This patch improves the ability of a ObjectFileELF instance to read the
.dynamic section. It adds the ability to read the .dynamic section from
the PT_DYNAMIC program header which is useful for ELF files that have no
section headers and for ELF files that are read from memory. It cleans
up the usage of the .dynamic entries so that
ObjectFileELF::ParseDynamicSymbols() is the only code that parses
.dynamic entries, teaches that function the read and store the string
values for each .dynamic entry. We now dump the .dynamic entries in the
output of "image dump objfile". It also cleans up the code that gets the
dynamic string table so that it can grab it from the DT_STRTAB and
DT_STRSZ .dynamic entries for when we have a ELF file with no section
headers or we are reading it from memory.
This patch improves the ability of a ObjectFileELF instance to read the .dynamic section. It adds the ability to read the .dynamic section from the PT_DYNAMIC program header which is useful for ELF files that have no section headers and for ELF files that are read from memory. It cleans up the usage of the .dynamic entries so that ObjectFileELF::ParseDynamicSymbols() is the only code that parses .dynamic entries, teaches that function the read and store the string values for each .dynamic entry. We now dump the .dynamic entries in the output of "image dump objfile". It also cleans up the code that gets the dynamic string table so that it can grab it from the DT_STRTAB and DT_STRSZ .dynamic entries for when we have a ELF file with no section headers or we are reading it from memory.
PT_LOAD and PT_TLS segments are top level sections in the ObjectFileELF
section list. The two segments can often have the same program header
p_vaddr and p_paddr values and this can cause section load list issues
in LLDB if we load the PT_TLS segments. What happens is the
SectionLoadList::m_addr_to_sect, when a library is loaded, will first
map one of the sections named "PT_LOAD[0]" with the load address that
matches the p_vaddr entry from the program header. Then the "PT_TLS[0]"
would come along and try to load this section at the same address. This
would cause the "PT_LOAD[0]" section to be unloaded as the
SectionLoadList::m_addr_to_sect would replace the value for the matching
p_vaddr with the last section to be seen. The sizes of the PT_TLS and
PT_LOAD that have the same p_vaddr value don't need to have the same
byte size, so this could cause lookups to fail for an addresses in the
"PT_LOAD[0]" section or any of its children if the offset is greater
than the offset size of the PT_TLS segment. It could also cause us to
incorrectly attribute addresses from the "PT_LOAD[0]" to the "PT_TLS[0]"
segment when doing lookups for offset that are less than the size of the
PT_TLS segment.
This fix stops us from loading PT_TLS segments in the section load lists
and will prevent the bugs that resulted from this. No addresses the the
DWARF refer to TLS data with a "file address" in any way. They all have
TLS DWARF location expressions to locate these variables. We also don't
have any support for having actual thread specific sections and having
those sections resolve to something different for each thread, so there
currently is no point in loading thread specific sections. Both the
ObjectFileMachO and ObjectFileCOFF both ignore thread specific sections
at the moment, so this brings the ObjectFileELF to parity with those
plug-ins.
I added a test into an existing test to verify that things work as
expected.
Prior to this fix with a real binary, the output of "target dump
section-load-list" would look like this for the old LLDB:
```
// (lldb) target dump section-load-list
// addr = 0x0000000000000000, section = 0x55d46ab8c510: 0xfffffffffffffffd container [0x0000000000000000-0x0000000000000628) r-- 0x00000000 0x00000628 0x00000000 a.out.PT_LOAD[0]
// addr = 0x0000000000001000, section = 0x55d46ab8b0c0: 0xfffffffffffffffc container [0x0000000000001000-0x0000000000001185) r-x 0x00001000 0x00000185 0x00000000 a.out.PT_LOAD[1]
// addr = 0x0000000000002000, section = 0x55d46ac040f0: 0xfffffffffffffffb container [0x0000000000002000-0x00000000000020cc) r-- 0x00002000 0x000000cc 0x00000000 a.out.PT_LOAD[2]
// addr = 0x0000000000003db0, section = 0x55d46ab7cef0: 0xfffffffffffffff6 container [0x0000000000003db0-0x0000000000003db4) r-- 0x00002db0 0x00000000 0x00000000 a.out.PT_TLS[0]
```
And this for the fixed LLDB:
```
// (lldb) target dump section-load-list
// addr = 0x0000000000000000, section = 0x105f0a9a8: 0xfffffffffffffffd container [0x0000000000000000-0x0000000000000628) r-- 0x00000000 0x00000628 0x00000000 a.out.PT_LOAD[0]
// addr = 0x0000000000001000, section = 0x105f0adb8: 0xfffffffffffffffc container [0x0000000000001000-0x0000000000001185) r-x 0x00001000 0x00000185 0x00000000 a.out.PT_LOAD[1]
// addr = 0x0000000000002000, section = 0x105f0af48: 0xfffffffffffffffb container [0x0000000000002000-0x00000000000020cc) r-- 0x00002000 0x000000cc 0x00000000 a.out.PT_LOAD[2]
// addr = 0x0000000000003db0, section = 0x105f0b078: 0xfffffffffffffffa container [0x0000000000003db0-0x0000000000004028) rw- 0x00002db0 0x00000274 0x00000000 a.out.PT_LOAD[3]
```
We can see that previously the "PT_LOAD[3]" segment would be removed
from the section load list, and after the fix it remains and there is on
PT_TLS in the loaded sections.
Currently, LLDB prints out a rather unhelpful error message when passed
a file that it doesn't recognize as an executable.
> error: '/path/to/file' doesn't contain any 'host' platform
> architectures: arm64, armv7, armv7f, armv7k, armv7s, armv7m, armv7em,
> armv6m, armv6, armv5, armv4, arm, thumbv7, thumbv7k, thumbv7s,
> thumbv7f, thumbv7m, thumbv7em, thumbv6m, thumbv6, thumbv5, thumbv4t,
> thumb, x86_64, x86_64, arm64, arm64e
I did a quick search internally and found at least 24 instances of users
being confused by this. This patch improves the error message when it
doesn't recognize the file as an executable, but keeps the existing
error message otherwise, i.e. when it's an object file we understand,
but the current platform doesn't support.
Section unification cannot just use names, because it's valid for ELF
binaries to have multiple sections with the same name. We should check
other section properties too.
Fixes#88001.
rdar://124467787
There are two age fields in a PDB file. One from the PDB Stream and another one
from the DBI stream.
According to https://randomascii.wordpress.com/2011/11/11/source-indexing-is-underused-awesomeness/#comment-34328,
The age in DBI stream is used to against the binary's age. `Pdbstr.exe` is used
to only increment the age from PDB stream without changing the DBI age. I
also verified this by manually changing the DBI age of a PDB file and let
`windbg.exe` to load it. It shows the following logs before and after changing:
Before:
```
SYMSRV: BYINDEX: 0xA
c:\symbols*https://msdl.microsoft.com/download/symbols
nlaapi.pdb
D72AA69CD5ABE5D28C74FADB17DE3F8C1
SYMSRV: PATH: c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
SYMSRV: RESULT: 0x00000000
*** WARNING: Unable to verify checksum for NLAapi.dll
DBGHELP: NLAapi - public symbols
c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
...
```
After:
```
SYMSRV: BYINDEX: 0xA
c:\symbols*https://msdl.microsoft.com/download/symbols
nlaapi.pdb
D72AA69CD5ABE5D28C74FADB17DE3F8C1
SYMSRV: PATH: c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
SYMSRV: RESULT: 0x00000000
DBGHELP: c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb - mismatched pdb
SYMSRV: BYINDEX: 0xB
c:\symbols*https://chromium-browser-symsrv.commondatastorage.googleapis.com
nlaapi.pdb
D72AA69CD5ABE5D28C74FADB17DE3F8C1
SYMSRV: PATH: c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
SYMSRV: RESULT: 0x00000000
DBGHELP: c:\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb - mismatched pdb
SYMSRV: BYINDEX: 0xC
c:\src\symbols*https://msdl.microsoft.com/download/symbols
nlaapi.pdb
D72AA69CD5ABE5D28C74FADB17DE3F8C1
SYMSRV: PATH: c:\src\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
SYMSRV: RESULT: 0x00000000
*** WARNING: Unable to verify checksum for NLAapi.dll
DBGHELP: NLAapi - public symbols
c:\src\symbols\nlaapi.pdb\D72AA69CD5ABE5D28C74FADB17DE3F8C1\nlaapi.pdb
```
So, `windbg.exe` uses the DBI age to detect mismatched pdb, but it still loads
the pdb even if the age mismatched. Probably lldb should do the same and give
some warnings.
This fixes a bug that lldb can't load some windows system pdbs due to mismatched
uuid.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D152189
Windows uses COFF as an object file format and PE/COFF as an executable
file format. They are subtly different and certain elements of a COFF
file may not be present in an executable. Introduce a new plugin to add
support for the COFF object file format which is required to support
loading of modules built with -gmodules. This is motivated by Swift
which serialises debugging information into a PCM which is a COFF object
file.
Differential Revision: https://reviews.llvm.org/D149987
Reviewed By: bulbazord
Allow the ObjectFileELF plugin to resolve R_ARM_ABS32 relocations from AArch32 object files. This fixes https://github.com/llvm/llvm-project/issues/61948
The existing architectures work with RELA-type relocation records that read addend from the relocation entry. REL-type relocations in AArch32 store addend in-place.
The new function doesn't re-use ELFRelocation::RelocAddend32(), because the interface doesn't match: in addition to the relocation entry we need the actual target section memory.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D147642
According to `/usr/include/elf.h` and `lldb/source/Plugins/ObjectFile/ELF/ELFHeader.h`.
For ELF64 relocation, types of `offset` and `addend` should be `elf_addr` and `elf_sxword`.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D145550
Currently ApplyReloctions() deals with different archs' relocation types
together (in a single `switch() {..}`). I think it is incorrect because
different relocation types of different archs may have same enum values.
For example:
`R_LARCH_32` and `R_X86_64_64` are both `1`;
`R_LARCH_64` and `R_X86_64_PC32` are both `2`.
This patch handles each arch in seperate `switch()` to solve the enum
values conflict issue.
And a new test is added for LoongArch64.
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D145462
Both LLD and GNU ld write global/static variables to the COFF symbol
table with `IMAGE_SYM_TYPE_NULL` and `IMAGE_SYM_DTYPE_NULL` type. Map
these symbols as 'Data' type in the symtab to allow these symbols to be
used in expressions and printable.
Reviewed By: labath, DavidSpickett
Differential Revision: https://reviews.llvm.org/D134585
Forwarder exports do not point to a real function or variable. Instead
they point to a string describing which DLL and symbol to forward to.
Any imports which uses them will be redirected by the loader
transparently. These symbols do not have much use in LLDB, but keep them
just in case someone find it useful. Also set a synthesized name with
the forwarder string for informational purpose.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D134518
If a symbol is the same as an export symbol, mark it as 'Additional' to
prevent the duplicated symbol from being repeated in some commands (e.g.
`disas -n func`). If the RVA is the same but exported with a different
name, only synchronize the symbol types.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D134426
- Skip dummy/invalid export symbols.
- Make the export ordinal of export symbols visible when dumping the
symtab.
- Stop setting the 'Debug' flag and set the 'External' flag instead to
better match the meaning of export symbols.
- Try to guess the type (code vs data) of the symbol from section flags.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D134265
This reimplements `ObjectFilePECOFF::ParseSymtab` to replace the manual
data extraction with what `COFFObjectFile` already provides. Also use
`SymTab::AddSymbol` instead of resizing the SymTab then assigning each
elements afterwards.
Previously, ParseSymTab loads symbols from both the COFF symbol table
and the export table, but if there are any entries in the export table,
it overwrites all the symbols already loaded from the COFF symbol table.
Due to the change to use AddSymbols, this no longer happens, and so the
SymTab now contains all symbols from both tables as expected.
The export symbols are now ordered by ordinal, instead of by the name
table order.
In its current state, it is possible for symbols in the COFF symbol
table to be duplicated by those in the export table. This behaviour will
be modified in a separate change.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D134196
I encountered an issue where `p &variable` was finding an incorrect address for
32-bit PIC ELF files loaded into a running process. The problem was that the
R_386_32 ELF relocations were not being applied to the DWARF section, so all
variables in that file were reporting as being at the start of their respective
section. There is an assert that catches this on debug builds, but silently
ignores the issue on non-debug builds.
In this changeset, I added handling for the R_386_32 relocation type to
ObjectFileELF, and a supporting function to ELFRelocation to differentiate
between DT_REL & DT_RELA in ObjectFileELF::ApplyRelocations().
Demonstration of issue:
```
[dmlary@host work]$ cat rel.c
volatile char padding[32] = "make sure var isnt at .data+0";
volatile char var[] = "test";
[dmlary@host work]$ gcc -c rel.c -FPIC -fpic -g -m32
[dmlary@host work]$ lldb ./exec
(lldb) target create "./exec"
Current executable set to '/home/dmlary/src/work/exec' (i386).
(lldb) process launch --stop-at-entry
Process 21278 stopped
* thread #1, name = 'exec', stop reason = signal SIGSTOP
frame #0: 0xf7fdb150 ld-2.17.so`_start
ld-2.17.so`_start:
-> 0xf7fdb150 <+0>: movl %esp, %eax
0xf7fdb152 <+2>: calll 0xf7fdb990 ; _dl_start
ld-2.17.so`_dl_start_user:
0xf7fdb157 <+0>: movl %eax, %edi
0xf7fdb159 <+2>: calll 0xf7fdb140
Process 21278 launched: '/home/dmlary/src/work/exec' (i386)
(lldb) image add ./rel.o
(lldb) image load --file rel.o .text 0x40000000 .data 0x50000000
section '.text' loaded at 0x40000000
section '.data' loaded at 0x50000000
(lldb) image dump symtab rel.o
Symtab, file = rel.o, num_symbols = 13:
Debug symbol
|Synthetic symbol
||Externally Visible
|||
Index UserID DSX Type File Address/Value Load Address Size Flags Name
------- ------ --- --------------- ------------------ ------------------ ------------------ ---------- ----------------------------------
[ 0] 1 SourceFile 0x0000000000000000 0x0000000000000000 0x00000004 rel.c
[ 1] 2 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 2] 3 Invalid 0x0000000000000000 0x50000000 0x0000000000000020 0x00000003
[ 3] 4 Invalid 0x0000000000000025 0x0000000000000000 0x00000003
[ 4] 5 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 5] 6 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 6] 7 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 7] 8 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 8] 9 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 9] 10 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 10] 11 Invalid 0x0000000000000000 0x0000000000000020 0x00000003
[ 11] 12 X Data 0x0000000000000000 0x50000000 0x0000000000000020 0x00000011 padding
[ 12] 13 X Data 0x0000000000000020 0x50000020 0x0000000000000005 0x00000011 var
(lldb) p &var
(volatile char (*)[5]) $1 = 0x50000000
```
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D132954
clang 14 removed -gz=zlib-gnu support and ld.lld/llvm-objcopy removed zlib-gnu
support recently. Remove lldb support by migrating away from
llvm::object::Decompressor::isCompressedELFSection.
The API has another user llvm-dwp, so it is not removed in this patch.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D129724
When an object file returns multiple architectures, it is treated
as a fat binary - which really isn't the case of i386 vs i686 where
the object file actually has one architecture.
This allows getting rid of hardcoded architecture triples in
PlatformWindows.
The parallel i386 and i686 architecture strings stem from
5e6f45201f / D7120 and
ad587ae4ca / D4658.
Differential Revision: https://reviews.llvm.org/D128617
The setting `plugin.object-file.pe-coff.module-abi` is a string-to-enum
map that allows specifying an ABI to a module name. For example:
ucrtbase.dll=msvc
libstdc++-6.dll=gnu
This allows for debugging a process which mixes both modules built using
the MSVC ABI and modules built using the MinGW ABI.
Depends on D127048
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D127234
25c8a061c5 / D127048 added an option
for setting the ABI to GNU.
When an object file is loaded, there's only minimal verification
done for the architecture spec set for it, if the object file only
provides one.
However, for i386 object files, the PECOFF object file plugin
provides two architectures, i386-pc-windows and i686-pc-windows.
This picks a totally different codepath in
TargetList::CreateTargetInternal, where it's treated as a fat
binary. This goes through more verifications to see if the
architectures provided by the object file matches what the
platform plugin supports.
The PlatformWindows() constructor explicitly adds the
"i386-pc-windows" and "i686-pc-windows" architectures (even when
running on other architectures), which allows this "fat binary
verification" to succeed for the i386 object files that provide
two architectures.
However, after that commit, if the object file is advertised with
the different environment (either when lldb is built in a mingw
environment, or if that setting is set), the fat binary validation
won't accept the file any longer.
Update ArchSpec::IsEqualTo with more logic for the Windows use
cases; mismatching vendors is not an issue (they don't have any
practical effect on Windows), and GNU and MSVC environments are
compatible to the point that PlatformWindows can handle object
files for both environments/ABIs.
As a separate path forward, one could also consider to stop returning
two architecture specs from ObjectFilePECOFF::GetModuleSpecifications
for i386 files.
Differential Revision: https://reviews.llvm.org/D128268
PE/COFF can use either MSVC or GNU (MinGW) ABI for C++ code, however
LLDB had defaulted to MSVC implicitly with no way to override it. This
causes issues when debugging modules built with the GNU ABI, sometimes
even crashes.
This changes the PE/COFF plugin to set the module triple according to
the default target triple used to build LLDB. If the default target
triple is Windows and a valid environment is specified, then this
environment will be used for the module spec. This not only works for
MSVC and GNU, but also other environments.
A new setting, `plugin.object-file.pe-coff.abi`, has been added to
allow overriding this default ABI.
* Fixes https://github.com/llvm/llvm-project/issues/50775
* Fixes https://github.com/mstorsjo/llvm-mingw/issues/226
* Fixes https://github.com/mstorsjo/llvm-mingw/issues/282
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D127048
The specification of gnu-debuglink can be found at:
https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
The file CRC or the CRC value from the .gnu_debuglink section is now
used to calculate the module UUID as a fallback, to allow verifying that
the debug object does match the executable. Note that if a CodeView
build id exists, it still takes precedence. This works even for MinGW
builds because LLD writes a synthetic CodeView build id which does not
get stripped from the debug object.
The `Minidump/Windows/find-module` test also needs a fix by adding a
CodeView record to the exe to match the one in the minidump, otherwise
it fails due to the new UUID calculated from the file CRC.
Fixes https://github.com/llvm/llvm-project/issues/54344
Reviewed By: DavidSpickett
Differential Revision: https://reviews.llvm.org/D126367
(With C++ exceptions, `clang++ --target=mips64{,el}-linux-gnu -fpie -pie
-fuse-ld=lld` has link errors (lld does not implement some strange R_MIPS_64
.eh_frame handling in GNU ld). However, sanitizer-x86_64-linux-qemu used this to
build ScudoUnitTests. Pined ScudoUnitTests to -no-pie.)
Default the option introduced in D113372 to ON to match all(?) major Linux
distros. This matches GCC and improves consistency with Android and linux-musl
which always default to PIE.
Note: CLANG_DEFAULT_PIE_ON_LINUX may be removed in the future.
Differential Revision: https://reviews.llvm.org/D120305
(The upgrade of the ppc64le bot and D121257 have fixed compiler-rt failures. Tested by nemanjai.)
Default the option introduced in D113372 to ON to match all(?) major Linux
distros. This matches GCC and improves consistency with Android and linux-musl
which always default to PIE.
Note: CLANG_DEFAULT_PIE_ON_LINUX may be removed in the future.
Differential Revision: https://reviews.llvm.org/D120305
See post-commit discussion on https://reviews.llvm.org/D120305.
This change breaks the clang-ppc64le-rhel buildbot, though
there is suspicion that it's an issue with the bot. The change
also had a larger than expected impact on compile-time and
code-size.
This reverts commit 3c4ed02698
and some followup changes.
minidebuginfo-set-and-hit-breakpoint.test is failing on Arm/Linux most
probably due to an ill formed binary after removal of certain sections
from executable. I am marking it as XFAIL for further investigation.
Only lldb-arm-ubuntu is failing after https://reviews.llvm.org/D114288 and there isn't enough input context to see why this is failing. It works on x86_64 linux just fine.
LLDB build were failing due to following two test failures:
lldb-shell :: ObjectFile/ELF/basic-info.yaml
lldb-shell :: SymbolFile/DWARF/x86/debug-types-address-ranges.s
There were caused by commit 6506907a0a
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.
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.
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
D95354 started to set the sh_link field for SHT_SYMTAB sections.
Previously it was set for symbol tables basing on their names (e.g. ".symtab").
This test now crashes see:
http://lab.llvm.org:8011/#/builders/68/builds/5911
I updated it to restore the old behavior.
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
