766 Commits

Author SHA1 Message Date
Adrian Prantl
dce4a9aa59 Look for external types in all clang modules imported by the current symbol file.
This fixes a bug in -gmodules DWARF handling when debugging without a .dSYM bundle
that was particularly noticable when debugging LLVM itself.

Debugging without clang modules and DWO handling should be unaffected by this patch.

<rdar://problem/32436209>

llvm-svn: 321802
2018-01-04 16:42:05 +00:00
Aaron Smith
5a81bb73ad Remove duplicate declaration from D41550; NFC
llvm-svn: 321514
2017-12-28 07:48:10 +00:00
Aaron Smith
364cbfe964 Update failing PDB unit tests that are searching for symbols by regex
Summary: D41086 fixed an exception in FindTypes()/FindTypesByRegex() and caused two lldb unit test to fail. This change updates the unit tests to pass again.

Reviewers: zturner, lldb-commits, labath, clayborg, asmith

Reviewed By: asmith

Differential Revision: https://reviews.llvm.org/D41550

llvm-svn: 321511
2017-12-28 06:29:59 +00:00
Aaron Smith
86e9434db9 [lldb] Stop searching for a symbol in a pdb by regex
Summary:
It was possible when searching for a symbol by regex in a pdb that an invalid regex would cause an exception on Windows. This updates the code to avoid throwing an exception.

When fixing the exception it was decided there is no reason to search for a symbol in a pdb by regex. To support this, SymbolFilePDB::FindTypes() now only searches for types by name and no longer calls FindTypesByRegEx().

Reviewers: zturner, lldb-commits

Reviewed By: zturner

Subscribers: clayborg

Differential Revision: https://reviews.llvm.org/D41086

llvm-svn: 321344
2017-12-22 05:26:50 +00:00
Aaron Smith
1f8552abf3 Enable more abilities in SymbolFilePDB
Summary:
1) Finding symbols through --symfile
2) More abilities: Functions, Blocks, GlobalVariables, LocalVariables, VariableTypes

Reviewers: zturner, lldb-commits

Reviewed By: zturner

Subscribers: clayborg

Differential Revision: https://reviews.llvm.org/D41092

llvm-svn: 321327
2017-12-22 00:04:36 +00:00
Adrian Prantl
559d2c98a8 Bring clang options in error messages up to date.
llvm-svn: 321322
2017-12-21 23:04:51 +00:00
Pavel Labath
f1208e7aef ObjectFile: remove ReadSectionData/MemoryMapSectionData mutual recursion
Summary:
These two functions were calling each other, while handling different
branches of the if(IsInMemory()). This had a reason at some point in the
past, but right now it's just confusing.

I resolve this by removing the MemoryMapSectionData function and
inlining the !IsInMemory branch into ReadSectionData. There isn't
anything mmap-related in this function anyway, as the decision whether
to mmap is handled at a higher level.

This is a preparatory step to make ObjectFileELF be able to decompress
compressed sections (I want to make sure that all calls reading section
data are routed through a single piece of code).

Reviewers: clayborg

Subscribers: emaste, JDevlieghere, lldb-commits

Differential Revision: https://reviews.llvm.org/D41169

llvm-svn: 320705
2017-12-14 14:56:45 +00:00
Jan Kratochvil
4f39b294aa Prevent vain lldb::user_id_t 0xffffffff lookups
I have found LLDB commonly looks up lldb::user_id_t 0xffffffff failing to find
its DIE. One would rather expect LLDB_INVALID_UID == 0xffffffffffffffff in such
case.

DWARFASTParserClang.cpp:495
492             type_sp.reset(
493                 new Type(die.GetID(), dwarf, type_name_const_str, byte_size, NULL,
494                          DIERef(encoding_uid).GetUID(dwarf), encoding_data_type,
495                          &decl, clang_type, resolve_state));
encoding_uid = (DWARFFormValue) {m_cu = 0x0, m_form = 0, m_value = {value = {uval = 0, sval = 0, cstr = 0x0}, data = 0x0}}
-> DIERef::DIERef(const DWARFFormValue &form_value = {m_cu = 0x0, m_form = 0, m_value = {value = {uval = 0, sval = 0, cstr = 0x0}, data = 0x0}})
-> (DIERef) {cu_offset = 0xffffffff, die_offset = 0xffffffff}
-> lldb::user_id_t DIERef::GetUID(SymbolFileDWARF *dwarf = 0x61d00000b480) const
-> Type::Type(lldb::user_id_t encoding_uid = 0xffffffff)
But 0xffffffff !=
#define LLDB_INVALID_UID UINT64_MAX

Differential revision: https://reviews.llvm.org/D37492

llvm-svn: 319580
2017-12-01 20:14:09 +00:00
Jim Ingham
4e29eed498 ClangASTContext::ParseClassTemplateDecl doesn't always succeed.
When it does, it returns a NULL ClassTemplateDecl.  Don't use 
it if it is NULL...

<rdar://problem/35672107>

llvm-svn: 319516
2017-12-01 03:41:30 +00:00
Jan Kratochvil
bc3205e7bf refactor: Simplify loop with DWARFCompileUnit::Extract
Forgotten small simplification in D40212.

Differential revision: https://reviews.llvm.org/D40635

llvm-svn: 319402
2017-11-30 05:49:02 +00:00
Jan Kratochvil
ca9c2b290c refactor: Unify+simplify DWARFCompileUnit ctor+Clear() into in-class initializers + Extract()
It has no functionality effect.

I was concerned about the worse performance of DWARFDebugInfo::Parse this way
of allocating+destroying a CU for each iteration but I see it is now used only
by DWARFDebugInfo::Dump so that is no longer a problem.

Differential revision: https://reviews.llvm.org/D40212

llvm-svn: 319359
2017-11-29 21:13:11 +00:00
Jan Kratochvil
639e799c98 Due to changes for DWZ I would need to update those such as renaming it to
SetFileOffset.

Differential revision: https://reviews.llvm.org/D40458

llvm-svn: 318981
2017-11-25 17:16:56 +00:00
Jan Kratochvil
0f45abdef7 Remove 2 unused methods DWARFDebugInfo::Find and their FindCallbackString
Differential revision: https://reviews.llvm.org/D40216

llvm-svn: 318631
2017-11-19 19:04:24 +00:00
Jan Kratochvil
d7ff94f035 Add comments to DWARFCompileUnit length fields/methods
Differential revision: https://reviews.llvm.org/D40211

llvm-svn: 318626
2017-11-19 14:35:07 +00:00
Alexander Shaposhnikov
f413c7852e [lldb] Ensure that dwo/dwp are not double-indexed
DWO/DWP should not be indexed directly.
Instead, the corresponding base file should be used.
This diff adds an assert to DWARFCompileUnit::Index
and adjusts the methods 
SymbolFileDWARF::FindCompleteObjCDefinitionTypeForDIE,
SymbolFileDWARF::GetObjCMethodDIEOffsets accordingly.

Differential revision: https://reviews.llvm.org/D39825

llvm-svn: 318554
2017-11-17 20:50:54 +00:00
Pavel Labath
5f19b90783 Move ArchSpec to the Utility module
The rationale here is that ArchSpec is used throughout the codebase,
including in places which should not depend on the rest of the code in
the Core module.

This commit touches many files, but most of it is just renaming of
 #include lines. In a couple of cases, I removed the #include ArchSpec
line altogether, as the file was not using it. In one or two places,
this necessitated adding other #includes like lldb-private-defines.h.

llvm-svn: 318048
2017-11-13 16:16:33 +00:00
Alexander Shaposhnikov
7fd4a2c477 [lldb] Remove unused method declaration
FindCompleteObjCDefinitionType is not used anywhere and there is no implementation of it, only a declaration.

Test plan: make check-lldb

Differential revision: https://reviews.llvm.org/D39884

llvm-svn: 317919
2017-11-10 19:40:53 +00:00
Tamas Berghammer
5976583a30 Support scoped enums in the DWARF AST parser
Subscribers: JDevlieghere

Differential Revision: https://reviews.llvm.org/D39545

llvm-svn: 317563
2017-11-07 10:39:22 +00:00
Alexander Shaposhnikov
64b4bcfa05 [lldb] Enable using out-of-tree dwps
Previously LLDB required the DWP file 
to be located next to the executable file.
This diff uses the helper function 
Symbols::LocateExecutableSymbolFile to search for 
DWP files in the standard locations for debug symbols.

Test plan:

Build a toy test example:
main.cpp
clang -gsplit-dwarf -g -O0 main.cpp -o main.exe
llvm-dwp -e main.exe -o main.exe.dwp
mkdir -p debug_symbols
mv main.exe.dwp debug_symbols/main.exe.dwp

Run lldb:
lldb
settings set target.debug-file-search-paths ./debug_symbols
file ./main.exe
br set --name f
run

Check that debugging works:
setting breakpoints, printing local variables.

Differential revision: https://reviews.llvm.org/D38568

llvm-svn: 315387
2017-10-10 23:28:34 +00:00
Davide Italiano
b06e8fa223 [DWARFDIE] Rewrite operator != using operator ==. NFCI.
llvm-svn: 315200
2017-10-09 00:18:45 +00:00
Davide Italiano
54bb5ea21a [SymbolFile/DWARF] Simplify two functions. NFCI.
llvm-svn: 315199
2017-10-09 00:11:49 +00:00
Alexander Shaposhnikov
56138de385 [lldb] Fix initialization of m_debug_cu_index_map
SymbolFileDWARFDwp contains m_debug_cu_index_map which was previously 
initialized incorrectly: before m_debug_cu_index.parse 
is called m_debug_cu_index is empty, thus 
the map was not actually getting populated properly. 
This diff moves this step into a private helper method
and calls it after m_debug_cu_index.parse inside SymbolFileDWARFDwp::Create.

Test plan:

Build a toy test example 
main.cpp
clang -gsplit-dwarf -g -O0 main.cpp -o main.exe
llvm-dwp -e main.exe -o main.exe.dwp
Build LLDB with ENABLE_DEBUG_PRINTF set.
Run: lldb -- ./main.exe
Check that the indexes are now correct 
(before this change they were empty)
Check that debugging works 
(setting breakpoints, printing local variables (this was not working before))

Differential revision: http://reviews.llvm.org/D38492

llvm-svn: 314832
2017-10-03 19:56:21 +00:00
Ed Maste
d13f691f41 Improve FreeBSD kernel debugging
FreeBSD kernel modules are actually relocatable (.o) ELF files and this
previously caused some issues for LLDB. This change addresses these when
using lldb to symbolicate FreeBSD kernel backtraces. 

The major problems:

- Relocations were not being applied to the DWARF debug info despite
  there being code to do this. Several issues prevented it from working:

  - Relocations are computed at the same time as the symbol table, but
    in the case of split debug files, symbol table parsing always
    redirects to the primary object file, meaning that relocations would
    never be applied in the debug file.

  - There's actually no guarantee that the symbol table has been parsed
    yet when trying to parse debug information.

  - When actually applying relocations, it will segfault because the
    object files are not mapped with MAP_PRIVATE and PROT_WRITE.

- LLDB returned invalid results when performing ordinary address-to-
  symbol resolution. It turned out that the addresses specified in the
  section headers were all 0, so LLDB believed all the sections had
  overlapping "file addresses" and would sometimes return a symbol from
  the wrong section.

Patch by Brian Koropoff

Differential Revision:	https://reviews.llvm.org/D38142

llvm-svn: 314672
2017-10-02 14:35:07 +00:00
Francis Ricci
7ddfe8ef75 Use ThreadLauncher to launch TaskPool threads
Summary:
This allows for the stack size to be configured, which isn't
possible with std::thread. Prevents overflowing the stack when
performing complex operations in the task pool on darwin,
where the default pthread stack size is only 512kb.

This also moves TaskPool from Utility to Host.

Reviewers: labath, tberghammer, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D37930

llvm-svn: 313637
2017-09-19 15:38:30 +00:00
Alexander Shaposhnikov
ff7b03fc85 [lldb] Adjust UpdateExternalModuleListIfNeeded method for the case of *.dwo
When LLDB loads "external" modules it looks at the
presence of DW_AT_GNU_dwo_name.
However, when the already created module
(corresponding to .dwo itself) is being processed,
it will see the presence of DW_AT_GNU_dwo_name
(which contains the name of dwo file) and
will try to call ModuleList::GetSharedModule again.
In some cases (i.e. for empty files) Clang 4.0
generates a *.dwo file which has DW_AT_GNU_dwo_name,
but no DW_AT_comp_dir. In this case the method
ModuleList::GetSharedModule will fail and
the warning will be printed. To workaround this issue, 
one can notice that in this case we don't actually need 
to try to load the already loaded module (corresponding to .dwo).

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D37295

llvm-svn: 313083
2017-09-12 22:14:36 +00:00
Saleem Abdulrasool
6c13510c10 Plugins: fix resolution ambiguity in PDB plugin
A clang change caused the inclusion of `llvm::Type` and
`lldb_private::Type` to be pulled into the global namespace due to the
`using namespace llvm;` and `using namespace lldb_private;`.  Explicitly
qualify the `Type` to resolve the ambiguity.  NFC

llvm-svn: 312841
2017-09-09 00:13:49 +00:00
Jan Kratochvil
75a79e72ae Fix DW_FORM_strp parsing
Differential revision: https://reviews.llvm.org/D37441

llvm-svn: 312562
2017-09-05 19:01:01 +00:00
Tamas Berghammer
963ce483b8 Add support for the DWP debug info format
Summary:
The DWP (DWARF package) format is used to pack multiple dwo files
generated by split-dwarf into a single ELF file to make distributing
them easier. It is part of the DWARFv5 spec and can be generated by
dwp or llvm-dwp from a set of dwo files.

Caviats:
* Only the new version of the dwp format is supported (v2 in GNU
  numbering schema and v5 in the DWARF spec). The old version (v1) is
  already deprecated but binutils 2.24 still generates that one.
* Combining DWP files with module debugging is not yet supported.

Subscribers: emaste, mgorny, aprantl

Differential Revision: https://reviews.llvm.org/D36062

llvm-svn: 311775
2017-08-25 13:56:14 +00:00
Tamas Berghammer
bba2c83493 Remove the DWARFExpression -> Clang ExpressionParser dependency
It was completly unused and broke the part of the encapsulation that
common code shouldn't depend on specific plugins or language specific
features.

llvm-svn: 311000
2017-08-16 11:45:10 +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
Tamas Berghammer
15cf379519 Add support for base address entries in the .debug_ranges section
Summary:
Clang recently started to emit base address entries into the
.debug_ranges section to reduce the number of relocations needed. Lets
make sure LLDB can read them.

llvm-svn: 309554
2017-07-31 10:26:19 +00:00
Adrian Prantl
4b2113036d Improve the fix for PR33875 by not hardcoding the section name.
This is a follow-up to r308905.

llvm-svn: 309019
2017-07-25 20:12:25 +00:00
Greg Clayton
ea5df1049b Don't allow .debug_types to be parsed as LLDB can crash when enums are not able to be found.
Differential Revision: https://reviews.llvm.org/D35734

llvm-svn: 308911
2017-07-24 18:40:33 +00:00
Adrian Prantl
8bbb130793 RFix PR33875 by distinguishing between DWO and clang modules.
This reapplies https://reviews.llvm.org/D35740 with a tweak to find
the section by name rather than type. Section types don't distinguish
between regular sections and their DWO counterparts.

llvm-svn: 308905
2017-07-24 18:06:39 +00:00
Adrian Prantl
ed6f69c111 Revert "Fix PR33875 by distinguishing between DWO and clang modules"
This reverts commit r308850.

llvm-svn: 308851
2017-07-23 20:24:41 +00:00
Adrian Prantl
651166c2d2 Fix PR33875 by distinguishing between DWO and clang modules
The DWO handling code can get confused by clang modules which also use
skeleton CUs to point to the object file with the full debug
info. This patch detects whether an object is a "real" DWO or a clang
module and prevents LLDB from interpreting clang modules as DWO. This
fixes the regression in TestWithModuleDebugging.

http://llvm.org/bugs/show_bug.cgi?id=33875

Differential Revision: https://reviews.llvm.org/D35740

llvm-svn: 308850
2017-07-23 17:59:07 +00:00
Pavel Labath
38d0632e6a Move Timer and TraceOptions from Core to Utility
Summary:
The classes have no dependencies, and they are used both by lldb and
lldb-server, so it makes sense for them to live in the lowest layers.

Reviewers: zturner, jingham

Subscribers: emaste, mgorny, lldb-commits

Differential Revision: https://reviews.llvm.org/D34746

llvm-svn: 306682
2017-06-29 14:32:17 +00:00
Pavel Labath
92f6677159 Switch TaskMapOverInt to llvm::function_ref
The function does not persist the callback, so using a lighter-weight
asbtraction seems appropriate.

Also tweak the signatures of the lambdas to match what the TaskMap
interface expects.

llvm-svn: 304924
2017-06-07 16:28:08 +00:00
Pavel Labath
32f29fac41 Fix assorted compiler warnings. NFC
llvm-svn: 304796
2017-06-06 14:06:22 +00:00
Pavel Labath
f9d1647657 Remove an expensive lock from Timer
The Timer destructor would grab a global mutex in order to update
execution time. Add a class to define a category once, statically; the
class adds itself to an atomic singly linked list, and thus subsequent
updates only need to use an atomic rather than grab a lock and perform a
hashtable lookup.

Differential Revision: https://reviews.llvm.org/D32823
Patch by Scott Smith <scott.smith@purestorage.com>.

llvm-svn: 303058
2017-05-15 13:02:37 +00:00
Zachary Turner
97206d5727 Rename Error -> Status.
This renames the LLDB error class to Status, as discussed
on the lldb-dev mailing list.

A change of this magnitude cannot easily be done without
find and replace, but that has potential to catch unwanted
occurrences of common strings such as "Error".  Every effort
was made to find all the obvious things such as the word "Error"
appearing in a string, etc, but it's possible there are still
some lingering occurences left around.  Hopefully nothing too
serious.

llvm-svn: 302872
2017-05-12 04:51:55 +00:00
Sean Callanan
09e91ac6ab [DWARF parser] Produce correct template parameter packs
Templates can end in parameter packs, like this

template <class T...> struct MyStruct 
  { /*...*/ };

LLDB does not currently support these parameter packs; 
it does not emit them into the template argument list
at all. This causes problems when you specialize, e.g.:

template <> struct MyStruct<int> 
  { /*...*/ };
template <> struct MyStruct<int, int> : MyStruct<int> 
  { /*...*/ };

LLDB generates two template specializations, each with 
no template arguments, and then when they are imported 
by the ASTImporter into a parser's AST context we get a 
single specialization that inherits from itself, 
causing Clang's record layout mechanism to smash its
stack.

This patch fixes the problem for classes and adds
tests. The tests for functions fail because Clang's
ASTImporter can't import them at the moment, so I've
xfailed that test.

Differential Revision: https://reviews.llvm.org/D33025

llvm-svn: 302833
2017-05-11 22:08:05 +00:00
Pavel Labath
5c913e9973 Add TaskMap for iterating a function over a set of integers
Summary:
Many parallel tasks just want to iterate over all the possible numbers from 0 to N-1.  Rather than enqueue N work items, instead just "map" the function across the requested integer space.

Reviewers: clayborg, labath, tberghammer, zturner

Reviewed By: clayborg, zturner

Subscribers: zturner, lldb-commits

Differential Revision: https://reviews.llvm.org/D32757
Patch by Scott Smith <scott.smith@purestorage.com>.

llvm-svn: 302223
2017-05-05 11:16:59 +00:00
Pavel Labath
4d35d6b3b3 Change UniqueCStringMap to use ConstString as the key
Summary:
UniqueCStringMap "sorts" the entries for fast lookup, but really it only cares about uniqueness.  ConstString can be compared by pointer alone, rather than with strcmp, resulting in much faster comparisons.  Change the interface to take ConstString instead, and propagate use of the type to the callers where appropriate.

Reviewers: #lldb, clayborg

Reviewed By: clayborg

Subscribers: labath, jasonmolenda, lldb-commits

Differential Revision: https://reviews.llvm.org/D32316
Patch by Scott Smith <scott.smith@purestorage.com>.

llvm-svn: 301908
2017-05-02 10:17:30 +00:00
Jim Ingham
7fca8c0757 Provide a mechanism to do some pre-loading of symbols up front.
Loading a shared library can require a large amount of work; rather than do that serially for each library,
this patch will allow parallelization of the symbols and debug info name indexes.

From scott.smith@purestorage.com

https://reviews.llvm.org/D32598

llvm-svn: 301609
2017-04-28 00:51:06 +00:00
Sean Callanan
b494578afb [DWARF] Fix lookup in the abstract origins of inlined blocks/functions
LLDB uses clang::DeclContexts for lookups, and variables get put into
the DeclContext for their abstract origin. (The abstract origin is a 
DWARF pointer that indicates the unique definition of inlined code.) 
When the expression parser is looking for variables, it locates the 
DeclContext for the current context. This needs to be done carefully, 
though, e.g.:

__attribute__ ((always_inline)) void f(int a) {
  {
    int b = a * 2;
  }
}

void g() {
  f(3);
}
Here, if we're stopped in the inlined copy of f, we have to find the 
DeclContext corresponding to the definition of f – its abstract 
origin. Clang doesn't allow multiple functions with the same name and 
arguments to exist. It also means that any variables we see must be 
placed in the appropriate DeclContext.

[Bug 1]: When stopped in an inline block, the function 
GetDeclContextDIEContainingDIE for that block doesn't properly
construct a DeclContext for the abstract origin for inlined
subroutines. That means we get duplicated function DeclContexts, but
function arguments only get put in the abstract origin's DeclContext, 
and as a result when we try to look for them in nested contexts they 
aren't found.

[Bug 2]: When stopped in an inline block, the DWARF (for space 
reasons) doesn't explicitly point to the abstract origin for that 
block. This means that the function GetClangDeclContextForDIE returns
a different DeclContext for each place the block is inlined. However, 
any variables defined in the block have abstract origins, so they 
will only get placed in the DeclContext for their abstract origin.

In this fix, I've introduced a test covering both of these issues,
and fixed them.

Bug 1 could be resolved simply by making sure we look up the abstract
origin for inlined functions when looking up their DeclContexts on 
behalf of nested blocks.

For Bug 2, I've implemented an algorithm that makes the DeclContext 
for a block be the containing DeclContext for the closest entity we
would find during lookup that has an abstract origin pointer. That
means that in the following situation:

{ // block 1
  int a;
  { // block 2
    int b;
  }
}
if we looked up the DeclContext for block 2, we'd find the block 
containing the abstract origin of b, and lookup would proceed 
correctly because we'd see b and a. However, in the situation

{ // block 1
  int a;
  { // block 2
  }
}
since there isn't anything to look up in block 2, we can't determine 
its abstract origin (and there is no such pointer in the DWARF for 
blocks). However, we can walk up the parent chain and find a, and its 
abstract origin lives in the abstract origin of block 1. So we simply 
say that the DeclContext for block 2 is the same as the DeclContext 
for block 1, which contains a. Lookups will return the same results.

Thanks to Jim Ingham for review and suggestions.

Differential revision: https://reviews.llvm.org/D32375

llvm-svn: 301263
2017-04-24 22:11:10 +00:00
Pavel Labath
775588c0c3 Remove lldb streams from the Log class completely
Summary:
previously we switched to llvm streams for log output, this completes
the switch for the error streams.

I also clean up the includes and remove the unused argument from
DisableAllLogChannels().

This required adding a bit of boiler plate to convert the output in the
command interpreter, but that should go away when we switch command
results to use llvm streams as well.

Reviewers: zturner, eugene

Subscribers: lldb-commits, emaste

Differential Revision: https://reviews.llvm.org/D30894

llvm-svn: 297812
2017-03-15 09:06:58 +00:00
Jason Molenda
19cf689a9e Simplify & correct the patch I wrote in r297441, after thinking
about this more I realized I could make the change isolated to
whether we decide an empty accelerator table is valid or not.
<rdar://problem/30867462>

llvm-svn: 297496
2017-03-10 19:31:54 +00:00
Jason Molenda
bc3a47f31d Add a distinction in an apple accelerator table between IsValid and
HasContent.  If we have a valid accelerator table which has no
content, we want to depend on that (empty) table as the authoritative
source instead of reading through all the debug info for lookups.
<rdar://problem/30867462> 

llvm-svn: 297441
2017-03-10 06:38:19 +00:00
Zachary Turner
7d86ee5ab0 Resubmit FileSystem changes.
This was originall reverted due to some test failures in
ModuleCache and TestCompDirSymlink.  These issues have all
been resolved and the code now passes all tests.

Differential Revision: https://reviews.llvm.org/D30698

llvm-svn: 297300
2017-03-08 17:56:08 +00:00