Commit Graph

76 Commits

Author SHA1 Message Date
Adrian Prantl 681466f5e6 Allow lldb-test to combine -find with -dump-clang-ast
This patch threads an lldb::DescriptionLevel through the typesystem to
allow dumping the full Clang AST (level=verbose) of any lldb::Type in
addition to the human-readable source description (default
level=full). This type dumping interface is currently not exposed
through the SBAPI.

The application is to let lldb-test dump the clang AST of search
results. I need this to test lazy type completion of clang types in
subsequent patches.

Differential Revision: https://reviews.llvm.org/D78329
2020-04-17 11:01:20 -07:00
Davide Italiano 1fae85a853 [DWARF] Add instructions to regenerate this test, if needed. 2020-04-16 13:31:32 -07:00
Davide Italiano 8cac6d1875 [Shell] Remove incorrectly cargo-culted UNSUPPORTED.
Let's see if this sticks on the bots.
2020-04-16 13:22:46 -07:00
David Blaikie 208a11ab3a Reapply "llvm-dwarfdump: Report errors when failing to parse loclist/debug_loc entries""
Originally committed as 416fa7720e
Reverted (due to buildbot failure - breaking lldb) in 7a45aeacf3.

I still can't seem to build lldb locally, but Pavel Labath has kindly
provided a potential fix to preserve the old behavior in lldb by
registering a simple recoverable error handler there that prints to the
desired stream in lldb, rather than stderr.
2020-04-14 14:44:32 -07:00
Adrian Prantl 143d507c9f Preserve the owning module information from DWARF in the synthesized AST
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
1;95;0csets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.

This reapplies the previously reverted commit, but without support for
ClassTemplateSpecializations, which I'm going to look into separately.

rdar://problem/59634380

Differential Revision: https://reviews.llvm.org/D75488
2020-04-09 11:09:44 -07:00
Davide Italiano d51b38f1b3 [DWARF] Not all the constant variables are "static".
Fixes rdar://problem/61402307

Differential Revision: https://reviews.llvm.org/D77698
2020-04-08 11:07:19 -07:00
Kazuaki Ishizaki e9264b746b [lldb] NFC: Fix trivial typo in comments, documents, and messages
Differential Revision: https://reviews.llvm.org/D77460
2020-04-07 01:06:16 +09:00
Adrian Prantl 32672b877d Revert "Preserve the owning module information from DWARF in the synthesized AST"
This reverts commit 4354dfbdf5 while investigating bot fallout.
2020-04-01 18:58:11 -07:00
Adrian Prantl 4354dfbdf5 Preserve the owning module information from DWARF in the synthesized AST
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
sets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.

rdar://problem/59634380

Differential Revision: https://reviews.llvm.org/D75488
2020-04-01 17:46:02 -07:00
Pavel Labath e22f0dabcf [lldb/breakpad] Fix register resolution on arm
In breakpad, only x86 (and mips) registers have a leading '$' in their
names. Arm architectures use plain register names.

Previously, lldb was assuming all registers have a '$'. Fix the code to
match the (unfortunately, inconsistent) reality.
2020-03-26 13:51:27 +01:00
Pavel Labath c72675394a [lldb] add lit.local.cfg for breakpad tests
The reason is to add .yaml as a valid test suffix. The test folder
contains one yaml file, which wasn't being run because of that.

Unsurprisingly the test fails, but this was not because the underlying
functionality was broken, but rather because the test was setup
incorrectly (most likely due to overly aggressive simplification of the
test data on my part).

Therefore this patch also tweaks the test inputs in order to test what
they are supposed to test, and also updates some other breakpad tests
(because they depend on the same inputs as this one) to be more
realistic -- specifically it avoids putting symbols to the first page of
the module, as that's where normally the COFF header would reside.
2020-03-25 17:00:46 +01:00
Jan Kratochvil 3481062bc6 [lldb] [testsuite] Enable forgotten -gsplit-dwarf for 2 testfiles
D63643 added these testfiles but some of the %t4dwo and %t5dwo builds
are the same as corresponding %t4 and %t5 builds. Fortunately the
testcases do PASS.

After just adding -gsplit-dwarf these both skeleton files:
  tools/lldb/test/SymbolFile/DWARF/Output/debug-types-expressions.test.tmp4dwo
  tools/lldb/test/SymbolFile/DWARF/Output/debug-types-expressions.test.tmp5dwo

were referencing to this one non-skeleton file:
  tools/lldb/test/SymbolFile/DWARF/debug-types-expressions.dwo

Surprisingly it does not affect the other test debug-types-basic.test
probably because it compiles to .o and then links it. While
debug-types-expressions.test compiles directly to an executable.

So fixed that while keeping the direct executable compilation.

Differential Revision: https://reviews.llvm.org/D76316
2020-03-18 15:49:24 +01:00
Pavel Labath c5ff3df839 [lldb] Hardcode target in dwo-type-in-main-file.s test 2020-03-16 13:25:10 +01:00
Pavel Labath 5abfa3226d [lldb/DWARF] Fix crash when a dwo compile unit refers to a non-dwo type
In this case dwo_num can be None => stop assuming it can't.
2020-03-16 12:12:59 +01:00
Pavel Labath eefbff0082 [lldb] s/CHECK-NEXT/CHECK-DAG in dwp-debug-types.s
These can come out nondeterministically for two reasons:
- sorting based on ConstStringified pointer values
- different relative speeds of the indexing threads

Making these nondeterministic without incurring performance penalties is
hard, so I just make the test expect them in any order (the order is not
important in this test anyway.
2020-02-25 10:04:09 +01:00
Pavel Labath c9c09ef836 [lldb/DWARF] Fix dwp search path in the separate-debug-file case
The convention is that the dwp file name is derived from the name of the
file holding the executable code, even if the linked portion of the
debug info is elsewhere (objcopy --only-keep-debug).
2020-02-24 17:01:15 +01:00
Pavel Labath be3b448c2e [lldb/test] simplify basic-elf.yaml
Explicit dynsym/dynstr sections were added in a6370d5 to compensate for
a yaml2obj change D74764. This test doesn't need those sections, so
instead I just delete the explicit section blocks, and also the
"DynamicSymbols" block, which triggers their implicit generation.
2020-02-24 09:02:18 +01:00
Pavel Labath 0f7cfb2543 [lldb/DWARF] Don't index dwp file multiple times
Summary:
When we added support for type units in dwo files, we changed the
"manual" dwarf index to index _all_ dwarf units in the dwo file instead
of just the split unit belonging to our skeleton unit. This was fine for
dwo files, as they contain only a single compile units and type units do
not have a split type unit which would point to them.

However, this does not work for dwp files because, these files do
contain multiple split compile units, and the current approach means
that each unit gets indexed multiple times (once for each split unit =>
n^2 complexity).

This patch teaches the manual dwarf index to treat dwp files specially.
Any type units in the dwp file added to the main list of compile units
and indexed with them in a single batch. Split compile units in dwp
files are still indexed as a part of their skeleton unit -- this is done
because we need the DW_AT_language attribute from the skeleton unit to
index them properly.

Handling of dwo files remains unchanged -- all units (type and skeleton)
are indexed when we reach the dwo file through the split unit.

Reviewers: clayborg, JDevlieghere, aprantl

Subscribers: arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74964
2020-02-24 08:50:51 +01:00
Georgii Rymar a6370d5798 [lldb][test] - Update basic-elf.yaml to fix build bot.
D74764 (https://reviews.llvm.org/rG31f2ad9c368d47721508cbd0d120d626f9041715)
changed the behavior of the yaml2obj. Now it assigns virtual addresses
for allocatable sections.

SymbolFile/Breakpad/symtab.test started to fail after this change:
(http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/5520/steps/test/logs/stdio)

Command Output (stderr):
--
/home/worker/lldb-x86_64-debian/lldb-x86_64-debian/llvm-project/lldb/test/Shell/SymbolFile/Breakpad/symtab.test:6:10: error: CHECK: expected string not found in input
# CHECK: Symtab, file = {{.*}}symtab.out, num_symbols = 5:
         ^
<stdin>:15:1: note: scanning from here
Symtab, file = /home/worker/lldb-x86_64-debian/lldb-x86_64-debian/build/tools/lldb/test/SymbolFile/Breakpad/Output/symtab.out, num_symbols = 6:
^
<stdin>:15:99: note: possible intended match here
Symtab, file = /home/worker/lldb-x86_64-debian/lldb-x86_64-debian/build/tools/lldb/test/SymbolFile/Breakpad/Output/symtab.out, num_symbols = 6:

For now I've updated the basic-elf.yaml so that now it produce the same layout as before D74764.
Breakpad/symtab.test should be updated it seems.
2020-02-22 16:09:24 +03:00
Fangrui Song e29065a105 [lldb][test] Fix sh_flags and sh_entsize of .debug_str.dwo
sh_flags: SHF_MERGE | SHF_STRINGS | SHF_EXCLUDE
sh_entsize: 1

Incorrect sh_flags or sh_entsize is an error after the assembler change made by D73999.
2020-02-21 18:51:05 -08:00
Fangrui Song ebee131259 [lldb][test] Fix sh_type of .debug_cu_index and .debug_tu_index
They do not have the SHF_EXCLUDE flag.
After D73999, MC errors `changed section type for .debug_cu_index, expected: 0x0`
2020-02-21 17:38:39 -08:00
Pavel Labath de8793b918 [lldb/DWARF] Add support for type units in dwp files
all that was needed was to teach lldb's DWARF context about the
debug_tu_index section.
2020-02-21 16:01:17 +01:00
Pavel Labath 8131cb6e18 [lldb/DWARF] Add support for location lists in package files
The only thing needed was to account for the offset from the
debug_cu_index section when searching for the location list.

This patch also fixes a bug in the Module::ParseAllDebugSymbols
function, which meant that we would only parse the variables of the
first compile unit in the module. This function is only used from
lldb-test, so this does not fix any real issue, besides preventing me
from writing a test for this patch.
2020-02-19 14:33:58 +01:00
Raphael Isemann 785df61680 [lldb] Let TypeSystemClang::GetDisplayTypeName remove anonymous and inline namespaces.
Summary:
Currently when printing data types we include implicit scopes such as inline namespaces or anonymous namespaces.
This leads to command output like this (for `std::set<X>` with X being in an anonymous namespace):

```
(lldb) print my_set
(std::__1::set<(anonymous namespace)::X, std::__1::less<(anonymous namespace)::X>, std::__1::allocator<(anonymous namespace)::X> >) $0 = size=0 {}
```

This patch removes all the implicit scopes when printing type names in TypeSystemClang::GetDisplayTypeName
so that our output now looks like this:

```
(lldb) print my_set
(std::set<X, std::less<X>, std::allocator<X> >) $0 = size=0 {}
```

As previously GetDisplayTypeName and GetTypeName had the same output we actually often used the
two as if they are the same method (they were in fact using the same implementation), so this patch also
fixes the places where we actually want the display type name and not the actual type name.

Note that this doesn't touch the `GetTypeName` class that for example the data formatters use, so this patch
is only changes the way we display types to the user. The full type name can also still be found when passing
'-R' to see the raw output of a variable in case someone is somehow interested in that.

Partly fixes rdar://problem/59292534

Reviewers: shafik, jingham

Reviewed By: shafik

Subscribers: christof, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74478
2020-02-19 10:30:11 +01:00
Pavel Labath 00539d8b64 [lldb/DWARF] Support the debug_str_offsets section in dwp files
Summary:
In dwp files a constant (from the debug_cu_index section) needs to be
added to each reference into the debug_str_offsets section.

I've tried to implement this to roughly match the llvm flow: I've
changed the DWARFormValue to stop resolving the indirect string
references directly -- instead, it calls into DWARFUnit, which resolves
this for it (similar to how it already resolves indirect range and
location list references). I've also done a small refactor of the string
offset base computation code in DWARFUnit in order to make it easier to
access the debug_cu_index base offset.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D74723
2020-02-18 11:02:34 +01:00
Pavel Labath 67f63f3f7c [lldb/DWARF] Re-enable basic dwp support
Summary:
This patch removes the bitrotted SymbolFileDWARF(Dwo)Dwp classes, and
replaces them with dwp support implemented directly inside
SymbolFileDWARFDwo, in a manner mirroring the implementation in llvm.
This patch does:
- add support for the .debug_cu_index section to our DWARFContext
- adds a llvm::DWARFUnitIndex argument to the DWARFUnit constructors.
  This argument is used to look up the offsets of the debug_info and
  debug_abbrev contributions in the sections of the dwp file.
- makes sure the creation of the DebugInfo object as well as the initial
  discovery of DWARFUnits is thread-safe, as we can now call this
  concurrently when doing parallel indexing.

This patch does not:
- use the DWARFUnitIndex to search for other kinds of contributions
  (debug_loc, debug_ranges, etc.). This means that units which reference
  these sections will not work correctly. These will be handled by
  follow-up patches, but even the present level of support is sufficient
  to enable basic functionality.
- Make the llvm::DWARFContext thread-safe. Right now, it just avoids this
  problem by ensuring everything is initialized ahead of time. However,
  this is something we will run into more often as we try to use more of
  llvm, and so I plan to start looking into our options here.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: mgorny, mgrang, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73783
2020-02-17 14:10:36 +01:00
Ted Woodward cecc185166 Add REQUIRES: x86 so this won't be run if x86 is not available. 2020-02-13 11:17:27 -06:00
Vedant Kumar 14135f50a0 [lldb/Value] Avoid reading more data than the host has available
Value::GetValueByteSize() reports the size of a Value as the size of its
underlying CompilerType. However, a host buffer that backs a Value may
be smaller than GetValueByteSize().

This situation arises when the host is only able to partially evaluate a
Value, e.g. because the expression contains DW_OP_piece.

The cleanest fix I've found to this problem is Greg's suggestion, which
is to resize the Value if (after evaluating an expression) it's found to
be too small. I've tried several alternatives which all (in one way or
the other) tried to teach the Value/ValueObjectChild system not to read
past the end of a host buffer, but this was flaky and impractical as it
isn't easy to figure out the host buffer's size (Value::GetScalar() can
point to somewhere /inside/ a host buffer, but you need to walk up the
ValueObject hierarchy to try and find its size).

This fixes an ASan error in lldb seen when debugging a clang binary.
I've added a regression test in test/functionalities/optimized_code. The
point of that test is not specifically to check that DW_OP_piece is
handled a particular way, but rather to check that lldb doesn't crash on
an input that it used to crash on.

Testing: check-lldb, and running the added tests using a sanitized lldb

--

Thanks to Jim for pointing out that an earlier version of this patch,
which simply changed the definition of Value::GetValueByteSize(), would
interact poorly with the ValueObject machinery.

Thanks also to Pavel who suggested a neat way to test this change
(which, incidentally, caught another ASan issue still present in the
original version of this patch).

rdar://58665925

Differential Revision: https://reviews.llvm.org/D73148
2020-01-31 16:33:12 -08:00
Jonas Devlieghere 457a6d49d5 [lldb/Reproducers] Fix typo in CMake so we actually replay.
The CMakeLists.txt had a typo which meant that check-lldb-repro was
capturing twice instead of capturing and then replaying. This also
uncovered a missing import in lldb-repro.py. This patch fixes both
issues.
2020-01-30 15:51:29 -08:00
Pavel Labath d8de349951 Revert "[lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)"
This reverts commit 1b12766883 because of
breaking the mac test suite.

I'm not certain this is the cause because of a concurrent build breakage
which masked this problem, but the failure messages are related to
symbol lookup, which makes this very likely.
2020-01-28 13:46:43 +01:00
Jaroslav Sevcik 1b12766883 [lldb/DWARF] Only match mangled name in full-name function lookup (with accelerators)
Summary:
In the spirit of https://reviews.llvm.org/D70846, we only return functions with matching mangled name from Apple/DebugNamesDWARFIndex::GetFunction if eFunctionNameTypeFull is requested.

This speeds up lookup in the presence of large amount of class methods of the same name (a typical examples would be constructors of templates with many instantiations or overloaded operators).

Reviewers: labath

Reviewed By: labath

Subscribers: aprantl, arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73191
2020-01-28 12:16:02 +01:00
Jonas Devlieghere 794b8a0329 [lldb] s/lldb/%lldb in another test
As explained in Pavel's previous commit message: %lldb is the proper
substitution. Using "lldb" can cause us to execute the system lldb
instead of the one we are testing. This happens at least in standalone
builds.
2020-01-23 11:17:24 -08:00
Pavel Labath 06e73f071a [lldb/DWARF] Change how we construct a llvm::DWARFContext
Summary:
The goal of this patch is two-fold. First, it fixes a use-after-free in
the construction of the llvm DWARFContext. This happened because the
construction code was throwing away the lldb DataExtractors it got while
reading the sections (unlike their llvm counterparts, these are also
responsible for memory ownership). In most cases this did not matter,
because the sections are just slices of the mmapped file data. But this
isn't the case for compressed elf sections, in which case the section is
decompressed into a heap buffer. A similar thing also happen with object
files which are loaded from process memory.

The second goal is to make it explicit which sections go into the llvm
DWARFContext -- any access to the sections through both DWARF parsers
carries a risk of parsing things twice, so it's better if this is a
conscious decision. Also, this avoids loading completely irrelevant
sections (e.g. .text). At present, the only section that needs to be
present in the llvm DWARFContext is the debug_line_str. Using it through
both APIs is not a problem, as there is no parsing involved.

The first goal is achieved by loading the sections through the existing
lldb DWARFContext APIs, which already do the caching. The second by
explicitly enumerating the sections we wish to load.

Reviewers: JDevlieghere, aprantl

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D72917
2020-01-20 11:45:53 +01:00
Adrian Prantl ec9a3cccd4 Update testcase for LLVM IR change (sysroot) 2020-01-17 11:04:55 -08:00
Pavel Labath ee05138515 [lldb/test] Revert changes to debug-names-compressed.cpp
With the changes in 15a6df52ef, the test is failing in some
configurations. Reverting while I investigate
2020-01-16 18:56:26 +01:00
Pavel Labath 15a6df52ef [lldb/DWARF/test] Freshen up debug_names tests
These tests used "clang -mllvm -accel-tables=Dwarf" as a way to
guarantee that clang will emit the debug_names table. Unfortunately,
a change it clang made that insufficient (-gpubnames is required now
too), which rendered these tests ineffective. Since lldb automatically
falls back to the manual index, the tests didn't fail and this change
went largely unnoticed.

This patch updates the tests to really use debug_names (-gdwarf-5
-gpubnames) is the combination that works now, and it adds additional
checks to ensure the section is actually emitted.

Fortunately, no regressions crept in while these tests were disabled.
2020-01-16 16:25:49 +01:00
Pavel Labath 4b5bc38802 [lldb/DWARF] Move location list sections into DWARFContext
These are the last sections not managed by the DWARFContext object. I
also introduce separate SectionType enums for dwo section variants, as
this is necessary for proper handling of single-file split dwarf.
2020-01-14 15:19:29 +01:00
Levon Ter-Grigoryan a705cf1acb Expression eval lookup speedup by not returning methods in ManualDWARFIndex::GetFunctions
Summary:
This change is connected with
https://reviews.llvm.org/D69843

In large codebases, we sometimes see Module::FindFunctions (when called from
ClangExpressionDeclMap::FindExternalVisibleDecls) returning huge amounts of
functions.

In current fix I trying to return only function_fullnames from ManualDWARFIndex::GetFunctions when eFunctionNameTypeFull is passed as argument.

Reviewers: labath, jarin, aprantl

Reviewed By: labath

Subscribers: shafik, clayborg, teemperor, arphaman, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70846
2020-01-14 14:59:56 +01:00
Jan Kratochvil bf7225888a [lldb] Fix lookup of symbols with the same address range but different binding
This fixes a failing testcase on Fedora 30 x86_64 (regression Fedora 29->30):

PASS:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
  * frame #0: 0x00007ffff7aa6e75 libc.so.6`__GI_raise + 325
    frame #1: 0x00007ffff7a91895 libc.so.6`__GI_abort + 295
    frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
    frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
    frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
    frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
    frame #6: 0x00007ffff7a92f33 libc.so.6`__libc_start_main + 243
    frame #7: 0x000000000040106e a.out`_start + 46

vs.

FAIL - unrecognized abort() function:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
  * frame #0: 0x00007ffff7aa6e75 libc.so.6`.annobin_raise.c + 325
    frame #1: 0x00007ffff7a91895 libc.so.6`.annobin_loadmsgcat.c_end.unlikely + 295
    frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
    frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
    frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
    frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
    frame #6: 0x00007ffff7a92f33 libc.so.6`.annobin_libc_start.c + 243
    frame #7: 0x000000000040106e a.out`.annobin_init.c.hot + 46

The extra ELF symbols are there due to Annobin (I did not investigate why this
problem happened specifically since F-30 and not since F-28).

It is due to:

Symbol table '.dynsym' contains 2361 entries:
Valu e          Size Type   Bind   Vis     Name
0000000000022769   5 FUNC   LOCAL  DEFAULT _nl_load_domain.cold
000000000002276e   0 NOTYPE LOCAL  HIDDEN  .annobin_abort.c.unlikely
...
000000000002276e   0 NOTYPE LOCAL  HIDDEN  .annobin_loadmsgcat.c_end.unlikely
...
000000000002276e   0 NOTYPE LOCAL  HIDDEN  .annobin_textdomain.c_end.unlikely
000000000002276e 548 FUNC   GLOBAL DEFAULT abort
000000000002276e 548 FUNC   GLOBAL DEFAULT abort@@GLIBC_2.2.5
000000000002276e 548 FUNC   LOCAL  DEFAULT __GI_abort
0000000000022992   0 NOTYPE LOCAL  HIDDEN  .annobin_abort.c_end.unlikely

GDB has some more complicated preferences between overlapping and/or sharing
address symbols, I have made here so far the most simple fix for this case.

Differential revision: https://reviews.llvm.org/D63540
2020-01-13 12:05:26 +01:00
Pavel Labath cd5da94d80 [lldb/DWARF] Fix mixed v4+v5 location lists
Summary:
Our code was expecting that a single (symbol) file contains only one
kind of location lists. This is not correct (on non-apple platforms, at
least) as a file can compile units with different dwarf versions.

This patch moves the deteremination of location list flavour down to the
compile unit level, fixing this problem. I have also tried to rougly
align the code with the llvm DWARFUnit. Fully matching the API is not
possible because of how lldb's DWARFExpression lives separately from the
rest of the DWARF code, but this is at least a step in the right
direction.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71751
2020-01-09 13:19:29 +01:00
Pavel Labath 46f02fc922 [lldb/DWARF] Fix hostname-stripping logic
This bit of code is trying to strip everything up to the first colon
from all debug info paths, as dwarf2 recommends this syntax for storing
the compilation host name. However, this code was too eager, and it
ended up stripping the entire compilation directory, if it did not
contain a forward slash (or a "x:\").

Normally this does not matter, as all absolute paths will contain one of
these patterns, but this does not have to be the case in case the debug
info is produced by "clang -fdebug-compilation-dir", which can end up
producing a relative compilation directory with no slashes (this is one
of the techniques for producing "relocatable" debug info).
2019-12-23 14:54:22 +01:00
Jonas Devlieghere 3fa39c3a79 [lldb/test] Update !DIModule for isysroot rename
The isysroot field in DIModule was renamed to sysroot but the test in
LLDB wasn't updated. This fixes that.
2019-12-20 21:11:50 -08:00
Johannes Altmanninger 04329dbfa6 [lldb] Fix test using lld on non-linux systems 2019-12-20 13:27:40 +01:00
Johannes Altmanninger 92211bf0f1 [LLDB] Fix address computation for inline function
Summary:
Fixes PR41237 - SIGSEGV on call expression evaluation when debugging clang

When linking multiple compilation units that define the same functions,
the functions is merged but their debug info is not. This ignores debug
info entries for functions in a non-executable sections; those are
functions that were definitely dropped by the linker.

Reviewers: spyffe, clayborg, jasonmolenda

Reviewed By: clayborg

Subscribers: labath, aprantl, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71487
2019-12-20 09:04:45 +01:00
Pavel Labath 6ce1a897b6 [lldb/DWARF] Fix v5 location lists for dwo files
Dwo files don't have a DW_AT_loclists_base -- set one explicitly. Also,
make sure we use the correct location list flavour for v5.
2019-12-12 15:28:11 +01:00
Pavel Labath d6d36ae4a0 [lldb] "See through" atomic types in ClangASTContext
Summary:
This enables us to display the contents of atomic structs. Calling the
removal of _Atomic "desugaring" is not fully correct as it does more
than remove sugar, but it is the right thing to do for most of the
things that we care about. We can change this back once we decide to
support atomic types more comprehensively.

Reviewers: teemperor, shafik

Subscribers: jfb, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71262
2019-12-12 11:45:03 +01:00
Pavel Labath c8b74ee264 [lldb/DWARF] Add support for DW_AT_loclists_base&DW_FORM_loclistx
Summary:
This adds support for DWARF5 location lists which are specified
indirectly, via an index into the debug_loclists offset table. This
includes parsing the DW_AT_loclists_base attribute which determines the
location of this offset table, and support for new form DW_FORM_loclistx
which is used in conjuction with DW_AT_location to refer to the location
lists in this way.

The code uses the llvm class to parse the offset information, and I've
also tried to structure it similarly to how the relevant llvm
functionality works.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71268
2019-12-11 11:06:17 +01:00
Pavel Labath 773b849c10 [lldb/DWARF] Switch to llvm location list parser
Summary:
This patch deletes the lldb location list parser and teaches the
DWARFExpression class to use the parser in llvm instead. I have
centralized all the places doing the parsing into a single
GetLocationExpression function.

In theory the the actual location list parsing should be covered by llvm
tests, and this glue code by our existing location list tests, but since
we don't have that many location list tests, I've tried to extend the
coverage a bit by adding some explicit dwarf5 loclist handling and a
test of the dumping code.

For DWARF4 location lists this should be NFC (modulo small differences
in error handling which should only show up on invalid inputs). In case
of DWARF5, this fixes various missing bits of functionality, most
notably, the lack of support for DW_LLE_offset_pair.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: lldb-commits, dblaikie

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71003
2019-12-09 13:39:10 +01:00
Pavel Labath 329008fdf1 [lldb] Improve/fix base address selection in location lists
Summary:
Lldb support base address selection entries in location lists was broken
for a long time. This wasn't noticed until llvm started producing these
kinds of entries more frequently with r374600.

In r374769, I made a quick patch which added sufficient support for them
to get the test suite to pass. However, I did not fully understand how
this code operates, and so the fix was not complete. Specifically, what
was lacking was the ability to handle modules which were not loaded at
their preferred load address (for instance, due to ASLR).

Now that I better understand how this code works, I've come to the
conclusion that the current setup does not provide enough information
to correctly process these entries. In the current setup the location
lists were parameterized by two addresses:
- the distance of the function start from the start of the compile unit.
  The purpose of this was to make the location ranges relative to the
  start of the function.
- the actual address where the function was loaded at. With this the
  function-start-relative ranges can be translated to actual memory
  locations.

The reason for the two values, instead of just one (the load bias) is (I
think) MachO, where the debug info in the object files will appear to be
relative to the address zero, but the actual code it refers to
can be moved and reordered by the linker. This means that the location
lists need to be "linked" to reflect the locations in the actual linked
file.

These two bits of information were enough to correctly process location
lists which do not contain base address selection entries (and so all
entries are relative to the CU base). However, they don't work with
them because, in theory two base address can be completely unrelated (as
can happen for instace with hot/cold function splitting, where the
linker can reorder the two pars arbitrarily).

To fix that, I split the first parameter into two:
- the compile unit base address
- the function start address, as is known in the object file

The new algorithm becomes:
- the location lists are processed as they were meant to be processed.
  The CU base address is used as the initial base address value. Base
  address selection entries can set a new base.
- the difference between the "file" and "load" function start addresses
  is used to compute the load bias. This value is added to the final
  ranges to get the actual memory location.

This algorithm is correct for non-MachO debug info, as there the
location lists correctly describe the code in the final executable, and
the dynamic linker can just move the entire module, not pieces of it. It
will also be correct for MachO if the static linker preserves relative
positions of the various parts of the location lists -- I don't know
whether it actually does that, but judging by the lack of base address
selection support in dsymutil and lldb, this isn't something that has
come up in the past.

I add a test case which simulates the ASLR scenario and demonstrates
that base address selection entries now work correctly here.

Reviewers: JDevlieghere, aprantl, clayborg

Subscribers: dblaikie, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70532
2019-12-09 13:39:08 +01:00
Raphael Isemann d0fb7a478d [lldb] Support for DWARF-5 atomic types
Summary:
This patch adds support for atomic types (DW_TAG_atomic_type) to LLDB. It's mostly just filling out all the switch-statements that didn't implement Atomic case with the usual boilerplate.

Thanks Pavel for writing the test case.

Reviewers: labath, aprantl, shafik

Reviewed By: labath

Subscribers: jfb, abidh, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D71183
2019-12-09 10:46:26 +01:00