Commit Graph

104 Commits

Author SHA1 Message Date
Jake Egan d24e721deb [AIX] Disable tests failing due to lack of 64-bit XCOFF object file support
The following tests are failing because 64-bit XCOFF object files are not currently supported on AIX. This patch disables these tests on AIX for now.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D111887
2021-10-18 13:08:22 -04:00
Reid Kleckner 89b57061f7 Move TargetRegistry.(h|cpp) from Support to MC
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.

This allows us to ensure that Support doesn't have includes from MC/*.

Differential Revision: https://reviews.llvm.org/D111454
2021-10-08 14:51:48 -07:00
Jake Egan 8037481cb2 [AIX] Disable tests failing due to missing DWARF sections
The following tests are failing due to missing DWARF sections. This patch sets these tests as XFAIL/DISABLED on AIX until a more permanent solution is implemented.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D111336
2021-10-08 12:06:38 -04:00
Alexander Yermolovich 779d24e151 [DWARF] Find offset of attribute.
This is used by BOLT to do patching of DebugInfo section, and Line Table. Directly by using find, and through getAttrFieldOffsetForUnit.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D107874
2021-09-01 11:49:55 -07:00
David Blaikie 2af4db7d5c Migrate DWARFVerifier tests to lit-based yaml instead of gtest with embedded yaml
Improves maintainability (edit/modify the tests without recompiling) and
error messages (previously the failure would be a gtest failure
mentioning nothing of the input or desired text) and the option to
improve tests with more checks.

(maybe these tests shouldn't all be in separate files - we could
probably have DWARF yaml that contains multiple errors while still being
fairly maintainable - the various invalid offsets (ref_addr, rnglists,
ranges, etc) could probably be all in one test, but for the simple sake
of the migration I just did the mechanical thing here)
2021-08-13 19:09:41 -07:00
Alexander Yermolovich 5a865b0b1e [DWARF] Don't process .debug_info relocations for DWO Context
When we build with split dwarf in single mode the .o files that contain both "normal" debug sections and dwo sections, along with relocaiton sections for "normal" debug sections.
When we create DWARF context in DWARFObjInMemory we process relocations and store them in the map for .debug_info, etc section.
For DWO Context we also do it for non dwo dwarf sections. Which I believe is not necessary. This leads to a lot of memory being wasted. We observed 70GB extra memory being used.

I went with context sensitive approach, flag is passed in. I am not sure if it's always safe not to process relocations for regular debug sections if Obj contains .dwo sections.
If it is alternatvie might be just to scan, in constructor, sections and if there are .dwo sections not to process regular debug ones.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D106624
2021-08-02 10:41:47 -07:00
Nigel Perks 251fe986af [Test][DebugInfo] Check for backend object emission support.
The XCore backend does not support object emission. Several tests fail for this
reason when XCore is the default target. See staging buildbot builder:
clang-xcore-ubuntu-20-x64.

So check for backend object emission before running the tests requiring it.

Incorporate isConfigurationSupported functionality in isObjectEmissionSupported,
to avoid calling them both in the same tests.

Differential Revision: https://reviews.llvm.org/D98400
2021-03-18 09:51:00 +00:00
Xing GUO 1d01fc100b [Test] Simplify DWARF test cases. NFC.
The Length, AbbrOffset and Values fields of the debug_info section are
optional. This patch helps remove them and simplify test cases.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D86857
2020-08-31 14:03:48 +08:00
Xing GUO 12e832cbcb [DWARFYAML] Make the debug_abbrev_offset field optional.
This patch helps make the debug_abbrev_offset field optional. We don't
need to calculate the value of this field in the future.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86614
2020-08-29 14:54:52 +08:00
Xing GUO 8daa3264a3 [DWARFYAML] Make the unit_length and header_length fields optional.
This patch makes the unit_length and header_length fields of line tables
optional. yaml2obj is able to infer them for us.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D86590
2020-08-26 20:35:10 +08:00
Xing GUO 1dc57ada0c [DWARFYAML] Make the 'Attributes' field optional.
This patch makes the 'Attributes' field optional. We don't need to
explicitly specify the 'Attributes' field in the future.

Reviewed By: jhenderson, grimar

Differential Revision: https://reviews.llvm.org/D86537
2020-08-25 22:37:43 +08:00
Xing GUO f5643dc3dc Recommit: [DWARFYAML] Add support for referencing different abbrev tables.
The original commit (7ff0ace96db9164dcde232c36cab6519ea4fce8) was causing
build failure and was reverted in 6d242a7326

==================== Original Commit Message ====================
This patch adds support for referencing different abbrev tables. We use
'ID' to distinguish abbrev tables and use 'AbbrevTableID' to explicitly
assign an abbrev table to compilation units.

The syntax is:
```
debug_abbrev:
  - ID: 0
    Table:
      ...
  - ID: 1
    Table:
      ...
debug_info:
  - ...
    AbbrevTableID: 1 ## Reference the second abbrev table.
  - ...
    AbbrevTableID: 0 ## Reference the first abbrev table.
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83116
2020-08-21 19:02:10 +08:00
Xing GUO 6d242a7326 Revert "[DWARFYAML] Add support for referencing different abbrev tables."
This reverts commit f7ff0ace96.

This change is causing build failure.

http://lab.llvm.org:8011/builders/clang-cmake-armv7-global-isel/builds/10400
2020-08-21 12:15:54 +08:00
Xing GUO f7ff0ace96 [DWARFYAML] Add support for referencing different abbrev tables.
This patch adds support for referencing different abbrev tables. We use
'ID' to distinguish abbrev tables and use 'AbbrevTableID' to explicitly
assign an abbrev table to compilation units.

The syntax is:
```
debug_abbrev:
  - ID: 0
    Table:
      ...
  - ID: 1
    Table:
      ...
debug_info:
  - ...
    AbbrevTableID: 1 ## Reference the second abbrev table.
  - ...
    AbbrevTableID: 0 ## Reference the first abbrev table.
```

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D83116
2020-08-21 11:44:25 +08:00
Xing GUO 290e399f96 [DWARFYAML] Add support for emitting multiple abbrev tables.
This patch adds support for emitting multiple abbrev tables. Currently,
compilation units will always reference the first abbrev table.

Reviewed By: jhenderson, labath

Differential Revision: https://reviews.llvm.org/D86194
2020-08-21 10:12:08 +08:00
Xing GUO 92874d2866 [DWARFYAML] Refactor emitDebugInfo() to make the length be inferred.
This patch refactors `emitDebugInfo()` to make the length field be
inferred from its content. Besides, the `Visitor` class is removed in
this patch. The original `Visitor` class helps us determine an
appropriate length and emit the .debug_info section. These two
processes can be merged into one process. Besides, the length field
should be inferred when it's missing rather than when it's zero.

Reviewed By: jhenderson, labath

Differential Revision: https://reviews.llvm.org/D84008
2020-07-23 23:00:19 +08:00
Xing GUO 8632931787 [DWARFYAML] Make the length field of compilation units optional. NFC.
This patch makes the length field of compilation units optional (0 by
default).
2020-07-22 12:16:19 +08:00
Xing GUO fe08ab542b [DWARFYAML][debug_info] Replace 'InitialLength' with 'Format' and 'Length'.
'InitialLength' is replaced with 'Format' (DWARF32 by default) and 'Length' in this patch.
Besides, test cases for DWARFv4 and DWARFv5, DWARF32 and DWARF64 is
added.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D82622
2020-06-30 16:28:39 +08:00
Xing GUO 0431e4bcb2 Recommit "[DWARFYAML][debug_line] Replace `InitialLength` with `Format` and `Length`."
This recommits fcc0c186e9
2020-06-13 23:39:11 +08:00
Xing GUO 67b4afc41a [DWARFYAML] Rename function names to match the coding style. NFC. 2020-06-08 17:31:02 +08:00
Jonas Devlieghere 3e4a16d2cb [llvm/DebugInfo] Fix invalid verifier error for DWARF5
We unconditionally compared the DW_AT_ranges offset to the length of the
.debug_ranges section. For DWARF5 we should look at the debug_rnglists
section instead.

Differential revision: https://reviews.llvm.org/D78971
2020-04-28 10:25:34 -07:00
Jonas Devlieghere bbaa639ba9 [llvm/DebugInfo] Print DW_AT_ranges offset as part of verifier error.
Print the DW_AT_ranges offset as part of the verifier error, like we do
for the DW_AT_stmt_list offset.
2020-04-27 16:45:17 -07:00
Igor Kudrin af11c556db [DebugInfo] Fix reading DWARFv5 type units in DWP.
In DWARFv5, type units are stored in .debug_info sections, along with
compilation units, and they are distinguished by the unit_type field
in the header, not by the name of the section. It is impossible to
associate the correct index section of a DWP file with the unit before
the unit's header is read. This patch fixes reading DWARFv5 type units
by parsing the header first and then applying the index entry according
to the actual unit type.

Differential Revision: https://reviews.llvm.org/D77552
2020-04-08 12:50:58 +07:00
Alexey Lapshin f943443e65 [Debuginfo][NFC] Unify error reporting routines inside DebugInfoDWARF.
Summary:
Error reporting in DebugInfoDWARF library currently done in three ways :

1. Direct calls to WithColor::error()/WithColor::warning()
2. ErrorPolicy defaultErrorHandler(Error E);
3. void dumpWarning(Error Warning);

additionally, other locations could have more variations:

lld/ELF/SyntheticSection.cpp
    if (Error e = cu->tryExtractDIEsIfNeeded(false)) {
      error(toString(sec) + ": " + toString(std::move(e)));

DebugInfo/DWARF/DWARFUnit.cpp
  if (Error e = tryExtractDIEsIfNeeded(CUDieOnly))
    WithColor::error() << toString(std::move(e));

Thus error reporting could look inconsistent. To have a consistent error
messages it is necessary to have a possibility to redefine error
reporting functions. This patch creates two handlers and allows to
redefine them. It also patches all places inside DebugInfoDWARF
to use these handlers.

The intention is always to use following handlers for error reporting
purposes inside DebugInfoDWARF:

DebugInfo/DWARF/DWARFContext.h

std::function<void(Error E)> RecoverableErrorHandler = WithColor::defaultErrorHandler;
std::function<void(Error E)> WarningHandler = WithColor::defaultWarningHandler;

This is last patch from series of patches: D74481, D74635, D75118.

Reviewers: jhenderson, dblaikie, probinson, aprantl, JDevlieghere

Reviewed By: jhenderson

Subscribers: grimar, hiraditya, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D74308
2020-02-27 18:32:40 +03:00
Alexey Lapshin 949134e2fe [DebugInfo][NFC] Remove handler with ErrorPolicy from DWARFContext.
Summary:
Current LLVM code base does not use error handler with ErrorPolicy.
This patch removes ErrorPolicy from DWARFContext.

This patch is extracted from the D74308.

Reviewers: jhenderson, dblaikie, grimar, aprantl, JDevlieghere

Reviewed By: grimar

Subscribers: hiraditya, llvm-commits

Tags: #llvm, #debug-info

Differential Revision: https://reviews.llvm.org/D75118
2020-02-27 00:42:37 +03:00
Fangrui Song a55daa1461 [MC] De-capitalize some MCStreamer::Emit* functions 2020-02-14 19:11:53 -08:00
Igor Kudrin bc48588f76 Reland [DWARF] Add a unit test for DWARFUnit::getLength().
This is a follow-up of rL369529, where the return value of
DWARFUnit::getLength() was changed from uint32_t to uint64_t.
The test checks that a unit header with Length > 4G can be successfully
parsed and the value of the Length field is not truncated.

Differential Revision: https://reviews.llvm.org/D67276

llvm-svn: 371510
2019-09-10 11:54:32 +00:00
Igor Kudrin c27af19280 Revert "[DWARF] Add a unit test for DWARFUnit::getLength()" because it broke ASAN bot.
llvm-svn: 371505
2019-09-10 10:17:48 +00:00
Igor Kudrin 3565c6b15c [DWARF] Add a unit test for DWARFUnit::getLength().
This is a follow-up of rL369529, where the return value of
DWARFUnit::getLength() was changed from uint32_t to uint64_t.
The test checks that a unit header with Length > 4G can be successfully
parsed and the value of the Length field is not truncated.

Differential Revision: https://reviews.llvm.org/D67276

llvm-svn: 371499
2019-09-10 09:03:24 +00:00
David Blaikie 90146cd8b9 DebugInfo/DWARF: Normalize DWARFObject members on the DWARF spec section names
Some of these names were abbreviated, some were not, some pluralised,
some not. Made the API difficult to use - since it's an exact 1:1
mapping to the DWARF sections - use those names (changing underscore
separation for camel casing).

llvm-svn: 368189
2019-08-07 17:18:11 +00:00
Jason Liu 552fda839a Fix DWARF DebugInfo unit test errors when cross-compiling
Summary:
When building with a Default Target set we can experience issues
in the DWARF DebugInfo unit tests because:

They assume we can generate object files for the host platform.
Some tests assume the endianess of the target we are generating
DWARF for and the host match.

This patch correct these issues by ensuring the tests which
generate objects in memory are run with respect to
LVM_DEFAULT_TARGET_TRIPLE and it's endianess.

We also make sure we don't use the hosts address size for line test
and split the triple util function in DwarfUtils into a version
that takes an address size and one that doesn't.

See also for discussion:
http://lists.llvm.org/pipermail/llvm-dev/2019-March/131212.html

Patch by: daltenty

Differential Revision: https://reviews.llvm.org/D62084

llvm-svn: 362454
2019-06-03 22:22:03 +00:00
Fangrui Song f56a436891 [DWARF] Fix DWARFVerifier::DieRangeInfo::contains
It didn't handle empty LHS correctly. If two ranges of LHS were
contiguous and jointly contained one range of RHS, it could also be incorrect.

DWARFAddressRange::contains can be removed and its tests can be merged into DWARFVerifier::DieRangeInfo::contains

llvm-svn: 358387
2019-04-15 10:02:36 +00:00
Fangrui Song b93de4cd26 [DWARF] Fix DWARFVerifier::DieRangeInfo::intersects
It was incorrect if RHS had more than 1 ranges and one of the ranges interacted with *this

llvm-svn: 358376
2019-04-15 08:30:10 +00:00
Jonas Devlieghere bb111152b7 [DWARFFormValue] Cleanup DWARFFormValue interface. (NFC)
DWARFFormValues can be created from a data extractor or by passing its
value directly. Until now this was done by member functions that
modified an existing object's internal state. This patch replaces a
subset of these methods with static method that return a new
DWARFFormValue.

llvm-svn: 354941
2019-02-27 00:58:09 +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
Jonas Devlieghere 7323259de8 [DebugInfo] Define base function on DWARFDie reverse iterators
This defines member function base on the specialization of
std::reverse_iterator for DWARFDie::iterator as required by C++
[reverse.iter.conv].

This fixes unit test DWARFDebugInfoTest.cpp under EXPENSIVE_CHECKS which
currently can't be built due to GNU C++ Library calling this member
function in debug mode.

This fixes https://llvm.org/PR38785

Patch by: Eugene Sharygin

Differential revision: https://reviews.llvm.org/D53792

llvm-svn: 345621
2018-10-30 18:25:28 +00:00
Pavel Labath 2f0881160c [DebugInfo] Reduce debug_str_offsets section size
Summary:
The accelerator tables use the debug_str section to store their strings.
However, they do not support the indirect method of access that is
available for the debug_info section (DW_FORM_strx et al.).

Currently our code is assuming that all strings can/will be referenced
indirectly, and puts all of them into the debug_str_offsets section.
This is generally true for regular (unsplit) dwarf, but in the DWO case,
most of the strings in the debug_str section will only be used from the
accelerator tables. Therefore the contents of the debug_str_offsets
section will be largely unused and bloating the main executable.

This patch rectifies this by teaching the DwarfStringPool to
differentiate between strings accessed directly and indirectly. When a
user inserts a string into the pool it has to declare whether that
string will be referenced directly or not. If at least one user requsts
indirect access, that string will be assigned an index ID and put into
debug_str_offsets table. Otherwise, the offset table is skipped.

This approach reduces the overall binary size (when compiled with
-gdwarf-5 -gsplit-dwarf) in my tests by about 2% (debug_str_offsets is
shrunk by 99%).

Reviewers: probinson, dblaikie, JDevlieghere

Subscribers: aprantl, mgrang, llvm-commits

Differential Revision: https://reviews.llvm.org/D49493

llvm-svn: 339122
2018-08-07 09:54:52 +00:00
Paul Robinson 143eaeab53 [DebugInfo/DWARF] [1/4] De-templatize DWARFUnitSection. NFC
This is patch 1 of 4 NFC refactorings to handle type units and compile
units more consistently and with less concern about the object-file
section that they came from.

Patch 1 replaces the templated DWARFUnitSection with a non-templated
version. That is, instead of being a SmallVector of pointers to a
specific unit kind, it is not a SmallVector of pointers to the base
class for both type and compile units.  Virtual methods are magic.

Differential Revision: https://reviews.llvm.org/D49741

llvm-svn: 338628
2018-08-01 20:43:47 +00:00
Jonas Devlieghere 3a04bea91a [DebugInfo] Have custom std::reverse_iterator<DWARFDie>
The DWARFDie is a lightweight utility wrapper that stores a pointer to a
compile unit and a debug info entry. Currently, its iterator (used for
walking over its children) stores a DWARFDie and returns a const
reference when dereferencing it.

When the iterator is modified (by incrementing or decrementing it), this
reference becomes invalid. This was happening when calling reverse on
it, because the std::reverse_iterator is keeping a temporary copy of the
iterator (see
https://en.cppreference.com/w/cpp/iterator/reverse_iterator for a good
illustration).

The relevant code in libcxx:

  reference operator*() const {_Iter __tmp = current; return *--__tmp;}

When dereferencing the reverse iterator, we decrement and return a
reference to a DWARFDie stored in the stack frame of this function,
resulting in UB at runtime.

This patch specifies the std::reverse_iterator for DWARFDie to do the
right thing.

Differential revision: https://reviews.llvm.org/D49679

llvm-svn: 338506
2018-08-01 10:24:17 +00:00
Pavel Labath 7bfa5d6544 dwarfgen: Add support for generating the debug_str_offsets section, take 3
Previous version of this patch failed on darwin targets because of
different handling of cross-debug-section relocations. This fixes the
tests to emit the DW_AT_str_offsets_base attribute correctly in both
cases. Since doing this is a non-trivial amount of code, and I'm going
to need it in more than one test, I've added a helper function to the
dwarfgen DIE class to do it.

Original commit message follows:

The motivation for this is D49493, where we'd like to test details of
debug_str_offsets behavior which is difficult to trigger from a
traditional test.

This adds the plubming necessary for dwarfgen to generate this section.
The more interesting changes are:
- I've moved emitStringOffsetsTableHeader function from DwarfFile to
  DwarfStringPool, so I can generate the section header more easily from
  the unit test.
- added a new addAttribute overload taking an MCExpr*. This is used to
  generate the DW_AT_str_offsets_base, which links a compile unit to the
  offset table.

I've also added a basic test for reading and writing DW_form_strx forms.

Reviewers: dblaikie, JDevlieghere, probinson

Subscribers: llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D49670

llvm-svn: 338031
2018-07-26 14:36:07 +00:00
Pavel Labath da3c4fb5fe Revert "dwarfgen: Add support for generating the debug_str_offsets section, take 2"
This reverts commit r337933. The build error is fixed but the test now
fails on the darwin buildbots. Investigating...

llvm-svn: 337935
2018-07-25 16:34:43 +00:00
Pavel Labath 78ab659bb4 dwarfgen: Add support for generating the debug_str_offsets section, take 2
This recommits r337910 after fixing an "ambiguous call to addAttribute"
error with some compilers (gcc circa 4.9 and MSVC). It seems that these
compilers will consider a "false -> pointer" conversion during overload
resolution. This creates ambiguity because one I added an overload which
takes a MCExpr * as an argument.

I fix this by making the new overload take MCExpr&, which avoids the
conversion. It also documents the fact that we expect a valid MCExpr
object.

Original commit message follows:

The motivation for this is D49493, where we'd like to test details of
debug_str_offsets behavior which is difficult to trigger from a
traditional test.

This adds the plubming necessary for dwarfgen to generate this section.
The more interesting changes are:
- I've moved emitStringOffsetsTableHeader function from DwarfFile to
  DwarfStringPool, so I can generate the section header more easily from
  the unit test.
- added a new addAttribute overload taking an MCExpr*. This is used to
  generate the DW_AT_str_offsets_base, which links a compile unit to the
  offset table.

I've also added a basic test for reading and writing DW_form_strx forms.

Reviewers: dblaikie, JDevlieghere, probinson

Subscribers: llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D49670

llvm-svn: 337933
2018-07-25 15:33:32 +00:00
Pavel Labath b4e17c29dd Revert "dwarfgen: Add support for generating the debug_str_offsets section"
This reverts commit r337910 as it's generating "ambiguous call to
addAttribute" errors on some bots.

Will resubmit once I get a chance to look into the problem.

llvm-svn: 337924
2018-07-25 12:52:30 +00:00
Pavel Labath 7a59e3bf37 dwarfgen: Add support for generating the debug_str_offsets section
Summary:
The motivation for this is D49493, where we'd like to test details of
debug_str_offsets behavior which is difficult to trigger from a
traditional test.

This adds the plubming necessary for dwarfgen to generate this section.
The more interesting changes are:
- I've moved emitStringOffsetsTableHeader function from DwarfFile to
  DwarfStringPool, so I can generate the section header more easily from
  the unit test.
- added a new addAttribute overload taking an MCExpr*. This is used to
  generate the DW_AT_str_offsets_base, which links a compile unit to the
  offset table.

I've also added a basic test for reading and writing DW_form_strx forms.

Reviewers: dblaikie, JDevlieghere, probinson

Subscribers: llvm-commits, aprantl

Differential Revision: https://reviews.llvm.org/D49670

llvm-svn: 337910
2018-07-25 11:55:59 +00:00
Jonas Devlieghere 3f27e57ade [DebugInfo] Make children iterator bidirectional
Make the DIE iterator bidirectional so we can move to the previous
sibling of a DIE.

Differential revision: https://reviews.llvm.org/D49173

llvm-svn: 336823
2018-07-11 17:11:11 +00:00
Nico Weber da750079fa IWYU for llvm-config.h, removals. Also see r331184.
llvm-svn: 331190
2018-04-30 15:26:01 +00:00
Jonas Devlieghere 5c709eda07 [ObjectYAML] Add ability for DWARFYAML to calculate DIE lengths
This patch adds the ability for the ObjectYAML DWARFEmitter to calculate
the lengths of DIEs. This is accomplished by creating a DIEFixupVisitor
class which traverses the DWARF DIEs to calculate and fix up the lengths
in the Compile Unit header.

The DIEFixupVisitor can be extended in the future to enable more complex
fix ups which will enable simplified YAML string representations.

This is also very useful when using the YAML format in unit tests
because you no longer need to know the length of the compile unit when
writing the YAML string.

Differential commandeered from Chris Bieneman (beanz)

Differential revision: https://reviews.llvm.org/D30666

llvm-svn: 330421
2018-04-20 12:33:49 +00:00
James Henderson 667026297d [DWARF] Don't attempt to parse line tables at invalid offsets
Whilst working on improvements to the error handling of the debug line
parsing code, I noticed that if an invalid offset were to be specified
in a call to getOrParseLineTable(), an entry in the LineTableMap would
still be created, even if the offset was not within the section range.
The immediate parsing attempt afterwards would fail (it would end up
getting a version of 0), and thereafter, any subsequent calls to
getOrParseLineTable or getLineTable would return the default-
constructed, invalid line table. In reality, we shouldn't even attempt
to parse this table, and we should always return a nullptr from these
two functions for this situation.

I have tested this via a unit test, which required some new framework
for unit testing debug line. My plan is to add quite a few more unit
tests for the new error reporting mechanism that will follow shortly,
hence the reason why the supporting code for the tests are written the
way they are - I intend to extend the DwarfGenerator class to support
generating debug line. At that point, I'll make sure that there are a
few positive test cases for this and the parsing code too.

Differential Revision: https://reviews.llvm.org/D44200

Reviewers: JDevlieghere, aprantl
llvm-svn: 326995
2018-03-08 10:53:34 +00:00
Paul Robinson a06f8dcca6 Recommit "[DWARFv5] Dump an MD5 checksum in the line-table header."
Adds missing support for DW_FORM_data16.

Update of r320852/r320886, fixing the unittest again, this time use a
raw char string for the test data.

Differential Revision: https://reviews.llvm.org/D41090

llvm-svn: 321011
2017-12-18 19:08:35 +00:00
Paul Robinson 6d0484f2b6 Revert "Recommit "[DWARFv5] Dump an MD5 checksum in the line-table header.""
This reverts commit 0afef672f63f0e4e91938656bc73424a8c058bfc.
Still failing at runtime on bots.

llvm-svn: 320888
2017-12-15 23:21:52 +00:00