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.
These tests fail if you build without the x86 llvm backend.
Either because they use an x86 triple or try to backtrace which
requires some x86 knowledge to see all frames.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D100194
`image dump symtab` seems to output the symbols in whatever order they appear in
the DenseMap that is used to filter out symbols with non-unique addresses. As
DenseMap is a hash map this order can change at any time so the output of this
command is pretty unstable. This also causes the `Breakpad/symtab.test` to fail
with enabled reverse iteration (which reverses the DenseMap order to find issues
like this).
This patch makes the DenseMap a std::vector and uses a separate DenseSet to do
the address filtering. The output order is now dependent on the order in which
the symbols are read (which should be deterministic). It might also avoid a bit
of work as all the work for creating the Symbol constructor parameters is only
done when we can actually emplace a new Symbol.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D87036
Update the "image show-unwind" command output to show if the function
being shown is listed as a user-setting or platform trap handler.
Update the individual UnwindPlan dumps to show whether the unwind plan
is registered as a trap handler.
The llvm DWARFExpression dump is nearly identical, but better -- for
example it does print a spurious space after zero-argument expressions.
Some parts of our code (variable locations) have been already switched
to llvm-based expression dumping. This switches the remainder: unwind
plans and some unit tests.
In breakpad, only x86 (and mips) registers have a leading '$' in their
names. Arm architectures use plain register names.
Previously, lldb was assuming all registers have a '$'. Fix the code to
match the (unfortunately, inconsistent) reality.
The reason is to add .yaml as a valid test suffix. The test folder
contains one yaml file, which wasn't being run because of that.
Unsurprisingly the test fails, but this was not because the underlying
functionality was broken, but rather because the test was setup
incorrectly (most likely due to overly aggressive simplification of the
test data on my part).
Therefore this patch also tweaks the test inputs in order to test what
they are supposed to test, and also updates some other breakpad tests
(because they depend on the same inputs as this one) to be more
realistic -- specifically it avoids putting symbols to the first page of
the module, as that's where normally the COFF header would reside.
Explicit dynsym/dynstr sections were added in a6370d5 to compensate for
a yaml2obj change D74764. This test doesn't need those sections, so
instead I just delete the explicit section blocks, and also the
"DynamicSymbols" block, which triggers their implicit generation.
D74764 (https://reviews.llvm.org/rG31f2ad9c368d47721508cbd0d120d626f9041715)
changed the behavior of the yaml2obj. Now it assigns virtual addresses
for allocatable sections.
SymbolFile/Breakpad/symtab.test started to fail after this change:
(http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/5520/steps/test/logs/stdio)
Command Output (stderr):
--
/home/worker/lldb-x86_64-debian/lldb-x86_64-debian/llvm-project/lldb/test/Shell/SymbolFile/Breakpad/symtab.test:6:10: error: CHECK: expected string not found in input
# CHECK: Symtab, file = {{.*}}symtab.out, num_symbols = 5:
^
<stdin>:15:1: note: scanning from here
Symtab, file = /home/worker/lldb-x86_64-debian/lldb-x86_64-debian/build/tools/lldb/test/SymbolFile/Breakpad/Output/symtab.out, num_symbols = 6:
^
<stdin>:15:99: note: possible intended match here
Symtab, file = /home/worker/lldb-x86_64-debian/lldb-x86_64-debian/build/tools/lldb/test/SymbolFile/Breakpad/Output/symtab.out, num_symbols = 6:
For now I've updated the basic-elf.yaml so that now it produce the same layout as before D74764.
Breakpad/symtab.test should be updated it seems.
Summary:
Not all minidumps contain information about memory permissions. However,
it is still important to know which regions of memory contain
potentially executable code. This is particularly important for
unwinding on win32, as the default unwind method there relies on
scanning the stack for things which "look like" code pointers.
This patch enables ProcessMinidump to reconstruct the likely permissions
of memory regions using the sections of loaded object files. It only
does this if we don't have a better source (memory info list stream, or
linux /proc/maps) for this information, and only if the information in
the object files does not conflict with the information in the minidump.
Theoretically that last bit could be improved, since the permissions
obtained from the MemoryList streams is also only a very rough guess,
but it did not seem worthwhile to complicate the implementation because
of that because there will generally be no overlap in practice as the
MemoryList will contain the stack contents and not any module data.
The patch adds a test checking that the module section permissions are
entered into the memory region list, and also a test which demonstrate
that now the unwinder is able to correctly find return addresses even in
minidumps without memory info list streams.
There's one TODO left in this patch, which is that the "memory region"
output does not give any indication about the "don't know" values of
memory region permissions (it just prints them as if they permission bit
was set). I address this in a follow up.
Reviewers: amccarth, clayborg
Subscribers: mgrang, lldb-commits
Differential Revision: https://reviews.llvm.org/D69105
LLDB has three major testing strategies: unit tests, tests that exercise
the SB API though dotest.py and what we currently call lit tests. The
later is rather confusing as we're now using lit as the driver for all
three types of tests. As most of this grew organically, the directory
structure in the LLDB repository doesn't really make this clear.
The 'lit' tests are part of the root and among these tests there's a
Unit and Suite folder for the unit and dotest-tests. This layout makes
it impossible to run just the lit tests.
This patch changes the directory layout to match the 3 testing
strategies, each with their own directory and their own configuration
file. This means there are now 3 directories under lit with 3
corresponding targets:
- API (check-lldb-api): Test exercising the SB API.
- Shell (check-lldb-shell): Test exercising command line utilities.
- Unit (check-lldb-unit): Unit tests.
Finally, there's still the `check-lldb` target that runs all three test
suites.
Finally, this also renames the lit folder to `test` to match the LLVM
repository layout.
Differential revision: https://reviews.llvm.org/D68606
llvm-svn: 374184
Greg Clayton