Commit Graph

271 Commits

Author SHA1 Message Date
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
Aleksandr Urakov c43e086c74 Revert "Revert "[PDB] Extend IPDBSession's interface to retrieve frame data""
This reverts commit 466ce67d6ec444962e5cc0136243c16a453190c0.

llvm-svn: 345010
2018-10-23 08:14:53 +00:00
Aleksandr Urakov 738df2de7f Revert "[PDB] Extend IPDBSession's interface to retrieve frame data"
This reverts commit b5c7e2f9a4dbb34e3667c4bb4972735eadd3247a.

llvm-svn: 344909
2018-10-22 15:30:48 +00:00
Aleksandr Urakov d4a82f6f74 [PDB] Extend IPDBSession's interface to retrieve frame data
Summary:
This patch just extends the `IPDBSession` interface to allow retrieving
of frame data through it, and adds an implementation over DIA. It is needed
for an implementation (for now with DIA) of the conversion from FPO programs
to DWARF expressions mentioned in D53086.

Reviewers: zturner, asmith, rnk

Reviewed By: asmith

Subscribers: mgorny, aprantl, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D53324

llvm-svn: 344886
2018-10-22 07:18:08 +00:00
Zachary Turner b7471814cf Fix function signature to actually be an override.
llvm-svn: 342496
2018-09-18 16:58:17 +00:00
Nico Weber 1739dbf6a6 Introduce explicit add_unittest_with_input_files target for tests that use llvm::getInputFileDirectory()
Using llvm::getInputFileDirectory() in unit tests is discouraged, so require an explicit opt-in.
This way, cmake also writes ~60 fewer unused files to disk.

Differential Revision: https://reviews.llvm.org/D52095

llvm-svn: 342248
2018-09-14 17:34:46 +00:00
Zachary Turner cae734588f [PDB] Change uint32_t to SymIndex wherever it makes sense.
Although it's just a typedef, it helps for readability.  NFC.

llvm-svn: 341863
2018-09-10 21:30:59 +00:00
Fangrui Song 95dd7a25ba Quick fix for -DBUILD_SHARED_LIBS=on build after rL341502
libLLVMTestingSupport.so references a symbol in utils/unittest/UnitTestMain/TestMain.cpp (a layering issue) and will cause a link error because of -Wl,-z,defs (cmake/modules/HandleLLVMOptions.cmake)

Waiting zturner for a better fix.

llvm-svn: 341580
2018-09-06 19:51:20 +00:00
Zachary Turner d62d052c70 Fix a warning.
llvm-svn: 341561
2018-09-06 16:34:56 +00:00
Zachary Turner 7999b4fa48 [PDB] Refactor the PDB symbol classes to fix a reuse bug.
The way DIA SDK works is that when you request a symbol, it
gets assigned an internal identifier that is unique for the
life of the session.  You can then use this identifier to
get back the same symbol, with all of the same internal state
that it had before, even if you "destroyed" the original
copy of the object you had.

This didn't work properly in our native implementation, and
if you destroyed an object for a particular symbol, then
requested the same symbol again, it would get assigned a new
ID and you'd get a fresh copy of the object.  In order to fix
this some refactoring had to happen to properly reuse cached
objects.  Some unittests are added to verify that symbol
reuse is taking place, making use of the new unittest input
feature.

llvm-svn: 341503
2018-09-05 23:30:38 +00:00
Reid Kleckner bd5d71229d [codeview] Use push_macro to avoid conflicts instead of a prefix
Summary:
This prefix was added in r333421, and it changed our dumper output to
say things like "CVRegEAX" instead of just "EAX". That's a functional
change that I'd rather avoid.

I tested GCC, Clang, and MSVC, and all of them support #pragma
push_macro. They don't issue warnings whem the macro is not defined
either.

I don't have a Mac so I can't test the real termios.h header, but I
looked at the termios.h sources online and looked for other conflicts.
I saw only the CR* macros, so those are the ones we work around.

Reviewers: zturner, JDevlieghere

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50851

llvm-svn: 339907
2018-08-16 17:34:31 +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 7f33094486 [DebugInfo/DWARF] [2/4] Type units no longer in a std::deque. NFC
This is patch 2 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 2 takes the existing std::deque<DWARFUnitSection> for type units
and makes it a simple DWARFUnitSection, simplifying the handling of
type units and making it more consistent with compile units.

Differential Revision: https://reviews.llvm.org/D49742

llvm-svn: 338629
2018-08-01 20:46:46 +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
Alexandre Ganea ee8a720051 [CodeView] Minimal support for S_UNAMESPACE records
Differential Revision: https://reviews.llvm.org/D50007

llvm-svn: 338417
2018-07-31 19:15:50 +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 fac87b3dd7 dwarfgen: Don't create an AsmPrinter with an invalid ObjFile lowering
The AsmPrinter created in the tests contained an uninitialized
TargetLoweringObjectFile. Things mostly worked regardless, because we
used a separate instance of that class to specify sections to emit.

This rearanges the object construction order so that we can avoid
creating two lowering objects. Instead, we properly initialize the
object in the AsmPrinter, and have the DWARF generator store a pointer
to it.

llvm-svn: 338026
2018-07-26 13:16:06 +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
Zachary Turner ee8010abe3 Move some code from PDBFileBuilder to MSFBuilder.
The code to emit the pieces of the MSF file were actually in
PDBFileBuilder.  Move this to MSFBuilder so that we can
theoretically emit an MSF without having a PDB file.

llvm-svn: 335789
2018-06-27 21:18:15 +00:00
Jonas Devlieghere 43dce3edbe [CodeView] Add prefix to CodeView registers.
Adds CVReg to CodeView register names to prevent a duplicate symbol with
CR3 defined in termios.h, as suggested by Zachary on the mailing list.

http://lists.llvm.org/pipermail/llvm-dev/2018-May/123372.html

Differential revision: https://reviews.llvm.org/D47478

rdar://39863705

llvm-svn: 333421
2018-05-29 14:35:34 +00:00
James Henderson 004b729ed1 [DWARF] Refactor callback usage for .debug_line error handling
Change the "recoverable" error callback to take an Error instaed of a
string.

Reviewed by: JDevlieghere

Differential Revision: https://reviews.llvm.org/D46831

llvm-svn: 332845
2018-05-21 15:30:54 +00:00
Peter Collingbourne f7b81db715 MC: Change the streamer ctors to take an object writer instead of a stream. NFCI.
The idea is that a client that wants split dwarf would create a
specific kind of object writer that creates two files, and use it to
create the streamer.

Part of PR37466.

Differential Revision: https://reviews.llvm.org/D47050

llvm-svn: 332749
2018-05-18 18:26:45 +00:00
Nico Weber 9668e45b61 Inline a few CMake variables into their only uses.
No behavior change. Makes unittests CMakeLists.txt files more self-consistent.

llvm-svn: 332280
2018-05-14 19:23:31 +00:00
Simon Pilgrim affbc99bea Fix Wdocumentation warnings. NFCI.
llvm-svn: 332239
2018-05-14 12:22:30 +00:00
James Henderson 198a87c8f3 [DWARF] Remove unused member and fix(?) the unit-tests on big endian hosts
I can't verified the fix on a big endian host, so I'm not 100% certain it
will work.

llvm-svn: 331986
2018-05-10 14:36:24 +00:00
Roman Lebedev 85343925d7 [DWARF] DwarfGenerator.h LineTable: explicitly mark DG as unused
Just want to unbreak the build.

llvm-svn: 331984
2018-05-10 14:16:45 +00:00
Roman Lebedev e1b0e29e1e [DWARF] dwarfgen::LineTable::writeData(): pacify -Wcovered-switch-default
llvm-svn: 331983
2018-05-10 14:16:41 +00:00
Roman Lebedev a68aee07d5 [DWARF] DWARFDebugLineTest: fix a few more signed/unsigned mismatch warnings
llvm-svn: 331982
2018-05-10 14:16:37 +00:00
James Henderson 11a9de74c9 Fix signed/unsigned comparison warning and print format
The print format was causing at least 2 unit-test failures from r331971.

The signed/unsigned comparison warnings only appeared to affect two lines but
it was unclear whether it might just pop up on other lines, so I have been
explicit in all the literals in the tests.

There were other bot unit-test failures that I am still investigating.

llvm-svn: 331978
2018-05-10 12:15:43 +00:00
James Henderson a3acf99e59 [DWARF] Rework debug line parsing to use llvm::Error and callbacks
Reviewed by: dblaikie, JDevlieghere, espindola

Differential Revision: https://reviews.llvm.org/D44560

Summary:
The .debug_line parser previously reported errors by printing to stderr and
return false. This is not particularly helpful for clients of the library code,
as it prevents them from handling the errors in a manner based on the calling
context. This change switches to using llvm::Error and callbacks to indicate
what problems were detected during parsing, and has updated clients to handle
the errors in a location-specific manner. In general, this means that they
continue to do the same thing to external users. Below, I have outlined what
the known behaviour changes are, relating to this change.

There are two levels of "errors" in the new error mechanism, to broadly
distinguish between different fail states of the parser, since not every
failure will prevent parsing of the unit, or of subsequent unit. Malformed
table errors that prevent reading the remainder of the table (reported by
returning them) and other minor issues representing problems with parsing that
do not prevent attempting to continue reading the table (reported by calling a
specified callback funciton). The only example of this currently is when the
last sequence of a unit is unterminated. However, I think it would be good to
change the handling of unrecognised opcodes to report as minor issues as well,
rather than just printing to the stream if --verbose is used (this would be a
subsequent change however).

I have substantially extended the DwarfGenerator to be able to handle
custom-crafted .debug_line sections, allowing for comprehensive unit-testing
of the parser code. For now, I am just adding unit tests to cover the basic
error reporting, and positive cases, and do not currently intend to test every
part of the parser, although the framework should be sufficient to do so at a
later point.

Known behaviour changes:
  - The dump function in DWARFContext now does not attempt to read subsequent
  tables when searching for a specific offset, if the unit length field of a
  table before the specified offset is a reserved value.
  - getOrParseLineTable now returns a useful Error if an invalid offset is
  encountered, rather than simply a nullptr.
  - The parse functions no longer use `WithColor::warning` directly to report
  errors, allowing LLD to call its own warning function.
  - The existing parse error messages have been updated to not specifically
  include "warning" in their message, allowing consumers to determine what
  severity the problem is.
  - If the line table version field appears to have a value less than 2, an
  informative error is returned, instead of just false.
  - If the line table unit length field uses a reserved value, an informative
  error is returned, instead of just false.
  - Dumping of .debug_line.dwo sections is now implemented the same as regular
  .debug_line sections.
  - Verbose dumping of .debug_line[.dwo] sections now prints the prologue, if
  there is a prologue error, just like non-verbose dumping.

As a helper for the generator code, I have re-added emitInt64 to the
AsmPrinter code. This previously existed, but was removed way back in r100296,
presumably because it was dead at the time.

This change also requires a change to LLD, which will be committed separately.

llvm-svn: 331971
2018-05-10 10:51:33 +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
Nico Weber 432a38838d IWYU for llvm-config.h in llvm, additions.
See r331124 for how I made a list of files missing the include.
I then ran this Python script:

    for f in open('filelist.txt'):
        f = f.strip()
        fl = open(f).readlines()

        found = False
        for i in xrange(len(fl)):
            p = '#include "llvm/'
            if not fl[i].startswith(p):
                continue
            if fl[i][len(p):] > 'Config':
                fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
                found = True
                break
        if not found:
            print 'not found', f
        else:
            open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184
2018-04-30 14:59:11 +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
David Blaikie 4333f9700d Rename *CommandFlags.def to *CommandFlags.inc
These aren't the .def style files used in LLVM that require a macro
defined before their inclusion - they're just basic non-modular includes
to stamp out command line flag variables.

llvm-svn: 329840
2018-04-11 18:49:37 +00:00
Aaron Smith 860f0a5dd8 [DebugInfoPDB] Add missing test for findSymbolByRVA and findSymbolByAddr
llvm-svn: 329733
2018-04-10 18:12:49 +00:00
Alexandre Ganea 08df84e4f0 [DebugInfo][COFF] Fix reading variable-length encoded records
While reading Codeview records which contain variable-length encoded integers,
such as LF_BCLASS, LF_ENUMERATE, LF_MEMBER, LF_VBCLASS or LF_IVBCLASS,
the record's size would be improperly calculated in cases where the value was
indeed of a variable length (>= LF_NUMERIC). This caused a bad alignement on
the next record, which would/might crash later on.

Differential Revision: https://reviews.llvm.org/D45104

llvm-svn: 329659
2018-04-10 01:58:45 +00:00
Alexandre Ganea 3241cec577 Fix line endings (CR/LF -> LF) introduced by rL329613
reviewer: zturner
llvm-svn: 329646
2018-04-10 00:09:15 +00:00
Alexandre Ganea d9e96741c4 [Debuginfo][COFF] Minimal serialization support for precompiled types records
This change adds support for the LF_PRECOMP and LF_ENDPRECOMP records required
to read/write Microsoft precompiled types .objs.
See https://en.wikipedia.org/wiki/Precompiled_header#Microsoft_Visual_C_and_C++

This also adds handling for the .debug$P section, which is actually a .debug$T
section in disguise, found only in precompiled .objs.

Differential Revision: https://reviews.llvm.org/D45283

llvm-svn: 329613
2018-04-09 20:17:56 +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
Zachary Turner 3203e27473 [MSF] Default to FPM2, and always mark FPM pages allocated.
There are two FPMs in an MSF file, the idea being that for
incremental updates you can write to the alternate one and then
atomically swap them on commit.  LLVM defaulted to using FPM1
on the first commit, but this differs from Microsoft's behavior
which is to default to using FPM2 on the first commit.  To
eliminate some byte-level file differences, this patch changes
LLVM's default to also be FPM2.

Additionally, LLVM was trying to be "smart" about marking FPM
pages allocated.  In addition to marking every page belonging
to the alternate FPM as unallocated, LLVM also marked pages at
the end of the main FPM which were not needed as unallocated.

In order to match the behavior of Microsoft-generated PDBs, we
now always mark every FPM block as allocated, regardless of
whether it is in the main FPM or the alt FPM, and regardless of
whether or not it describes blocks which are actually in the file.

This has the side benefit of simplifying our code.

llvm-svn: 328812
2018-03-29 18:34:15 +00:00
Aaron Smith ed81a9db29 [DebugInfoPDB] Add DIA implementation of findLineNumbersByRVA
This method is used to find line numbers for PDBSymbolData
that have an invalid virtual address.

llvm-svn: 328586
2018-03-26 22:13:22 +00:00
Aaron Smith 53708a5e9e [DebugInfoPDB] Add DIA implementation of addressForVA and addressForRVA
These are used in finding line numbers for PDBSymbolData

llvm-svn: 328585
2018-03-26 22:10:02 +00:00
Aaron Smith 523de05a1f [DIA] Add IPDBSectionContrib interfaces and DIA implementation
To resolve symbol context at a particular address, we need to
determine the compiland for the address. We are able to determine
the parent compiland of PDBSymbolFunc, PDBSymbolTypeUDT,
PDBSymbolTypeEnum symbols indirectly through line information. 
However no such information is availabile for PDBSymbolData, 
i.e. variables.

The Section Contribution table from PDBs has information about
each compiland's contribution to sections by address. For example,
a piece of a contribution looks like,

  VA         RelativeVA  Sect No.  Offset    Length    Compiland
  14000087B0 000087B0    0001      000077B0  000000BB  exe_main.obj

So given an address, it's possible to determine its compiland with
this information.

llvm-svn: 328178
2018-03-22 04:08:15 +00:00
Zachary Turner eb62999455 [PDB] Don't ignore bucket 0 when writing the PDB string table.
The hash table is a list of buckets, and the *value* stored in
the bucket cannot be 0 since that is reserved.  However, the code
here was incorrectly skipping over the 0'th bucket entirely.
The 0'th bucket is perfectly fine, just none of these buckets
can contain the value 0.

As a result, whenever there was a string where hash(S) % Size
was equal to 0, we would write the value in the next bucket
instead.  We never caught this in our tests due to *another*
bug, which is that we would iterate the entire list of buckets
looking for the value, only using the hash value as a starting
point.  However, the real algorithm stops when it finds 0 in
a bucket since it takes that to mean "the item is not in the
hash table".

The unit test is updated to carefully construct a set of hash
values that will cause one item to hash to 0 mod bucket count,
and the reader is also updated to return an error indicating that
the item is not found when it encounters a 0 bucket.

llvm-svn: 328162
2018-03-21 22:23:59 +00:00
Pavel Labath 3461b1e097 HashTableTest: squelch some "comparison of integers of different signs" warnings
llvm-svn: 327701
2018-03-16 10:30:26 +00:00