Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
This is a retry of the original patch https://reviews.llvm.org/D113965 which was reverted. There was a deadlock in the Manual DWARF indexing code during symbol preloading where the module was asked on the main thread to preload its symbols, and this would in turn cause the DWARF manual indexing to use a thread pool to index all of the compile units, and if there were relocations on the debug information sections, these threads could ask the ObjectFile to load section contents, which could cause a call to ObjectFileELF::RelocateSection() which would ask for the symbol table from the module and it would deadlock. We can't lock the module in ObjectFile::GetSymtab(), so the solution I am using is to use a llvm::once_flag to create the symbol table object once and then lock the Symtab object. Since all APIs on the symbol table use this lock, this will prevent anyone from using the symbol table before it is parsed and finalized and will avoid the deadlock I mentioned. ObjectFileELF::GetSymtab() was never locking the module lock before and would put off creating the symbol table until somewhere inside ObjectFileELF::GetSymtab(). Now we create it one time inside of the ObjectFile::GetSymtab() and immediately lock it which should be safe enough. This avoids the deadlocks and still provides safety.
Differential Revision: https://reviews.llvm.org/D114288
This reverts commit 951b107eed.
Buildbots were failing, there is a deadlock in /Users/gclayton/Documents/src/llvm/clean/llvm-project/lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s when ELF files try to relocate things.
Symbol table parsing has evolved over the years and many plug-ins contained duplicate code in the ObjectFile::GetSymtab() that used to be pure virtual. With this change, the "Symbtab *ObjectFile::GetSymtab()" is no longer virtual and will end up calling a new "void ObjectFile::ParseSymtab(Symtab &symtab)" pure virtual function to actually do the parsing. This helps centralize the code for parsing the symbol table and allows the ObjectFile base class to do all of the common work, like taking the necessary locks and creating the symbol table object itself. Plug-ins now just need to parse when they are asked to parse as the ParseSymtab function will only get called once.
Differential Revision: https://reviews.llvm.org/D113965
The new module stats adds the ability to measure the time it takes to parse and index the symbol tables for each module, and reports modules statistics in the output of "statistics dump" along with the path, UUID and triple of the module. The time it takes to parse and index the symbol tables are also aggregated into new top level key/value pairs at the target level.
Differential Revision: https://reviews.llvm.org/D112279
This patch deals with ObjectFile, ObjectContainer and OperatingSystem
plugins. I'll convert the other types in separate patches.
In order to enable piecemeal conversion, I am leaving some ConstStrings
in the lowest PluginManager layers. I'll convert those as the last step.
Differential Revision: https://reviews.llvm.org/D112061
There is no reason why this function should be returning a ConstString.
While modifying these files, I also fixed several instances where
GetPluginName and GetPluginNameStatic were returning different strings.
I am not changing the return type of GetPluginNameStatic in this patch, as that
would necessitate additional changes, and this patch is big enough as it is.
Differential Revision: https://reviews.llvm.org/D111877
.. and reduce the scope of others. They don't follow llvm coding
standards (which say they should be used only when the same effect
cannot be achieved with the static keyword), and they set a bad example.
In all these years, we haven't found a use for this function (it has
zero callers). Lets just remove the boilerplate.
Differential Revision: https://reviews.llvm.org/D109600
This is a resubmission of https://reviews.llvm.org/D105160 after fixing testing issues.
This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.
Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.
This patch fixes the issue by:
not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool
Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)
After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)
The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.
Differential Revision: https://reviews.llvm.org/D106837
This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.
Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.
This patch fixes the issue by:
- not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
- doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
- removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool
Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)
After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)
The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.
Differential Revision: https://reviews.llvm.org/D105160
Reverts commits:
"Fix failing tests after https://reviews.llvm.org/D104488."
"Fix buildbot failure after https://reviews.llvm.org/D104488."
"Create synthetic symbol names on demand to improve memory consumption and startup times."
This series of commits broke the windows lldb bot and then failed to fix all of the failing tests.
This fix was created after profiling the target creation of a large C/C++/ObjC application that contained almost 4,000,000 redacted symbol names. The symbol table parsing code was creating names for each of these synthetic symbols and adding them to the name indexes. The code was also adding the object file basename to the end of the symbol name which doesn't allow symbols from different shared libraries to share the names in the constant string pool.
Prior to this fix this was creating 180MB of "___lldb_unnamed_symbol" symbol names and was taking a long time to generate each name, add them to the string pool and then add each of these names to the name index.
This patch fixes the issue by:
- not adding a name to synthetic symbols at creation time, and allows name to be dynamically generated when accessed
- doesn't add synthetic symbol names to the name indexes, but catches this special case as name lookup time. Users won't typically set breakpoints or lookup these synthetic names, but support was added to do the lookup in case it does happen
- removes the object file baseanme from the generated names to allow the names to be shared in the constant string pool
Prior to this fix the startup times for a large application was:
12.5 seconds (cold file caches)
8.5 seconds (warm file caches)
After this fix:
9.7 seconds (cold file caches)
5.7 seconds (warm file caches)
The names of the symbols are auto generated by appending the symbol's UserID to the end of the "___lldb_unnamed_symbol" string and is only done when the name is requested from a synthetic symbol if it has no name.
Differential Revision: https://reviews.llvm.org/D104488
The code used the total number of symbols to create a symbol ID for the
synthetic symbols. This is not correct because the IDs of real symbols
can be higher than their total number, as we do not add all symbols (and
in particular, we never add symbol zero, which is not a real symbol).
This meant we could have symbols with duplicate IDs, which caused
problems if some relocations were referring to the duplicated IDs. This
was the cause of the failure of the test D97786.
This patch fixes the code to use the ID of the highest (last) symbol
instead.
Commiting this patch for Augusto Noronha who is getting set
up still.
This patch changes Target::ReadMemory so the default behavior
when a read is in a Section that is read-only is to fetch the
data from the local binary image, instead of reading it from
memory. Update all callers to use their old preferences
(the old prefer_file_cache bool) using the new API; we should
revisit these calls and see if they really intend to read
live memory, or if reading from a read-only Section would be
equivalent and important for performance-sensitive cases.
rdar://30634422
Differential revision: https://reviews.llvm.org/D100338
LLDB can often appear deadlocked to users that use IDEs when it is indexing DWARF, or parsing symbol tables. These long running operations can make a debug session appear to be doing nothing even though a lot of work is going on inside LLDB. This patch adds a public API to allow clients to listen to debugger events that report progress and will allow UI to create an activity window or display that can show users what is going on and keep them informed of expensive operations that are going on inside LLDB.
Differential Revision: https://reviews.llvm.org/D97739
It is possible for the GetSectionHeaderByIndex lookup to fail because
the previous FindSectionContainingFileAddress lookup found a segment
instead of a section. This is possible if the binary does not have
a PLT (which means that lld will in some circumstances set DT_JMPREL
to 0, which is typically an address that is part of the ELF headers
and not in a section) and may also be possible if the section headers
have been stripped. To handle this possibility, replace the assert
with an if.
Differential Revision: https://reviews.llvm.org/D93438
Adds the RISC-V ArchSpec bits contributed by @simoncook as part of D62732,
plus logic to distinguish between riscv32 and riscv64 based on ELF class.
The patch follows the implementation approach previously used for MIPS.
It defines RISC-V architecture subtypes and inspects the ELF header,
namely the ELF class, to detect the right subtype.
Differential Revision: https://reviews.llvm.org/D86292
This patch introduces a LLDB_SCOPED_TIMER macro to hide the needlessly
repetitive creation of scoped timers in LLDB. It's similar to the
LLDB_LOG(F) macro.
Differential revision: https://reviews.llvm.org/D93663
Summary:
This patch extends the ModuleSpec class to include a
DataBufferSP which contains the module data. If this
data is provided, LLDB won't try to hit the filesystem
to create the Module, but use only the data stored in
the ModuleSpec.
Reviewers: labath, espindola
Subscribers: emaste, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D83512
Leverage ARM ELF build attribute section to create ELF attribute section
for RISC-V. Extract the common part of parsing logic for this section
into ELFAttributeParser.[cpp|h] and ELFAttributes.[cpp|h].
Differential Revision: https://reviews.llvm.org/D74023
This is a step towards making the initialize and terminate calls be
generated by CMake, which in turn is towards making it possible to
disable plugins at configuration time.
Differential revision: https://reviews.llvm.org/D74245
Scale segment identifier up to user_id_t before negating it. This fixes
the identifers being wrongly e.g. 0x00000000fffffffe instead of
0xfffffffffffffffe. Fix suggested by Pavel Labath.
This fixes 5 tests failing on i386 (PR #44748):
lldb-shell :: ObjectFile/ELF/PT_LOAD-overlap-PT_INTERP.yaml
lldb-shell :: ObjectFile/ELF/PT_LOAD-overlap-PT_TLS.yaml
lldb-shell :: ObjectFile/ELF/PT_LOAD-overlap-section.yaml
lldb-shell :: ObjectFile/ELF/PT_LOAD.yaml
lldb-shell :: ObjectFile/ELF/PT_TLS-overlap-PT_LOAD.yaml
Differential Revision: https://reviews.llvm.org/D73914
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).
This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).
Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere
Reviewed By: JDevlieghere
Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73258
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.
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
Testing whether a name is mangled or not is extremely cheap and can be
done by looking at the first two characters. Mangled knows how to do
it. On the flip side, many call sites that currently pass in an
is_mangled determination do not know how to correctly do it (for
example, they leave out Swift mangling prefixes).
This patch removes this entry point and just forced Mangled to
determine the mangledness of a string itself.
Differential Revision: https://reviews.llvm.org/D68674
llvm-svn: 374180
David added the JamCRC implementation in r246590. More recently, Eugene
added a CRC-32 implementation in r357901, which falls back to zlib's
crc32 function if present.
These checksums are essentially the same, so having multiple
implementations seems unnecessary. This replaces the CRC-32
implementation with the simpler one from JamCRC, and implements the
JamCRC interface in terms of CRC-32 since this means it can use zlib's
implementation when available, saving a few bytes and potentially making
it faster.
JamCRC took an ArrayRef<char> argument, and CRC-32 took a StringRef.
This patch changes it to ArrayRef<uint8_t> which I think is the best
choice, and simplifies a few of the callers nicely.
Differential revision: https://reviews.llvm.org/D68570
llvm-svn: 374148
Summary:
This is a redo of D68069 because I reverted it due to some concerns that were now addressed along with the new comments that @labath added.
I found a case where the main android binary (app_process32) had thumb code at its entry point but no entry in the symbol table indicating this. This made lldb set a 4 byte breakpoint at that address (we default to arm code) instead of a 2 byte one (like we should for thumb).
The big deal with this is that the expression evaluator uses the entry point as a way to know when a JITed expression has finished executing by putting a breakpoint there. Because of this, evaluating expressions on certain android devices (Google Pixel something) made the process crash.
This was fixed by checking this specific situation when we parse the symbol table and add an artificial symbol for this 2 byte range and indicating that it's arm thumb.
I created 2 unit tests for this, one to check that now we know that the entry point is arm thumb, and the other to make sure we didn't change the behaviour for arm code.
I also run the following on the command line with the `app_process32` where I found the issue:
**Before:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32[0x1640]: .long 0xf0004668 ; unknown opcode
```
**After:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32`:
app_process32[0x1640] <+0>: mov r0, sp
app_process32[0x1642]: andeq r0, r0, r0
```
Reviewers: clayborg, labath, wallace, espindola
Reviewed By: labath
Subscribers: labath, lldb-commits, MaskRay, kristof.beyls, arichardson, emaste, srhines
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68533
llvm-svn: 374132
Summary:
If the .symtab section is stripped from the binary it might be that
there's a .gnu_debugdata section which contains a smaller .symtab in
order to provide enough information to create a backtrace with function
names or to set and hit a breakpoint on a function name.
This change looks for a .gnu_debugdata section in the ELF object file.
The .gnu_debugdata section contains a xz-compressed ELF file with a
.symtab section inside. Symbols from that compressed .symtab section
are merged with the main object file's .dynsym symbols (if any).
In addition we always load the .dynsym even if there's a .symtab
section.
For example, the Fedora and RHEL operating systems strip their binaries
but keep a .gnu_debugdata section. While gdb already can read this
section, LLDB until this patch couldn't. To test this patch on a
Fedora or RHEL operating system, try to set a breakpoint on the "help"
symbol in the "zip" binary. Before this patch, only GDB can set this
breakpoint; now LLDB also can do so without installing extra debug
symbols:
lldb /usr/bin/zip -b -o "b help" -o "r" -o "bt" -- -h
The above line runs LLDB in batch mode and on the "/usr/bin/zip -h"
target:
(lldb) target create "/usr/bin/zip"
Current executable set to '/usr/bin/zip' (x86_64).
(lldb) settings set -- target.run-args "-h"
Before the program starts, we set a breakpoint on the "help" symbol:
(lldb) b help
Breakpoint 1: where = zip`help, address = 0x00000000004093b0
Once the program is run and has hit the breakpoint we ask for a
backtrace:
(lldb) r
Process 10073 stopped
* thread #1, name = 'zip', stop reason = breakpoint 1.1
frame #0: 0x00000000004093b0 zip`help
zip`help:
-> 0x4093b0 <+0>: pushq %r12
0x4093b2 <+2>: movq 0x2af5f(%rip), %rsi ; + 4056
0x4093b9 <+9>: movl $0x1, %edi
0x4093be <+14>: xorl %eax, %eax
Process 10073 launched: '/usr/bin/zip' (x86_64)
(lldb) bt
* thread #1, name = 'zip', stop reason = breakpoint 1.1
* frame #0: 0x00000000004093b0 zip`help
frame #1: 0x0000000000403970 zip`main + 3248
frame #2: 0x00007ffff7d8bf33 libc.so.6`__libc_start_main + 243
frame #3: 0x0000000000408cee zip`_start + 46
In order to support the .gnu_debugdata section, one has to have LZMA
development headers installed. The CMake section, that controls this
part looks for the LZMA headers and enables .gnu_debugdata support by
default if they are found; otherwise or if explicitly requested, the
minidebuginfo support is disabled.
GDB supports the "mini debuginfo" section .gnu_debugdata since v7.6
(2013).
Reviewers: espindola, labath, jankratochvil, alexshap
Reviewed By: labath
Subscribers: rnkovacs, wuzish, shafik, emaste, mgorny, arichardson, hiraditya, MaskRay, lldb-commits
Tags: #lldb, #llvm
Differential Revision: https://reviews.llvm.org/D66791
llvm-svn: 373891
Backing out because SymbolFile/Breakpad/symtab.test is failing and it seems to be a legit issue. Will investigate.
This reverts commit 72153f95ee4c1b52d2f4f483f0ea4f650ec863be.
llvm-svn: 373687
Summary:
I found a case where the main android binary (app_process32) had thumb code at its entry point but no entry in the symbol table indicating this. This made lldb set a 4 byte breakpoint at that address (we default to arm code) instead of a 2 byte one (like we should for thumb).
The big deal with this is that the expression evaluator uses the entry point as a way to know when a JITed expression has finished executing by putting a breakpoint there. Because of this, evaluating expressions on certain android devices (Google Pixel something) made the process crash.
This was fixed by checking this specific situation when we parse the symbol table and add an artificial symbol for this 2 byte range and indicating that it's arm thumb.
I created 2 unit tests for this, one to check that now we know that the entry point is arm thumb, and the other to make sure we didn't change the behaviour for arm code.
I also run the following on the command line with the `app_process32` where I found the issue:
**Before:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32[0x1640]: .long 0xf0004668 ; unknown opcode
```
**After:**
```
(lldb) dis -s 0x1640 -e 0x1644
app_process32`:
app_process32[0x1640] <+0>: mov r0, sp
app_process32[0x1642]: andeq r0, r0, r0
```
Reviewers: clayborg, labath, wallace, espindola
Subscribers: srhines, emaste, arichardson, kristof.beyls, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D68069
llvm-svn: 373680
Summary:
This change ensures that the .dynsym section will be parsed even when there's already is a .symtab.
It is motivated because of minidebuginfo (https://sourceware.org/gdb/current/onlinedocs/gdb/MiniDebugInfo.html#MiniDebugInfo).
There it says:
Keep all the function symbols not already in the dynamic symbol table.
That means the .symtab embedded inside the .gnu_debugdata does NOT contain the symbols from .dynsym. But in order to put a breakpoint on all symbols we need to load both. I hope this makes sense.
My other patch D66791 implements support for minidebuginfo, that's why I need this change.
Reviewers: labath, espindola, alexshap
Subscribers: JDevlieghere, emaste, arichardson, MaskRay, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D67390
llvm-svn: 371599
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368933
Pavel Labath