Identify dynamically exported symbols (--export-dynamic[-symbol=],
--dynamic-list=, or definitions needed to preempt shared objects) and
prevent their LTO visibility from being upgraded.
This helps avoid use of whole program devirtualization when there may
be overrides in dynamic libraries.
Differential Revision: https://reviews.llvm.org/D91583
FaultsMapParser lived in CodeGen and was forcing llvm-objdump to
link CodeGen and everything CodeGen depends on.
This was previously attempted in r240364 to fix a link failure.
The CodeGen dependency was independently added to fix the same
link failure, and that ended up being kept.
Removing the dependency seems like the correct layering for
llvm-objdump.
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D95414
There are two use cases.
Assembler
We have accrued some code gated on MCAsmInfo::useIntegratedAssembler(). Some
features are supported by latest GNU as, but we have to use
MCAsmInfo::useIntegratedAs() because the newer versions have not been widely
adopted (e.g. SHF_LINK_ORDER 'o' and 'unique' linkage in 2.35, --compress-debug-sections= in 2.26).
Linker
We want to use features supported only by LLD or very new GNU ld, or don't want
to work around older GNU ld. We currently can't represent that "we don't care
about old GNU ld". You can find such workarounds in a few other places, e.g.
Mips/MipsAsmprinter.cpp PowerPC/PPCTOCRegDeps.cpp X86/X86MCInstrLower.cpp
AArch64 TLS workaround for R_AARCH64_TLSLD_MOVW_DTPREL_* (PR ld/18276),
R_AARCH64_TLSLE_LDST8_TPREL_LO12 (https://bugs.llvm.org/show_bug.cgi?id=36727https://sourceware.org/bugzilla/show_bug.cgi?id=22969)
Mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER components (supported by LLD in D84001;
GNU ld feature request https://sourceware.org/bugzilla/show_bug.cgi?id=16833 may take a while before available).
This feature allows to garbage collect some unused sections (e.g. fragmented .gcc_except_table).
This patch adds `-fbinutils-version=` to clang and `-binutils-version` to llc.
It changes one codegen place in SHF_MERGE to demonstrate its usage.
`-fbinutils-version=2.35` means the produced object file does not care about GNU
ld<2.35 compatibility. When `-fno-integrated-as` is specified, the produced
assembly can be consumed by GNU as>=2.35, but older versions may not work.
`-fbinutils-version=none` means that we can use all ELF features, regardless of
GNU as/ld support.
Both clang and llc need `parseBinutilsVersion`. Such command line parsing is
usually implemented in `llvm/lib/CodeGen/CommandFlags.cpp` (LLVMCodeGen),
however, ClangCodeGen does not depend on LLVMCodeGen. So I add
`parseBinutilsVersion` to `llvm/lib/Target/TargetMachine.cpp` (LLVMTarget).
Differential Revision: https://reviews.llvm.org/D85474
A default version (@@) is only available for defined symbols.
Currently we use "@@" for undefined symbols too.
This patch fixes the issue and improves our test case.
Differential revision: https://reviews.llvm.org/D95219
The llvm-dwp tool hard-codes the target triple to x86. Instead, deduce the
target triple from the object files being read.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D93749
This was discussed in D93678 thread.
Currently we have one special chunk - Fill.
This patch re implements the "SectionHeaderTable" key to become a special chunk too.
With that we are able to place the section header table at any location,
just like we place sections.
Differential revision: https://reviews.llvm.org/D95140
To simplify the transition to using LTOBackend, move DisableVerify to
the LTOCodeGenerator class, like most/all other options.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95223
This patch adds a new InstModificationIRStrategy to mutate flags/options
for instructions. For example, it may add or remove nuw/nsw flags from
add, mul, sub, shl instructions or change the predicate for icmp
instructions.
Subtle changes such as those mentioned above should lead to a more
interesting range of inputs. The presence or absence of overflow flags
can expose subtle bugs, for example.
Reviewed By: bogner
Differential Revision: https://reviews.llvm.org/D94905
The target features are obtained as a list of features/attributes.
Instead of storing them in a single string, store the vector. This
matches lto::Config's behavior and simplifies the transition to
lto::backend().
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D95224
lto::Config has a field to control whether the build is "freestanding"
(no builtins) or not, but it is not hooked up to the code actually
running the passes.
This patch adds support for the flag to both the code that runs
optimization with the new and old pass managers, by explicitly adding a
TargetLibraryInfo instance. If Freestanding is true, all library functions
are disabled.
Reviewed By: steven_wu
Differential Revision: https://reviews.llvm.org/D94630
We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.
PR48779
Initially reverted due to BasicAA running analyses in an unspecified
order (multiple function calls as parameters), fixed by fetching
analyses before the call to construct BasicAA.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D95117
We tend to assume that the AA pipeline is by default the default AA
pipeline and it's confusing when it's empty instead.
PR48779
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D95117
This makes the following improvements.
For `SHT_GNU_versym`:
* yaml2obj: set `sh_link` to index of `.dynsym` section automatically.
For `SHT_GNU_verdef`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version definitions.
For `SHT_GNU_verneed`:
* yaml2obj: set `sh_link` to index of `.dynstr` section automatically.
* yaml2obj: set `sh_info` field automatically.
* obj2yaml: don't dump the `Info` field when its value matches the number of version dependencies.
Also, simplifies few test cases.
Differential revision: https://reviews.llvm.org/D94956
The modification time in the debug map is expressed using second
precision, while the modification time returned by the filesystem could
be more precise. Avoid spurious warnings about timestamp mismatches by
truncating the modification time reported by the system to seconds.
Linking large bitcode archives currently takes a lot of time with llvm-link,
this patch adds couple improvements which reduce link time for archives
- Use one Linker instance for archive instead of recreating it for each member
- Lazy load archive members
Reviewed By: tra, jdoerfert
Differential Revision: https://reviews.llvm.org/D94643
In preparation for turning on opt's -enable-new-pm by default, this pins
uses of passes via the legacy "opt -passname" with pass names beginning
with "polly-" and "polyhedral-info" to the legacy PM. Many of these
tests use -analyze, which isn't supported in the new PM.
(This doesn't affect uses of "opt -passes=passname").
rL240766 accidentally removed `-polly-prepare` in
phi_not_grouped_at_top.ll, and it also doesn't use the output of
-analyze.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D94266
`ELFDumper.cpp` implements the functionality that allows to get symbol versions.
It is used for dumping versioned symbols.
This helps to implement https://bugs.llvm.org/show_bug.cgi?id=48670 ("make llvm-nm -D print version names"):
we can move out and reuse the code from `ELFDumper.cpp`.
This is what this patch do: it moves the related functionality to `ELFFile<ELFT>`.
Differential revision: https://reviews.llvm.org/D94771
This patch removes some ancient options as a clean-up before moving
code-gen to use LTOBackend in D94487.
I think it would preferable to remove those ancient options, because
1. There are no corresponding options in LTOBackend based tools,
2. There are no unit tests for them,
3. They are not passed through by Clang,
4. At least for GNVLoadPRE, users could just use GVN's `enable-load-pre`.
Alternatively we could add support for those options to lto::Config &
co, but I think it would be better to remove them, unless they are
actually used in practice.
Reviewed By: steven_wu, tejohnson
Differential Revision: https://reviews.llvm.org/D94783
It is possible to simplify the logic that extracts symbol names.
D94667 made the `NMSymbol::Name` to be `std::string`,
what allowed this simplification.
Differential revision: https://reviews.llvm.org/D94669
`dumpSymbolNamesFromObject` is the method that dumps symbol names.
It has 563 lines, mostly because of huge piece of MachO specific code.
In this patch I move it to separate helper method.
The new size of `dumpSymbolNamesFromObject` is 93 lines. With it it becomes
much easier to maintain it.
I had to change the type of 2 name fields to `std::string`, because MachO logic
uses temporarily buffer strings (e.g `ExportsNameBuffer`, `BindsNameBuffer` etc):
```
std::string ExportsNameBuffer;
raw_string_ostream EOS(ExportsNameBuffer);
```
these buffers were moved to `dumpSymbolsFromDLInfoMachO` by this patch and
invalidated after return. Technically, before this patch we had a situation
when local pointers (symbol names) were assigned to members of global static `SymbolList`,
what is dirty by itself.
Differential revision: https://reviews.llvm.org/D94667
This addressed post commit comments for D93900.
GCC had an issue and requires placing a specialization of
`printUnwindInfo` to a namespace to compile:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480
This commit adds table symbol support in a partial way, while still
including some special cases for the __indirect_function_table symbol.
No change in tests.
Differential Revision: https://reviews.llvm.org/D94075
This change extends virtual unwinder to support pseudo probe in llvm-profgen. Please refer https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s and https://reviews.llvm.org/D89707 for more context about CSSPGO and llvm-profgen.
**Implementation**
- Added `ProbeBasedCtxKey` derived from `ContextKey` for sample counter aggregation. As we need string splitting to infer the profile for callee function, string based context introduces more string handling overhead, here we just use probe pointer based context.
- For linear unwinding, as inline context is encoded in each pseudo probe, we don't need to go through each instruction to extract range sharing same inliner. So just record the range for the context.
- For probe based context, we should ignore the top frame probe since it will be extracted from the address range. we defer the extraction in `ProfileGeneration`.
- Added `PseudoProbeProfileGenerator` for pseudo probe based profile generation.
- Some helper function to get pseduo probe info(call probe, inline context) from profiled binary.
- Added regression test for unwinder's output
The pseudo probe based profile generation will be in the upcoming patch.
Test Plan:
ninja & ninja check-llvm
Differential Revision: https://reviews.llvm.org/D92896
As we plan to support both CSSPGO and AutoFDO for llvm-profgen, we will have different kinds of perf sample and different kinds of sample counter(cs/non-cs, with/without pseudo probe) which both need to do aggregation in hash map. This change implements the hashable interface(`Hashable`) and the unified base class for them to have better extensibility and reusability.
Currently perf trace sample and sample counter with context implemented this `Hashable` and the class hierarchy is like:
```
| Hashable
| PerfSample
| HybridSample
| LBRSample
| ContextKey
| StringBasedCtxKey
| ProbeBasedCtxKey
| CallsiteBasedCtxKey
| ...
```
- Class specifying `Hashable` should implement `getHashCode` and `isEqual`. Here we make `getHashCode` a non-virtual function to avoid vtable overhead, so derived class should calculate and assign the base class's HashCode manually. This also provides the flexibility for calculating the hash code incrementally(like rolling hash) during frame stack unwinding
- `isEqual` is a virtual function, which will have perf overhead. In the future, if we redesign a better hash function, then we can just skip this or switch to non-virtual function.
- Added `PerfSample` and `ContextKey` as base class for perf sample and counter context key, leveraging llvm-style RTTI for this.
- Added `StringBasedCtxKey` class extending `ContextKey` to use string as context id.
- Refactor `AggregationCounter` to take all kinds of `PerfSample` as key
- Refactor `ContextSampleCounter` to take all kinds of `ContextKey` as key
- Other refactoring work:
- Create a wrapper class `SampleCounter` to wrap `RangeCounter` and `BranchCounter`
- Hoist `ContextId` and `FunctionProfile` out of `populateFunctionBodySamples` and `populateFunctionBoundarySamples` to reuse them in ProfileGenerator
Differential Revision: https://reviews.llvm.org/D92584
This change implements pseudo probe decoding and disassembling for llvm-profgen/CSSPGO. Please see https://groups.google.com/g/llvm-dev/c/1p1rdYbL93s and https://reviews.llvm.org/D89707 for more context about CSSPGO and llvm-profgen.
**ELF section format**
Please see the encoding patch(https://reviews.llvm.org/D91878) for more details of the format, just copy the example here:
Two section(`.pseudo_probe_desc` and `.pseudoprobe` ) is emitted in ELF to support pseudo probe.
The format of `.pseudo_probe_desc` section looks like:
```
.section .pseudo_probe_desc,"",@progbits
.quad 6309742469962978389 // Func GUID
.quad 4294967295 // Func Hash
.byte 9 // Length of func name
.ascii "_Z5funcAi" // Func name
.quad 7102633082150537521
.quad 138828622701
.byte 12
.ascii "_Z8funcLeafi"
.quad 446061515086924981
.quad 4294967295
.byte 9
.ascii "_Z5funcBi"
.quad -2016976694713209516
.quad 72617220756
.byte 7
.ascii "_Z3fibi"
```
For each `.pseudoprobe` section, the encoded binary data consists of a single function record corresponding to an outlined function (i.e, a function with a code entry in the `.text` section). A function record has the following format :
```
FUNCTION BODY (one for each outlined function present in the text section)
GUID (uint64)
GUID of the function
NPROBES (ULEB128)
Number of probes originating from this function.
NUM_INLINED_FUNCTIONS (ULEB128)
Number of callees inlined into this function, aka number of
first-level inlinees
PROBE RECORDS
A list of NPROBES entries. Each entry contains:
INDEX (ULEB128)
TYPE (uint4)
0 - block probe, 1 - indirect call, 2 - direct call
ATTRIBUTE (uint3)
reserved
ADDRESS_TYPE (uint1)
0 - code address, 1 - address delta
CODE_ADDRESS (uint64 or ULEB128)
code address or address delta, depending on ADDRESS_TYPE
INLINED FUNCTION RECORDS
A list of NUM_INLINED_FUNCTIONS entries describing each of the inlined
callees. Each record contains:
INLINE SITE
GUID of the inlinee (uint64)
ID of the callsite probe (ULEB128)
FUNCTION BODY
A FUNCTION BODY entry describing the inlined function.
```
**Disassembling**
A switch `--show-pseudo-probe` is added to use along with `--show-disassembly` to print disassembly code with pseudo probe directives.
For example:
```
00000000002011a0 <foo2>:
2011a0: 50 push rax
2011a1: 85 ff test edi,edi
[Probe]: FUNC: foo2 Index: 1 Type: Block
2011a3: 74 02 je 2011a7 <foo2+0x7>
[Probe]: FUNC: foo2 Index: 3 Type: Block
[Probe]: FUNC: foo2 Index: 4 Type: Block
[Probe]: FUNC: foo Index: 1 Type: Block Inlined: @ foo2:6
2011a5: 58 pop rax
2011a6: c3 ret
[Probe]: FUNC: foo2 Index: 2 Type: Block
2011a7: bf 01 00 00 00 mov edi,0x1
[Probe]: FUNC: foo2 Index: 5 Type: IndirectCall
2011ac: ff d6 call rsi
[Probe]: FUNC: foo2 Index: 4 Type: Block
2011ae: 58 pop rax
2011af: c3 ret
```
**Implementation**
- `PseudoProbeDecoder` is added in ProfiledBinary as an infra for the decoding. It decoded the two section and generate two map: `GUIDProbeFunctionMap` stores all the `PseudoProbeFunction` which is the abstraction of a general function. `AddressProbesMap` stores all the pseudo probe info indexed by its address.
- All the inline info is encoded into binary as a trie(`PseudoProbeInlineTree`) and will be constructed from the decoding. Each pseudo probe can get its inline context(`getInlineContext`) by traversing its inline tree node backwards.
Test Plan:
ninja & ninja check-llvm
Differential Revision: https://reviews.llvm.org/D92334
This re-lands e5553b9a6a with two small fixes to the tests:
- Don't touch the source directory in debug-map-parsing.test but
instead copy everything over in a temporary directory in
timestamp-mismatch.test.
- Don't redirect stderr to stdout to avoid the output getting
intertwined in extern-alias.test.
This reverts commit e5553b9a6a.
Tests are not allowed to modify the source. Please figure out a way to
use %t rather than dynamically modifying the inputs.
This reuses the code from yaml2obj (moves it to ELFYAML.h).
With it we can set the `sh_entsize` in a single place in `obj2yaml`.
Note that it also fixes a bug of `yaml2obj`: we do not
set the `sh_entsize` field for the `SHT_ARM_EXIDX` section properly.
Differential revision: https://reviews.llvm.org/D93858
Teresa Johnson