:48:55 +00:00
Zachary Turner 611d1f98c5 Delete more dead code.
All of this is code that is unreferenced.  Removing as much of
this as possible makes it more easy to determine what functionality
is missing and/or shared between LLVM and LLDB's DWARF interfaces.

llvm-svn: 356509
2019-03-19 20:08:56 +00:00
Zachary Turner aea0985814 Delete dead code.
Most of these are Dump functions that are never called, but there
is one instance of entire unused classes (DWARFDebugMacinfo and
DWARFDebugMacinfoEntry) which are also unreferenced in the codebase).

Differential Revision: https://reviews.llvm.org/D59276

llvm-svn: 356490
2019-03-19 18:06:32 +00:00
Zachary Turner bb26a7eb11 Return llvm::Error and llvm::Expected from DWARF parsing code.
The goal here is to improve our error handling and error recovery while
parsing DWARF, while at the same time getting us closer to being able to
merge LLDB's DWARF parser with LLVM's. To this end, I've udpated several
of the low-level parsing functions in LLDB to return llvm::Error and
llvm::Expected.

For now, this only updates LLDB parsing functions and not LLVM. In some
ways, this actually gets us *farther* from parity with the two
interfaces, because prior to this patch, at least the parsing interfaces
were the same (i.e. they all just returned bools, and now with this
patch they're diverging). But, I chose to do this for two primary
reasons.

LLDB has error logging code engrained deep within some of its parsing
functions. We don't want to lose this logging information, but obviously
LLVM has no logging mechanism at all. So if we're to merge the
interfaces, we have to find a way to still allow LLDB to properly report
parsing errors while not having the reporting code be inside of LLVM.
LLDB (and indeed, LLVM) overload the meaning of the false return value
from all of these extraction functions to mean both "We reached the null
entry at the end of a list of items, therefore everything was
successful" as well as "something bad and unrecoverable happened during
parsing". So you would have a lot code that would do something like:
while (foo.extract(...)) {
  ...
}

But when the loop stops, why did it stop? Did it stop because it
finished parsing, or because there was an error? Because of this, in
some cases we don't always know whether it is ok to proceed, or how to
proceed, but we were doing it anyway.

In this patch, I solve the second problem by introducing an
enumeration called DWARFEnumState which has two values MoreItems and
Complete. Both of these indicate success, but the latter indicates
that we reached the null entry. Then, I return this value instead of
bool, and convey parsing failure separately.

To solve the first problem (and convey parsing failure) these
functions now return either llvm::Error or llvm::Expected<DWARFEnumState>.
Having this extra bit of information allows us to properly convey all 3 of
"error, bail out", "success, call this function again", and "success,
don't call this function again".

In subsequent patches I plan to extend this pattern to the rest of the
parsing interfaces, which will ultimately get all of the log statements
and error reporting out of the low level parsing code and into the high
level parsing code (e.g. SymbolFileDWARF, DWARFASTParserClang, etc).

Eventually, these same changes will have to be backported to LLVM's
DWARF parser, but diverging in the short term is the easiest way to
converge in the long term.

Differential Revision: https://reviews.llvm.org/D59370

llvm-svn: 356190
2019-03-14 19:05:55 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Adrian Prantl 05097246f3 Reflow paragraphs in comments.
This is intended as a clean up after the big clang-format commit
(r280751), which unfortunately resulted in many of the comment
paragraphs in LLDB being very hard to read.

FYI, the script I used was:

import textwrap
import commands
import os
import sys
import re
tmp = "%s.tmp"%sys.argv[1]
out = open(tmp, "w+")
with open(sys.argv[1], "r") as f:
  header = ""
  text = ""
  comment = re.compile(r'^( *//) ([^ ].*)$')
  special = re.compile(r'^((([A-Z]+[: ])|([0-9]+ )).*)|(.*;)$')
  for line in f:
      match = comment.match(line)
      if match and not special.match(match.group(2)):
          # skip intentionally short comments.
          if not text and len(match.group(2)) < 40:
              out.write(line)
              continue

          if text:
              text += " " + match.group(2)
          else:
              header = match.group(1)
              text = match.group(2)

          continue

      if text:
          filled = textwrap.wrap(text, width=(78-len(header)),
                                 break_long_words=False)
          for l in filled:
              out.write(header+" "+l+'\n')
              text = ""

      out.write(line)

os.rename(tmp, sys.argv[1])

Differential Revision: https://reviews.llvm.org/D46144

llvm-svn: 331197
2018-04-30 16:49:04 +00:00
Jan Kratochvil b14f1da23c Fix LLDB crash accessing unknown DW_FORM_* attributes
Current LLDB (that is without DWZ support) crashes accessing Fedora debug info:
READ of size 8 at 0x60200000ffc8 thread T0
    #0 in DWARFDebugInfoEntry::BuildAddressRangeTable(SymbolFileDWARF*, DWARFCompileUnit const*, DWARFDebugAranges*) const tools/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp:1336

Greg Clayton: We will need a warning to be emitted in
SymbolFileDWARF::CalculateAbilities() stating we won't parse the DWARF due to
"unsupported DW_FORM value of 0x1f20".

Patch has been mostly written by Greg Clayton.

Differential revision: https://reviews.llvm.org/D35622

llvm-svn: 309581
2017-07-31 17:02:52 +00:00
Zachary Turner bf9a77305f Move classes from Core -> Utility.
This moves the following classes from Core -> Utility.

ConstString
Error
RegularExpression
Stream
StreamString

The goal here is to get lldbUtility into a state where it has
no dependendencies except on itself and LLVM, so it can be the
starting point at which to start untangling LLDB's dependencies.
These are all low level and very widely used classes, and
previously lldbUtility had dependencies up to lldbCore in order
to use these classes.  So moving then down to lldbUtility makes
sense from both the short term and long term perspective in
solving this problem.

Differential Revision: https://reviews.llvm.org/D29427

llvm-svn: 293941
2017-02-02 21:39:50 +00:00
Kate Stone b9c1b51e45 *** This commit represents a complete reformatting of the LLDB source code
*** to conform to clang-format’s LLVM style.  This kind of mass change has
*** two obvious implications:

Firstly, merging this particular commit into a downstream fork may be a huge
effort.  Alternatively, it may be worth merging all changes up to this commit,
performing the same reformatting operation locally, and then discarding the
merge for this particular commit.  The commands used to accomplish this
reformatting were as follows (with current working directory as the root of
the repository):

    find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} +
    find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ;

The version of clang-format used was 3.9.0, and autopep8 was 1.2.4.

Secondly, “blame” style tools will generally point to this commit instead of
a meaningful prior commit.  There are alternatives available that will attempt
to look through this change and find the appropriate prior commit.  YMMV.

llvm-svn: 280751
2016-09-06 20:57:50 +00:00
Ed Maste eeae72184b Introduce DWARFDataExtractor for 64-Bit DWARF parsing
Review: http://llvm-reviews.chandlerc.com/D2007
llvm-svn: 193368
2013-10-24 20:43:47 +00:00
Greg Clayton c7bece56fa <rdar://problem/13069948>
Major fixed to allow reading files that are over 4GB. The main problems were that the DataExtractor was using 32 bit offsets as a data cursor, and since we mmap all of our object files we could run into cases where if we had a very large core file that was over 4GB, we were running into the 4GB boundary.

So I defined a new "lldb::offset_t" which should be used for all file offsets.

After making this change, I enabled warnings for data loss and for enexpected implicit conversions temporarily and found a ton of things that I fixed.

Any functions that take an index internally, should use "size_t" for any indexes and also should return "size_t" for any sizes of collections.

llvm-svn: 173463
2013-01-25 18:06:21 +00:00
Greg Clayton 710dd5aebf Spelling changes applied from lldb_spelling.diffs from Bruce Mitchener.
Thanks Bruce!

llvm-svn: 123083
2011-01-08 20:28:42 +00:00
Greg Clayton 016a95eb04 Looking at some of the test suite failures in DWARF in .o files with the
debug map showed that the location lists in the .o files needed some 
refactoring in order to work. The case that was failing was where a function
that was in the "__TEXT.__textcoal_nt" in the .o file, and in the 
"__TEXT.__text" section in the main executable. This made symbol lookup fail
due to the way we were finding a real address in the debug map which was
by finding the section that the function was in in the .o file and trying to
find this in the main executable. Now the section list supports finding a
linked address in a section or any child sections. After fixing this, we ran
into issue that were due to DWARF and how it represents locations lists. 
DWARF makes a list of address ranges and expressions that go along with those
address ranges. The location addresses are expressed in terms of a compile
unit address + offset. This works fine as long as nothing moves around. When
stuff moves around and offsets change between the remapped compile unit base
address and the new function address, then we can run into trouble. To deal
with this, we now store supply a location list slide amount to any location
list expressions that will allow us to make the location list addresses into
zero based offsets from the object that owns the location list (always a
function in our case). 

With these fixes we can now re-link random address ranges inside the debugger
for use with our DWARF + debug map, incremental linking, and more.

Another issue that arose when doing the DWARF in the .o files was that GCC
4.2 emits a ".debug_aranges" that only mentions functions that are externally
visible. This makes .debug_aranges useless to us and we now generate a real
address range lookup table in the DWARF parser at the same time as we index
the name tables (that are needed because .debug_pubnames is just as useless).
llvm-gcc doesn't generate a .debug_aranges section, though this could be 
fixed, we aren't going to rely upon it.

Renamed a bunch of "UINT_MAX" to "UINT32_MAX".

llvm-svn: 113829
2010-09-14 02:20:48 +00:00
Greg Clayton 6b6742b08e Remove extraneous semicolon after if condition (from Jean-Daniel Dupas).
llvm-svn: 107694
2010-07-06 20:30:35 +00:00
Chris Lattner 30fdc8d841 Initial checkin of lldb code from internal Apple repo.
llvm-svn: 105619
2010-06-08 16:52:24 +00:00