The bitstream reader handles errors poorly. This has two effects:
* Bugs in file handling (especially modules) manifest as an "unexpected end of
file" crash
* Users of clang as a library end up aborting because the code unconditionally
calls `report_fatal_error`
The bitstream reader should be more resilient and return Expected / Error as
soon as an error is encountered, not way late like it does now. This patch
starts doing so and adopting the error handling where I think it makes sense.
There's plenty more to do: this patch propagates errors to be minimally useful,
and follow-ups will propagate them further and improve diagnostics.
https://bugs.llvm.org/show_bug.cgi?id=42311
<rdar://problem/33159405>
Differential Revision: https://reviews.llvm.org/D63518
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This command prints a description of the referenced function's stack frame.
For each formal parameter and local variable, the tool prints:
- function name
- variable name
- file/line of declaration
- FP-relative variable location (if available)
- size in bytes
- HWASAN tag offset
This information will be used by the HWASAN runtime to identify local
variables in UAR reports.
Differential Revision: https://reviews.llvm.org/D63468
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We do not need the elf-groups.x86_64. In one of the tests, it was
used for no solid reason, and for the second test case we can use
YAML input with SHT_GROUP sections.
The patch performs a cleanup of one of the test cases, removes another
one completely (since during the review was found out it actually
duplicates one of the existent tests) and removes the precompiled binary.
Differential revision: https://reviews.llvm.org/D63647
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-d code.
Summary:
Move it into `main` function so the checking is effective for all actions
user may do with llvm-objdump; notably, -r and -s in addition to existing -d.
Match GNU behavior.
Reviewers: jhenderson, grimar, MaskRay, rupprecht
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63631
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We do not have to spread using the precompiled binaries in the tests,
when we can use YAML. This patch removes the dynrel.elf binary and adds
a few comments to the test cases.
Differential revision: https://reviews.llvm.org/D63641
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This patch teaches the bottleneck analysis how to identify and print the most
expensive sequence of instructions according to the simulation. Fixes PR37494.
The goal is to help users identify the sequence of instruction which is most
critical for performance.
A dependency graph is internally used by the bottleneck analysis to describe
data dependencies and processor resource interferences between instructions.
There is one node in the graph for every instruction in the input assembly
sequence. The number of nodes in the graph is independent from the number of
iterations simulated by the tool. It means that a single node of the graph
represents all the possible instances of a same instruction contributed by the
simulated iterations.
Edges are dynamically "discovered" by the bottleneck analysis by observing
instruction state transitions and "backend pressure increase" events generated
by the Execute stage. Information from the events is used to identify critical
dependencies, and materialize edges in the graph. A dependency edge is uniquely
identified by a pair of node identifiers plus an instance of struct
DependencyEdge::Dependency (which provides more details about the actual
dependency kind).
The bottleneck analysis internally ranks dependency edges based on their impact
on the runtime (see field DependencyEdge::Dependency::Cost). To this end, each
edge of the graph has an associated cost. By default, the cost of an edge is a
function of its latency (in cycles). In practice, the cost of an edge is also a
function of the number of cycles where the dependency has been seen as
'contributing to backend pressure increases'. The idea is that the higher the
cost of an edge, the higher is the impact of the dependency on performance. To
put it in another way, the cost of an edge is a measure of criticality for
performance.
Note how a same edge may be found in multiple iteration of the simulated loop.
The logic that adds new edges to the graph checks if an equivalent dependency
already exists (duplicate edges are not allowed). If an equivalent dependency
edge is found, field DependencyEdge::Frequency of that edge is incremented by
one, and the new cost is cumulatively added to the existing edge cost.
At the end of simulation, costs are propagated to nodes through the edges of the
graph. The goal is to identify a critical sequence from a node of the root-set
(composed by node of the graph with no predecessors) to a 'sink node' with no
successors. Note that the graph is intentionally kept acyclic to minimize the
complexity of the critical sequence computation algorithm (complexity is
currently linear in the number of nodes in the graph).
The critical path is finally computed as a sequence of dependency edges. For
edges describing processor resource interferences, the view also prints a
so-called "interference probability" value (by dividing field
DependencyEdge::Frequency by the total number of iterations).
Examples of critical sequence computations can be found in tests added/modified
by this patch.
On output streams that support colored output, instructions from the critical
sequence are rendered with a different color.
Strictly speaking the analysis conducted by the bottleneck analysis view is not
a critical path analysis. The cost of an edge doesn't only depend on the
dependency latency. More importantly, the cost of a same edge may be computed
differently by different iterations.
The number of dependencies is discovered dynamically based on the events
generated by the simulator. However, their number is not fixed. This is
especially true for edges that model processor resource interferences; an
interference may not occur in every iteration. For that reason, it makes sense
to also print out a "probability of interference".
By construction, the accuracy of this analysis (as always) is strongly dependent
on the simulation (and therefore the quality of the information available in the
scheduling model).
That being said, the critical sequence effectively identifies a performance
criticality. Instructions from that sequence are expected to have a very big
impact on performance. So, users can take advantage of this information to focus
their attention on specific interactions between instructions.
In my experience, it works quite well in practice, and produces useful
output (in a reasonable amount time).
Differential Revision: https://reviews.llvm.org/D63543
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Many LLVM-based tools already support response files (i.e. files
containing a list of options, specified with '@'). This change simply
updates the documentation and help text for some of these tools to
include it. I haven't attempted to fix all tools, just a selection that
I am interested in.
I've taken the opportunity to add some tests for --help behaviour, where
they were missing. We could expand these tests, but I don't think that's
within scope of this patch.
This fixes https://bugs.llvm.org/show_bug.cgi?id=42233 and
https://bugs.llvm.org/show_bug.cgi?id=42236.
Reviewed by: grimar, MaskRay, jkorous
Differential Revision: https://reviews.llvm.org/D63597
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--help and -h are automatically supported by the command-line parser,
unless overridden by the tool. The behaviour of the PrintHelpMessage
being used for -h prior to this patch is subtly different to that
provided by --help automatically (it omits certain elements of help text
and options, such as --help-list), so overriding the default is not
desirable, without good reason. This patch removes the explicit
specification of -h and its behaviour, so that the default behaviour is
used.
Reviewed by: hintonda
Differential Revision: https://reviews.llvm.org/D63565
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The ARMDisassembler changes allow changing between ARM and Thumb mode
based on the MCSubtargetInfo, rather than the Target, which simplifies
the other changes a bit.
I'm not really happy with adding more target-specific logic to
tools/llvm-objdump/, but there isn't any easy way around it: the logic
in question specifically applies to disassembling an object file, and
that code simply isn't located in lib/Target, at least at the moment.
Differential Revision: https://reviews.llvm.org/D60927
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The original line was there from when this test was added, but it is
checking for a switch that doesn't exist, so really has no purpose, at
least any more.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363833 91177308-0d34-0410-b5e6-96231b3b80d8
The check against the output of `od` in the affected tests expect a
specific input offset format. They also expect a specific offset value,
not consistent with the EXAMPLE section for `od` in POSIX.1-2017
Chapter 4, while using the `-j` option. In particular, the example shows
that the input offset begins at 0 following the bytes skipped.
This patch adjusts the matching of the input offset to be more generic.
In order to avoid false matches, it restricts the number of bytes to be
formatted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363829 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
llvm.x86.sse.stmxcsr only writes to memory.
llvm.x86.sse.ldmxcsr only reads from memory, and might generate an FPE.
Reviewers: craig.topper, RKSimon
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62896
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Summary:
Historically llvm-objdump prints the path to a dylib as well as the
dylib's compatibility version and current version number. This change
extends this information by adding the kind of dylib load: weak,
reexport, etc.
rdar://51383512
Reviewers: pete, lhames
Reviewed By: pete
Subscribers: rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62866
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1) `-x foo` currently dumps one `foo`. This change makes it dump all `foo`.
2) `-x foo -x foo` currently dumps `foo` twice. This change makes it dump `foo` once.
In addition, if foo has section index 9, `-x foo -x 9` dumps `foo` once.
3) Give a warning instead of an error if `foo` does not exist.
The new behaviors match GNU readelf.
Also, print a new line as a separator between two section dumps.
GNU readelf uses two lines, but one seems good enough.
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D63475
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Summary: Implements bug [[ https://bugs.llvm.org/show_bug.cgi?id=42204 | 42204 ]]. llvm-strip now warns when the same input file is used more than once, and errors when stdin is used more than once.
Reviewers: jhenderson, rupprecht, espindola, alexshap
Reviewed By: jhenderson, rupprecht
Subscribers: emaste, arichardson, jakehehrlich, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63122
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Use -fsave-optimization-record=<format> to specify a different format
than the default, which is YAML.
For now, only YAML is supported.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363573 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The "sparc"/"sparcel" architectures appears in ArchMap (used by -B option) but not in OutputFormatMap (used by -I/-O option). Add their targets into OutputFormatMap for consistency.
Note that AFAIK there're no targets for 32-bit little-endian SPARC ("elf32-sparcel") in GNU binutils.
Reviewers: espindola, alexshap, rupprecht, jhenderson, compnerd, jakehehrlich
Reviewed By: jhenderson, compnerd, jakehehrlich
Subscribers: jyknight, emaste, arichardson, fedor.sergeev, jakehehrlich, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63238
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This adds:
* documentation to the user manual
* nicer error message
* test for the error case
* test for the gold plugin
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LLD test case will be fixed in a following commit.
Original commit message:
[yaml2obj] - Allow setting custom section types for implicit sections.
We were hardcoding the final section type for sections that
are usually implicit. The patch fixes that.
This also fixes a few issues in existent test cases and removes
one precompiled object.
Differential revision: https://reviews.llvm.org/D63267
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This reverts commit r363377 because lld's ELF/invalid/undefined-local-symbol-in-dso.test
test started failing after this commit.
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We were hardcoding the final section type for sections that
are usually implicit. The patch fixes that.
This also fixes a few issues in existent test cases and removes
one precompiled object.
Differential revision: https://reviews.llvm.org/D63267
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363377 91177308-0d34-0410-b5e6-96231b3b80d8
Despite the fact that .strtab is non-allocatable,
there is no reason to disallow setting the custom address
for it.
The patch also adds a test case showing we can set any address
we want for other implicit sections.
Differential revision: https://reviews.llvm.org/D63137
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Sam Clegg