Try to revert D113741 once again.
This also reverts 0ac75e82ff (D114705)
as it causes LLDB's lldb-api.lang/cpp/nsimport.TestCppNsImport.py test
failure w/o D113741.
This reverts commit f9607d45f3.
Differential Revision: https://reviews.llvm.org/D116225
I added `PPC32Got2Section` D62464 to support .got2 but did not implement .got2
in another output section.
PR52799 has a linker script placing .got2 in .rodata, which causes a null
pointer dereference because a MergeSyntheticSection's file is nullptr.
Add the support.
The new `lazy` state is the inverse of the previous `LazyObjFile::extracted`.
There are many advantages:
* previously when a LazyObjFile was extracted, a new ObjFile/BitcodeFile was created; now the file is reused, just with `lazy` cleared
* avoid the confusing transfer of `symbols` from LazyObjFile to the new file
* the `incompatible file:` diagnostic is unified with `is incompatible with`
* simpler code, smaller executable (6200+ bytes smaller on x86-64)
* make eager parsing feasible (for parallel section/symbol table initialization)
Currently the singleton `config` is assigned by `config = make<Configuration>()`
and (if `canExitEarly` is false) destroyed by `lld::freeArena`.
`make<Configuration>` allocates a stab with `malloc(4096)`. This both wastes
memory and bloats the executable (every type instantiates `BumpPtrAllocator`
which costs more than 1KiB code on x86-64).
(No need to worry about `clang::no_destroy`. Regular invocations (`canExitEarly`
is true) call `_Exit` via llvm::sys::Process::ExitNoCleanup.)
Reviewed By: lichray
Differential Revision: https://reviews.llvm.org/D116143
Older Go cmd/link used SHT_PROGBITS for .init_array .
Work around the lack of https://golang.org/cl/373734 for a while.
It does not generate .fini_array or .preinit_array
When linking a 1.2G output (nearly no debug info, 2846621 dynamic relocations) using `--threads=8`, I measured
```
9.131462 Total ExecuteLinker
1.449913 Total Write output file
1.445784 Total Write sections
0.657152 Write sections {"detail":".rela.dyn"}
```
This change decreases the .rela.dyn time to 0.25, leading to 4% speed up in the total time.
* The parallelSort is slow because of expensive r_sym/r_offset computation. Cache the values.
* The iteration is slow. Move r_sym/r_addend computation ahead of time and parallelize it.
With the change, the new encodeDynamicReloc is cheap (0.05s). So no need to parallelize it.
Reviewed By: ikudrin
Differential Revision: https://reviews.llvm.org/D115993
Summary: When disassembling, symbolize a branch target operand
to print a label instead of a real address.
Reviewed By: shchenz
Differential Revision: https://reviews.llvm.org/D114492
In 20a895c4be, we introduce `finalizeOptimizationRemarks()` to make sure we flush the diagnostic remarks file in case the linker doesn't call the global destructors before exiting.
In https://reviews.llvm.org/D73597, we add optimization remarks for removed functions for debugging or for detecting dead code.
But there is a case, if PreOptModuleHook or PostInternalizeModuleHook is defined (e.g. `--plugin-opt=emit-llvm` is passed to linker), we do not call `finalizeOptimizationRemarks()`, therefore we will get an incomplete optimization remarks file.
This patch make sure we flush the diagnostic remarks file when PreOptModuleHook or PostInternalizeModuleHook is defined.
Reviewed By: tejohnson, MaskRay
Differential Revision: https://reviews.llvm.org/D115417
writeSections is typically a bottleneck.
This was used to track down the following bottlenecks:
* Output section .rela.dyn (9115d75117)
* Output section .debug_str (3aae04c744)
* posix_fallocate is slow for Linux tmpfs: D115957
Reviewed By: ikudrin
Differential Revision: https://reviews.llvm.org/D115984
GCC's powerpc32 port predefines `PPC` as a macro in GNU C++ mode in some configurations (Linux,
FreeBSD, and some others. See `builtin_define_std ("PPC"); ` in gcc/config/rs6000).
```
% powerpc-linux-gnu-g++ -E -dM -xc++ /dev/null -o - | grep -w PPC
#define PPC 1
```
Fixes https://bugs.gentoo.org/829599
Reviewed By: thesamesam
Differential Revision: https://reviews.llvm.org/D116017
This decreases struct sizes and usually decreases the lld executable
size (39KiB for my x86-64 executable) (unless in some cases smaller
SmallVector leads to more inlining, e.g. StringTableBuilder).
For --gdb-index, there may be memory usage saving.
Fixes#52778.
Probably fixes Chromium crashing on startup on macOS 10.15 (and older) systems
when building with LTO, but I haven't verified that yet.
Differential Revision: https://reviews.llvm.org/D115949
Matches llvm's and clang's /test/CMakeLists.txt, makes it easier to
see in diffs which deps get added, and makes it easier to see if
a given dependency is present or not.
No behavior change.
Only called once. Moving to OutputSections.cpp can make it inlined.
finalizeInputSections can be very hot, especially in -O1 links with much debug info.
Everyone uses -l -L instead of the long option counterparts.
Make help messages attach to -L -l and (--reproduce) use them for response.txt
command line options.
Calling `Allocate` with 0 size (when .symtab is absent, e.g.
`invalid/mips-invalid-options-descriptor.test`) may return a nullptr, which will
crash with -fsanitize=null (the underlying `Allocate` function is
LLVM_ATTRIBUTE_RETURNS_NONNULL).
The SHT_GNU_version index is 16-bit, so the 32-bit value is a waste.
Technically non-default version index 0x7fff uses version index 0xffff,
but it is impossible in practice.
This change decreases sizeof(SymbolUnion) from 80 to 72 on ELF64 platforms.
Memory usage decreases by 1% when linking a large executable.
For large applications that write to map files, writing map files can take quite
a bit of time. Sorting the biggest contributors to link times, writing map files
ranks in at 2nd place, with load input files being the biggest contributor of
link times. Avoiding writing map files on the critical path (and having its own
thread) saves ~2-3 seconds when linking chromium framework on a 16-Core
Intel Xeon W.
```
base diff difference (95% CI)
sys_time 1.617 ± 0.034 1.657 ± 0.026 [ +1.5% .. +3.5%]
user_time 28.536 ± 0.245 28.609 ± 0.180 [ -0.1% .. +0.7%]
wall_time 23.833 ± 0.271 21.684 ± 0.194 [ -9.5% .. -8.5%]
samples 31 24
```
Reviewed By: #lld-macho, oontvoo, int3
Differential Revision: https://reviews.llvm.org/D115416
* Avoid the name truncation quirk in SymbolTable::insert: the truncated name will be replaced by @@ again.
* Allow foo and foo@@v1 in different files to be diagnosed as duplicate definition error (GNU ld behavior)
* Avoid potential redundant strlen on symbol name due to StringRefZ in ObjFile<ELFT>::initializeSymbols
Fangrui Song