Add options --set-symbol-visibility and --set-symbols-visibility to
manually change the visibility of symbols.
There is already an option to set the visibility of newly added symbols
via --add-symbol and --new-symbol-visibility. This option will allow to
change the visibility of already existing symbols.
This patch adds a LLVM-EXEGESIS-LOOP-REGISTER snippet annotation which
allows a user to specify the register to use for the loop counter in the
loop repetition mode. This allows for executing snippets that don't work
with the default value (currently R8 on X86).
Primary change is to add a flag `--pretty-pgo-analysis-map` to
llvm-readobj and llvm-objdump that prints block frequencies and branch
probabilities in the same manner as BFI and BPI respectively. This can
be helpful if you are manually inspecting the outputs from the tools.
In order to print, I moved the `printBlockFreqImpl` function from
Analysis to Support and renamed it to `printRelativeBlockFreq`.
https://reviews.llvm.org/D63820 added
llvm/docs/CommandGuide/llvm-objcopy.rst with clearer semantics, e.g.
```
Read a list of names from the file <filename> and mark defined symbols with those names as global in the output
instead of the help message
Read a list of symbols from <filename> and marks them global" (omits "defined")
Rename sections called <old> to <new> in the output
instead of the help message
Rename a section from old to new (multiple sections may be named <old>
```
Sync the help messages to incorporate the CommandGuide improvement.
While here, switch to the conventional imperative sentences for a few
options. Additionally, mark some options as grp_coff or grp_macho.
When a section has the SHF_COMPRESSED flag, -p/-x dump the compressed
content by default. In GNU readelf, if --decompress/-z is specified,
-p/-x will dump the decompressed content. This patch implements the
option.
Close#82507
This patch replaces --num-repetitions with --min-instructions to make it
more clear that the value refers to the minimum number of instructions
in the final assembled snippet rather than the number of repetitions of
the snippet. This patch also refactors some llvm-exegesis internal
variable names to reflect the name change.
Fixes#76890.
This patch adds two new repetition modes to llvm-exegesis, particularly
loop and duplicate repetition modes of what I am terming the middle half
repetition mode. The middle half repetition mode essentially runs each
measurement twice, one with twice the number of iterations of the other.
These two measurements are then agregated by taking their difference.
This subtracts away any setup/overhead that is unrelated to the code in
the snippet, providing more accurate results.
Using this mode on a couple toy examples, I am able to get exact
(integer) throughput values on all of them in contrast to the default
duplicate/loop repetition modes which show a little bit of noise on the
snippet value.
`--function=<regex>` Include functions matching regex in the output
`--no-function=<regex>` Exclude functions matching regex from the output
If both are specified, `--no-function` has a higher precedence if a
function name matches both filters
Added -p / --no-params flag to skip demangling function parameters
similar to how it is supported by GNU c++filt tool.
There are cases when users want to demangle a large number of symbols in
bulk, for example, at startup, and do not care about function parameters
and overloads at that time. Skipping the demangling of parameter types
led to a measurable improvement in performance. Our users reported about
15% speed up with GNU c++filt and we expect similar results with
llvm-cxxfilt with this patch.
Added -p / --no-params flag to skip demangling function parameters
similar to how it is supported by GNU c++filt tool.
There are cases when users want to demangle a large number of symbols in
bulk, for example, at startup, and do not care about function parameters
and overloads at that time. Skipping the demangling of parameter types
led to a measurable improvement in performance. Our users reported about
15% speed up with GNU c++filt and we expect similar results with
llvm-cxxfilt with this patch.
This patch makes minor adjustments to the llvm-exegesis docs for
clarity. Particularly, an update is made to the list of snippet
annotations to list the correct number of annotations that was not
updated when the docs were originally updated for the snippet address
annotation. In addition, this patch changes a decimal value for the
snippet memory annotation example for an explicit hex value to emphasize
that the LLVM-EXEGESIS-MEM-DEF annotation takes a hex value for the
memory value.
When llvm-objdump switched from cl:: to OptTable
(https://reviews.llvm.org/D100433), we dropped support for LLVM cl::
options. Some LLVM_DEBUG in `llvm/lib/Target/$target/MCDisassembler/`
files might be useful. Add -mllvm to allow dumping the information.
```
# -debug is available in an LLVM_ENABLE_ASSERTIONS=on build
llvm-objdump -d -mllvm -debug a.o > /dev/null
```
Link:
https://discourse.llvm.org/t/how-to-enable-debug-logs-in-llvm-objdump/75758
`--gap-fill <value>` fills the gaps between sections with a specified
8-bit value, instead of zero.
`--pad-to <address>` pads the output binary up to the specified load
address, using the 8-bit value from `--gap-fill` or zero.
These options are only supported for ELF input and binary output.
## Motivation
Since we don't need the metadata sections at runtime, we can somehow
offload them from memory at runtime. Initially, I explored [debug info
correlation](https://discourse.llvm.org/t/instrprofiling-lightweight-instrumentation/59113),
which is used for PGO with value profiling disabled. However, it
currently only works with DWARF and it's be hard to add such artificial
debug info for every function in to CodeView which is used on Windows.
So, offloading profile metadata sections at runtime seems to be a
platform independent option.
## Design
The idea is to use new section names for profile name and data sections
and mark them as metadata sections. Under this mode, the new sections
are non-SHF_ALLOC in ELF. So, they are not loaded into memory at runtime
and can be stripped away as a post-linking step. After the process
exits, the generated raw profiles will contains only headers + counters.
llvm-profdata can be used correlate raw profiles with the unstripped
binary to generate indexed profile.
## Data
For chromium base_unittests with code coverage on linux, the binary size
overhead due to instrumentation reduced from 64M to 38.8M (39.4%) and
the raw profile files size reduce from 128M to 68M (46.9%)
```
$ bloaty out/cov/base_unittests.stripped -- out/no-cov/base_unittests.stripped
FILE SIZE VM SIZE
-------------- --------------
+121% +30.4Mi +121% +30.4Mi .text
[NEW] +14.6Mi [NEW] +14.6Mi __llvm_prf_data
[NEW] +10.6Mi [NEW] +10.6Mi __llvm_prf_names
[NEW] +5.86Mi [NEW] +5.86Mi __llvm_prf_cnts
+95% +1.75Mi +95% +1.75Mi .eh_frame
+108% +400Ki +108% +400Ki .eh_frame_hdr
+9.5% +211Ki +9.5% +211Ki .rela.dyn
+9.2% +95.0Ki +9.2% +95.0Ki .data.rel.ro
+5.0% +87.3Ki +5.0% +87.3Ki .rodata
[ = ] 0 +13% +47.0Ki .bss
+40% +1.78Ki +40% +1.78Ki .got
+12% +1.49Ki +12% +1.49Ki .gcc_except_table
[ = ] 0 +65% +1.23Ki .relro_padding
+62% +1.20Ki [ = ] 0 [Unmapped]
+13% +448 +19% +448 .init_array
+8.8% +192 [ = ] 0 [ELF Section Headers]
+0.0% +136 +0.0% +80 [7 Others]
+0.1% +96 +0.1% +96 .dynsym
+1.2% +96 +1.2% +96 .rela.plt
+1.5% +80 +1.2% +64 .plt
[ = ] 0 -99.2% -3.68Ki [LOAD #5 [RW]]
+195% +64.0Mi +194% +64.0Mi TOTAL
$ bloaty out/cov-cor/base_unittests.stripped -- out/no-cov/base_unittests.stripped
FILE SIZE VM SIZE
-------------- --------------
+121% +30.4Mi +121% +30.4Mi .text
[NEW] +5.86Mi [NEW] +5.86Mi __llvm_prf_cnts
+95% +1.75Mi +95% +1.75Mi .eh_frame
+108% +400Ki +108% +400Ki .eh_frame_hdr
+9.5% +211Ki +9.5% +211Ki .rela.dyn
+9.2% +95.0Ki +9.2% +95.0Ki .data.rel.ro
+5.0% +87.3Ki +5.0% +87.3Ki .rodata
[ = ] 0 +13% +47.0Ki .bss
+40% +1.78Ki +40% +1.78Ki .got
+12% +1.49Ki +12% +1.49Ki .gcc_except_table
+13% +448 +19% +448 .init_array
+0.1% +96 +0.1% +96 .dynsym
+1.2% +96 +1.2% +96 .rela.plt
+1.2% +64 +1.2% +64 .plt
+2.9% +64 [ = ] 0 [ELF Section Headers]
+0.0% +40 +0.0% +40 .data
+1.2% +32 +1.2% +32 .got.plt
+0.0% +24 +0.0% +8 [5 Others]
[ = ] 0 -22.9% -872 [LOAD #5 [RW]]
-74.5% -1.44Ki [ = ] 0 [Unmapped]
[ = ] 0 -76.5% -1.45Ki .relro_padding
+118% +38.8Mi +117% +38.8Mi TOTAL
```
A few things to note:
1. llvm-profdata doesn't support filter raw profiles by binary id yet,
so when a raw profile doesn't belongs to the binary being digested by
llvm-profdata, merging will fail. Once this is implemented,
llvm-profdata should be able to only merge raw profiles with the same
binary id as the binary and discard the rest (with mismatched/missing
binary id). The workflow I have in mind is to have scripts invoke
llvm-profdata to get all binary ids for all raw profiles, and
selectively choose the raw pnrofiles with matching binary id and the
binary to llvm-profdata for merging.
2. Note: In COFF, currently they are still loaded into memory but not
used. I didn't do it in this patch because I noticed that `.lcovmap` and
`.lcovfunc` are loaded into memory. A separate patch will address it.
3. This should works with PGO when value profiling is disabled as debug
info correlation currently doing, though I haven't tested this yet.
Recent versions of GNU binutils starting from 2.39 support symbol+offset
lookup in addition to the usual numeric address lookup. This change adds
symbol lookup to llvm-symbolize and llvm-addr2line.
Now llvm-symbolize behaves closer to GNU addr2line, - if the value specified
as address in command line or input stream is not a number, it is treated as
a symbol name. For example:
llvm-symbolize --obj=abc.so func_22
llvm-symbolize --obj=abc.so "CODE func_22"
This lookup is now supported only for functions. Specification with
offset is not supported yet.
This is a recommit of 2b27948783e4bbc1132d3220d8517ef62607b558, reverted
in 39fec5457c0925bd39f67f63fe17391584e08258 because the test
llvm/test/Support/interrupts.test started failing on Windows. The test was
changed in 18f036d0105589c3175bb51a518c5d272dae61e2 and is also updated in
this commit.
Differential Revision: https://reviews.llvm.org/D149759
This reverts commit 122c89b271af30b86536cad7bac64ea9c56615ed. Change does not build, with errors such as:
In file included from ../llvm-project/llvm/tools/dsymutil/DebugMap.h:24,
from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:60:17: error: declaration of ‘llvm::dsymutil::SymbolMapping llvm::dsymutil::ValidReloc::SymbolMapping’ changes meaning of ‘SymbolMapping’ [-fpermissive]
60 | SymbolMapping SymbolMapping;
| ^~~~~~~~~~~~~
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:36:8: note: ‘SymbolMapping’ declared here as ‘struct llvm::dsymutil::SymbolMapping’
36 | struct SymbolMapping {
| ^~~~~~~~~~~~~
In file included from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/DebugMap.h:198:32: error: declaration of ‘std::optional<llvm::dsymutil::RelocationMap> llvm::dsymutil::DebugMapObject::RelocationMap’ changes meaning of ‘RelocationMap’ [-fpermissive]
198 | std::optional<RelocationMap> RelocationMap;
| ^~~~~~~~~~~~~
In file included from ../llvm-project/llvm/tools/dsymutil/DebugMap.h:24,
from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.h:13,
from ../llvm-project/llvm/tools/dsymutil/DwarfLinkerForBinary.cpp:9:
../llvm-project/llvm/tools/dsymutil/RelocationMap.h:76:7: note: ‘RelocationMap’ declared here as ‘class llvm::dsymutil::RelocationMap’
76 | class RelocationMap {
| ^~~~~~~~~~~~~
This adds support in dsymutil for mergeable libraries [1].
dsymutil reads a new stab emitted by ld, allowing it to operate on
dynamic libraries instead of object files. It also now loads the DWARF
files associated to the libraries, and build the debug map for each
binary from the list of symbols exported by the library. For each Debug
Map Object, there is a new associated Relocation Map which is serialized
from the information retrieved in the original debug_info (or
debug_addr) section of the .o file.
The final DWARF file has multiple compile units, so the offsets
information of the relocations are adjusted relatively to the compile
unit they will end up belonging to, inside the final linked DWARF file.
[1] https://developer.apple.com/documentation/xcode/configuring-your-project-to-use-mergeable-libraries
Differential revision: https://reviews.llvm.org/D158124
This tool is a generic remark counter reporting count based on specified
properties. The counter can be used to count remarks individually and
filter them based on name, type and pass or count using remark
arguments.
Recent versions of GNU binutils starting from 2.39 support symbol+offset
lookup in addition to the usual numeric address lookup. This change adds
symbol lookup to llvm-symbolize and llvm-addr2line.
Now llvm-symbolize behaves closer to GNU addr2line, - if the value specified
as address in command line or input stream is not a number, it is treated as
a symbol name. For example:
llvm-symbolize --obj=abc.so func_22
llvm-symbolize --obj=abc.so "CODE func_22"
This lookup is now supported only for functions. Specification with
offset is not supported yet.
Differential Revision: https://reviews.llvm.org/D149759
Remove the paper trail warning from dsymutil and the DWARF linker. The
original purpose of this functionality was to leave a paper trail in the
output artifact about missing object files. The current implementation
however has diverged and is the source of a pretty serious bug:
- In the debug map parser, missing object files are not the only
warnings we emit. When paper trail warnings are enabled, all of them end
up in the dSYM which wasn't the goal.
- When warnings are associated with a object file in the debug map, it
is skipped by the DWARF linker. This only makes sense if the object file
is missing and is obviously incorrect for any other type of warning
(such as a missing symbol).
The combination of the two means that we can generate broken DWARF when
the feature is enabled. AFAIK it was only used by Apple and nobody I
spoke to has relied on it, so rather than fixing the broken behavior I
propose we remove it.
This parallels the binutils/BSD flag of the same name. Debugging
information is loaded to print line number information for symbols.
Defined symbols are symbolized by their section addresses, and undefined
symbols by their first text reloc with line info.
Differential Revision: https://reviews.llvm.org/D150987
This patch and D154984 were discussed in
<https://discourse.llvm.org/t/rfc-improving-lits-debug-output/72839>.
Motivation
----------
D154984 removes the "Script:" section that lit prints along with a
test's output, and it makes -v and -a imply -vv. For example, after
D154984, the "Script:" section below is never shown, but -v is enough
to produce the execution trace following it:
```
Script:
--
: 'RUN: at line 1'; echo hello | FileCheck bogus.txt && echo success
--
Exit Code: 2
Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "echo" "hello"
# command output:
hello
$ "FileCheck" "bogus.txt"
# command stderr:
Could not open check file 'bogus.txt': No such file or directory
error: command failed with exit status: 2
--
```
In the D154984 review, some reviewers point out that they have been
using the "Script:" section for copying and pasting a test's shell
commands to a terminal window. The shell commands as printed in the
execution trace can be harder to copy and paste for the following
reasons:
- They drop redirections and break apart RUN lines at `&&`, `|`, etc.
- They add `$` at the start of every command, which makes it hard to
copy and paste multiple commands in bulk.
- Command stdout, stderr, etc. are interleaved with the commands and
are not clearly delineated.
- They don't always use proper shell quoting. Instead, they blindly
enclose all command-line arguments in double quotes.
Changes
-------
D154984 plus this patch converts the above example into:
```
Exit Code: 2
Command Output (stdout):
--
# RUN: at line 1
echo hello | FileCheck bogus-file.txt && echo success
# executed command: echo hello
# .---command stdout------------
# | hello
# `-----------------------------
# executed command: FileCheck bogus-file.txt
# .---command stderr------------
# | Could not open check file 'bogus-file.txt': No such file or directory
# `-----------------------------
# error: command failed with exit status: 2
--
```
Thus, this patch addresses the above issues as follows:
- The entire execution trace can be copied and pasted in bulk to a
terminal for correct execution of the RUN lines, which are printed
intact as they appeared in the original RUN lines except lit
substitutions are expanded. Everything else in the execution trace
appears in shell comments so it has no effect in a terminal.
- Each of the RUN line's commands is repeated (in shell comments) as
it executes to show (1) that the command actually executed (e.g.,
`echo success` above didn't) and (2) what stdout, stderr, non-zero
exit status, and output files are associated with the command, if
any. Shell quoting in the command is now correct and minimal but is
not necessarily the original shell quoting from the RUN line.
- The start and end of the contents of stdout, stderr, or an output
file is now delineated clearly in the trace.
To help produce some of the above output, this patch extends lit's
internal shell with a built-in `@echo` command. It's like `echo`
except lit suppresses the normal execution trace for `@echo` and just
prints its stdout directly. For now, `@echo` isn't documented for use
in lit tests.
Without this patch, libcxx's custom lit test format tries to parse the
stdout from `lit.TestRunner.executeScriptInternal` (which runs lit's
internal shell) to extract the stdout and stderr produced by shell
commands, and that parse no longer works after the above changes.
This patch makes a small adjustment to
`lit.TestRunner.executeScriptInternal` so libcxx can just request
stdout and stderr without an execution trace.
(As a minor drive-by fix that came up in testing: lit's internal `not`
command now always produces a numeric exit status and never `True`.)
Caveat
------
This patch only makes the above changes for lit's internal shell. In
most cases, we do not know how to force external shells (e.g., bash,
sh, window's `cmd`) to produce execution traces in the manner we want.
To configure a test suite to use lit's internal shell (which is
usually better for test portability than external shells anyway), add
this to the test suite's `lit.cfg` or other configuration file:
```
config.test_format = lit.formats.ShTest(execute_external=False)
```
Reviewed By: MaskRay, awarzynski
Differential Revision: https://reviews.llvm.org/D156954
This patch and D156954 were discussed in
<https://discourse.llvm.org/t/rfc-improving-lits-debug-output/72839>.
**Motivation**: -a shows output from all tests, and -v shows output
from just failed tests. Without this patch, that output from each
test includes a section called "Script:", which includes all shell
commands that lit has computed from RUN directives and will attempt to
run for that test. The effect of -vv (which also implies -v if
neither -a or -v is specified) is to extend that output with shell
commands as they are executing so you can easily see which one failed.
For example, when using lit's internal shell and -vv:
```
Script:
--
: 'RUN: at line 1'; echo hello world
: 'RUN: at line 2'; 3c40 hello world
: 'RUN: at line 3'; echo hello world
--
Exit Code: 127
Command Output (stdout):
--
$ ":" "RUN: at line 1"
$ "echo" "hello" "world"
hello world
$ ":" "RUN: at line 2"
$ "3c40" "hello" "world"
'3c40': command not found
error: command failed with exit status: 127
--
```
Notice that all shell commands that actually execute appear in the
output twice, once for "Script:" and once for -vv. Especially for
tests with many RUN directives, the result is noisy. When searching
through the output for a particular shell command, it is easy to get
lost and mistake shell commands under "Script:" for shell commands
that actually executed.
**Change**: With this patch, a test's output changes in two ways.
First, the "Script:" section is never shown. Second, omitting -vv no
longer disables printing of shell commands as they execute. That is,
-a and -v imply -vv, and so -vv is deprecated as it is just an alias
for -v.
**Secondary motivation**: We are also working to introduce a PYTHON
directive, which can appear between RUN directives. How should PYTHON
directives be represented in the "Script:" section, which has
previously been just a shell script? We could probably think of
something, but adding info about PYTHON directive execution in the -vv
trace seems more straight-forward and more useful.
(This patch also removes a confusing point in the -vv documentation:
at least when using bash as an external shell, -vv echoes commands to
the shell's stderr not stdout.)
Reviewed By: awarzynski, Endill, ldionne, MaskRay
Differential Revision: https://reviews.llvm.org/D154984
GNU readelf introduced --extra-sym-info/-X to display the section name
for --syms (https://sourceware.org/PR30684). Port the feature, which is
currently llvm-readelf only.
For STO_AARCH64_VARIANT_PCS/STO_RISCV_VARIANT_PCS, the Ndx and Name
columns may not be aligned.
Enable color highlighting of disassembly in llvm-objdump. This patch
introduces a new flag --disassembler-color=<mode> that enables or
disables highlighting disassembly with ANSI escape codes. The default
mode is to enable color highlighting if outputting to a color-enabled
terminal.
Differential revision: https://reviews.llvm.org/D159224
Add support for syntax highlighting assembly. The patch introduces new
RAII helper called WithMarkup that takes care of both emitting colors
and markup annotations. It makes adding markup easier and ensures colors
and annotations remain consistent.
This patch adopts the new helper in the AArch64 backend. If your backend
already uses markup annotations, adoption is as easy as using the new
MCInstPrinter::markup overload.
Differential revision: https://reviews.llvm.org/D159162
